Dissociative disorders and possession experiences in Israel: a comparison of opiate use disorder patients, Arab women subjected to domestic violence, and a nonclinical group.

PubMed

Somer, Eli; Ross, Colin; Kirshberg, Revital; Bakri, Rana Shawahdy; Ismail, Shefa

2015-02-01

This study examined the association between exposure to domestic violence and dissociative symptoms. A sample of 68 Israeli opiate use disorder patients in recovery, 80 battered Arab Israeli women, and 103 respondents from a community sample participated in structured interviews that included the Dissociative Disorders Interview Schedule (DDIS), the Dissociative Trance Disorder Interview Schedule (DTDIS), and the Dissociative Experiences Scale (DES). As predicted, community participants reported significantly less exposure to traumatizing events and lower levels of dissociative psychopathology than individuals sampled from specialized treatment centers. In all, 91% of battered female participants were taxon-positive for dissociative disorder with 1 of every 2 respondents reporting symptoms corresponding to dissociative amnesia and depersonalization disorder, suggesting that this group may be particularly vulnerable to dissociative psychopathology. Extrasensory and paranormal experiences (ESP) and dissociative trance disorder experiences were strongly related to dissociative experiences and features of dissociative identity disorder (DID). These statistical associations suggest that dissociative disorders and ESP/trance experiences may share an underlying construct. Further research is needed on trauma and dissociation among female victims of domestic abuse in patriarchal, collectivist societies, particularly in the Arab world. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Assessment of dissociation in Bosnian treatment-seeking refugees in Denmark.

PubMed

Palic, Sabina; Carlsson, Jessica; Armour, Cherie; Elklit, Ask

2015-05-01

Dissociative experiences are common in traumatized individuals, and can sometimes be mistaken for psychosis. It is difficult to identify pathological dissociation in the treatment of traumatized refugees, because there is a lack of systematic clinical descriptions of dissociative phenomena in refugees. Furthermore, we are currently unaware of how dissociation measures perform in this clinical group. To describe the phenomenology of dissociative symptoms in Bosnian treatment-seeking refugees in Denmark. As a part of a larger study, dissociation was assessed systematically in 86 Bosnian treatment-seeking refugees using a semi-structured clinical interview (Structured Interview for Disorders of Extreme Stress-dissociation subscale; SIDES-D) and a self-report scale (Dissociative Experiences Scale; DES). The SIDES-D indicated twice as high prevalence of pathological dissociation as the DES. According to the DES, 30% of the refugees had pathological dissociation 15 years after their resettlement. On the SIDES-D, depersonalization and derealization experiences were the most common. Also, questions about depersonalization and derealization at times elicited reporting of visual and perceptual hallucinations, which were unrelated to traumatic re-experiencing. Questions about personality alteration elicited spontaneous reports of a phenomenon of "split" pre- and post-war identity in the refugee group. Whether this in fact is a dissociative phenomenon, characteristic of severe traumatization in adulthood, needs further examination. Knowledge of dissociative symptoms in traumatized refugees is important in clinical settings to prevent misclassification and to better target psychotherapeutic interventions. Much development in the measurement of dissociation in refugees is needed.

A Validation Study of the Adolescent Dissociative Experiences Scale

ERIC Educational Resources Information Center

Keck Seeley, Susan. M.; Perosa, Sandra, L.; Perosa, Linda, M.

2004-01-01

Objective: The purpose of this study was to further the validation process of the Adolescent Dissociative Experiences Scale (A-DES). In this study, a 6-item Likert response format with descriptors was used when responding to the A-DES rather than the 11-item response format used in the original A-DES. Method: The internal reliability and construct…

The Contribution of Art Therapy to the Dissociative Disorders.

ERIC Educational Resources Information Center

Murphy, Patricia S.

1994-01-01

Explored concepts of brain hemispheric lateralization and distinct right brain functioning in extensive dissociation by administering Dissociative Experiences Scale to 114 engineering students and 92 university drawing students. Chi-square calculation found differences in dissociative scoring levels between groups that approached significance at…

Dissociation in Psychiatric Disorders: A Meta-Analysis of Studies Using the Dissociative Experiences Scale.

PubMed

Lyssenko, Lisa; Schmahl, Christian; Bockhacker, Laura; Vonderlin, Ruben; Bohus, Martin; Kleindienst, Nikolaus

2018-01-01

Dissociation is a complex, ubiquitous construct in psychopathology. Symptoms of dissociation are present in a variety of mental disorders and have been connected to higher burden of illness and poorer treatment response, and not only in disorders with high levels of dissociation. This meta-analysis offers a systematic and evidence-based study of the prevalence and distribution of dissociation, as assessed by the Dissociative Experiences Scale, within different categories of mental disorders, and it updates an earlier meta-analysis. More than 1,900 original publications were screened, and 216 were included in the meta-analysis, comprising 15,219 individuals in 19 diagnostic categories. The largest mean dissociation scores were found in dissociative disorders (mean scores >35), followed by posttraumatic stress disorder, borderline personality disorder, and conversion disorder (mean scores >25). Somatic symptom disorder, substance-related and addictive disorders, feeding and eating disorders, schizophrenia, anxiety disorder, OCD, and most affective disorders also showed mean dissociation scores >15. Bipolar disorders yielded the lowest dissociation scores (mean score, 14.8). The findings underline the importance of careful psychopathological assessment of dissociative symptoms in the entire range of mental disorders.

Is there a complex relation between social anxiety disorder, childhood traumatic experiences and dissociation?

PubMed

Belli, Hasan; Akbudak, Mahir; Ural, Cenk; Solmaz, Mustafa; Dogan, Zuhal; Konkan, Ramazan

2017-01-01

A possible relationship has been suggested between social anxiety and dissociation. Traumatic experiences, especially childhood abuse, play an important role in the aetiology of dissociation. This study assesses childhood trauma history, dissociative symptoms, and dissociative disorder comorbidity in patients with social anxiety disorder (SAD). The 94 psychotropic drug-naive patients participating in the study had to meet DSM-IV criteria for SAD. Participants were assessed using the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D), the Dissociation Questionnaire (DIS-Q), the Liebowitz Social Anxiety Scale (LSAS), and the Childhood Trauma Questionnaire (CTQ). Patients were divided into two groups using the DIS-Q, and the two groups were compared. The evaluation found evidence of at least one dissociative disorder in 31.91% of participating patients. The most prevalent disorders were dissociative disorder not otherwise specified (DDNOS), dissociative amnesia, and depersonalization disorders. Average scores on LSAS and fear and avoidance sub-scale averages were significantly higher among the high DIS-Q group (p < .05). In a logistic regression taking average LSAS scores as the dependent variable, the five independent variables DIS-Q, CTQ-53 total score, emotional abuse, sexual abuse, and emotional neglect were associated with average LSAS scores among patients with SAD (p < .05). It is concluded that, on detecting SAD symptoms during hospitalization, the clinician should not neglect underlying dissociative processes and traumatic experiences among these patients.

Dissociative Experiences of Sexual Offenders: A Comparison between Two Outpatient Groups and Those Found to be Falsely Accused.

ERIC Educational Resources Information Center

Dwyer, S. Margretta

1992-01-01

Administered Dissociative Experiences Scale, which distinguishes between subjects with dissociative disorder and those without, to 71 sex offenders and 14 men who were falsely accused of sexual abuse. Outpatient sex offenders scored in the range attributed to general population. Those falsely accused of child sexual abuse scored lower than…

[Dissociative symptoms in patients with mood and anxiety disorders].

PubMed

Moscariello, Marianna Margherita; Ratti, Flavia; Quartini, Adele; Forcén, Fernando Espí; Munuera, Joaquin Nieto; Bersani, Giuseppe

2010-01-01

The objective of this study was to evaluate the occurrence of dissociative symptoms in outpatients affected by mood or anxiety disorder and their potential implication in general psychopathology and treatment response. The sample was recruited at Italian and Spanish psychiatric outpatient services. The sample consisted in 40 (13 Male, 27 Female) outpatients, 22 Italians (55%) and 18 Spanish (45%). Inclusion criteria were the Axis I diagnosis of any DSM-IV-TR mood or anxiety disorder and Clinical Global Impression/Global Severity Index (CGI) baseline scores > or = 3 and Hamilton Depression Rating Scale (HAM-D) and Hamilton Anxiety Scale (HAM-A) baseline scores > or = 18. General psychopathology, dissociative symptoms and personality traits were respectively assessed by the self-report symptom inventory Symptom Check-List 90 (SCL-90), the Dissociative Experience Scale (DES) and the Cloninger's Temperament and Character Inventory (TCI). Dissociative symptoms emerged as relatively frequent in mood and anxiety disorders. Globally, depression symptoms seem to correlate positively with the dissociative experiences and the severity of global psychopathology. Dissociative symptoms seem to correlate positively with some personality traits and the severity of global psychopathology and should receive further investigation in clinical practice, as might be a predictor of poor response to conventional drug treatment.

Reality versus fantasy: reply to Lynn et al. (2014).

PubMed

Dalenberg, Constance J; Brand, Bethany L; Loewenstein, Richard J; Gleaves, David H; Dorahy, Martin J; Cardeña, Etzel; Frewen, Paul A; Carlson, Eve B; Spiegel, David

2014-05-01

We respond to Lynn et al.'s (2014) comments on our review (Dalenberg et al., 2012) demonstrating the superiority of the trauma model (TM) over the fantasy model (FM) in explaining the trauma-dissociation relationship. Lynn et al. conceded that our meta-analytic results support the TM hypothesis that trauma exposure is a causal risk factor for the development of dissociation. Although Lynn et al. suggested that our meta-analyses were selective, we respond that each omitted study failed to meet inclusion criteria; our meta-analyses thus reflect a balanced view of the predominant trauma-dissociation findings. In contrast, Lynn et al. were hypercritical of studies that supported the TM while ignoring methodological problems in studies presented as supportive of the FM. We clarify Lynn et al.'s misunderstandings of the TM and demonstrate consistent superiority in prediction of time course of dissociative symptoms, response to psychotherapy of dissociative patients, and pattern of relationships of trauma to dissociation. We defend our decision not to include studies using the Dissociative Experiences Scale-Comparison, a rarely used revision of the Dissociative Experiences Scale that shares less than 10% of the variance with the original scale. We highlight several areas of agreement: (a) Trauma plays a complex role in dissociation, involving indirect and direct paths; (b) dissociation-suggestibility relationships are small; and (c) controls and measurement issues should be addressed in future suggestibility and dissociation research. Considering the lack of evidence that dissociative individuals simply fantasize trauma, future researchers should examine more complex models of trauma and valid measures of dissociation.

Spontaneous and deliberate dissociative states in military personnel: are such states helpful?

PubMed

Morgan, Charles A; Taylor, Marcus K

2013-08-01

This study explored distinctions between spontaneous and deliberate dissociative states in 335 military personnel exposed to stressful survival training. Participants completed the Clinician-Administered Dissociative States Scale (CADSS) after a stressful mock-captivity event. They were also asked to indicate whether the dissociative experiences just happened (i.e., spontaneous), or whether they chose to have them happen (i.e., deliberate); and whether they appraised the dissociative experience as helpful (i.e., facilitative) or hurtful (i.e., debilitative) to their ability to cope with the stressful event. A majority (95.4%) endorsed dissociative states during stress. More than half (57.4%) described dissociative experiences as spontaneous, 13.0% as deliberate, and 29.5% endorsed neither. In Special Forces soldiers only, those who endorsed facilitative dissociation exhibited higher total CADSS scores than those who endorsed debilitative dissociation. Seventy-three percent of spontaneous dissociators described the experience as debilitative to coping with stress; conversely, 76% of deliberate dissociators said these experiences facilitated coping with stress. Individuals with prior trauma exposure tended to appraise dissociative states as more debilitative to coping. This research may enhance the fidelity of studies of dissociation constructs and may offer pivot points for prevention and treatment of stress-related disorders. Published 2013. This article is a US Government work and is in the public domain in the USA.

Childhood Traumatic Experiences, Dissociative Symptoms, and Dissociative Disorder Comorbidity Among Patients With Panic Disorder: A Preliminary Study.

PubMed

Ural, Cenk; Belli, Hasan; Akbudak, Mahir; Tabo, Abdulkadir

2015-01-01

This study assessed childhood trauma history, dissociative symptoms, and dissociative disorder comorbidity in patients with panic disorder (PD). A total of 92 psychotropic drug-naive patients with PD, recruited from outpatient clinics in the psychiatry department of a Turkish hospital, were involved in the study. Participants were assessed using the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D), Dissociation Questionnaire, Panic and Agoraphobia Scale, Panic Disorder Severity Scale, and Childhood Trauma Questionnaire. Of the patients with PD, 18 (19%) had a comorbid dissociative disorder diagnosis on screening with the SCID-D. The most prevalent disorders were dissociative disorder not otherwise specified, dissociative amnesia, and depersonalization disorders. Patients with a high degree of dissociation symptoms and dissociative disorder comorbidity had more severe PD than those without (p < .05). All of the childhood trauma subscales used were correlated with the severity of symptoms of dissociation and PD. Among all of the subscales, the strongest relationship was with childhood emotional abuse. Logistic regression analysis showed that emotional abuse and severity of PD were independently associated with dissociative disorder. In our study, a significant proportion of the patients with PD had concurrent diagnoses of dissociative disorder. We conclude that the predominance of PD symptoms at admission should not lead the clinician to overlook the underlying dissociative process and associated traumatic experiences among these patients.

Empirical testing of criteria for dissociative schizophrenia.

PubMed

Laferrière-Simard, Marie-Christine; Lecomte, Tania; Ahoundova, Lola

2014-01-01

This study examined the validity of dissociative schizophrenia diagnostic criteria. In the first phase, 50 participants with a psychotic disorder were administered the Dissociative Experiences Scale and the Childhood Trauma Questionnaire to identify those with dissociative characteristics. In the second phase, we selected those who had a score of 15 or above on the Dissociative Experiences Scale. Fifteen of these participants were evaluated thoroughly with the Structured Clinical Interview for DSM-IV Axis I, Structured Clinical Interview for DSM-IV Axis II, and Structured Clinical Interview for DSM-IV Dissociative Disorders to determine whether they met the criteria for dissociative schizophrenia and to generate a clinical description. Our results indicated that 24% of the individuals we tested met these criteria. We propose making mandatory 1 of the 3 dissociative symptoms of the criteria to eliminate people with only nonspecific symptoms (e.g., extensive comorbidity). According to this modified criterion, 14% of our sample would receive a diagnosis of dissociative schizophrenia. However, a more comprehensive look at the clinical picture begs the question of whether dissociative schizophrenia is truly present in every person meeting the criteria. We discuss the relevance of creating a new schizophrenia subtype and offer recommendations for clinicians.

Somatoform and psychoform dissociation among women with orgasmic and sexual pain disorders.

PubMed

Farina, Benedetto; Mazzotti, Eva; Pasquini, Paolo; Mantione, Maria Giuseppina

2011-01-01

Since the 20th century, psychogenic female sexual dysfunctions (FSD), like some somatoform and conversion disorders, have been considered an expression of somatoform dissociation. Several studies have reported dissociative symptoms in different somatoform and conversion disorders, but limited data are available on dissociation among patients with FSD. The aim of this study was to assess somatoform and psychoform dissociation among patients with women's orgasmic disorder, dyspareunia, and vaginismus. A battery of self-administered questionnaires (Somatoform Dissociation Questionnaire, Dissociative Experiences Scale, Hospital Anxiety and Depression Scale, Impact of Event Scale-Revised) was given to 200 gynecological outpatients to assess psychoform and somatoform dissociation and their association with FSD. A strong association between somatoform dissociation and FSD was observed (adjusted odds ratio [OR] = 5.39, 95% confidence interval [CI] = 1.15-25.32), the association between somatoform and psychoform dissociation being estimated by an adjusted OR of 4.83 (95% CI = 1.17-19.91). Our results are compatible with the idea that some forms of FSD could be regarded as somatoform dissociative disorders.

Validity and reliability of the Turkish version of the DSM-5 Dissociative Symptoms Severity Scale-Child Form.

PubMed

Yalın Sapmaz, Şermin; Ergin, Dilek; Şen Celasin, Nesrin; Özek Erkuran, Handan; Karaarslan, Duygu; Öztekin, Siğnem; Uzel Tanrıverdi, Bengisu; Köroğlu, Ertuğrul; Aydemir, Ömer

2017-01-01

The goal of this study was to assess the validity and reliability of the Turkish version of the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) Dissociative Symptoms Severity Scale-Child Form. The scale was prepared by translating and then back-translating the DSM-5 Dissociative Symptoms Severity Scale. The study groups included one group of 30 patients diagnosed with posttraumatic stress disorder who were treated in a child and adolescent psychiatry unit and another group of 83 healthy volunteers from middle and high schools in the community. For assessment, the Adolescent Dissociative Experiences Scale (ADES) was used in addition to the DSM-5 Dissociative Symptoms Severity Scale. Regarding the reliability of the DSM-5 Dissociative Symptoms Severity Scale, Cronbach's alpha was .824 and item-total score correlation coefficients were between .464 and .648. The test-retest correlation coefficient was calculated to be r = .784. In terms of construct validity, one factor accounted for 45.2% of the variance. Furthermore, in terms of concurrent validity, the scale showed a high correlation with the ADES. In conclusion, the Turkish version of the DSM-5 Dissociative Symptoms Severity Scale-Child Form is a valid and reliable tool for both clinical practice and research.

Dissociation in the laboratory: a comparison of strategies.

PubMed

Leonard, K N; Telch, M J; Harrington, P J

1999-01-01

Several methods for inducing dissociation in the laboratory were examined in a sample of 78 undergraduate students. Participants scoring high or low on the Dissociative Experiences Scale participated in three dissociation challenge conditions: (a) dot-staring task, (b) administration of pulsed photic and audio stimulation and (c) stimulus deprivation. Participants recorded their dissociative experiences both before and after each of the three challenge conditions. Across conditions, high DES participants reported significantly more dissociative sensations than low DES participants, even after controlling for pre-challenge dissociation. Moreover, regardless of DES status, pulsed photo and audio stimulation produced the greatest level of dissociative symptoms. The findings suggest that the induction of dissociative symptoms in a nonclinical sample is easily accomplished in the laboratory and that those who report more dissociative symptoms in their day-to-day life exhibit more pronounced dissociative symptoms when undergoing dissociative challenge in the laboratory. Implications for the study and treatment of dissociative symptoms are discussed.

Déjà vu experiences are rarely associated with pathological dissociation.

PubMed

Adachi, Naoto; Akanuma, Nozomi; Akanu, Nozomi; Adachi, Takuya; Takekawa, Yoshikazu; Adachi, Yasushi; Ito, Masumi; Ikeda, Hiroshi

2008-05-01

We investigated the relation between déjà vu and dissociative experiences in nonclinical subjects. In 227 adult volunteers, déjà vu and dissociative experiences were evaluated by means of the inventory of déjà vu experiences assessment and dissociative experiences scale (DES). Déjà vu experiences occurred in 162 (71.4%) individuals. In univariate correlation analysis, the frequency of déjà vu experiences, as well as 5 other inventory of déjà vu experiences assessment symptoms and age at the time of evaluation, correlated significantly with the DES score. After exclusion of intercorrelative effects using multiple regression analysis, déjà vu experiences did not remain in the model. The DES score was best correlated with a model that included age, jamais vu, depersonalization, and precognitive dreams. Two indices for pathological dissociation (DES-taxon and DES > or = 30) were not associated with déjà vu experiences. Our findings suggest that déjà vu experiences are unlikely to be core pathological dissociative experiences.

Three dimensions of dissociative amnesia.

PubMed

Dell, Paul F

2013-01-01

Principal axis factor analysis with promax rotation extracted 3 factors from the 42 memory and amnesia items of the Multidimensional Inventory of Dissociation (MID) database (N = 2,569): Discovering Dissociated Actions, Lapses of Recent Memory and Skills, and Gaps in Remote Memory. The 3 factors' shared variance ranged from 36% to 64%. Construed as scales, the 3 factor scales had Cronbach's alpha coefficients of .96, .94, and .93, respectively. The scales correlated strongly with mean Dissociative Experiences Scale scores, mean MID scores, and total scores on the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised (SCID-D-R). What is interesting is that the 3 amnesia factors exhibited a range of correlations with SCID-D-R Amnesia scores (.52, .63, and .70, respectively), suggesting that the SCID-D-R Amnesia score emphasizes gaps in remote memory over amnesias related to dissociative identity disorder. The 3 amnesia factor scales exhibited a clinically meaningful pattern of significant differences among dissociative identity disorder, dissociative disorder not otherwise specified-1, dissociative amnesia, depersonalization disorder, and nonclinical participants. The 3 amnesia factors may have greater clinical utility for frontline clinicians than (a) amnesia as discussed in the context of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, nosology of the dissociative disorders or (b) P. Janet's (1893/1977 ) 4-fold classification of dissociative amnesia. The author recommends systematic study of the phenomenological differences within specific dissociative symptoms and their differential relationship to specific dissociative disorders.

"I Feel Like I do Not Exist:" A Study of Dissociative Experiences Among War-Traumatized Refugee Youth.

PubMed

Gušić, Sabina; Malešević, Andrea; Cardeña, Etzel; Bengtsson, Hans; Søndergaard, Hans Peter

2017-11-20

War-traumatized refugee children and adolescents have been overlooked in research on trauma-related dissociation, and whatever research has been conducted has relied almost exclusively on questionnaires. The present study was an exploration of dissociative experiences in multitraumatized war-refugee youth. In this study, we used a mixed-method approach by grouping participants according to a Western-based dissociation measure (the Adolescent Dissociative Experiences Scale; Armstrong, Putnam, Carlson, Libero, & Smith, 1997), and conducting qualitative and quantitative analyses of their verbal descriptions of mental experiences related to dissociation in the aftermath of war and resettlement. The sample included 40 refugee youth, ages 13 to 21, 19 girls and 21 boys resettled in Sweden because of war and persecution. Severe trauma-related dissociation was a problem for a considerable subgroup of the sample. Some dissociative experiences were present in all the sample; others were restricted to the most dissociative group. The correlates of severe dissociation included high frequency and severity of emotional dysregulation and intensity, negative self- and body-perception, depressive mood, and experiences of detachment. Clinicians are urged to be aware of and assess trauma-related dissociation in war-refugee youth, and consider not only dissociative phenomena, but also other important processes such as emotional dysregulation. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Personality assessment inventory profile and predictors of elevations among dissociative disorder patients.

PubMed

Stadnik, Ryan D; Brand, Bethany; Savoca, Angela

2013-01-01

Assessing patients with dissociative disorders (DD) using personality tests is difficult. On the Minnesota Multiphasic Personality Inventory-2 ( J. N. Butcher, W. G. Dahlstrom, J. R. Graham, A. Tellegen, & B. Kaemmer, 1989 ), DD patients often obtain elevations on multiple clinical scales as well as on validity scales that were thought to indicate exaggeration yet have been shown to be elevated among traumatized individuals, including those with DD. No research has been conducted to determine how DD patients score on the Personality Assessment Inventory (PAI; L. C. Morey, 1991 ), which includes the symptom exaggeration scale Negative Impression (NIM) and the malingering scales Malingering Index (MAL) and Rogers Discriminant Function (RDF). The goals of this study were to document the PAI profile of dissociative identity disorder (DID) and dissociative disorder not otherwise specified (DDNOS) patients and to determine how the validity and Schizophrenia scales are related to other PAI scales as well as dissociation. A total of 42 inpatients with DID or DDNOS were assessed on the PAI as well as the Dissociative Experiences Scale-II. The DID/DDNOS patients were elevated on many PAI scales, including NIM and, to a lesser extent, MAL, but not RDF. Dissociation scores significantly and uniquely predicted NIM scores above and beyond Depression and Borderline Features. In addition, after we controlled for MAL and RDF, dissociation was positively associated with NIM. In contrast, after we controlled for the other 2 scales, dissociation was not related to MAL and was negatively related to RDF, indicating that RDF and, to a lesser extent, MAL are better correlates of feigning in DD patients than NIM.

Brain functional integration: an epidemiologic study on stress-producing dissociative phenomena.

PubMed

Sperandeo, Raffaele; Monda, Vincenzo; Messina, Giovanni; Carotenuto, Marco; Maldonato, Nelson Mauro; Moretto, Enrico; Leone, Elena; De Luca, Vincenzo; Monda, Marcellino; Messina, Antonietta

2018-01-01

Dissociative phenomena are common among psychiatric patients; the presence of these symptoms can worsen the prognosis, increasing the severity of their clinical conditions and exposing them to increased risk of suicidal behavior. Personality disorders as long duration stressful experiences may support the development of dissociative phenomena. In 933 psychiatric outpatients consecutively recruited, presence of dissociative phenomena was identified with the Dissociative Experience Scale (DES). Dissociative phenomena were significantly more severe in the group of people with mental disorders and/or personality disorders. All psychopathologic traits detected with the symptom checklist-90-revised had a significant correlation with the total score on the DES. Using total DES score as the dependent variable, a linear regression model was constructed. Mental and personality disorders which were associated with greater severity of dissociative phenomena on analysis of variance were included as predictors; scores from the nine scales of symptom checklist-90-revised, significantly correlated to total DES score, were used as covariates. The model consisted of seven explanatory variables (four factors and three covariates) explaining 82% of variance. The four significant factors were the presence of borderline and narcissistic personality disorder, substance abuse disorders and psychotic disorders. Significant covariates were psychopathologic traits of anger, psychoticism and obsessiveness. This study, confirming Janet's theory, explains that, mental disorders and psychopathologic experiences of patients can configure the chronic stress condition that produces functional damage to the adaptive executive system. The symptoms of dissociative depersonalization/derealization and dissociative amnesia can be explained, in large part, through their current and previous psychopathologic experiences.

Brain functional integration: an epidemiologic study on stress-producing dissociative phenomena

PubMed Central

Messina, Giovanni; Carotenuto, Marco; Maldonato, Nelson Mauro; Moretto, Enrico; Leone, Elena; De Luca, Vincenzo; Monda, Marcellino; Messina, Antonietta

2018-01-01

Dissociative phenomena are common among psychiatric patients; the presence of these symptoms can worsen the prognosis, increasing the severity of their clinical conditions and exposing them to increased risk of suicidal behavior. Personality disorders as long duration stressful experiences may support the development of dissociative phenomena. In 933 psychiatric outpatients consecutively recruited, presence of dissociative phenomena was identified with the Dissociative Experience Scale (DES). Dissociative phenomena were significantly more severe in the group of people with mental disorders and/or personality disorders. All psychopathologic traits detected with the symptom checklist-90-revised had a significant correlation with the total score on the DES. Using total DES score as the dependent variable, a linear regression model was constructed. Mental and personality disorders which were associated with greater severity of dissociative phenomena on analysis of variance were included as predictors; scores from the nine scales of symptom checklist-90-revised, significantly correlated to total DES score, were used as covariates. The model consisted of seven explanatory variables (four factors and three covariates) explaining 82% of variance. The four significant factors were the presence of borderline and narcissistic personality disorder, substance abuse disorders and psychotic disorders. Significant covariates were psychopathologic traits of anger, psychoticism and obsessiveness. This study, confirming Janet’s theory, explains that, mental disorders and psychopathologic experiences of patients can configure the chronic stress condition that produces functional damage to the adaptive executive system. The symptoms of dissociative depersonalization/derealization and dissociative amnesia can be explained, in large part, through their current and previous psychopathologic experiences. PMID:29296086

Frontal and occipital perfusion changes in dissociative identity disorder.

PubMed

Sar, Vedat; Unal, Seher N; Ozturk, Erdinc

2007-12-15

The aim of the study was to investigate if there were any characteristics of regional cerebral blood flow (rCBF) in dissociative identity disorder. Twenty-one drug-free patients with dissociative identity disorder and nine healthy volunteers participated in the study. In addition to a clinical evaluation, dissociative psychopathology was assessed using the Structured Clinical Interview for DSM-IV Dissociative Disorders, the Dissociative Experiences Scale and the Clinician-Administered Dissociative States Scale. A semi-structured interview for borderline personality disorder, the Hamilton Depression Rating Scale, and the Childhood Trauma Questionnaire were also administered to all patients. Normal controls had to be without a history of childhood trauma and without any depressive or dissociative disorder. Regional cerebral blood flow (rCBF) was studied with single photon emission computed tomography (SPECT) with Tc99m-hexamethylpropylenamine (HMPAO) as a tracer. Compared with findings in the control group, the rCBF ratio was decreased among patients with dissociative identity disorder in the orbitofrontal region bilaterally. It was increased in median and superior frontal regions and occipital regions bilaterally. There was no significant correlation between rCBF ratios of the regions of interest and any of the psychopathology scale scores. An explanation for the neurophysiology of dissociative psychopathology has to invoke a comprehensive model of interaction between anterior and posterior brain regions.

The relationship of problematic internet use with dissociation among South Korean internet users.

PubMed

Lee, Tae Kyung; Roh, Sungwon; Han, Joo Hyun; Park, Se Jin; Soh, Min A; Han, Doug Hyun; Shaffer, Howard J

2016-07-30

This study examined patterns of problematic internet use (PIU) among South Korean internet users to investigate the association between PIU and dissociative experiences. Five hundred and eight participants between 20 and 49 years old were recruited through an online panel survey. Using logistic regression analysis with PIU as the dependent variable, we observed that the participants with PIU were more likely to have alcohol-related behaviors or problems, higher levels of perceived stress, and dissociative experiences. Participants' scores on the Korean version of the Dissociative Experiences Scale were positively correlated with the severity of PIU. Individuals with PIU and dissociation had more severe PIU and more severe mental-health problems than those with PIU but without dissociation. These findings suggest that treatment programs for persons with PIU should focus on helping them tolerate negative affect and increase their level of awareness to prevent the occurrence of dissociative experiences. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Development and Preliminary Psychometric Properties of an Instrument for the Measurement of Obsessional Dissociative Experiences: The Van Obsessional Dissociation Questionnaire (VOD-Q).

PubMed

Boysan, Murat; Yıldırım, Abdullah; Beşiroğlu, Lütfullah; Kefeli, Mehmet Celal; Kağan, Mücahit

2018-01-04

A growing body of research evidence documents the substantial associations between obsessive-compulsive disorder (OCD) and dissociation. This article describes the development and preliminary psychometric properties of the Van Obsessional Dissociation Questionnaire (VOD-Q). Obsessional dissociation is defined as a tendency to dissociate in reaction to distressing, unwanted and intrusive thoughts, images and impulses. The screening tool is conceptualized to tap obsessional dissociation across three dimensions: obsessional absorption, obsessional depersonalization/ derealization and obsessional amnesia. The VOD-Q, the Padua Inventory-Revised (PI-R), the Dissociative Experiences Scale (DES), and the Obsessive Belief Questionnaire (OBQ-44) were administered in this study. The results showed that the VOD-Q had excellent test-retest reliability (ranging from 0.73 to 0.90) and internal consistency (ranging from 0.90 to 0.97). The VOD-Q total and subscale scores were significantly associated with measures of obsessive-compulsive symptoms and dissociative experiences. OCD patients scored significantly higher on the VOD-Q than community participants. Based on the present findings, the VOD-Q appears to be a reliable and valid instrument for the measurement of obsessional dissociative experiences.

Suggestibility and signal detection performance in hallucination-prone students.

PubMed

Alganami, Fatimah; Varese, Filippo; Wagstaff, Graham F; Bentall, Richard P

2017-03-01

Auditory hallucinations are associated with signal detection biases. We examine the extent to which suggestions influence performance on a signal detection task (SDT) in highly hallucination-prone and low hallucination-prone students. We also explore the relationship between trait suggestibility, dissociation and hallucination proneness. In two experiments, students completed on-line measures of hallucination proneness (the revised Launay-Slade Hallucination Scale; LSHS-R), trait suggestibility (Inventory of Suggestibility) and dissociation (Dissociative Experiences Scale-II). Students in the upper and lower tertiles of the LSHS-R performed an auditory SDT. Prior to the task, suggestions were made pertaining to the number of expected targets (Experiment 1, N = 60: high vs. low suggestions; Experiment 2, N = 62, no suggestion vs. high suggestion vs. no voice suggestion). Correlational and regression analyses indicated that trait suggestibility and dissociation predicted hallucination proneness. Highly hallucination-prone students showed a higher SDT bias in both studies. In Experiment 1, both bias scores were significantly affected by suggestions to the same degree. In Experiment 2, highly hallucination-prone students were more reactive to the high suggestion condition than the controls. Suggestions may affect source-monitoring judgments, and this effect may be greater in those who have a predisposition towards hallucinatory experiences.

Dissociation and psychosis in dissociative identity disorder and schizophrenia.

PubMed

Laddis, Andreas; Dell, Paul F

2012-01-01

Dissociative symptoms, first-rank symptoms of schizophrenia, and delusions were assessed in 40 schizophrenia patients and 40 dissociative identity disorder (DID) patients with the Multidimensional Inventory of Dissociation (MID). Schizophrenia patients were diagnosed with the Structured Clinical Interview for the DSM-IV Axis I Disorders; DID patients were diagnosed with the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised. DID patients obtained significantly (a) higher dissociation scores; (b) higher passive-influence scores (first-rank symptoms); and (c) higher scores on scales that measure child voices, angry voices, persecutory voices, voices arguing, and voices commenting. Schizophrenia patients obtained significantly higher delusion scores than did DID patients. What is odd is that the dissociation scores of schizophrenia patients were unrelated to their reports of childhood maltreatment. Multiple regression analyses indicated that 81% of the variance in DID patients' dissociation scores was predicted by the MID's Ego-Alien Experiences Scale, whereas 92% of the variance in schizophrenia patients' dissociation scores was predicted by the MID's Voices Scale. We propose that schizophrenia patients' responses to the MID do not index the same pathology as do the responses of DID patients. We argue that neither phenomenological definitions of dissociation nor the current generation of dissociation instruments (which are uniformly phenomenological in nature) can distinguish between the dissociative phenomena of DID and what we suspect are just the dissociation-like phenomena of schizophrenia.

Predictors of Risk and Resilience for Posttraumatic Stress Disorder Among Ground Combat Marines: Methods of the Marine Resiliency Study

DTIC Science & Technology

2012-01-01

were modified slightly for use in the study, including linking the widely used PTSD Checklist, Peritraumatic Dissociative Experiences Questionnaire...duration of unconsciousness, and altered mental state (AMS) (eg, confusion or dazed feeling or posttraumatic amnesia ). To ensure interrater...X X Dissociative Experiences Scale (DES) X — — X Janoff-Bulman World Assumptions Scale (WAS) X X X — Psychiatric symptoms PTSD Checklist (PCL) X X X X

Dissociation in patients with schizophrenia spectrum disorders: What is the role of different types of childhood adversity?

PubMed

Schroeder, Katrin; Langeland, Willemien; Fisher, Helen L; Huber, Christian G; Schäfer, Ingo

2016-07-01

Our study aimed to explore the effects of different types of adverse childhood experiences (e.g. domestic violence, early loss, parental dysfunction, sexual and physical abuse) as well as experiences of sexual and physical abuse in adulthood on dissociative symptoms in adult patients with schizophrenia-spectrum disorders. 145 patients were examined for psychotic symptoms with the Positive and Negative Syndrome Scale (PANSS), for dissociative symptoms with the German version of the Dissociative Experiences Scale (DES) and for adverse experiences in childhood and adulthood with the Structured Trauma Interview (STI). Childhood physical abuse was reported by 32%, childhood sexual abuse by 17% of the patients. Other forms of childhood adversity were also quite common; 18% had witnessed domestic violence, 26% reported early loss, and nearly half of patients reported at least one condition potentially related to parental dysfunction. The DES total score was significantly associated with childhood sexual abuse, witnessing of domestic violence and paternal dysfunction, as well as with physical violence in adulthood. In the final regression model, reports of paternal dysfunction and sexual abuse in childhood were independently associated with adult dissociation. Variance in dissociative symptoms was mainly explained by paternal dysfunction (18%). Substantial rates of childhood adversity were found and specific associations were evident with adult dissociation amongst psychosis patients who reported sexual abuse or paternal dysfunction in childhood. Therefore, it is important that patients with schizophrenia-spectrum disorders are routinely asked about a broad range of possible adverse childhood experiences in order to provide appropriate interventions. Copyright © 2016 Elsevier Inc. All rights reserved.

Psychometric properties of the Adolescent Dissociative Experiences Scale in a sample of Italian adolescents.

PubMed

Schimmenti, Adriano

2016-01-01

The purpose of this study was to examine the psychometric properties of the Italian translation of the Adolescent Dissociative Experiences Scale (A-DES). A sample of 1,806 high-school students between the ages of 13 and 18 years, recruited in 6 Italian cities, completed the A-DES. The A-DES showed high internal consistency, excellent item-to-scale homogeneity, good split-half reliability, and a single-factor structure. The scores of the Italian adolescents were comparable to those found in previous research with the measure. No gender differences were found in mean A-DES scores, but boys and girls showed different patterns of responses on A-DES items. Age differences were also found, with 13- and 18-year-old students scoring higher on the measure than the other participants. A cluster analysis showed that participants could be consistently grouped into 2 clusters of low- and high-dissociative adolescents. This study supports the A-DES as a reliable and valid screening measure for dissociative symptoms in adolescents.

Correlates of the multidimensional construct of hypnotizability: paranormal belief, fantasy proneness, magical ideation, and dissociation.

PubMed

Dasse, Michelle N; Elkins, Gary R; Weaver, Charles A

2015-01-01

Hypnotizability is a multifaceted construct that may relate to multiple aspects of personality and beliefs. This study sought to address 4 known correlates of hypnotizability to aid in its understanding. Eighty undergraduates completed the Magical Ideation Scale (MIS), the Creative Experiences Questionnaire (CEQ), the Australian Sheep-Goat Scale (ASGS), and the Dissociative Experiences Scale (DES) and then were administered the Creative Imagination Scale (CIS). All 5 scales were significantly correlated. Participants higher in hypnotizability scored higher on the CEQ and the MIS. The findings demonstrate the influence of fantasy proneness and magical thinking on hypnotizability and support the theory that hypnotizability is a complex interaction of multiple traits.

Dissociation and symptoms of culture-bound syndromes in North America: a preliminary study.

PubMed

Ross, Colin A; Schroeder, Elizabeth; Ness, Laura

2013-01-01

The aim of this study was to determine whether classical culture-bound syndromes occur among psychiatric inpatients with dissociative disorders in North America. The Dissociative Trance Disorder Interview Schedule, the Dissociative Experiences Scale, and the Dissociative Disorders Interview Schedule were administered to 100 predominantly Caucasian, American, English-speaking trauma program inpatients at a hospital in the United States. The participants reported high rates of childhood physical and/or sexual abuse (87%), dissociative disorders (73%), and membership in the dissociative taxon (78%). They also reported a wide range of possession experiences and exorcism rituals, as well as the classical culture-bound syndromes of latah, bebainan, amok, and pibloktoq. Our data are consistent with the view that possession and classical culture-bound syndromes are predominantly dissociative in nature and not really culture-bound from the perspective of Caucasian, English-speaking America.

Dissociative symptoms and dissociative disorders comorbidity in obsessive compulsive disorder: Symptom screening, diagnostic tools and reflections on treatment

PubMed Central

Belli, Hasan

2014-01-01

Borderline personality disorder, conversion disorder and obsessive compulsive disorder frequently have dissociative symptoms. The literature has demonstrated that the level of dissociation might be correlated with the severity of obsessive compulsive disorder (OCD) and that those not responding to treatment had high dissociative symptoms. The structured clinical interview for DSM-IV dissociative disorders, dissociation questionnaire, somatoform dissociation questionnaire and dissociative experiences scale can be used for screening dissociative symptoms and detecting dissociative disorders in patients with OCD. However, a history of neglect and abuse during childhood is linked to a risk factor in the pathogenesis of dissociative psychopathology in adults. The childhood trauma questionnaire-53 and childhood trauma questionnaire-40 can be used for this purpose. Clinicians should not fail to notice the hidden dissociative symptoms and childhood traumatic experiences in OCD cases with severe symptoms that are resistant to treatment. Symptom screening and diagnostic tools used for this purpose should be known. Knowing how to treat these pathologies in patients who are diagnosed with OCD can be crucial. PMID:25133142

Dissociative symptoms and dissociative disorders comorbidity in obsessive compulsive disorder: Symptom screening, diagnostic tools and reflections on treatment.

PubMed

Belli, Hasan

2014-08-16

Borderline personality disorder, conversion disorder and obsessive compulsive disorder frequently have dissociative symptoms. The literature has demonstrated that the level of dissociation might be correlated with the severity of obsessive compulsive disorder (OCD) and that those not responding to treatment had high dissociative symptoms. The structured clinical interview for DSM-IV dissociative disorders, dissociation questionnaire, somatoform dissociation questionnaire and dissociative experiences scale can be used for screening dissociative symptoms and detecting dissociative disorders in patients with OCD. However, a history of neglect and abuse during childhood is linked to a risk factor in the pathogenesis of dissociative psychopathology in adults. The childhood trauma questionnaire-53 and childhood trauma questionnaire-40 can be used for this purpose. Clinicians should not fail to notice the hidden dissociative symptoms and childhood traumatic experiences in OCD cases with severe symptoms that are resistant to treatment. Symptom screening and diagnostic tools used for this purpose should be known. Knowing how to treat these pathologies in patients who are diagnosed with OCD can be crucial.

Identifying dissociative identity disorder: a self-report and projective study.

PubMed

Scroppo, J C; Drob, S L; Weinberger, J L; Eagle, P

1998-05-01

This study compared 21 female adult psychiatric patients diagnosed with dissociative identity disorder (DID) with 21 female adult nondissociative psychiatric patients to determine whether DID patients exhibit a distinguishing set of clinical features, and perceptual, attentional, and cognitive processes. Participants were assessed with the Dissociative Disorders Interview Schedule to assess diagnostic status. Group scores on the Dissociative Experiences Scale, Tellegen Absorption Scale, Childhood Trauma Questionnaire, Brief Symptom Inventory, and the Rorschach test were compared. DID participants reported earlier and more severe childhood trauma, more dissociative symptoms, and a greater propensity for altered states of consciousness. The DID participants also exhibited increased projective and imaginative activity, a diminished ability to integrate mental contents, a complex and driven cognitive style, and a highly unconventional view of reality.

The Shutdown Dissociation Scale (Shut-D)

PubMed Central

Schalinski, Inga; Schauer, Maggie; Elbert, Thomas

2015-01-01

The evolutionary model of the defense cascade by Schauer and Elbert (2010) provides a theoretical frame for a short interview to assess problems underlying and leading to the dissociative subtype of posttraumatic stress disorder. Based on known characteristics of the defense stages “fright,” “flag,” and “faint,” we designed a structured interview to assess the vulnerability for the respective types of dissociation. Most of the scales that assess dissociative phenomena are designed as self-report questionnaires. Their items are usually selected based on more heuristic considerations rather than a theoretical model and thus include anything from minor dissociative experiences to major pathological dissociation. The shutdown dissociation scale (Shut-D) was applied in several studies in patients with a history of multiple traumatic events and different disorders that have been shown previously to be prone to symptoms of dissociation. The goal of the present investigation was to obtain psychometric characteristics of the Shut-D (including factor structure, internal consistency, retest reliability, predictive, convergent and criterion-related concurrent validity). A total population of 225 patients and 68 healthy controls were accessed. Shut-D appears to have sufficient internal reliability, excellent retest reliability, high convergent validity, and satisfactory predictive validity, while the summed score of the scale reliably separates patients with exposure to trauma (in different diagnostic groups) from healthy controls. The Shut-D is a brief structured interview for assessing the vulnerability to dissociate as a consequence of exposure to traumatic stressors. The scale demonstrates high-quality psychometric properties and may be useful for researchers and clinicians in assessing shutdown dissociation as well as in predicting the risk of dissociative responding. PMID:25976478

Multiple personality disorder among female inpatients in a state hospital.

PubMed

Latz, T T; Kramer, S I; Hughes, D L

1995-09-01

Professional skepticism and concerns regarding diagnostic reliability hinder research in dissociative disorders and multiple personality disorder. The reported frequency of multiple personality disorder in different psychiatric settings ranges from 2.4% to 35%. The authors conducted a replication study of multiple personality disorder ascertainment in women admitted to a state hospital over a 5.5-month period. Responses to the Dissociative Experiences Scale and to the Dissociative Disorders Interview Schedule were obtained, along with data on length of stay, county of admission referral, admission commitment status, and discharge diagnoses, for 176 female inpatients in a state hospital. Of 421 women representing 483 consecutive admissions, 121 were discharged before they could be assessed for study, 64 were excluded, 60 declined to participate, 176 enrolled in the study, and 175 completed the research procedures. Twenty-one women (12%) met criteria for multiple personality disorder based on the Dissociative Disorders Interview Schedule; these women were significantly younger than the women without multiple personality disorder. Scores on the Dissociative Experiences Scale of the women with multiple personality disorder (mean = 59.5, SD = 19.6) were significantly higher than the scores of women without multiple personality disorder (mean = 22.5, SD = 20.1), but considerable overlap occurred. There was no significant difference between groups in length of stay or admission status. The authors conclude that 1) the wide variability in multiple personality disorder detection is partially due to site-specific ascertainment biases and 2) despite its apparent usefulness for screening purposes, the Dissociative Experiences Scale requires more comprehensive evaluation before it can be applied broadly.

Hypnotic suggestibility, cognitive inhibition, and dissociation.

PubMed

Dienes, Zoltán; Brown, Elizabeth; Hutton, Sam; Kirsch, Irving; Mazzoni, Giuliana; Wright, Daniel B

2009-12-01

We examined two potential correlates of hypnotic suggestibility: dissociation and cognitive inhibition. Dissociation is the foundation of two of the major theories of hypnosis and other theories commonly postulate that hypnotic responding is a result of attentional abilities (including inhibition). Participants were administered the Waterloo-Stanford Group Scale of Hypnotic Susceptibility, Form C. Under the guise of an unrelated study, 180 of these participants also completed: a version of the Dissociative Experiences Scale that is normally distributed in non-clinical populations; a latent inhibition task, a spatial negative priming task, and a memory task designed to measure negative priming. The data ruled out even moderate correlations between hypnotic suggestibility and all the measures of dissociation and cognitive inhibition overall, though they also indicated gender differences. The results are a challenge for existing theories of hypnosis.

People reporting experiences of mediumship have higher dissociation symptom scores than non-mediums, but below thresholds for pathological dissociation

PubMed Central

Wahbeh, Helané; Radin, Dean

2018-01-01

Background: Dissociative states exist on a continuum from nonpathological forms, such as highway hypnosis and day-dreaming, to pathological states of derealization and depersonalization. Claims of communication with deceased individuals, known as mediumship, were once regarded as a pathological form of dissociation, but current definitions recognize the continuum and include distress and functional disability as symptoms of pathology. This study examined the relationship between dissociative symptoms and mediumship in a large convenience sample. Methods: Secondary analyses of cross-sectional survey data were conducted. The survey included demographics, the Dissociation Experience Scale Taxon (DES-T, score range 0-100), as well as questions about instances of mediumship experiences. Summary statistics and linear and logistic regressions explored the relationship between dissociative symptoms and mediumship endorsement. Results: 3,023 participants were included and were mostly middle-aged (51 years ± 16; range 17-96), female (70%), Caucasian (85%), college educated (88%), had an annual income over $50,000 (55%), and were raised Christian (71%) but were presently described as Spiritual but not Religious (60%). Mediumship experiences were endorsed by 42% of participants, the experiences usually began in childhood (81%), and 53% had family members who reported similar experiences. The mean DES-T score across all participants was 14.4 ± 17.3, with a mean of 18.2 ± 19.3 for those claiming mediumship experiences and 11.8 ± 15.2 for those who did not (t = -10.3, p < 0.0005). The DES-T threshold score for pathological dissociation is 30. Conclusions: On average, individuals claiming mediumship experiences had higher dissociation scores than non-claimants, but neither group exceeded the DES-T threshold for pathology. Future studies exploring dissociative differences between these groups may benefit from using more comprehensive measures of dissociative symptoms as well as assessments of functional impairment, which would help in discerning between pathological and non-pathological aspects of these experiences. PMID:29416850

Dissociative symptoms in female patients with mood and anxiety disorders: a psychopathological and temperamental investigation.

PubMed

Bersani, G; Moscariello, M A; Bersani, F S; Colletti, C; Anastasia, A; Prinzivalli, E; Valeriani, G; Salviati, M

2014-01-01

Dissociative symptoms are frequent among psychiatric patients and may considerably affect patients' psychopathological condition and treatment outcomes. The objectives of the study are to assess the presence of dissociative symptoms in female patients with mood and anxiety disorders, to investigate their correlation with the clinical severity of the disorders and to investigate those personality traits that are more frequent in patients with high levels of dissociation. 50 Caucasian females were enrolled in the study. Patients were assessed through the Self-Report Symptom Check-List, the Dissociative Experiences Scale (DES) and rating scales for Depression and Anxiety. The mean DES score in the overall sample was 16.6. 32% of patients had a DES score > 20. Depressive symptoms positively correlated with the DES total scores. Dissociator patients presented some significantly different temperamental characteristics in comparison with non dissociator patients. Dissociative symptoms are highly present in patients with mood and anxiety disorders and correlate with the severity of depressive symptoms. Specific personality traits more frequently observed in dissociator people may represent predisposing factors; their early identification could be clinically relevant.

Childhood emotional abuse, dissociation, and suicidality among patients with drug dependency in Turkey.

PubMed

Tamar-Gurol, Defne; Sar, Vedat; Karadag, Figen; Evren, Cuneyt; Karagoz, Mustafa

2008-10-01

The aim of the present study was to determine the prevalence and correlates of dissociative disorders among patients with drug dependency. The Dissociative Experiences Scale (DES) was used to screen 104 consecutive patients at an addiction treatment center. Thirty-seven patients who had scores >or=30 were compared with 21 patients who scored <10 on the DES. Both groups were then evaluated using the Dissociative Disorders Interview Schedule and the Structured Clinical Interview for Dissociative Disorders (SCID-D). The interviewers were blind to the DES scores. Twenty-seven patients (26.0%) had a dissociative disorder according to the SCID-D. Dissociative patients were younger than the non-dissociative group. History of suicide attempt and/or childhood emotional abuse was significant predictors of a dissociative disorder. The majority (59.3%) of dissociative drug users reported that dissociative experiences had existed prior to substance use. More patients in the dissociative disorder than in the non-dissociative group stopped their treatment prematurely. A considerable proportion of drug users have a dissociative disorder, which may also interfere with treatment process. The relatively young age of this subgroup of patients and frequent reports of childhood emotional abuse underline potential preventive benefits of early intervention among adolescents with developmental trauma history and dissociative psychopathology.

Relations between Post-traumatic Stress Disorder, Dissociation and Attention-Deficit/Hyperactivity Disorder among Earthquake Survivors

PubMed Central

ÖZDEMİR, Osman; BOYSAN, Murat; GÜZEL ÖZDEMİR, Pınar; YILMAZ, Ekrem

2015-01-01

Introduction There is a burgeoning interest in relations between post-traumatic stress disorder (PTSD) and attention-deficit/hyperactivity disorder (ADHD). Although few studies were conducted, weak evidence was found supporting the hypothesis that ADHD may be a risk factor for the development of PTSD. In addition, there is a paucity of research addressing the relations between dissociation and ADHD. In this study, our aim was to examine the relations between PTSD and ADHD combined with the mediating effect of dissociative psychopathology. Methods The participants were 317 undergraduate students, a greater proportion of whom experienced the 2011 Van earthquake (66%). The participants were administered the Posttraumatic Diagnostic Scale, Dissociative Experiences Scale, Adult ADHD Self-Report Scale, Beck Depression Inventory and Beck Anxiety Inventory. Results We found that ADHD symptoms and dissociation were significantly associated with PTSD. Considering the multivariate relations between ADHD, PTSD and dissociation, significant associations between PTSD and ADHD resulted from symptom overlaps. However, pathological dissociation mediated the relations between PTSD and ADHD. Conclusion We concluded that ADHD comorbidity was not a predominant vulnerability factor for the development of post-traumatic stress response but may be an exacerbating factor after the development of PTSD. PMID:28360719

Cumulative trauma, PTSD and dissociation among Ethiopian refugees in Israel.

PubMed

Finklestein, Michal; Solomon, Zahava

2009-01-01

The aim of this study was to examine the exposure of Ethiopian refugees to pre-, peri- and post-migration stressful events and their implications for both posttraumatic stress disorder (PTSD) and dissociation. A random sample (N = 478) of three groups of refugees took part in the research ("Moses" immigrants, 1984, n = 165; "Solomon" immigrants, 1991, n = 169; "Family Reunification" immigrants, 1995, n = 144). Exposure to stressful events and posttraumatic symptoms were assessed via the Harvard Trauma Questionnaire (HTQ). Post-migration difficulties were assessed via the Post Migration Living Difficulties (PMLD) scale. Dissociation was evaluated using the Dissociation Experience Scale (DES). Significant differences were found among the groups in the rates of PTSD (27%, 15%, and 26%, respectively), but no differences were found in dissociation. A significant relationship was found between PTSD symptoms and cumulative trauma among the three groups, but no such relationship was found between dissociation and cumulative trauma. The differences among the groups were discussed in light of the unique characteristics of cumulative trauma, PTSD and dissociation among Ethiopian refugees.

Somatization as a predictor of suicidal ideation in dissociative disorders.

PubMed

Oztürk, Erdinç; Sar, Vedat

2008-12-01

This study was concerned with correlates of suicidal ideation among patients with chronic complex dissociative disorders. Participants were 40 patients diagnosed as having either dissociative identity disorder or dissociative disorder not otherwise specified according to the DSM-IV. The Dissociative Disorders Interview Schedule, the Dissociative Experiences Scale, the Somatoform Dissociation and the Childhood Trauma Questionnaires, the Spielberger Trait Anger Inventory, the Beck Suicidal Ideation Scale, and the Borderline Personality Disorder section of the Structured Clinical Interview for DSM-IV Personality Disorders were administered to all patients. Patients with suicidal ideas (n = 15) had concurrent somatization disorder more frequently than the remaining patients. Having significantly high scores on both trait and state dissociation measures, their dissociative disorder was more severe than that of the patients with no suicidal ideation. They had elevated scores for childhood emotional abuse, physical abuse and emotional neglect. Concurrent somatization disorder diagnosis was the only predictor of suicidal ideation when childhood trauma scores and borderline personality disorder diagnosis were controlled. Among dissociative patients, there is an association between somatization and suicidal ideation. A trauma-related insecure attachment pattern is considered as a common basis of this symptom cluster.

Assessment of complex dissociative disorder patients and simulated dissociation in forensic contexts.

PubMed

Brand, Bethany L; Webermann, Aliya R; Frankel, A Steven

Few assessors receive training in assessing dissociation and complex dissociative disorders (DDs). Potential differential diagnoses include anxiety, mood, psychotic, substance use, and personality disorders, as well as exaggeration and malingering. Individuals with DDs typically elevate on many clinical and validity scales on psychological tests, yet research indicates that they can be distinguished from DD simulators. Becoming informed about the testing profiles of DD individuals and DD simulators can improve the accuracy of differential diagnoses in forensic settings. In this paper, we first review the testing profiles of individuals with complex DDs and contrast them with DD simulators on assessment measures used in forensic contexts, including the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), Personality Assessment Inventory (PAI), and the Structured Inventory of Reported Symptoms (SIRS), as well as dissociation-specific measures such as the Dissociative Experiences Scale (DES) and Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D-R). We then provide recommendations for assessing complex trauma and dissociation through the aforementioned assessments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Psychotherapeutic treatment of eating disorders improve dissociative experiences and impulse regulation but not alexithymia. A case series report.

PubMed

Caslini, Manuela; Rivolta, Laura; Zappa, Luigi Enrico; Carrà, Giuseppe; Clerici, Massimo

2015-01-01

Eating disorders (EDs) are complex conditions associated with disability and a high rate of mortality. Typical characteristics of these diseases are dissociation, alexithymia and impulse dysregulation, all strategies dealing with negative emotions and regulate negative affect and anxiety. Our study aimed to assess the effectiveness of intensive psychological treatment for EDs, with particular reference to the above mentioned clinical characteristics. Eight outpatients with eating disorders in psychotherapeutic treatment were evaluated in two stages after one year (T1 and T2), using the Eating Disorder Inventory II, the Toronto Alexithymia Scale 20, and the Dissociative Experiences Scale. Wilcoxon test showed significant reductions in DES score as well as in two subscales of the EDI-2, Impulse Regulation and Body Dissatisfaction (I-EDI2 and BD-EDI2), while alexithymia levels did not show any difference. We can confirm the effectiveness of psychotherapy in people with EDs as regards dissociative moments, impulsivity and body dissatisfaction. However, alexithymia remains unchanged, possibly because of its deep emotional nature.

Comparison of Collisional and Electron-Based Dissociation Modes for Middle-Down Analysis of Multiply Glycosylated Peptides

NASA Astrophysics Data System (ADS)

Khatri, Kshitij; Pu, Yi; Klein, Joshua A.; Wei, Juan; Costello, Catherine E.; Lin, Cheng; Zaia, Joseph

2018-04-01

Analysis of singly glycosylated peptides has evolved to a point where large-scale LC-MS analyses can be performed at almost the same scale as proteomics experiments. While collisionally activated dissociation (CAD) remains the mainstay of bottom-up analyses, it performs poorly for the middle-down analysis of multiply glycosylated peptides. With improvements in instrumentation, electron-activated dissociation (ExD) modes are becoming increasingly prevalent for proteomics experiments and for the analysis of fragile modifications such as glycosylation. While these methods have been applied for glycopeptide analysis in isolated studies, an organized effort to compare their efficiencies, particularly for analysis of multiply glycosylated peptides (termed here middle-down glycoproteomics), has not been made. We therefore compared the performance of different ExD modes for middle-down glycopeptide analyses. We identified key features among the different dissociation modes and show that increased electron energy and supplemental activation provide the most useful data for middle-down glycopeptide analysis. [Figure not available: see fulltext.

Dissociative Experiences are Associated with Obsessive-Compulsive Symptoms in a Non-clinical Sample: A Latent Profile Analysis

PubMed Central

BOYSAN, Murat

2014-01-01

Introduction There has been a burgeoning literature considering the significant associations between obsessive-compulsive symptoms and dissociative experiences. In this study, the relationsips between dissociative symtomotology and dimensions of obsessive-compulsive symptoms were examined in homogeneous sub-groups obtained with latent class algorithm in an undergraduate Turkish sample. Method Latent profile analysis, a recently developed classification method based on latent class analysis, was applied to the Dissociative Experiences Scale (DES) item-response data from 2976 undergraduates. Differences in severity of obsessive-compulsive symptoms, anxiety and depression across groups were evaluated by running multinomial logistic regression analyses. Associations between latent class probabilities and psychological variables in terms of obsessive-compulsive sub-types, anxiety, and depression were assessed by computing Pearson’s product-moment correlation coefficients. Results The findings of the latent profile analysis supported further evidence for discontinuity model of dissociative experiences. The analysis empirically justified the distinction among three sub-groups based on the DES items. A marked proportion of the sample (42%) was assigned to the high dissociative class. In the further analyses, all sub-types of obsessive-compulsive symptoms significantly differed across latent classes. Regarding the relationships between obsessive-compulsive symptoms and dissociative symptomatology, low dissociation appeared to be a buffering factor dealing with obsessive-compulsive symptoms; whereas high dissociation appeared to be significantly associated with high levels of obsessive-compulsive symptoms. Conclusion It is concluded that the concept of dissociation can be best understood in a typological approach that dissociative symptomatology not only exacerbates obsessive-compulsive symptoms but also serves as an adaptive coping mechanism. PMID:28360635

Dissociative Experiences are Associated with Obsessive-Compulsive Symptoms in a Non-clinical Sample: A Latent Profile Analysis.

PubMed

Boysan, Murat

2014-09-01

There has been a burgeoning literature considering the significant associations between obsessive-compulsive symptoms and dissociative experiences. In this study, the relationsips between dissociative symtomotology and dimensions of obsessive-compulsive symptoms were examined in homogeneous sub-groups obtained with latent class algorithm in an undergraduate Turkish sample. Latent profile analysis, a recently developed classification method based on latent class analysis, was applied to the Dissociative Experiences Scale (DES) item-response data from 2976 undergraduates. Differences in severity of obsessive-compulsive symptoms, anxiety and depression across groups were evaluated by running multinomial logistic regression analyses. Associations between latent class probabilities and psychological variables in terms of obsessive-compulsive sub-types, anxiety, and depression were assessed by computing Pearson's product-moment correlation coefficients. The findings of the latent profile analysis supported further evidence for discontinuity model of dissociative experiences. The analysis empirically justified the distinction among three sub-groups based on the DES items. A marked proportion of the sample (42%) was assigned to the high dissociative class. In the further analyses, all sub-types of obsessive-compulsive symptoms significantly differed across latent classes. Regarding the relationships between obsessive-compulsive symptoms and dissociative symptomatology, low dissociation appeared to be a buffering factor dealing with obsessive-compulsive symptoms; whereas high dissociation appeared to be significantly associated with high levels of obsessive-compulsive symptoms. It is concluded that the concept of dissociation can be best understood in a typological approach that dissociative symptomatology not only exacerbates obsessive-compulsive symptoms but also serves as an adaptive coping mechanism.

Core schemas and suicidality in a chronically traumatized population.

PubMed

Dutra, Lissa; Callahan, Kelley; Forman, Evan; Mendelsohn, Michaela; Herman, Judith

2008-01-01

The Young Schema Questionnaire (YSQ) has been demonstrated to tap into core beliefs, or maladaptive schemas, of clinical populations. This study used the YSQ to investigate maladaptive schemas of 137 chronically traumatized patients seeking outpatient psychiatric treatment and to assess whether specific schemas might be associated with suicide risk in this population. Participants completed a modified version of the YSQ-S (short form), post-traumatic diagnostic scale, dissociative experiences scale and self-harm and risk behaviors questionnaire-revised at treatment intake. Significant correlations were found between most YSQ scales and the post-traumatic diagnostic scale, and between all YSQ scales and the dissociative experiences scale. Suicide risk variables were most highly correlated with the social isolation/alienation, defectiveness/shame and failure YSQ scales, suggesting that these schemas may mark individuals at particularly high risk for suicidal ideation and suicide attempts. These results offer important implications for the assessment and treatment of high-risk traumatized patients.

Dissociative disorders and dissociative symptoms among veterans of the Iraq-Iran war suffering from chronic post-traumatic disorder.

PubMed

Nejad, Alireza G; Farahati, Hamid

2007-10-01

To evaluate any dissociative disorders in patients with post traumatic stress disorder (PTSD), and find any relationship between dissociation and related variables in these patients. A case controlled study carried out among 130 male patients with PTSD, and 130 matched individuals from the normal population. The study was carried out between January and September 2005, at Beheshti Psychiatric Hospital, Kerman, Iran, Demographic data and history of childhood physical abuse and self-harm in both groups were recorded. The severity of PTSD was measured by Davidson PTSD scale in the study group. Dissociative symptoms were evaluated with the dissociative experience scale (DES). For evaluating dissociative disorders, the dissociative disorder interview schedule (DDIS) was used. Data were analyzed by SPSS software. The mean age (+/- SD) of veterans was 41.46 (+/-5.09) years, and the mean age of going to the combat area was 29.4 (+/-5.015). The mean duration of involvement in combat was 27.8 (+/-23.44) months. The mean DES score in the study group was 26.01 (+/-12.31) and was 9.58 (+/-7.23) in the control group (F=1.171, p<0.0001). The mean score (+/-SD) of Davidson PTSD scale was 54+/-96 in the study group. The most prevalent dissociative disorder in the study group was psychogenic amnesia. Many veterans with the impression of chronic PTSD may have an additional diagnosis of dissociative disorders.

Dissociative experiences in epilepsy--a neuropathological and sociodemographic study in a Chinese population.

PubMed

Wang, Yan-Gang; Li, Zhiling; Zhang, Wei; Prakash, Ravi

2014-08-01

It is well known that dissociative experiences coexist with various epilepsy syndromes. However, the prevalence of dissociative experiences in different subtypes of epilepsy remains unknown. This is especially important because of the current prevalent view that the etiology of dissociation in seizures is neurobiological rather than psychosocial. The amygdala especially has been implicated in such dissociative features of epilepsy. This would indirectly imply that the patients with CPS have higher prevalence of dissociative symptoms compared with those with GTCS. We studied and compared the dissociative experiences as well as the depression and anxiety levels between 24 patients suffering from temporal lobe epilepsy and 26 patients suffering from generalized tonic-clonic seizures. We used the Dissociative Experiences Scale to evaluate the dissociative experiences. A third group of healthy individuals was included as the control group. The statistical significance was fixed at 0.05. There were significant differences between the scores of DES-II of the healthy individuals and those of patients with epilepsy. However, there were no significant differences between the DES scores of different patients with epilepsy categorized according to neuropathology. There were also no significant differences between HAM-A and HAM-D scores between groups with epilepsy, but the scores were higher than those of the healthy individuals. There were significant differences between the DES scores in different sociodemographic groups such that higher scores were observed in groups with lower education (p<0.05). In addition, the scores on DES were higher in individuals with low socioeconomic status than in those with high socioeconomic status. The patients with temporal lobe epilepsy and those with generalized tonic-clonic seizures have similar dissociative experiences which are both more than those found in individuals without epilepsy. However, these dissociative experiences may not be related to the neuropathological parameters as much as they are to the sociodemographic parameters like education, age, socioeconomic status, and sex. This shows that the psychopathology of dissociation in epilepsy is similar to that of the general population. Copyright © 2014. Published by Elsevier Inc.

Self-reports of trauma and dissociation: An examination of context effects.

PubMed

Lemons, Peter; Lynn, Steven Jay

2016-08-01

To examine context effects in moderating the link between self-reported trauma and dissociation in undergraduate samples, we administered these measures either in the same or different experimental contexts. Trauma History Screen/THS (Carlson et al., 2011)-Dissociative Experiences Scale/DES-II (Bernstein & Putnam, 1986) correlations revealed a context effect (greater correlations in same test context), although multiple regression analyses did not confirm this finding. A context effect was supported in DES-Taxon scores using multiple regression for the THS but not the Modified Posttraumatic Stress Scale (MPSS-SR; Falsetti, Resnick, Resick, & Kilpatrick, 1993), an effect confirmed with correlation comparisons. Ethnicity influenced the association between measures of trauma and dissociation. Overall, the relation between measures of trauma and dissociation was small to medium, although high correlations were observed between the DES depersonalization/derealization subscale and the Multiscale Dissociation Inventory (Briere, Weathers, & Runtz, 2005) depersonalization and derealization subscales, supporting the construct validity of these measures. Copyright © 2016 Elsevier Inc. All rights reserved.

Dissociation as a mediator of child abuse across generations.

PubMed

Egeland, B; Susman-Stillman, A

1996-11-01

To test the hypothesis that dissociative process is the mechanism that accounts for the transmission of maltreatment across generations, a group of mothers who were abused and maltreated their children were compared to a group of mothers who broke the cycle of abuse. Mothers who were abused and are abusing their children were rated higher on idealization, inconsistency, and escapism in their description of their childhood and they scored higher on the Dissociative Experience Scale compared to mothers who broke the cycle. Mothers who were abused and abused their children recalled the care they received as children in a fragmented and disconnected fashion whereas those who broke the cycle integrated their abusive experience into a more coherent view of self. Even after partialing out the effects of IQ, large differences were found indicating that dissociative process plays a part in the transmission of maltreatment across generations. Possible reasons why some maltreated individuals coped with the trauma by dissociating and others integrate the experience were discussed.

High psychiatric comorbidity in adolescents with dissociative disorders.

PubMed

Bozkurt, Hasan; Duzman Mutluer, Tuba; Kose, Cigdem; Zoroglu, Salih

2015-06-01

The aim of this study was to evaluate psychiatric comorbidity rates and patterns in a sample of clinically referred adolescents diagnosed with dissociative disorders (DD) by using a structured interview. All participants completed a comprehensive test battery, which consisted of a questionnaire for sociodemographic data and clinical history, Child Posttraumatic Stress Reaction Index, Childhood Abuse and Neglect Questionnaire and the Adolescent Dissociative Experiences Scale. Diagnosis was made by the Structured Clinical Interview for DSM-IV Dissociative Disorders. Psychiatric comorbidity was assessed using the Schedule for Affective Disorders and Schizophrenia for School Age Children - Present and Lifetime Version. A total of 25 adolescent subjects aged 12-18 years participated in the study. Ten adolescents were diagnosed as having dissociative identity disorder and 15 of them were diagnosed as having dissociative disorder-not otherwise specified based on the Structured Clinical Interview for DSM-IV Dissociative Disorders findings. Adolescents with dissociative identity disorder were found to have higher scores on the Adolescent Dissociative Experiences Scale and Child Posttraumatic Stress Reaction Index than the dissociative disorder-not otherwise specified group. Sexual and physical abuses were also found to be among the main traumatic events. Incest was reported in six cases of the study sample. All subjects had at least one comorbid psychiatric disorder. The most common psychiatric diagnoses were major depressive disorder (n = 25; 100%) and post-traumatic stress disorder (n = 22; 88%). High psychiatric comorbidity rates were found in adolescents diagnosed with DD. A prevalent history of abuse and traumatic events was represented. Clinicians should be aware of the impacts of DD on adolescents' mental health. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology.

Extrasensory Perception Experiences and Childhood Trauma: A Rorschach Investigation.

PubMed

Scimeca, Giuseppe; Bruno, Antonio; Pandolfo, Gianluca; La Ciura, Giulia; Zoccali, Rocco A; Muscatello, Maria R A

2015-11-01

This study investigated whether people who report recurrent extrasensory perception (ESP) experiences (telepathy, clairvoyance, and precognition) have suffered more traumatic experiences and traumatic intrusions. Thirty-one nonclinical participants reporting recurrent ESP experiences were compared with a nonclinical sample of 31 individuals who did not report recurrent ESP phenomena. Past traumatic experiences were assessed via a self-report measure of trauma history (Childhood Trauma Questionnaire); traumatic intrusions were assessed via a performance-based personality measure (Rorschach Traumatic Content Index). Participants also completed the Anomalous Experience Inventory, the Minnesota Multiphasic Personality Inventory-2, the Dissociative Experience Scale, and the Revised Paranormal Belief Scale. The ESP group reported higher levels of emotional abuse, sexual abuse, emotional neglect, physical neglect, and traumatic intrusions. The association between ESP experiences and trauma was partly mediated by the effects of dissociation and emotional distress. Implications for health professionals are discussed. Results also showed the reliability of the twofold method of assessment of trauma.

Psychiatric symptoms and dissociation in conversion, somatization and dissociative disorders.

PubMed

Espirito-Santo, Helena; Pio-Abreu, Jose Luis

2009-03-01

Conversion, dissociation and somatization are historically related in the long established concept of hysteria. Somewhere along the way they were separated due to the Cartesian dualistic view. The aim of the present study was to compare these pathologies and investigate whether symptoms of these pathologies overlap in their clinical appearance in a Portuguese sample. Twenty-six patients with conversion disorder, 38 with dissociative disorders, 40 with somatization disorder, and a comparison group of 46 patients having other psychiatric disorders answered questions about dissociation (Dissociative Experiences Scale), somatoform dissociation (Somatoform Dissociation Questionnaire), and psychopathological symptoms (Brief Symptom Inventory). Dissociative and somatoform symptoms were significantly more frequent in dissociative and conversion disorder than in somatization disorder and controls. There were no significant differences between dissociative and conversion patients. Conversion disorder is closely related to dissociative disorders. These results support the ICD-10 categorization of conversion disorder among dissociative disorders and the hypothesis of analogous psychopathological processes in conversion and dissociative disorders versus somatization disorder.

Mechanism of Phosphine Dissociation on the Si(001) Surface

NASA Astrophysics Data System (ADS)

Warschkow, Oliver; Schofield, Steven R.; Smith, Phil V.

2005-03-01

The continued down-scaling of electronic devices to the atomic scale increasingly requires an atomic-level understanding of the elementary processes of semiconductor doping. We present a combined experimental and theoretical investigation into the dissociation mechanism of phosphine (PH3) on the Si(001) surface. As reported by us elsewhere in this conference, a number of prominent intermediate species of PH3 dissociation observed in STM experiments have been structurally characterized as PH2+H, PH+2H and P+3H species respectively. In this poster we present detailed quantum chemical calculations of these and other short-lived intermediates as well as the transition (kinetic) barriers between them. This leads us to formulate a step-by-step mechanism for the complete dissociation of PH3 on the Si(001) surface.

Validation of the Italian version of the dissociative experience scale for adolescents and young adults.

PubMed

De Pasquale, Concetta; Sciacca, Federica; Hichy, Zira

2016-01-01

The Dissociative Experience Scale for adolescent (A-DES), a 30-item, multidimensional, self-administered questionnaire, was validated using a large sample of American young people sample. We reported the linguistic validation process and the metric validity of the Italian version of A-DES in the Italy. A set of questionnaires was provided to a total of 633 participants from March 2015 to April 2016. The participants consisted of 282 boys and 351 girls, and their average age was between 18 and 24 years old. The translation process consisted of two consecutive steps: forward-backward translation and acceptability testing. The psychometric testing was applied to Italian students who were recruited from the Italian Public Schools and Universities in Sicily. Informed consent was obtained from all participants at the research. All individuals completed the A-DES. Reliability and validity were tested. The translated version was validated on a total of 633 Italian students. The reliability of A-DES total is .926. It is composed by 4 subscales: Dissociative amnesia, Absorption and imaginative involvement, Depersonalization and derealization, and Passive influence. The reliability of each subscale is: .756 for dissociative amnesia, .659 for absorption and imaginative involvement, .850 for depersonalization and derealization, and .743 for passive influence. The Italian version of the A-DES constitutes a useful instrument to measure dissociative experience in adolescents and young adults in Italy.

Dissociative Experiences during Sexual Behavior among a Sample of Adults Living with HIV Infection and a History of Childhood Sexual Abuse

PubMed Central

Hansen, Nathan B.; Brown, Lauren J.; Tsatkin, Elizabeth; Zelgowski, Brittany; Nightingale, Vienna

2012-01-01

Little attention has been given to the occurrence of dissociative symptoms during sexual behavior in adults who have experienced childhood sexual abuse (CSA). For this study, 57 adults living with HIV infection who had experienced CSA and were entering a treatment study for traumatic stress completed study assessments and clinical interviews, including a 15-item scale of Dissociative Experiences during Sexual Behavior. Predictor variables included DSM-IV-TR diagnoses of PTSD and Dissociative Disorders, Rape by an Intimate Partner, Duration of CSA, Number of Perpetrators of CSA, and Current Sexual Satisfaction. A multiple regression analysis was conducted to identify significant associations between predictors and dissociation during sex. Mean differences by clinical diagnosis were also examined. Results indicated that PTSD, Dissociative Disorders, Rape by an Intimate Partner, Duration of CSA, and Number of Perpetrators of CSA were associated with increased dissociation during sexual behavior. Dissociation during sex likely increases vulnerability to sexual revictimization and risky sexual behavior. Standard behavioral prevention interventions may be ineffective for sexual situations when dissociation occurs, and prevention efforts should be integrated with mental health care for those who have experienced CSA. PMID:22545567

Etiology and clinical course of pseudoseizures. Relationship to trauma, depression, and dissociation.

PubMed

Bowman, E S

1993-01-01

Twenty-seven outpatients with video-EEG-documented pseudoseizures were interviewed by a psychiatrist to determine the historical course of seizures and diagnose the current presence of these DSM-III-R diagnoses: affective disorders (85%), dissociative disorders (85%), and posttraumatic stress disorder (33%). Their mean (26.7) and median (26.9) Dissociative Experiences Scale scores were elevated. Eighty-eight percent of subjects had sustained significant trauma, including sexual abuse/rape (77%) and physical abuse (70%). Four psychodynamic pathways to pseudoseizures were noted. Most commonly, pseudoseizures originated from dissociated personalities or ego states, were expressions of dissociated memories of child abuse, and were triggered by recent stresses or traumas.

Dissociative symptomatology in cancer patients.

PubMed

Civilotti, Cristina; Castelli, Lorys; Binaschi, Luca; Cussino, Martina; Tesio, Valentina; Di Fini, Giulia; Veglia, Fabio; Torta, Riccardo

2015-01-01

The utilization of the post-traumatic stress disorder (PTSD) diagnostic spectrum is currently being debated to categorize psychological adjustment in cancer patients. The aims of this study were to: (1) evaluate the presence of cancer-related traumatic dissociative symptomatology in a sample of cancer patients; (2) examine the correlation of cancer-related dissociation and sociodemographic and medical variables, anxiety, depression, and post-traumatic stress symptomatology; (3) investigate the predictors of cancer-related dissociation. Ninety-two mixed cancer patients (mean age: 58.94, ds = 10.13) recruited from two hospitals in northern Italy were administered a questionnaire on sociodemographic and medical characteristics, the Karnofsky Scale to measure the level of patient activity and medical care requirements, the Hospital Anxiety and Depression Scale (HADS) to evaluate the presence of anxiety and depression, the Impact of Event Scale Revised (IES-R) to assess the severity of intrusion, avoidance, and hypervigilance, and the Peritraumatic Dissociative Experiences Questionnaire (PDEQ) to quantify the traumatic dissociative symptomatology. 31.5% of participants report a PDEQ score above the cutoff. The results indicated that dissociative symptomatology was positively correlated with HADS scores (HADS-Anxiety: r = 0.476, p < 0.001; HADS-Depression: r = 0.364, p < 0.001) and with IES-R scores (IES-R-Intrusion: r = 0.698, p < 0.001; IES-R-Avoidance: r = 0.619, p < 0.001; IES-R- Hypervigilance: r = 0.681, p < 0.001). A stepwise regression analysis was performed in order to find the predictors of cancer-related traumatic dissociative symptomatology. The results converged on a three predictor model revealing that IES-R-Intrusion, IES-R-Avoidance, and IES-R-Hyperarousal accounted for 53.9% of the explained variance. These findings allow us to hypothesize a specific psychological reaction which may be ascribed to the traumatic spectrum within the context of cancer, emphasizing the close relationship between the origin of dissociative constituents which, according to the scientific literature, compose the traumatic experience. Our results have implications for understanding dissociative symptomatology in a cancer population and can help develop clinical programs of prevention and support for patients.

Attachment insecurity as a mediator of the relationship between childhood trauma and adult dissociation.

PubMed

Kong, Seong Sook; Kang, Dae Ryong; Oh, Min Jung; Kim, Nam Hee

2018-01-01

This study aimed to investigate whether attachment insecurity mediates the relationship between childhood trauma and adult dissociation, specifically with regard to individual forms of childhood maltreatment. Psychiatric outpatients who visited a specialized trauma clinic (n = 115) participated in the study. Data were collected via the Childhood Trauma Questionnaire, Revised Adult Attachment Scale, and Dissociative Experience Scale. Structural equation modeling and path analysis were performed to analyze the mediating effects of attachment insecurity on the relationship between childhood trauma and adult dissociation. Greater childhood trauma was associated with higher dissociation, and the relationship between them was fully mediated by attachment anxiety. In path analysis of trauma subtypes, the effects of emotional abuse, physical abuse, and physical neglect as a child on adult dissociation were found to be fully mediated by attachment anxiety. The effect of sexual abuse on dissociation was mediated by a synergistic effect from both attachment anxiety and attachment avoidance. Regarding emotional neglect, a countervailing interaction was discovered between the direct and indirect effects thereof on dissociation; the indirect effect of emotional neglect on dissociation was partially mediated by attachment insecurity. Specific aspects of attachment insecurity may help explain the relationships between individual forms of childhood trauma and adult dissociative symptoms. Tailored treatments based on affected areas of attachment insecurity may improve outcomes among patients with dissociative symptoms and a history of childhood trauma.

Dancing with the Muses: dissociation and flow.

PubMed

Thomson, Paula; Jaque, S Victoria

2012-01-01

This study investigated dissociative psychological processes and flow (dispositional and state) in a group of professional and pre-professional dancers (n=74). In this study, high scores for global (Mdn=4.14) and autotelic (Mdn=4.50) flow suggest that dancing was inherently integrating and rewarding, although 17.6% of the dancers were identified as possibly having clinical levels of dissociation (Dissociative Experiences Scale-Taxon cutoff score≥20). The results of the multivariate analysis of variance indicated that subjects with high levels of dissociation had significantly lower levels of global flow (p<.05). Stepwise linear regression analyses demonstrated that dispositional flow negatively predicted the dissociative constructs of depersonalization and taxon (p<.05) but did not significantly predict the variance in absorption/imagination (p>.05). As hypothesized, dissociation and flow seem to operate as different mental processes.

Dissociation as a Mediator of Child Abuse across Generations.

ERIC Educational Resources Information Center

Egeland, Byron; Susman-Stillman, Amy

1996-01-01

Eleven mothers who were abused and maltreated their children were compared to 10 mothers who broke the cycle of abuse. The abusing mothers were rated higher on idealization, inconsistency, and escapism in their description of their childhood, and they scored higher on the Dissociative Experience Scale than the comparison mothers. (DB)

Depersonalisation and schizophrenia: Comparative study of initial and multiple episodes of schizophrenia.

PubMed

Luque-Luque, Rogelio; Chauca-Chauca, Geli Marie; Alonso-Lobato, Pablo; Jaen-Moreno, M Jose

2016-01-01

The phenomena of depersonalisation/derealisation have classically been associated with the initial phases of psychosis, and it is assumed that they would precede (even by years) the onset of clinical psychosis, being much more common in the prodromal and acute phases of the illness. The aims of the present study are to analyse the differences in depersonalisation/derealisation between patients with initial and multiple episodes and the factors that could influence this. A descriptive, controlled and cross-sectional study of 48 patients diagnosed with paranoid schizophrenia (20 with an initial episode and 28 with multiple episodes). These patients were assessed using scales such as the Cambridge Depersonalization Scale, the Positive and Negative Symptom Scale, and the Dissociative Experiences Scale. Participants with initial episodes score higher on both the Cambridge Depersonalisation Scale, and the subscale of the Dissociative Experiences Scale that evaluates such experiences. There were no associations between these types of experience and the positive symptoms subscale of the Positive and Negative Symptom Scale. Depersonalisation/derealisation experiences appear with greater frequency, duration and intensity in patients in the early stages of the illnesses, gradually decreasing as they become chronic. Copyright © 2016 SEP y SEPB. Published by Elsevier España. All rights reserved.

Childhood sexual and physical abuse and adult vulnerability to PTSD: the mediating effects of attachment and dissociation.

PubMed

Twaite, James A; Rodriguez-Srednicki, Ofelia

2004-01-01

Two hundred and eighty-four adults from the metropolitan New York area reported on their history of childhood sexual abuse (CSA), childhood physical abuse (CPA), and on the nature of their exposure to the terrorist attack on the World Trade Center. The respondents also completed the Impact of Events Scale-Revised (IES-R), the Attachment Style Questionnaire (ASQ) and the Dissociative Experiences Scale (DES). Those reporting histories of CSA and/or CPA were found to endorse more serious symptoms of PTSD, as did those who witnessed the terrorist attack live. The presence of secure attachments and dissociative symptoms were related significantly to both CSA and CPA, and to scores on the IES-R. Adult attachment and dissociation were found to mediate the relationship between childhood abuse and severity of PTSD.

Fractionating the unitary notion of dissociation: disembodied but not embodied dissociative experiences are associated with exocentric perspective-taking

PubMed Central

Braithwaite, Jason J.; James, Kelly; Dewe, Hayley; Medford, Nick; Takahashi, Chie; Kessler, Klaus

2013-01-01

It has been argued that hallucinations which appear to involve shifts in egocentric perspective (e.g., the out-of-body experience, OBE) reflect specific biases in exocentric perspective-taking processes. Via a newly devised perspective-taking task, we examined whether such biases in perspective-taking were present in relation to specific dissociative anomalous body experiences (ABE) – namely the OBE. Participants also completed the Cambridge Depersonalization Scale (CDS; Sierra and Berrios, 2000) which provided measures of additional embodied ABE (unreality of self) and measures of derealization (unreality of surroundings). There were no reliable differences in the level of ABE, emotional numbing, and anomalies in sensory recall reported between the OBE and control group as measured by the corresponding CDS subscales. In contrast, the OBE group did provide significantly elevated measures of derealization (“alienation from surroundings” CDS subscale) relative to the control group. At the same time we also found that the OBE group was significantly more efficient at completing all aspects of the perspective-taking task relative to controls. Collectively, the current findings support fractionating the typically unitary notion of dissociation by proposing a distinction between embodied dissociative experiences and disembodied dissociative experiences – with only the latter being associated with exocentric perspective-taking mechanisms. Our findings – obtained with an ecologically valid task and a homogeneous OBE group – also call for a re-evaluation of the relationship between OBEs and perspective-taking in terms of facilitated disembodied experiences. PMID:24198776

Dissociation, childhood trauma, and ataque de nervios among Puerto Rican psychiatric outpatients.

PubMed

Lewis-Fernández, Roberto; Garrido-Castillo, Pedro; Bennasar, Mari Carmen; Parrilla, Elsie M; Laria, Amaro J; Ma, Guoguang; Petkova, Eva

2002-09-01

This study examined the relationships of dissociation and childhood trauma with ataque de nervios. Forty Puerto Rican psychiatric outpatients were evaluated for frequency of ataque de nervios, dissociative symptoms, exposure to trauma, and mood and anxiety psychopathology. Blind conditions were maintained across assessments. Data for 29 female patients were analyzed. Among these 29 patients, clinician-rated dissociative symptoms increased with frequency of ataque de nervios. Dissociative Experiences Scale scores and diagnoses of panic disorder and dissociative disorders were also associated with ataque frequency, before corrections were made for multiple comparisons. The rate of childhood trauma was uniformly high among the patients and showed no relationship to dissociative symptoms and disorder or number of ataques. Frequent ataques de nervios may, in part, be a marker for psychiatric disorders characterized by dissociative symptoms. Childhood trauma per se did not account for ataque status in this group of female outpatients.

Body Esteem as a Common Factor of a Tendency Toward Binge Eating and Sexual Dissatisfaction Among Women: The Role of Dissociation and Stress Response During Sex.

PubMed

Castellini, Giovanni; Lo Sauro, Carolina; Ricca, Valdo; Rellini, Alessandra H

2017-08-01

Several studies have suggested a relevant overlap between eating disorders and sexual dysfunction involving the emotional component of body image esteem and dissociative experiences. To evaluate the common maintaining factors of sexual dysfunction and vulnerability to pathologic eating behaviors and their relation to a physiologic stress response. In the present cross-sectional study, we evaluated a non-clinical sample of 60 heterosexual women (25-35 years old) for dissociation during sex with a partner, body image disturbance, and tendency toward pathologic eating behaviors. We also evaluated the stress-induced hypothalamic-pituitary-adrenal axis activation in response to a sexual stimulus and its association with binge eating and dissociation. Participants completed the Clinician-Administered Dissociative States Scale, the Sexual Satisfaction Scale-Women, the Body Esteem Scale for Adolescents and Adults, and the Eating Attitudes Test Short Version. Furthermore, we assessed cortisol levels before, during, and after exposure to explicit sexual stimuli shown within a laboratory setting. Dysfunctional body image esteem and a tendency toward binge-eating behaviors were associated with greater sexual distress in women. In particular, body esteem was significantly associated with greater dissociation during sex with a partner. Moreover, women who reported greater dissociation during sex with a partner and a tendency toward binge-eating behaviors showed higher levels of cortisol in response to sexual stimuli. These results support further research based on trans-diagnostic treatments targeted to dissociation and body image esteem, which could lessen sexual dysfunction and vulnerability to pathologic eating behaviors. Despite the small sample and self-reported questionnaires, this is the first study to consider the association of the stress response during sexual stimuli with sexual distress and with pathologic eating behaviors adopting a dimensional approach. Body uneasiness and dissociation represented factors underlying pathologic eating behaviors and sexual dysfunction. Women reporting a tendency toward binge-eating episodes and dissociation during sexual experiences represented a subpopulation with a higher stress response during sexual stimuli. Castellini G, Lo Sauro C, Ricca V, Rellini AH. Body Esteem as a Common Factor of a Tendency Toward Binge Eating and Sexual Dissatisfaction Among Women: The Role of Dissociation and Stress Response During Sex. J Sex Med 2017;14:1036-1045. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Dissociative experiences during sexual behavior among a sample of adults living with HIV infection and a history of childhood sexual abuse.

PubMed

Hansen, Nathan B; Brown, Lauren J; Tsatkin, Elizabeth; Zelgowski, Brittany; Nightingale, Vienna

2012-01-01

Little attention has been given to the occurrence of dissociative symptoms during sexual behavior in adults who have experienced childhood sexual abuse (CSA). For this study, 57 adults living with HIV infection who had experienced CSA and were entering a treatment study for traumatic stress completed study assessments and clinical interviews, including a 15-item scale of dissociative experiences during sexual behavior. Predictor variables included Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision diagnoses of posttraumatic stress disorder (PTSD) and dissociative disorders, rape by an intimate partner, duration of CSA, number of perpetrators of CSA, and current sexual satisfaction. A multiple regression analysis was conducted to identify significant associations between predictors and dissociation during sex. Mean differences by clinical diagnosis were also examined. Results indicated that PTSD, dissociative disorders, rape by an intimate partner, duration of CSA, and number of perpetrators of CSA were associated with increased dissociation during sexual behavior. Dissociation during sex likely increases vulnerability to sexual revictimization and risky sexual behavior. Standard behavioral prevention interventions may be ineffective for sexual situations when dissociation occurs, and prevention efforts should be integrated with mental health care for those who have experienced CSA.

The Association among Childhood Trauma, Pathological Dissociation and Gambling Severity in Casino Gamblers.

PubMed

Imperatori, Claudio; Innamorati, Marco; Bersani, Francesco Saverio; Imbimbo, Francesca; Pompili, Maurizio; Contardi, Anna; Farina, Benedetto

2017-01-01

The aim of the present study was to explore the role of pathological dissociation in mediating the association between childhood trauma (CT) and gambling severity. One hundred seventy-one (134 men and 37 women) gamblers recruited in gambling environments (i.e., two Italian casinos) have been enrolled in the study. Psychopathological assessments included the Childhood Trauma Questionnaire (CTQ), the Dissociative Experiences Scale-Taxon (DES-T), the South Oaks Gambling Screen (SOGS), the CAGE and the Hospital Anxiety and Depression Scale. A mediational model, analyzing the direct and indirect effects of CTQ on SOGS through the mediating role of DES-T, showed that the relation between CTQ and SOGS was fully mediated by DES-T scores (b = 0.07; se = 0.15; p < 0.001). This finding raises the possibility that CT explains gambling severity through the presence of pathological dissociative symptoms and dissociative pathogenetic processes. Copyright © 2015 John Wiley & Sons, Ltd. Gambling severity is associated with both childhood trauma and pathological dissociation in casino gamblers. A mediational model shows that the effect of childhood trauma on gambling severity is entirely mediated by pathological dissociation. From a clinical point of view, our results highlight the importance of assessing, and possibly treating, dissociative symptoms in individuals with gambling disorder. Copyright © 2015 John Wiley & Sons, Ltd.

Psychogenic non-epileptic seizures and functional motor symptoms: A common phenomenology?

PubMed

Demartini, Benedetta; Goeta, Diana; Barbieri, Valentina; Ricciardi, Lucia; Canevini, Maria Paola; Turner, Katherine; D'Agostino, Armando; Romito, Luigi; Gambini, Orsola

2016-09-15

Recent studies have attempted to compare patients affected by psychogenic non-epileptic seizures (PNES) to patients affected by functional motor symptoms (FMS) from a demographic, clinical and psychological perspective. Nevertheless, results are quite controversial and significant conclusions have not been drawn. The aim of our study was to evaluate the phenomenology of psychology of the two groups assessing levels of dissociation and its subcomponents, alexithymia and interoceptive sensitivity in patients with PNES and in patients with FMS. We conducted a cross-sectional study recruiting 20 patients with PNES, 20 patients with FMS and 20 healthy subjects as a control group. All subjects underwent: Dissociative Experience Scale (DES), Somatoform Dissociation Questionnaire (SDQ-20), Cambridge Depersonalization Scale (CDS), Toronto Alexithymia Scale (TAS-20), Hamilton Rating Scale for Depression (HAM-D), Hamilton Rating Scale for anxiety (HAM-A), heart beat detection task. Our data suggest that PNES group scored significantly higher than the healthy control group on a measure of detachment (CDS). Also at the DES, a measure of psychoform dissociation, PNES patients scored significantly higher than healthy subjects. On the other hand patients affected by FMS scored significantly higher than the healthy control group on the SDQ but they did not report more experiences of detachment on the CDS. Patients affected by PNES and FMS were significantly more alexithymic than healthy controls, with a third of them scoring >61 on the TAS-20. Our data show different psychological mechanisms underlying patients with PNES and patients with FMS. This might lead also to potential implications for treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of Relationship between Obsessive-compulsive Disorder and Dissociative Experiences.

PubMed

Tatlı, Mustafa; Cetinkaya, Ozlem; Maner, Fulya

2018-05-31

The aim of the study is to evaluate the relationship between obsessive-compulsive disorder (OCD) symptoms and dissociative experiences and the effect of childhood traumatic experiences on this relationship in OCD patients. Fifty consecutive OCD patients and 50 healthy controls are enrolled for this study. Sociodemographic and Clinical Data Form, Dissociative Experiences Scale (DES), Padua Inventory (PI) and Childhood Trauma Questionnaire (CTQ) are applied to participants. Average DES total score in the patient group is 20.58 and in the control group it is 4.87. In the patient group, when we evaluate the relation strengths of DES total and subscale scores with PI total score, we found out that amnesia subscale has r=0.361 ( p <0.01), absorption subscale has r=0.611 ( p <0.01), depersonalization/derealization subscale has r=0.574 ( p <0.01), and DES total score has r=0.55 ( p <0.01) relation strengths with PI total score. In patient group both DES total score and CTQ total score have influence on PI total score independently from each other. In addition to this, the level of the influence of DES total scores on PI total scores is, R²=0.399 ( p <0.01) and the level of the influence of CTQ total scores on PI total scores is R²=0.343 ( p <0.01). Dissociative experiences are seen more frequently in OCD patients than healthy controls. Among dissociative experiences, absorption has stronger relation with OCD symptoms. The relation between OCD and dissociation is independent from and stronger than the relation between childhood traumatic experiences and OCD.

Partial mediator role of physical abuse on the relationship between attention-deficit/hyperactivity disorder symptoms and severity of dissociative experiences in a sample of inpatients with alcohol use disorder

PubMed Central

Evren, Cuneyt; Umut, Gokhan; Bozkurt, Muge; Can, Yesim; Evren, Bilge; Agachanli, Ruken

2017-01-01

Aim: This study aimed to evaluate the relationship of attention-deficit/hyperactivity disorder (ADHD) symptoms with dissociative experiences, and the mediator role of childhood traumas on this relationship, while controlling the effect of depression in alcohol use disorder (AUD). Settings and Design: It was a hospital-based, cross-sectional study. Materials and Methods: One hundred and ninety inpatients with AUD were evaluated with the Beck Depression Inventory, the Adult ADHD Self-Report Scale (ASRS), Childhood Trauma Qestionnaire, and Dissociative Experiences Scale (DES). Statistical Analysis: One-way ANOVA, Chi-squared test, and hierarchical linear regression model were performed. Results: The ratio of those who receive 10 points or less from DES was 26.8%, those who receive points between 11 and 30 was 45.3%, and those who receive more than 30 points was 27.9%. The latter group that was considered as a group with high risk of dissociative disorder had higher scores from depression, childhood trauma, and ADHD scores than the other groups. Rate of those with high probability of ADHD was higher among this group. ASRS total score and inattentive subscale scores were moderately (r = 0.552 and r = 0.547, respectively) and hyperactive/impulsive subscale was mildly (r = 0.430) correlated with DES score. Severity of ADHD was related with the severity of dissociative symptoms, and physical abuse had partial mediator effect on this relationship, even after controlling the depressive symptoms. Conclusions: These findings demonstrate that the presence of severe IN symptoms is an important factor related with dissociative tendency in AUD population with a history of physical abuse. PMID:29085089

Partial mediator role of physical abuse on the relationship between attention-deficit/hyperactivity disorder symptoms and severity of dissociative experiences in a sample of inpatients with alcohol use disorder.

PubMed

Evren, Cuneyt; Umut, Gokhan; Bozkurt, Muge; Can, Yesim; Evren, Bilge; Agachanli, Ruken

2017-01-01

This study aimed to evaluate the relationship of attention-deficit/hyperactivity disorder (ADHD) symptoms with dissociative experiences, and the mediator role of childhood traumas on this relationship, while controlling the effect of depression in alcohol use disorder (AUD). It was a hospital-based, cross-sectional study. One hundred and ninety inpatients with AUD were evaluated with the Beck Depression Inventory, the Adult ADHD Self-Report Scale (ASRS), Childhood Trauma Qestionnaire, and Dissociative Experiences Scale (DES). One-way ANOVA, Chi-squared test, and hierarchical linear regression model were performed. The ratio of those who receive 10 points or less from DES was 26.8%, those who receive points between 11 and 30 was 45.3%, and those who receive more than 30 points was 27.9%. The latter group that was considered as a group with high risk of dissociative disorder had higher scores from depression, childhood trauma, and ADHD scores than the other groups. Rate of those with high probability of ADHD was higher among this group. ASRS total score and inattentive subscale scores were moderately ( r = 0.552 and r = 0.547, respectively) and hyperactive/impulsive subscale was mildly ( r = 0.430) correlated with DES score. Severity of ADHD was related with the severity of dissociative symptoms, and physical abuse had partial mediator effect on this relationship, even after controlling the depressive symptoms. These findings demonstrate that the presence of severe IN symptoms is an important factor related with dissociative tendency in AUD population with a history of physical abuse.

Are major dissociative disorders characterized by a qualitatively different kind of dissociation?

PubMed

Rodewald, Frauke; Dell, Paul F; Wilhelm-Gossling, Claudia; Gast, Ursula

2011-01-01

A total of 66 patients with a major dissociative disorder, 54 patients with nondissociative disorders, and 30 nonclinical controls were administered the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised, the Dissociative Experiences Scale, the Multidimensional Inventory of Dissociation, and the Symptom Checklist 90-Revised. Dissociative patients reported significantly more dissociative and nondissociative symptoms than did nondissociative patients and nonclinical controls. When general psychopathology was controlled, the dissociation scores of dissociative patients were still significantly higher than those of both other groups, whereas the dissociation scores of nondissociative patients and nonclinical controls no longer differed. These findings appear to be congruent with a typological model of dissociation that distinguishes between 2 qualitatively different kinds of dissociation. Specifically, the results of this study suggest that the dissociation that occurs in major dissociative disorders (i.e., dissociative identity disorder [DID] and dissociative disorder not otherwise specified, Type 1 [DDNOS-1]) is qualitatively different from the dissociation that occurs in persons who do not have a dissociative disorder. In contrast to previous research, the dissociation of persons who do not have a dissociative disorder is not limited to absorption; it covers a much wider range of phenomena. The authors hypothesize that different mechanisms produce the dissociation of persons with DID and DDNOS-1 as opposed to the dissociation of persons who do not have a dissociative disorder.

Dissociative tendencies and facilitated emotional processing.

PubMed

Oathes, Desmond J; Ray, William J

2008-10-01

Dissociation is a process linked to lapses of attention, history of abuse or trauma, compromised emotional memory, and a disintegrated sense of self. It is theorized that dissociation stems from avoiding emotional information, especially negative emotion, to protect a fragile psyche. The present study tested whether or not dissociaters do actually avoid processing emotion by asking groups scoring high or low on the Dissociative Experiences Scale to judge the affective valence of several types of emotional stimuli. Manipulations of valence, modality (pictures or words), task complexity, and personal relevance lead to results suggesting that dissociation is linked to facilitated rather than deficient emotional processing. Our results are consistent with a theory that sensitivity to emotional material may be a contributing factor in subsequent dissociation to avoid further elaboration of upsetting emotion in these individuals. The findings for dissociation further exemplify the influence of individual differences in the link between cognition and emotion. (c) 2008 APA, all rights reserved

[Dissociative phenomena in a sample of outpatients].

PubMed

Cantone, Daniela; Sperandeo, Raffaele; Maldonato, Mauro Nelson; Cozzolino, Pasquale; Perris, Francesco

2012-01-01

The study describes the frequency and the quality of dissociative phenomena and their relationship with axis I disorders and the psychopathological severity in outpatients. The sample (N=383) was subjected to MINI diagnostic interview and self-assessment scales DES and SCL-90. The data were analysed using SPSS. The 11,0% of subjects has a score ≥20 on DES. The 5,2% has no dissociative symptoms. The absorption images is the most frequent dissociative phenomenon, the less common is the dissociation amnesia. A relationship between dissociative phenomena and conditions unemployment, marital separation and single parties and an inverse relationship with age founded. Dissociative phenomena are more frequent in participants who have been diagnosed at least one axis I disorder and their severity is positively correlated with the number of diagnosed diseases and scores to the General Symptomatic Index. Our results point towards the existence of three types of dissociative experiences. The first type, represented by the factor absorption/imaginative involvement, is expressed along a continuum from normal to pathological; a second type, represented by the factor depersonalization/derealization, occurs in a significantly more intense and specific among subjects with axis I disorders; the latest manifestation dissociative, described by the dissociation amnesia, seems to have a predominantly typological feature that qualifies it as an experience not commonly distributed in the general population. The identifying of dissociative symptoms is necessary for the psychopathologic evaluation and to improve the effectiveness of treatment programs.

Psychological impact on house staff of an initial versus subsequent emergency medicine rotation.

PubMed

Alagappan, K; Grlic, N; Steinberg, M; Pollack, S

2001-01-01

The objective of this study was to assess the psychological impact of a 4-week emergency medicine (EM) rotation on residents undergoing their first EM experience. These findings were compared to the psychological impact the rotation had on residents with prior EM experience. Data were obtained from a post hoc analysis of a previous study. Prerotation and postrotation psychological distress levels were assessed over a 4-week EM rotation. Anxiety and depressive symptoms were evaluated by the Brief Symptom Inventory and the Dissociative Experience Scale that together comprise a total of 14 psychometric scales. All scales were given at the beginning and end of the initial EM rotation for the academic year of 1994-1995. All information was coded and confidential. Eighteen junior residents (9/18 EM [50%]) were analyzed as a group and compared to 53 residents (34/51 EM [66%]) with prior exposure to the authors' emergency department. Residents doing their first EM rotation (N = 18) showed improvement in 13 of 14 scales (P = .002). Of the 13 scales that improved, 3 improved significantly: Brief Symptom Inventory = anxiety (P = .002) and Dissociative Experience Scale = absorption (P = .001) and other (P = .001). Residents with prior EM experience (N = 53) displayed worsening in 9 of 13 scales (P = not significant) and no change in 1. Residents undergoing their first EM rotation showed a significant decrease in psychological distress over the 4-week period. Residents with prior EM experience did not show a similar change.

The maladaptive personality traits of the Personality Inventory for DSM-5 (PID-5) in relation to the HEXACO personality factors and schizotypy/dissociation.

PubMed

Ashton, Michael C; Lee, Kibeom; de Vries, Reinout E; Hendrickse, Joshua; Born, Marise Ph

2012-10-01

The Personality Inventory for DSM-5 (PID-5), a new measure of maladaptive personality traits, has recently been developed by the DSM-5 Personality and Personality Disorders Workgroup. The PID-5 variables were examined within the seven-factor space defined by the six HEXACO factors and the Schizotypy/Dissociation factor (Ashton & Lee, 2012) using participant samples from Canada (N = 378) and the Netherlands (N = 476). Extension analyses showed that several PID-5 facet-level scales represented each of the Honesty-Humility, Emotionality, Extraversion, Conscientiousness, and Schizotypy/Dissociation factors. In contrast, only one PID-5 scale loaded strongly on HEXACO Agreeableness, and no PID-5 scales loaded strongly on Openness to Experience. In addition, a joint factor analysis involving the PID-5 variables and facets of the Five-Factor Model was conducted in the Canadian sample and recovered a set of seven factors corresponding rather closely to the HEXACO factors plus Schizotypy/Dissociation. The authors discuss implications for the assessment and structure of normal and abnormal personality.

Hypnotizability in acute stress disorder.

PubMed

Bryant, R A; Guthrie, R M; Moulds, M L

2001-04-01

This study investigated the relationship between acute dissociative reactions to trauma and hypnotizability. Acutely traumatized patients (N=61) with acute stress disorder, subclinical acute stress disorder (no dissociative symptoms), and no acute stress disorder were administered the Stanford Hypnotic Clinical Scale within 4 weeks of their trauma. Although patients with acute stress disorder and patients with subclinical acute stress disorder displayed comparable levels of nondissociative psychopathology, acute stress disorder patients had higher levels of hypnotizability and were more likely to display reversible posthypnotic amnesia than both patients with subclinical acute stress disorder and patients with no acute stress disorder. The findings may be interpreted in light of a diathesis-stress process mediating trauma-related dissociation. People who develop acute stress disorder in response to traumatic experience may have a stronger ability to experience dissociative phenomena than people who develop subclinical acute stress disorder or no acute stress disorder.

Evaluation of Relationship between Obsessive-compulsive Disorder and Dissociative Experiences

PubMed Central

Cetinkaya, Ozlem; Maner, Fulya

2018-01-01

Objective The aim of the study is to evaluate the relationship between obsessive-compulsive disorder (OCD) symptoms and dissociative experiences and the effect of childhood traumatic experiences on this relationship in OCD patients. Methods Fifty consecutive OCD patients and 50 healthy controls are enrolled for this study. Sociodemographic and Clinical Data Form, Dissociative Experiences Scale (DES), Padua Inventory (PI) and Childhood Trauma Questionnaire (CTQ) are applied to participants. Results Average DES total score in the patient group is 20.58 and in the control group it is 4.87. In the patient group, when we evaluate the relation strengths of DES total and subscale scores with PI total score, we found out that amnesia subscale has r=0.361 (p<0.01), absorption subscale has r=0.611 (p<0.01), depersonalization/derealization subscale has r=0.574 (p<0.01), and DES total score has r=0.55 (p<0.01) relation strengths with PI total score. In patient group both DES total score and CTQ total score have influence on PI total score independently from each other. In addition to this, the level of the influence of DES total scores on PI total scores is, R2=0.399 (p<0.01) and the level of the influence of CTQ total scores on PI total scores is R2=0.343 (p<0.01). Conclusion Dissociative experiences are seen more frequently in OCD patients than healthy controls. Among dissociative experiences, absorption has stronger relation with OCD symptoms. The relation between OCD and dissociation is independent from and stronger than the relation between childhood traumatic experiences and OCD. PMID:29739129

Validation of the factor structure of the adolescent dissociative experiences scale in a sample of trauma-exposed detained youth.

PubMed

Kerig, Patricia K; Charak, Ruby; Chaplo, Shannon D; Bennett, Diana C; Armour, Cherie; Modrowski, Crosby A; McGee, Andrew B

2016-09-01

The inclusion of a dissociative subtype in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–5 ) criteria for the diagnosis of posttraumatic stress disorder (PTSD) has highlighted the need for valid and reliable measures of dissociative symptoms across developmental periods. The Adolescent Dissociative Experiences Scale (A-DES) is 1 of the few measures validated for young persons, but previous studies have yielded inconsistent results regarding its factor structure. Further, research to date on the A-DES has been based upon nonclinical samples of youth or those without a known history of trauma. To address these gaps in the literature, the present study investigated the factor structure and construct validity of the A-DES in a sample of highly trauma-exposed youth involved in the juvenile justice system. A sample of 784 youth (73.7% boys) recruited from a detention center completed self-report measures of trauma exposure and the A-DES, a subset of whom (n = 212) also completed a measure of PTSD symptoms. Confirmatory factor analyses revealed a best fitting 3-factor structure comprised of depersonalization or derealization, amnesia, and loss of conscious control, with configural and metric invariance across gender. Logistic regression analyses indicated that the depersonalization or derealization factor effectively distinguished between those youth who did and did not likely meet criteria for a diagnosis of PTSD as well as those with PTSD who did and did not likely meet criteria for the dissociative subtype. These results provide support for the multidimensionality of the construct of posttraumatic dissociation and contribute to the understanding of the dissociative subtype of PTSD among adolescents. (PsycINFO Database Record PsycINFO Database Record (c) 2016 APA, all rights reserved

Personality features, dissociation, self-stigma, hope, and the complex treatment of depressive disorder

PubMed Central

Prasko, Jan; Ociskova, Marie; Grambal, Ales; Sigmundova, Zuzana; Kasalova, Petra; Marackova, Marketa; Holubova, Michaela; Vrbova, Kristyna; Latalova, Klara; Slepecky, Milos

2016-01-01

Objective Identifying the predictors of response to psychiatric and psychotherapeutic treatments may be useful for increasing treatment efficacy in pharmacoresistant depressive patients. The goal of this study was to examine the influence of dissociation, hope, personality trait, and selected demographic factors in treatment response of this group of patients. Methods Pharmacoresistant depressive inpatients were enrolled in the study. All patients completed Clinical Global Impression – both objective and subjective form (CGI), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) at baseline and after 6 weeks of combined pharmacotherapy and psychotherapy (group cognitive-behavioral or group psychodynamic) treatment as an outcome measures. The Internalized Stigma of Mental Illness Scale (ISMI), Dissociative Experience Scale (DES), Adult Dispositional Hope Scale (ADHS), and Temperament and Character Inventory (TCI-R) were completed at the start of the treatment with the intention to find the predictors of treatment efficacy. Results The study included 72 patients who were hospitalized for the pharmacoresistant major depression; 63 of them completed the study. The mean scores of BDI-II, BAI, subjCGI, and objCGI significantly decreased during the treatment. BDI-II relative change statistically significantly correlated with the total ISMI score, Discrimination Experience (ISMI subscale), and Harm Avoidance (TCI-R personality trait). According to stepwise regression, the strongest factors connected to BDI-II relative change were the duration of the disorder and Discrimination Experience (domain of ISMI). ObjCGI relative change significantly correlated with the level of dissociation (DES), the total ISMI score, hope in ADHS total score, and Self-Directedness (TCI-R). According to stepwise regression, the strongest factor connected to objCGI relative change was Discrimination Experience (domain of ISMI). The existence of comorbid personality disorder did not influence the treatment response. Conclusion According to the results of the present study, patients with pharmacoresistant depressive disorders, who have had more experience with discrimination because of their mental struggles, showed a poorer response to treatment. PMID:27785031

Dissociation in bipolar disorder: Relationships between clinical variables and childhood trauma.

PubMed

Hariri, Aytül Gursu; Gulec, Medine Yazici; Orengul, Fatma Fariha Cengiz; Sumbul, Esra Aydin; Elbay, Rumeysa Yeni; Gulec, Huseyin

2015-09-15

The dissociative experiences of patients with bipolar disorder (BD) differ from those of patients with other psychiatric disorders with regard to certain features. The primary goal of this study was to evaluate the relationship between the clinical variables of BD and childhood trauma using the factor structure, psychometric features, and potential subdimensions of the Dissociative Experience Scale (DES). This study included 200 BD patients who were in a remission period and 50 healthy volunteers. The BD patients were recruited from two psychiatry clinic departments in Turkey. The sociodemographic data of the two groups and their scores on the DES and Childhood Trauma Questionnaire (CTQ)-28 were compared. The overall DES scores and the scores for each DES item accurately and reliably measured dissociation in the BD patients (item-total correlation r scores: >0.20, Cronbach's alpha: 0.95), and a factor analysis revealed two subdimensions of the DES for BD: identity confusion/alteration (SubDES-1) and amnesia and depersonalization/derealization (SubDES-2). Although age at onset of BD was significantly correlated with both subdimensions, illness duration was significantly correlated only with the SubDES-2. Of all the subjects, 19.5% (39/200 patients) were identified as having dissociative experiences by the DES-Taxon (DES-T), and subjects in this subscale (DES-T-positive) had significantly higher total scores on the CTQ-28 as well as higher scores on each subgroup of this scale. The highest CTQ-28 subgroup score was emotional neglect, which was followed by emotional abuse and physical neglect and then sexual abuse and physical abuse. There was a significant correlation between total scores on the CTQ-28 and SubDES-2 but none of the CTQ-28 subscale scores was significantly correlated with either SubDES-1 or SubDES-2. The DES sufficiently and reliably identified the experience of dissociative symptoms on the part of BD patients, and a factor analysis revealed two subdimensions of BD on this scale. In particular, DES-T-positive subjects experienced a greater amount of childhood trauma and, as a result, had an earlier age at onset of BD. Additionally, SubDES-2, which was associated with amnesia and depersonalization/derealization, was closely related to illness duration. Copyright © 2015 Elsevier B.V. All rights reserved.

Alexithymia: its prevalence and correlates in a British undergraduate sample.

PubMed

Mason, O; Tyson, M; Jones, C; Potts, S

2005-03-01

Alexithymia is characterized by a difficulty identifying and describing emotional states, as well as an externally oriented thinking style. This study investigated the prevalence of alexithymia in a British undergraduate sample and assesses its relationship to both parental bonding and dissociation. The Toronto alexithymia scale (TAS-20), the Parental Bonding Instrument (PBI), and the Dissociative Experience Scale (DES) were administered to a sample of 181 male and 190 female undergraduate students from both arts and science subjects. Rates of alexithymia were comparable with those observed in some other countries. Contrary to predictions, females were found to have higher rates than males, and the highest presence of alexithymia was in female science students. As in previous studies, alexithymia was linked to both dissociation and perceptions of a lack of maternal care, though the degree of association to the latter was small. Dissociative experiences were predicted by both maternal overprotection and difficulties identifying feelings. Some qualified support was found for the relevance of early maternal bonding to later difficulties processing emotions. The presence of greater alexithymia in females, and female science students in particular, was discussed in reference to similar observations elsewhere. There was also an understandable relationship between 'difficulty identifying feelings' (TAS) and both depersonalization/derealization and absorption (DES).

Is the dissociative adult suggestible? A test of the trauma and fantasy models of dissociation.

PubMed

Kluemper, Nicole S; Dalenberg, Constance

2014-01-01

Psychologists have long assumed a connection between traumatic experience and psychological dissociation. This hypothesis is referred to as the trauma model of dissociation. In the past decade, a series of papers have been published that question this traditional causal link, proposing an alternative fantasy model of dissociation. In the present research, the relationship among dissociation, suggestibility, and fantasy proneness was examined. Suggestibility was measured through the Gudjonsson Scale of Interrogative Suggestibility (GSS) as well as an autobiographically based version of this measure based on the events of September 11, 2001. Consistent with prior research and with the trauma model, dissociation correlated positively with trauma severity (r = .32, p < .01) and fantasy proneness (r = .60, p < .01). Inconsistent with the fantasy model, dissociation did not correlate with the neutral form of the GSS and correlated negatively (r = -.24, p < .05) with the trauma-focused form of this suggestibility measure. Although some participants did become quite emotional during the procedure, the risk/benefit ratio was perceived by almost all participants to be positive, with more reactive individuals evaluating the procedure more positively. The results consistently support the trauma model of dissociation and fail to support the fantasy model of dissociation.

Reliability and validity of the Turkish version of the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D): a preliminary study.

PubMed

Kundakçi, Turgut; Sar, Vedat; Kiziltan, Emre; Yargiç, Ilhan L; Tutkun, Hamdi

2014-01-01

A total of 34 consecutive patients with dissociative identity disorder or dissociative disorder not otherwise specified were evaluated using the Turkish version of the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D). They were compared with a matched control group composed of 34 patients who had a nondissociative psychiatric disorder. Interrater reliability was evaluated by 3 clinicians who assessed videotaped interviews conducted with 5 dissociative and 5 nondissociative patients. All subjects who were previously diagnosed by clinicians as having a dissociative disorder were identified as positive, and all subjects who were previously diagnosed as not having a dissociative disorder were identified as negative. The scores of the main symptom clusters and the total score of the SCID-D differentiated dissociative patients from the nondissociative group. There were strong correlations between the SCID-D and the Dissociative Experiences Scale total and subscale scores. These results are promising for the validity and reliability of the Turkish version of the SCID-D. However, as the present study was conducted on a predominantly female sample with very severe dissociation, these findings should not be generalized to male patients, to dissociative disorders other than dissociative identity disorder, or to broader clinical or nonclinical populations.

Dissociative Disorders Among Chinese Inpatients Diagnosed With Schizophrenia

PubMed Central

Yu, Junhan; Ross, Colin A.; Keyes, Benjamin B.; Li, Ying; Dai, Yunfei; Zhang, Tianhong; Wang, Lanlan; Fan, Qing; Xiao, Zeping

2010-01-01

The purpose of the study was to assess the prevalence of dissociative disorders in a sample of Chinese psychiatric inpatients. Participants in the study consisted of 569 consecutively admitted inpatients at Shanghai Mental Health Center, China, of whom 84.9% had a clinical diagnosis of schizophrenia based on the Chinese Classification and Diagnostic Criteria for Mental Disorders, Version 3 (CCMD-3). All participants completed a self-report measure of dissociation, the Dissociative Experiences Scale (DES) and none had a prior diagnosis of a dissociative disorder. Ninety-six randomly selected participants were interviewed with a structured interview, the Dissociative Disorders Interview Schedule (DDIS) and a clinical interview. These 96 patients did not differ significantly from the 473 patients who were not interviewed on any demographic measures or on the self-report measure dissociation. A total of 28 (15.3%, after weighting of the data) patients received a clinical diagnosis of a dissociative disorder based on DSM-IV-TR criteria. Dissociative identity disorder was diagnosed in 2 (0.53%, after weighting) patients. Compared to the patients without a dissociative disorder, patients with dissociative disorders were significantly more likely to report childhood abuse (57.1% versus 22.1%), but the two groups did not differ significantly on any demographic measures. Dissociative disorders were readily identified in an inpatient psychiatric population in China. PMID:20603768

Validity of CBCL-derived PTSD and dissociation scales: further evidence in a sample of neglected children and adolescents.

PubMed

Milot, Tristan; Plamondon, André; Ethier, Louise S; Lemelin, Jean-Pascal; St-Laurent, Diane; Rousseau, Michel

2013-05-01

There is growing evidence that child neglect is an important risk factor for posttraumatic stress disorder (PTSD) and dissociation. Considering that the Child Behavior Checklist (CBCL) is a widely used measure, the possibility of using validated CBCL-derived trauma symptoms scales could be particularly useful to better understand how trauma symptoms develop among neglected children and adolescents. This study examined the factor structure of three CBCL-derived measures of PTSD and dissociation (namely, PTSD scale, Dissociation scale, and PTSD/Dissociation scale) in a sample of 239 neglected children and adolescents aged 6 to 18 years using the latest version of CBCL (CBCL 6-18). Evidence of convergent validity of these scales was also examined for participants aged 12 and under using two well-validated measures of PTSD and Dissociation: the Trauma Symptoms Checklist for Young Children and the Child Dissociation Checklist. Findings suggest that CBCL-derived measures of trauma symptoms, especially PTSD and Dissociations scales, may be of heuristic value in the study of trauma symptomatology in neglected samples. Factor structure and evidence of convergent validity were supported for these two scales. Results also provide further support to the well-established assumption that PTSD and dissociation are two related but different constructs.

Emotional Closeness with Perpetrators and Amnesia for Child Sexual Abuse

ERIC Educational Resources Information Center

Schultz, Tammy; Passmore, J. Lawrence; Yoder, C. Y.

2003-01-01

Over the past decade, a contentious debate regarding delayed memories of childhood sexual abuse (CSA) has existed. In order to address this debate, 240 female participants completed questions about CSA, the Dissociative Experience Scale (Bernstein & Putnam, 1986), Perceived Emotional Closeness with Perpetrator Scale (Schultz, Passmore, &…

Self-mutilating behavior in patients with dissociative disorders: the role of innate hypnotic capacity.

PubMed

Ebrinc, Servet; Semiz, Umit B; Basoglu, Cengiz; Cetin, Mesut; Agargun, Mehmet Y; Algul, Ayhan; Ates, Alpay

2008-01-01

Despite the fact that the assumption of a relationship between self-mutilation and dissociative disorders (DD) has a long history, there is little empirical evidence to support this premise. The present study examined this relationship and investigated whether this commonality is associated with innate hypnotic capacity. Fifty patients diagnosed with DD and 50 control subjects with major depression were assessed by using a self-mutilation questionnaire, Dissociative Experiences Scale, Traumatic Experiences Checklist, and the Eye-Roll Sign for their self-mutilating behaviors, dissociative symptoms, early trauma, and innate hypnotic capacity, respectively. We have found that 82% of the present sample of patients with DD injured themselves. They had higher scores on trauma, dissociation and eye-roll measurements than controls. In addition, DD patients with self-mutilation were more likely to have high scores of trauma, dissociation and eye-roll than those without self-mutilation. Innate hypnotic capacity was a strong predictor of self-mutilating behavior in DD patients. This study strongly supports the assumption that patients with DD are at high risk for self-mutilating behavior and points to the necessity of routine screening for self-mutilating behavior as well as the hypnotic capacity which may constitute a high risk for self-injury in this patient group.

Cognition and belief in paranormal phenomena: gestalt/feature-intensive processing theory and tendencies toward ADHD, depression, and dissociation.

PubMed

Sharps, Matthew J; Matthews, Justin; Asten, Janet

2006-11-01

Belief in paranormal phenomena and cryptids--unknown animals such as Bigfoot--may predispose individuals to interpret real-world objects and events in the same way that eyewitness identification can be biased by unrelated information (P. James and N. Thorpe, 1999). Psychological tendencies toward attention deficit hyperactivity disorder (ADHD), dissociation, and depression, even at subclinical levels, may be associated systematically with particular paranormal or cryptozoological beliefs. The authors evaluated these psychological tendencies using the Conners Adult ADHD Rating Scales (C. K. Conners, D. Erhardt, and E. Sparrow, 1999), the Dissociative Experiences Scale (L. Coleman & J. Clark, 1999), and the Beck Depression Inventory-II (A. T. Beck, 1996). They performed regression analyses against beliefs in ghosts, unidentified flying objects (UFOs), extrasensory perception (ESP), astrology, and cryptids. ADHD, dissociation, and depression were associated with enhanced tendencies toward paranormal and cryptozoological beliefs, although participants who believed in each of the phenomena differed from one another in predictable and psychologically distinguishable ways. Cognitively biasing influences of preexisting psychological tendencies may predispose individuals to specific perceptual and cognitive errors during confrontation of real-world phenomena.

Peritraumatic dissociation, acute stress, and early posttraumatic stress disorder in victims of general crime.

PubMed

Birmes, P; Carreras, D; Ducassé, J L; Charlet, J P; Warner, B A; Lauque, D; Schmitt, L

2001-09-01

To compare the relation between peritraumatic dissociation and acute stress and the early development of posttraumatic stress disorder (PTSD) in victims of general crime. A total of 48 subjects were assessed within 24 hours of the trauma, using the Peritraumatic Dissociative Experiences Questionnaire Self-Report Version (PDEQ-SRV). They were followed longitudinally to assess acute stress (2 weeks after the assault,) using the Standford Acute Stress Reaction Questionnaire (SASRQ), and posttraumatic stress (at 5 weeks), using the Clinician-Administered PTSD Scale (CAPS) and the Impact of Event Scale (IES). Among PTSD subjects mean PDEQ scores were significantly higher (mean 3, SD 0.9) than in those without PTSD (mean 2.3, SD 0.7) (t = 2.78, df 46, P = 0.007). Among PTSD subjects, mean SASRQ scores were significantly higher (mean 97.9, SD 29.2) than in those without PTSD (mean 54.8, SD 28.2) (t = 4.9, df 46, P = 0.00007). High levels of peritraumatic dissociation and acute stress following violent assault are risk factors for early PTSD. Identifying acute reexperiencing can help the clinician identify subjects at highest risk.

Dissociation of Laboratory-Synthesized Methane Hydrate in Coarse-Grained Sediments by Slow Depressurization

NASA Astrophysics Data System (ADS)

Phillips, S. C.; You, K.; Borgfeldt, T.; Meyer, D.; Dong, T.; Flemings, P. B.

2016-12-01

We performed four dissociation experiments in which experimentally-formed methane hydrate was dissociated via slow, stepwise depressurization, revealing in situ salinity conditions. Overall, these results suggest the occurrence of local pore water freshening around dissociating hydrate in which bulk equilibrium behavior is limited by salt diffusion. Depressurization was performed at a constant confining temperature over 1 to 3 weeks by releasing small volumes of methane gas from the top of a vertically-oriented sample into an inverted graduated cylinder. We identify three distinct regimes of depressurization based on pressure drop behavior: (1) release of free gas down to initial hydrate dissociation at 3.3 MPa in NaBr or 4.64 MPa in NaCl, (2) dissociation of methane hydrate characterized by a slow, logarithmic increase in pressure after each gas release and (3) residual free gas release. Initial hydrate dissociation in NaCl brine at 4.64 MPa corresponds to the phase boundary for hydrate in 9.6 wt% NaCl. In the NaCl experiment, pressure increases of 0.16 MPa while the sample was shut in over 3 days likely correspond to a recovery in salinity of 0.7 wt. %. Salt ions likely diffuse from brine ahead of the hydrate front, based on a length scale for diffusion of NaCl of 6.3 cm for 3 days. In this experiment dissociation at bulk equilibrium is expected to decline from 4.54 to 4.04 MPa; however actual dissociation during 73 gas releases over 15 days, results in a pressure drop from 4.64 to 3.25 MPa. Hydrate samples were formed by injection of methane gas at 1 ºC and 12.24 MPa within a cylinder packed with medium-grained quartz sand and initially saturated in a 7 wt% NaBr or NaCl solution. In two experiments in which the system was thoroughly leak tested, total methane consumed during formation and recovered during depressurization match within 7% indicating this approach to be relatively accurate for determining total methane in experimental or pressure core samples.

Dissociative disorders among Chinese inpatients diagnosed with schizophrenia.

PubMed

Yu, Junhan; Ross, Colin A; Keyes, Benjamin B; Li, Ying; Dai, Yunfei; Zhang, Tianhong; Wang, Lanlan; Fan, Qing; Xiao, Zeping

2010-01-01

The purpose of this study was to assess the prevalence of dissociative disorders in a sample of Chinese psychiatric inpatients. Participants in the study were 569 consecutively admitted inpatients at Shanghai Mental Health Center, China, of whom 84.9% had a clinical diagnosis of schizophrenia based on the Chinese Classification and Diagnostic Criteria of Mental Disorders, Version 3. All participants completed a self-report measure of dissociation (the Dissociative Experiences Scale), and none had a prior diagnosis of a dissociative disorder. A total of 96 randomly selected participants were interviewed with a structured interview (the Dissociative Disorders Interview Schedule) and a clinical interview. These 96 patients did not differ significantly from the 473 patients who were not interviewed on any demographic measures or who did not complete the self-report dissociation measure. A total of 28 patients (15.3%, after weighting of the data) received a clinical diagnosis of a dissociative disorder based on Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.) criteria. Dissociative identity disorder was diagnosed in 2 patients (0.53%, after weighting). Compared to the patients without a dissociative disorder, patients with dissociative disorders were significantly more likely to report childhood abuse (57.1% vs. 22.1%), but the 2 groups did not differ significantly on any demographic measures. Dissociative disorders were readily identified in an inpatient psychiatric population in China.

Dissociation in victims of childhood abuse or neglect: a meta-analytic review.

PubMed

Vonderlin, Ruben; Kleindienst, Nikolaus; Alpers, Georg W; Bohus, Martin; Lyssenko, Lisa; Schmahl, Christian

2018-04-10

Childhood abuse and neglect are associated with dissociative symptoms in adulthood. However, empirical studies show heterogeneous results depending on the type of childhood abuse or neglect and other maltreatment characteristics. In this meta-analysis, we systematically investigated the relationship between childhood interpersonal maltreatment and dissociation in 65 studies with 7352 abused or neglected individuals using the Dissociative Experience Scale (DES). We extracted DES-scores for abused and non-abused populations as well as information about type of abuse/neglect, age of onset, duration of abuse, and relationship to the perpetrator. Random-effects models were used for data synthesis, and meta-regression was used to predict DES-scores in abused populations from maltreatment characteristics. The results revealed higher dissociation in victims of childhood abuse and neglect compared with non-abused or neglected subsamples sharing relevant population features (MAbuse = 23.5, MNeglect = 18.8, MControl = 13.8) with highest scores for sexual and physical abuse. An earlier age of onset, a longer duration of abuse, and parental abuse significantly predicted higher dissociation scores. This meta-analysis underlines the importance of childhood abuse/neglect in the etiology of dissociation. The identified moderators may inform risk assessment and early intervention to prevent the development of dissociative symptoms.

Effects of Psychiatric Symptoms on Attention in North Korean Refugees.

PubMed

Lee, Yu Jin; Jun, Jin Yong; Park, Juhyun; Kim, Soohyun; Gwak, Ah Reum; Lee, So Hee; Yoo, So Young; Kim, Seog Ju

2016-09-01

We investigated the performance of North Korean refugees on attention tasks, and the relationship between that performance and psychiatric symptoms. Sustained and divided attention was assessed using the computerized Comprehensive Attention Test in North Korean refugees and in South Koreans. All participants also completed the Beck Depression Inventory, the Beck Anxiety Inventory, the Impact of Event Scale-Revised and the Dissociative Experiences Scale-II (DES-II). The North Korean refugees showed slower reaction times (RTs) on the visual sustained attention task compared to the South Koreans after controlling for age and sex. North Korean refugees had a greater number of omission errors (OEs) on the divided attention task and a higher standard deviation (SD) of RT. Total DES-II scores of the North Korean refugees were associated with the number of OEs and the SD of RT on the sustained attention task, and with the number of OEs on the divided attention task. North Korean refugees showed poorer performance on computerized attention tasks. In addition, attention deficit among North Korean refugees was associated with their dissociative experiences. Our results suggest that refugees may have attention deficits, which may be related to their psychiatric symptoms, particularly dissociation.

A Non-linear Predictive Model of Borderline Personality Disorder Based on Multilayer Perceptron.

PubMed

Maldonato, Nelson M; Sperandeo, Raffaele; Moretto, Enrico; Dell'Orco, Silvia

2018-01-01

Borderline Personality Disorder is a serious mental disease, classified in Cluster B of DSM IV-TR personality disorders. People with this syndrome presents an anamnesis of traumatic experiences and shows dissociative symptoms. Since not all subjects who have been victims of trauma develop a Borderline Personality Disorder, the emergence of this serious disease seems to have the fragility of character as a predisposing condition. Infect, numerous studies show that subjects positive for diagnosis of Borderline Personality Disorder had scores extremely high or extremely low to some temperamental dimensions (harm Avoidance and reward dependence) and character dimensions (cooperativeness and self directedness). In a sample of 602 subjects, who have had consecutive access to an Outpatient Mental Health Service, it was evaluated the presence of Borderline Personality Disorder using the semi-structured interview for the DSM IV-TR personality disorders. In this population we assessed the presence of dissociative symptoms with the Dissociative Experiences Scale and the personality traits with the Temperament and Character Inventory developed by Cloninger. To assess the weight and the predictive value of these psychopathological dimensions in relation to the Borderline Personality Disorder diagnosis, a neural network statistical model called "multilayer perceptron," was implemented. This model was developed with a dichotomous dependent variable, consisting in the presence or absence of the diagnosis of borderline personality disorder and with five covariates. The first one is the taxonomic subscale of dissociative experience scale, the others are temperamental and characterial traits: Novelty-Seeking, Harm-Avoidance, Self-Directedness and Cooperativeness. The statistical model, that results satisfactory, showed a significance capacity (89%) to predict the presence of borderline personality disorder. Furthermore, the dissociative symptoms seem to have a greater influence than the character traits in the borderline personality disorder e disease. In conclusion, the results seem to indicate that to borderline personality disorder development, contribute both psychic factors, such as temperament and character traits, and environmental factors, such as traumatic events capable of producing dissociative symptoms. These factors interact in a nonlinear way in producing maladaptive behaviors typical of this disorder.

Cyclic formation and dissociation of methane hydrate within partially water saturated sand

NASA Astrophysics Data System (ADS)

Kneafsey, T. J.; Nakagawa, S.

2010-12-01

For partially water-saturated sediments, laboratory experiments have shown that methane hydrate forms heterogeneously within a sample at the core scale. The heterogeneous distribution of hydrate in combination with grain-scale hydrate location (eg. grain cementing, load bearing, and pore filling), determines the overall mechanical properties of hydrate-bearing sediments including shear strength and seismic properties. For this reason, understanding the heterogeneity of hydrate-bearing sample is essential when the bulk properties of the sample are examined in the laboratory. We present a series of laboratory methane hydrate formation and dissociation experiments with concurrent x-ray CT imaging and low-frequency (near 1 kHz) seismic measurements. The seismic measurements were conducted using a new acoustic resonant bar technique called the Split Hopkinson Resonant Bar method, which allows using a small sediment core (3.75 cm diameter, 7.5 cm length). The experiment was conducted using a jacketed, pre-compacted, fine-grain silica sand sample with a 40% distilled water saturation. Under isotropic confining stress of 6.9 MPa and a temperature 4 oC, the hydrate was formed in the sample by injecting pure methane gas at 5.6 MPa. Once the hydrate formed, it was dissociated by reducing the pore pressure to 2.8 MPa. This cycle was repeated by three times (dissociation test for the third cycle was not done) to examine the resulting changes in the hydrate distribution and seismic signatures. The repeated formation of hydrate resulted in significant changes in its distribution, which resulted in differences in the overall elastic properties of the sample, determined from the seismic measurements. Interestingly, the time intervals between the dissociation and subsequent formation of hydrate affected the rate of hydrate formation, shorter intervals resulting in faster formation. This memory effect, possibly caused by the presence of residual “seed crystals” in the pore water providing nucleation points for hydrate formation, did not result in rapid formation at all locations in the sample. In spite of heterogeneity, observed seismic properties were very similar for the two measurements during dissociation.

EEG and chaos: Description of underlying dynamics and its relation to dissociative states

NASA Technical Reports Server (NTRS)

Ray, William J.

1994-01-01

The goal of this work is the identification of states especially as related to the process of error production and lapses of awareness as might be experienced during aviation. Given the need for further articulation of the characteristics of 'error prone state' or 'hazardous state of awareness,' this NASA grant focused on basic ground work for the study of the psychophysiology of these states. In specific, the purpose of this grant was to establish the necessary methodology for addressing three broad questions. The first is how the error prone state should be conceptualized, and whether it is similar to a dissociative state, a hypnotic state, or absent mindedness. Over 1200 subjects completed a variety of psychometric measures reflecting internal states and proneness to mental lapses and absent mindedness; the study suggests that there exists a consistency of patterns displayed by individuals who self-report dissociative experiences such that those individuals who score high on measures of dissociation also score high on measures of absent mindedness, errors, and absorption, but not on scales of hypnotizability. The second broad question is whether some individuals are more prone to enter these states than others. A study of 14 young adults who scored either high or low on the dissociation experiences scale performed a series of six tasks. This study suggests that high and low dissociative individuals arrive at the experiment in similar electrocortical states and perform cognitive tasks (e.g., mental math) in a similar manner; it is in the processing of internal emotional states that differences begin to emerge. The third question to be answered is whether recent research in nonlinear dynamics, i.e., chaos, offer an addition and/or alternative to traditional signal processing methods, i.e., fast Fourier transforms, and whether chaos procedures can be modified to offer additional information useful in identifying brain states. A preliminary review suggests that current nonlinear dynamical techniques such as dimensional analysis can be successfully applied to electrocortical activity. Using the data set developed in the study of the young adults, chaos analyses using the Farmer algorithm were performed; it is concluded that dimensionality measures reflect information not contained in traditional EEG Fourier analysis.

Dissociative absorption: An empirically unique, clinically relevant, dissociative factor.

PubMed

Soffer-Dudek, Nirit; Lassri, Dana; Soffer-Dudek, Nir; Shahar, Golan

2015-11-01

Research of dissociative absorption has raised two questions: (a) Is absorption a unique dissociative factor within a three-factor structure, or a part of one general dissociative factor? Even when three factors are found, the specificity of the absorption factor is questionable. (b) Is absorption implicated in psychopathology? Although commonly viewed as "non-clinical" dissociation, absorption was recently hypothesized to be specifically associated with obsessive-compulsive symptoms. To address these questions, we conducted exploratory and confirmatory factor analyses on 679 undergraduates. Analyses supported the three-factor model, and a "purified" absorption scale was extracted from the original inclusive absorption factor. The purified scale predicted several psychopathology scales. As hypothesized, absorption was a stronger predictor of obsessive-compulsive symptoms than of general psychopathology. In addition, absorption was the only dissociative scale that longitudinally predicted obsessive-compulsive symptoms. We conclude that absorption is a unique and clinically relevant dissociative tendency that is particularly meaningful to obsessive-compulsive symptoms. Copyright © 2015 Elsevier Inc. All rights reserved.

Photodissociation dynamics of nitromethane at 226 and 271 nm at both nanosecond and femtosecond time scales.

PubMed

Guo, Y Q; Bhattacharya, A; Bernstein, E R

2009-01-08

Photodissociation of nitromethane has been investigated for decades both theoretically and experimentally; however, as a whole picture, the dissociation dynamics for nitromethane are still not clear, although many different mechanisms have been proposed. To make a complete interpretation of these different mechanisms, photolysis of nitromethane at 226 and 271 nm under both collisional and collisionless conditions is investigated at nanosecond and femtosecond time scales. These two laser wavelengths correspond to the pi* <-- pi and pi* <-- n excitations of nitromethane, respectively. In nanosecond 226 nm (pi* <-- pi) photolysis experiments, CH(3) and NO radicals are observed as major products employing resonance enhanced multiphoton ionization techniques and time-of-flight mass spectrometry. Additionally, OH and CH(3)O radicals are weakly observed as dissociation products employing laser induced fluorescence spectroscopy; the CH(3)O product is only observed under collisional conditions. In femtosecond 226 nm experiments, CH(3), NO(2), and NO products are observed. These results confirm that rupture of C-N bond should be the main primary process for the photolysis of nitromethane after the pi* <-- pi excitation at 226 nm, and the NO(2) molecule should be the precursor of the observed NO product. Formation of the CH(3)O radical after the recombination of CH(3) and NO(2) species under collisional conditions rules out a nitro-nitrite isomerization mechanism for the generation of CH(3)O and NO from pi pi* CH(3)NO(2). The OH radical formation for pi pi* CH(3)NO(2) should be a minor dissociation channel because of the weak OH signal in both nanosecond and femtosecond (nonobservable) experiments. Single color femtosecond pump-probe experiments at 226 nm are also employed to monitor the dynamics of the dissociation of nitromethane after the pi* <-- pi excitation. Because of the ultrafast dynamics of product formation at 226 nm, the pump-probe transients for the three dissociation products are measured as an autocorrelation of the laser pulse, indicating the dissociation of nitromethane in the pi pi* excited state is faster than the laser pulse duration (180 fs). In nanosecond 271 nm (pi* <-- n) photolysis experiments, pump-probe experiments are performed to detect potential dissociation products, such as CH(3), NO(2), CH(3)O, and OH; however, none of them is observed. In femtosecond 271 nm laser experiments, the nitromethane parent ion is observed with major intensity, together with CH(3), NO(2), and NO fragment ions with only minor intensities. Pump-probe transients for both nitromethane parent and fragment ions at 271 nm excitation and 406.5 nm ionization display a fast exponential decay with a constant time of 36 fs, which we suggest to be the lifetime of the excited n pi* state of nitromethane. Combined with the 271 nm nanosecond pump-probe experiments, in which none of the CH(3), NO(2), CH(3)O, or OH fragment is observed, we suggest that all the fragment ions generated in 271 nm femtosecond laser experiments are derived from the parent ion, and dissociation of nitromethane from the n pi* excited electronic state does not occur in a supersonic molecular beam under collisionless conditions.

Factor structure and reliability of the Spanish version of the Dissociative Ability Scale.

PubMed

Pérez-Fabello, María José; Campos, Alfredo

2017-01-01

Everybody has dissociative ability to some extent, though this may vary from one individual to another. Several tests have been designed to measure dissociative ability, such as the Dissociative Ability Scale (Fisher, Johnson, & Elkins, 2013). Thus, the aim of this study was to assess the reliability and validity of the Spanish version of this test in a sample of 204 undergraduates seeking a fine arts degree at the University of Vigo (Spain). The reliability and validity of the Dissociative Ability Scale was found to be satisfactory for measuring dissociative ability. The results are discussed and innovative lines of research are proposed.

The role of depression and dissociation in the link between childhood sexual abuse and later parental practices.

PubMed

Collin-Vézina, Delphine; Cyr, Mireille; Pauzé, Robert; McDuff, Pierre

2005-01-01

Research has yielded contradictory results on the relationship between childhood sexual abuse and later parental functioning. This study was undertaken to specify the link between childhood sexual abuse and maternal parenting, while taking into account mothers' childhood physical and emotional traumas and current depressive and dissociative symptoms. Data were collected through self-report measures completed by 93 French-speaking Canadian mothers of children aged 6 to 11 years referred to Youth Protection Services. Parental behaviors examined included involvement with the child, use of positive reinforcement, lack of monitoring and supervision of the child, inconsistency in applying discipline, and use of corporal punishment. Mothers' perception of the quality of the relationship with her child was also assessed. In addition, history of abuse and neglect, depression and dissociation were respectively measured with the Childhood Trauma Questionnaire, the Diagnostic Interview Schedule Simplified, and the Dissociative Experiences Scale. The short-form of the Marlowe-Crowne Social Desirability Scale was used to control for respondent bias aimed at minimizing their problems. Mothers' current depressive symptoms were not found to predict any of the parental dimensions measured. Results from multiple hierarchical regressions pointed to dissociative symptoms as the key predictor of parental practices and attitudes. More specifically, dissociative symptoms predicted the use of positive reinforcement, lack of monitoring and supervision of the child, inconsistency in applying discipline, and use of corporal punishment. Dissociation also mediated the association between childhood maltreatment (physical and emotional abuse and neglect) and inconsistency in applying discipline. Implications for research and practice are discussed.

The severity of Internet addiction risk and its relationship with the severity of borderline personality features, childhood traumas, dissociative experiences, depression and anxiety symptoms among Turkish university students.

PubMed

Dalbudak, Ercan; Evren, Cuneyt; Aldemir, Secil; Evren, Bilge

2014-11-30

The aim of this study was to investigate the relationship of Internet addiction (IA) risk with the severity of borderline personality features, childhood traumas, dissociative experiences, depression and anxiety symptoms among Turkish university students. A total of 271 Turkish university students participated in this study. The students were assessed through the Internet Addiction Scale (IAS), the Borderline Personality Inventory (BPI), the Dissociative Experiences Scale (DES), the Childhood Trauma Questionnaire (CTQ-28), the Beck Depression Inventory (BDI) and the Beck Anxiety Inventory (BAI). The rates of students were 19.9% (n=54) in the high IA risk group, 38.7% (n=105) in the mild IA risk group and 41.3% (n=112) in the group without IA risk. Correlation analyses revealed that the severity of IA risk was related with BPI, DES, emotional abuse, CTQ-28, depression and anxiety scores. Univariate covariance analysis (ANCOVA) indicated that the severity of borderline personality features, emotional abuse, depression and anxiety symptoms were the predictors of IAS score, while gender had no effect on IAS score. Among childhood trauma types, emotional abuse seems to be the main predictor of IA risk severity. Borderline personality features predicted the severity of IA risk together with emotional abuse, depression and anxiety symptoms among Turkish university students. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Psychiatric comorbidity in patients with conversion disorder and prevalence of dissociative symptoms.

PubMed

Yayla, Sinan; Bakım, Bahadır; Tankaya, Onur; Ozer, Omer Akil; Karamustafalioglu, Oguz; Ertekin, Hulya; Tekin, Atilla

2015-01-01

The 1st objective of the current study was to investigate the frequency and types of dissociative symptoms in patients with conversion disorder (CD). The 2nd objective of the current study was to determine psychiatric comorbidity in patients with and without dissociative symptoms. A total of 54 consecutive consenting patients primarily diagnosed with CD according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, criteria who were admitted to the psychiatric emergency outpatient clinic of Sisli Etfal Research and Teaching Hospital (Istanbul, Turkey) were included in the study. The Structured Clinical Interview for DSM-IV Axis I Disorders, Structured Interview for DSM-IV Dissociative Disorders, and Dissociative Experiences Scale were administered. Study groups consisted of 20 patients with a dissociative disorder and 34 patients without a diagnosis of any dissociative disorder. A total of 37% of patients with CD had any dissociative diagnosis. The prevalence of dissociative disorders was as follows: 18.5% dissociative disorder not otherwise specified, 14.8% dissociative amnesia, and 3.7% depersonalization disorder. Significant differences were found between the study groups with respect to comorbidity of bipolar disorder, past hypomania, and current and past posttraumatic stress disorder (ps = .001, .028, .015, and .028, respectively). Overall comorbidity of bipolar disorder was 27.8%. Psychiatric comorbidity was higher and age at onset was earlier among dissociative patients compared to patients without dissociative symptoms. The increased psychiatric comorbidity and early onset of conversion disorder found in patients with dissociative symptoms suggest that these patients may have had a more severe form of conversion disorder.

Temperament and character traits in patients with conversion disorder and their relations with dissociation.

PubMed

Sarisoy, Gökhan; Kaçar, Ö Mer Faruk; Öztürk, Arif; Yilman, Tuba; Mor, Sema; Özturan, Deniz Deniz; Yazici, Neslihan; Gümüş, Kübra

2015-12-01

The purpose of this study was to investigate temperament and character traits in patients with conversion disorder and the relation of these traits with dissociative symptoms. Sixty patients (60) diagnosed with conversion disorder according to DSM-IV-TR and 60 healthy volunteers were included in the study. All participants' temperament and character traits were determined using Cloninger's Temperament and Character Inventory (TCI). Patients with conversion disorder were divided into two subgroups using the Dissociative Experiences Scale (DES), dissociative (n=30, 50%) and non-dissociative (n=30, 50%). The two conversion disorder subgroups were compared with the control group in terms of temperament and character traits. Correlation analysis was also performed between TCI and DES scores in the entire conversion group. Novelty seeking (NS) scores were lower in both the dissociative and non-dissociative groups compared to the control group. Harm avoidance (HA) scores were higher in the dissociative group than in the control group. Reward dependence (RD) scores were lower in the dissociative group than in the non-dissociative and control group. Self-directedness (SD) scores were lower in the dissociative group than in the control group. Self-transcendence (ST) scores were higher in the dissociative group than in the non-dissociative group. DES scores were negatively correlated with RD and SD scores in the entire conversion group and positively correlated with ST scores. Low NS temperament traits may be associated with conversion disorder. High HA and low RD temperament traits and low SD and high ST character traits may be associated with pathological dissociation in patients with conversion disorder.

The relationship of psychological trauma with trichotillomania and skin picking.

PubMed

Özten, Eylem; Sayar, Gökben Hızlı; Eryılmaz, Gül; Kağan, Gaye; Işık, Sibel; Karamustafalıoğlu, Oğuz

2015-01-01

Interactions between psychological, biological and environmental factors are important in development of trichotillomania and skin picking. The aim of this study is to determine the relationship of traumatic life events, symptoms of post-traumatic stress disorder and dissociation in patients with diagnoses of trichotillomania and skin picking disorder. The study included patients who was diagnosed with trichotillomania (n=23) or skin picking disorder (n=44), and healthy controls (n=37). Beck Depression Inventory, Traumatic Stress Symptoms Scale and Dissociative Experiences Scale were administered. All groups checked a list of traumatic life events to determine the exposed traumatic events. There was no statistical significance between three groups in terms of Dissociative Experiences Scale scores (P=0.07). But Beck Depression Inventory and Traumatic Stress Symptoms Scale scores of trichotillomania and skin picking groups were significantly higher than the control group. Subjects with a diagnosis of trichotillomania and skin picking reported statistically significantly higher numbers of traumatic and negative events in childhood compared to healthy subjects. We can conclude that trauma may play a role in development of both trichotillomania and skin picking. Increased duration of trichotillomania or skin picking was correlated with decreased presence of post-traumatic stress symptoms. The reason for the negatively correlation of severity of post-traumatic stress symptoms and self-harming behavior may be speculated as developing trichotillomania or skin picking symptoms helps the patient to cope with intrusive thoughts related to trauma. Future longitudinal research must focus on whether trauma and post-traumatic stress or trichotillomania and skin picking precede the development of mental disorder.

[Childbirth pain, perinatal dissociation and perinatal distress as predictors of posttraumatic stress symptoms].

PubMed

Boudou, M; Séjourné, N; Chabrol, H

2007-11-01

This prospective, longitudinal study investigated the contributive role of childbirth pain, perinatal distress and perinatal dissociation to the development of PTSD symptoms following childbirth. One hundred and seventeen women participated at the study. The first day after delivery they completed a questionnaire to evaluate pain, the peritraumatic distress inventory (PDI) and the peritraumatic dissociative experience questionnaire (PDEQ). Six weeks after birth, they completed the impact of event scale-revised (IES-R) to measure posttraumatic stress symptoms and the Edinburgh Postnatal Depression Scale (EPDS) to assess maternal depression. A multiple regression analysis revealed that only both components of perinatal distress, life-threat perception and dysphoric emotions were significant predictors of posttraumatic stress symptoms. In another multiple regression analysis predicting dysphoric emotions, affective dimension of pain was the only significant predictor. Perinatal distress was the best predictor of posttraumatic stress symptoms. Dysphoric emotions were associated with affective dimension of pain, suggesting that women distressed by the childbirth pain would have higher risk to develop posttraumatic stress symptoms.

Role of dissociation in "false drug allergy".

PubMed

Rodriguez-Cano, Teresa; Beato-Fernandez, Luis; Galindo-Bonilla, Pedro

2006-01-01

The aim of the present study was to analyze the influence of dissociation on the "false allergy" phenomenon. Fifty-five individuals (11 males and 44 females) who consecutively presented for the study of their suspected drug allergy were assessed. After the challenge test, false allergy was found in 39.3% and placebo positive response in 12.5% of the patients. Seven patients (12.5%) scored above the cut-off point of 20 on the Dissociative Experiences Scale (DES), and 5 out of this group (71.4%) fit in the "false allergy" group. Pathological scores on the DES were associated with the diagnosis of "false allergy" (OR = 9.583, 95% CI = 1.002, 91.621). The effect of age, gender, and other psychopathological variables was controlled. High levels of dissociation might predispose to false drug allergy, which could complicate pharmacological treatment and therefore increase the patient's complaints and demands for medical attention.

Dissociation predicts treatment response in eye-movement desensitization and reprocessing for posttraumatic stress disorder.

PubMed

Bae, Hwallip; Kim, Daeho; Park, Yong Chon

2016-01-01

Using clinical data from a specialized trauma clinic, this study investigated pretreatment clinical factors predicting response to eye-movement desensitization and reprocessing (EMDR) among adult patients diagnosed with posttraumatic stress disorder (PTSD). Participants were evaluated using the Clinician-Administered PTSD Scale (CAPS), the Symptom Checklist-90-Revised, the Beck Depression Inventory, and the Dissociative Experiences Scale before treatment and were reassessed using the CAPS after treatment and at 6-month follow-up. A total of 69 patients underwent an average of 4 sessions of EMDR, and 60 (87%) completed the posttreatment evaluation, including 8 participants who terminated treatment prematurely. Intent-to-treat analysis revealed that 39 (65%) of the 60 patients were classified as responders and 21 (35%) as nonresponders when response was defined as more than a 30% decrease in total CAPS score. The nonresponders had higher levels of dissociation (depersonalization and derealization) and numbing symptoms, but other PTSD symptoms, such as avoidance, hyperarousal, and intrusion, were not significantly different. The number of psychiatric comorbidities was also associated with treatment nonresponse. The final logistic regression model yielded 2 significant variables: dissociation (p < .001) and more than 2 comorbidities compared to none (p < .05). These results indicate that complex symptom patterns in PTSD may predict treatment response and support the inclusion of the dissociative subtype of PTSD in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.

Lipid levels in dissociative disorders: effects of psychodynamic psychotherapy.

PubMed

Damsa, Cristian; Lazignac, Coralie; Miller, Nick; Maris, Susanne; Adam, Eric; Rossignon, Kevin

2014-09-01

Although there are several data suggesting a link between lower lipids levels and the risk of suicide, there are few data concerning lower lipids levels in patients with dissociative disorders (DD). This is the first longitudinal study investigating the evolution of the lipids levels during a specific 8 weeks of psychodynamic psychotherapy (PP) for patients with DD. 32 patients diagnosed with DD (SCID for DSMIVR) were assessed with Dissociative Experiences Scale (DES), Clinical Global Impression and Improvement Scale and their lipids levels (total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein and very low density lipoprotein) were measured at inclusion and after 3 and 8 weeks of PP. 30 patients finished the study. There is a significant positive (p < 0.05) link between lower lipids levels (total cholesterol, LDL, triglycerids) and a higher level of dissociation (DES scores) at the beginning and at the end of the study. Interestingly, we found a significant (p = 0.018) positive link between the reduction of the dissociation (DES) and the increase of the triglycerides levels after 8 weeks of treatment. While lower lipids seems related to a higher level of dissociation before and after the treatment, an increasing triglycerides level was observed after 8 weeks of PP in patients with a better outcome. Further studies are needed with larger samples and control groups, in order to confirm these preliminary data. These findings could open the way for hypothesis about the role of lipids in the pathophysiology of DD and raise the question of the patients with DD receiving antilipidemiants agents.

Dissociative identity disorder among adolescents: prevalence in a university psychiatric outpatient unit.

PubMed

Sar, Vedat; Onder, Canan; Kilincaslan, Ayse; Zoroglu, Süleyman S; Alyanak, Behiye

2014-01-01

The aim of this study was to determine the prevalence of dissociative identity disorder (DID) and other dissociative disorders among adolescent psychiatric outpatients. A total of 116 consecutive outpatients between 11 and 17 years of age who were admitted to the child and adolescent psychiatry clinic of a university hospital for the 1st time were evaluated using the Adolescent Dissociative Experiences Scale, adolescent version of the Child Symptom Inventory-4, Childhood Trauma Questionnaire, and McMaster Family Assessment Device. All patients were invited for an interview with the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D) administered by 2 senior psychiatrists in a blind fashion. There was excellent interrater reliability between the 2 clinicians on SCID-D diagnoses and scores. Among 73 participants, 33 (45.2%) had a dissociative disorder: 12 (16.4%) had DID, and 21 (28.8%) had dissociative disorder not otherwise specified. There was no difference in gender distribution, childhood trauma, or family dysfunction scores between the dissociative and nondissociative groups. Childhood emotional abuse and family dysfunction correlated with self-reported dissociation. Of the dissociative adolescents, 93.9% had an additional psychiatric disorder. Among them, only separation anxiety disorder was significantly more prevalent than in controls. Although originally designed for adults, the SCID-D is promising for diagnosing dissociative disorders in adolescents, its modest congruence with self-rated dissociation and lack of relationship between diagnosis and childhood trauma and family dysfunction suggest that the prevalence rates obtained with this instrument originally designed for adults must be replicated. The introduction of diagnostic criteria for adolescent DID in revised versions of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, would refine the assessment of dissociative disorders in this age group.

[Dispute over the multiple personality disorder: theoretical or practical dilemma?].

PubMed

Stankiewicz, Sylwia; Golczyńska, Maria

2006-01-01

Dissociative identity disorder (DID) could also be referred to as multiple personality disorder (MPD). Due to rare occurrence and difficulty in its' identification it is infrequently diagnosed in Poland. The indicated disorder has been portrayed by the authors throughout the historical context, referring to initial 18th century's references concerning dissociation. A typical dissociatively disordered person has been characterized along with his individual personality categories such as: original personality, altered personality, host and personality fragment. Moreover various diagnosis criterions of DID have been introduced. DID has also been differentiated with other disorders: PTSD (post-traumatic stress disorder) and BPD (borderline personality disorder). A hypothesis has been set up, stating that DID is directly correlated with the trauma experienced during childhood, while PTSD is linked with traumatic lived-through events in the later period of ones' life. The most contemporary and frequently used research tools for DID have been indicated: dissociative experience scale (DES) and somatoform dissociation questionnaire (SDQ-20). Based upon the known literature, the authors have presented treatment methods such as hypnotherapy and recorded therapy sessions. It is the view of the authors that the switching in dissociative identity disorder is of adaptive character (it occurrs depending upon adaptive needs).

Relationships of dissociative disorders and personality traits in opium addicts on methadone treatment.

PubMed

Ghafarinezhad, Alireza; Rajabizadeh, Ghodratollah; Shahriari, Vahid

2013-01-01

Drug abuse is a major public health problem. Some believe that when dissociation fails to defend against emotional, physical, or sexual trauma, the person will find relief from unpleasant thoughts and emotions in opium use. On the other hand, personality disorders are considered as important predictors of treatment outcomes in drug abusers. Due to lack of adequate research in this regard, we evaluated dissociative disorders and personality traits of opium addicts on methadone treatment. This cross-sectional analytic study included 111 non-psychotic subjects on methadone treatment (case group) and 69 non-addicts (control group). After recording demographic characteristics, Dissociative Experiences Scale (DES) and Millon Multiaxial Inventory III were applied to assess dissociative symptoms and clinical personality patterns of all participants. Dissociative symptoms were significantly more common in the case group than in the control group (P = 0.044). While hysterionic personality disorder was more frequent in the control group (P = 0.008), sadistic, antisocial, and schizotypal personality disorders were significantly more common in the case group (P = 0.008, 0.002, and 0.023, respectively). We found relations between history of drug dependence, dissociative symptoms, and personality disorders. Therefore, the mentioned disorders need to be kept in mind while planning addiction treatment modalities and identifying high risk groups.

Trauma-Related Dissociation Is Linked With Maladaptive Personality Functioning

PubMed Central

Granieri, Antonella; Guglielmucci, Fanny; Costanzo, Antonino; Caretti, Vincenzo; Schimmenti, Adriano

2018-01-01

Background: Extensive research has demonstrated the positive associations among the exposure to traumatic experiences, the levels of dissociation, and the severity of psychiatric symptoms in adults. However, it has been hypothesized in clinical literature that an excessive activation of the dissociative processes following multiple traumatic experiences may jeopardize the psychological and behavioral functioning of the individuals, fostering higher levels of maladaptive personality functioning. Methods: The study involved 322 adult volunteers from Italy. Participants completed measures on traumatic experiences, dissociation, and maladaptive personality traits. Results: The number of traumatic experiences reported by participants were positively associated with dissociation scores and maladaptive personality scores. Mediation analyses showed that dissociation acted as a partial mediator in the relationship between traumatic experiences and overall maladaptive personality functioning. Regression curve analyses showed that the positive association between maladaptive personality functioning and dissociation was stronger among participants with higher exposure to traumatic experiences. Conclusion: Exposure to multiple traumatic experiences may increase the risk for an excessive activation of the dissociative processes, which in turn may generate severe impairments in multiple domains of personality functioning. PMID:29887807

Three cases of dissociative identity disorder and co-occurring borderline personality disorder treated with dynamic deconstructive psychotherapy.

PubMed

Chlebowski, Susan M; Gregory, Robert J

2012-01-01

Dissociative Identity Disorder (DID) is an under-researched entity and there are no clinical trials employing manual-based therapies and validated outcome measures. There is evidence that borderline personality disorder (BPD) commonly co-occurs with DID and can worsen its course. The authors report three cases of DID with co-occurring BPD that we successfully treated with a manual-based treatment, Dynamic Deconstructive Psychotherapy (DDP). Each of the three clients achieved a 34% to 79% reduction in their Dissociative Experiences Scale scores within 12 months of initiating therapy. Dynamic Deconstructive Psychotherapy was developed for treatment refractory BPD and differs in some respects from expert consensus treatment of DID. It may be a promising modality for DID complicated by co-occurring BPD.

Relationship of intentional self-harm using sharp objects with depressive and dissociative tendencies in pre-adolescence-adolescence.

PubMed

Sho, Noriko; Oiji, Arata; Konno, Chizue; Toyohara, Koji; Minami, Tatsuya; Arai, Takashi; Seike, Yoji

2009-06-01

The objectives of the present study were to (i) evaluate the prevalence of children and adolescents who have engaged in intentional self-harm using a sharp object; and (ii) investigate the relationship between self-harm with sharp objects and depressive tendencies or dissociative tendencies. A total of 1938 students in grades 5-12 in Yokohama, Japan, were enrolled, and they completed anonymous self-report questionnaires including a question about intentional self-harm with a sharp object, the Depression Self-Rating Scale for Children (DSRSC) and the Adolescent Dissociative Experiences Scale (A-DES). The prevalence of self-harm using sharp object was 5.4% among male 5th-6th graders, 4.0% among female 5th-6th graders, 5.3% among male 7th-9th graders, 15.1% among female 7th-9th graders, 6.6% among male 10th-12th graders, and 9.6% among female 10th-12th graders. Categorical regression analysis showed that a small amount of variance in self-harm by sharp object was explained by DSRSC and A-DES scores. Self-harm with a sharp object was prevalent among pre-adolescents and adolescents and was associated with depressive and dissociative tendencies.

Dissociation From a Cross-Cultural Perspective: Implications of Studies in Brazil.

PubMed

Maraldi, Everton de Oliveira; Krippner, Stanley; Barros, Maria Cristina Monteiro; Cunha, Alexandre

2017-07-01

A major issue in the study of dissociation concerns the cross-cultural validity of definitions and measurements used to identify and classify dissociative disorders. There is also extensive debate on the etiological factors underlying dissociative experiences. Cross-cultural research is essential to elucidate these issues, particularly regarding evidence obtained from countries in which the study of dissociation is still in its infancy. The aim of this article was to discuss Brazilian research on the topic of dissociation, highlighting its contributions for the understanding of dissociative experiences in nonclinical populations and for the validity and relevance of dissociative disorders in the contexts of psychiatry, psychology, and psychotherapy. We also consider the ways in which dissociative experiences are assimilated by Brazilian culture and religious expressions, and the implications of Brazilian studies for the sociocultural investigation of dissociation. We conclude by addressing the limitations of these studies and potential areas for future research.

Coupled numerical modeling of gas hydrates bearing sediments from laboratory to field-scale conditions

NASA Astrophysics Data System (ADS)

Sanchez, M. J.; Santamarina, C.; Gai, X., Sr.; Teymouri, M., Sr.

2017-12-01

Stability and behavior of Hydrate Bearing Sediments (HBS) are characterized by the metastable character of the gas hydrate structure which strongly depends on thermo-hydro-chemo-mechanical (THCM) actions. Hydrate formation, dissociation and methane production from hydrate bearing sediments are coupled THCM processes that involve, amongst other, exothermic formation and endothermic dissociation of hydrate and ice phases, mixed fluid flow and large changes in fluid pressure. The analysis of available data from past field and laboratory experiments, and the optimization of future field production studies require a formal and robust numerical framework able to capture the very complex behavior of this type of soil. A comprehensive fully coupled THCM formulation has been developed and implemented into a finite element code to tackle problems involving gas hydrates sediments. Special attention is paid to the geomechanical behavior of HBS, and particularly to their response upon hydrate dissociation under loading. The numerical framework has been validated against recent experiments conducted under controlled conditions in the laboratory that challenge the proposed approach and highlight the complex interaction among THCM processes in HBS. The performance of the models in these case studies is highly satisfactory. Finally, the numerical code is applied to analyze the behavior of gas hydrate soils under field-scale conditions exploring different features of material behavior under possible reservoir conditions.

Differential effects of childhood abuse and neglect: mediation by posttraumatic distress in neurotic disorder and negative symptoms in schizophrenia?

PubMed

Vogel, Matthias; Meier, Johanna; Grönke, Stephanie; Waage, Marco; Schneider, Wolfgang; Freyberger, Harald Jürgen; Klauer, Thomas

2011-08-30

Dissociation, though understood as a response to trauma, lacks a proven etiology. The assumption of a dose-response relationship between trauma, dissociation and Schneiderian symptoms led to the proposal of a dissociative subtype of schizophrenia characterized by severe child maltreatment, dissociation and psychosis. Child maltreatment and dissociation are common features of neurotic disorders as well, and the link between trauma, dissociation, and hallucinations is not specific for schizophrenia. This study compares childhood abuse and neglect, posttraumatic distress and adult dissociation in patients with psychotic vs. non-psychotic disorder. Thirty-five participants with non-psychotic disorder and twenty-five with schizophrenia were analyzed using the Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), the Montgomery-Åsberg Depression Rating Scale (MADRS), the Posttraumatic Stress Diagnostic Scale PDS (PDS), the Childhood Trauma Questionnaire (CTO) and the Arbeitsgemeinschaft Methodik und Dokumentation in der Psychiatrie (AMDP)-module on dissociation. Trauma and clinical syndromes were compared by means of T-testing and logistic regression between 1) the diagnoses and 2) groups with and without post-traumatic stress disorder (PTSD), marked dissociation and psychotic symptoms. While non-psychotic disorder was related to abuse, schizophrenia showed an association with neglect. Childhood trauma predicted posttraumatic symptomatology and negative symptoms. Childhood abuse and neglect may effectuate different outcomes in neurotic and psychotic disorder. The underlying mechanisms, including dissociation, dovetail with cognitive, emotional and behavioural changes involved in depression, posttraumatic distress and chronic schizophrenia symptoms rather than being directly linked to trauma. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ground and excited state dissociation dynamics of ionized 1,1-difluoroethene.

PubMed

Gridelet, E; Dehareng, D; Locht, R; Lorquet, A J; Lorquet, J C; Leyh, B

2005-09-22

The kinetic energy release distributions (KERDs) for the fluorine atom loss from the 1,1-difluoroethene cation have been recorded with two spectrometers in two different energy ranges. A first experiment uses dissociative photoionization with the He(I) and Ne(I) resonance lines, providing the ions with a broad internal energy range, up to 7 eV above the dissociation threshold. The second experiment samples the metastable range, and the average ion internal energy is limited to about 0.2 eV above the threshold. In both energy domains, KERDs are found to be bimodal. Each component has been analyzed by the maximum entropy method. The narrow, low kinetic energy components display for both experiments the characteristics of a statistical, simple bond cleavage reaction: constraint equal to the square root of the fragment kinetic energy and ergodicity index higher than 90%. Furthermore, this component is satisfactorily accounted for in the metastable time scale by the orbiting transition state theory. Potential energy surfaces corresponding to the five lowest electronic states of the dissociating 1,1-C2H2F2+ ion have been investigated by ab initio calculations at various levels. The equilibrium geometry of these states, their dissociation energies, and their vibrational wavenumbers have been calculated, and a few conical intersections between these surfaces have been identified. It comes out that the ionic ground state X2B1 is adiabatically correlated with the lowest dissociation asymptote. Its potential energy curve increases in a monotonic way along the reaction coordinate, giving rise to the narrow KERD component. Two states embedded in the third photoelectron band (B2A1 at 15.95 eV and C2B2 at 16.17 eV) also correlate with the lowest asymptote at 14.24 eV. We suggest that their repulsive behavior along the reaction coordinate be responsible for the KERD high kinetic energy contribution.

Differences in trauma history and psychopathology between PTSD patients with and without co-occurring dissociative disorders

PubMed Central

Wabnitz, Pascal; Gast, Ursula; Catani, Claudia

2013-01-01

Background The interplay between different types of potentially traumatizing events, posttraumatic symptoms, and the pathogenesis of PTSD or major dissociative disorders (DD) has been extensively studied during the last decade. However, the phenomenology and nosological classification of posttraumatic disorders is currently under debate. The current study was conducted to investigate differences between PTSD patients with and without co-occurring major DD with regard to general psychopathology, trauma history, and trauma-specific symptoms. Methods Twenty-four inpatients were administered the Clinician-Administered PTSD Scale for DSM-IV (CAPS) and the Mini-Structured Clinical Interview for DSM-IV Dissociative Disorders (MINI-SKID-D) to assess DD and PTSD. Additionally, participants completed questionnaires to assess general psychopathology and health status. Results Symptom profiles and axis I comorbidity were similar in all patients. Traumatic experiences did not differ between the two groups, with both reporting high levels of childhood trauma. Only trauma-specific avoidance behavior and dissociative symptoms differed between groups. Conclusion Results support the view that PTSD and DD are affiliated disorders that could be classified within the same diagnostic category. Our results accord with a typological model of dissociation in which profound forms of dissociation are specific to DD and are accompanied with higher levels of trauma-specific avoidance in DD patients. PMID:24298325

Differences in trauma history and psychopathology between PTSD patients with and without co-occurring dissociative disorders.

PubMed

Wabnitz, Pascal; Gast, Ursula; Catani, Claudia

2013-01-01

The interplay between different types of potentially traumatizing events, posttraumatic symptoms, and the pathogenesis of PTSD or major dissociative disorders (DD) has been extensively studied during the last decade. However, the phenomenology and nosological classification of posttraumatic disorders is currently under debate. The current study was conducted to investigate differences between PTSD patients with and without co-occurring major DD with regard to general psychopathology, trauma history, and trauma-specific symptoms. Twenty-four inpatients were administered the Clinician-Administered PTSD Scale for DSM-IV (CAPS) and the Mini-Structured Clinical Interview for DSM-IV Dissociative Disorders (MINI-SKID-D) to assess DD and PTSD. Additionally, participants completed questionnaires to assess general psychopathology and health status. Symptom profiles and axis I comorbidity were similar in all patients. Traumatic experiences did not differ between the two groups, with both reporting high levels of childhood trauma. Only trauma-specific avoidance behavior and dissociative symptoms differed between groups. Results support the view that PTSD and DD are affiliated disorders that could be classified within the same diagnostic category. Our results accord with a typological model of dissociation in which profound forms of dissociation are specific to DD and are accompanied with higher levels of trauma-specific avoidance in DD patients.

Molecular model for the diffusion of associating telechelic polymer networks

NASA Astrophysics Data System (ADS)

Ramirez, Jorge; Dursch, Thomas; Olsen, Bradley

Understanding the mechanisms of motion and stress relaxation of associating polymers at the molecular level is critical for advanced technological applications such as enhanced oil-recovery, self-healing materials or drug delivery. In associating polymers, the strength and rates of association/dissociation of the reversible physical crosslinks govern the dynamics of the network and therefore all the macroscopic properties, like self-diffusion and rheology. Recently, by means of forced Rayleigh scattering experiments, we have proved that associating polymers of different architectures show super-diffusive behavior when the free motion of single molecular species is slowed down by association/dissociation kinetics. Here we discuss a new molecular picture for unentangled associating telechelic polymers that considers concentration, molecular weight, number of arms of the molecules and equilibrium and rate constants of association/dissociation. The model predicts super-diffusive behavior under the right combination of values of the parameters. We discuss some of the predictions of the model using scaling arguments, show detailed results from Brownian dynamics simulations of the FRS experiments, and attempt to compare the predictions of the model to experimental data.

MDMA-Induced Dissociative State not Mediated by the 5-HT2A Receptor

PubMed Central

Puxty, Drew J.; Ramaekers, Johannes G.; de la Torre, Rafael; Farré, Magí; Pizarro, Neus; Pujadas, Mitona; Kuypers, Kim P. C.

2017-01-01

Previous research has shown that a single dose of MDMA induce a dissociative state, by elevating feelings of depersonalization and derealization. Typically, it is assumed that action on the 5-HT2A receptor is the mechanism underlying these psychedelic experiences. In addition, other studies have shown associations between dissociative states and biological parameters (heart rate, cortisol), which are elevated by MDMA. In order to investigate the role of the 5-HT2 receptor in the MDMA-induced dissociative state and the association with biological parameters, a placebo-controlled within-subject study was conducted including a single oral dose of MDMA (75 mg), combined with placebo or a single oral dose of the 5-HT2 receptor blocker ketanserin (40 mg). Twenty healthy recreational MDMA users filled out a dissociative states scale (CADSS) 90 min after treatments, which was preceded and followed by assessment of a number of biological parameters (cortisol levels, heart rate, MDMA blood concentrations). Findings showed that MDMA induced a dissociative state but this effect was not counteracted by pre-treatment with ketanserin. Heart rate was the only biological parameter that correlated with the MDMA-induced dissociative state, but an absence of correlation between these measures when participants were pretreated with ketanserin suggests an absence of directional effects of heart rate on dissociative state. It is suggested that the 5-HT2 receptor does not mediate the dissociative effects caused by a single dose of MDMA. Further research is needed to determine the exact neurobiology underlying this effect and whether these effects contribute to the therapeutic potential of MDMA. PMID:28744219

MDMA-Induced Dissociative State not Mediated by the 5-HT2A Receptor.

PubMed

Puxty, Drew J; Ramaekers, Johannes G; de la Torre, Rafael; Farré, Magí; Pizarro, Neus; Pujadas, Mitona; Kuypers, Kim P C

2017-01-01

Previous research has shown that a single dose of MDMA induce a dissociative state, by elevating feelings of depersonalization and derealization. Typically, it is assumed that action on the 5-HT 2A receptor is the mechanism underlying these psychedelic experiences. In addition, other studies have shown associations between dissociative states and biological parameters (heart rate, cortisol), which are elevated by MDMA. In order to investigate the role of the 5-HT 2 receptor in the MDMA-induced dissociative state and the association with biological parameters, a placebo-controlled within-subject study was conducted including a single oral dose of MDMA (75 mg), combined with placebo or a single oral dose of the 5-HT 2 receptor blocker ketanserin (40 mg). Twenty healthy recreational MDMA users filled out a dissociative states scale (CADSS) 90 min after treatments, which was preceded and followed by assessment of a number of biological parameters (cortisol levels, heart rate, MDMA blood concentrations). Findings showed that MDMA induced a dissociative state but this effect was not counteracted by pre-treatment with ketanserin. Heart rate was the only biological parameter that correlated with the MDMA-induced dissociative state, but an absence of correlation between these measures when participants were pretreated with ketanserin suggests an absence of directional effects of heart rate on dissociative state. It is suggested that the 5-HT 2 receptor does not mediate the dissociative effects caused by a single dose of MDMA. Further research is needed to determine the exact neurobiology underlying this effect and whether these effects contribute to the therapeutic potential of MDMA.

Coping strategies, hope, and treatment efficacy in pharmacoresistant inpatients with neurotic spectrum disorders

PubMed Central

Ociskova, Marie; Prasko, Jan; Kamaradova, Dana; Grambal, Ales; Kasalova, Petra; Sigmundova, Zuzana; Latalova, Klara; Vrbova, Kristyna

2015-01-01

Background Approximately 30%–60% of patients with neurotic spectrum disorders remain symptomatic despite treatment. Identifying the predictors of good response to psychiatric and psychotherapeutic treatment may be useful for increasing treatment efficacy in neurotic patients. The objective of this study was to investigate the influence of hope, coping strategies, and dissociation on the treatment response of this group of patients. Methods Pharmacoresistant patients, who underwent a 6-week psychotherapeutic program, were enrolled in the study. All patients completed the Clinical Global Impression (CGI) – both objective and subjective forms, Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI)-II at baseline and after 6 weeks. The COPE Inventory, the Adult Dispositional Hope Scale (ADHS), and the Dissociative Experiences Scale (DES) were completed at the start of the treatment. Results Seventy-six patients completed the study. The mean scores for all scales measuring the severity of the disorders (BAI, BDI-II, subjective and objective CGI) significantly decreased during the treatment. Several subscores of the COPE Inventory, the overall score of ADHS, and the overall score of DES significantly correlated with the treatment outcome. Multiple regression was used to find out which factors were the most significant predictors of the therapeutic outcomes. The most important predictors of the treatment response were the overall levels of hope and dissociation. Conclusion According to our results, a group of patients with a primary neurotic disorder, who prefer the use of maladaptive coping strategies, feel hopelessness, and have tendencies to dissociate, showed poor response to treatment. PMID:26028972

The Parenting Experiences of Mothers with Dissociative Disorders.

ERIC Educational Resources Information Center

Benjamin, Lynn R.; Benjamin, Robert; Rind, Bruce

1998-01-01

Presents a qualitative analysis of the experience of parenting of mothers with dissociative disorders. Using the mothers' words, describes how the five symptom areas of dissociation impeded their parenting efforts. Discusses the necessity of addressing parenting in the treatment of client-mothers with dissociative disorders. (Author/MKA)

Childhood trauma and dissociation among women with genito-pelvic pain/penetration disorder

PubMed Central

Özen, Beliz; Özdemir, Y Özay; Beştepe, E Emrem

2018-01-01

Objective Causes such as childhood trauma, negative attitude about sexuality, inadequate sexual knowledge and education, relationship problems, and unconscious motivation are reported about psychosexual development in the etiology of genito-pelvic pain/penetration disorder (GPP/PD). There are few studies that focus directly on research etiology of GPP/PD and use structured scales. The aim of this study was to research childhood trauma and dissociation forms among women with GPP/PD. Patients and methods Fifty-five women with GPP/PD according to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders and 61 healthy women with no complaints of sexual function as a control group, in the age range of 18–60 years, were included in this study. Sociodemographic data form, Childhood Trauma Questionnaire (CTQ-28), Dissociative Experiences Scale (DES), and Somatoform Dissociation Questionnaire (SDQ-20) were administered to all participants. Results Sexual abuse, emotional abuse, and emotional neglect scores, which comprise the subgroups of CTQ, were found high among women with GPP/PD compared with the control group (p=0.003, p=0.006, p=0.001). While a significant difference between the two groups’ SDQ scores was obtained (p=0.000), no significant difference was detected between the two groups’ DES scores (p=0.392). Discussion The results evoke the question are genitopelvic pain conditions, vaginismus and dyspareunia, that cannot be explained with a medical cause and that cause penetration disorder, a kind of dissociative symptom prone to develop in some women with childhood psychogenic trauma. PMID:29503548

Impact of dissociation on treatment of depressive and anxiety spectrum disorders with and without personality disorders

PubMed Central

Prasko, Jan; Grambal, Ales; Kasalova, Petra; Kamardova, Dana; Ociskova, Marie; Holubova, Michaela; Vrbova, Kristyna; Sigmundova, Zuzana; Latalova, Klara; Slepecky, Milos; Zatkova, Marta

2016-01-01

Objective The central goal of the study was to analyze the impact of dissociation on the treatment effectiveness in patients with anxiety/neurotic spectrum and depressive disorders with or without comorbid personality disorders. Methods The research sample consisted of inpatients who were hospitalized in the psychiatric department and met the ICD-10 criteria for diagnosis of depressive disorder, panic disorder, generalized anxiety disorder, mixed anxiety–depressive disorder, agoraphobia, social phobia, obsessive compulsive disorder, posttraumatic stress disorder, adjustment disorders, dissociative/conversion disorders, somatoform disorder, or other anxiety/neurotic spectrum disorder. The participants completed these measures at the start and end of the therapeutic program – Beck Depression Inventory, Beck Anxiety Inventory, a subjective version of Clinical Global Impression-Severity, Sheehan Patient-Related Anxiety Scale, and Dissociative Experience Scale. Results A total of 840 patients with anxiety or depressive spectrum disorders, who were resistant to pharmacological treatment on an outpatient basis and were referred for hospitalization for the 6-week complex therapeutic program, were enrolled in this study. Of them, 606 were statistically analyzed. Data from the remaining 234 (27.86%) patients were not used because of various reasons (103 prematurely finished the program, 131 did not fill in most of the questionnaires). The patients’ mean ratings on all measurements were significantly reduced during the treatment. Also, 67.5% reached at least minimal improvement (42.4% showed moderate and more improvement, 35.3% of the patients reached remission). The patients without comorbid personality disorder improved more significantly in the reduction of depressive symptoms than those with comorbid personality disorder. However, there were no significant differences in change in anxiety levels and severity of the mental issues between the patients with and without personality disorders. Higher degree of dissociation at the beginning of the treatment predicted minor improvement, and also, higher therapeutic change was connected to greater reduction of the dissociation level. Conclusion Dissociation is an important factor that influences the treatment effectiveness in anxiety/depression patients with or without personality disorders resistant to previous treatment. Targeting dissociation in the treatment of these disorders may be beneficial. PMID:27799774

Impact of dissociation on treatment of depressive and anxiety spectrum disorders with and without personality disorders.

PubMed

Prasko, Jan; Grambal, Ales; Kasalova, Petra; Kamardova, Dana; Ociskova, Marie; Holubova, Michaela; Vrbova, Kristyna; Sigmundova, Zuzana; Latalova, Klara; Slepecky, Milos; Zatkova, Marta

2016-01-01

The central goal of the study was to analyze the impact of dissociation on the treatment effectiveness in patients with anxiety/neurotic spectrum and depressive disorders with or without comorbid personality disorders. The research sample consisted of inpatients who were hospitalized in the psychiatric department and met the ICD-10 criteria for diagnosis of depressive disorder, panic disorder, generalized anxiety disorder, mixed anxiety-depressive disorder, agoraphobia, social phobia, obsessive compulsive disorder, posttraumatic stress disorder, adjustment disorders, dissociative/conversion disorders, somatoform disorder, or other anxiety/neurotic spectrum disorder. The participants completed these measures at the start and end of the therapeutic program - Beck Depression Inventory, Beck Anxiety Inventory, a subjective version of Clinical Global Impression-Severity, Sheehan Patient-Related Anxiety Scale, and Dissociative Experience Scale. A total of 840 patients with anxiety or depressive spectrum disorders, who were resistant to pharmacological treatment on an outpatient basis and were referred for hospitalization for the 6-week complex therapeutic program, were enrolled in this study. Of them, 606 were statistically analyzed. Data from the remaining 234 (27.86%) patients were not used because of various reasons (103 prematurely finished the program, 131 did not fill in most of the questionnaires). The patients' mean ratings on all measurements were significantly reduced during the treatment. Also, 67.5% reached at least minimal improvement (42.4% showed moderate and more improvement, 35.3% of the patients reached remission). The patients without comorbid personality disorder improved more significantly in the reduction of depressive symptoms than those with comorbid personality disorder. However, there were no significant differences in change in anxiety levels and severity of the mental issues between the patients with and without personality disorders. Higher degree of dissociation at the beginning of the treatment predicted minor improvement, and also, higher therapeutic change was connected to greater reduction of the dissociation level. Dissociation is an important factor that influences the treatment effectiveness in anxiety/depression patients with or without personality disorders resistant to previous treatment. Targeting dissociation in the treatment of these disorders may be beneficial.

Daily stress interacts with trait dissociation to predict sleep-related experiences in young adults.

PubMed

Soffer-Dudek, Nirit; Shahar, Golan

2011-08-01

Building on the previously documented effects of stress and dissociation on sleep and dreaming, we examined their interactive role in general sleep-related experiences (GSEs; e.g., nightmares, falling dreams, hypnagogic hallucinations; see Watson, 2001). Stress, sleep quality, and GSEs were assessed daily for 14 days among young adults. Baseline assessment included life stress, sleep quality, psychopathology, dissociation, and related dimensions. Multilevel analyses indicated that daily stress brings about GSEs among highly dissociative young adults. Additionally, baseline trait dissociation predicted within-subject elevation in GSEs when daily stress was high. Flawed sleep-wake transitions, previously linked to dissociation and sleep-related experiences, might account for this effect. © 2011 American Psychological Association

Dissociation mediates the relationship between peer victimization and hallucinatory experiences among early adolescents.

PubMed

Yamasaki, Syudo; Ando, Shuntaro; Koike, Shinsuke; Usami, Satoshi; Endo, Kaori; French, Paul; Sasaki, Tsukasa; Furukawa, Toshi A; Hasegawa-Hiraiwa, Mariko; Kasai, Kiyoto; Nishida, Atsushi

2016-06-01

Peer victimization increases the risk of experiencing psychotic symptoms among clinical and general populations, but the mechanism underlying this association remains unclear. Dissociation, which is related to peer victimization and hallucinatory experiences, has been demonstrated as a significant mediator in the relation between childhood victimization and hallucinatory experience among adult patients with psychosis. However, no studies have examined the mediating effect of dissociation in a general early adolescent population. We examined whether dissociation mediates the relationship between peer victimization and hallucinatory experiences among 10-year-old adolescents using a population-based cross-sectional survey of early adolescents and their main parent (Tokyo Early Adolescence Survey; N  = 4478). We examined the mediating effect of dissociation, as well as external locus of control and depressive symptoms, on the relationship between peer victimization and hallucinatory experiences using path analysis. The model assuming mediation effects indicated good model fit (comparative fit index = .999; root mean square error of approximation = .015). The mediation effect between peer victimization and hallucination via dissociation (standardized indirect effect = .038, p  < .001) was statistically significant, whereas the mediation effects of depressive symptoms (standardized indirect effect = -.0066, p  = 0.318) and external locus of control (standardized indirect effect = .0024, p  = 0.321) were not significant. These results suggest that dissociation is a mediator in the relation between peer victimization and hallucinatory experiences in early adolescence. For appropriate intervention strategies, assessing dissociation and peer victimization as they affect hallucinatory experiences is necessary.

Emission line shapes produced by dissociative excitation of atmospheric gases

NASA Technical Reports Server (NTRS)

Zipf, E. C.; Wells, W. C.

1980-01-01

The spectral line shapes of the radiation emitted from O atoms produced by the dissociative excitation of O2, CO, CO2 and NO are investigated. Doppler line shapes are derived from time-of-flight spectra of O (5S0) atoms decaying by the emission of 1356-A radiation after being produced in electron impact experiments at incident electron energies from 25 to 300 eV. It is shown that the effective line width of the radiation is large compared with the Doppler absorption widths of ambient O atoms in both photoelectron and auroral excitation, and thus the dissociatively excited component of the O I 1304-A airglow will behave as though it were optically thin, exhibiting pronounced limb brightening effects and a scale height characteristic of the initial, local source function. It is found that the average kinetic energy of the dissociation fragments inferred from O I (5S) time-of-flight spectra is in good agreement with that of O I (3S) atoms in the electron impact dissociation of CO2, although not for O2. Finally, it is suggested that although electron impact dissociation of CO and CO2 contributes to the 1304-A emission in the upper atmosphere of Venus, it cannot be the dominant source of this radiation since the absolute cross sections for the reaction are too small.

Development, Reliability, and Validity of a Child Dissociation Scale.

ERIC Educational Resources Information Center

Putnam, Frank W.; And Others

1993-01-01

Evaluation of the Child Dissociative Checklist found it to be a reliable and valid observer report measure of dissociation in children, including sexually abused girls and children with dissociative disorder and with multiple personality disorder. The checklist, which is appended, is intended as a clinical screening instrument and research measure…

Comfortably Numb: The Role of Momentary Dissociation in the Experience of Negative Affect Around Binge Eating.

PubMed

Mason, Tyler B; Lavender, Jason M; Wonderlich, Stephen A; Steiger, Howard; Cao, Li; Engel, Scott G; Mitchell, James E; Crosby, Ross D

2017-05-01

Evidence suggests that both dissociation and negative affect (NA) may precipitate binge eating. The extent to which dissociation may impact the experience of NA around binge eating is unclear. Women with bulimia nervosa completed a 2-week ecological momentary assessment protocol of dissociation, NA, and binge eating. Multilevel modeling was used to examine dissociation as a moderator of NA before and after binge eating. NA was greater at the time of binge eating for participants higher in average dissociation (between subjects) and when momentary dissociation was greater than one's average (within subjects). The trajectory of NA was characterized by a sharper increase before binge eating for participants higher in average dissociation; the NA trajectories were characterized by sharper increases before and decreases after binge eating when momentary dissociation was greater than one's average. Results support the salience of both dissociation and NA in relation to the occurrence of binge eating.

Experimentally-induced dissociation impairs visual memory.

PubMed

Brewin, Chris R; Mersaditabari, Niloufar

2013-12-01

Dissociation is a phenomenon common in a number of psychological disorders and has been frequently suggested to impair memory for traumatic events. In this study we explored the effects of dissociation on visual memory. A dissociative state was induced experimentally using a mirror-gazing task and its short-term effects on memory performance were investigated. Sixty healthy individuals took part in the experiment. Induced dissociation impaired visual memory performance relative to a control condition; however, the degree of dissociation was not associated with lower memory scores in the experimental group. The results have theoretical and practical implications for individuals who experience frequent dissociative states such as patients with posttraumatic stress disorder (PTSD). Copyright © 2013 Elsevier Inc. All rights reserved.

Dissociative detachment and memory impairment: reversible amnesia or encoding failure?

PubMed

Allen, J G; Console, D A; Lewis, L

1999-01-01

The authors propose that clinicians endeavor to differentiate between reversible and irreversible memory failures in patients with dissociative symptoms who report "memory gaps" and "lost time." The classic dissociative disorders, such as dissociative amnesia and dissociative identity disorder, entail reversible memory failures associated with encoding experience in altered states. The authors propose another realm of memory failures associated with severe dissociative detachment that may preclude the level of encoding of ongoing experience needed to support durable autobiographical memories. They describe how dissociative detachment may be intertwined with neurobiological factors that impair memory, and they spell out the significance of distinguishing reversible and irreversible memory impairment for diagnosis, patient education, psychotherapy, and research.

Paranormal experiences in the general population.

PubMed

Ross, C A; Joshi, S

1992-06-01

The Dissociative Disorders Interview Schedule was administered to a random sample of 502 adults in the general population of Winnipeg, a midwestern Canadian city. Results showed that paranormal/extrasensory experiences were common in the general population. They were linked to a history of childhood trauma and to other dissociative symptom clusters. A factor analysis of the paranormal experiences identified three factors which together accounted for 44.0% of the combined variance of the scores. A model is proposed in which paranormal experiences are conceptualized as an aspect of normal dissociation. Like dissociation in general, paranormal experiences can be triggered by trauma, especially childhood physical or sexual abuse. Such experiences discriminate individuals with childhood trauma histories from those without at high levels of significance.

Volume change associated with formation and dissociation of hydrate in sediment

USGS Publications Warehouse

Ruppel, Carolyn D.; Lee, J.Y.; Santamarina, J. Carlos

2017-01-01

Gas hydrate formation and dissociation in sediments are accompanied by changes in the bulk volume of the sediment and can lead to changes in sediment properties, loss of integrity for boreholes, and possibly regional subsidence of the ground surface over areas where methane might be produced from gas hydrate in the future. Experiments on sand, silts, and clay subject to different effective stress and containing different saturations of hydrate formed from dissolved phase tetrahydrofuran are used to systematically investigate the impact of gas hydrate formation and dissociation on bulk sediment volume. Volume changes in low specific surface sediments (i.e., having a rigid sediment skeleton like sand) are much lower than those measured in high specific surface sediments (e.g., clay). Early hydrate formation is accompanied by contraction for all soils and most stress states in part because growing gas hydrate crystals buckle skeletal force chains. Dilation can occur at high hydrate saturations. Hydrate dissociation under drained, zero lateral strain conditions is always associated with some contraction, regardless of soil type, effective stress level, or hydrate saturation. Changes in void ratio during formation-dissociation decrease at high effective stress levels. The volumetric strain during dissociation under zero lateral strain scales with hydrate saturation and sediment compressibility. The volumetric strain during dissociation under high shear is a function of the initial volume average void ratio and the stress-dependent critical state void ratio of the sediment. Other contributions to volume reduction upon hydrate dissociation are related to segregated hydrate in lenses and nodules. For natural gas hydrates, some conditions (e.g., gas production driven by depressurization) might contribute to additional volume reduction by increasing the effective stress.

An outpatient clinical study of dissociative disorder not otherwise specified.

PubMed

Yanartaş, Ömer; Özmen, Hülya Akar; Citak, Serhat; Zincir, Selma Bozkurt; Sünbül, Esra Aydin

2014-05-01

The relatively high prevalence of the diagnosis of dissociative disorder not otherwise specified is frequently considered to be disproportionate. The disproportionate rate of this diagnosis is thought to be related to nosologic and/or diagnostic issues in dissociative identity disorder. We sought to investigate and compare the symptom patterns of these two clinical entities. We conducted a cross-sectional study involving 1314 participants who were screened with the Dissociative Experience Scale (DES) and the Somatoform Dissociation Questionnaire (SDQ). Of the participants, 272 who scored above the cut-off points for the screening questionnaires (DES score>30 and/or SDQ score>40 points) were invited to complete a structured interview using the Dissociative Disorders Interview Schedule (DDIS); of this subsample, only 190 participants agreed to participate in the second phase of the study. The mean score for the DES was 18.55±17.23, and the mean score for the SDQ was 30.19±13.32. Of the 190 participants, 167 patients were diagnosed as having a dissociative disorder (87.8%). We found that DD-NOS was the most prevalent category of dissociative disorder. There was a significantly larger percentage of patients in the DID group than in the DD-NOS group according to secondary features of DID and Schneiderian symptoms. The secondary features of DID and Schneiderian symptoms appeared to be more specific for DID, while no differences were detected between DID and DD-NOS based on most of the items on the SCL 90R. Further longitudinal studies are needed to determine the features that are similar and dissimilar between DD-NOS and DID. Copyright © 2014 Elsevier Inc. All rights reserved.

A latent class analysis of dissociation and posttraumatic stress disorder: evidence for a dissociative subtype.

PubMed

Wolf, Erika J; Miller, Mark W; Reardon, Annemarie F; Ryabchenko, Karen A; Castillo, Diane; Freund, Rachel

2012-07-01

The nature of the relationship of dissociation to posttraumatic stress disorder (PTSD) is controversial and of considerable clinical and nosologic importance. To examine evidence for a dissociative subtype of PTSD and to examine its association with different types of trauma. A latent profile analysis of cross-sectional data from structured clinical interviews indexing DSM-IV symptoms of current PTSD and dissociation. The VA Boston Healthcare System and the New Mexico VA Health Care System. A total of 492 veterans and their intimate partners, all of whom had a history of trauma. Participants reported exposure to a variety of traumatic events, including combat, childhood physical and sexual abuse, partner abuse, motor vehicle accidents, and natural disasters, with most participants reporting exposure to multiple types of traumatic events. Forty-two percent of the sample met the criteria for a current diagnosis of PTSD. Item-level scores on the Clinician-Administered PTSD Scale. A latent profile analysis suggested a 3-class solution: a low PTSD severity subgroup, a high PTSD severity subgroup characterized by elevations across the 17 core symptoms of the disorder, and a small but distinctly dissociative subgroup that composed 12% of individuals with a current diagnosis of PTSD. The latter group was characterized by severe PTSD symptoms combined with marked elevations on items assessing flashbacks, derealization, and depersonalization. Individuals in this subgroup also endorsed greater exposure to childhood and adult sexual trauma compared with the other 2 groups, suggesting a possible etiologic link with the experience of repeated sexual trauma. These results support the subtype hypothesis of the association between PTSD and dissociation and suggest that dissociation is a highly salient facet of posttraumatic psychopathology in a subset of individuals with the disorder.

Distinguishing simulated from genuine dissociative identity disorder on the MMPI-2.

PubMed

Brand, Bethany L; Chasson, Gregory S

2015-01-01

Due to high elevations on validity and clinical scales on personality and forensic measures, it is challenging to determine if individuals presenting with symptoms of dissociative identity disorder (DID) are genuine or not. Little research has focused on malingering DID, or on the broader issue of the profiles these patients obtain on the Minnesota Multiphasic Personality Inventory (MMPI-2), despite increasing awareness of dissociation. This study sought to characterize the MMPI-2 profiles of DID patients and to determine the utility of the MMPI-2 in distinguishing DID patients from uncoached and coached DID simulators. The analyses revealed that Infrequency, Back Infrequency, and Infrequency-Psychopathology (Fp) distinguished simulators from genuine DID patients. Fp was best able to discriminate simulated DID. Utility statistics and classification functions are provided for classifying individual profiles as indicative of genuine or simulated DID. Despite exposure to information about DID, the simulators were not able to accurately feign DID, which is inconsistent with the iatrogenic/sociocultural model of DID. Given that dissociation was strongly associated with elevations in validity, as well as clinical scales, including Scale 8 (i.e., Schizophrenia), considerable caution should be used in interpreting validity scales as indicative of feigning, and Scale 8 as indicative of schizophrenia, among highly dissociative individuals. (c) 2015 APA, all rights reserved).

Childhood trauma and dissociation in women with pseudoseizure-type conversion disorder.

PubMed

Ozcetin, Adnan; Belli, Hasan; Ertem, Umit; Bahcebasi, Talat; Ataoglu, Ahmet; Canan, Fatih

2009-11-01

Conversion disorder is thought to be associated with psychological factors because of the presence of conflict and other stressors prior to the condition. The aim of this study is to compare adult patients with pseudoseizure-type conversion disorder with healthy control group in terms of childhood trauma, dissociative disorder and family history of psychiatric disorders. 56 female patients were admitted to the general psychiatry hospital outpatient clinic between January and July 2005. All patients had a negative experience about their families just before having the conversion. Diagnosis was made according to the DSM-IV criteria. A control group consisting of similar patient demographics of the disease group has been selected. Socio-demographic information forms, the Childhood Trauma Questionnaire (CTQ) and Dissociation Questionnaire (DIS-Q), were completed on the patients. CTQ total (t=12.12, P<0.001) and subscales, emotional abuse and emotional neglect (EA-EN) (t=12.74, P<0.001), physical abuse (PA) (t=10.05, P<0.001), and sexual abuse (SA) (t=7.69, P<0.001) were significantly high in the conversion group. DIS-Q mean points were statistically higher in the conversion group (t=11.05, P<0.001). The findings suggest that pseudoseizures (conversion disorder) should be included within dissociative disorders in DSM system as in ICD. It is usually uncommon for the patient to tell about childhood trauma without being specially questioned about this issue. Thus, it would be helpful to uncover these experiences by using related scales in conversion disorder patients.

Psychedelic symptoms of cannabis and cocaine use as a function of trait impulsivity.

PubMed

van Wel, J H P; Spronk, D B; Kuypers, K P C; Theunissen, E L; Toennes, S W; Verkes, R J; Ramaekers, J G

2015-03-01

Trait impulsivity has been linked to addiction in humans. It has been suggested that drug users with high trait impulsivity levels are more sensitive to subjective drug intoxication. This study assessed whether subjective response to drugs differs between drug users with normal or high levels of trait impulsivity. Regular drug users (N = 122) received doses of cocaine HCl, cannabis, and placebo in a three-way crossover study. Their mood, dissociative state, and psychedelic symptoms were measured with subjective rating scales (CADDS, Bowdle, POMS). Trait impulsivity was assessed with the Barratt Impulsiveness Scale. Cannabis increased dissociation and psychedelic state, as well as fatigue, confusion, depression and anxiety, and decreased arousal, positive mood, vigor, friendliness, and elation. Cocaine increased dissociation, psychedelic state, vigor, friendliness, elation, positive mood, anxiety and arousal, while decreasing fatigue. Only a few subjective items revealed a drug × trait impulsivity interaction, suggesting that psychedelic symptoms were most intense in high impulsivity subjects. Trait impulsiveness ratings were negatively correlated with ratings of vigor (r = -.197) and positively correlated with ratings of loss of thought control (r = .237) during cannabis intoxication. It is concluded that a broad association between trait impulsivity and psychedelic subjective drug experience appears to be absent. © The Author(s) 2015.

Relationships between a Dissociative Subtype of PTSD and Clinical Characteristics in Patients with Substance Use Disorders.

PubMed

Mergler, Michaela; Driessen, Martin; Lüdecke, Christel; Ohlmeier, Martin; Chodzinski, Claudia; Weirich, Steffen; Schläfke, Detlef; Wedekind, Dirk; Havemann-Reinecke, Ursula; Renner, Walter; Schäfer, Ingo

2017-01-01

The increasing support for a dissociative subtype of post-traumatic stress disorder (PTSD-D) has led to its inclusion in DSM-5. We examined relationships between PTSD-D and relevant variables in patients with substance use disorders (SUD). The sample comprised N = 459 patients with SUD. The International Diagnostic Checklist and the Posttraumatic Diagnostic Scale were used to diagnose PTSD. In addition, participants completed the Childhood Trauma Questionnaire and the Dissociative Experiences Scale. The course of SUD was assessed by means of the European Addiction Severity Index. One-fourth of participants fulfilled a diagnosis of PTSD (25.3%). Patients with PTSD-D (N = 32, 27.6% of all patients with PTSD) reported significantly more current depressive symptoms, more current suicidal thoughts, more lifetime anxiety/tension, and more suicide attempts. The PTSD-D group also showed a significantly higher need for treatment due to drug problems, higher current use of opiates/analgesics, and a higher number of lifetime drug overdoses. In a regression model, symptoms of depression in the last month and lifetime suicide attempts significantly predicted PTSD-D. These findings suggest that PTSD-D is related to additional psychopathology and to a more severe course of substance-related problems in patients with SUD, indicating that this group also has additional treatment needs.

Is there a dissociative process in sleepwalking and night terrors?

PubMed Central

Hartman, D; Crisp, A; Sedgwick, P; Borrow, S

2001-01-01

The enduring and contentious hypothesis that sleepwalking and night terrors are symptomatic of a protective dissociative mechanism is examined. This is mobilised when intolerable impulses, feelings and memories escape, within sleep, the diminished control of mental defence mechanisms. They then erupt but in a limited motoric or affective form with restricted awareness and subsequent amnesia for the event. It has also been suggested that such processes are more likely when the patient has a history of major psychological trauma. In a group of 22 adult patients, referred to a tertiary sleep disorders service with possible sleepwalking/night terrors, diagnosis was confirmed both clinically and polysomnographically, and only six patients had a history of such trauma. More commonly these described sleepwalking/night terrors are associated with vivid dream-like experiences or behaviour related to flight from attack. Two such cases, suggestive of a dissociative process, are described in more detail.
The results of this study are presented largely on account of the negative findings. Scores on the dissociation questionnaire (DIS-Q) were normal, although generally higher in the small "trauma" subgroup. These were similar to scores characterising individuals with post-traumatic stress disorder. This "trauma" group also scored particularly highly on the anxiety, phobic, and depression scales of the Crown-Crisp experiential index. In contrast the "no trauma" group scored more specifically highly on the anxiety scale, along with major trends to high depression and hysteria scale scores. Two cases are presented which illustrate exceptional occurrence of later onset of sleepwalking/night terrors with accompanying post-traumatic symptoms during wakefulness. It is concluded that a history of major psychological trauma exists in only a minority of adult patients presenting with sleepwalking/night terror syndrome. In this subgroup trauma appears to dictate the subsequent content of the attacks. However, the symptoms express themselves within the form of the sleepwalking/night terror syndrome rather than as rapid eye movement sleep related nightmares. The main group of subjects with the syndrome and with no history of major psychological trauma show no clinical or DIS-Q evidence of dissociation during wakefulness. The proposition that, within the character structure of this group, the mechanism still operates but exclusively within sleep remains a possibility.


Keywords: sleepwalking; night terrors; dissociation; post-traumatic stress disorder PMID:11264487

Dissociative Experiences and Anger Proneness in Late Adolescent Females with Different Attachment Styles.

ERIC Educational Resources Information Center

Calamari, Elena; Pini, Mauro

2003-01-01

Study investigated the relationships between dissociative experiences, anger proneness, and attachment styles in a nonclinical sample of late adolescent females. Found a connection between anger proneness and dissociation. Insecurely attached females showed more anger proneness. Results confirm the importance of psychological intervention for…

Ataque de nervios: relationship to anxiety sensitivity and dissociation predisposition.

PubMed

Hinton, Devon E; Chong, Roberto; Pollack, Mark H; Barlow, David H; McNally, Richard J

2008-01-01

We investigated the relative importance of "fear of arousal symptoms" (i.e., anxiety sensitivity) and "dissociation tendency" in generating ataque de nervios. Puerto Rican patients attending an outpatient psychiatric clinic were assessed for ataque de nervios frequency in the previous month, and they completed the Anxiety Sensitivity Index (ASI) and the Dissociation Experiences Scale (DES). ASI scores were especially high in the ataque-positive group (M=41.6, SD=12.8) as compared with the ataque-negative group (M=27.2, SD=11.7), t(2, 68)=4.6, P<.001. Among the whole sample (N=70), in a logistic regression analysis, the ASI significantly predicted (odds ratio=2.6) the presence of ataque de nervios, but the DES did not. In a linear regression analysis, ataque severity was significantly predicted by both the ASI (beta=.46) and the DES (beta=.29). The theoretical and clinical implications of the strong relationship of the ASI to ataque severity are discussed.

Ethane-xenon mixtures under shock conditions

DOE PAGES

Magyar, Rudolph J.; Root, Seth; Mattsson, Thomas; ...

2015-04-22

Mixtures of light elements with heavy elements are important in inertial confinement fusion. We explore the physics of molecular scale mixing through a validation study of equation of state (EOS) properties. Density functional theory molecular dynamics (DFT-MD) at elevated temperature and pressure is used to obtain the thermodynamic state properties of pure xenon, ethane, and various compressed mixture compositions along their principal Hugoniots. In order to validate these simulations, we have performed shock compression experiments using the Sandia Z-Machine. A bond tracking analysis correlates the sharp rise in the Hugoniot curve with the completion of dissociation in ethane. Furthermore, themore » DFT-based simulation results compare well with the experimental data along the principal Hugoniots and are used to provide insight into the dissociation and temperature along the Hugoniots as a function of mixture composition. Interestingly, we find that the compression ratio for complete dissociation is similar for several compositions suggesting a limiting compression for C-C bonded systems.« less

Depression and dissociation as predictors of physical health symptoms among female rape survivors with posttraumatic stress disorder.

PubMed

Scioli-Salter, Erica R; Johnides, Benjamin D; Mitchell, Karen S; Smith, Brian N; Resick, Patricia A; Rasmusson, Ann M

2016-09-01

To investigate the relative contributions of depression and dissociation, as well as posttraumatic stress disorder (PTSD), to physical health symptoms and to examine the relationships among somatic symptoms, PTSD, depression, and dissociation in relation to childhood and adult trauma exposure. Cross-sectional data are from 132 female rape survivors with PTSD assessed before engaging in a study of trauma-focused cognitive therapy for PTSD. Measures included the Pennebaker Inventory of Limbic Languidness, Clinician Administered PTSD Scale, Beck Depression Inventory, Trauma Symptom Inventory-Dissociation Subscale, Childhood Sexual Abuse Exposure Questionnaire, and Assessing Environments-III-Physical Punishment Scale. Hierarchical regression analyses revealed that only dissociative and depression symptoms contributed significantly to physical health symptoms. Similarly, among the subsample of women with either childhood sexual or physical abuse, depression and dissociation were significant predictors of somatic symptoms. However, among women without childhood abuse, only dissociation significantly predicted somatic symptoms. Understanding the psychological and biological mechanisms that link childhood versus adult trauma exposure, PTSD, and comorbid depression or dissociation to physical health symptoms may aid development of individualized treatments for the physical and psychological consequences of trauma. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Depression and Dissociation as Predictors of Physical Health Symptoms Among Female Rape Survivors with PTSD

PubMed Central

Scioli-Salter, Erica R.; Johnides, Benjamin D.; Mitchell, Karen S.; Smith, Brian N.; Resick, Patricia A.; Rasmusson, Ann M.

2016-01-01

Objective To investigate the relative contributions of depression and dissociation, as well as PTSD, to physical health symptoms and to examine the relationships among somatic symptoms, PTSD, depression, and dissociation in relation to childhood and adult trauma exposure. Method Cross-sectional data are from 132 female rape survivors with PTSD assessed prior to engaging in a study of trauma-focused cognitive therapy for PTSD. Measures included the Pennebaker Inventory of Limbic Languidness, Clinician Administered PTSD Scale, Beck Depression Inventory, Trauma Symptom Inventory-Dissociation Subscale, Childhood Sexual Abuse Exposure Questionnaire, and Assessing Environments-III-Physical Punishment Scale. Results Hierarchical regression analyses revealed that only dissociative and depression symptoms contributed significantly to physical health symptoms. Similarly, among the subsample of women with either childhood sexual or physical abuse, depression and dissociation were significant predictors of somatic symptoms. However, among women without childhood abuse, only dissociation significantly predicted somatic symptoms. Conclusion Understanding the psychological and biological mechanisms that link childhood versus adult trauma exposure, PTSD, and comorbid depression or dissociation to physical health symptoms may aid development of individualized treatments for the physical and psychological consequences of trauma. PMID:27149157

Dissociative recombination of the ground state of N2(+)

NASA Technical Reports Server (NTRS)

Guberman, Steven L.

1991-01-01

Large-scale calculations of the dissociative recombination cross sections and rates for the v = 0 level of the N2(+) ground state are reported, and the important role played by vibrationally excited Rydberg states lying both below and above the v = 0 level of the ion is demonstrated. The large-scale electronic wave function calculations were done using triple zeta plus polarization nuclear-centered-valence Gaussian basis sets. The electronic widths were obtained using smaller wave functions, and the cross sections were calculated on the basis of the multichannel quantum defect theory. The DR rate is calculated at 1.6 x 10 to the -7th x (Te/300) to the -0.37 cu cm/sec for Te in the range of 100 to 1000 K, and is found to be in excellent agreement with prior microwave afterglow experiments but in disagreement with recent merged beam results. It is inferred that the dominant mechanism for DR imparts sufficient energy to the product atoms to allow for escape from the Martian atmosphere.

Thermal dissociation and relaxation in vinyl fluoride, 1,1-difluoroethane and 1,3,5-triazine

NASA Astrophysics Data System (ADS)

Xu, Hui

This study reports measurements of the thermal dissociation of 1,1-difluoroethane in the shock tube. The experiments employ laser schlieren measurements of rate for the dominant HF elimination using 10% 1,1-difluoroethane in Kr over 1500--2000 K and 43 < P < 424 torr. The product vinyl then dissociates affecting the late density gradient. We include a laser schlieren study (1717--2332 K, 75 < P < 482 torr in 10% and 4% vinyl fluoride in Kr) of this dissociation. This latter work also includes a set of experiments using shock-tube time-of-flight mass-spectrometry (4% vinyl fluoride in neon, 1500--1980 K, 500 < P < 1300 torr), which confirm the theoretical expectation that the only reaction in vinyl fluoride is HF elimination. The relaxation experiments (1--20% C2H3F in Kr, 415--1975 K, 5 < P < 50 torr, and 2% and 5% C2H4F2 in Kr, 700--1350 K, 6 < P < 22 torr) exhibit very rapid relaxation, and incubation delays should be negligible in dissociation. A RRKM model of dissociation in 1,1-difluoroethane based on a G3B3 calculation of barrier and other properties fits the experiments but requires a very large down of 1600cm-1 . Dissociation of vinyl fluoride has two parallel HF eliminations both three-center and four-center with nearly equal barriers. An RRKM fit to the observed falloff again requires an unusually large down and the experiments actually support a slightly reduced barrier. Both 1,3,5-triazine and pyrazine relax extremely rapidly with energy transfer in a few collisions, any incubation delay can be confidently discounted in dissociation. 1,3,5-triazine dissociation experiments show fall-off with a clear pressure dependence. The three body product dissociation mechanism models this dissociation perfectly. Experimental data agree well with an RRKM calculation using a down of 1200cm-1 and a barrier E0 = 84.66 kcal/mol. Dyakov et al. suggested lower barrier of E0 = 81 kcal/mole. The new RRKM calculation using this barrier seems a better fit to the experiments. The falloff is now fit well with a down of the more usual form 126(T/298) 0-9 cm-1.

The contributions of interpersonal trauma exposure and world assumptions to predicting dissociation in undergraduates.

PubMed

Lilly, Michelle M

2011-01-01

This study examines the relationship between world assumptions and trauma history in predicting symptoms of dissociation. It was proposed that cognitions related to the safety and benevolence of the world, as well as self-worth, would be related to the presence of dissociative symptoms, the latter of which were theorized to defend against threats to one's sense of safety, meaningfulness, and self-worth. Undergraduates from a midwestern university completed the Multiscale Dissociation Inventory, World Assumptions Scale, and Traumatic Life Events Questionnaire. Consistent with the hypotheses, world assumptions were related to the extent of trauma exposure and interpersonal trauma exposure in the sample but were not significantly related to non-interpersonal trauma exposure. World assumptions acted as a significant partial mediator of the relationship between trauma exposure and dissociation, and this relationship held when interpersonal trauma exposure specifically was considered. The factor structures of dissociation and world assumptions were also examined using principal component analysis, with the benevolence and self-worth factors of the World Assumptions Scale showing the strongest relationships with trauma exposure and dissociation. Clinical implications are discussed.

PTSD, emotion dysregulation, and dissociative symptoms in a highly traumatized sample

PubMed Central

Powers, Abigail; Cross, Dorthie; Fani, Negar; Bradley, Bekh

2015-01-01

Exposure to multiple traumas has been shown to result in many negative mental health outcomes, including posttraumatic stress disorder (PTSD). Dissociation, which involves disruptions in memory, identity, and perceptions, may be a component of PTSD, particularly among individuals who have experienced childhood trauma. Emotion regulation difficulties are also strongly associated with childhood trauma and emotion dysregulation may be a particularly important factor to consider in the development and maintenance of dissociative symptoms. The goal of the present study was to determine whether emotion dysregulation mediated the relationship between PTSD symptoms and dissociation in a sample of 154 (80% female, 97% African-American) adults recruited from a public, urban hospital. PTSD was measured using the Clinician Administered PTSD Scale, emotion dysregulation was measured using the Difficulties in Emotion Regulation Scale, and dissociation was measured using the Multiscale Dissociation Inventory. A linear regression analysis showed that both PTSD and emotion dysregulation were statistically significant predictors of dissociation even after controlling for trauma exposure. Alexithymia and an inability to use emotion regulation strategies in particular were predictive of dissociation above and beyond other predictor variables. Using bootstrapping techniques, we found that overall emotion dyregulation partially mediated the effect of PTSD symptoms on dissociative symptoms. Our results suggest that emotion dysregulation may be important in understanding the relation between PTSD and dissociative symptoms. Treatment approaches may consider a focus on training in emotional understanding and the development of adaptive regulation strategies as a way to address dissociative symptoms in PTSD patients. PMID:25573648

Impact of an Adlerian Based Pretrial Diversion Program: Self Concept and Dissociation

ERIC Educational Resources Information Center

Norvell, Jeanell J.

2010-01-01

Clients' self concepts and dissociative experiences were examined to determine the impact of an Adlerian based pretrial diversion program. Clients completing the program displayed a significant change in self concepts and dissociative experiences. A repeated measures multivariate analysis of variance indicated a 35% change, made up of the…

Characteristics of self-cutters among male inmates: association with bulimia and dissociation.

PubMed

Matsumoto, Toshihiko; Yamaguchi, Akiko; Asami, Takeshi; Okada, Takayuki; Yoshikawa, Kazuo; Hirayasu, Yoshio

2005-06-01

It was examined whether bulimia and dissociation are common in male self-cutters, as has been found in female self-cutters. The subjects were 796 male inmates of a juvenile prison. A self-reporting questionnaire was used to assess self-cutting, histories of psychoactive substance use, problem behaviors, and traumatic life events in the subjects. The Adolescent Dissociative Experience Scale and the Bulimia Investigatory Test of Edinburgh were also used. Subjects were divided into two groups: self-cutting and non-cutting. Questionnaire responses and dissociation and bulimia assessments were compared between the groups. Self-cutters began smoking (P < 0.001) and drinking (P < 0.001) earlier, and more frequently used illicit psychoactive drugs (P < 0.001), experienced childhood physical abuse (P < 0.001), and reported suicide attempts (P < 0.001), suicidal ideation (P < 0.001), and outward violence toward a person (P < 0.001) or object (P < 0.001) than non-cutters. Self-cutters also scored significantly higher on the bulimia (P < 0.001) and dissociation tests (P < 0.001). Logistic regression analysis demonstrated that suicide attempt (odds ratio, 4.311) and suicidal ideation (odds ratio, 2.336) could discriminate between male inmates with and without self-cutting. Male self-cutters showed 'multi-impulsive bulimic' tendencies resembling those of female self-cutters, although to a lesser extent. Clinical features of male as opposed to female self-cutters were influenced by gender differences.

The Effects of Sleep Deprivation on Dissociation and Profiles of Mood, and Its Association with Biochemical Changes

PubMed Central

SELVİ, Yavuz; KILIÇ, Sultan; AYDIN, Adem; GÜZEL ÖZDEMİR, Pınar

2015-01-01

Introduction Sleep deprivation is a method, which has being used in order to comprehend the functions of sleep both in healthy individuals and for the patients of depression with in treatment, for a long time. The objective of our present study is to examine the relation between hormonal values, which are known for being related to the effects of these said changes determined in the mood, dissociation and thought suppression in healthy individuals after one night of sleep deprivation implementation. Methods One night sleep deprivation was performed on a total of thirty-two healthy volunteers (16 males and 16 females) who were included in the study. Blood samples were taken from the individuals before and after sleep deprivation implementation in order to determine cortisol, dehydroepiandrosterone-sulfate (DHEA-S) and Thyroid Functions’ Levels tests. In order to evaluate the effects of the sleep deprivation on moods, “White Bear Suppression Inventory (WBSI)” has been conducted, with an aim of evaluating thought suppression, “Profile of Mood States (POMS)”, “Dissociative Experiences Scale (DES)” with a purpose of realizing any dissociation tendency. Results On the individuals who have been implemented for sleep deprivation, a decrease on depression and vigor-activity sub-scales values was detected, and an increase was determined on fatigue sub-scales values of “POMS”. While the values of DES were found to have been statistically increased after sleep deprivation, also a significant decrease was determined on WBSI values. Even if there hasn’t been any significant statistical change determined on cortisol levels after sleep deprivation, yet there had been some significant changes detected on Thyroid Stimulating Hormone (TSH), fT3, fT4, and DHEA-S levels. Decrease in “POMS” depression sub-scale values and increase on fatigue sub-scale values were determined on the individuals whose sT4 levels were found to be increased significantly in statistic manner after the sleep deprivation. Conclusion According to the results of our study, sleep deprivation for one night was determined to cause decrease on depressive mood, increase on dissociative symptoms and to lower the tendency of suppressing the unwanted thoughts, consciously. The fact of being obtained lower depression values, on the individuals with the increased DHEA-S levels after the sleep deprivation meets with the information claiming that the high DHEA-S levels may be deemed as protectors against the negative effects of the stress. PMID:28360682

Trait dissociation and commission errors in memory reports of emotional events.

PubMed

Merckelbach, Harald; Zeles, Gwen; Van Bergen, Saskia; Giesbrecht, Timo

2007-01-01

In 2 studies we examined whether trait dissociation is related to spontaneous commission errors (reports of events that did not occur) in free recall of emotional events. We also explored whether the functional locus of the dissociation-commission link is related to repeated retrieval or shallow encoding. In Experiment 1 participants were exposed to a staged incident and were repeatedly asked to add more information to their written accounts of the event. Dissociation levels were related to commission errors, indicating that people who report many dissociative experiences tend to make more commission errors. However, it was not the case that the overall increase in commission errors over successive retrieval attempts was typical for high dissociative participants. In Experiment 2 participants saw a video fragment of a severe car accident. During the video, half the participants performed a dual task, and the other half did not. Participants performing the dual task made more commission errors than controls, but this effect was not more pronounced in those with high trait dissociation scores. These studies show that there is a link between dissociation and spontaneous commission errors in memory reports of emotional events, but the functional locus of this link remains unclear.

The Dissociative Subtype of PTSD Scale (DSPS): Initial Evaluation in a National Sample of Trauma-Exposed Veterans

PubMed Central

Wolf, Erika J.; Mitchell, Karen S.; Sadeh, Naomi; Hein, Christina; Fuhrman, Isaac; Pietrzak, Robert H.; Miller, Mark W.

2015-01-01

The fifth edition of the Diagnostic and Statistical Manual (DSM-5) includes a dissociative subtype of posttraumatic stress disorder (PTSD), but no existing measures specifically assess it. This paper describes the initial evaluation of a 15-item self-report measure of the subtype called the Dissociative Subtype of PTSD Scale (DSPS) in an on-line survey of 697 trauma-exposed military veterans representative of the US veteran population. Exploratory factor analyses of the lifetime DSPS items supported the intended structure of the measure consisting of three factors reflecting derealization/depersonalization, loss of awareness, and psychogenic amnesia. Consistent with prior research, latent profile analyses assigned 8.3% of the sample to a highly dissociative class distinguished by pronounced symptoms of derealization and depersonalization. Overall, results provide initial psychometric support for the lifetime DSPS scales; additional research in clinical and community samples is needed to further validate the measure. PMID:26603115

The Dissociative Subtype of PTSD Scale: Initial Evaluation in a National Sample of Trauma-Exposed Veterans.

PubMed

Wolf, Erika J; Mitchell, Karen S; Sadeh, Naomi; Hein, Christina; Fuhrman, Isaac; Pietrzak, Robert H; Miller, Mark W

2017-06-01

The fifth edition of the Diagnostic and Statistical Manual includes a dissociative subtype of posttraumatic stress disorder, but no existing measures specifically assess it. This article describes the initial evaluation of a 15-item self-report measure of the subtype called the Dissociative Subtype of Posttraumatic Stress Disorder Scale (DSPS) in an online survey of 697 trauma-exposed military veterans representative of the U.S. veteran population. Exploratory factor analyses of the lifetime DSPS items supported the intended structure of the measure consisting of three factors reflecting derealization/depersonalization, loss of awareness, and psychogenic amnesia. Consistent with prior research, latent profile analyses assigned 8.3% of the sample to a highly dissociative class distinguished by pronounced symptoms of derealization and depersonalization. Overall, results provide initial psychometric support for the lifetime DSPS scales; additional research in clinical and community samples is needed to further validate the measure.

Demonstration of a 100-kWth high-temperature solar thermochemical reactor pilot plant for ZnO dissociation

NASA Astrophysics Data System (ADS)

Koepf, E.; Villasmil, W.; Meier, A.

2016-05-01

Solar thermochemical H2O and CO2 splitting is a viable pathway towards sustainable and large-scale production of synthetic fuels. A reactor pilot plant for the solar-driven thermal dissociation of ZnO into metallic Zn has been successfully developed at the Paul Scherrer Institute (PSI). Promising experimental results from the 100-kWth ZnO pilot plant were obtained in 2014 during two prolonged experimental campaigns in a high flux solar simulator at PSI and a 1-MW solar furnace in Odeillo, France. Between March and June the pilot plant was mounted in the solar simulator and in-situ flow-visualization experiments were conducted in order to prevent particle-laden fluid flows near the window from attenuating transparency by blocking incoming radiation. Window flow patterns were successfully characterized, and it was demonstrated that particle transport could be controlled and suppressed completely. These results enabled the successful operation of the reactor between August and October when on-sun experiments were conducted in the solar furnace in order to demonstrate the pilot plant technology and characterize its performance. The reactor was operated for over 97 hours at temperatures as high as 2064 K; over 28 kg of ZnO was dissociated at reaction rates as high as 28 g/min.

Cognitive processes in dissociation: an analysis of core theoretical assumptions.

PubMed

Giesbrecht, Timo; Lynn, Steven Jay; Lilienfeld, Scott O; Merckelbach, Harald

2008-09-01

Dissociation is typically defined as the lack of normal integration of thoughts, feelings, and experiences into consciousness and memory. The present article critically evaluates the research literature on cognitive processes in dissociation. The authors' review indicates that dissociation is characterized by subtle deficits in neuropsychological performance (e.g., heightened distractibility). Some of the cognitive phenomena (e.g., weakened cognitive inhibition) associated with dissociation appear to be dependent on the emotional or attentional context. Contrary to a widespread assumption in the clinical literature, dissociation does not appear to be related to avoidant information processing. Rather, it is associated with an enhanced propensity toward pseudo-memories, possibly mediated by heightened levels of interrogative suggestibility, fantasy proneness, and cognitive failures. Evidence for a link between dissociation and either memory fragmentation or early trauma based on objective measures is conspicuously lacking. The authors identify a variety of methodological issues and discrepancies that make it difficult to articulate a comprehensive framework for cognitive mechanisms in dissociation. The authors conclude with a discussion of research domains (e.g., sleep-related experiences, drug-related dissociation) that promise to advance our understanding of cognition and dissociation.

Childhood trauma and dissociation in patients with alcohol dependence, drug dependence, or both-A multi-center study.

PubMed

Schäfer, Ingo; Langeland, Willemien; Hissbach, Johanna; Luedecke, Christel; Ohlmeier, Martin D; Chodzinski, Claudia; Kemper, Ulrich; Keiper, Peter; Wedekind, Dirk; Havemann-Reinecke, Ursula; Teunissen, Sybille; Weirich, Steffen; Driessen, Martin

2010-06-01

The aims of this study were to examine the level of dissociative symptoms in patients with different substance related disorders (alcohol dependence, drug dependence, and combined alcohol and drug dependence), and to investigate the influence of potentially traumatic events in childhood, age, gender, and posttraumatic stress disorder on the relationship between dissociative symptoms and type of substance abuse. Of the 459 participants (59.7% male) 182 (39.7%) were alcohol-dependent (A), 154 (33.6%) were drug-dependent (D), and 123 (26.8%) were dependent on both, alcohol and drugs (AD) based on the DSM-IV criteria for a current diagnosis. Participants completed the Childhood Trauma Questionnaire (CTQ) and the Dissociative Experiences Scale (DES). The International Diagnostics Checklist (IDCL) was administered to diagnose PTSD. Higher levels of dissociation were observed in patients with drug dependence as compared to patients with mere alcohol dependence (mean DES group A: 9.9+/-8.8; group D: 12.9+/-11.7; group AD: 15.1+/-11.3). However, when severity of potentially traumatic events in childhood, PTSD, age and gender were included in the analysis, the influence of the type of substance abuse did not prove to be statistically significant. The variable most strongly related to dissociative symptoms was severity of potentially traumatic events in childhood, in particular emotional abuse, even after controlling for PTSD and other potential confounders. It seems appropriate to screen SUD patients for dissociative symptoms, especially those with a more complex risk profile including (additional) drug abuse, female gender, younger age and most importantly a history of childhood trauma. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

Trauma, posttraumatic stress disorder symptoms, and dissociative experiences during men's intimate partner violence perpetration.

PubMed

LaMotte, Adam D; Murphy, Christopher M

2017-09-01

Research with partner-violent men has found that a subset of this population reports dissociative experiences during their violence (e.g., inability to remember violence [despite admission that it had occurred]; flashbacks during violence). However, the literature examining this phenomenon has been primarily limited to clinical observations and case studies, and there is a need for more thorough empirical investigation regarding the prevalence and correlates of dissociative violence among individuals in intimate partner violence (IPV) intervention programs. The primary goals of this study were to provide descriptive information about the rates of endorsement of dissociative experiences during IPV perpetration and to examine their associations with trauma exposure and posttraumatic stress disorder (PTSD) symptoms. Participants were 302 men presenting for services at a community-based IPV intervention program. All variables were assessed via self-report and clinician interview at program intake. Results indicated that 22.2% of participants reported 1 or more dissociative experiences during partner violence perpetration. Additionally, frequency of dissociative IPV perpetration showed significant positive correlations with the total number of potentially traumatic events (PTEs) reported and PTSD symptoms, with effect sizes in the small and medium ranges of magnitude, respectively. Finally, PTSD symptoms significantly mediated the relationship between total number of PTEs and dissociative IPV perpetration. Findings indicate a potentially meaningful relationship between trauma, PTSD symptoms, and dissociative experiences during IPV perpetration. Further qualitative and quantitative investigation is needed to better understand this phenomenon and how it can be addressed in IPV treatment. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Comparative study of the dissociation energies of Ni2 and Ni2(+)

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Langhoff, Stephen R.

1992-01-01

Computations at the internally contracted averaged coupled-pair-functional level of theory yield a dissociation energy (Do) for Ni2(+) that is 0.17 eV larger than that of Ni2. This finding is consistent with the collision-induced dissociation experiments of Lian, Su, and Armentrout, but rules out the results from the resonant two-photon dissociation experiments of Lessen and Brucat, which predict that the Do value of Ni2(+) is about 1 eV larger than that of Ni2.

Conversion Disorder Comorbidity and Childhood Trauma.

PubMed

Akyüz, Fatma; Gökalp, Peykan G; Erdiman, Sezgin; Oflaz, Serap; Karşidağ, Çağatay

2017-03-01

The aim of this study is to examine the socio-demographic and clinical characteristics, the presence of comorbidity, and the link with childhood traumatic experiences in patients with conversion disorder (CD) in a psychiatric outpatient clinic. A total of 60 literate, female patients between 18 and 65 years of age who were referred to the general psychiatry outpatient clinic and who were diagnosed with conversion disorder according to the DSM-IV diagnostic criteria were included in the study. A questionnaire on sociodemographic and clinical characteristics, the Brief Psychiatric Rating Scale (BPRS), the Hamilton Depression Rating Scale (HDRS), the Hamilton Anxiety Rating Scale (HARS), the Childhood Trauma Questionnaire (CTQ), and the Dissociative Events Scale (DES) were used to assess the cases. The mean age of the participants was 36.27±11.18 years. 72% of the patients were married and 63% were primary school graduates. The most common symptoms were asthenia (100%), aphasia (96.7%), and crying-convulsions (93%). The most common co-morbidities were depression (50%) and dissociative disorders (48.3%). Among the patients, 53.3% reported a history of exposure to physical violence and 25% reported a history of sexual assault in childhood. Assessment of the Childhood Traumatic Questionnaire revealed a significant positive relation between emotional, physical, and sexual abuse scores and DES score. CD has not yet been fully analyzed in detail in health institutions; co-existence of another mental disorder and the presence of traumatic experiences in the past further complicate the issue. Consideration of these factors during treatment will have a positive impact on the course and prognosis of the disorder.

Postintensive care unit psychological burden in patients with chronic obstructive pulmonary disease and informal caregivers: A multicenter study.

PubMed

de Miranda, Sandra; Pochard, Frédéric; Chaize, Marine; Megarbane, Bruno; Cuvelier, Antoine; Bele, Nicolas; Gonzalez-Bermejo, Jesus; Aboab, Jérome; Lautrette, Alexandre; Lemiale, Virginie; Roche, Nicolas; Thirion, Marina; Chevret, Sylvie; Schlemmer, Benoit; Similowski, Thomas; Azoulay, Elie

2011-01-01

To determine the prevalence and risk factors of symptoms of anxiety, depression, and posttraumatic stress disorder-related symptoms in patients with chronic obstructive pulmonary disease and their relatives after an intensive care unit stay. Prospective multicenter study. Nineteen French intensive care units. One hundred twenty-six patients with chronic obstructive pulmonary disease who survived an intensive care unit stay and 102 relatives. None. Patients and relatives were interviewed at intensive care unit discharge and 90 days later to assess symptoms of anxiety and depression using Hospital Anxiety and Depression Scale (HADS) and posttraumatic stress disorder-related symptoms using the Impact of Event Scale (IES). At intensive care unit discharge, 90% of patients recollected traumatic psychological events in the intensive care unit. At day 90, we were able to conduct telephone interviews with 53 patients and 47 relatives. Hospital Anxiety and Depression Scale scores indicated symptoms of anxiety and depression in 52% and 45.5% of patients at intensive care unit discharge and in 28.3% and 18.9% on day 90, respectively. Corresponding prevalence in relatives were 72.2% and 25.7% at intensive care unit discharge and 40.4% and 14.9% on day 90, respectively. The Impact of Event Scale indicated posttraumatic stress disorder-related symptoms in 20.7% of patients and 29.8% of relatives on day 90. Peritraumatic dissociation assessed using the Peritraumatic Dissociative Experiences Questionnaire was independently associated with posttraumatic stress disorder-related symptoms in the patients and relatives. Previous intensive care unit experience and recollection of bothersome noise in the intensive care unit predicted posttraumatic stress disorder-related symptoms in the patients. Psychiatric symptoms were found to be common in a group of 126 patients with chronic obstructive pulmonary disease who survived an intensive care unit stay and their relatives at intensive care unit discharge and 90 days later. Peritraumatic dissociation at intensive care unit discharge was found to independently predict posttraumatic stress disorder-related symptoms in this sample of patients and relatives.

Shock tube study of dissociation and relaxation in 1,1-difluoroethane and vinyl fluoride.

PubMed

Xu, Hui; Kiefer, John H; Sivaramakrishnan, Raghu; Giri, Binod R; Tranter, Robert S

2007-08-21

This paper reports measurements of the thermal dissociation of 1,1-difluoroethane in the shock tube. The experiments employ laser-schlieren measurements of rate for the dominant HF elimination using 10% 1,1-difluoroethane in Kr over 1500-2000 K and 43 < P < 424 torr. The vinyl fluoride product of this process then dissociates affecting the late observations. We thus include a laser schlieren study (1717-2332 K, 75 < P < 482 torr in 10 and 4% vinyl fluoride in Kr) of this dissociation. This latter work also includes a set of experiments using shock-tube time-of-flight mass spectrometry (4% vinyl fluoride in neon, 1500-1980 K, 500 < P < 1300 torr). These time-of-flight experiments confirm the theoretical expectation that the only reaction in vinyl fluoride is HF elimination. The dissociation experiments are augmented by laser schlieren measurements of vibrational relaxation (1-20% C(2)H(3)F in Kr, 415-1975 K, 5 < P < 50 torr, and 2 and 5% C(2)H(4)F(2) in Kr, 700-1350 K, 6 < P < 22 torr). These experiments exhibit very rapid relaxation, and incubation delays should be negligible in dissociation. An RRKM model of dissociation in 1,1-difluoroethane based on a G3B3 calculation of barrier and other properties fits the experiments but requires a very large DeltaE(down) of 1600 cm(-1), similar to that found in a previous examination of 1,1,1-trifluoroethane. Dissociation of vinyl fluoride is complicated by the presence of two parallel HF eliminations, both three-center and four-center. Structure calculations find nearly equal barriers for these, and TST calculations show almost identical k(infinity). An RRKM fit to the observed falloff again requires an unusually large DeltaE(down) and the experiments actually support a slightly reduced barrier. These large energy-transfer parameters now seem routine in these large fluorinated species. It is perhaps a surprising result for which there is as yet no explanation.

Post-traumatic stress disorder and major depression among Italian Nazi concentration camp survivors: a controlled study 50 years later.

PubMed

Favaro, A; Rodella, F C; Colombo, G; Santonastaso, P

1999-01-01

The study aimed to assess the current and lifetime rates of post-traumatic stress disorder (PTSD) and major depression (MDD) among Nazi concentration camps survivors. We investigated 51 Italian political deportees and 47 Resistance Movement veterans who reported traumatic experiences during active service. The Structured Clinical Interview for DSM-IV was used to assess the presence of PTSD and MDD. The Dissociative Experiences Scale and the shorter version of the Hopkins Symptoms Checklist were also administered. The lifetime rates of PTSD and MDD were 35.3% and 45.1% respectively among deportees and 4.3% and 6.4% among former partisans. The current rates for PTSD and MDD were 25.5% and 33.3% among deportees and 4.3% and 4.3% among former partisans. Dissociative symptoms were more severe among deportees than among Resistance movement veterans. Concentration camp internment, even for political reasons, appears to have severe long-term psychiatric consequences.

Fiber optic sensing technology for detecting gas hydrate formation and decomposition.

PubMed

Rawn, C J; Leeman, J R; Ulrich, S M; Alford, J E; Phelps, T J; Madden, M E

2011-02-01

A fiber optic-based distributed sensing system (DSS) has been integrated with a large volume (72 l) pressure vessel providing high spatial resolution, time-resolved, 3D measurement of hybrid temperature-strain (TS) values within experimental sediment-gas hydrate systems. Areas of gas hydrate formation (exothermic) and decomposition (endothermic) can be characterized through this proxy by time series analysis of discrete data points collected along the length of optical fibers placed within a sediment system. Data are visualized as an animation of TS values along the length of each fiber over time. Experiments conducted in the Seafloor Process Simulator at Oak Ridge National Laboratory clearly indicate hydrate formation and dissociation events at expected pressure-temperature conditions given the thermodynamics of the CH(4)-H(2)O system. The high spatial resolution achieved with fiber optic technology makes the DSS a useful tool for visualizing time-resolved formation and dissociation of gas hydrates in large-scale sediment experiments.

Fiber optic sensing technology for detecting gas hydrate formation and decomposition

NASA Astrophysics Data System (ADS)

Rawn, C. J.; Leeman, J. R.; Ulrich, S. M.; Alford, J. E.; Phelps, T. J.; Madden, M. E.

2011-02-01

A fiber optic-based distributed sensing system (DSS) has been integrated with a large volume (72 l) pressure vessel providing high spatial resolution, time-resolved, 3D measurement of hybrid temperature-strain (TS) values within experimental sediment-gas hydrate systems. Areas of gas hydrate formation (exothermic) and decomposition (endothermic) can be characterized through this proxy by time series analysis of discrete data points collected along the length of optical fibers placed within a sediment system. Data are visualized as an animation of TS values along the length of each fiber over time. Experiments conducted in the Seafloor Process Simulator at Oak Ridge National Laboratory clearly indicate hydrate formation and dissociation events at expected pressure-temperature conditions given the thermodynamics of the CH4-H2O system. The high spatial resolution achieved with fiber optic technology makes the DSS a useful tool for visualizing time-resolved formation and dissociation of gas hydrates in large-scale sediment experiments.

Peritraumatic dissociation and physiological response to trauma-relevant stimuli in Vietnam combat veterans with posttraumatic stress disorder.

PubMed

Kaufman, Milissa L; Kimble, Matthew O; Kaloupek, Danny G; McTeague, Lisa M; Bachrach, Peter; Forti, Allison M; Keane, Terence M

2002-03-01

A recent study found that female rape victims with acute posttraumatic stress disorder (PTSD) who received a high score on the Peritraumatic Dissociative Experiences Questionnaire exhibited suppression of physiological responses during exposure to trauma-related stimuli. The goal of our present study was to test whether the same relationship holds true for male Vietnam combat veterans with chronic PTSD, using secondary analyses applied to data derived from a Veteran's Affairs Cooperative Study. Vietnam combat veterans (N = 1238) completed measures to establish combat-related PTSD diagnostic status, extent of PTSD-related symptomatic distress, and presence of dissociative symptoms during their most stressful combat-related experiences. Extreme subgroups of veterans with current PTSD were classified as either low dissociators (N = 118) or high dissociators (N = 256) based on an abbreviated version of the Peritraumatic Dissociative Experiences Questionnaire. Dependent variables reflected subjective distress along with heart rate, skin conductance, electromyographic, and blood pressure data when responding to neutral and trauma-related audiovisual and imagery presentations. Veterans in the current PTSD group had significantly higher dissociation scores than did veterans in the lifetime and never PTSD groups. Among veterans with current PTSD, high dissociators reported greater PTSD-related symptomatic distress than did low dissociators, but the groups did not differ with respect to physiological reactivity to the trauma-related laboratory presentations. Our results replicate the previously reported relationship between peritraumatic dissociation and PTSD status in Vietnam combat veterans. However, we found no association between peritraumatic dissociation and the extent of physiological responding to trauma-relevant cues in male veterans with chronic combat-related PTSD.

Relationship between Child Abuse History, Trauma, and Dissociation in Russian College Students

ERIC Educational Resources Information Center

Dalenberg, Constance J.; Palesh, Oxana Gronskaya

2004-01-01

Objective: The research was conducted to determine the relationship between violent trauma, child abuse history, and dissociative symptoms in a Russian population. Method: Three hundred and one undergraduate students from Moscow State Linguistics University participated in the study and completed the Dissociation Continuum Scale, the Violence…

Spatial resolution of gas hydrate and permeability changes from ERT data in LARS simulating the Mallik gas hydrate production test

NASA Astrophysics Data System (ADS)

Priegnitz, Mike; Thaler, Jan; Spangenberg, Erik; Schicks, Judith M.; Abendroth, Sven

2014-05-01

The German gas hydrate project SUGAR studies innovative methods and approaches to be applied in the production of methane from hydrate-bearing reservoirs. To enable laboratory studies in pilot scale, a large reservoir simulator (LARS) was realized allowing for the formation and dissociation of gas hydrates under simulated in-situ conditions. LARS is equipped with a series of sensors. This includes a cylindrical electrical resistance tomography (ERT) array composed of 25 electrode rings featuring 15 electrodes each. The high-resolution ERT array is used to monitor the spatial distribution of the electrical resistivity during hydrate formation and dissociation experiments over time. As the present phases of poorly conducting sediment, well conducting pore fluid, non-conducting hydrates, and isolating free gas cover a wide range of electrical properties, ERT measurements enable us to monitor the spatial distribution of these phases during the experiments. In order to investigate the hydrate dissociation and the resulting fluid flow, we simulated a hydrate production test in LARS that was based on the Mallik gas hydrate production test (see abstract Heeschen et al., this volume). At first, a hydrate phase was produced from methane saturated saline water. During the two months of gas hydrate production we measured the electrical properties within the sediment sample every four hours. These data were used to establish a routine estimating both the local degrees of hydrate saturation and the resulting local permeabilities in the sediment's pore space from the measured resistivity data. The final gas hydrate saturation filled 89.5% of the total pore space. During hydrate dissociation, ERT data do not allow for a quantitative determination of free gas and remaining gas hydrates since both phases are electrically isolating. However, changes are resolved in the spatial distribution of the conducting liquid and the isolating phase with gas being the only mobile isolating phase. Hence, it is possible to detect areas in the sediment sample where free gas is released due to hydrate dissociation and displaces the liquid phase. Combined with measurements and numerical simulation of the total two-phase fluxes from the sediment sample (see abstract Abendroth et al., this volume), the LARS experiments allow for detailed information on the dissociation process during hydrate production. Here we present the workflow and first results estimating local hydrate saturations and permeabilities during hydrate formation and the movement of liquid and gas phases during hydrate dissociation, respectively.

General Dissociation Scale and Hypnotizability with African American College Students.

ERIC Educational Resources Information Center

Sapp, Marty; Hitchcock, Kim

The purpose of this study was to assess the reliability of the General Dissociation Scale with African American college students, and provide additional data on how to assess hypnotizability with these students. Two-hundred and two undergraduate African American college students participated in this study. Students completed the HGSHS:A, a measure…

Effect of ketamine dose on self-rated dissociation in patients with treatment refractory anxiety disorders.

PubMed

Castle, Cameron; Gray, Andrew; Neehoff, Shona; Glue, Paul

2017-10-01

Patients receiving ketamine for refractory depression and anxiety report dissociative symptoms in the first 60 min post-dose. The most commonly used instrument to assess this is the Clinician-Administered Dissociative States Scale (CADSS), developed based on the assessment of patients with dissociative symptoms. Its psychometric properties for ketamine-induced dissociation have not been reported. We evaluated these from a study using 0.25-1 mg/kg ketamine and midazolam (as an active control) in 18 patients with treatment-resistant anxiety. Dissociation ratings were increased by ketamine in a dose-dependent manner. In contrast, midazolam showed no effect on ratings of dissociation. For individual CADSS items, the magnitude of change and the ketamine dose at which changes were observed were not homogenous. The Cronbach alpha for the total scale was high (0.937), with acceptable item-rest correlations for almost all individual items. Purposefully removing items to maximise alpha did not lead to meaningful improvements. Acceptable internal consistency was still observed after removing items which lacked evidence of responsiveness at lower doses. The high Cronbach alpha values identified in this study suggests that the CADSS is an internally consistent instrument for evaluating ketamine-induced dissociation in clinical trials in anxiety, although it does not capture symptoms such as thought disorder.

Dissociative Experience and Cultural Neuroscience: Narrative, Metaphor and Mechanism

PubMed Central

Kirmayer, Laurence J.

2016-01-01

Approaches to trance and possession in anthropology have tended to use outmoded models drawn from psychodynamic theory or treated such dissociative phenomena as purely discursive processes of attributing action and experience to agencies other than the self. Within psychology and psychiatry, understanding of dissociative disorders has been hindered by polemical “either/or” arguments: either dissociative disorders are real, spontaneous alterations in brain states that reflect basic neurobiological phenomena, or they are imaginary, socially constructed role performances dictated by interpersonal expectations, power dynamics and cultural scripts. In this paper, we outline an approach to dissociative phenomena, including trance, possession and spiritual and healing practices, that integrates the neuropsychological notions of underlying mechanism with sociocultural processes of the narrative construction and social presentation of the self. This integrative model, grounded in a cultural neuroscience, can advance ethnographic studies of dissociation and inform clinical approaches to dissociation through careful consideration of the impact of social context. PMID:18213511

Dissociative experience and cultural neuroscience: narrative, metaphor and mechanism.

PubMed

Seligman, Rebecca; Kirmayer, Laurence J

2008-03-01

Approaches to trance and possession in anthropology have tended to use outmoded models drawn from psychodynamic theory or treated such dissociative phenomena as purely discursive processes of attributing action and experience to agencies other than the self. Within psychology and psychiatry, understanding of dissociative disorders has been hindered by polemical "either/or" arguments: either dissociative disorders are real, spontaneous alterations in brain states that reflect basic neurobiological phenomena, or they are imaginary, socially constructed role performances dictated by interpersonal expectations, power dynamics and cultural scripts. In this paper, we outline an approach to dissociative phenomena, including trance, possession and spiritual and healing practices, that integrates the neuropsychological notions of underlying mechanism with sociocultural processes of the narrative construction and social presentation of the self. This integrative model, grounded in a cultural neuroscience, can advance ethnographic studies of dissociation and inform clinical approaches to dissociation through careful consideration of the impact of social context.

Anchoring the Gas-Phase Acidity Scale from Hydrogen Sulfide to Pyrrole. Experimental Bond Dissociation Energies of Nitromethane, Ethanethiol, and Cyclopentadiene.

PubMed

Ervin, Kent M; Nickel, Alex A; Lanorio, Jerry G; Ghale, Surja B

2015-07-16

A meta-analysis of experimental information from a variety of sources is combined with statistical thermodynamics calculations to refine the gas-phase acidity scale from hydrogen sulfide to pyrrole. The absolute acidities of hydrogen sulfide, methanethiol, and pyrrole are evaluated from literature R-H bond energies and radical electron affinities to anchor the scale. Relative acidities from proton-transfer equilibrium experiments are used in a local thermochemical network optimized by least-squares analysis to obtain absolute acidities of 14 additional acids in the region. Thermal enthalpy and entropy corrections are applied using molecular parameters from density functional theory, with explicit calculation of hindered rotor energy levels for torsional modes. The analysis reduces the uncertainties of the absolute acidities of the 14 acids to within ±1.2 to ±3.3 kJ/mol, expressed as estimates of the 95% confidence level. The experimental gas-phase acidities are compared with calculations, with generally good agreement. For nitromethane, ethanethiol, and cyclopentadiene, the refined acidities can be combined with electron affinities of the corresponding radicals from photoelectron spectroscopy to obtain improved values of the C-H or S-H bond dissociation energies, yielding D298(H-CH2NO2) = 423.5 ± 2.2 kJ mol(-1), D298(C2H5S-H) = 364.7 ± 2.2 kJ mol(-1), and D298(C5H5-H) = 347.4 ± 2.2 kJ mol(-1). These values represent the best-available experimental bond dissociation energies for these species.

Simulating the gas hydrate production test at Mallik using the pilot scale pressure reservoir LARS

NASA Astrophysics Data System (ADS)

Heeschen, Katja; Spangenberg, Erik; Schicks, Judith M.; Priegnitz, Mike; Giese, Ronny; Luzi-Helbing, Manja

2014-05-01

LARS, the LArge Reservoir Simulator, allows for one of the few pilot scale simulations of gas hydrate formation and dissociation under controlled conditions with a high resolution sensor network to enable the detection of spatial variations. It was designed and built within the German project SUGAR (submarine gas hydrate reservoirs) for sediment samples with a diameter of 0.45 m and a length of 1.3 m. During the project, LARS already served for a number of experiments simulating the production of gas from hydrate-bearing sediments using thermal stimulation and/or depressurization. The latest test simulated the methane production test from gas hydrate-bearing sediments at the Mallik test site, Canada, in 2008 (Uddin et al., 2011). Thus, the starting conditions of 11.5 MPa and 11°C and environmental parameters were set to fit the Mallik test site. The experimental gas hydrate saturation of 90% of the total pore volume (70 l) was slightly higher than volumes found in gas hydrate-bearing formations in the field (70 - 80%). However, the resulting permeability of a few millidarcy was comparable. The depressurization driven gas production at Mallik was conducted in three steps at 7.0 MPa - 5.0 MPa - 4.2 MPa all of which were used in the laboratory experiments. In the lab the pressure was controlled using a back pressure regulator while the confining pressure was stable. All but one of the 12 temperature sensors showed a rapid decrease in temperature throughout the sediment sample, which accompanied the pressure changes as a result of gas hydrate dissociation. During step 1 and 2 they continued up to the point where gas hydrate stability was regained. The pressure decreases and gas hydrate dissociation led to highly variable two phase fluid flow throughout the duration of the simulated production test. The flow rates were measured continuously (gas) and discontinuously (liquid), respectively. Next to being discussed here, both rates were used to verify a model of gas hydrate dissociation applying the foamy oil approach, a method earlier adopted to model the Mallik production test (see abstract Abendroth et al., this volume). Combined with a dense set of data from a cylindrical electrical resistance tomography (ERT) array (see abstract Priegnitz et al., this volume), very valuable information were gained on the spatial as well as temporal formation and dissociation of gas hydrates as well as changes in permeability and resulting pathways for the fluid flow. Here we present the set-up and execution of the experiment and discuss the results from temperature and flow measurements with respect to the gas hydrate dissociation and characteristics of resulting fluid flow. Uddin, M., Wright, F., and Coombe, D. 2011. Numerical Study of Gas Evolution and Transport Behaviours in Natural Gas-Hydrate Reservoirs. Journal of Canadian Petroleum Technology 50, 70-89.

The role of attachment in recovery after a school-shooting trauma.

PubMed

Turunen, Tuija; Haravuori, Henna; Punamäki, Raija-Leena; Suomalainen, Laura; Marttunen, Mauri

2014-01-01

Survivors of life-endangering trauma use varying resources that help them to recover. Attachment system activates in the times of distress, and is expected to associate with stress responses, arousal regulation, and mental health. We examined the associations of attachment style with posttraumatic stress disorders (PTSD) symptoms and dissociative symptoms, and posttraumatic growth (PTG) among students exposed to a school shooting in Finland in a three-wave follow-up setting. Participants were students (M age=24.9 years; 95% female) who were followed 4 (T1, N=236), 16 (T2, N=180), and 28 months (T3, N=137) after the shooting. The assessments included the Attachment Style Questionnaire, the Impact of Event Scale, part of the Adolescent Dissociative Experiences Scale and the Posttraumatic Growth Inventory. Securely attached survivors had lower levels of posttraumatic stress and dissociative symptoms than preoccupied at T1 and T2 as hypothesized. At T3 survivors with avoidant attachment style had higher levels of intrusive and hyperarousal symptoms than those with secure style. Concerning PTG, survivors with avoidant attachment style scored lower in PTG at T3 than survivors with both secure and preoccupied style. Secure attachment style was beneficial in trauma recovery. A challenge to the health care systems is to acknowledge that survivors with preoccupied and avoidant attachment styles react uniquely to trauma, and thus need help in different doses, modalities, and timings.

Cognitive Processes in Dissociation: An Analysis of Core Theoretical Assumptions

ERIC Educational Resources Information Center

Giesbrecht, Timo; Lilienfield, Scott O.; Lynn, Steven Jay; Merckelbach, Harald

2008-01-01

Dissociation is typically defined as the lack of normal integration of thoughts, feelings, and experiences into consciousness and memory. The present article critically evaluates the research literature on cognitive processes in dissociation. The authors' review indicates that dissociation is characterized by subtle deficits in neuropsychological…

Risk and protective factors of dissocial behavior in a probability sample.

PubMed

Moral de la Rubia, José; Ortiz Morales, Humberto

2012-07-01

The aims of this study were to know risk and protective factors for dissocial behavior keeping in mind that the self-report of dissocial behavior is biased by the impression management. A probability sample of adolescents that lived in two neighborhoods with high indexes of gangs and offenses (112 male and 86 women) was collected. The 27-item Dissocial Behavior Scale (ECODI27; Pacheco & Moral, 2010), Balanced Inventory of Desirable Responding, version 6 (BIDR-6; Paulhus, 1991), Sensation Seeking Scale, form V (SSS-V; Zuckerman, Eysenck, & Eysenck, 1978), Parent-Adolescent Communication Scale (PACS; Barnes & Olson, 1982), 30-item Rathus Assertiveness Schedule (RAS; Rathus, 1973), Interpersonal Reactivity Index (IRI; Davis, 1983) and a social relationship questionnaire (SRQ) were applied. Binary logistic regression was used for the data analysis. A third of the participants showed dissocial behavior. Belonging to a gang in the school (schooled adolescents) or to a gang out of school and job (total sample) and desinhibition were risk factors; being woman, perspective taking and open communication with the father were protective factors. School-leaving was a differential aspect. We insisted on the need of intervention on these variables.

Fate of Methane Emitted from Dissociating Marine Hydrates: Modeling, Laboratory, and Field Constraints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Juanes, Ruben

The overall goals of this research are: (1) to determine the physical fate of single and multiple methane bubbles emitted to the water column by dissociating gas hydrates at seep sites deep within the hydrate stability zone or at the updip limit of gas hydrate stability, and (2) to quantitatively link theoretical and laboratory findings on methane transport to the analysis of real-world field-scale methane plume data placed within the context of the degrading methane hydrate province on the US Atlantic margin. The project is arranged to advance on three interrelated fronts (numerical modeling, laboratory experiments, and analysis of field-basedmore » plume data) simultaneously. The fundamental objectives of each component are the following: Numerical modeling: Constraining the conditions under which rising bubbles become armored with hydrate, the impact of hydrate armoring on the eventual fate of a bubble’s methane, and the role of multiple bubble interactions in survival of methane plumes to very shallow depths in the water column. Laboratory experiments: Exploring the parameter space (e.g., bubble size, gas saturation in the liquid phase, “proximity” to the stability boundary) for formation of a hydrate shell around a free bubble in water, the rise rate of such bubbles, and the bubble’s acoustic characteristics using field-scale frequencies. Field component: Extending the results of numerical modeling and laboratory experiments to the field-scale using brand new, existing, public-domain, state-of-the-art real world data on US Atlantic margin methane seeps, without acquiring new field data in the course of this particular project. This component quantitatively analyzes data on Atlantic margin methane plumes and place those new plumes and their corresponding seeps within the context of gas hydrate degradation processes on this margin.« less

A Unified Kinetics and Equilibrium Experiment: Rate Law, Activation Energy, and Equilibrium Constant for the Dissociation of Ferroin

ERIC Educational Resources Information Center

Sattar, Simeen

2011-01-01

Tris(1,10-phenanthroline)iron(II) is the basis of a suite of four experiments spanning 5 weeks. Students determine the rate law, activation energy, and equilibrium constant for the dissociation of the complex ion in acid solution and base dissociation constant for phenanthroline. The focus on one chemical system simplifies a daunting set of…

Ethane-xenon mixtures under shock conditions

NASA Astrophysics Data System (ADS)

Flicker, Dawn; Magyar, Rudolph; Root, Seth; Cochrane, Kyle; Mattsson, Thomas

2015-06-01

Mixtures of light and heavy elements arise in inertial confinement fusion and planetary science. We present results on the physics of molecular scale mixing through a validation study of equation of state (EOS) properties. Density functional theory molecular dynamics (DFT/QMD) at elevated-temperature and pressure is used to obtain the properties of pure xenon, ethane, and various compressed mixture compositions along their principal Hugoniots. To validate the QMD simulations, we performed high-precision shock compression experiments using Sandia's Z-Machine. A bond tracking analysis of the simulations correlates the sharp rise in the Hugoniot curve with completion of dissociation in ethane. DFT-based simulation results compare well with experimental data and are used to provide insight into the dissociation as a function of mixture composition. Interestingly, we find that the compression ratio for complete dissociation is similar for ethane, Xe-ethane, polymethyl-pentene, and polystyrene, suggesting that a limiting compression exists for C-C bonded systems. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, Security Administration under contract DE-AC04-94AL85000.

Dissociation and serenity induction.

PubMed

Zoellner, Lori A; Sacks, Matthew B; Foa, Edna B

2007-09-01

Dissociation is a common experience during or immediately after a traumatic event; yet, most of the current knowledge regarding dissociation is retrospective in nature. The aim of the present study investigated a non-pharmacological method of dissociative induction with a clinical sample. Participants with PTSD and non-trauma exposed participants were randomly assigned to receive either a dissociative induction, or a serenity induction, based on modified Velten mood induction procedures. Participants receiving the dissociative induction reported higher state-dissociation than those receiving the serenity induction. The PTSD group reported greater state dissociation than the non-trauma exposed group, regardless of induction. State dissociation was related to trait dissociation, PTSD severity, and depression. The present results provide an initial demonstration of the viability for inducing state dissociation in the laboratory with a PTSD sample.

Schizophrenia and dissociation: Its relation with severity, self-esteem and awareness of illness.

PubMed

Justo, Ania; Risso, Alicia; Moskowitz, Andrew; Gonzalez, Anabel

2018-03-07

This article describes the conclusions of an investigation done with 120 Spanish patients: the finding of a new psychopathological profile within a subgroup of patients suffering from schizophrenia. The patients were evaluated through different questionnaires about sociodemographic data, traumatic events, the severity index (both clinical and psychopathological), self-esteem and consciousness of the illness. From the scores obtained on a scale of dissociative experiences, they were classified into two groups: high dissociative symptomatology or HD, and low dissociative symptomatology or LD. The HD group contained 44 patients (36.7% of the total population). The groups LD and HD show meaningful differences with respect to dissociative symptomatology levels, general psychopathology and level of traumatic events suffered. The percentage of patients with low self-esteem was higher in group HD than in group LD (M=25.52 front 28.76 of group LD; t (118)=2.94, p=.00). In addition, the group HD was more conscious of having a mental disorder, of the beneficial effects of medication and of the social consequences of their illness: F (1)=10.929, p=.001; ƞ2pt=0.083; 1-β=0.907. The results show the existence of a subgroup of schizophrenic patients with higher levels of dissociation and trauma that were related with higher levels of symptomatology, lower self-esteem and higher consciousness of the illness, building a population of higher severity in which it would make sense to implement coadjutant treatments specifically oriented to these variables and, in addition, opening a therapeutic possibility for the patients with refractory schizophrenia. Copyright © 2018 Elsevier B.V. All rights reserved.

Differential effects of delay upon visually and haptically guided grasping and perceptual judgments.

PubMed

Pettypiece, Charles E; Culham, Jody C; Goodale, Melvyn A

2009-05-01

Experiments with visual illusions have revealed a dissociation between the systems that mediate object perception and those responsible for object-directed action. More recently, an experiment on a haptic version of the visual size-contrast illusion has provided evidence for the notion that the haptic modality shows a similar dissociation when grasping and estimating the size of objects in real-time. Here we present evidence suggesting that the similarities between the two modalities begin to break down once a delay is introduced between when people feel the target object and when they perform the grasp or estimation. In particular, when grasping after a delay in a haptic paradigm, people scale their grasps differently when the target is presented with a flanking object of a different size (although the difference does not reflect a size-contrast effect). When estimating after a delay, however, it appears that people ignore the size of the flanking objects entirely. This does not fit well with the results commonly found in visual experiments. Thus, introducing a delay reveals important differences in the way in which haptic and visual memories are stored and accessed.

Evaluation of childhood trauma with respect to criminal behavior, dissociative experiences, adverse family experiences and psychiatric backgrounds among prison inmates.

PubMed

Altintas, Merih; Bilici, Mustafa

2018-04-01

To evaluate childhood trauma in relation to criminal behavior, dissociative experiences, adverse family experiences during childhood and psychiatric backgrounds among prison inmates. In total, 200 prison inmates were included in this questionnaire-based study. Data on demographic characteristics, adverse family experiences during childhood and psychiatric backgrounds were collected via face-to-face interviews, and a psychometric evaluation was conducted using the Childhood Trauma Questionnaire (CTQ-28) and Dissociative Experiences Scale (DES). Several historical items were more common in females than in males including family history of psychiatric disease (23.0% vs. 13.0%, p = 0.048), a personal history of psychiatric disease (51.0% vs. 29.0%, p < 0.001), and previous suicide attempts (49.0% vs. 25.0%, p < 0.001). In male inmates, in contrast, there were higher rates of substance abuse (48.0% vs. 29.0%, p < 0.001) and previous convictions (50.0% vs. 25.0%, p < 0.001). Males had a younger age at first crime (24.9 ± 8.9 years vs. 30.3 ± 9.2 years, p < 0.001), whereas females had higher rates of violent crimes (69.2% vs. 30.8% p < 0.001) and higher CTQ total scores (51.9 ± 20.9 vs. 46.2 ± 18.9, p = 0.04). A significant relationship of CTQ total score was noted with age at first offense (β = 0.772, p < 0.001) but not with sentence length (β = 0.075, p = 0.292). There were also possible mediating roles of psychiatric problems, adverse family experiences and DES in the relationship between CTQ and age at first offense. In conclusion, our findings revealed a high prevalence of and significant associations among childhood trauma, dissociative experiences, adverse family experiences and psychiatric problems in a cohort of incarcerated females and males. A psychiatric background, childhood trauma characterized by sexual abuse and violent crimes were found to be predominant in female prison inmates, whereas a criminal background with a younger age at first offense and frequent previous convictions, substance use and sexual crimes were more prevalent among male prison inmates. Our findings indicate a potential link between childhood traumatization and criminal behavior in terms of subsequent offending but not in terms of severity of the subsequent offense. Copyright © 2018. Published by Elsevier Inc.

Neural Dissociation of Number from Letter Recognition and Its Relationship to Parietal Numerical Processing

ERIC Educational Resources Information Center

Park, Joonkoo; Hebrank, Andrew; Polk, Thad A.; Park, Denise C.

2012-01-01

The visual recognition of letters dissociates from the recognition of numbers at both the behavioral and neural level. In this article, using fMRI, we investigate whether the visual recognition of numbers dissociates from letters, thereby establishing a double dissociation. In Experiment 1, participants viewed strings of consonants and Arabic…

Parameterized cross sections for Coulomb dissociation in heavy-ion collisions

NASA Technical Reports Server (NTRS)

Norbury, John W.; Cucinotta, F. A.; Townsend, L. W.; Badavi, F. F.

1988-01-01

Simple parameterizations of Coulomb dissociation cross sections for use in heavy-ion transport calculations are presented and compared to available experimental dissociation data. The agreement between calculation and experiment is satisfactory considering the simplicity of the calculations.

Formation, aggregation and reactivity of amorphous ferric oxyhydroxides on dissociation of Fe(III)-organic complexes in dilute aqueous suspensions

NASA Astrophysics Data System (ADS)

Bligh, Mark W.; Waite, T. David

2010-10-01

While chemical reactions that take place at the surface of amorphous ferric oxides (AFO) are known to be important in aquatic systems, incorporation of these reactions into kinetic models is hindered by a lack of ability to reliably quantify the reactivity of the surface and the changes in reactivity that occur over time. Long term decreases in the reactivity of iron oxides may be considered to result from changes in the molecular structure of the solid, however, over shorter time scales where substantial aggregation may occur, the mechanisms of reactivity loss are less clear. Precipitation of AFO may be described as a combination of homogeneous and heterogeneous reactions, however, despite its potentially significant role, the latter reaction is usually neglected in kinetic models of aquatic processes. Here, we investigate the role of AFO in scavenging dissolved inorganic ferric (Fe(III)) species (Fe') via the heterogeneous precipitation reaction during the net dissociation of organically complexed Fe(III) in seawater. Using sulfosalicylic acid (SSA) as a model ligand, AFO was shown to play a significant role in inducing the net dissociation of the Fe-SSA complexes with equations describing both the heterogeneous precipitation reaction and the aging of AFO being required to adequately describe the experimental data. An aggregation based mechanism provided a good description of AFO aging over the short time scale of the experiments. The behaviour of AFO described here has implications for the bioavailability of iron in natural systems as a result of reactions involving AFO which are recognised to occur over time scales of minutes, including adsorption of Fe' and AFO dissolution, precipitation and ageing.

Absorption spectrum of the firefly luciferin anion isolated in vacuo.

PubMed

Støchkel, Kristian; Milne, Bruce F; Brøndsted Nielsen, Steen

2011-03-24

The excited-state physics of the firefly luciferin anion depends on its chemical environment, and it is therefore important to establish the intrinsic behavior of the bare ion. Here we report electronic absorption spectra of the anion isolated in vacuo obtained at an electrostatic ion storage ring and an accelerator mass spectrometer where ionic dissociation is monitored on a long time scale (from 33 μs and up to 3 ms) and on a short time scale (0-3 μs), respectively. In the ring experiment the yield of all neutrals (mainly CO(2)) as a function of wavelength was measured whereas in the single pass experiment, the abundance of daughter ions formed after loss of CO(2) was recorded to provide action spectra. We find maxima at 535 and 265 nm, and that the band shape is largely determined by the sampling time interval, which is due to the kinetics of the dissociation process. Calculations at the TD-B3LYP/TZVPP++ level predict maximum absorption at 533 and 275 nm for the carboxylate isomer in excellent agreement with the experimental findings. The phenolate isomer lies higher in energy by 0.22 eV, and also its absorption maximum is calculated to be at 463 nm, which is far away from the experimental value. Our data serve to benchmark future theoretical models for bioluminescence from fireflies.

Pain, dissociation and subliminal self-representations.

PubMed

Bob, Petr

2008-03-01

According to recent evidence, neurophysiological processes coupled to pain are closely related to the mechanisms of consciousness. This evidence is in accordance with findings that changes in states of consciousness during hypnosis or traumatic dissociation strongly affect conscious perception and experience of pain, and markedly influence brain functions. Past research indicates that painful experience may induce dissociated state and information about the experience may be stored or processed unconsciously. Reported findings suggest common neurophysiological mechanisms of pain and dissociation and point to a hypothesis of dissociation as a defense mechanism against psychological and physical pain that substantially influences functions of consciousness. The hypothesis is also supported by findings that information can be represented in the mind/brain without the subject's awareness. The findings of unconsciously present information suggest possible binding between conscious contents and self-functions that constitute self-representational dimensions of consciousness. The self-representation means that certain inner states of own body are interpreted as mental and somatic identity, while other bodily signals, currently not accessible to the dominant interpreter's access are dissociated and may be defined as subliminal self-representations. In conclusion, the neurophysiological aspects of consciousness and its integrative role in the therapy of painful traumatic memories are discussed.

The role of attachment in recovery after a school-shooting trauma

PubMed Central

Turunen, Tuija; Haravuori, Henna; Punamäki, Raija-Leena; Suomalainen, Laura; Marttunen, Mauri

2014-01-01

Background Survivors of life-endangering trauma use varying resources that help them to recover. Attachment system activates in the times of distress, and is expected to associate with stress responses, arousal regulation, and mental health. Objective We examined the associations of attachment style with posttraumatic stress disorders (PTSD) symptoms and dissociative symptoms, and posttraumatic growth (PTG) among students exposed to a school shooting in Finland in a three-wave follow-up setting. Method Participants were students (Mage=24.9 years; 95% female) who were followed 4 (T1, N=236), 16 (T2, N=180), and 28 months (T3, N=137) after the shooting. The assessments included the Attachment Style Questionnaire, the Impact of Event Scale, part of the Adolescent Dissociative Experiences Scale and the Posttraumatic Growth Inventory. Results Securely attached survivors had lower levels of posttraumatic stress and dissociative symptoms than preoccupied at T1 and T2 as hypothesized. At T3 survivors with avoidant attachment style had higher levels of intrusive and hyperarousal symptoms than those with secure style. Concerning PTG, survivors with avoidant attachment style scored lower in PTG at T3 than survivors with both secure and preoccupied style. Conclusion Secure attachment style was beneficial in trauma recovery. A challenge to the health care systems is to acknowledge that survivors with preoccupied and avoidant attachment styles react uniquely to trauma, and thus need help in different doses, modalities, and timings. PMID:25018861

The Dimensionality of Reasoning: Inductive and Deductive Inference can be Explained by a Single Process.

PubMed

Hayes, Brett K; Stephens, Rachel G; Ngo, Jeremy; Dunn, John C

2018-02-01

Three-experiments examined the number of qualitatively different processing dimensions needed to account for inductive and deductive reasoning. In each study, participants were presented with arguments that varied in logical validity and consistency with background knowledge (believability), and evaluated them according to deductive criteria (whether the conclusion was necessarily true given the premises) or inductive criteria (whether the conclusion was plausible given the premises). We examined factors including working memory load (Experiments 1 and 2), individual working memory capacity (Experiments 1 and 2), and decision time (Experiment 3), which according to dual-processing theories, modulate the contribution of heuristic and analytic processes to reasoning. A number of empirical dissociations were found. Argument validity affected deduction more than induction. Argument believability affected induction more than deduction. Lower working memory capacity reduced sensitivity to argument validity and increased sensitivity to argument believability, especially under induction instructions. Reduced decision time led to decreased sensitivity to argument validity. State-trace analyses of each experiment, however, found that only a single underlying dimension was required to explain patterns of inductive and deductive judgments. These results show that the dissociations, which have traditionally been seen as supporting dual-processing models of reasoning, are consistent with a single-process model that assumes a common evidentiary scale for induction and deduction. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Regional Center of Excellence for PTSD: Phoebe Putney Memorial Hospital

DTIC Science & Technology

2011-09-01

Acting or feeling as if the traumatic event were recurring (includes a sense of reliving the experience, illusions, hallucinations, and dissociative ...illusions, hallucinations, and dissociative flashback episodes, including those that occur on awakening or when intoxicated). Note: In young children...definite but transient dissociative quality, still very aware of surroundings, daydreaming quality 3 Severe, strongly dissociative (reports images

Imaging a multidimensional multichannel potential energy surface: Photodetachment of H(-)(NH3) and NH4 (.).

PubMed

Hu, Qichi; Song, Hongwei; Johnson, Christopher J; Li, Jun; Guo, Hua; Continetti, Robert E

2016-06-28

Probes of the Born-Oppenheimer potential energy surfaces governing polyatomic molecules often rely on spectroscopy for the bound regions or collision experiments in the continuum. A combined spectroscopic and half-collision approach to image nuclear dynamics in a multidimensional and multichannel system is reported here. The Rydberg radical NH4 and the double Rydberg anion NH4 (-) represent a polyatomic system for benchmarking electronic structure and nine-dimensional quantum dynamics calculations. Photodetachment of the H(-)(NH3) ion-dipole complex and the NH4 (-) DRA probes different regions on the neutral NH4 PES. Photoelectron energy and angular distributions at photon energies of 1.17, 1.60, and 2.33 eV compare well with quantum dynamics. Photoelectron-photofragment coincidence experiments indicate dissociation of the nascent NH4 Rydberg radical occurs to H + NH3 with a peak kinetic energy of 0.13 eV, showing the ground state of NH4 to be unstable, decaying by tunneling-induced dissociation on a time scale beyond the present scope of multidimensional quantum dynamics.

Racial discrimination as race-based trauma, coping strategies, and dissociative symptoms among emerging adults.

PubMed

Polanco-Roman, Lillian; Danies, Ashley; Anglin, Deidre M

2016-09-01

The race-based traumatic stress theory (Carter, 2007) suggests that some racial- and ethnic-minority individuals experience racial discrimination as psychological trauma, as it may elicit a response comparable to posttraumatic stress. In the present study, we examined this further by determining the relation between racial discrimination and dissociation, a common response to trauma exposure. Further, we examined whether active coping strategies specifically employed to cope with racial discrimination related to less dissociative symptomatology. The predominant racial- and ethnic-minority sample (N = 743) of emerging adults, ages 18-29, recruited from a public university in northeastern United States completed a battery of self-report measures on racial discrimination, responses to racial discrimination, traumatic life events, and dissociative symptoms. Frequency of racial discrimination was positively associated with dissociative symptoms in regression analyses adjusted for demographics and other traumatic life events. In addition, more active coping strategies in response to racial discrimination were negatively associated with dissociative symptoms. Racial- and ethnic-minority emerging adults who experience racial discrimination, possibly as traumatic, may be more vulnerable to dissociative symptoms. However, different strategies of coping with racial discrimination may differentially impact risk for dissociation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Racial discrimination as race-based trauma, coping strategies and dissociative symptoms among emerging adults

PubMed Central

Polanco-Roman, Lillian; Danies, Ashley; Anglin, Deidre M.

2016-01-01

Objective The race-based traumatic stress theory (Carter, 2007) suggests that some racial and ethnic minority individuals may experience racial discrimination as a psychological trauma, as it may elicit a response comparable to posttraumatic stress. The present study examined this further by determining the relation between racial discrimination and dissociation, a common response to trauma exposure. Further, we examined whether active coping strategies specifically employed to cope with racial discrimination related to less dissociative symptomatology. Methods The predominant racial and ethnic minority sample (N=743) of emerging adults (i.e., ages 18-29) recruited from a public university in Northeastern U.S. completed a battery of self-report measures on racial discrimination, responses to racial discrimination, traumatic life events and dissociative symptoms. Results Frequency of racial discrimination was positively associated with dissociative symptoms in regression analyses adjusted for demographics and other traumatic life events. Additionally, more active coping strategies in response to racial discrimination were negatively associated with dissociative symptoms. Conclusion Racial and ethnic minority emerging adults who experience racial discrimination, possibly as traumatic, may be more vulnerable to dissociative symptoms. However, different strategies of coping with racial discrimination may differentially impact risk for dissociation. PMID:26963957

Individual correlates of self-stigma in patients with anxiety disorders with and without comorbidities

PubMed Central

Ociskova, Marie; Prasko, Jan; Kamaradova, Dana; Grambal, Ales; Sigmundova, Zuzana

2015-01-01

Background A number of psychiatric patients experience stigma connected to prejudices about mental disorders. It has been shown that stigma is most harmful when it is internalized. Most of the studies were performed on individuals either with psychoses or with mood disorders, and hence, there are almost no studies with other diagnostic categories. The goals of this research were to identify factors that are significantly related to self-stigma in patients with anxiety disorders and to suggest possible models of causality for these relationships. Methods A total of 109 patients with anxiety disorders and possible comorbid depressive or personality disorders, who were admitted to the psychotherapeutic department participated in this study. All patients completed several psychodiagnostic methods, ie, the Internalized Stigma of Mental Illness Scale, Temperament and Character Inventory-Revised Version, Adult Dispositional Hope Scale, Dissociative Experiences Scale, Beck Anxiety Inventory, Beck Depression Inventory-Second Edition, and Clinical Global Impression (also completed by the senior psychiatrist). Results The overall level of self-stigma was positively associated with a comorbid personality disorder, more severe symptomatology, more intense symptoms of anxiety and depression, and higher levels of dissociation and harm avoidance. Self-stigma was negatively related to hope, reward dependence, persistence, self-directedness, and cooperativeness. Multiple regression analysis showed that the most significant factors connected to self-stigma are harm avoidance, the intensity of depressive symptoms, and self-directedness. Two models of causality were proposed and validated. It seems that the tendency to dissociate in stress increases the probability of development of self-stigma, and this relationship is entirely mediated by avoidance of harm. Conversely, self-directedness lowers the probability of occurrence of self-stigma, and this effect is partly mediated by hope. Conclusion Patients with anxiety disorders accompanied with or without comorbid depressive or personality disorders may suffer from self-stigma. Individuals with greater sensitivity to rejection and other socially aversive stimuli are prone to the development of self-stigma. Other personality factors, such as hopeful thinking and self-acceptance serve as factors promoting resilience concerning self-stigma. PMID:26229471

CH4 dissociation on Ru(0001): A view from both sides of the barrier

NASA Astrophysics Data System (ADS)

Mortensen, H.; Diekhöner, L.; Baurichter, A.; Luntz, A. C.

2002-04-01

This paper reports measurements of both dissociative adsorption on and associative desorption from CH4 on Ru(0001). We consider the former a view of dissociation from the front side of the barrier, while the latter is considered as a view of dissociation from the back side of the barrier. A combination of both previous and new molecular beam measurements of dissociative adsorption shows that S0 depends on all experimental variables (E, Tn, Ts and isotope) in a manner similar to other close-packed transition metals. The interpretation of this behavior in terms of a theoretical description of the dissociation is discussed critically, with special emphasis on insights from new theoretical studies. The energy-resolved desorption flux Df(E,Ts) is obtained in associative desorption experiments using the technique of laser assisted associative desorption (LAAD). Measurements at several Ts allow both a direct determination of the adiabatic barrier V*(0) and considerable insight into the dynamics of dissociation. The V*(0) obtained from Df(E,Ts) is in excellent agreement with density functional theory (DFT) calculations and with the value indirectly inferred from molecular beam experiments. The chief dynamic conclusion from an analysis of Df(E,Ts) is that both bending and stretching coordinates must be produced in associative desorption, although they are not populated statistically. The absence of an isotope effect in the shape of Df(E,Ts) argues against the importance of tunneling in the desorption/adsorption. When reactive fluxes are compared via detailed balance, both the molecular beam experiment and the LAAD experiment are in good agreement.

Latent profile analysis and principal axis factoring of the DSM-5 dissociative subtype.

PubMed

Frewen, Paul A; Brown, Matthew F D; Steuwe, Carolin; Lanius, Ruth A

2015-01-01

A dissociative subtype has been recognized based on the presence of experiences of depersonalization and derealization in relation to DSM-IV posttraumatic stress disorder (PTSD). However, the dissociative subtype has not been assessed in a community sample in relation to the revised DSM-5 PTSD criteria. Moreover, the 20-item PTSD Checklist for DSM-5 (PCL-5) currently does not assess depersonalization and derealization. We therefore evaluated two items for assessing depersonalization and derealization in 557 participants recruited online who endorsed PTSD symptoms of at least moderate severity on the PCL-5. A five-class solution identified two PTSD classes who endorsed dissociative experiences associated with either 1) severe or 2) moderate PTSD symptom severity (D-PTSD classes). Those in the severe dissociative class were particularly likely to endorse histories of childhood physical and sexual abuse. A principal axis factor analysis of the symptom list identified six latent variables: 1) Reexperiencing, 2) Emotional Numbing/Anhedonia, 3) Dissociation, 4) Negative Alterations in Cognition & Mood, 5) Avoidance, and 6) Hyperarousal. The present results further support the presence of a dissociative subtype within the DSM-5 criteria for PTSD.

Description and control of dissociation channels in gas-phase protein complexes

NASA Astrophysics Data System (ADS)

Thachuk, Mark; Fegan, Sarah K.; Raheem, Nigare

2016-08-01

Using molecular dynamics simulations of a coarse-grained model of the charged apo-hemoglobin protein complex, this work expands upon our initial report [S. K. Fegan and M. Thachuk, J. Am. Soc. Mass Spectrom. 25, 722-728 (2014)] about control of dissociation channels in the gas phase using specially designed charge tags. Employing a charge hopping algorithm and a range of temperatures, a variety of dissociation channels are found for activated gas-phase protein complexes. At low temperatures, a single monomer unfolds and becomes charge enriched. At higher temperatures, two additional channels open: (i) two monomers unfold and charge enrich and (ii) two monomers compete for unfolding with one eventually dominating and the other reattaching to the complex. At even higher temperatures, other more complex dissociation channels open with three or more monomers competing for unfolding. A model charge tag with five sites is specially designed to either attract or exclude charges. By attaching this tag to the N-terminus of specific monomers, the unfolding of those monomers can be decidedly enhanced or suppressed. In other words, using charge tags to direct the motion of charges in a protein complex provides a mechanism for controlling dissociation. This technique could be used in mass spectrometry experiments to direct forces at specific attachment points in a protein complex, and hence increase the diversity of product channels available for quantitative analysis. In turn, this could provide insight into the function of the protein complex in its native biological environment. From a dynamics perspective, this system provides an interesting example of cooperative behaviour involving motions with differing time scales.

Trait Dissociation and the Subjective Affective, Motivational, and Phenomenological Experience of Self-Defining Memories

PubMed Central

Sutin, Angelina R.; Stockdale, Gary D.

2010-01-01

The present research reports two studies that examine the relation between non-pathological trait dissociation and the subjective affect, motivation, and phenomenology of self-defining memories. In Study 1 (N=293), participants retrieved and rated the emotional and motivational experience of a general and a positive and negative achievement-related memory. Study 2 (N=449) extended these ratings to relationship-related memories and the phenomenological experience of the memory. Dissociation was associated with incongruent affect in valenced memories (e.g., positive affect in a negative memory) and memories that were visually incoherent and saturated with power motivation, hubristic pride, and shame, regardless of valence or domain. The present findings demonstrate that autobiographical memories, which integrate emotional, motivational, and phenomenological components, reflect the emotional and motivational processes inherent to dissociation. PMID:21204840

A general mechanism for competitor-induced dissociation of molecular complexes

PubMed Central

Paramanathan, Thayaparan; Reeves, Daniel; Friedman, Larry J.; Kondev, Jane; Gelles, Jeff

2014-01-01

The kinetic stability of non-covalent macromolecular complexes controls many biological phenomena. Here we find that physical models of complex dissociation predict that competitor molecules will in general accelerate the breakdown of isolated bimolecular complexes by occluding rapid rebinding of the two binding partners. This prediction is largely independent of molecular details. We confirm the prediction with single-molecule fluorescence experiments on a well-characterized DNA strand dissociation reaction. Contrary to common assumptions, competitor–induced acceleration of dissociation can occur in biologically relevant competitor concentration ranges and does not necessarily implyternary association of competitor with the bimolecular complex. Thus, occlusion of complex rebinding may play a significant role in a variety of biomolecular processes. The results also show that single-molecule colocalization experiments can accurately measure dissociation rates despite their limited spatio temporal resolution. PMID:25342513

Dissociative States and Neural Complexity

ERIC Educational Resources Information Center

Bob, Petr; Svetlak, Miroslav

2011-01-01

Recent findings indicate that neural mechanisms of consciousness are related to integration of distributed neural assemblies. This neural integration is particularly vulnerable to past stressful experiences that can lead to disintegration and dissociation of consciousness. These findings suggest that dissociation could be described as a level of…

Controls on methane expulsion during melting of natural gas hydrate systems. Topic area 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flemings, Peter

1.1. Project Goal The project goal is to predict, given characteristic climate-induced temperature change scenarios, the conditions under which gas will be expelled from existing accumulations of gas hydrate into the shallow ocean or directly to the atmosphere. When those conditions are met, the fraction of the gas accumulation that escapes and the rate of escape shall be quantified. The predictions shall be applicable in Arctic regions and in gas hydrate systems at the up dip limit of the stability zone on continental margins. The behavior shall be explored in response to two warming scenarios: longer term change due tomore » sea level rise (e.g. 20 thousand years) and shorter term due to atmospheric warming by anthropogenic forcing (decadal time scale). 1.2. Project Objectives During the first budget period, the objectives are to review and categorize the stability state of existing well-studied hydrate reservoirs, develop conceptual and numerical models of the melting process, and to design and conduct laboratory experiments that dissociate methane hydrate in a model sediment column by systematically controlling the temperature profile along the column. The final objective of the first budget period shall be to validate the models against the experiments. In the second budget period, the objectives are to develop a model of gas flow into sediment in which hydrate is thermodynamically stable, and conduct laboratory experiments of this process to validate the model. The developed models shall be used to quantify the rate and volume of gas that escapes from dissociating hydrate accumulations. In addition, specific scaled simulations characteristic of Arctic regions and regions near the stability limit at continental margins shall be performed. 1.3. Project Background and Rationale The central hypothesis proposed is that hydrate melting (dissociation) due to climate change generates free gas that can, under certain conditions, propagate through the gas hydrate stability zone and vent at the seafloor. Gas venting through the regional hydrate stability zone is accomplished by alteration of the regional equilibrium conditions (creation of three phase conditions) by increased salinity and heat due to hydrate formation, due to gas fracturing, or a combination of both. This research will explore the controls on whether methane reaches the seafloor (or atmosphere) as the original hydrate deposit dissociates and what the magnitude of these fluxes are. This hypothesis has significant implications for the forcings and feedbacks associated with climate change. It is described below the observations and models that have led to formulating this hypothesis.« less

MDMA, cannabis, and cocaine produce acute dissociative symptoms.

PubMed

van Heugten-Van der Kloet, Dalena; Giesbrecht, Timo; van Wel, Janelle; Bosker, Wendy M; Kuypers, Kim P C; Theunissen, Eef L; Spronk, Desirée B; Jan Verkes, Robbert; Merckelbach, Harald; Ramaekers, Johannes G

2015-08-30

Some drugs of abuse may produce dissociative symptoms, but this aspect has been understudied. We explored the dissociative potential of three recreational drugs (3,4-methylenedioxymethamphetamine (MDMA), cannabis, and cocaine) during intoxication and compared their effects to literature reports of dissociative states in various samples. Two placebo-controlled studies were conducted. In Study 1 (N=16), participants received single doses of 25, 50, and 100 mg of MDMA, and placebo. In Study 2 (N=21), cannabis (THC 300 µg/kg), cocaine (HCl 300 mg), and placebo were administered. Dissociative symptoms as measured with the Clinician-Administered Dissociative States Scale (CADSS) significantly increased under the influence of MDMA and cannabis. To a lesser extent, this was also true for cocaine. Dissociative symptoms following MDMA and cannabis largely exceeded those observed in schizophrenia patients, were comparable with those observed in Special Forces soldiers undergoing survival training, but were lower compared with ketamine-induced dissociation. Cocaine produced dissociative symptoms that were comparable with those observed in schizophrenia patients, but markedly less than those in Special Forces soldiers and ketamine users. Thus, MDMA and cannabis can produce dissociative symptoms that resemble dissociative pathology. The study of drug induced dissociation is important, because it may shed light on the mechanisms involved in dissociative psychopathology. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Global functioning and disability in dissociative disorders.

PubMed

Mueller-Pfeiffer, Christoph; Rufibach, Kaspar; Perron, Noelle; Wyss, Daniela; Kuenzler, Cornelia; Prezewowsky, Cornelia; Pitman, Roger K; Rufer, Michael

2012-12-30

Dissociative disorders are frequent comorbid conditions of other mental disorders. Yet, there is controversy about their clinical relevance, and little systematic research has been done on how they influence global functioning. Outpatients and day care patients (N=160) of several psychiatric units in Switzerland were assessed with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV Axis I Disorders, Structured Clinical Interview for DSM-IV Dissociative Disorders, Global Assessment of Functioning Scale, and World Health Organization Disability Assessment Schedule-II. The association between subjects with a dissociative disorder (N=30) and functional impairment after accounting for non-dissociative axis I disorders was evaluated by linear regression models. We found a proportion of 18.8% dissociative disorders (dissociative amnesia=0%, dissociative fugue=0.6%, depersonalization disorder=4.4%, dissociative identity disorder=7.5%, dissociative disorder-not-otherwise-specified=6.3%) across treatment settings. Adjusted for other axis I disorders, subjects with a comorbid dissociative identity disorder or dissociative disorder-not-otherwise-specified had a median global assessment of functioning score that was 0.86 and 0.88 times, respectively, the score of subjects without a comorbid dissociative disorder. These findings support the hypothesis that complex dissociative disorders, i.e., dissociative identity disorder and dissociative disorder-not-otherwise-specified, contribute to functional impairment above and beyond the impact of co-existing non-dissociative axis I disorders, and that they qualify as "serious mental illness". Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Psychological Dissection of Patients Having Dissociative Disorder: A Cross-sectional Study

PubMed Central

Reddy, Lohit Somashekar; Patil, N. M.; Nayak, Raghavendra B.; Chate, Sameeran S.; Ansari, Saba

2018-01-01

Background: Patients present with dissociative disorders as a decompensation to underlying stressful situation. It is clinically important to evaluate the presence, type, and temporal relation of the stressors resulting in dissociation. Further knowing the sociodemographic and psychological profile of the dissociative patient helps in better management. Materials and Methods: The study included 55 dissociative patients aged between 5 to 45 years. Psychiatric diagnosis was made using ICD-10 DCR. Psychosocial stressors and stressful life events were assessed using presumptive stressful life events scale/life events scale for Indian children and clinical interview. Personality and temperament traits were assessed using medico psychological questionnaire and temperament measurement schedule, respectively. Intelligence quotient (IQ) was assessed using standard progressive matrices and colored progressive matrices. Statistical analysis was done using Epi Info 7 software. Results: All patients had significant psychosocial stressors preceding dissociation. Precipitating factor with temporal association was observed in only 83.64%. Family disharmony (41.82%) followed by education-related problems (29.09%) was the most common psychosocial stressors. 61.82% of the dissociative patients had psychiatric comorbidity. Mean IQ of study sample was 92.47. Dissociative children had high emotionality and energy levels but low sociability, rhythmicity, and distractibility. 50% of the adults were neurotic and had emotionally unstable personality. Conclusion: Dissociative disorders are commonly seen in females, adolescents, and in those from lower socioeconomic status and rural areas. They are always preceded by psychosocial stressors. Most of them have comorbid psychiatric disorders such as depression and anxiety. Neuroticism and emotionally unstable personality traits are common in adult patients while temperamental traits such as low sociability, low rhythmicity, low distractibility, high emotionality, and high energy levels are common in children. PMID:29403129

Psychological Dissection of Patients Having Dissociative Disorder: A Cross-sectional Study.

PubMed

Reddy, Lohit Somashekar; Patil, N M; Nayak, Raghavendra B; Chate, Sameeran S; Ansari, Saba

2018-01-01

Patients present with dissociative disorders as a decompensation to underlying stressful situation. It is clinically important to evaluate the presence, type, and temporal relation of the stressors resulting in dissociation. Further knowing the sociodemographic and psychological profile of the dissociative patient helps in better management. The study included 55 dissociative patients aged between 5 to 45 years. Psychiatric diagnosis was made using ICD-10 DCR. Psychosocial stressors and stressful life events were assessed using presumptive stressful life events scale/life events scale for Indian children and clinical interview. Personality and temperament traits were assessed using medico psychological questionnaire and temperament measurement schedule, respectively. Intelligence quotient (IQ) was assessed using standard progressive matrices and colored progressive matrices. Statistical analysis was done using Epi Info 7 software. All patients had significant psychosocial stressors preceding dissociation. Precipitating factor with temporal association was observed in only 83.64%. Family disharmony (41.82%) followed by education-related problems (29.09%) was the most common psychosocial stressors. 61.82% of the dissociative patients had psychiatric comorbidity. Mean IQ of study sample was 92.47. Dissociative children had high emotionality and energy levels but low sociability, rhythmicity, and distractibility. 50% of the adults were neurotic and had emotionally unstable personality. Dissociative disorders are commonly seen in females, adolescents, and in those from lower socioeconomic status and rural areas. They are always preceded by psychosocial stressors. Most of them have comorbid psychiatric disorders such as depression and anxiety. Neuroticism and emotionally unstable personality traits are common in adult patients while temperamental traits such as low sociability, low rhythmicity, low distractibility, high emotionality, and high energy levels are common in children.

Startle modulation and explicit valence evaluations dissociate during backward fear conditioning.

PubMed

Luck, Camilla C; Lipp, Ottmar V

2017-05-01

Blink startle magnitude is linearly modulated by affect such that, relative to neutral stimuli, startle magnitude is inhibited during pleasant stimuli and potentiated during unpleasant stimuli. Andreatta, Mühlberger, Yarali, Gerber, and Pauli (2010), however, report a dissociation between startle modulation and explicit valence evaluations during backward conditioning, a procedure in which the unconditional stimulus precedes the conditional stimulus (CS). Relative to controls, startles elicited during the CS were inhibited, suggesting that the CS had acquired positive valence, but participants still evaluated the CS as unpleasant after the experiment. In Experiment 1, we aimed to replicate this dissociation using a trial-by-trial measure of CS valence to measure startle modulation and CS valence simultaneously during forward and backward differential fear conditioning. In Experiment 2, we examined whether early and late portions of the CS could acquire differential valence by presenting startle probes at early and late probe positions during the CS. In both experiments, the dissociation between startle modulation and explicit valence evaluations in backward conditioning replicated, with CS+ evaluated as less pleasant than CS-, but startles elicited during CS+ inhibited relative to CS-. In Experiment 2, we provide preliminary evidence that this inhibition was present early, but not late, during the CS+. The results replicate the dissociation between implicit and explicit CS valence reported by Andreatta et al. (2010) using a trial-by-trial measure of valence. We also provide preliminary evidence that this dissociation may occur because the implicit and explicit measures are recorded at different times during the CS presentation. © 2017 Society for Psychophysiological Research.

Unusual Sleep Experiences, Dissociation, and Schizotypy: Evidence for a Common Domain

PubMed Central

Koffel, Erin; Watson, David

2009-01-01

This paper reviews studies that have examined associations between unusual sleep experiences (including nightmares, vivid dreaming, narcolepsy symptoms, and complex nighttime behaviors) and dissociation and schizotypy. Using correlational studies and structural analyses, evidence is provided that unusual sleep experiences, dissociation, and schizotypy belong to a common domain. It is demonstrated that unusual sleep experiences show specificity to dissociation and schizotypy compared to other daytime symptoms (e.g., anxiety, depression, substance use) and other sleep disturbances (e.g., insomnia, lassitude/fatigue). The paper also outlines the methodological limitations of the existing evidence and makes suggestions for future research. Finally, three models for the overlap of daytime and nighttime symptoms are reviewed, including biological abnormalities, trauma, and personality traits. Although further research is needed, it is suggested that daytime and nighttime symptoms result from problems with sleep-wake state boundaries, which may be precipitated by stress or trauma. In addition, association between daytime and nighttime symptoms can be attributed to the higher order personality trait of Oddity. PMID:19581031

Silicone Tubes - Simple and Effective Tools for Gas Extraction and Monitoring in the Course of Hydrate Dissociation

NASA Astrophysics Data System (ADS)

Strauch, B.; Schicks, J. M.; Zimmer, M.

2015-12-01

The in situ dissociation of gas hydrate is prerequisite for the commercial recovery of natural gas from hydrate deposits. We examined different methods such as depressurization, thermal stimulation and distortion of the chemical equilibrium by carbon dioxide sequestration for methane gas production from hydrates within our Large Scale reservoir simulator LARS in a pilot plant scale. Within this setup, thin-walled (0.8 mm) silicon tubes are utilized for in situ gas capture. They function as membranes for the extraction of methane gas, leaving sediment and brine behind. The gas capture via silicone tube membranes is, due to their robust nature, reliably applicable in remote and rough areas. First tests show that, driven by the transmembrane pressure difference, the methane flux through these membranes is about 1 mL per minute per cm² membrane surface at a reservoir pressure of about 20 MPa. This is in good agreement with values reported in the literature [e.g. 2]. The operation of the membranes as a simple capture tool for the released methane from a hydrate deposit is therefore considered as feasible. Furthermore, silicone tube membranes are suitable for the quantification of free and dissolved gas volumes. For the monitoring of spatial and temporal gas distribution, LARS has been equipped with several silicone membranes at various locations. They have been utilized to monitor the progress of hydrate formation and decomposition and show that inhomogeneous gas distributions within the reservoir are detectable and terminable. The quantification of carbon dioxide/methane gas ratios during exchange experiments, however, is due to differences in water solubility and permeation rates of the gas species challenging. The study assesses the capability and limits of silicone tubes as membranes for gas extraction and as a tool to monitor gas distribution and composition in the course of hydrate dissociation experiments. [1] Merkel, T.C.; Bodnar, V.I.; Nagai, K.; Freeman, B.D.; Pinnau, I. J. Polym. Sci. Part B Polym. Phys. 2000, 38, 415-434.

Abstractive dissociation of oxygen over Al(111): a nonadiabatic quantum model.

PubMed

Katz, Gil; Kosloff, Ronnie; Zeiri, Yehuda

2004-02-22

The dissociation of oxygen on a clean aluminum surface is studied theoretically. A nonadiabatic quantum dynamical model is used, based on four electronically distinct potential energy surfaces characterized by the extent of charge transfer from the metal to the adsorbate. A flat surface approximation is used to reduce the computation complexity. The conservation of the helicopter angular momentum allows Boltzmann averaging of the outcome of the propagation of a three degrees of freedom wave function. The dissociation event is simulated by solving the time-dependent Schrödinger equation for a period of 30 femtoseconds. As a function of incident kinetic energy, the dissociation yield follows the experimental trend. An attempt at simulation employing only the lowest adiabatic surface failed, qualitatively disagreeing with both experiment and nonadiabatic calculations. The final products, adsorptive dissociation and abstractive dissociation, are obtained by carrying out a semiclassical molecular dynamics simulation with surface hopping which describes the back charge transfer from an oxygen atom negative ion to the surface. The final adsorbed oxygen pair distribution compares well with experiment. By running the dynamical events backward in time, a correlation is established between the products and the initial conditions which lead to their production. Qualitative agreement is thus obtained with recent experiments that show suppression of abstraction by rotational excitation. (c) 2004 American Institute of Physics.

Traumatic Experience and Somatoform Dissociation Among Spirit Possession Practitioners in the Dominican Republic.

PubMed

Schaffler, Yvonne; Cardeña, Etzel; Reijman, Sophie; Haluza, Daniela

2016-03-01

Recent studies in African contexts have revealed a strong association between spirit possession and severe trauma, with inclusion into a possession cult serving at times a therapeutic function. Research on spirit possession in the Dominican Republic has so far not included quantitative studies of trauma and dissociation. This study evaluated demographic variables, somatoform dissociative symptoms, and potentially traumatizing events in the Dominican Republic with a group of Vodou practitioners that either do or do not experience spirit possession. Inter-group comparisons revealed that in contrast to non-possessed participants (n = 38), those experiencing spirit possession (n = 47) reported greater somatoform dissociation, more problems with sleep, and previous exposure to mortal danger such as assaults, accidents, or diseases. The two groups did not differ significantly in other types of trauma. The best predictor variable for group classification was somatoform dissociation, although those items could also reflect the experience of followers during a possession episode. A factor analysis across variables resulted in three factors: having to take responsibility early on in life and taking on a professional spiritual role; traumatic events and pain; and distress/dissociation. In comparison with the non-possessed individuals, the possessed ones did not seem to overall have a remarkably more severe story of trauma and seemed to derive economic gains from possession practice.

Electromagnetic dissociation of U-238 in heavy-ion collisions at 120 MeV/A

NASA Astrophysics Data System (ADS)

Justice, M. L.

1991-04-01

This thesis describes a measurement of the heavy-ion induced electromagnetic dissociation of a 120 MeV/A U-238 beam incident on five targets: Be-9, Al-27, Cu, Ag, and U. Electromagnetic dissociation at this beam energy is essentially a two step process involving the excitation of a giant resonance followed by particle decay. At 120 MeV/A there is predicted to be a significant contribution of the giant quadrupole resonance to the EMD cross sections. The specific exit channel which was looked at was projectile fission. The two fission fragments were detected in coincidence by an array of solid-state (Delta)E-E detectors, allowing the changes of the fragments to be determined to within (+/-) .5 units. The events were sorted on the basis of the sums of the fragments' charges, acceptance corrections were applied, and total cross sections for the most peripheral events were determined. Electromagnetic fission at the beam energy of this experiment always leads to a true charge sum of 92. Due to the imperfect resolution of the detectors, charge sums of 91 and 93 were included in order to account for all of the electromagnetic fission events. The experimentally observed cross sections are due to nuclear interaction processes as well as electromagnetic processes. Under the conditions of this experiment, the cross sections for the beryllium target are almost entirely due to nuclear processes. The nuclear cross sections for the other four targets were determined by extrapolation from the beryllium data using a geometrical scaling model. After subtraction of the nuclear cross sections, the resulting electromagnetic cross sections are compared to theoretical calculations based on the equivalent photon approximation. Systematic uncertainties are discussed and suggestions for improving the experiment are given.

A Genetic Analysis of Individual Differences in Dissociative Behaviors in Childhood and Adolescence

ERIC Educational Resources Information Center

Becker-Blease, Kathryn A.; Deater-Deckard, Kirby; Eley, Thalia; Freyd, Jennifer J.; Stevenson, Jim; Plomin, Robert

2004-01-01

Background: Dissociation--a pattern of general disruption in memory and consciousness--has been found to be an important cognitive component of children's and adults' coping with severe trauma. Dissociative experiences include amnesia, identity disturbance, age regression, difficulty with concentration, and trance states. Stable individual…

Psychological factors and treatment effectiveness in resistant anxiety disorders in highly comorbid inpatients

PubMed Central

Ociskova, Marie; Prasko, Jan; Latalova, Klara; Kamaradova, Dana; Grambal, Ales

2016-01-01

Background Anxiety disorders are a group of various mental syndromes that have been related with generally poor treatment response. Several psychological factors may improve or hinder treatment effectiveness. Hope has a direct impact on the effectiveness of psychotherapy. Also, dissociation is a significant factor influencing treatment efficiency in this group of disorders. Development of self-stigma could decrease treatment effectiveness, as well as several temperamental and character traits. The aim of this study was to explore a relationship between selected psychological factors and treatment efficacy in anxiety disorders. Subjects and methods A total of 109 inpatients suffering from anxiety disorders with high frequency of comorbidity with depression and/or personality disorder were evaluated at the start of the treatment by the following scales: the Mini-International Neuropsychiatric Interview, the Internalized Stigma of Mental Illness scale, the Adult Dispositional Hope Scale, and the Temperament and Character Inventory – revised. The participants, who sought treatment for anxiety disorders, completed the following scales at the beginning and end of an inpatient-therapy program: Clinical Global Impression (objective and subjective) the Beck Depression Inventory – second edition, the Beck Anxiety Inventory, and the Dissociative Experiences Scale. The treatment consisted of 25 group sessions and five individual sessions of cognitive behavioral therapy or psychodynamic therapy in combination with pharmacotherapy. There was no randomization to the type of group-therapy program. Results Greater improvement in psychopathology, assessed by relative change in objective Clinical Global Impression score, was connected with low initial dissociation level, harm avoidance, and self-stigma, and higher amounts of hope and self-directedness. Also, individuals without a comorbid personality disorder improved considerably more than comorbid patients. According to backward-stepwise multiple regression, the best significant predictor of treatment effectiveness was the initial level of self-stigma. Conclusion The initial higher levels of self-stigma predict a lower effectiveness of treatment in resistant-anxiety-disorder patients with high comorbidity with depression and/or personality disorder. The results suggest that an increased focus on self-stigma during therapy could lead to better treatment outcomes. PMID:27445474

Trauma-induced dissociative amnesia in World War I combat soldiers.

PubMed

van der Hart, O; Brown, P; Graafland, M

1999-02-01

This study relates trauma-induced dissociative amnesia reported in World War I (WW I) studies of war trauma to contemporary findings of dissociative amnesia in victims of childhood sexual abuse. Key diagnostic studies of post-traumatic amnesia in WW I combatants are surveyed. These cover phenomenology and the psychological dynamics of dissociation vis-à-vis repression. Descriptive evidence is cited for war trauma-induced dissociative amnesia. Posttraumatic amnesia extends beyond the experience of sexual and combat trauma and is a protean symptom, which reflects responses to the gamut of traumatic events.

Latent profile analysis and principal axis factoring of the DSM-5 dissociative subtype

PubMed Central

Frewen, Paul A.; Brown, Matthew F. D.; Steuwe, Carolin; Lanius, Ruth A.

2015-01-01

Objective A dissociative subtype has been recognized based on the presence of experiences of depersonalization and derealization in relation to DSM-IV posttraumatic stress disorder (PTSD). However, the dissociative subtype has not been assessed in a community sample in relation to the revised DSM-5 PTSD criteria. Moreover, the 20-item PTSD Checklist for DSM-5 (PCL-5) currently does not assess depersonalization and derealization. Method We therefore evaluated two items for assessing depersonalization and derealization in 557 participants recruited online who endorsed PTSD symptoms of at least moderate severity on the PCL-5. Results A five-class solution identified two PTSD classes who endorsed dissociative experiences associated with either 1) severe or 2) moderate PTSD symptom severity (D-PTSD classes). Those in the severe dissociative class were particularly likely to endorse histories of childhood physical and sexual abuse. A principal axis factor analysis of the symptom list identified six latent variables: 1) Reexperiencing, 2) Emotional Numbing/Anhedonia, 3) Dissociation, 4) Negative Alterations in Cognition & Mood, 5) Avoidance, and 6) Hyperarousal. Conclusions The present results further support the presence of a dissociative subtype within the DSM-5 criteria for PTSD. PMID:25854673

Dissociated learning using GABAergic drugs.

PubMed

Azarashvili, A A; Kaimachnikova, I E

2009-02-01

Experiments on Wistar rats addressed the possibility of dissociated learning using drugs acting directly on brain GABA(B) receptors. A previously suggested hypothesis was tested: that the cholinergic system of the brain plays the decisive role in the mechanisms of dissociative learning. The data obtained here provided evidence that dissociated learning an occur with compounds acting on the GABAergic transmitter system of the brain. Dissociated states arose on treatment of animals with both the GABA-mimetic baclofen and the GABA receptor antagonist 5-aminovaleric acid. Thus, these results show that dissociated learning can occur using drugs acting on both the cholinergic and the GABAergic transmitter systems of the brain.

Owning the past, claiming the present: perspectives on the treatment of dissociative patients.

PubMed

Middleton, Warwick

2005-03-01

From the early 1990s there has been a growing awareness in Australia of dissociative processes and dissociative disorders. The objective in this paper is to provide a selective overview of the context and process of treatment based on the substantive dissociative disorders literature, ongoing clinical experience and research, and over 8 years as director of a trauma and dissociation unit at Belmont Hospital, Brisbane. The construct of individual selfhood is of direct relevance in illustrating the psychological damage sustained by patients who have relied on dissociative defences to survive, and in highlighting issues and areas that are a particular focus of informed treatment.

Distinct contributions of the fornix and inferior longitudinal fasciculus to episodic and semantic autobiographical memory.

PubMed

Hodgetts, Carl J; Postans, Mark; Warne, Naomi; Varnava, Alice; Lawrence, Andrew D; Graham, Kim S

2017-09-01

Autobiographical memory (AM) is multifaceted, incorporating the vivid retrieval of contextual detail (episodic AM), together with semantic knowledge that infuses meaning and coherence into past events (semantic AM). While neuropsychological evidence highlights a role for the hippocampus and anterior temporal lobe (ATL) in episodic and semantic AM, respectively, it is unclear whether these constitute dissociable large-scale AM networks. We used high angular resolution diffusion-weighted imaging and constrained spherical deconvolution-based tractography to assess white matter microstructure in 27 healthy young adult participants who were asked to recall past experiences using word cues. Inter-individual variation in the microstructure of the fornix (the main hippocampal input/output pathway) related to the amount of episodic, but not semantic, detail in AMs - independent of memory age. Conversely, microstructure of the inferior longitudinal fasciculus, linking occipitotemporal regions with ATL, correlated with semantic, but not episodic, AMs. Further, these significant correlations remained when controlling for hippocampal and ATL grey matter volume, respectively. This striking correlational double dissociation supports the view that distinct, large-scale distributed brain circuits underpin context and concepts in AM. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Awareness is relative: dissociation as the organisation of meaning.

PubMed

Lesley, Joan

2006-09-01

This essay discusses how the organisation of mental material within the cognitive system can influence consciousness and awareness, and presents a theory of dissociation based on the premise that awareness is relative, contingent on the activated representation of the ongoing event being linked to the activated self-representation. It allows four possible variations of integration: (i) non-integrated experience--perceptions about an object/event are either not perceived or they remain at the sensory level: traditional dissociative states, amnesia, depersonalisation etc; (ii) variably integrated experience--activation of information of a specific valence about an object blocks activation of information of contrasting valence: splitting; (iii) alternatively integrated experience--experience is integrated into a specific, limited active self-representation: fugue and multiple identity states; (iv) dis-integrated experience-the ongoing experience of innate drives and needs is no longer consistently activated in the core self-representation: repression and isolation.

Spontaneous and Deliberate Dissociative States in Military Personnel: Relationships to Objective Performance Under Stress

DTIC Science & Technology

2014-09-01

their military work. The course consists of didactic and experiential phases. The didactic phase is classroom based; during this phase students learn the...U.S. Code of Conduct and basic survival skills. The experiential phase requires students to demonstrate field sur- vival skills and resistance to...Clinician-Administered Dissociative States Scale (CADSS)18 were used to assess the frequency and intensity of state symptoms of dissociation with

Terror and bliss? Commonalities and distinctions between sleep paralysis, lucid dreaming, and their associations with waking life experiences.

PubMed

Denis, Dan; Poerio, Giulia L

2017-02-01

Sleep paralysis and lucid dreaming are both dissociated experiences related to rapid eye movement (REM) sleep. Anecdotal evidence suggests that episodes of sleep paralysis and lucid dreaming are related but different experiences. In this study we test this claim systematically for the first time in an online survey with 1928 participants (age range: 18-82 years; 53% female). Confirming anecdotal evidence, sleep paralysis and lucid dreaming frequency were related positively and this association was most apparent between lucid dreaming and sleep paralysis episodes featuring vestibular-motor hallucinations. Dissociative experiences were the only common (positive) predictor of both sleep paralysis and lucid dreaming. Both experiences showed different associations with other key variables of interest: sleep paralysis was predicted by sleep quality, anxiety and life stress, whereas lucid dreaming was predicted by a positive constructive daydreaming style and vividness of sensory imagery. Overall, results suggest that dissociative experiences during wakefulness are reflected in dissociative experiences during REM sleep; while sleep paralysis is related primarily to issues of sleep quality and wellbeing, lucid dreaming may reflect a continuation of greater imaginative capacity and positive imagery in waking states. © 2016 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.

Acute stress symptoms, dissociation, and depression among rescue personnel 24 hours after the Bet-Yehoshua train crash in Israel:the effect of gender.

PubMed

Palgi, Yuval; Ben-Ezra, Menachem; Essar, Nir; Sofer, Hilik; Haber, Yeela

2009-01-01

The effect of immediate exposure to traumatic events and gender differences is under-studied in the literature. Most studies focus on acute stress disorder (ASD) and post-traumatic stress disorder (PTSD) phases in order to measure gender differences, and tend to neglect the immediate exposure to the disaster. The main hypothesis was that female rescue personnel would exhibit higher levels of acute stress symptoms, dissociation, and depressive symptoms in the 24 hours following a traumatic event. Twenty-three rescue personnel participated in a search and rescue operation at the Bet-Yehoshua train crash in Israel. The rescue personnel group was divided based on gender. Each participant completed a demographic questionnaire including questions that assessed psychological symptoms and issues such as perceived threat to life, the Impact of Event Scale Revised (IES-R), the Dissociative Experience Scale (DES), and the Center of Epidemiologic Studies Depression questionnaire (CES-D). Statistical inferences were calculated using t-tests and chi-square tests, along with testing of covariance (MANCOVA) in order to indentify which factors are related to psychiatric symptomatology following the immediate exposure to disaster. The results suggest that among rescue personnel, women did not differ in their levels of acute stress, dissociation, and depressive symptoms from men. These results suggest the possibility that the gender differences in reactions to traumatic events do not emerge in the acute stress reactions (ASR) phase (up to 24 hours after the event), but later on when people have time to process the trauma. Another possibility that may explain the discrepancy between this study and the common knowledge in the literature is that women rescue personnel are considered a highly selected group, which does not reflect on the general population of women. More studies are needed in order to substantiate these results.

CO2 Dissociation using the Versatile Atmospheric Dielectric Barrier Discharge Experiment (VADER)

NASA Astrophysics Data System (ADS)

Lindon, Michael Allen

As of 2013, the Carbon Dioxide Information Analysis Center (CDIAC) estimates that the world emits approximately 36 trillion metric tons of Carbon Dioxide (CO2) into the atmosphere every year. These large emissions have been correlated to global warming trends that have many consequences across the globe, including glacial retraction, ocean acidification and increased severity of weather events. With green technologies still in the infancy stage, it can be expected that CO2 emissions will stay this way for along time to come. Approximately 41% of the emissions are due to electricity production, which pump out condensed forms of CO2. This danger to our world is why research towards new and innovative ways of controlling CO2 emissions from these large sources is necessary. As of now, research is focused on two primary methods of CO2 reduction from condensed CO2 emission sources (like fossil fuel power plants): Carbon Capture and Sequestration (CCS) and Carbon Capture and Utilization (CCU). CCS is the process of collecting CO2 using absorbers or chemicals, extracting the gas from those absorbers and finally pumping the gas into reservoirs. CCU on the other hand, is the process of reacting CO2 to form value added chemicals, which can then be recycled or stored chemically. A Dielectric Barrier discharge (DBD) is a pulsed, low temperature, non-thermal, atmospheric pressure plasma which creates high energy electrons suitable for dissociating CO2 into its components (CO and O) as one step in the CCU process. Here I discuss the viability of using a DBD for CO2 dissociation on an industrial scale as well as the fundamental physics and chemistry of a DBD for CO2 dissociation. This work involved modeling the DBD discharge and chemistry, which showed that there are specific chemical pathways and plasma parameters that can be adjusted to improve the CO2 reaction efficiencies and rates. Experimental studies using the Versatile Atmospheric dielectric barrier Discharge ExpeRiment (VADER) demonstrated how different factors, like voltage, frequency and the addition of a photocatalyst, change the efficiency of CO2 dissociation in VADER and the plasma chemistry involved.

Process dissociation between contextual retrieval and item recognition.

PubMed

Weis, Susanne; Specht, Karsten; Klaver, Peter; Tendolkar, Indira; Willmes, Klaus; Ruhlmann, Jürgen; Elger, Christian E; Fernández, Guillén

2004-12-22

We employed a source memory task in an event related fMRI study to dissociate MTL processes associated with either contextual retrieval or item recognition. To introduce context during study, stimuli (photographs of buildings and natural landscapes) were transformed into one of four single-color-scales: red, blue, yellow, or green. In the subsequent old/new recognition memory test, all stimuli were presented as gray scale photographs, and old-responses were followed by a four-alternative source judgment referring to the color in which the stimulus was presented during study. Our results suggest a clear-cut process dissociation within the human MTL. While an activity increase accompanies successful retrieval of contextual information, an activity decrease provides a familiarity signal that is sufficient for successful item recognition.

Hugoniot equation of state of Si-doped glow discharge polymer and scaling to other plastic ablators

NASA Astrophysics Data System (ADS)

Huser, G.; Ozaki, N.; Colin-Lalu, P.; Recoules, V.; Sano, T.; Sakawa, Y.; Miyanishi, K.; Kodama, R.

2018-05-01

Pressure, density, and temperature were measured along the principal Hugoniot of the Si-doped Glow Discharge Polymer used in Inertial Confinement Fusion (ICF) capsules up to 5 Mbar, covering conditions beyond the first shock in a full-scale Inertial Confinement Fusion (ICF) capsule. The experiments were performed using the GEKKOXII laser at the Institute of Laser Engineering at Osaka University in Japan. Results are in good agreement with predictions obtained from ab initio Hugoniot calculations, but softer than the quotidian equation of state average atom model. Ab initio calculations show that dissociation of carbon bonds need to be taken into account in order to explain Hugoniot compressibility.

Effects of fracture and crack healing in sI methane and sII methane-ethane gas hydrate

NASA Astrophysics Data System (ADS)

Helgerud, M. B.; Waite, W. F.; Stern, L. A.; Kirby, S. H.

2005-12-01

Cracking within gas hydrate-bearing sediment can occur in the field at core-scales, due to unloading as material is brought to the surface during conventional coring, and at reservoir scales if the formation is fractured prior to production. Cracking can weaken hydrate-bearing sediment, but can also provide additional surface area for dissociation and permeability pathways for enhanced gas and fluid flow. In pulse-transmission wave speed measurements, we observe cracking in laboratory-formed pure sI methane and sII methane-ethane hydrates when samples are axially unloaded while being held under gas pressure to maintain hydrate stability. Cracking events are inferred from repeated, sharp decreases in shear wave speed occurring concurrently with abrupt increases in sample length. We also visually observe cracks in the solid samples after their recovery from the apparatus following each experiment. Following a cracking event, we observe evidence of rapid crack healing, or annealing expressed as nearly complete recovery of the shear wave speed within approximately 20 minutes. Gas hydrate recrystallization, grain growth, and annealing have also been observed in optical cell experiments and SEM imagery over a similar time frame. In a recovered hydrate-bearing core that is repressurized for storage or experimentation, rapid crack healing and recrystallization can partly restore lost mechanical strength and raise wave speeds. In a fractured portion of a hydrate-bearing reservoir, the rapid healing process can close permeable cracks and reduce the surface area available for dissociation.

Depersonalization and derealization in self-report and clinical interview: The spectrum of borderline personality disorder, dissociative disorders, and healthy controls.

PubMed

Sar, Vedat; Alioğlu, Firdevs; Akyuz, Gamze

2017-01-01

Depersonalization (DEP) and derealization (DER) were examined among college students with and without borderline personality disorder (BPD) and/or dissociative disorders (DDs) by self-report and clinician assessment. The Steinberg Depersonalization Questionnaire (SDEPQ), the Steinberg Derealization Questionnaire (SDERQ), the Childhood Trauma Questionnaire, and the screening tool of the BPD section of the Structured Clinical Interview for DSM-IV (SCID-BPD) were administered to 1,301 students. Those with BPD (n = 80) according to the SCID-BPD and 111 non-BPD controls were evaluated using the Structured Clinical Interview for DSM-IV Dissociative Disorders by a psychiatrist blind to the diagnosis. Of the participants, 19.7% reported SDEPQ (17.8%) and/or SDERQ (11.0%) scores above cutoff levels and impairment from these experiences. Principal component analysis of 26 items of both scales yielded 4 factors: cognitive-emotional self-detachment, perceptual detachment, bodily self-detachment, and detachment from reality. Participants with concurrent DD and BPD had the highest scores for DEP and DER in the clinical interview and self-report. The total number of BPD criteria was associated with the severity of childhood trauma and dissociation. Both BPD and DD were associated with clinician-assessed and self-reported DER, self-reported DEP, and the cognitive-emotional self-detachment factor. Unlike BPD, DD was associated with clinician-assessed DEP, and BPD was related to the self-reported detachment from reality factor. Although the latter was correlated with the total childhood trauma score, possibly because of dissociative amnesia, clinician-assessed DER was not. Being the closest factor to BPD, the factor of detachment from reality warrants further study.

Dissociative symptoms and dissociative disorder comorbidity in patients with obsessive-compulsive disorder.

PubMed

Belli, Hasan; Ural, Cenk; Vardar, Melek Kanarya; Yesılyurt, Sema; Oncu, Fatıh

2012-10-01

The present study attempted to assess the dissociative symptoms and overall dissociative disorder comorbidity in patients with obsessive-compulsive disorder (OCD). In addition, we examined the relationship between the severity of obsessive-compulsive symptoms and dissociative symptoms. All patients admitted for the first time to the psychiatric outpatient unit were included in the study. Seventy-eight patients had been diagnosed as having OCD during the 2-year study period. Patients had to meet the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for OCD. Most (76.9%; n = 60) of the patients were female, and 23.1% (n = 18) of the patients were male. Dissociation Questionnaire was used to measure dissociative symptoms. The Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Dissociative Disorders interviews and Yale-Brown Obsessive Compulsive Checklist and Severity Scale were used. Eleven (14%) of the patients with OCD had comorbid dissociative disorder. The most prevalent disorder in our study was dissociative depersonalization disorder. Dissociative amnesia and dissociative identity disorder were common as well. The mean Yale-Brown score was 23.37 ± 7.27 points. Dissociation Questionnaire scores were between 0.40 and 3.87 points, and the mean was 2.23 ± 0.76 points. There was a statistically significant positive correlation between Yale-Brown points and Dissociation Questionnaire points. We conclude that dissociative symptoms among patients with OCD should alert clinicians for the presence of a chronic and complex dissociative disorder. Clinicians may overlook an underlying dissociative process in patients who have severe symptoms of OCD. However, a lack of adequate response to cognitive-behavioral and drug therapy may be a consequence of dissociative process. Copyright © 2012 Elsevier Inc. All rights reserved.

[Differential diagnosis between dissociative disorders and schizophrenia].

PubMed

Shibayama, Masatoshi

2011-01-01

The differential diagnosis of dissociative disorders includes many psychiatric disorders, such as schizophrenia, bipolar disorders (especially bipolar II disorder), depressive disorder (especially atypical depression), epilepsy, Asperger syndrome, and borderline personality disorder. The theme of this paper is the differential diagnosis between dissociative disorders and schizophrenia. Schneiderian first-rank symptoms in schizophrenia are common in dissociative disorders, especially in dissociative identity disorder (DID). Many DID patients have been misdiagnosed as schizophrenics and treated with neuroleptics. We compared and examined Schneiderian symptoms of schizophrenia and those of dissociative disorders from a structural viewpoint. In dissociative disorders, delusional perception and somatic passivity are not seen. "Lateness" and "Precedence of the Other" originated from the concept of "Pattern Reversal" (H. Yasunaga)" is characteristic of schizophrenia. It is important to check these basic structure of schizophrenia in subjective experiences in differential diagnosis between dissociative disorders and schizophrenia.

[Verification of the double dissociation model of shyness using the implicit association test].

PubMed

Fujii, Tsutomu; Aikawa, Atsushi

2013-12-01

The "double dissociation model" of shyness proposed by Asendorpf, Banse, and Mtücke (2002) was demonstrated in Japan by Aikawa and Fujii (2011). However, the generalizability of the double dissociation model of shyness was uncertain. The present study examined whether the results reported in Aikawa and Fujii (2011) would be replicated. In Study 1, college students (n = 91) completed explicit self-ratings of shyness and other personality scales. In Study 2, forty-eight participants completed IAT (Implicit Association Test) for shyness, and their friends (n = 141) rated those participants on various personality scales. The results revealed that only the explicit self-concept ratings predicted other-rated low praise-seeking behavior, sociable behavior and high rejection-avoidance behavior (controlled shy behavior). Only the implicit self-concept measured by the shyness IAT predicted other-rated high interpersonal tension (spontaneous shy behavior). The results of this study are similar to the findings of the previous research, which supports generalizability of the double dissociation model of shyness.

Electron-Transfer/Higher-Energy Collision Dissociation (EThcD)-Enabled Intact Glycopeptide/Glycoproteome Characterization

NASA Astrophysics Data System (ADS)

Yu, Qing; Wang, Bowen; Chen, Zhengwei; Urabe, Go; Glover, Matthew S.; Shi, Xudong; Guo, Lian-Wang; Kent, K. Craig; Li, Lingjun

2017-09-01

Protein glycosylation, one of the most heterogeneous post-translational modifications, can play a major role in cellular signal transduction and disease progression. Traditional mass spectrometry (MS)-based large-scale glycoprotein sequencing studies heavily rely on identifying enzymatically released glycans and their original peptide backbone separately, as there is no efficient fragmentation method to produce unbiased glycan and peptide product ions simultaneously in a single spectrum, and that can be conveniently applied to high throughput glycoproteome characterization, especially for N-glycopeptides, which can have much more branched glycan side chains than relatively less complex O-linked glycans. In this study, a redefined electron-transfer/higher-energy collision dissociation (EThcD) fragmentation scheme is applied to incorporate both glycan and peptide fragments in one single spectrum, enabling complete information to be gathered and great microheterogeneity details to be revealed. Fetuin was first utilized to prove the applicability with 19 glycopeptides and corresponding five glycosylation sites identified. Subsequent experiments tested its utility for human plasma N-glycoproteins. Large-scale studies explored N-glycoproteomics in rat carotid arteries over the course of restenosis progression to investigate the potential role of glycosylation. The integrated fragmentation scheme provides a powerful tool for the analysis of intact N-glycopeptides and N-glycoproteomics. We also anticipate this approach can be readily applied to large-scale O-glycoproteome characterization. [Figure not available: see fulltext.

Schizophrenia-like symptoms in narcolepsy type 1: shared and distinctive clinical characteristics.

PubMed

Plazzi, Giuseppe; Fabbri, Chiara; Pizza, Fabio; Serretti, Alessandro

2015-01-01

The occurrence of psychotic symptoms in narcolepsy type 1 (NT1) has been reported as responsible for delayed diagnosis due to the misdiagnosis of schizophrenia. This study aimed to identify shared and distinctive clinical characteristics between NT1 and schizophrenia, with the focus on psychotic symptoms. A total of 28 NT1 and 21 schizophrenia patients were included. Hallucination characteristics and PANSS (Positive and Negative Syndrome Scale), HRSD (Hamilton Rating Scale for Depression), DES (Dissociative Experiences Scale), and STAI (State-Trait Anxiety Inventory) scores were collected. Symptom overlap was investigated by χ(2), Fisher's or t tests and multiple logistic regression models. Hallucinations and illusions frequently occurred in both diseases. Unimodal hallucinations were more common in schizophrenia (p = 6.30e-07) and multimodal hallucinations in NT1, but no clear difference was identified in their sensory modality. Hypnagogic/hypnopompic hallucinations were typical of NT1 (p = 5.22e-07), and 25% of NT1 patients exhibited some degree of insight deficit. Hypnagogic/hypnopompic hallucinations, unimodal hallucinations and PANSS score were the most distinctive clinical characteristics. Clinical overlap was found in the dissociative and anxiety domains, while higher depressive scores were observed in schizophrenia. The overlap between NT1 and schizophrenia should be further investigated under a clinical and pathogenetic point of view to improve diagnostic and therapeutic approaches. © 2015 S. Karger AG, Basel.

Bond Strength and Reactivity Scales for Lewis Superacid Adducts: A Comparative Study with In(OTf)3 and Al(OTf)3.

PubMed

Compain, Guillaume; Sikk, Lauri; Massi, Lionel; Gal, Jean-François; Duñach, Elisabet

2017-03-17

Metal triflates, often called Lewis superacids, are potent catalysts for organic synthesis. However, the reactivity of a given Lewis superacid toward a given base is difficult to anticipate. A systematic screening of catalysts is often necessary when developing synthetic methodologies. Presented herein is the development of quantitative reactivity and bond strength scales by using mass spectrometry (MS). By applying a collision-induced dissociation (CID) technique to the adducts formed between Lewis superacids Al(OTf) 3 or In(OTf) 3 with a series of amides bases, including monodentate and bidentate ligands, different dissociation pathways were observed. Quantitative relative energy scales were established by performing energy-resolved mass spectrometry (ERMS) analysis on the adducts. ERMS of the adducts affords a bond strength scale when the fragmentation leads to the loss of a ligand, and reactivity scales when the dissociation leads to the C-F bond activation of one triflate anion or the deprotonation of the ligand. Al(OTf) 3 was found to bind stronger to amides than In(OTf) 3 and to provide the most reactive adducts. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

“I can’t tell whether it’s my hand”: a pilot study of the neurophenomenology of body representation during the rubber hand illusion in trauma-related disorders

PubMed Central

Rabellino, Daniela; Harricharan, Sherain; Frewen, Paul A.; Burin, Dalila; McKinnon, Margaret C.; Lanius, Ruth A.

2016-01-01

Background Early traumatic experiences are thought to be causal factors in the development of trauma-related dissociative experiences, including depersonalization and derealization. The rubber hand illusion (RHI), a well-known paradigm that measures multi-sensorial integration of a rubber hand into one’s own body representation, has been used to investigate alterations in the experience of body ownership and of body representation. Critically, however, it has never been studied in individuals with trauma-related disorders. Objective To investigate body representation distortions occurring in trauma-related disorders in response to the RHI. Method The RHI was administered to three individuals with the dissociative subtype of posttraumatic stress disorder (PTSD), and subjective, behavioral, cardiovascular and skin conductance responses were recorded. Results Participants’ subjective experiences of the RHI were differentiated and complex. The illusion was induced following both synchronous and asynchronous brushing and variably evoked subjective distress, depersonalization and derealization experiences, tonic immobility, increased physiological arousal and flashbacks. Conclusions The present findings point towards the RHI as a strong provocation stimulus that elicits individual patterns of symptom presentation, including experiences of distress and dissociation, in individuals with trauma-related disorders, including the dissociative subtype of PTSD. Highlights of the article The rubber hand illusion (RHI) elicits distress, tonic immobility, depersonalization and derealization, and autonomic responses in individuals with trauma-related disorders, including the dissociative subtype of posttraumatic stress disorder (PTSD). RHI effects related to body misrepresentation may trigger altered experiences related to body ownership. The RHI represents a promising paradigm for studying the neurophenomenology of body distortion in individuals experiencing trauma-related altered states of consciousness (TRASC). PMID:27876453

Does dissociation offer a useful explanation for psychopathology?

PubMed

Jureidini, Jon

2004-01-01

Dissociation is often conceptualised as an altered state of consciousness, a trance-like state in which normal barriers between conscious and unconscious memories, desires and beliefs break down and other amnestic barriers emerge. This review explores whether it is likely that there is a neurophysiology of pathological dissociative processes that will elucidate management. A critical reading of current research, sourced through Medline and Psychinfo searches from 1990 to 2002, using subject headings: dissociative disorders, hypnosis and stress disorder (post-traumatic), as well as keywords: dissociation, hypnosis and trance. Current knowledge does not support the notion of dissociation as a discrete brain state or process. Psychiatric and neurophysiological research and theory development are better directed towards individual components that contribute to dissociative experience. Copyright (c) 2004 S. Karger AG, Basel.

Dissociating Stimulus-Set and Response-Set in the Context of Task-Set Switching

PubMed Central

Kieffaber, Paul D.; Kruschke, John K.; Cho, Raymond Y.; Walker, Philip M.; Hetrick, William P.

2014-01-01

The primary aim of the present research was to determine how stimulus-set and response-set components of task-set contribute to switch costs and conflict processing. Three experiments are described wherein participants completed an explicitly cued task-switching procedure. Experiment 1 established that task switches requiring a reconfiguration of both stimulus- and response-set incurred larger residual switch costs than task switches requiring the reconfiguration of stimulus-set alone. Between-task interference was also drastically reduced for response-set conflict compared with stimulus-set conflict. A second experiment replicated these findings and demonstrated that stimulus- and response-conflict have dissociable effects on the “decision time” and “motor time” components of total response time. Finally, a third experiment replicated Experiment 2 and demonstrated that the stimulus- and response- components of task switching and conflict processing elicit dissociable neural activity as evidence by event-related brain potentials. PMID:22984990

Possession experiences in dissociative identity disorder: a preliminary study.

PubMed

Ross, Colin A

2011-01-01

Dissociative trance disorder, which includes possession experiences, was introduced as a provisional diagnosis requiring further study in the Diagnostic and Statistical Manual of Mental Disorders (4th ed.). Consideration is now being given to including possession experiences within dissociative identity disorder (DID) in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.), which is due to be published in 2013. In order to provide empirical data relevant to the relationship between DID and possession states, I analyzed data on the prevalence of trance, possession states, sleepwalking, and paranormal experiences in 3 large samples: patients with DID from North America; psychiatric outpatients from Shanghai, China; and a general population sample from Winnipeg, Canada. Trance, sleepwalking, paranormal, and possession experiences were much more common in the DID patients than in the 2 comparison samples. The study is preliminary and exploratory in nature because the samples were not matched in any way.

Effectiveness of trauma-focused treatment for patients with psychosis with and without the dissociative subtype of post-traumatic stress disorder.

PubMed

van Minnen, A; van der Vleugel, B M; van den Berg, D P G; de Bont, P A J M; de Roos, C; van der Gaag, M; de Jongh, A

2016-10-01

This study presents secondary analyses of a recently published trial in which post-traumatic stress disorder (PTSD) patients with psychosis (n = 108) underwent 8 sessions of trauma-focused treatment, either prolonged exposure (PE) or eye movement desensitisation and reprocessing (EMDR) therapy. 24.1% fulfilled the criteria for the dissociative subtype, a newly introduced PTSD subtype in DSM-5. Treatment outcome was compared for patients with and without the dissociative subtype of PTSD. Patients with the dissociative subtype of PTSD showed large reductions in clinician-administered PTSD scale (CAPS) score, comparable with patients without the dissociative subtype of PTSD. It is concluded that even in a population with severe mental illness, patients with the dissociative subtype of PTSD do benefit from trauma-focused treatments without a pre-phase of emotion regulation skill training and should not be excluded from these treatments. © The Royal College of Psychiatrists 2016.

Imaging a multidimensional multichannel potential energy surface: Photodetachment of H{sup −}(NH{sub 3}) and NH{sub 4}{sup −}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Qichi; Johnson, Christopher J.; Continetti, Robert E., E-mail: hguo@umn.edu, E-mail: rcontinetti@ucsd.edu

2016-06-28

Probes of the Born-Oppenheimer potential energy surfaces governing polyatomic molecules often rely on spectroscopy for the bound regions or collision experiments in the continuum. A combined spectroscopic and half-collision approach to image nuclear dynamics in a multidimensional and multichannel system is reported here. The Rydberg radical NH{sub 4} and the double Rydberg anion NH{sub 4}{sup −} represent a polyatomic system for benchmarking electronic structure and nine-dimensional quantum dynamics calculations. Photodetachment of the H{sup −}(NH{sub 3}) ion-dipole complex and the NH{sub 4}{sup −} DRA probes different regions on the neutral NH{sub 4} PES. Photoelectron energy and angular distributions at photon energiesmore » of 1.17, 1.60, and 2.33 eV compare well with quantum dynamics. Photoelectron-photofragment coincidence experiments indicate dissociation of the nascent NH{sub 4} Rydberg radical occurs to H + NH{sub 3} with a peak kinetic energy of 0.13 eV, showing the ground state of NH{sub 4} to be unstable, decaying by tunneling-induced dissociation on a time scale beyond the present scope of multidimensional quantum dynamics.« less

Regional Center of Excellence for PTSD: Phoebe Putney Memorial Hospital

DTIC Science & Technology

2011-09-01

hallucinations, and dissociative flashback episodes, including those that occur upon awakening or when intoxicated). Note: in children, trauma...sense of reliving the experience, illusions, hallucinations, and dissociative flashback episodes, including those that occur on awakening or when...thinking about event 2 Moderate, definite but transient dissociative quality, still very aware of surroundings, daydreaming quality 3 Severe

Relationship of Purported Measures of Pathological and Nonpathological Dissociation to Self-Reported Psychological Distress and Fantasy Immersion

ERIC Educational Resources Information Center

Levin, Ross; Spei, Ekaterina

2004-01-01

In order to investigate both the psychometric structure of the Dissociative Experiences Survey (DES) and the discriminant validity of the DES-Taxon (Waller, Putnam, & Carlson, 1996) as a specific marker of pathological dissociation, 376 non-clinical community based respondents completed the DES and a battery of psychopathology and imaginative…

Symptom overreporting and dissociative experiences: A qualitative review.

PubMed

Merckelbach, H; Boskovic, I; Pesy, D; Dalsklev, M; Lynn, S J

2017-03-01

We discuss a phenomenon that has received little attention to date in research on dissociative phenomena, namely that self-reports of these phenomena overlap with the tendency to overendorse eccentric items. We review the literature documenting the dissociation-overreporting link and then briefly discuss various interpretations of this link: (1) overreporting is an artifact of measuring dissociative symptoms; (2) dissociative psychopathology engenders overreporting of eccentric symptoms through fantasy proneness or impairments in internal monitoring; (3) an overreporting response style as is evident in malingerers, for example, promotes reports of dissociative symptoms. These three interpretations are not mutually exclusive. Also, the dissociation-overreporting link may have different origins among different samples. Because overreporting may introduce noise in datasets, we need more research specifically aimed at disentangling the dissociation-overreporting link. We suggest various avenues to accomplish this goal. Copyright © 2017 Elsevier Inc. All rights reserved.

Dispositional optimism and self-esteem as competing predictors of acute symptoms of generalized anxiety disorders and dissociative experiences among civilians exposed to war trauma.

PubMed

Weinberg, Michael; Besser, Avi; Zeigler-Hill, Virgil; Neria, Yuval

2015-01-01

Although previous studies have rarely examined predictors of acute emotional responses to war trauma, this "natural laboratory" study aimed to examine the role that individual differences in dispositional optimism and self-esteem play in the development of acute symptoms of generalized anxiety disorder (GAD) and dissociative experiences. A sample of 140 female adults exposed to missile and rocket fire during an eruption of violence in the Middle East in November 2012 was assessed during real-time exposure. The results demonstrate inverse associations between dispositional optimism and acute symptoms of GAD and dissociation. The associations were accounted for by individual differences in self-esteem. In addition, individuals with low levels of dispositional optimism demonstrated a higher risk for acute GAD and dissociative experiences, in part because of their low levels of self-esteem. Theoretical and clinical implications of the findings are discussed. (c) 2015 APA, all rights reserved).

Flow and dissociation: examination of mean levels, cross-links, and links to emotional well-being across sports and recreational and pathological gambling.

PubMed

Wanner, Brigitte; Ladouceur, Robert; Auclair, Amélie V; Vitaro, Frank

2006-01-01

To examine whether flow (Csikszentmihalyi (1990). Flow: The psychology of optimal experience. NY: Harper & Row) and dissociation (Jacobs (1986). Journal of Gambling Behavior, 2, 15-31) are experienced across sports and recreational and pathological gambling, we assessed a sample of 511 college students (256 females and 255 males, M age = 19.54) that was comprised of 14 pathological gamblers, 21 non-addicted gamblers, and 476 athletes. The findings showed that both flow and dissociation lay on a continuum of subjective experiences across activity groups. Specifically, pathological gamblers experienced lower levels of flow than athletes, whereas recreational gamblers lay in between the previous groups in this regard. In contrast, pathological gamblers experienced higher mean levels of dissociation than athletes and recreational gamblers who, in turn, were similar in this regard. A LISREL model showed that flow was positively associated with general emotional well-being, whereas dissociation was negatively associated with well-being.

Alexithymia, Dissociation, and Social Desirability: Investigating Individual Differences in the Narrative Content of False Allegations of Trauma

ERIC Educational Resources Information Center

Peace, Kristine A.; Bouvier, Kristen A.

2008-01-01

This study examined the potential influence of alexithymia, dissociation, and social desirability on the narrative features associated with truthful and fabricated traumatic events. Participants (N = 291) wrote narratives describing both genuine and fabricated traumas and completed scales measuring individual differences. Alexithymia was…

Altered responsiveness in psychogenic nonepileptic seizures and its implication to underlying psychopathology.

PubMed

Baslet, Gaston; Tolchin, Benjamin; Dworetzky, Barbara A

2017-11-01

Altered responsiveness during psychogenic nonepileptic seizures (PNES) is a distinct semiological feature that may signal a psychological vulnerability. We hypothesized that altered responsiveness is related to difficulties with emotion tolerance, experiential avoidance, difficulty coping, dissociation and trauma and prior experiences of loss of awareness. 71 patients with video-EEG confirmed PNES were divided into two groups based on their responsiveness at the time of the captured event during long-term monitoring. Demographic information, clinical history and self-rated questionnaires highlighting psychopathology were compared between the groups. 47 patients (66%) had altered responsiveness during their captured event. Married or partnered subjects were more represented in the altered responsiveness group. Experiential avoidance, as measured by the Acceptance and Action Questionnaire-II, and affect intolerance, as measured by the Affective Style Questionnaire, were significantly higher in the altered responsiveness group. The Connor Davidson Resilience Scale was significantly higher among intact responsiveness subjects. Subjects with altered responsiveness were more likely to have a family history of seizures, comorbid headaches, and loss of consciousness (LOC) during traumatic brain injury. There were no differences in measures of dissociation, somatization, mood or anxiety, or presence of psychiatric comorbidities, including PTSD or history of trauma. Altered responsiveness during PNES is a marker of lower emotional resilience or ability to tolerate emotions among patients with PNES. Emotion management may be an important therapeutic target for these patients. Prior experiences with LOC also contribute to the presence of altered responsiveness. Trauma and dissociation did not differentiate responsiveness during PNES. Copyright © 2017 British Epilepsy Association. All rights reserved.

Large perceptual distortions of locomotor action space occur in ground-based coordinates: Angular expansion and the large-scale horizontal-vertical illusion.

PubMed

Klein, Brennan J; Li, Zhi; Durgin, Frank H

2016-04-01

What is the natural reference frame for seeing large-scale spatial scenes in locomotor action space? Prior studies indicate an asymmetric angular expansion in perceived direction in large-scale environments: Angular elevation relative to the horizon is perceptually exaggerated by a factor of 1.5, whereas azimuthal direction is exaggerated by a factor of about 1.25. Here participants made angular and spatial judgments when upright or on their sides to dissociate egocentric from allocentric reference frames. In Experiment 1, it was found that body orientation did not affect the magnitude of the up-down exaggeration of direction, suggesting that the relevant orientation reference frame for this directional bias is allocentric rather than egocentric. In Experiment 2, the comparison of large-scale horizontal and vertical extents was somewhat affected by viewer orientation, but only to the extent necessitated by the classic (5%) horizontal-vertical illusion (HVI) that is known to be retinotopic. Large-scale vertical extents continued to appear much larger than horizontal ground extents when observers lay sideways. When the visual world was reoriented in Experiment 3, the bias remained tied to the ground-based allocentric reference frame. The allocentric HVI is quantitatively consistent with differential angular exaggerations previously measured for elevation and azimuth in locomotor space. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Large perceptual distortions of locomotor action space occur in ground-based coordinates: Angular expansion and the large-scale horizontal-vertical illusion

PubMed Central

Klein, Brennan J.; Li, Zhi; Durgin, Frank H.

2015-01-01

What is the natural reference frame for seeing large-scale spatial scenes in locomotor action space? Prior studies indicate an asymmetric angular expansion in perceived direction in large-scale environments: Angular elevation relative to the horizon is perceptually exaggerated by a factor of 1.5, whereas azimuthal direction is exaggerated by a factor of about 1.25. Here participants made angular and spatial judgments when upright or on their sides in order to dissociate egocentric from allocentric reference frames. In Experiment 1 it was found that body orientation did not affect the magnitude of the up-down exaggeration of direction, suggesting that the relevant orientation reference frame for this directional bias is allocentric rather than egocentric. In Experiment 2, the comparison of large-scale horizontal and vertical extents was somewhat affected by viewer orientation, but only to the extent necessitated by the classic (5%) horizontal-vertical illusion (HVI) that is known to be retinotopic. Large-scale vertical extents continued to appear much larger than horizontal ground extents when observers lay sideways. When the visual world was reoriented in Experiment 3, the bias remained tied to the ground-based allocentric reference frame. The allocentric HVI is quantitatively consistent with differential angular exaggerations previously measured for elevation and azimuth in locomotor space. PMID:26594884

Comparing the symptoms and mechanisms of "dissociation" in dissociative identity disorder and borderline personality disorder.

PubMed

Laddis, Andreas; Dell, Paul F; Korzekwa, Marilyn

2017-01-01

A total of 75 patients were diagnosed with the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised as having dissociative identity disorder (DID), and 100 patients were diagnosed with the Structured Interview for DSM-IV Personality as having borderline personality disorder (BPD). Both groups were administered the Multidimensional Inventory of Dissociation (MID). DID patients had significantly higher MID scores than BPD patients, different distributions of MID scores, and different MID subscale profiles in 3 ranges of MID scores (0-15, 15-30, 30-45). The core MID symptoms-exhibited at all ranges of MID scores-for DID patients (the presence of alters, identity confusion, and memory problems) and BPD patients (flashbacks, identity confusion, and memory problems) were ostensibly similar but were considered to be mostly produced by different underlying processes. Multiple regression analyses showed that the core MID symptoms of DID patients had different predictors than did the core MID symptoms of BPD patients. Alter identities seemed to generate most-but not all-dissociative phenomena in DID patients, whereas only the 24% highest scoring BPD patients (MID ≥45) seemed to manifest alter-driven dissociative experiences. Most BPD dissociative experiences appeared to be due to 5 other mechanisms: (a) BPD-specific, stress-driven, rapid shifts of self-state; (b and c) nondefensive disruptions of the framework of perceptual organization with or without an accompanying BPD-specific, dissociation-like disintegration of affective/neurocognitive functioning; (d) a defensive distancing or detachment from distress (i.e., simple depersonalization); and (e) Allen, Console, and Lewis's (1999) severe absorptive detachment.

Magical ideation -- defense mechanism or neuropathology? A study with multiple sclerosis patients.

PubMed

te Wildt, Bert Theodor; Schultz-Venrath, Ulrich

2004-01-01

The major psychological stress factor in multiple sclerosis (MS) is loss of control of life. In MS patients with impaired cognition, magical ideation might be a characteristic way of thinking. Proof for this may be the high frequency of alternative treatments used by individuals with MS. The study investigates whether the level of magical ideation in MS patients is higher compared to healthy control subjects and, in case of positive confirmation, with which somatic and psychological features it is associated. Moreover, it is aimed to discuss the modalities of magical ideation in general. A German version of the Magical Ideation Scale was validated with a group of 69 healthy subjects. Ninety-four MS patients were additionally assessed with the Dissociative Experience Scale, the Symptom-Check-List-90-Revised and 5 neuropsychological tests. The Magical Ideation Scale did not reveal a significant difference between MS patients and healthy controls (p = 0.968). Among the MS patients, magical ideation shows a correlation neither with age nor with disability, but a positive correlation (p = 0.007; r = 0.329) with the grade of neuropsychological deficiency. Among the psychological parameters, the highest positive correlation with magical ideation was found in dissociation (p = 0.000; r = 0.520). Magical ideation, sharing common features with dissociation, can be viewed as an early defense mechanism when perceiving a loss of control of life, particularly in early stages of MS. In late stages, when developing neuropsychological deficits, it may occur as a substitute for cognitive coping. The data may encourage clinicians to identify magical ideation. In young and previously diagnosed patients, it is important to acknowledge helplessness and support a rather rational way of coping. Training cognitive skills could be crucial to prevent older patients from losing touch with reality. More generally, the occurrence of a significant amount of magical ideation is discussed both as a psychological and a neurophysiologic regression of thinking. Copyright 2004 S. Karger AG, Basel

Dissociation: Defining the Concept in Criminal Forensic Psychiatry.

PubMed

Bourget, Dominique; Gagné, Pierre; Wood, Stephen Floyd

2017-06-01

Claims of amnesia and dissociative experiences in association with a violent crime are not uncommon. Research has shown that dissociation is a risk factor for violence and is seen most often in crimes of extreme violence. The subject matter is most relevant to forensic psychiatry. Peritraumatic dissociation for instance, with or without a history of dissociative disorder, is quite frequently reported by offenders presenting for a forensic psychiatric examination. Dissociation or dissociative amnesia for serious offenses can have legal repercussions stemming from their relevance to the legal constructs of fitness to stand trial, criminal responsibility, and diminished capacity. The complexity in forensic psychiatric assessments often lies in the difficulty of connecting clinical symptomatology reported by violent offenders to a specific condition included in the Diagnostic and Statistical Manual of Mental Disorders (DSM). This article provides a review of diagnostic considerations with regard to dissociation across the DSM nomenclature, with a focus on the main clinical constructs related to dissociation. Forensic implications are discussed, along with some guides for the forensic evaluator of offenders presenting with dissociation. © 2017 American Academy of Psychiatry and the Law.

Peritraumatic tonic immobility is associated with PTSD symptom severity in Brazilian police officers: a prospective study.

PubMed

Maia, Deborah B; Nóbrega, Augusta; Marques-Portella, Carla; Mendlowicz, Mauro V; Volchan, Eliane; Coutinho, Evandro S; Figueira, Ivan

2015-01-01

Peritraumatic reactions feature prominently among the main predictors for development of posttraumatic stress disorder (PTSD). Peritraumatic tonic immobility (PTI), a less investigated but equally important type of peritraumatic response, has been recently attracting the attention of researchers and clinicians for its close association with traumatic reactions and PTSD. Our objective was to investigate the role of PTI, peritraumatic panic, and dissociation as predictors of PTSD symptoms in a cohort of police recruits (n=132). Participants were asked to complete the following questionnaires during academy training and after the first year of work: Posttraumatic Stress Disorder Checklist - Civilian Version (PCL-C), Physical Reactions Subscale (PRS), Peritraumatic Dissociative Experiences Questionnaire (PDEQ), Tonic Immobility Scale (TIS), and Critical Incident History Questionnaire. Employing a zero-inflated negative binomial regression model, we found that each additional point in the TIS was associated with a 9% increment in PCL-C mean scores (RM = 1.09), whereas for PRS, the increment was 7% (RM = 1.07). As the severity of peritraumatic dissociation increased one point in the PDEQ, the chance of having at least one symptom in the PCL-C increased 22% (OR = 1.22). Our findings highlight the need to expand investigation on the incidence and impact of PTI on the mental health of police officers.

Dissociation as a mediator of the relationship between childhood trauma and nonsuicidal self-injury in females: a path analytic approach.

PubMed

Franzke, Iris; Wabnitz, Pascal; Catani, Claudia

2015-01-01

New theoretical models of nonsuicidal self-injury (NSSI) postulate that symptoms subsequent to childhood maltreatment rather than childhood maltreatment itself may lead to engagement in NSSI. However, little is known concerning which specific syndromes serve as underlying mechanisms. In this study we sought to examine the mediating effects of dissociative, posttraumatic, and depressive symptoms, 3 often comorbid syndromes following childhood trauma. In addition, we aimed to assess differences between women with and without NSSI. A sample of 87 female inpatients with a history of childhood abuse and neglect was divided into 2 subgroups (NSSI: n = 42, no NSSI: n = 45). The assessment included measures of NSSI characteristics; adverse childhood experiences; and posttraumatic, dissociative, and depressive symptoms. The NSSI group reported significantly more cases of childhood maltreatment and higher levels of current dissociative, posttraumatic, and depressive symptoms than patients without NSSI. The results of a path analysis showed that only dissociation mediated the relationship between a history of child maltreatment and NSSI when all 3 psychopathological variables were included in the model. The findings point toward a strong and rather specific association between dissociative experiences and NSSI and therefore have important implications for clinical practice.

Experiences of possession and paranormal phenomena among women in the general population: are they related to traumatic stress and dissociation?

PubMed

Sar, Vedat; Alioğlu, Firdevs; Akyüz, Gamze

2014-01-01

This study sought to determine the prevalence of experiences of possession and paranormal phenomena (PNP) in the general population and their possible relations to each other and to traumatic stress and dissociation. The study was conducted on a representative female sample recruited from a town in central eastern Turkey. The Dissociative Disorders Interview Schedule, the posttraumatic stress disorder (PTSD) and borderline personality disorder sections of the Structured Clinical Interviews for DSM-IV Axis-I and Personality Disorders, and the Childhood Abuse and Neglect Questionnaire were administered to 628 women. Of these, 127 (20.2%) women reported at least 1 type of PNP and 13 (2.1%) women reported possession. Women with a dissociative disorder reported all types of possession and PNP (except telepathy) more frequently than those without. Whereas women with a trauma history in childhood and adulthood or PTSD reported possession more frequently than those without, PNP were associated with childhood trauma only. Factor analysis yielded 4 dimensions: possession by and/or contact with nonhuman entities, extrasensory communications, possession by a human entity, and precognition. These factors correlated with number of secondary features of dissociative identity disorder and Schneiderian symptoms. Latent class analysis identified 3 groups. The most traumatized group, with predominantly dissociative and trauma-related disorders, had the highest scores on all factors. Notwithstanding their presence in healthy individuals, possession and PNP were associated with trauma and dissociation in a subgroup of affected participants. Both types of experience seem to be normal human capacities of experiencing that may be involved in response to traumatic stress. Given the small numbers, this study should be considered preliminary.

The role of clinical experience, diagnosis, and theoretical orientation in the treatment of posttraumatic and dissociative disorders: A vignette and survey investigation.

PubMed

Dorahy, Martin J; Lewis-Fernández, Roberto; Krüger, Christa; Brand, Bethany L; Şar, Vedat; Ewing, Jan; Martínez-Taboas, Alfonso; Stavropoulos, Pam; Middleton, Warwick

2017-01-01

Controversy exists regarding the merits of exposure-based treatments for posttraumatic stress disorder (PTSD) versus a phased approach when prominent dissociative symptoms are present. The first aim of this study was to examine the degree to which diagnosing dissociation in two traumatized patients' vignettes influenced clinicians' preference for phase-oriented treatment and whether clinicians' treatment experience contributed to their treatment preference. The second aim was to assess the extent to which participants had observed traumatized patients worsen when treated with exposure therapy or phase-oriented therapy and whether the theoretical orientation and treatment experience of the clinician were related to the observed deterioration. In the tradition of expert and practitioner surveys, 263 clinicians completed a survey of their diagnoses and treatment preferences for two vignettes and their treatment experience, theoretical orientation, and observations of patients' deterioration. When a marked degree of dissociation was noted in the PTSD vignette, respondents favored phased approaches regardless of the diagnosis given. Reports of having observed patient deterioration during both exposure and phased therapy were predicted by years of experience. Psychodynamic therapists reported more observations of worsening during exposure therapy than cognitive behavior therapy therapists. Clinical experience treating PTSD may heighten awareness of negative therapeutic effects, potentially because experienced clinicians have a lower threshold for detecting such effects and because they are referred more challenging cases.

Muscle dysmorphia and psychopathology: Findings from an Italian sample of male bodybuilders.

PubMed

Longobardi, Claudio; Prino, Laura Elvira; Fabris, Matteo Angelo; Settanni, Michele

2017-10-01

The aim of this study is to investigate the relationship between the risk of muscle dysmorphia and psychopathological symptoms in an Italian sample of male bodybuilders. The sample was recruited online (145 men with a mean age of 30.0 years) and participants were asked to fill out the Muscle Dysmorphic Disorder Inventory (MDDI), Symptom Cheklist-90-R (SCL-90-R), Dissociative Experiences Scale (DES-II), and to provide other socio-demographic data. Bodybuilders at risk of muscle dysmorphia display greater global psychopathology and present higher scores on all SCL-90-R dimensions when compared to bodybuilders not at risk of muscle dysmorphia. Furthermore, risk of muscle dysmorphia is positively associated to dissociative symptoms. The Competitiveness dimension and anabolic steroid intake were not related to muscle dysmorphia, while age appeared to be more significant. Findings are discussed based upon previous studies and directions for future research are suggested. Copyright © 2017 Elsevier B.V. All rights reserved.

Going the distance: spatial scale of athletic experience affects the accuracy of path integration.

PubMed

Smith, Alastair D; Howard, Christina J; Alcock, Niall; Cater, Kirsten

2010-09-01

Evidence suggests that athletically trained individuals are more accurate than untrained individuals in updating their spatial position through idiothetic cues. We assessed whether training at different spatial scales affects the accuracy of path integration. Groups of rugby players (large-scale training) and martial artists (small-scale training) participated in a triangle-completion task: they were led (blindfolded) along two sides of a right-angled triangle and were required to complete the hypotenuse by returning to the origin. The groups did not differ in their assessment of the distance to the origin, but rugby players were more accurate than martial artists in assessing the correct angle to turn (heading), and landed significantly closer to the origin. These data support evidence that distance and heading components can be dissociated. Furthermore, they suggest that the spatial scale at which an individual is trained may affect the accuracy of one component of path integration but not the other.

Ionization dynamics of the water trimer: A direct ab initio MD study

NASA Astrophysics Data System (ADS)

Tachikawa, Hiroto; Takada, Tomoya

2013-03-01

Ionization dynamics of the cyclic water trimer (H2O)3 have been investigated by means of direct ab initio molecular dynamics (AIMD) method. Two reaction channels, complex formation and OH dissociation, were found following the ionization of (H2O)3. In both channels, first, a proton was rapidly transferred from H2O+ to H2O (time scale is ˜15 fs after the ionization). In complex channel, an ion-radical contact pair (H3O+-OH) solvated by the third water molecule was formed as a long-lived H3O+(OH)H2O complex. In OH dissociation channel, the second proton transfer further takes place from H3O+(OH) to H2O (time scale is 50-100 fs) and the OH radical is separated from the H3O+. At the same time, the OH dissociation takes place when the excess energy is efficiently transferred into the kinetic energy of OH radical. The OH dissociation channel is significantly minor, and almost all product channels were the complex formation. The reaction mechanism was discussed on the basis of theoretical results.

The generation of O(1S) from the dissociative recombination of O2(+)

NASA Technical Reports Server (NTRS)

Guberman, Steven L.; Giusti-Suzor, Annick

1991-01-01

The multichannel quantum defect theory (MQDT) method and large scale wave functions are applied to the calculation of the cross sections and rates for dissociative recombination of O2(+) along the 1Sigma-u(+) dissociative potential. Indirect dissociative recombination is accounted for by simultaneously including both the vibronic and electronic coupling to the intermediate Rydberg resonances. An enhanced MQDT approach involving a second-order K matrix is described. Cross sections and rates for the lowest three vibrational levels of the ion are reported. The shapes of the cross sections are discussed in terms of Fano's profile index. It is found that, for each of the three ion vibrational levels, the intermediate Rydberg resonances reduce the dissociative recombination rate below the direct recombination rate. Just above threshold, resonances with centers below threshold play an important role.

Unformulated experience, dissociation, and Nachträglichkeit.

PubMed

Stern, Donnel B

2017-09-01

The paper is divided into two parts. The first part is an interpersonal/relational psychoanalytic account of some relationships between dissociation, time, and unformulated experience. Trauma, and the dissociation to which trauma leads, freezes time, which makes it impossible to formulate certain kinds of new experience. Instead, potential new meanings remain unformulated. The route of clinical access to frozen time is the interpersonal field: to thaw time and allow new experience, the ways in which the interpersonal field is itself frozen need to be addressed. A clinical illustration of these ideas is offered. The second part of the paper presents and explores a point of confluence between the views in Part 1 and certain aspects of French psychoanalysis, with particular reference to the concept of Nachträglichkeit in the work of Jean Laplanche and Haydée Faimberg. © 2017, The Society of Analytical Psychology.

Dissociative tendencies and individual differences in high hypnotic suggestibility.

PubMed

Terhune, Devin Blair; Cardeña, Etzel; Lindgren, Magnus

2011-03-01

Inconsistencies in the relationship between dissociation and hypnosis may result from heterogeneity among highly suggestible individuals, in particular the existence of distinct highly suggestible subtypes that are of relevance to models of psychopathology and the consequences of trauma. This study contrasted highly suggestible subtypes high or low in dissociation on measures of hypnotic responding, cognitive functioning, and psychopathology. Twenty-one low suggestible (LS), 19 low dissociative highly suggestible (LDHS), and 11 high dissociative highly suggestible (HDHS) participants were administered hypnotic suggestibility scales and completed measures of free recall, working memory capacity, imagery, fantasy-proneness, psychopathology, and exposure to stressful life events. HDHS participants were more responsive to positive and negative hallucination suggestions and experienced greater involuntariness during hypnotic responding. They also exhibited impaired working memory capacity, elevated pathological fantasy and dissociative symptomatology, and a greater incidence of exposure to stressful life events. In contrast, LDHS participants displayed superior object visual imagery. These results provide further evidence for two highly suggestible subtypes: a dissociative subtype characterised by deficits in executive functioning and a predisposition to psychopathology, and a subtype that exhibits superior imagery and no observable deficits in functioning.

The co-occurrence of PTSD and dissociation: differentiating severe PTSD from dissociative-PTSD.

PubMed

Armour, Cherie; Karstoft, Karen-Inge; Richardson, J Don

2014-08-01

A dissociative-posttraumatic stress disorder (PTSD) subtype has been included in the DSM-5. However, it is not yet clear whether certain socio-demographic characteristics or psychological/clinical constructs such as comorbid psychopathology differentiate between severe PTSD and dissociative-PTSD. The current study investigated the existence of a dissociative-PTSD subtype and explored whether a number of trauma and clinical covariates could differentiate between severe PTSD alone and dissociative-PTSD. The current study utilized a sample of 432 treatment seeking Canadian military veterans. Participants were assessed with the Clinician Administered PTSD Scale (CAPS) and self-report measures of traumatic life events, depression, and anxiety. CAPS severity scores were created reflecting the sum of the frequency and intensity items from each of the 17 PTSD and 3 dissociation items. The CAPS severity scores were used as indicators in a latent profile analysis (LPA) to investigate the existence of a dissociative-PTSD subtype. Subsequently, several covariates were added to the model to explore differences between severe PTSD alone and dissociative-PTSD. The LPA identified five classes: one of which constituted a severe PTSD group (30.5 %), and one of which constituted a dissociative-PTSD group (13.7 %). None of the included, demographic, trauma, or clinical covariates were significantly predictive of membership in the dissociative-PTSD group compared to the severe PTSD group. In conclusion, a significant proportion of individuals report high levels of dissociation alongside their PTSD, which constitutes a dissociative-PTSD subtype. Further investigation is needed to identify which factors may increase or decrease the likelihood of membership in a dissociative-PTSD subtype group compared to a severe PTSD only group.

Relations of mindfulness facets with psychological symptoms among individuals with a diagnosis of obsessive-compulsive disorder, major depressive disorder, or borderline personality disorder.

PubMed

Didonna, Fabrizio; Rossi, Roberta; Ferrari, Clarissa; Iani, Luca; Pedrini, Laura; Rossi, Nicoletta; Xodo, Erica; Lanfredi, Mariangela

2018-03-25

To explore differences in mindfulness facets among patients with a diagnosis of either obsessive-compulsive disorder (OCD), major depressive disorder (MDD), or borderline personality disorder (BPD), and healthy controls (HC), and their associations with clinical features. One hundred and fifty-three patients and 50 HC underwent a clinical assessment including measures of mindfulness (Five Facets Mindfulness Questionnaire - FFMQ), psychopathological symptoms (Symptom Check List-90-R), dissociation (Dissociative Experience Scale), alexithymia (Alexithymia Scale 20), and depression (Beck Depression Inventory-II). Analysis of variance (ANOVA) and analysis of covariance (ANCOVA) were performed to assess differences in mindfulness scores and their associations with clinical features. The three diagnostic groups scored lower on all mindfulness facets (apart from FFMQobserving) compared to the HC group. OCD group had a significant higher FFMQ total score (FFMQ-TS) and FFMQacting with awareness compared to the BPD group, and scored higher on FFMQdescribing compared to BPD and MDD groups. The scores in non-judging facet were significantly lower in all the three diagnostic groups compared to the HC group. Interestingly, higher FFMQ-TS was inversely related to all psychological measures, regardless of diagnostic group. Deficits in mindfulness skills were present in all diagnostic groups. Furthermore, we found disease-specific relationships between some mindfulness facets and specific psychological variables. Clinical implications are discussed. The study showed deficits in mindfulness scores in all diagnostic groups compared to a healthy control group. Overall, mindfulness construct has a significantly negative association with indexes of global distress, dissociative symptoms, alexithymia, and depression. Mindfulness-based interventions in clinical settings should take into account different patterns of mindfulness skills and their impact on disease-specific maladaptive cognitive strategies or symptomatology. © 2018 The British Psychological Society.

Schizophrenia, dissociative anaesthesia and near-death experience; three events meeting at the NMDA receptor.

PubMed

Bonta, Iván L

2004-01-01

The three events, viz. schizophrenia, dissociative anaesthesia and Near-Death Experience, despite their seemingly unrelated manifestation to each other, have nevertheless similar functional basis. All three events are linked to the glutamate sensitive N-methyl-D-aspartate (NMDA) receptor complex, which serves as their common functional denominator. Arguments and speculations are presented in favor of the view that, the three events might be considered as functional models of each other. Antagonism to the recognition NMDA-site of the receptor induces dissociative anaesthesia and precipitates Near-Death Experience. Agonist reinforcement at the modulatory glycine-site of the receptor counteracts negative symptoms of schizophrenia. Both types of challenges towards the receptor are compatible with a glutamate deficiency concept which underlies the meeting of the three events at the NMDA receptor.

The effect of pre-existing vulnerability factors on a laboratory analogue trauma experience.

PubMed

Laposa, Judith M; Alden, Lynn E

2008-12-01

This study examined how pre-existing emotional and personality vulnerability factors affect responses to an analogue trauma experience. Sixty-eight undergraduate participants viewed a distressing film and completed measures of trait anxiety, intelligence, depression, trait dissociation, as well as changes in state anxiety, then recorded intrusions over the following week. Results revealed that trait anxiety, depression, trait dissociation, change in anxiety, and post-state anxiety were associated with intrusion frequency. Post-state anxiety mediated the relationship between trait anxiety, depression and trait dissociation, and intrusions. Implications for PTSD theories and laboratory trauma analogue research examining specific elements of cognitive models of PTSD are discussed.

Establishing and running a trauma and dissociation unit: a contemporary experience.

PubMed

Middleton, Warwick; Higson, David

2004-12-01

To evaluate the functioning of a trauma and dissociation unit that has run for the past 8 years in a private hospital, with particular regard to operating philosophy, operating parameters, challenges encountered, research and educational initiatives, and the applicability of the treatment model to other settings. Despite the challenges associated with significant difficulties in the corporate management of a private health-care system, it has been possible to operate an inpatient and day hospital programme tailored to the needs of patients in the dissociative spectrum, and the lessons learnt from this experience are valid considerations in the future planning of mental health services overall.

Kinetic method for the large-scale analysis of the binding mechanism of histone deacetylase inhibitors.

PubMed

Meyners, Christian; Baud, Matthias G J; Fuchter, Matthew J; Meyer-Almes, Franz-Josef

2014-09-01

Performing kinetic studies on protein ligand interactions provides important information on complex formation and dissociation. Beside kinetic parameters such as association rates and residence times, kinetic experiments also reveal insights into reaction mechanisms. Exploiting intrinsic tryptophan fluorescence a parallelized high-throughput Förster resonance energy transfer (FRET)-based reporter displacement assay with very low protein consumption was developed to enable the large-scale kinetic characterization of the binding of ligands to recombinant human histone deacetylases (HDACs) and a bacterial histone deacetylase-like amidohydrolase (HDAH) from Bordetella/Alcaligenes. For the binding of trichostatin A (TSA), suberoylanilide hydroxamic acid (SAHA), and two other SAHA derivatives to HDAH, two different modes of action, simple one-step binding and a two-step mechanism comprising initial binding and induced fit, were verified. In contrast to HDAH, all compounds bound to human HDAC1, HDAC6, and HDAC8 through a two-step mechanism. A quantitative view on the inhibitor-HDAC systems revealed two types of interaction, fast binding and slow dissociation. We provide arguments for the thesis that the relationship between quantitative kinetic and mechanistic information and chemical structures of compounds will serve as a valuable tool for drug optimization. Copyright © 2014 Elsevier Inc. All rights reserved.

The interplay of cannabinoid and NMDA glutamate receptor systems in humans: preliminary evidence of interactive effects of cannabidiol and ketamine in healthy human subjects.

PubMed

Hallak, Jaime E C; Dursun, Serdar M; Bosi, Daniel C; de Macedo, Ligia Ribeiro Horta; Machado-de-Sousa, João Paulo; Abrão, João; Crippa, José A S; McGuire, Phillip; Krystal, John H; Baker, Glen B; Zuardi, Antonio W

2011-01-15

Interactions between glutamatergic and endocannabinoid systems may contribute to schizophrenia, dissociative states, and other psychiatric conditions. Cannabidiol (CBD), a cannabinoid-1/2 (CB1/2) receptor weak partial agonist or antagonist, may play a role in the treatment of schizophrenia. This study tested the hypothesis that CBD would attenuate the behavioral effects of the NMDA receptor antagonist, ketamine, in healthy human subjects. Ten male healthy volunteers were evaluated twice in a randomized order. In both sessions they received ketamine (bolus of 0.26 mg/kg/1 min followed by IV infusion of 0.25mg/kg over 30 min) preceded by either CBD (600 mg) or placebo. Psychopathology was assessed using the Brief Psychiatric Rating Scale (BPRS) and the CADSS (Clinician Administered Dissociative States Scale) at regular intervals from 30 min before to 90 min after ketamine administration. CBD significantly augmented the activating effects of ketamine, as measured by the activation subscales of the BPRS. However, CBD also showed a non-significant trend to reduce ketamine-induced depersonalization, as measured by the CADSS. These data describe a complex pattern of psychopharmacologic interactions between CBD and ketamine at the doses of each agent studied in this experiment. Copyright © 2010 Elsevier B.V. All rights reserved.

Dissociating motivation from reward in human striatal activity.

PubMed

Miller, Eric M; Shankar, Maya U; Knutson, Brian; McClure, Samuel M

2014-05-01

Neural activity in the striatum has consistently been shown to scale with the value of anticipated rewards. As a result, it is common across a number of neuroscientific subdiscliplines to associate activation in the striatum with anticipation of a rewarding outcome or a positive emotional state. However, most studies have failed to dissociate expected value from the motivation associated with seeking a reward. Although motivation generally scales positively with increases in potential reward, there are circumstances in which this linkage does not apply. The current study dissociates value-related activation from that induced by motivation alone by employing a task in which motivation increased as anticipated reward decreased. This design reverses the typical relationship between motivation and reward, allowing us to differentially investigate fMRI BOLD responses that scale with each. We report that activity scaled differently with value and motivation across the striatum. Specifically, responses in the caudate and putamen increased with motivation, whereas nucleus accumbens activity increased with expected reward. Consistent with this, self-report ratings indicated a positive association between caudate and putamen activity and arousal, whereas activity in the nucleus accumbens was more associated with liking. We conclude that there exist regional limits on inferring reward expectation from striatal activation.

Dissociating Motivation from Reward in Human Striatal Activity

PubMed Central

Miller, Eric M.; Shankar, Maya U.; Knutson, Brian; McClure, Samuel M.

2018-01-01

Neural activity in the striatum has consistently been shown to scale with the value of anticipated rewards. As a result, it is common across a number of neuroscientific subdiscliplines to associate activation in the striatum with anticipation of a rewarding outcome or a positive emotional state. However, most studies have failed to dissociate expected value from the motivation associated with seeking a reward. Although motivation generally scales positively with increases in potential reward, there are circumstances in which this linkage does not apply. The current study dissociates value-related activation from that induced by motivation alone by employing a task in which motivation increased as anticipated reward decreased. This design reverses the typical relationship between motivation and reward, allowing us to differentially investigate fMRI BOLD responses that scale with each. We report that activity scaled differently with value and motivation across the striatum. Specifically, responses in the caudate and putamen increased with motivation, whereas nucleus accumbens activity increased with expected reward. Consistent with this, self-report ratings indicated a positive association between caudate and putamen activity and arousal, whereas activity in the nucleus accumbens was more associated with liking. We conclude that there exist regional limits on inferring reward expectation from striatal activation. PMID:24345173

Clandestine psychopathology: unrecognized dissociative disorders in inpatient psychiatry.

PubMed

Ginzburg, Karni; Somer, Eli; Tamarkin, Gali; Kramer, Lilach

2010-05-01

Surveys among Israeli mental health professionals found that almost half of them doubt the validity of dissociative disorders (DD) and have no experience in either diagnosing or treating DD patients. These findings, in line with arguments that DDs are socially construed North American phenomena, call for the need to investigate it in Israel. Eighty-one psychiatric inpatients were screened for dissociative pathology. Participants categorized as having low levels of dissociation (n = 26) and those demonstrating high levels of dissociation (n = 22) were asked to participate in a Structured Clinical Interview for the DSM-Dissociative Disorders-Revised. One-quarter of all participants were identified as having probable dissociative psychopathology. Based on the Structured Clinical Interview for the DSM-Dissociative Disorders-Revised, estimates of DD range between 12 and 21%. None of the participants had any indication of a DD diagnosis in their medical records. Diagnosis of personality disorder and psychiatric comorbidity were related to the likelihood of a DD diagnosis and its severity.

Electron transfer dissociation (ETD): The mass spectrometric breakthrough essential for O-GlcNAc protein site assignments – A study of the O-GlcNAcylated protein Host Cell Factor C1

PubMed Central

Myers, Samuel A.; Daou, Salima; Affar, El Bachir; Burlingame, AL

2014-01-01

The development of electron-based, unimolecular dissociation mass spectrometric methods, i.e. electron capture and electron transfer dissociation (ECD and ETD, respectively), has greatly increased the speed and reliability of labile post-translational modification (PTM) site assignment. The field of intracellular O-GlcNAc (O-linked N-acetylglucosamine) signaling has especially advanced with the advent of ETD mass spectrometry. Only within the last five years have proteomic-scale experiments utilizing ETD allowed the assignment of hundreds of O-GlcNAc sites within cells and subcellular structures. Our ability to identify and unambiguously assign the site of O-GlcNAc modifications using ETD is rapidly increasing our understanding of this regulatory glycosylation and its potential interaction with other PTMs. Here, we discuss the advantages of using ETD, complimented with collisional-activation mass spectrometry (CID/CAD), in a study of O-GlcNAc modified peptides of the extensively O-GlcNAcylated protein Host Cell Factor C1 (HCF-1). HCF-1 is a transcriptional co-regulator, forms a stable complex with O-GlcNAc transferase and is involved in control of cell cycle progression. ETD, along with higher energy collisional dissociation (HCD) mass spectrometry, was employed to assign the PTMs of the HCF-1 protein isolated from HEK293T cells. These include nineteen sites of O-GlcNAcylation, two sites of phosphorylation and two sites bearing dimethylarginine, and showcase the residue-specific, PTM complexity of this regulator of cell proliferation. PMID:23335398

Thermal regulation of methane hydrate dissociation: Implications for gas production models

USGS Publications Warehouse

Circone, S.; Kirby, S.H.; Stern, L.A.

2005-01-01

Thermal self-regulation of methane hydrate dissociation at pressure, temperature conditions along phase boundaries, illustrated by experiment in this report, is a significant effect with potential relevance to gas production from gas hydrate. In surroundings maintained at temperatures above the ice melting point, the temperature in the vicinity of dissociating methane hydrate will decrease because heat flow is insufficient to balance the heat absorbed by the endothermic reaction: CH4??nH2O (s) = CH4 (g) + nH2O (l). Temperature decreases until either all of the hydrate dissociates or a phase boundary is reached. At pressures above the quadruple point, the temperature-limiting phase boundary is that of the dissociation reaction itself. At lower pressures, the minimum temperature is limited by the H2O solid/liquid boundary. This change in the temperature-limiting phase boundary constrains the pressure, temperature conditions of the quadruple point for the CH4-H2O system to 2.55 ?? 0.02 MPa and 272.85 ?? 0.03 K. At pressures below the quadruple point, hydrate dissociation proceeds as the liquid H2O produced by dissociation freezes. In the laboratory experiments, dissociation is not impeded by the formation of ice byproduct per se; instead rates are proportional to the heat flow from the surroundings. This is in contrast to the extremely slow dissociation rates observed when surrounding temperatures are below the H2O solid/liquid boundary, where no liquid water is present. This "anomalous" or "self" preservation behavior, most pronounced near 268 K, cannot be accessed when surrounding temperatures are above the H2O solid/liquid boundary. ?? 2005 American Chemical Society.

The effect of elevated methane pressure on methane hydrate dissociation

USGS Publications Warehouse

Circone, S.; Stern, L.A.; Kirby, S.H.

2004-01-01

Methane hydrate, equilibrated at P, T conditions within the hydrate stability field, was rapidly depressurized to 1.0 or 2.0 MPa and maintained at isobaric conditions outside its stability field, while the extent and rate of hydrate dissociation was measured at fixed, externally maintained temperatures between 250 and 288 K. The dissociation rate decreases with increasing pressure at a given temperature. Dissociation rates at 1.0 MPa parallel the complex, reproducible T-dependence previously observed between 250 and 272 K at 0.1 MPa. The lowest rates were observed near 268 K, such that >50% of the sample can persist for more than two weeks at 0.1 MPa to more than a month at 1 and 2 MPa. Varying the pressure stepwise in a single experiment increased or decreased the dissociation rate in proportion to the rates observed in the isobaric experiments, similar to the rate reversibility previously observed with stepwise changes in temperature at 0.1 MPa. At fixed P, T conditions, the rate of methane hydrate dissociation decreases monotonically with time, never achieving a steady rate. The relationship between time (t) and the extent of hydrate dissociation is empirically described by: Evolved gas (%) = A??tB where the pre-exponential term A ranges from 0 to 16% s-B and the exponent B is generally <1. Based on fits of the dissociation results to Equation 1 for the full range of temperatures (204 to 289 K) and pressures (0.1 to 2.0 MPa) investigated, the derived parameters can be used to predict the methane evolution curves for pure, porous methane hydrate to within ??5%. The effects of sample porosity and the presence of quartz sand and seawater on methane hydrate dissociation are also described using Equation 1.

Threshold collision-induced dissociation of diatomic molecules: a case study of the energetics and dynamics of O2- collisions with Ar and Xe.

PubMed

Ahu Akin, F; Ree, Jongbaik; Ervin, Kent M; Kyu Shin, Hyung

2005-08-08

The energetics and dynamics of collision-induced dissociation of O2- with Ar and Xe targets are studied experimentally using guided ion-beam tandem mass spectrometry. The cross sections and the collision dynamics are modeled theoretically by classical trajectory calculations. Experimental apparent threshold energies are 2.1 and 1.1 eV in excess of the thermochemical O2- bond dissociation energy for argon and xenon, respectively. Classical trajectory calculations confirm the observed threshold behavior and the dependence of cross sections on the relative kinetic energy. Representative trajectories reveal that the bond dissociation takes place on a short time scale of about 50 fs in strong direct collisions. Collision-induced dissociation is found to be remarkably restricted to the perpendicular approach of ArXe to the molecular axis of O2-, while collinear collisions do not result in dissociation. The higher collisional energy-transfer efficiency of xenon compared with argon is attributed to both mass and polarizability effects.

Women With Dissociative Identity Disorder Who Experience Intimate Partner Violence.

PubMed

Snyder, Briana L

2018-05-01

Women with dissociative identity disorder (DID) are significantly more likely than other women to experience intimate partner violence (IPV). The purpose of this qualitative investigation was to explicate the experiences of women with DID who experience IPV and describe how they cope. Grounded theory was used to conduct this investigation. Purposive sampling was used to recruit participants (N = 5) for face-to-face, semi-structured interviews. Verbatim transcripts were coded and categorized, and reflective memos were developed to explicate substantive categories. Women with DID used coping strategies that were consistent with their diagnoses, such as switching and dissociating. These coping mechanisms reflect past self-preservation strategies that were developed in association with severe childhood maltreatment. Women with DID who experienced IPV sought to mitigate and safeguard themselves from danger using strategies they developed as maltreated children. Nurses can use these findings to better recognize and understand the motivations and behaviors of women with DID who experience IPV. [Journal of Psychosocial Nursing and Mental Health Services, 56(5), 26-32.]. Copyright 2018, SLACK Incorporated.

Visuomotor Dissociation in Cerebral Scaling of Size.

PubMed

Potgieser, Adriaan R E; de Jong, Bauke M

2016-01-01

Estimating size and distance is crucial in effective visuomotor control. The concept of an internal coordinate system implies that visual and motor size parameters are scaled onto a common template. To dissociate perceptual and motor components in such scaling, we performed an fMRI experiment in which 16 right-handed subjects copied geometric figures while the result of drawing remained out of sight. Either the size of the example figure varied while maintaining a constant size of drawing (visual incongruity) or the size of the examples remained constant while subjects were instructed to make changes in size (motor incongruity). These incongruent were compared to congruent conditions. Statistical Parametric Mapping (SPM8) revealed brain activations related to size incongruity in the dorsolateral prefrontal and inferior parietal cortex, pre-SMA / anterior cingulate and anterior insula, dominant in the right hemisphere. This pattern represented simultaneous use of a 'resized' virtual template and actual picture information requiring spatial working memory, early-stage attention shifting and inhibitory control. Activations were strongest in motor incongruity while right pre-dorsal premotor activation specifically occurred in this condition. Visual incongruity additionally relied on a ventral visual pathway. Left ventral premotor activation occurred in all variably sized drawing while constant visuomotor size, compared to congruent size variation, uniquely activated the lateral occipital cortex additional to superior parietal regions. These results highlight size as a fundamental parameter in both general hand movement and movement guided by objects perceived in the context of surrounding 3D space.

An Archetype of the Collaborative Efforts of Psychotherapy and Psychopharmacology in Successfully Treating Dissociative Identity Disorder with Comorbid Bipolar Disorder

PubMed Central

Lakshmanan, Manu N.; Meier, Stacey L. Colton; Meier, Robert S.

2010-01-01

We present a case where dissociative identity disorder was effectively treated with memory retrieval psychotherapy. However, the patient’s comorbid bipolar disorder contributed to the patient’s instability and fortified the amnesiac barriers that exist between alter personality states in dissociative identity disorder, which made memory retrieval difficult to achieve. Implications from this case indicate that a close collaboration between psychologist and psychiatrist focused on carefully diagnosing and treating existing comorbid conditions may be the most important aspect in treating dissociative identity disorder. We present our experience of successfully treating a patient with dissociative identity disorder and bipolar disorder using this collaborative method. PMID:20805917

An archetype of the collaborative efforts of psychotherapy and psychopharmacology in successfully treating dissociative identity disorder with comorbid bipolar disorder.

PubMed

Lakshmanan, Manu N; Meier, Stacey L Colton; Meier, Robert S; Lakshmanan, Ramaswamy

2010-07-01

We present a case where dissociative identity disorder was effectively treated with memory retrieval psychotherapy. However, the patient's comorbid bipolar disorder contributed to the patient's instability and fortified the amnesiac barriers that exist between alter personality states in dissociative identity disorder, which made memory retrieval difficult to achieve. Implications from this case indicate that a close collaboration between psychologist and psychiatrist focused on carefully diagnosing and treating existing comorbid conditions may be the most important aspect in treating dissociative identity disorder. We present our experience of successfully treating a patient with dissociative identity disorder and bipolar disorder using this collaborative method.

Dissociative Experiences and Disorders among Women Who Identify Themselves as Sexual Abuse Survivors.

ERIC Educational Resources Information Center

Anderson, Geri; And Others

1993-01-01

Interviews with 51 female sexual abuse survivors revealed that over half had a diagnosis of multiple personality disorder, and the vast majority had extensive dissociative symptomatology and related features. (Author/JDD)

Psychophysiology of dissociated consciousness.

PubMed

Bob, Petr

2014-01-01

Recent study of consciousness provides an evidence that there is a limit of consciousness, which presents a barrier between conscious and unconscious processes. This barrier likely is specifically manifested as a disturbance of neural mechanisms of consciousness that through distributed brain processing, attentional mechanisms and memory processes enable to constitute integrative conscious experience. According to recent findings a level of conscious integration may change during certain conditions related to experimental cognitive manipulations, hypnosis, or stressful experiences that can lead to dissociation of consciousness. In psychopathological research the term dissociation was proposed by Pierre Janet for explanation of processes related to splitting of consciousness due to traumatic events or during hypnosis. According to several recent findings dissociation of consciousness likely is related to deficits in global distribution of information and may lead to heightened levels of "neural complexity" that reflects brain integration or differentiation based on numbers of independent neural processes in the brain that may be specifically related to various mental disorders.

A causal model explaining the relationships governing beliefs, attitudes, and hypnotic responsiveness.

PubMed

Shimizu, Takahiro

2014-01-01

The author developed a new scale aimed at measuring beliefs about "hypnotic states" and investigated the influence of such beliefs and attitudes on hypnotic responses in a large sample of Japanese undergraduate students. Exploratory factor analysis of this new questionnaire examining beliefs about hypnotic states yielded four factors: Dissociative or Depersonalized Experience, Loss of Self-Control, Therapeutic Expectation, and Arousing Extraordinary Ability. The results of structural equation modeling showed that Therapeutic Expectation and Arousing Extraordinary Ability influenced hypnotizability through attitudes toward hypnosis, while also directly affecting subjective experiences without mediating attitudes. Present findings suggest that it is more effective to enhance therapeutic expectations than to correct misconceptions about hypnotic states in modification of patients' beliefs before initiating treatment.

Dissociative disorders in DSM-5.

PubMed

Spiegel, David; Loewenstein, Richard J; Lewis-Fernández, Roberto; Sar, Vedat; Simeon, Daphne; Vermetten, Eric; Cardeña, Etzel; Brown, Richard J; Dell, Paul F

2011-12-21

We present recommendations for revision of the diagnostic criteria for the Dissociative Disorders (DDs) for DSM-5. The periodic revision of the DSM provides an opportunity to revisit the assumptions underlying specific diagnoses and the empirical support, or lack of it, for the defining diagnostic criteria. This paper reviews clinical, phenomenological, epidemiological, cultural, and neurobiological data related to the DDs in order to generate an up-to-date, evidence-based set of DD diagnoses and diagnostic criteria for DSM-5. First, we review the definitions of dissociation and the differences between the definitions of dissociation and conceptualization of DDs in the DSM-IV-TR and the ICD-10, respectively. Also, we review more general conceptual issues in defining dissociation and dissociative disorders. Based on this review, we propose a revised definition of dissociation for DSM-5 and discuss the implications of this definition for understanding dissociative symptoms and disorders. We make the following recommendations for DSM-5: 1. Depersonalization Disorder (DPD) should include derealization symptoms as well. 2. Dissociative Fugue should become a subtype of Dissociative Amnesia (DA). 3. The diagnostic criteria for DID should be changed to emphasize the disruptive nature of the dissociation and amnesia for everyday as well as traumatic events. The experience of possession should be included in the definition of identity disruption. 4. Dissociative Trance Disorder should be included in the Unspecified Dissociative Disorder (UDD) category. There is a growing body of evidence linking the dissociative disorders to a trauma history, and to specific neural mechanisms. © 2011 Wiley Periodicals, Inc.

Dissociative disorders in DSM-5.

PubMed

Spiegel, David; Loewenstein, Richard J; Lewis-Fernández, Roberto; Sar, Vedat; Simeon, Daphne; Vermetten, Eric; Cardeña, Etzel; Dell, Paul F

2011-09-01

We present recommendations for revision of the diagnostic criteria for the Dissociative Disorders (DDs) for DSM-5. The periodic revision of the DSM provides an opportunity to revisit the assumptions underlying specific diagnoses and the empirical support, or lack of it, for the defining diagnostic criteria. This paper reviews clinical, phenomenological, epidemiological, cultural, and neurobiological data related to the DDs in order to generate an up-to-date, evidence-based set of DD diagnoses and diagnostic criteria for DSM-5. First, we review the definitions of dissociation and the differences between the definitions of dissociation and conceptualization of DDs in the DSM-IV-TR and the ICD-10, respectively. Also, we review more general conceptual issues in defining dissociation and dissociative disorders. Based on this review, we propose a revised definition of dissociation for DSM-5 and discuss the implications of this definition for understanding dissociative symptoms and disorders. We make the following recommendations for DSM-5: 1. Depersonalization Disorder (DPD) should derealization symptoms as well. 2. Dissociative Fugue should become a subtype of Dissociative Amnesia (DA). 3. The diagnostic criteria for DID should be changed to emphasize the disruptive nature of the dissociation and amnesia for everyday as well as traumatic events. The experience of possession should be included in the definition of identity disruption. 4. Should Dissociative Trance Disorder should be included in the Unspecified Dissociative Disorder (UDD) category. There is a growing body of evidence linking the dissociative disorders to a trauma history, and to specific neural mechanisms. © 2011 Wiley-Liss, Inc.

Dissociation mediates the association between intimate partner violence and posttraumatic stress among treatment-seeking incarcerated women.

PubMed

DeCou, Christopher R; Lynch, Shannon M; Cole, Trevor T; Kaplan, Stephanie P

2016-01-01

Women in prison experience high rates of interpersonal trauma as well as elevated rates of posttraumatic stress disorder (PTSD) relative to women in the general population. The present study examined the relationship between recent intimate partner violence (IPV), additional forms of lifetime trauma exposure, trait dissociation, and posttraumatic stress among a sample of incarcerated female survivors of IPV. Participants were 186 treatment-seeking incarcerated women who reported experiences of IPV in the year prior to incarceration. Participants completed self-report measures of IPV, nonpartner-perpetrated lifetime trauma exposure, trait dissociation, and PTSD symptomatology. Associations among study variables were evaluated using sequential multiple regression. Participants reported experiencing several forms of interpersonal trauma. More than half of respondents (i.e., 53%) fell beyond a conservative cutoff score on the PTSD Checklist-Civilian Version, indicating clinically significant symptoms of PTSD. Trait dissociation partially mediated the association between IPV and PTSD symptoms above and beyond history of nonpartner-perpetrated violence. Trait dissociation emerged as the strongest independent predictor of PTSD symptoms and explained approximately 15% of the variance in PTSD symptoms. This finding highlights the need for additional research concerning dissociation among women in prison and warrants consideration in future research and intervention efforts focused on trauma recovery among incarcerated women.

A single sample study of dissociation between expressed and experienced pleasure by gender in mild depression.

PubMed

Brown, S L

Thirty male and thirty female adult subjects were divided equally into three groups on the basis of the Zung Self-Rating Depression Scale; mildly depressed (50-63), normal (40-49), and "low normal" (20-39). Observer ratings of positive affect were made during a one and one-half hour laboratory experiment, and self-ratings of pleasurable experience were collected at the end of the experiment. Results showed no significant differences between groups for self-report of experienced pleasure. However, a significant difference between groups was found for observer ratings of positive affect, with the mildly depressed and "low normal" subjects showing a shorter duration and a lower degree of positive affect than the normals. These results partially replicate and extended previous work. Implications for theory, research, and psychotherapy are discussed.

[Dissociative disorders: from Janet to DSM-IV].

PubMed

Nakatani, Y

2000-01-01

I reviewed the literature on dissociation and dissociative disorders from Pierre Janet to DSM-IV, and examined the current trends in research. Janet's theory on hysteria is multifaceted, and is based on three psychological models. Based on a hierarchical model, Janet related hysteric symptoms to the activities within the lower strata of mental hierarchy (automatisms psychologiques), which were demonstrably shown in somnambulism. A second model was based on the concept of a psychological system, which was hypothetically composed of ideas, images, feelings, sensations, and movements. According to this model, dissociation of psychological functions was fundamental to the mechanism of hysteria: loss of integration was thought to engender fixed ideas (ideas fixes) and to lead to the development of a system totally isolated from the whole personality system. Janet also attempted to explain various mental disorders using an economic model. He referred to a loss of equilibration between psychological force and psychological tension. Thus, an unexpected emotional experience was conceived to cause a consumption of reserved psychological force, which was in turn followed by exhaustion associated with hysteric symptoms. Whereas most current researchers regard Janet as the first to study psychological trauma as a principal cause of dissociation, I feel it is important to note that he also emphasized the role of stigmata, i.e., permanent traits of hysteric patients, which were represented as a suggestibility and a tendency toward a narrowing of the consciousness field. Discussion about dissociation and its relation to trauma all but disappeared after Janet. However, during the Second World War and post-war period, some psychiatrists began to pay attention to two emerging phenomena: a high incidence of dissociative symptoms such as fugue and amnesia among combatants, and traumatic neurosis frequently observed among ex-inmates of concentration camps. In the 1970s, interest in dissociation and trauma was revived in different areas: the feminism movement was linked with concerns about child sexual abuse, public curiosity about multiple personalities was heightened by novels and movies, and recognition of posttraumatic stress disorder (PTSD) among Vietnam War veterans. In 1980, dissociative disorders were finally adopted as a diagnostic category in the official nomenclature of DSM-III. Although current research on dissociation is being carried out in various fields, two basic assumptions, reflected in the definition of DSM-IV, can be made. One is the "trauma-genic hypothesis," and the other is the great importance attached to multiple personality disorder (MPD). According to the predominantly held view, dissociation represents a reaction to early traumatic experience, especially sexual and physical abuse in childhood. In contrast, some authors argue that the causality of childhood traumatic experience has not been empirically confirmed, and other factors such as the influence of the environment and the predisposition of patients should be taken into consideration. MPD, which was originally described as an unusual phenomenon in classical literature, is currently thought to be a common type of dissociation. However, the reported rapid increase in the number of MPD patients in North America may be partially due to over-diagnosis and inclusion of iatrogenic cases. Significance is also given to MPD in respect to classification of dissociative phenomena. According to the widely held scheme of a "dissociative continuum," which ranges from normal experiences such as daydreams to pathological states, MPD is placed at the extreme end of the continuum. Furthermore, most researchers tend to classify MPD as the severest dissociative disorder due to chronic trauma. On this point, there seems to be confusion about "extremity" and "severity" of MPD. I conclude that the trauma-genic hypothesis of dissociation and the overemphasis placed on MPD should be reexamin

Electromagnetic Dissociation of Uranium in Heavy Ion Collisions at 120 Mev/a

NASA Astrophysics Data System (ADS)

Justice, Marvin Lealon

The heavy-ion induced electromagnetic dissociation (EMD) of a 120 MeV/A ^{238}U beam incident on five targets (^9Be, ^{27}Al, ^ {nat}Cu, ^{nat} Ag, and ^{nat}U) has been studied experimentally. Electromagnetic dissociation at this beam energy is essentially a two step process involving the excitation of a giant resonance followed by particle decay. At 120 MeV/A there is predicted to be a significant contribution (~25%) of the giant quadrupole resonance to the EMD cross sections. The specific exit channel which was looked at was projectile fission. The two fission fragments were detected in coincidence by an array of solid-state DeltaE-E detectors, allowing the charges of the fragments to be determined to within +/- .5 units. The events were sorted on the basis of the sums of the fragments' charges, acceptance corrections were applied, and total cross sections for the most peripheral events (i.e. those leading to charge sums of approximately 92) were determined. Electromagnetic fission at the beam energy of this experiment always leads to a true charge sum of 92. Due to the imperfect resolution of the detectors, charge sums of 91 and 93 were included in order to account for all of the electromagnetic fission events. The experimentally observed cross sections are due to nuclear interaction processes as well as electromagnetic processes. Under the conditions of this experiment, the cross sections for the beryllium target are almost entirely due to nuclear processes. The nuclear cross sections for the other four targets were determined by extrapolation from the beryllium data using a geometrical scaling model. After subtraction of the nuclear cross sections, the resulting electromagnetic cross sections are compared to theoretical calculations based on the equivalent photon approximation. Systematic uncertainties associated with the normalization of the data make quantitative comparisons with theory difficult, however. The systematic uncertainties are discussed and suggestions for improving the experiment are given.

Nonequilibrium recombination after a curved shock wave

NASA Astrophysics Data System (ADS)

Wen, Chihyung; Hornung, Hans

2010-02-01

The effect of nonequilibrium recombination after a curved two-dimensional shock wave in a hypervelocity dissociating flow of an inviscid Lighthill-Freeman gas is considered. An analytical solution is obtained with the effective shock values derived by Hornung (1976) [5] and the assumption that the flow is ‘quasi-frozen’ after a thin dissociating layer near the shock. The solution gives the expression of dissociation fraction as a function of temperature on a streamline. A rule of thumb can then be provided to check the validity of binary scaling for experimental conditions and a tool to determine the limiting streamline that delineates the validity zone of binary scaling. The effects on the nonequilibrium chemical reaction of the large difference in free stream temperature between free-piston shock tunnel and equivalent flight conditions are discussed. Numerical examples are presented and the results are compared with solutions obtained with two-dimensional Euler equations using the code of Candler (1988) [10].

Exact and conceptual repetition dissociate conceptual memory tests: problems for transfer appropriate processing theory.

PubMed

McDermott, K B; Roediger, H L

1996-03-01

Three experiments examined whether a conceptual implicit memory test (specifically, category instance generation) would exhibit repetition effects similar to those found in free recall. The transfer appropriate processing account of dissociations among memory tests led us to predict that the tests would show parallel effects; this prediction was based upon the theory's assumption that conceptual tests will behave similarly as a function of various independent variables. In Experiment 1, conceptual repetition (i.e., following a target word [e.g., puzzles] with an associate [e.g., jigsaw]) did not enhance priming on the instance generation test relative to the condition of simply presenting the target word once, although this manipulation did affect free recall. In Experiment 2, conceptual repetition was achieved by following a picture with its corresponding word (or vice versa). In this case, there was an effect of conceptual repetition on free recall but no reliable effect on category instance generation or category cued recall. In addition, we obtained a picture superiority effect in free recall but not in category instance generation. In the third experiment, when the same study sequence was used as in Experiment 1, but with instructions that encouraged relational processing, priming on the category instance generation task was enhanced by conceptual repetition. Results demonstrate that conceptual memory tests can be dissociated and present problems for Roediger's (1990) transfer appropriate processing account of dissociations between explicit and implicit tests.

Effects of trauma-related cues on pain processing in posttraumatic stress disorder: an fMRI investigation

PubMed Central

Mickleborough, Marla J.S.; Daniels, Judith K.; Coupland, Nicholas J.; Kao, Raymond; Williamson, Peter C.; Lanius, Ulrich F.; Hegadoren, Kathy; Schore, Allan; Densmore, Maria; Stevens, Todd; Lanius, Ruth A.

2011-01-01

Background Imaging studies of pain processing in primary psychiatric disorders are just emerging. This study explored the neural correlates of stress-induced analgesia in individuals with posttraumatic stress disorder (PTSD). It combined functional magnetic resonance imaging (fMRI) and the traumatic script-driven imagery symptom provocation paradigm to examine the effects of trauma-related cues on pain perception in individuals with PTSD. Methods The study included 17 patients with PTSD and 26 healthy, trauma-exposed controls. Participants received warm (nonpainful) or hot (painful) thermal stimuli after listening to a neutral or a traumatic script while they were undergoing an fMRI scan at a 4.0 T field strength. Results Between-group analyses revealed that after exposure to the traumatic scripts, the blood oxygen level–dependent (BOLD) signal during pain perception was greater in the PTSD group than the control group in the head of the caudate. In the PTSD group, strong positive correlations resulted between BOLD signal and symptom severity in a number of brain regions previously implicated in stress-induced analgesia, such as the thalamus and the head of the caudate nucleus. Trait dissociation as measured by the Dissociative Experiences Scale correlated negatively with the right amygdala and the left putamen. Limitations This study included heterogeneous traumatic experiences, a different proportion of military trauma in the PTSD versus the control group and medicated patients with PTSD. Conclusion These data indicate that in patients with PTSD trauma recall will lead in a state-dependent manner to greater activation in brain regions implicated in stress-induced analgesia. Correlational analyses lend support to cortical hyperinhibition of the amygdala as a function of dissociation. PMID:20964954

Atypical cleavage of protonated N-fatty acyl amino acids derived from aspartic acid evidenced by sequential MS3 experiments.

PubMed

Boukerche, Toufik Taalibi; Alves, Sandra; Le Faouder, Pauline; Warnet, Anna; Bertrand-Michel, Justine; Bouchekara, Mohamed; Belbachir, Mohammed; Tabet, Jean-Claude

2016-12-01

Lipidomics calls for information on detected lipids and conjugates whose structural elucidation by mass spectrometry requires to rationalization of their gas phase dissociations toward collision-induced dissociation (CID) processes. This study focused on activated dissociations of two lipoamino acid (LAA) systems composed of N-palmitoyl acyl coupled with aspartic and glutamic acid mono ethyl esters (as LAA (*D) and LAA (*E) ). Although in MS/MS, their CID spectra show similar trends, e.g., release of water and ethanol, the [(LAA (*D/*E) +H)-C 2 H 5 OH] + product ions dissociate via distinct pathways in sequential MS 3 experiments. The formation of all the product ions is rationalized by charge-promoted cleavages often involving stepwise processes with ion isomerization into ion-dipole prior to dissociation. The latter explains the maleic anhydride or ketene neutral losses from N-palmitoyl acyl aspartate and glutamate anhydride fragment ions, respectively. Consequently, protonated palmitoyl acid amide is generated from LAA (*D), whereas LAA (*E) leads to the [*E+H-H 2 O] + anhydride. The former releases ammonia to provide acylium, which gives the C n H (2n-1) and C n H (2n-3) carbenium series. This should offer structural information, e.g., to locate either unsaturation(s) or alkyl group branching present on the various fatty acyl moieties of lipo-aspartic acid in further studies based on MS n experiments.

Words, Hemispheres, and Dissociable Subsystems: The Effects of Exposure Duration, Case Alternation, Priming, and Continuity of Form on Word Recognition in the Left and Right Visual Fields

ERIC Educational Resources Information Center

Ellis, Andrew W.; Ansorge, Lydia; Lavidor, Michal

2007-01-01

Three experiments explore aspects of the dissociable neural subsystems theory of hemispheric specialisation proposed by Marsolek and colleagues, and in particular a study by [Deason, R. G., & Marsolek, C. J. (2005). A critical boundary to the left-hemisphere advantage in word processing. "Brain and Language," 92, 251-261]. Experiment 1A showed…

Determination of the Acid Dissociation Constant of a Phenolic Acid by High Performance Liquid Chromatography: An Experiment for the Upper Level Analytical Chemistry Laboratory

ERIC Educational Resources Information Center

Raboh, Ghada

2018-01-01

A high performance liquid chromatography (HPLC) experiment for the upper level analytical chemistry laboratory is described. The students consider the effect of mobile-phase composition and pH on the retention times of ionizable compounds in order to determine the acid dissociation constant, K[subscript a], of a phenolic acid. Results are analyzed…

Incidence and Predictors of Acute Psychological Distress and Dissociation after Motor Vehicle Collision: a Cross-Sectional Study

PubMed Central

Lewis, Gemma C.; Platts-Mills, Timothy F.; Liberzon, Israel; Bair, Eric; Swor, Robert; Peak, David; Jones, Jeffrey; Rathlev, Niels; Lee, David; Domeier, Robert; Hendry, Phyllis; McLean, Samuel A.

2014-01-01

Objective The authors examined the incidence and predictors of peritraumatic distress and dissociation after one of the most common forms of civilian trauma exposure: motor vehicle collision (MVC). Methods In this study, patients presenting to the emergency department after MVC who were without serious injury and discharged to home after evaluation (n = 935) completed an emergency department interview evaluating sociodemographic, collision-related, and psychological characteristics. Results The incidence and predictors of distress (Peritraumatic Distress Inventory score ≥ 23) and dissociation (Michigan Critical Events Perception Scale score >3) were assessed. Distress was present in 355 of 935 patients (38%) and dissociation was present in 260 of 942 patients (28%). These outcomes showed only moderate correlation (r = 0.45), and had both shared and distinct predictors. Female gender, anxiety symptoms prior to MVC, and vehicle damage severity predicted both distress and dissociation. Higher socioeconomic status (higher education, higher income, full time employment) had a protective effect against distress but not dissociative symptoms. Better physical health and worse overall mental health were associated with increased risk of dissociation, but not distress. Distress but not dissociation was associated with lower patient confidence in recovery and a longer expected duration of recovery. Conclusion There are unique predictors of peritraumatic distress and dissociation. Further work is needed to better understand the neurobiology of peritraumatic distress and dissociation, and the influence of these peritraumatic outcomes on persistent psychological sequelae. PMID:24983475

[Be in role. Examination of dissociative experiences of theatrical actors].

PubMed

Docsa, Viktória Pálma; Szemán-Nagy, Anita

2012-01-01

In spite of the fact that acting makes great demands on the personality, there is lack of research dealing with the psychological status of actors. Resulted from their profession actors often experience dissociation, since absorption and changing of their identity is a routine task for them. They are acting on the stage, and they are acting in private. 36 theatrical actors completed the DISQ-H version of the Dissociation Questionnaire measuring four subscales: Identity Confusion, Amnesia, Loss of Control and Absorption. In order to understand their experiences deeper, nine actors were interviewed. The sample consisted of 21 men and 15 women and their ages ranged from 23 to 60. Higher ages implied longer career as an actor, thus the youngest subject had been working for 2 years, while the oldest one had been working for 39 years. DISQ-H total score results of the actors were significantly higher compared to the Hungarian standard scores. As we expected, the two non-pathological subscales (Loss of Control and Absorption) showed significant differences compared to the standard scores of the subscales. In the case of Identity Confusion subscale we found no significant differences, however the results indicate that the tendency observed emphasizes the importance of further research of this phenomenon. To sum up, dissociative experiences proved to be important elements of acting.

Sleep loss increases dissociation and affects memory for emotional stimuli.

PubMed

van Heugten-van der Kloet, Dalena; Giesbrecht, Timo; Merckelbach, Harald

2015-06-01

Because of their dreamlike character, authors have speculated about the role that the sleep-wake cycle plays in dissociative symptoms. We investigated whether sleep loss fuels dissociative symptoms and undermines cognitive efficiency, particularly memory functioning. Fifty-six healthy undergraduate students were randomly assigned to an experimental group (n = 28) and a control group (n = 28). The experimental group was deprived of sleep for 36 h in a sleep laboratory; the control group had a regular night of sleep. Sleepiness, mood, and dissociative symptoms were assessed 6 times in the experimental group (control group: 4 times). Several cognitive tasks were administered. Sleep deprivation led to an increase in dissociative symptoms, which was mediated by levels of general distress. Feelings of sleepiness preceded an increase of dissociative symptoms and deterioration of mood. Finally, sleep loss also undermined memory of emotional material, especially in highly dissociative individuals. Limitations included moderate reliability of the mood scale, limited generalizability due to student sample, and a relatively short period of intensive sleep deprivation rather than lengthy but intermittent sleep loss, representative of a clinical population. We found that sleep deprivation had significant effects on dissociation, sleepiness, and mood. Specifically, sleepiness and dissociation increased during the night, while mood deteriorated. Our findings stress the importance of sleep deficiencies in the development of dissociative symptoms. They support the view that sleep disruptions fuel distress, but also degrade memory and attentional control. It is against this background that dissociative symptoms may arise. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dissociative Photoionization of the Elusive Vinoxy Radical.

PubMed

Adams, Jonathan D; Scrape, Preston G; Lee, Shih-Huang; Butler, Laurie J

2017-08-24

These experiments report the dissociative photoionization of vinoxy radicals to m/z = 15 and 29. In a crossed laser-molecular beam scattering apparatus, we induce C-Cl bond fission in 2-chloroacetaldehyde by photoexcitation at 157 nm. Our velocity measurements, combined with conservation of angular momentum, show that 21% of the C-Cl photofission events form vinoxy radicals that are stable to subsequent dissociation to CH 3 + CO or H + ketene. Photoionization of these stable vinoxy radicals, identified by their velocities, which are momentum-matched with the higher-kinetic-energy Cl atom photofragments, shows that the vinoxy radicals dissociatively photoionize to give signal at m/z = 15 and 29. We calibrated the partial photoionization cross section of vinoxy to CH 3 + relative to the bandwidth-averaged photoionization cross section of the Cl atom at 13.68 eV to put the partial photoionization cross sections on an absolute scale. The resulting bandwidth-averaged partial cross sections are 0.63 and 1.3 Mb at 10.5 and 11.44 eV, respectively. These values are consistent with the upper limit to the cross section estimated from a study by Savee et al. on the O( 3 P) + propene bimolecular reaction. We note that the uncertainty in these values is primarily dependent on the signal attributed to C-Cl primary photofission in the m/z = 35 (Cl + ) time-of-flight data. While the value is a rough estimate, the bandwidth-averaged partial photoionization cross section of vinoxy to HCO + calculated from the signal at m/z = 29 at 11.53 eV is approximately half that of vinoxy to CH 3 + . We also present critical points on the potential energy surface of the vinoxy cation calculated at the G4//B3LYP/6-311++G(3df,2p) level of theory to support the observation of dissociative ionization of vinoxy to both CH 3 + and HCO + .

Learning and liking an artificial musical system: Effects of set size and repeated exposure

PubMed Central

Loui, Psyche; Wessel, David

2009-01-01

We report an investigation of humans' musical learning ability using a novel musical system. We designed an artificial musical system based on the Bohlen-Pierce scale, a scale very different from Western music. Melodies were composed from chord progressions in the new scale by applying the rules of a finite-state grammar. After exposing participants to sets of melodies, we conducted listening tests to assess learning, including recognition tests, generalization tests, and subjective preference ratings. In Experiment 1, participants were presented with 15 melodies 27 times each. Forced choice results showed that participants were able to recognize previously encountered melodies and generalize their knowledge to new melodies, suggesting internalization of the musical grammar. Preference ratings showed no differentiation among familiar, new, and ungrammatical melodies. In Experiment 2, participants were given 10 melodies 40 times each. Results showed superior recognition but unsuccessful generalization. Additionally, preference ratings were significantly higher for familiar melodies. Results from the two experiments suggest that humans can internalize the grammatical structure of a new musical system following exposure to a sufficiently large set size of melodies, but musical preference results from repeated exposure to a small number of items. This dissociation between grammar learning and preference will be further discussed. PMID:20151034

Learning and liking an artificial musical system: Effects of set size and repeated exposure.

PubMed

Loui, Psyche; Wessel, David

2008-10-01

We report an investigation of humans' musical learning ability using a novel musical system. We designed an artificial musical system based on the Bohlen-Pierce scale, a scale very different from Western music. Melodies were composed from chord progressions in the new scale by applying the rules of a finite-state grammar. After exposing participants to sets of melodies, we conducted listening tests to assess learning, including recognition tests, generalization tests, and subjective preference ratings. In Experiment 1, participants were presented with 15 melodies 27 times each. Forced choice results showed that participants were able to recognize previously encountered melodies and generalize their knowledge to new melodies, suggesting internalization of the musical grammar.Preference ratings showed no differentiation among familiar, new, and ungrammatical melodies. In Experiment 2, participants were given 10 melodies 40 times each. Results showed superior recognition but unsuccessful generalization. Additionally, preference ratings were significantly higher for familiar melodies. Results from the two experiments suggest that humans can internalize the grammatical structure of a new musical system following exposure to a sufficiently large set size of melodies, but musical preference results from repeated exposure to a small number of items. This dissociation between grammar learning and preference will be further discussed.

Enhanced accessibility of ignored neutral and negative items in nonclinical dissociative individuals.

PubMed

Chiu, Chui-De

2018-01-01

While clinical studies showed paradoxical memory phenomena, including the intrusion and amnesia of stressful experiences that are features of dissociation, the results of laboratory studies on dissociative individuals' forgetting of experimental stimuli through cognitive control varied. Some studies demonstrated ineffective inhibition, and others found that dissociative individuals could remember fewer trauma words in a divided-attention context. Dissociative individuals may utilize superior cognitive disengagement to forget the representations. This hypothesis was tested in nonclinical individuals with high, medium, and low dissociation proneness. In the study phase, the participants learned several lists of experimental words and kept updating working memory by remembering the last four items on a list (target) and ignoring those non-target items. A recognition test was then conducted. The high dissociation group performed better on updating working memory. However, the accessibility of the representations of neutral and negative non-target items was elevated. Dissociative individuals disengaged attention effectively from items they intended to ignore, and the representations of the ignored items were more accessible when cues were available. Copyright © 2017 Elsevier Inc. All rights reserved.

Dissociative symptoms and sleep parameters--an all-night polysomnography study in patients with insomnia.

PubMed

Van Der Kloet, Dalena; Giesbrecht, Timo; Franck, Erik; Van Gastel, Ann; De Volder, Ilse; Van Den Eede, Filip; Verschuere, Bruno; Merckelbach, Harald

2013-08-01

Dissociative disorders encompass a range of symptoms varying from severe absent-mindedness and memory problems to confusion about one's own identity. Recent studies suggest that these symptoms may be the by-products of a labile sleep-wake cycle. In the current study, we explored this issue in patients suffering from insomnia (N=46). We investigated whether these patients have raised levels of dissociative symptoms and whether these are related to objective sleep parameters. Patients stayed for at least one night in a specialized sleep clinic, while sleep EEG data were obtained. In addition, they completed self-report measures on dissociative symptoms, psychological problems, and sleep characteristics. Dissociative symptom levels were elevated in patients suffering from insomnia, and were correlated with unusual sleep experiences and poor sleep quality. Longer REM sleep periods and less time spent awake during the night were predictive of dissociation. This is the first study to show that insomnia patients have raised dissociative symptom levels and that their dissociative symptoms are related to objective EEG parameters. These findings are important because they may inspire sleep-related treatment methods for dissociative disorders. Copyright © 2013 Elsevier Inc. All rights reserved.

Surface-induced dissociation: a unique tool for studying energetics and kinetics of the gas-phase fragmentation of large ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laskin, Julia

2015-01-01

Surface-induced dissociation (SID) is valuable tool for investigating activation and dissociation of large ions in tandem mass spectrometry. This account summarizes key findings from studies of the energetics and mechanisms of complex ion dissociation, in which SID experiments were combined with Rice-Ramsperger-Kassel-Marcus (RRKM) modeling of the experimental data. These studies used time- and collision-energy-resolved SID experiments and SID combined with resonant ejection of selected fragment ions on a specially designed Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS). Fast ion activation by collision with a surface combined with the long and variable timescale of a FT-ICR MS is perfectlymore » suited for studying the energetics and dynamics of complex ion dissociation in the gas phase. Modeling of time- and collision-energy-resolved SID enables accurate determination of energy and entropy effects in the dissociation process. It has been demonstrated that entropy effects play an important role in determining the dissociation rates of both covalent and non-covalent bonds in large gaseous ions. SID studies have provided important insights on the competition between charge-directed and charge-remote fragmentation in even-electron peptide ions and the role of charge and radical site on the energetics of the dissociation of odd-electron peptide ions. Furthermore, this work examined factors that affect the strength of non-covalent binding, as well as the competition between covalent and non-covalent bond cleavages and between proton and electron transfer in model systems. Finally, SID studies have been used to understand the factors affecting nucleation and growth of clusters in solution and the gas phase.« less

Controllable dissociations of PH3 molecules on Si(001)

NASA Astrophysics Data System (ADS)

Liu, Qin; Lei, Yanhua; Shao, Xiji; Ming, Fangfei; Xu, Hu; Wang, Kedong; Xiao, Xudong

2016-04-01

We demonstrate for the first time to our knowledge that controllable dissociation of PH3 adsorption products PH x (x = 2, 1) can be realized by STM (scanning tunneling microscope) manipulation techniques at room temperature. Five dissociative products and their geometric structures are identified via combining STM experiments and first-principle calculations and simulations. In total we realize nine kinds of controllable dissociations by applying a voltage pulse among the PH3-related structures on Si(001). The dissociation rates of the five most common reactions are measured by the I-t spectrum method as a function of voltage. The suddenly increased dissociation rate at 3.3 V indicates a transition from multivibrational excitation to single-step excitation induced by inelastic tunneling electrons. Our studies prove that selectively breaking the chemical bonds of a single molecule on semiconductor surface by STM manipulation technique is feasible.

The Dual Role of Disorder on the Dissociation of Interfacial Charge Transfer Excitons

NASA Astrophysics Data System (ADS)

Shi, Liang; Lee, Chee-Kong; Willard, Adam

In organic-based photovoltaics (OPV), dissociation of neutral photo-excitations (i.e., Frenkel excitons) into free charge carriers requires the excitons to overcome binding energy that can significantly exceed thermal energies. The inability of bound charges to overcome this large binding energy has been implicated as a primary source of efficiency loss in OPVs. Despite the potential impact on the performance of organic solar cells much remains to be understood about the microscopic mechanism of exciton dissociation in OPV materials. Here we explore the role of static molecular disorder in mediating this charge dissociation process. Using a simple lattice model of exciton dynamics we demonstrate that random spatial variations in the energetic landscape can mitigate the effects of the exciton binding energy by lowering the free energy barrier. By considering the competition between this thermodynamic effect and the disorder-induced slowing of dissociation kinetics we demonstrate that exciton dissociation yields are expected to depend non-monotonically on the degree of static disorder. We conclude that a certain amount of molecular-scale disorder is desirable in order to optimize the performance of organic photovoltaic materials.

Probing the energetics of dissociation of carbonic anhydrase-ligand complexes in the gas phase.

PubMed Central

Gao, J; Wu, Q; Carbeck, J; Lei, Q P; Smith, R D; Whitesides, G M

1999-01-01

This paper describes the use of electrospray ionization-Fourier transform ion cyclotron mass spectrometry (ESI-FTICR-MS) to study the relative stabilities of noncovalent complexes of carbonic anhydrase II (CAII, EC 4.2.1.1) and benzenesulfonamide inhibitors in the gas phase. Sustained off-resonance irradiation collision-induced dissociation (SORI-CID) was used to determine the energetics of dissociation of these CAII-sulfonamide complexes in the gas phase. When two molecules of a benzenesulfonamide (1) were bound simultaneously to one molecule of CAII, one of them was found to exhibit significantly weaker binding (DeltaE50 = 0.4 V, where E50 is defined as the amplitude of sustained off-resonance irradiation when 50% of the protein-ligand complexes are dissociated). In solution, the benzenesulfonamide group coordinates as an anion to a Zn(II) ion bound at the active site of the enzyme. The gas phase stability of the complex with the weakly bound inhibitor was the same as that of the inhibitor complexed with apoCAII (i.e., CAII with the Zn(II) ion removed from the binding site). These results indicate that specific interactions between the sulfonamide group on the inhibitor and the Zn(II) ion on CAII were preserved in the gas phase. Experiments also showed a higher gas phase stability for the complex of para-NO2-benzenesulfonamide-CAII than that for ortho-NO2-benzenesulfonamide-CAII complex. This result further suggests that steric interactions of the inhibitors with the binding pocket of CAII parallel those in solution. Overall, these results are consistent with the hypothesis that CAII retains, at least partially, the structure of its binding pocket in the gas phase on the time scale (seconds to minutes) of the ESI-FTICR measurements. PMID:10354450

Dissociable meta-analytic brain networks contribute to coordinated emotional processing.

PubMed

Riedel, Michael C; Yanes, Julio A; Ray, Kimberly L; Eickhoff, Simon B; Fox, Peter T; Sutherland, Matthew T; Laird, Angela R

2018-06-01

Meta-analytic techniques for mining the neuroimaging literature continue to exert an impact on our conceptualization of functional brain networks contributing to human emotion and cognition. Traditional theories regarding the neurobiological substrates contributing to affective processing are shifting from regional- towards more network-based heuristic frameworks. To elucidate differential brain network involvement linked to distinct aspects of emotion processing, we applied an emergent meta-analytic clustering approach to the extensive body of affective neuroimaging results archived in the BrainMap database. Specifically, we performed hierarchical clustering on the modeled activation maps from 1,747 experiments in the affective processing domain, resulting in five meta-analytic groupings of experiments demonstrating whole-brain recruitment. Behavioral inference analyses conducted for each of these groupings suggested dissociable networks supporting: (1) visual perception within primary and associative visual cortices, (2) auditory perception within primary auditory cortices, (3) attention to emotionally salient information within insular, anterior cingulate, and subcortical regions, (4) appraisal and prediction of emotional events within medial prefrontal and posterior cingulate cortices, and (5) induction of emotional responses within amygdala and fusiform gyri. These meta-analytic outcomes are consistent with a contemporary psychological model of affective processing in which emotionally salient information from perceived stimuli are integrated with previous experiences to engender a subjective affective response. This study highlights the utility of using emergent meta-analytic methods to inform and extend psychological theories and suggests that emotions are manifest as the eventual consequence of interactions between large-scale brain networks. © 2018 Wiley Periodicals, Inc.

An analysis of combustion studies in shock expansion tunnels and reflected shock tunnels

NASA Technical Reports Server (NTRS)

Jachimowski, Casimir J.

1992-01-01

The effect of initial nonequilibrium dissociated air constituents on the combustion of hydrogen in high-speed flows for a simulated Mach 17 flight condition was investigated by analyzing the results of comparative combustion experiments performed in a reflected shock tunnel test gas and in a shock expansion tunnel test gas. The results were analyzed and interpreted with a one-dimensional quasi-three-stream combustor code that includes finite rate combustion chemistry. The results of this study indicate that the combustion process is kinetically controlled in the experiments in both tunnels and the presence of the nonequilibrium partially dissociated oxygen in the reflected shock tunnel enhances the combustion. Methods of compensating for the effect of dissociated oxygen are discussed.

Cell membrane antigen-antibody complex dissociation by the widely used glycine-HCL method: an unreliable procedure for studying antibody internalization.

PubMed

Tsaltas, G; Ford, C H

1993-02-01

Methods following the process of binding and internalization of antibodies to cell surface antigens have often employed low pH isoosmolar buffers in order to dissociate surface antigen-antibody complexes. One of the most widely used buffers is a 0.05 M glycine-HCL buffer pH 2.8. Since the efficacy of action of this buffer was critical to a series of internalization experiments employing monoclonal antibodies (Mabs) to carcinoembryonic antigen (CEA) expressing cancer cell lines in this laboratory, we tested its performance in a number of different assays. Our results indicate that this buffer only partially dissociates antigen-antibody bonds and therefore can introduce major inaccuracies in internalization experiments.

Leveraging Electron Transfer Dissociation for Site Selective Radical Generation: Applications for Peptide Epimer Analysis

NASA Astrophysics Data System (ADS)

Lyon, Yana A.; Beran, Gregory; Julian, Ryan R.

2017-07-01

Traditional electron-transfer dissociation (ETD) experiments operate through a complex combination of hydrogen abundant and hydrogen deficient fragmentation pathways, yielding c and z ions, side-chain losses, and disulfide bond scission. Herein, a novel dissociation pathway is reported, yielding homolytic cleavage of carbon-iodine bonds via electronic excitation. This observation is very similar to photodissociation experiments where homolytic cleavage of carbon-iodine bonds has been utilized previously, but ETD activation can be performed without addition of a laser to the mass spectrometer. Both loss of iodine and loss of hydrogen iodide are observed, with the abundance of the latter product being greatly enhanced for some peptides after additional collisional activation. These observations suggest a novel ETD fragmentation pathway involving temporary storage of the electron in a charge-reduced arginine side chain. Subsequent collisional activation of the peptide radical produced by loss of HI yields spectra dominated by radical-directed dissociation, which can be usefully employed for identification of peptide isomers, including epimers.

Engendered Responses to, and Interventions for, Shame in Dissociative Disorders: A Survey and Experimental Investigation.

PubMed

Dorahy, Martin J; Gorgas, Julia; Seager, Lenaire; Middleton, Warwick

2017-11-01

This study examined shame and responses to it in adult dissociative disorder (DD; n = 24) and comparison psychiatric (n = 14) samples. To investigate how helpful different therapeutic responses are after shame disclosures in therapy, participants heard two vignettes from "mock" patients disclosing a) shame and b) surprise. Participants rated the helpfulness of five potential responses. Interventions covered withdrawing from the affect (withdrawal focused) to feeling it (feeling focused), with other interventions on cognitions (cognitive focused), management strategies (management focused), and previous experiences (history focused). The DD sample reported higher characterological and bodily shame, and more shame avoidance and withdrawal. There was no difference across groups for intervention ratings. For shame, interventions focused on feelings, cognitions, or previous shame experiences were deemed most helpful, but this was qualified by experiencing dissociation while hearing the script, where the history intervention was reported less helpful. Exposure to shame while monitoring dissociation should accompany therapy for DDs.

Acute psychoactive effects of intravenous ketamine during treatment of mood disorders: Analysis of the Clinician Administered Dissociative State Scale.

PubMed

van Schalkwyk, Gerrit I; Wilkinson, Samuel T; Davidson, Larry; Silverman, Wendy K; Sanacora, Gerard

2018-02-01

Ketamine has rapid-acting antidepressant effects. Frequently, ketamine administration also causes acute psychoactive effects - in trials, these effects are commonly measured using the Clinician Administered Dissociative State Scale (CADSS). However, the CADSS was not designed for this specific purpose, having been validated in other clinical contexts, and anecdotally does not appear to fully capture ketamine's acute psychoactive effects. Data were obtained from 110 individuals with mood disorders (predominantly major depressive disorder) who underwent intravenous ketamine infusion. An exploratory factor analysis (EFA) was performed on the CADSS, along with assessment of internal consistency. Qualitative methods were used to conduct in-depth interviews with a subset of these participants to identify key features of the acute ketamine experience, including aspects that may not be captured by the CADSS. The mean total score of the CADSS was low at 7.7 (SD 9.2). Analysis of internal consistency showed a Cronbach's alpha of 0.74. Five CADSS items had low correlations with the total score. EFA lead to a one-factor solution containing 16 items. Five of the six highest loading items involved perceptual disturbances, either of time or sensation. Qualitative analyses of 10 patient narratives revealed two phenomena not captured on the CADSS: disinhibition and a sense of peace. This study was by limited by the absence of other ratings of the participants' experience. Findings suggest that the CADSS partially captures the acute effects of ketamine administration. Further research may seek to validate a revised version of the CADSS that more accurately measures these effects. Copyright © 2017 Elsevier B.V. All rights reserved.

Dissociative amnesia in dissociative disorders and borderline personality disorder: self-rating assessment in a college population.

PubMed

Sar, Vedat; Alioğlu, Firdevs; Akyuz, Gamze; Karabulut, Sercan

2014-01-01

Dissociative amnesia (DA) among subjects with a dissociative disorder and/or borderline personality disorder (BPD) recruited from a nonclinical population was examined. The Steinberg Dissociative Amnesia Questionnaire (SDAQ), the Childhood Trauma Questionnaire, and the self-report screening tool of the BPD section of the Structured Clinical Interview for DSM-IV(SCID-BPD) were administered to 1,301 college students. A total of 80 participants who were diagnosed with BPD according to the clinician-administered SCID-BPD and 111 nonborderline controls were evaluated using the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D) by a psychiatrist blind to diagnosis and scale scores. Internal consistency analyses and test-retest evaluations suggested that the SDAQ is a reliable instrument for the population studied. Of the participants, 20.6% reported an SDAQ score of 20 or above and impairment by DA. Those who had both dissociative disorder and BPD (n = 78) had the highest SDAQ scores. Both disorders had significant effects on the SCID-D total and amnesia scores in the variance analysis. On SDAQ scores, however, only BPD had this effect. There was a significant interaction between the 2 disorders for the SCID-D total but not for the SDAQ or SCID-D amnesia scores. BPD represented the severity of dissociation and childhood trauma in this study group. However, in contrast to the dissociative disorders, BPD was characterized by better awareness of DA in self-report. The discrepancies between self-report and clinical interview associated with BPD and dissociative disorders are discussed in the context of betrayal theory (J. J. Freyd, 1994) of BPD and perceptual theory (D. B. Beere, 2009) of dissociative disorders.

Not all order memory is equal: Test demands reveal dissociations in memory for sequence information.

PubMed

Jonker, Tanya R; MacLeod, Colin M

2017-02-01

Remembering the order of a sequence of events is a fundamental feature of episodic memory. Indeed, a number of formal models represent temporal context as part of the memory system, and memory for order has been researched extensively. Yet, the nature of the code(s) underlying sequence memory is still relatively unknown. Across 4 experiments that manipulated encoding task, we found evidence for 3 dissociable facets of order memory. Experiment 1 introduced a test requiring a judgment of which of 2 alternatives had immediately followed a word during encoding. This measure revealed better retention of interitem associations following relational encoding (silent reading) than relatively item-specific encoding (judging referent size), a pattern consistent with that observed in previous research using order reconstruction tests. In sharp contrast, Experiment 2 demonstrated the reverse pattern: Memory for the studied order of 2 sequentially presented items was actually better following item-specific encoding than following relational encoding. Experiment 3 reproduced this dissociation in a single experiment using both tests. Experiment 4 extended these findings by further dissociating the roles of relational encoding and item strength in the 2 tests. Taken together, these results indicate that memory for event sequence is influenced by (a) interitem associations, (b) the emphasized directionality of an association, and (c) an item's strength independent of other items. Memory for order is more complicated than has been portrayed in theories of memory and its nuances should be carefully considered when designing tests and models of temporal and relational memory. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Body-part specific interactions of action verb processing with motor behaviour.

PubMed

Klepp, Anne; Niccolai, Valentina; Sieksmeyer, Jan; Arnzen, Stephanie; Indefrey, Peter; Schnitzler, Alfons; Biermann-Ruben, Katja

2017-06-15

The interaction of action-related language processing with actual movement is an indicator of the functional role of motor cortical involvement in language understanding. This paper describes two experiments using single action verb stimuli. Motor responses were performed with the hand or the foot. To test the double dissociation of language-motor facilitation effects within subjects, Experiments 1 and 2 used a priming procedure where both hand and foot reactions had to be performed in response to different geometrical shapes, which were preceded by action verbs. In Experiment 1, the semantics of the verbs could be ignored whereas Experiment 2 included semantic decisions. Only Experiment 2 revealed a clear double dissociation in reaction times: reactions were facilitated when preceded by verbs describing actions with the matching effector. In Experiment 1, by contrast, there was an interaction between verb-response congruence and a semantic variable related to motor features of the verbs. Thus, the double dissociation paradigm of semantic motor priming was effective, corroborating the role of the motor system in action-related language processing. Importantly, this effect was body part specific. Copyright © 2017 Elsevier B.V. All rights reserved.

Body awareness and mindfulness: validation of the Spanish version of the Scale of Body Connection.

PubMed

del C Quezada-Berumen, Lucía; González-Ramírez, Mónica T; Cebolla, Ausias; Soler, Joaquim; Garcia-Campayo, Javier

2014-01-01

To assess the psychometric properties and the factor structure of the Spanish version of the Scale of Body Connection (SBC) in a community population of meditators and non-meditators and to investigate the relationships among mindfulness, body awareness and body dissociation. Design. Validation study. Sampling. An internet-based commercial system was used to recruit the sample. Instruments. In addition to the SBC, the Five Facet Mindfulness Questionnaire (FFMQ) and the Depression, Anxiety, and Stress Scale (DASS-21) were administered. A sample of 578 subjects responded to all of the items in the protocol. A total of 55.2% of respondents had some previous experience with meditation. A Scree plot showed a two-factor solution involving the Body Awareness (BA) and Body Dissociation (BD) subscales. This study differed from the original validation study in the lack of independence of the subscales; they were correlated in the present study (r=-.11). Internal consistency for BA was α: .86, and for BD, the α was .62. Test-retest reliability was assessed in a subsample (N=67) and was r=.679 for BA and r=.765 for BD. Hierarchical multiple regression analyses showed that mindfulness practice and the FFMQ factors of Observing and Describing were positive predictors of BA. Describing, Acting with awareness and Non-judging negatively predicted BD, and Observing positively predicted BD. The study confirms the adequacy of the psychometric properties of the Spanish version of the SBC for use in community samples. The relationship between SBC and mindfulness is discussed in light of previous research.

Negative words enhance recognition in nonclinical high dissociators: An fMRI study.

PubMed

de Ruiter, Michiel B; Veltman, Dick J; Phaf, R Hans; van Dyck, Richard

2007-08-01

Memory encoding and retrieval were studied in a nonclinical sample of participants that differed in the amount of reported dissociative experiences (trait dissociation). Behavioral as well as functional imaging (fMRI) indices were used as convergent measures of memory functioning. In a deep vs. shallow encoding paradigm, the influence of dissociative style on elaborative and avoidant encoding was studied, respectively. Furthermore, affectively neutral and negative words were presented, to test whether the effects of dissociative tendencies on memory functioning depended on the affective valence of the stimulus material. Results showed that (a) deep encoding of negative vs. neutral stimuli was associated with higher levels of semantic elaboration in high than in low dissociators, as indicated by increased levels of activity in hippocampus and prefrontal cortex during encoding and higher memory performance during recognition, (b) high dissociators were generally characterized by higher levels of conscious recollection as indicated by increased activity of the hippocampus and posterior parietal areas during recognition, (c) nonclinical high dissociators were not characterized by an avoidant encoding style. These results support the notion that trait dissociation in healthy individuals is associated with high levels of elaborative encoding, resulting in high levels of conscious recollection. These abilities, in addition, seem to depend on the salience of the presented stimulus material.

Multiscale Investigations of the Early Stage Oxidation on Cu Surfaces

NASA Astrophysics Data System (ADS)

Zhu, Qing; Xiao, Penghao; Lian, Xin; Yang, Shen-Che; Henkelman, Grame; Saidi, Wissam; Yang, Judith; University of Pittsburgh Team; University of Texas at Austin Team

Previous in situ TEM experiments have shown that the oxidation of the three low index Cu surfaces (100), (110) and (111) exhibit different oxide nucleation rates, and the resulting oxides have 3-dimensional (3D) island shapes or 2D rafts under different conditions. In order to better understand these results, we have investigated the early stages of Cu oxidation using a multiscale computational approach that employs density functional theory (DFT), reactive force field (ReaxFF), and kinetic Mote Carlo (KMC). With DFT calculation, we have compared O2 dissociation barriers on Cu (100), (110) and (111) surfaces at high oxygen coverage to evaluate the kinetic barrier of sublayer oxidization. We found that O2 dissociation barriers on Cu(111) surface are all lower than those on (110) and (100) surfaces. This trend agrees with experimental observations that (111) surface is easier to oxidize. These DFT calculated energy barriers are then incorporated into KMC simulations. The large scale ReaxFF molecular dynamics and KMC simulations detail the oxidation dynamics of the different Cu surfaces, and show the formation of various oxide morphologies that are consistent with experimental observations.

Cognitive behavioral hypnotherapy for dissociative disorders.

PubMed

Fine, Catherine G

2012-04-01

Dissociative disorders (DD) prevail as sequelae to overwhelming experiences in childhood. These readily formed post-traumatic responses and trance states develop in high hypnotizable subjects whose dysregulations become organized into ego states. A cognitive behavioral hypnotherapeutic treatment model will effectively contain, explore, metabolize, and resolve these life-endangering conditions. This article will detail the cognitive hypnotic world of DD patients, the relational spaces of the ego states, and the triphasic treatment mode to successfully resolve the dissociative pathology. Structured and phase appropriate hypnotic interventions will be described.

Tracking Potentiating States of Dissociation: An Intensive Clinical Case Study of Sleep, Daydreaming, Mood, and Depersonalization/Derealization.

PubMed

Poerio, Giulia L; Kellett, Stephen; Totterdell, Peter

2016-01-01

This study examined in real time the role of sleep and daydreaming as potentiating states for subsequent dissociation in depersonalization/derealization disorder (DDD). Research and theory suggests that dissociation may be exacerbated and maintained by a labile sleep-wake cycle in which "dream-like" mentation intrudes into waking life and fuels dissociative symptoms. We explore and extend this idea by examining the state of daydreaming in dissociation. Daydreaming is a state of consciousness between dreaming and waking cognition that involves stimulus-independent and task-unrelated mentation. We report the results of a unique intensive N = 1 study with an individual meeting diagnostic criteria for DDD. Using experience-sampling methodology, the participant rated (six times daily for 40 days) current daydreaming, mood, and dissociative symptoms. At the start of each day sleep quality and duration was also rated. Daydreaming was reported on 45% of occasions and significantly predicted greater dissociation, in particular when daydreams were repetitive and negative (but not fanciful) in content. These relationships were mediated by feelings of depression and anxiety. Sleep quality but not duration was a negative predictor of daily dissociation and also negatively predicted depression but not anxiety. Findings offer initial evidence that the occurrence and content of daydreams may act as potentiating states for heightened, in the moment, dissociation. The treatment implications of targeting sleep and daydreaming for dissociative disorders are discussed.

Tracking Potentiating States of Dissociation: An Intensive Clinical Case Study of Sleep, Daydreaming, Mood, and Depersonalization/Derealization

PubMed Central

Poerio, Giulia L.; Kellett, Stephen; Totterdell, Peter

2016-01-01

This study examined in real time the role of sleep and daydreaming as potentiating states for subsequent dissociation in depersonalization/derealization disorder (DDD). Research and theory suggests that dissociation may be exacerbated and maintained by a labile sleep-wake cycle in which “dream-like” mentation intrudes into waking life and fuels dissociative symptoms. We explore and extend this idea by examining the state of daydreaming in dissociation. Daydreaming is a state of consciousness between dreaming and waking cognition that involves stimulus-independent and task-unrelated mentation. We report the results of a unique intensive N = 1 study with an individual meeting diagnostic criteria for DDD. Using experience-sampling methodology, the participant rated (six times daily for 40 days) current daydreaming, mood, and dissociative symptoms. At the start of each day sleep quality and duration was also rated. Daydreaming was reported on 45% of occasions and significantly predicted greater dissociation, in particular when daydreams were repetitive and negative (but not fanciful) in content. These relationships were mediated by feelings of depression and anxiety. Sleep quality but not duration was a negative predictor of daily dissociation and also negatively predicted depression but not anxiety. Findings offer initial evidence that the occurrence and content of daydreams may act as potentiating states for heightened, in the moment, dissociation. The treatment implications of targeting sleep and daydreaming for dissociative disorders are discussed. PMID:27582722

Predictors of trait dissociation and peritraumatic dissociation induced via cold pressor.

PubMed

Gómez-Pérez, Lydia; López-Martínez, Alicia Eva; Asmundson, Gordon John Glenn

2013-11-30

Understanding which factors predict individual dissociative response during stressful situations is important to clarify the nature of dissociation and the mechanisms associated to its use as a coping strategy. The present study examined (1) whether experiential avoidance (EA), anxiety sensitivity (AS), depressive symptoms, and state anxiety concurrently predicted trait dissociation (TD)-absorption, amnesia, depersonalization, and total TD scores-and laboratory induced dissociation (LID); and (2) whether TD and catastrophizing predicted LID. We also examined whether catastrophizing mediated the relationships between both AS and depressive symptoms and LID. A total of 101 female undergraduate students participated in a cold pressor task, which significantly induced dissociation. Results of hierarchical regression analyses showed that AS at Time 1 (9 months before the experimental session), as well as depressive symptoms and catastrophizing at the time of the experiment (Time 2), predicted LID at Time 2. Depressive symptoms at Time 2 predicted total TD, absorption, and amnesia scores. AS at Time 1 and depressive symptoms at Time 2 predicted depersonalization. AS, depressive symptoms, and catastrophizing seem to facilitate the use of dissociative strategies by healthy individuals, even in response to non-traumatic but discomforting stress. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Mentalization and dissociation in the context of trauma: Implications for child psychopathology.

PubMed

Ensink, Karin; Bégin, Michaël; Normandin, Lina; Godbout, Natacha; Fonagy, Peter

2017-01-01

Dissociation is a common reaction subsequent to childhood sexual abuse (CSA) and has been identified as a risk factor for child psychopathology. There is also evidence that mentalization contributes to resilience in the context of abuse. However, at this stage little is known regarding the relationship between mentalization and dissociation, and their respective contributions to psychopathology. The aim of this study was to examine pathways from CSA to depressive symptoms, externalizing behaviour difficulties and sexualized behaviour through mentalization and dissociation. These pathways were examined in a sample of 168 mother-child dyads, including 74 dyads where children (aged 7-12) had histories of sexual abuse. Maternal mentalization was assessed using the Parent Development Interview-Revised and children's mentalization was assessed using the Child Reflective Functioning Scale. Children completed the Child Depression Inventory and parents completed the Child Dissociative Checklist, the Child Behavior Checklist and the Child Sexual Behavior Inventory. Direct and indirect paths from CSA to child psychopathology via children's mentalization and dissociation were examined using Mplus. Distinct paths from abuse to psychopathology were identified. Child mentalization partially mediated the relationship between CSA and depressive symptoms. The effects of CSA on externalizing symptoms and sexualized behaviour difficulties were sequentially mediated through mentalization and dissociation.

The prevalence of deliberate self-harm and its relationships to trauma and dissociation among Iranian young adults.

PubMed

Nobakht, Habib Niyaraq; Dale, Karl Yngvar

2017-01-01

This study aims to investigate the prevalence of deliberate self-harm and its relationships to childhood and recent trauma and different patterns of dissociative features. A total of 100 male and 100 female college students were administered a 58-item questionnaire designed to detect the extent of dissociation, deliberate self-harm, and trauma history. Participants with deliberate self-harm behaviors reported more traumatic experiences and dissociative features than participants without such behaviors. Furthermore, the prevalence of deliberate self-harm (i.e., 40.5%) was similar to previous studies on college student populations. However, and contrary to earlier research, deliberate self-harm was significantly more prevalent among men (48%) than women (33%). The findings support the notion that trauma, pathological dissociation, and depersonalization/derealization play important functional roles in self-harm behaviors. From this perspective, it is feasible to understand individuals who engage in self-harm as either escaping from uncomfortable dissociative states or experiencing an infra-psychological conflict in which one dissociative part of the self is being abusive toward another.

Characteristics of child maltreatment and their relation to dissociation, posttraumatic stress symptoms, and depression in adult psychiatric patients.

PubMed

Mueller-Pfeiffer, Christoph; Moergeli, Hanspeter; Schumacher, Sonja; Martin-Soelch, Chantal; Wirtz, Gustav; Fuhrhans, Christoph; Hindermann, Esther; Rufer, Michael

2013-06-01

Little is known about the influence of particular characteristics of childhood maltreatment, such as developmental stage, relationship to the perpetrator, and nature of the trauma, on adult psychopathology. The effects of childhood maltreatment were assessed in adult psychiatric patients (N = 287) using self-rating scales and diagnostic checklists. Maltreatment was strongly associated with dissociation. This relationship was observed for all childhood developmental stages and was strongest when the perpetrator was outside the family. Dissociation was more strongly correlated with childhood emotional abuse and sexual harassment than with sexual or physical abuse. Childhood sexual abuse was found to be associated with symptoms of posttraumatic stress. The findings suggest that dissociation is a relatively specific consequence of childhood maltreatment that is largely independent of the familial relationship to the perpetrator or the child's developmental stage.

Dissociative Reactions to Incest.

ERIC Educational Resources Information Center

Hall, J. Mark

In contrast to Freud's later and revised view of the etiology of hysterical, or dissociative, symptoms, it is now known that real, and not fantasized, sexual experiences in childhood are experienced in disociative symptomatology. It is useful to understand that incest involves both traumatic events, that is, incidents of sexual violation per se,…

Re-Examining Dissociations between Remembering and Knowing: Binary Judgments vs. Independent Ratings

ERIC Educational Resources Information Center

Brown, Aaron A.; Bodner, Glen E.

2011-01-01

When participants must classify their recognition experiences as remembering or knowing, variables often have dissociative effects on the two judgments. In contrast, when participants independently rate recollection "and" familiarity only parallel effects have been reported. To investigate this discrepancy we compared the effects of masked priming…

Dissociative Contributions of Semantic and Lexical-Phonological Information to Immediate Recognition

ERIC Educational Resources Information Center

Nishiyama, Ryoji

2013-01-01

Several neuropsychological studies have reported that patients with memory deficits exhibit a dissociation of effects attributed to semantic and lexical-phonological information in verbal working memory (e.g., Reilly, Martin, & Grossman, 2005; Romani & Martin, 1999). The present study reports on 3 experiments conducted with individuals without…

Dissociations in Processing Derivational Morphology: The Right Basal Ganglia Involvement

ERIC Educational Resources Information Center

Marangolo, Paola; Piras, Fabrizio

2008-01-01

In the neuropsychological literature, there is converging evidence for a dominant role of the left hemisphere in morphological processing. However, two right hemisphere patients were described with a clear dissociation between impaired derivational morphology and preserved inflectional processing. A recent fMRI experiment confirmed the involvement…

The OI/1S/ state - Its quenching by O2 and formation by the dissociative recombination of vibrationally excited O2/+/ ions

NASA Technical Reports Server (NTRS)

Zipf, E. C.

1979-01-01

The rate coefficient for the quenching of metastable O(1S) atoms by O2 was measured as a function of temperature from 250 to 550 K. The resulting Arrhenius expression correlates well with previous laboratory work. It is suggested that the much larger value of the rate coefficient inferred from an analysis of artificial auroral experiment, Precede, may be explained by overestimation of the contribution of O(1S) production from O2(+) dissociative recombination. The possibility that O(1S) atoms are produced only by the dissociative recombination of vibrationally excited O2(+) ions is examined; such excited ions would not exist in the Precede experiment because of the rapid cooling of the ions by resonant charge transfer processes.

Role of ultrafast dissociation in the fragmentation of chlorinated methanes

NASA Astrophysics Data System (ADS)

Kokkonen, E.; Jänkälä, K.; Patanen, M.; Cao, W.; Hrast, M.; Bučar, K.; Žitnik, M.; Huttula, M.

2018-05-01

Photon-induced fragmentation of a full set of chlorinated methanes (CH3Cl, CH2Cl2, CHCl3, CCl4) has been investigated both experimentally and computationally. Using synchrotron radiation and electron-ion coincidence measurements, the dissociation processes were studied after chlorine 2p electron excitation. Experimental evidence for CH3Cl and CH2Cl2 contains unique features suggesting that fast dissociation processes take place. By contrast, CHCl3 and CCl4 molecules do not contain the same features, hinting that they experience alternative mechanisms for dissociation and charge migration. Computational work indicates differing rates of charge movement after the core-excitation, which can be used to explain the differences observed experimentally.

Role of ultrafast dissociation in the fragmentation of chlorinated methanes.

PubMed

Kokkonen, E; Jänkälä, K; Patanen, M; Cao, W; Hrast, M; Bučar, K; Žitnik, M; Huttula, M

2018-05-07

Photon-induced fragmentation of a full set of chlorinated methanes (CH 3 Cl, CH 2 Cl 2 , CHCl 3 , CCl 4 ) has been investigated both experimentally and computationally. Using synchrotron radiation and electron-ion coincidence measurements, the dissociation processes were studied after chlorine 2p electron excitation. Experimental evidence for CH 3 Cl and CH 2 Cl 2 contains unique features suggesting that fast dissociation processes take place. By contrast, CHCl 3 and CCl 4 molecules do not contain the same features, hinting that they experience alternative mechanisms for dissociation and charge migration. Computational work indicates differing rates of charge movement after the core-excitation, which can be used to explain the differences observed experimentally.

The Influence of the Dissociative Subtype of Posttraumatic Stress Disorder on Treatment Efficacy in Female Veterans and Active Duty Service Members

PubMed Central

Wolf, Erika J.; Lunney, Carole A.; Schnurr, Paula P.

2016-01-01

Objective A dissociative subtype of posttraumatic stress disorder (PTSD) was recently added to the Diagnostic and Statistical Manual-5 (American Psychiatric Association, 2013) and is thought to be associated with poor PTSD treatment response. Method We used latent growth curve modeling to examine data from a randomized controlled trial of Prolonged Exposure and Present-Centered Therapy for PTSD in a sample of 284 female veterans and active duty service members with PTSD to test the association between the dissociative subtype and treatment response. Results Individuals with the dissociative subtype (defined using latent profile analysis) had a flatter slope (p = .008) compared to those with high PTSD symptoms and no dissociation such that the former group showed, on average, a 9.75 (95% CI = -16.94 to -2.57) lesser decrease in PTSD severity scores on the Clinician Administered PTSD Scale (Blake et al., 1995) over the course of the trial. However, this effect was small in magnitude. Dissociative symptoms decreased markedly among those with the subtype, though neither treatment explicitly addressed such symptoms. There were no differences as a function of treatment type. Conclusions Results raise doubt about the common clinical perception that exposure therapy is not effective or appropriate for individuals who have PTSD and dissociation and provide empirical support for the use of exposure treatment for individuals with the dissociative subtype of PTSD. Public Health Significance . This study found that female veterans and active duty service members with the dissociative subtype of posttraumatic stress disorder (PTSD) did not respond as well to PTSD treatment with Prolonged Exposure or Present-Centered Therapy as did those without the subtype. However, both PTSD and dissociation symptoms did improve markedly in the dissociative group, suggesting that the dissociative subtype is not a contraindication for the use of empirically supported treatments for PTSD. PMID:26167946

Shot through with voices: Dissociation mediates the relationship between varieties of inner speech and auditory hallucination proneness

PubMed Central

Alderson-Day, Ben; McCarthy-Jones, Simon; Bedford, Sarah; Collins, Hannah; Dunne, Holly; Rooke, Chloe; Fernyhough, Charles

2014-01-01

Inner speech is a commonly experienced but poorly understood phenomenon. The Varieties of Inner Speech Questionnaire (VISQ; McCarthy-Jones & Fernyhough, 2011) assesses four characteristics of inner speech: dialogicality, evaluative/motivational content, condensation, and the presence of other people. Prior findings have linked anxiety and proneness to auditory hallucinations (AH) to these types of inner speech. This study extends that work by examining how inner speech relates to self-esteem and dissociation, and their combined impact upon AH-proneness. 156 students completed the VISQ and measures of self-esteem, dissociation and AH-proneness. Correlational analyses indicated that evaluative inner speech and other people in inner speech were associated with lower self-esteem and greater frequency of dissociative experiences. Dissociation and VISQ scores, but not self-esteem, predicted AH-proneness. Structural equation modelling supported a mediating role for dissociation between specific components of inner speech (evaluative and other people) and AH-proneness. Implications for the development of “hearing voices” are discussed. PMID:24980910

Dissociation coefficients of protein adsorption to nanoparticles as quantitative metrics for description of the protein corona: A comparison of experimental techniques and methodological relevance.

PubMed

Hühn, Jonas; Fedeli, Chiara; Zhang, Qian; Masood, Atif; Del Pino, Pablo; Khashab, Niveen M; Papini, Emanuele; Parak, Wolfgang J

2016-06-01

Protein adsorption to nanoparticles is described as a chemical reaction in which proteins attach to binding sites on the nanoparticle surface. This process is defined by a dissociation coefficient, which tells how many proteins are adsorbed per nanoparticle in dependence of the protein concentration. Different techniques to experimentally determine dissociation coefficients of protein adsorption to nanoparticles are reviewed. Results of more than 130 experiments in which dissociation coefficients have been determined are compared. Data show that different methods, nanoparticle systems, and proteins can lead to significantly different dissociation coefficients. However, we observed a clear tendency of smaller dissociation coefficients upon less negative towards more positive zeta potentials of the nanoparticles. The zeta potential thus is a key parameter influencing protein adsorption to the surface of nanoparticles. Our analysis highlights the importance of the characterization of the parameters governing protein-nanoparticle interaction for quantitative evaluation and objective literature comparison. Copyright © 2015 Elsevier Ltd. All rights reserved.

Full versus divided attention and implicit memory performance.

PubMed

Wolters, G; Prinsen, A

1997-11-01

Effects of full and divided attention during study on explicit and implicit memory performance were investigated in two experiments. Study time was manipulated in a third experiment. Experiment 1 showed that both similar and dissociative effects can be found in the two kinds of memory test, depending on the difficulty of the concurrent tasks used in the divided-attention condition. In this experiment, however, standard implicit memory tests were used and contamination by explicit memory influences cannot be ruled out. Therefore, in Experiments 2 and 3 the process dissociation procedure was applied. Manipulations of attention during study and of study time clearly affected the controlled (explicit) memory component, but had no effect on the automatic (implicit) memory component. Theoretical implications of these findings are discussed.

Infant attachment insecurity and dissociative symptomatology: findings from the NICHD Study of Early Child Care and Youth Development.

PubMed

Haltigan, John D; Roisman, Glenn I

2015-01-01

Based on data from the NICHD Study of Early Child Care and Youth Development (N = 1,149), the current article provides the first large-sample investigation of associations between different forms of infant attachment insecurity and dissociative symptomatology from childhood through midadolescence as measured by scales based on the mother, teacher, and youth self-report versions of the Achenbach System of Empirically Based Assessments. Findings did not replicate the previously reported and highly cited evidence that infant attachment disorganization is associated with dissociative symptomatology. In contrast, correlations of small magnitude were observed between infant avoidance and dissociative symptomatology, as assessed by teachers and mothers (but not self-report). Results were not moderated by contextual risk. Limitations of the study included the absence of measures of maltreatment and interpersonal trauma, leaving open the possibility that infant attachment disorganization is a diathesis for later dissociation in the context of severe and/or chronic trauma. Nevertheless, the present results strongly indicate the need for additional research exploring the possible role of environmental factors in the development of dissociative symptomatology. © 2014 Michigan Association for Infant Mental Health.

Stark shift and electric-field-induced dissociation of excitons in monolayer MoS2 and h BN /MoS2 heterostructures

NASA Astrophysics Data System (ADS)

Haastrup, Sten; Latini, Simone; Bolotin, Kirill; Thygesen, Kristian S.

2016-07-01

Efficient conversion of photons into electrical current in two-dimensional semiconductors requires, as a first step, the dissociation of the strongly bound excitons into free electrons and holes. Here we calculate the dissociation rates and energy shift of excitons in monolayer MoS2 as a function of an applied in-plane electric field. The dissociation rates are obtained as the inverse lifetime of the resonant states of a two-dimensional hydrogenic Hamiltonian which describes the exciton within the Mott-Wannier model. The resonances are computed using complex scaling, and the effective masses and screened electron-hole interaction defining the hydrogenic Hamiltonian are computed from first principles. For field strengths above 0.1 V/nm the dissociation lifetime is shorter than 1 ps, which is below the lifetime associated with competing decay mechanisms. Interestingly, encapsulation of the MoS2 layer in just two layers of hexagonal boron nitride (h BN ), enhances the dissociation rate by around one order of magnitude due to the increased screening. This shows that dielectric engineering is an effective way to control exciton lifetimes in two-dimensional materials.

Strategies to mitigate dissociative and psychotomimetic effects of ketamine in the treatment of major depressive episodes: a narrative review.

PubMed

Cooper, Matthew D; Rosenblat, Joshua D; Cha, Danielle S; Lee, Yena; Kakar, Ron; McIntyre, Roger S

2017-09-01

Objectives Replicated evidence has demonstrated that ketamine exerts rapid-acting and potent antidepressant effects. Notwithstanding, its promise to mitigate depressive symptoms and suicidality in antidepressant-resistant populations, several limitations and safety concerns accompany ketamine including, but not limited to, the potential for abuse and psychotomimetic/dissociative experiences. The focus of the current narrative review is to synthesise available evidence of strategies that may mitigate and fully prevent treatment-emergent psychotomimetic and dissociative effects associated with ketamine administration. Methods PubMed, Google Scholar and ClinicalTrials.gov were searched for relevant articles. Results Potential avenues investigated to minimise psychotomimetic effects associated with ketamine administration include the following: (1) altering dosing and infusion rates; (2) route of administration; (3) enantiomer choice; (4) co-administration with mood stabilisers of antipsychotics; and (5) use of alternative N-methyl-d-aspartate (NMDA)-modulating agents. Emerging evidence indicates that dissociative experiences can be significantly mitigated by using an intranasal route of administration, lower dosages, or use of alternative NMDA-modulating agents, namely lanicemine (AZD6765) and GLYX-13. Conclusions Currently, intranasal administration presents as the most promising strategy to mitigate dissociative and psychotomimetic effects; however, studies of strategies to mitigate the adverse events of ketamine are limited in number and quality and thus further investigation is still needed.

Women's Auto/Biography and Dissociative Identity Disorder: Implications for Mental Health Practice.

PubMed

Tomlinson, Kendal; Baker, Charley

2017-09-06

Dissociative Identity Disorder (DID) is an uncommon disorder that has long been associated with exposure to traumatic stressors exceeding manageable levels commonly encompassing physical, psychological and sexual abuse in childhood that is prolonged and severe in nature. In DID, dissociation continues after the traumatic experience and produces a disruption in identity where distinct personality states develop. These personalities are accompanied by variations in behaviour, emotions, memory, perception and cognition. The use of literature in psychiatry can enrich comprehension over the subjective experience of a disorder, and the utilisation of 'illness narratives' in nursing research have been considered a way of improving knowledge about nursing care and theory development. This research explores experiences of DID through close textual reading and thematic analysis of five biographical and autobiographical texts, discussing the lived experience of the disorder. This narrative approach aims to inform empathetic understanding and support the facilitation of therapeutic alliances in mental healthcare for those experiencing the potentially debilitating and distressing symptoms of DID. Although controversies surrounding the biomedical diagnosis of DID are important to consider, the lived experiences of those who mental health nurses encounter should be priority.

Dissociations of the number and precision of visual short-term memory representations in change detection.

PubMed

Xie, Weizhen; Zhang, Weiwei

2017-11-01

The present study dissociated the number (i.e., quantity) and precision (i.e., quality) of visual short-term memory (STM) representations in change detection using receiver operating characteristic (ROC) and experimental manipulations. Across three experiments, participants performed both recognition and recall tests of visual STM using the change-detection task and the continuous color-wheel recall task, respectively. Experiment 1 demonstrated that the estimates of the number and precision of visual STM representations based on the ROC model of change-detection performance were robustly correlated with the corresponding estimates based on the mixture model of continuous-recall performance. Experiments 2 and 3 showed that the experimental manipulation of mnemonic precision using white-noise masking and the experimental manipulation of the number of encoded STM representations using consolidation masking produced selective effects on the corresponding measures of mnemonic precision and the number of encoded STM representations, respectively, in both change-detection and continuous-recall tasks. Altogether, using the individual-differences (Experiment 1) and experimental dissociation (Experiment 2 and 3) approaches, the present study demonstrated the some-or-none nature of visual STM representations across recall and recognition.

X-ray Computed Tomography Observation of Methane Hydrate Dissociation

USGS Publications Warehouse

Tomutsa, L.; Freifeld, B.; Kneafsey, T.J.; Stern, L.A.

2002-01-01

Deposits of naturally occurring methane hydrate have been identified in permafrost and deep oceanic environments with global reserves estimated to be twice the total amount of energy stored in fossil fuels. The fundamental behavior of methane hydrate in natural formations, while poorly understood, is of critical importance if the economic recovery of methane from hydrates is to be accomplished. In this study, computed X-ray tomography (CT) scanning is used to image an advancing dissociation front in a heterogeneous gas hydrate/sand sample at 0.1 MPa. The cylindrical methane hydrate and sand aggregate, 2.54 cm in diameter and 6.3 cm long, was contained in a PVC sample holder that was insulated on all but one end. At the uninsulated end, the dissociated gas was captured and the volume of gas monitored. The sample was initially imaged axially using X-ray CT scanning within the methane hydrate stability zone by keeping the sample temperature at 77??K. Subsequently, as the sample warmed through the methane hydrate dissociation point at 194??K and room pressure, gas was produced and the temperature at the bottom of the sample plug was monitored while CT images were acquired. The experiment showed that CT imaging can resolve the reduction in density (as seen by a reduction in beam attenuation) of the hydrate/sand aggregate due to the dissociation of methane hydrate. In addition, a comparison of CT images with gas flow and temperature measurements reveals that the CT scanner is able to resolve accurately and spatially the advancing dissociation front. Future experiments designed to better understand the thermodynamics of hydrate dissociation are planned to take advantage of the temporal and spatial resolution that the CT scanner provides.

The influence of the dissociative subtype of posttraumatic stress disorder on treatment efficacy in female veterans and active duty service members.

PubMed

Wolf, Erika J; Lunney, Carole A; Schnurr, Paula P

2016-01-01

A dissociative subtype of posttraumatic stress disorder (PTSD) was recently added to the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; American Psychiatric Association, 2013) and is thought to be associated with poor PTSD treatment response. We used latent growth curve modeling to examine data from a randomized controlled trial of prolonged exposure and present-centered therapy for PTSD in a sample of 284 female veterans and active duty service members with PTSD to test the association between the dissociative subtype and treatment response. Individuals with the dissociative subtype (defined using latent profile analysis) had a flatter slope (p = .008) compared with those with high PTSD symptoms and no dissociation, such that the former group showed, on average, a 9.75 (95% confidence interval [-16.94, -2.57]) lesser decrease in PTSD severity scores on the Clinician Administered PTSD Scale (Blake et al., 1995) over the course of the trial. However, this effect was small in magnitude. Dissociative symptoms decreased markedly among those with the subtype, though neither treatment explicitly addressed such symptoms. There were no differences as a function of treatment type. Results raise doubt about the common clinical perception that exposure therapy is not effective or appropriate for individuals who have PTSD and dissociation, and provide empirical support for the use of exposure treatment for individuals with the dissociative subtype of PTSD. (c) 2015 APA, all rights reserved).

A wireless centrifuge force microscope (CFM) enables multiplexed single-molecule experiments in a commercial centrifuge.

PubMed

Hoang, Tony; Patel, Dhruv S; Halvorsen, Ken

2016-08-01

The centrifuge force microscope (CFM) was recently introduced as a platform for massively parallel single-molecule manipulation and analysis. Here we developed a low-cost and self-contained CFM module that works directly within a commercial centrifuge, greatly improving accessibility and ease of use. Our instrument incorporates research grade video microscopy, a power source, a computer, and wireless transmission capability to simultaneously monitor many individually tethered microspheres. We validated the instrument by performing single-molecule force shearing of short DNA duplexes. For a 7 bp duplex, we observed over 1000 dissociation events due to force dependent shearing from 2 pN to 12 pN with dissociation times in the range of 10-100 s. We extended the measurement to a 10 bp duplex, applying a 12 pN force clamp and directly observing single-molecule dissociation over an 85 min experiment. Our new CFM module facilitates simple and inexpensive experiments that dramatically improve access to single-molecule analysis.

Rewarded remembering: dissociations between self-rated motivation and memory performance.

PubMed

Ngaosuvan, Leonard; Mäntylä, Timo

2005-08-01

People often claim that they perform better in memory performance tasks when they are more motivated. However, past research has shown minimal effects of motivation on memory performance when factors contributing to item-specific biases during encoding and retrieval are taken into account. The purpose of the present study was to examine the generality of this apparent dissociation by using more sensitive measures of experienced motivation and memory performance. Extrinsic motivation was manipulated through competition instructions, and subjective ratings of intrinsic and extrinsic motivation were obtained before and after study instructions. Participants studied a series of words, and memory performance was assessed by content recall (Experiment 1) and source recall (Experiment 2). Both experiments showed dissociation between subjective ratings of extrinsic motivation and actual memory performance, so that competition increased self-rated extrinsic motivation but had no effects on memory performance, including source recall. Inconsistent with most people's expectations, the findings suggest that extrinsic motivation has minimal effects on memory performance.

Measuring automatic retrieval: a comparison of implicit memory, process dissociation, and speeded response procedures.

PubMed

Horton, Keith D; Wilson, Daryl E; Vonk, Jennifer; Kirby, Sarah L; Nielsen, Tina

2005-07-01

Using the stem completion task, we compared estimates of automatic retrieval from an implicit memory task, the process dissociation procedure, and the speeded response procedure. Two standard manipulations were employed. In Experiment 1, a depth of processing effect was found on automatic retrieval using the speeded response procedure although this effect was substantially reduced in Experiment 2 when lexical processing was required of all words. In Experiment 3, the speeded response procedure showed an advantage of full versus divided attention at study on automatic retrieval. An implicit condition showed parallel effects in each study, suggesting that implicit stem completion may normally provide a good estimate of automatic retrieval. Also, we replicated earlier findings from the process dissociation procedure, but estimates of automatic retrieval from this procedure were consistently lower than those from the speeded response procedure, except when conscious retrieval was relatively low. We discuss several factors that may contribute to the conflicting outcomes, including the evidence for theoretical assumptions and criterial task differences between implicit and explicit tests.

Childhood maltreatment and intimate partner violence in dissociative disorder patients.

PubMed

Webermann, Aliya R; Brand, Bethany L; Chasson, Gregory S

2014-01-01

Childhood maltreatment (CM) is a risk factor for subsequent intimate partner violence (IPV) in adulthood, with high rates of retrospectively reported CM among IPV victims and perpetrators. A theorized mechanism of the link between CM and IPV is dissociation. Dissociation may allow perpetrators of violence to remain emotionally distant from their behavior and minimize empathy toward those they victimize, enabling them to commit acts of violence similar to their own experiences. Indeed, elevated rates of dissociation and dissociative disorders (DD) have been found among IPV survivors and perpetrators. In addition, in pilot studies, DD clinicians have reported high levels of violent behavior among DD patients. The present study investigates IPV among DD patients with Dissociative Identity Disorder and Dissociative Disorder Not Otherwise Specified, a group with CM rates of 80-95% and severe dissociative symptoms. DD clinicians reported on rates of CM and IPV among 275 DD patients in outpatient treatment. DD patients also completed a self-report measure of dissociation. Analyses assessed the associations between CM typologies and IPV, as well as trait dissociation and IPV. Physical and emotional child abuse were associated with physical IPV, and childhood witnessing of domestic violence (DV) and childhood neglect were associated with emotional IPV. The present study is the first to provide empirical support for a possible CM to adult IPV developmental trajectory among DD patients. Future research is needed to better understand the link between CM and IPV among those with trauma and DD.

Exploring evidence of a dissociative subtype in PTSD: Baseline symptom structure, etiology, and treatment efficacy for those who dissociate.

PubMed

Burton, Mark S; Feeny, Norah C; Connell, Arin M; Zoellner, Lori A

2018-05-01

With the inclusion of a dissociative subtype, recent changes to the DSM-5 diagnosis of posttraumatic stress disorder (PTSD) have emphasized the role of dissociation in the experience and treatment of the disorder. However, there is a lack of research exploring the clinical impact for highly dissociative groups receiving treatment for PTSD. The current study examined the presence and clinical impact of a dissociative subtype in a sample of individuals receiving treatment for chronic PTSD. This study used latent transition analyses (LTA), an expanded form of latent profile analyses (LPA), to examine latent profiles of PTSD and dissociation symptoms before and after treatment for individuals (N = 200) receiving prolonged exposure (PE) or sertraline treatment for chronic PTSD. The best fitting LTA model was one with a 4-class solution at both pretreatment and posttreatment. There was a latent class at pretreatment with higher levels of dissociative symptoms. However, this class was also marked by higher reexperiencing symptoms, and membership was not predicted by chronic child abuse. Further, although those in the class were less likely to transition to the responder class overall, this was not the case for exposure-based treatment specifically. These findings are not in line with the dissociative-subtype theoretical literature that proposes those who dissociate represent a clinically distinct group that may respond worse to exposure-based treatments for PTSD. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Childhood maltreatment and intimate partner violence in dissociative disorder patients

PubMed Central

Webermann, Aliya R.; Brand, Bethany L.; Chasson, Gregory S.

2014-01-01

Background Childhood maltreatment (CM) is a risk factor for subsequent intimate partner violence (IPV) in adulthood, with high rates of retrospectively reported CM among IPV victims and perpetrators. A theorized mechanism of the link between CM and IPV is dissociation. Dissociation may allow perpetrators of violence to remain emotionally distant from their behavior and minimize empathy toward those they victimize, enabling them to commit acts of violence similar to their own experiences. Indeed, elevated rates of dissociation and dissociative disorders (DD) have been found among IPV survivors and perpetrators. In addition, in pilot studies, DD clinicians have reported high levels of violent behavior among DD patients. Objective The present study investigates IPV among DD patients with Dissociative Identity Disorder and Dissociative Disorder Not Otherwise Specified, a group with CM rates of 80–95% and severe dissociative symptoms. Methods DD clinicians reported on rates of CM and IPV among 275 DD patients in outpatient treatment. DD patients also completed a self-report measure of dissociation. Analyses assessed the associations between CM typologies and IPV, as well as trait dissociation and IPV. Results Physical and emotional child abuse were associated with physical IPV, and childhood witnessing of domestic violence (DV) and childhood neglect were associated with emotional IPV. Conclusions The present study is the first to provide empirical support for a possible CM to adult IPV developmental trajectory among DD patients. Future research is needed to better understand the link between CM and IPV among those with trauma and DD. PMID:25279109

Novel Cross-Slip Mechanism of Pyramidal Screw Dislocations in Magnesium.

PubMed

Itakura, Mitsuhiro; Kaburaki, Hideo; Yamaguchi, Masatake; Tsuru, Tomohito

2016-06-03

Compared to cubic metals, whose primary slip mode includes twelve equivalent systems, the lower crystalline symmetry of hexagonal close-packed metals results in a reduced number of equivalent primary slips and anisotropy in plasticity, leading to brittleness at the ambient temperature. At higher temperatures, the ductility of hexagonal close-packed metals improves owing to the activation of secondary ⟨c+a⟩ pyramidal slip systems. Thus, understanding the fundamental properties of corresponding dislocations is essential for the improvement of ductility at the ambient temperature. Here, we present the results of large-scale ab initio calculations for ⟨c+a⟩ pyramidal screw dislocations in magnesium and show that their slip behavior is a stark counterexample to the conventional wisdom that a slip plane is determined by the stacking fault plane of dislocations. A stacking fault between dissociated partial dislocations can assume a nonplanar shape with a negligible energy cost and can migrate normal to its plane by a local shuffling of atoms. Partial dislocations dissociated on a {21[over ¯]1[over ¯]2} plane "slither" in the {011[over ¯]1} plane, dragging the stacking fault with them in response to an applied shear stress. This finding resolves the apparent discrepancy that both {21[over ¯]1[over ¯]2} and {011[over ¯]1} slip traces are observed in experiments while ab initio calculations indicate that dislocations preferably dissociate in the {21[over ¯]1[over ¯]2} planes.

Combustion of Methane Hydrate

NASA Astrophysics Data System (ADS)

Roshandell, Melika

A significant methane storehouse is in the form of methane hydrates on the sea floor and in the arctic permafrost. Methane hydrates are ice-like structures composed of water cages housing a guest methane molecule. This caged methane represents a resource of energy and a potential source of strong greenhouse gas. Most research related to methane hydrates has been focused on their formation and dissociation because they can form solid plugs that complicate transport of oil and gas in pipelines. This dissertation explores the direct burning of these methane hydrates where heat from the combustion process dissociates the hydrate into water and methane, and the released methane fuels the methane/air diffusion flame heat source. In contrast to the pipeline applications, very little research has been done on the combustion and burning characteristics of methane hydrates. This is the first dissertation on this subject. In this study, energy release and combustion characteristics of methane hydrates were investigated both theoretically and experimentally. The experimental study involved collaboration with another research group, particularly in the creation of methane hydrate samples. The experiments were difficult because hydrates form at high pressure within a narrow temperature range. The process can be slow and the resulting hydrate can have somewhat variable properties (e.g., extent of clathration, shape, compactness). The experimental study examined broad characteristics of hydrate combustion, including flame appearance, burning time, conditions leading to flame extinguishment, the amount of hydrate water melted versus evaporated, and flame temperature. These properties were observed for samples of different physical size. Hydrate formation is a very slow process with pure water and methane. The addition of small amounts of surfactant increased substantially the hydrate formation rate. The effects of surfactant on burning characteristics were also studied. One finding from the experimental component of the research was that hydrates can burn completely, and that they burn most rapidly just after ignition and then burn steadily when some of the water in the dissociated zone is allowed to drain away. Excessive surfactant in the water creates a foam layer around the hydrate that acts as an insulator. The layer prevents sufficient heat flux from reaching the hydrate surface below the foam to release additional methane and the hydrate flame extinguishes. No self-healing or ice-freezing processes were observed in any of the combustion experiments. There is some variability, but a typical hydrate flame is receiving between one and two moles of water vapor from the liquid dissociated zone of the hydrate for each mole of methane it receives from the dissociating solid region. This limits the flame temperature to approximately 1800 K. In the theoretical portion of the study, a physical model using an energy balance from methane combustion was developed to understand the energy transfer between the three phases of gas, liquid and solid during the hydrate burn. Also this study provides an understanding of the different factors impacting the hydrate's continuous burn, such as the amount of water vapor in the flame. The theoretical study revealed how the water layer thickness on the hydrate surface, and its effect on the temperature gradient through the dissociated zone, plays a significant role in the hydrate dissociation rate and methane release rate. Motivated by the above mentioned observation from the theoretical analysis, a 1-D two-phase numerical simulation based on a moving front model for hydrate dissociation from a thermal source was developed. This model was focused on the dynamic growth of the dissociated zone and its effect on the dissociation rate. The model indicated that the rate of hydrate dissociation with a thermal source is a function of the dissociated zone thickness. It shows that in order for a continuous dissociation and methane release, some of the water from the dissociated zone needs to be drained. The results are consistent with the experimental observations. The understanding derived from the experiments and the numerical model permitted a brief exploration into the potential effects of pressure on the combustion of methane hydrates. The prediction is that combustion should improve under high pressure conditions because the evaporation of water is suppressed allowing more energy into the dissociation. Future experiments are needed to validate these initial findings.

Negative Intrusive Thoughts and Dissociation as Risk Factors for Self-Harm

ERIC Educational Resources Information Center

Batey, Helen; May, Jon; Andrade, Jackie

2010-01-01

Relationships between self-harm and vulnerability factors were studied in a general population of 432 participants, of whom 30% reported some experience of self-harm. This group scored higher on dissociation and childhood trauma, had lower self-worth, and reported more negative intrusive thoughts. Among the non-harming group, 10% scored similarly…

The Relationships of Dissociation and Affective Family Environment with the Intergenerational Cycle of Child Abuse

ERIC Educational Resources Information Center

Narang, D.S.; Contreras, J.M.

2005-01-01

Objective:: The purpose was to test a model that may explain how physically abused children become physically abusive parents. It was predicted that when the family's affective environment is uncohesive, unexpressive, and conflictual, a history of abuse experiences would be associated with elevated dissociation. It was hypothesized that…

The dissociative chemisorption of methane on Ni(100) and Ni(111): Classical and quantum studies based on the reaction path Hamiltonian

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mastromatteo, Michael; Jackson, Bret, E-mail: jackson@chem.umass.edu

Electronic structure methods based on density functional theory are used to construct a reaction path Hamiltonian for CH{sub 4} dissociation on the Ni(100) and Ni(111) surfaces. Both quantum and quasi-classical trajectory approaches are used to compute dissociative sticking probabilities, including all molecular degrees of freedom and the effects of lattice motion. Both approaches show a large enhancement in sticking when the incident molecule is vibrationally excited, and both can reproduce the mode specificity observed in experiments. However, the quasi-classical calculations significantly overestimate the ground state dissociative sticking at all energies, and the magnitude of the enhancement in sticking with vibrationalmore » excitation is much smaller than that computed using the quantum approach or observed in the experiments. The origin of this behavior is an unphysical flow of zero point energy from the nine normal vibrational modes into the reaction coordinate, giving large values for reaction at energies below the activation energy. Perturbative assumptions made in the quantum studies are shown to be accurate at all energies studied.« less

DSMC simulations of shock tube experiments for the dissociation rate of nitrogen

NASA Astrophysics Data System (ADS)

Bird, G. A.

2012-11-01

The DSMC method has been used to simulate the flow associated with several experiments that led to predictions of the dissociation rate in nitrogen. One involved optical interferometry to determine the density behind strong shock wave and the other involved the measurement of the shock tube end-wall pressure after the reflection of a similar shock wave. DSMC calculations for the un-reflected shock wave were made with the older TCE model that converts rate coefficients to reaction cross-sections, with the newer Q-K model that predicts the rates and with a set of reaction cross-sections for nitrogen dissociation from QCT calculations. A comparison of the resulting density profiles with the measured profile provides a test of the validity of the DSMC chemistry models. The DSMC reaction rates were sampled directly in the DSMC calculation, both far downstream where the flow is in equilibrium and in the non-equilibrium region immediately behind the shock. This permits a critical evaluation of data reduction procedures that were employed to deduce the dissociation rate from the measured quantities.

H{sub 2} dissociation due to collisions with He

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohlinger, L.; Forrey, R. C.; Lee, Teck-Ghee

2007-10-15

Cross sections for dissociation of H{sub 2} due to collision with He are calculated for highly excited rovibrational states using the quantum-mechanical coupled-states approximation. An L{sup 2} Sturmian basis set with multiple length scales is used to provide a discrete representation of the H{sub 2} continuum which includes orbiting resonances and a nonresonant background. Cross sections are given over a range of translational energies for both resonant and nonresonant dissociation together with the most important bound-state transitions for many different initial states. The results demonstrate that it is possible to compute converged quantum-mechanical cross sections using basis sets of modestmore » size. It is found that collision-induced dissociation competes with inelastic scattering as a depopulation mechanism for the highly excited states. The relevance of the present calculations to astrophysical models is discussed.« less

Dissociative recombination by frame transformation to Siegert pseudostates: A comparison with a numerically solvable model

NASA Astrophysics Data System (ADS)

Hvizdoš, Dávid; Váňa, Martin; Houfek, Karel; Greene, Chris H.; Rescigno, Thomas N.; McCurdy, C. William; Čurík, Roman

2018-02-01

We present a simple two-dimensional model of the indirect dissociative recombination process. The model has one electronic and one nuclear degree of freedom and it can be solved to high precision, without making any physically motivated approximations, by employing the exterior complex scaling method together with the finite-elements method and discrete variable representation. The approach is applied to solve a model for dissociative recombination of H2 + in the singlet ungerade channels, and the results serve as a benchmark to test validity of several physical approximations commonly used in the computational modeling of dissociative recombination for real molecular targets. The second, approximate, set of calculations employs a combination of multichannel quantum defect theory and frame transformation into a basis of Siegert pseudostates. The cross sections computed with the two methods are compared in detail for collision energies from 0 to 2 eV.

What Hinders Electron Transfer Dissociation (ETD) of DNA Cations?

NASA Astrophysics Data System (ADS)

Hari, Yvonne; Leumann, Christian J.; Schürch, Stefan

2017-12-01

Radical activation methods, such as electron transfer dissociation (ETD), produce structural information complementary to collision-induced dissociation. Herein, electron transfer dissociation of 3-fold protonated DNA hexamers was studied to gain insight into the fragmentation mechanism. The fragmentation patterns of a large set of DNA hexamers confirm cytosine as the primary target of electron transfer. The reported data reveal backbone cleavage by internal electron transfer from the nucleobase to the phosphate linker leading either to a•/ w or d/ z• ion pairs. This reaction pathway contrasts with previous findings on the dissociation processes after electron capture by DNA cations, suggesting multiple, parallel dissociation channels. However, all these channels merely result in partial fragmentation of the precursor ion because the charge-reduced DNA radical cations are quite stable. Two hypotheses are put forward to explain the low dissociation yield of DNA radical cations: it is either attributed to non-covalent interactions between complementary fragments or to the stabilization of the unpaired electron in stacked nucleobases. MS3 experiments suggest that the charge-reduced species is the intact oligonucleotide. Moreover, introducing abasic sites significantly increases the dissociation yield of DNA cations. Consequently, the stabilization of the unpaired electron by π-π-stacking provides an appropriate rationale for the high intensity of DNA radical cations after electron transfer. [Figure not available: see fulltext.

Attosecond control of dissociative ionization of O{sub 2} molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siu, W.; Kelkensberg, F.; Gademann, G.

We demonstrate that dissociative ionization of O{sub 2} can be controlled by the relative delay between an attosecond pulse train (APT) and a copropagating infrared (IR) field. Our experiments reveal a dependence of both the branching ratios between a range of electronic states and the fragment angular distributions on the extreme ultraviolet (XUV) to IR time delay. The observations go beyond adiabatic propagation of dissociative wave packets on IR-induced quasistatic potential energy curves and are understood in terms of an IR-induced coupling between electronic states in the molecular ion.

Dispelling confusion about traumatic dissociative amnesia.

PubMed

McNally, Richard J

2007-09-01

How survivors of trauma remember--or forget--their most terrifying experiences lies at the core of one of the most bitter controversies in psychiatry and psychology: the debate regarding repressed memories of childhood sexual abuse. Most experts hold that traumatic events--those experienced as overwhelmingly terrifying and often life-threatening--are remembered very well; however, traumatic dissociative amnesia theorists disagree. Although acknowledging that traumatic events are usually memorable, these theorists nevertheless claim that a sizable minority of survivors are incapable of remembering their trauma. That is, the memory is stored but dissociated (or "repressed") from awareness. However, the evidence that these theorists adduce in support of the concept of traumatic dissociative amnesia is subject to other, more plausible interpretations. The purpose of this review is to dispel confusion regarding the controversial notion of dissociated (or repressed) memory for trauma and to show how people can recall memories of long-forgotten sexual abuse without these memories first having been repressed.

Monensin inhibits intracellular dissociation of asialoglycoproteins from their receptor

PubMed Central

1983-01-01

Treatment of short-term monolayer cultures of rat hepatocytes with the proton ionophore, monensin, abolishes asialoglycoprotein degradation, despite little effect of the drug on either surface binding of ligand or internalization of prebound ligand. Centrifuging cell homogenates on Percoll density gradients indicates that, as a result of monensin treatment, ligand does not enter lysosomes but sediments instead in a lower density subcellular fraction that is likely an endocytic vesicle. Analyzing the degree of receptor association of intracellular ligand revealed that monensin prevents the dissociation of the receptor-ligand complex that normally occurs subsequent to endocytosis. The weak base, chloroquine, also blocks this intracellular dissociation. Evidence from sequential substitution experiments is presented, indicating that monensin and chloroquine act at the same point in the sequence of events leading to ligand dissociation. These data are discussed in terms of a pH-mediated dissociation of the receptor-ligand complex within a prelysosomal endocytic vesicle. PMID:6304116

Spontaneous and Deliberate Dissociative Symptoms in Military Personnel: Are Such Symptoms Helpful?

DTIC Science & Technology

2013-08-01

Participants completed the Clinician-Administered Dissociative States Scale (CADSS) after a stressful mock-captivity event. They were also asked to indicate...The course consists of didactic and experiential phases. The didactic phase is classroom based: during this phase, students learn the U.S. Code of...Conduct and basic survival skills. The ex- periential phase is one that permits students to put into practice what they have learned. In this phase, they

Modeling of the Structure of Disordered Metallic Alloys and Its Transformation Under Thermal Forcing

NASA Astrophysics Data System (ADS)

Cress, Ryan Paul

The morphology of disordered binary metallic alloys is investigated. The structure of disordered binary metallic alloys is modeled as a randomly close packed (RCP) assembly of atoms. It was observed through a 2-D binary hard sphere experiment that RCP structure can be modeled as a mixture of nano-crystallites and glassy matter. We define the degree of crystallinity as the fraction of atoms contained in nano-crystallites in an RCP medium. Nano-crystallites by size in a crystallite size distribution were determined experimentally to define the morphology of the RCP medium. Both the degree of crystallinity and the crystallite size distribution have been found to be determined by the composition of a given binary mixture. A 2-D Monte Carlo simulation was developed in order to replicate the RCP structure observed in the experiment which is then extended to cases of arbitrary composition. Crystallites were assumed to be spherical with isotropic cross sections. The number of atoms in an individual crystallite in 2-D is simply transformed into the number of atoms in 3-D; we then obtain the crystallite size distribution in 3-D. This experiment accounts for the contribution from the repulsive core of the inter-atomic potential. The attractive part of the potential is recovered by constructing spherical nano-crystallites of a given radius from a crystalline specimen of each given alloy. A structural model of a disordered alloy is thus obtained. With the basic structure of the RCP medium defined, the response to heating would be in the form of changes to the crystallite size distribution. This was first investigated in a hard sphere mechanical oven experiment. The experimental setup consists of a 2-D cell which is driven by two independent stepper motors. The motors drive a binary RCP bed of spheres on a slightly tilted plane according to a chaotic algorithmm. The motors are driven at four different speed settings. The RCP medium was analyzed using a sequence of digital images taken of the beds. The bursts of images provide a Gaussian distribution of particle speeds in x and y directions thus giving rise to the notion of "temperature." This temperature scales with the motor speed settings. The measured average degree of crystallinity is found to decrease as the effective temperature was raised suggesting that nano-crystallites dissociate under thermal forcing. The evolution of a specimen's structure is calculated rigorously by means of the law of mass action formalism. A system of thermal dissociation reaction equations is written out for the set of nano-crystallites according to the 3-D crystallite size distribution. The equilibrium treatment is justified because the energy differences between metastable RCP structures fall within kT. Thermal dissociation of one surface atom at a time is assumed because the energy cost in dissociation of a surface atom on a nano-crystallite is significantly less than that of a multi atom cluster. The full set of reaction equations cover all possible dissociation steps, which may amount to several thousand for a disordered alloy specimen. The primary determining factor in each of these dissociation equations is the dissociation potential or the amount of attractive energy needed to remove a surface atom on a nano-crystallite of a given size. The attractive potential between atoms is calculated using a Lennard-Jones potential between a pair of atoms for which quantum chemistry calculations exist in the literature. All interactions impinged on the surface atom by all other atoms in a crystallite are summed. As the nano-crystallites dissociate due to heating, the structure of the alloy changes, and this leads to modifications of alloy's transport properties. The model is found to predict the melting temperature of various disordered binary alloys as well as refractory metals in good agreement with known data. The structure model for disordered binary alloys gives an excellent characterization of the alloy morphology. It therefore provides fruitful avenues for making predictions about how thermophysical properties of disordered binary alloys change as the alloy temperature is raised by heating.

Fighting the Whole System: Dissociative Identity Disorder, Labeling Theory, and Iatrogenic Doubting.

PubMed

Floris, Jessica; McPherson, Susan

2015-01-01

This research examines how individuals diagnosed with dissociative identity disorder construe their experiences of being labeled with a contested diagnosis. Semistructured interviews were conducted in the United Kingdom with 5 women and 2 men diagnosed with dissociative identity disorder. A framework analysis was conducted. The analysis identified 2 overarching themes: diagnosis cross-examined and navigating care systems. The diagnosis appeared to be continually assessed by participants for its fit with symptoms, and the doubt among professionals seemed to be unhelpfully reflected in participants' attempts to understand and come to terms with their experiences. The findings are considered in light of labeling theory, the iatrogenic effects of professional doubt, and current debates concerning the reliability and validity of psychiatric diagnostic systems that have been reinvigorated by the publication of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.

A Quasi-experimental outcomes analysis of a psychoeducation intervention for pregnant women with abuse-related posttraumatic stress.

PubMed

Rowe, Heather; Sperlich, Mickey; Cameron, Heather; Seng, Julia

2014-01-01

To test the effectiveness of a trauma-specific, psychoeducational intervention for pregnant women with a history of childhood maltreatment on six intrapartum and postpartum psychological outcomes. Quasi-experimental study comparing women from a single-group, pretest-posttest pilot intervention study with women matched from a prospective observational study. Rural and university-based prenatal clinics. Pregnant women entered the study by responding to an advertisement or by referral from a maternity care provider. Women could take part whether or not they met posttraumatic stress disorder diagnostic criteria. Outcomes data exist for 17 pilot intervention study participants and 43 matched observational study participants. Participants in the observational study received usual care. Participants in the pilot intervention study received usual care plus the intervention, a fully manualized, self-study program supported by weekly phone tutoring sessions with a health professional. The National Women's Study PTSD Module, the Peritraumatic Dissociation Experience Questionnaire, the Perception of Care Questionnaire, the Postpartum Depression Screening Scale, the Postpartum Bonding Questionnaire, and a semantic differential appraisal of the labor experience. Participants in the intervention study had better scores on all measures. Differences in means between participants in the intervention study and participants in the observational study equated to medium effect sized for dissociation during labor, rating of labor experience, and perception of care in labor and small effect sizes for postpartum posttraumatic stress disorder (PTSD) symptoms, postpartum depression symptoms, and motherinfant bonding. This trauma-specific intervention reaches and benefits pregnant women with a history of childhood maltreatment. © 2014 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

A quasi-experimental outcomes analysis of a psychoeducation intervention for pregnant women with abuse-related posttraumatic stress

PubMed Central

Rowe, Heather; Sperlich, Mickey; Seng, Julia S.

2015-01-01

Objective To test the effectiveness of a trauma-specific psycho-educational intervention for pregnant women with a history of childhood maltreatment on six intrapartum and postpartum psychological outcomes. Design Quasi-experimental study comparing women from a single-group pretest-posttest pilot intervention study with women matched from a prospective observational study. Setting Rural and university-based prenatal clinics. Participants Pregnant women entered the study by responding to an advertisement or by referral from a maternity care provider. Women could take part whether or not they met posttraumatic stress disorder diagnostic criteria. Outcomes data exist for 17 pilot intervention study participants and 43 matched observational study participants. Interventions Participants in the observational study received usual care. Participants in the pilot intervention study received usual care plus the intervention, a fully manualized self-study program supported by weekly phone tutoring sessions with a health professional. Main Outcome Measures The National Women’s Study PTSD Module; The Peritraumatic Dissociation Experience Questionnaire); The Perception of Care Questionnaire; The Postpartum Depression Screening Scale; The Postpartum Bonding Questionnaire; and a semantic differential appraisal of the labor experience. Results Participants in the intervention study had better scores on all measures. Differences in means between participants in the intervention study and participants in the observational study equated to medium effect sized for dissociation during labor, rating of labor experience, and perception of care in labor, and small effect sizes for postpartum PTSD symptoms, postpartum depression symptoms, and mother-infant bonding. Conclusion This trauma-specific intervention reaches and benefits pregnant women with a history of childhood maltreatment. PMID:24754455

Effects of molecular dissociation on the hydrogen equation of state

NASA Astrophysics Data System (ADS)

Bonev, Stanimir; Schwegler, Eric; Galli, Giulia; Gygi, Francois

2002-03-01

It has been suggested recently(François Gygi and G. Galli, submitted to Phys. Rev. Lett.) that the physical mechanism behind the larger compressibility of liquid deuterium observed in laser shock experiments as compared to ab initio simulations may be related to shock-induced electronic excitations. A possible result of such non-adiabatic processes is hindering of the molecular dissociation. This has motivated us to study the importance of molecular dissociation on the hydrogen equation of state. To this end, we have carried out ab initio molecular dynamics simulations of liquid deuterium where intramolecular dissociation is prevented by the use of bond length contraints. Simulations at both fixed thermodynamic conditions and dynamical simulations of shocked deuterium will be discussed.

A molecular dynamics study of melting and dissociation of tungsten nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Min; Wang, Jun; Fu, Baoqin

2015-12-15

Molecular dynamics simulations were conducted to study the melting and dissociation of free tungsten nanoparticles. For the various interatomic potentials applied, the melting points of the tungsten nanoparticles increased with increasing nanoparticle diameter. Combining these results with the melting point of bulk tungsten in the experiment, the melting point of nanoparticles with diameters ranging from 4 to 12 nm could be determined. As the temperature increases, free nanoparticles are subject to dissociation phenomena. The dissociation rate was observed to follow Arrhenius behavior, and the Meyer–Neldel rule was obeyed. These results are useful in understanding the behavior of tungsten dust generatedmore » in nuclear fusion devices as well as for the preparation, formation, and application of tungsten powders.« less

DSMC study of oxygen shockwaves based on high-fidelity vibrational relaxation and dissociation models

NASA Astrophysics Data System (ADS)

Borges Sebastião, Israel; Kulakhmetov, Marat; Alexeenko, Alina

2017-01-01

This work evaluates high-fidelity vibrational-translational (VT) energy relaxation and dissociation models for pure O2 normal shockwave simulations with the direct simulation Monte Carlo (DSMC) method. The O2-O collisions are described using ab initio state-specific relaxation and dissociation models. The Macheret-Fridman (MF) dissociation model is adapted to the DSMC framework by modifying the standard implementation of the total collision energy (TCE) model. The O2-O2 dissociation is modeled with this TCE+MF approach, which is calibrated with O2-O ab initio data and experimental equilibrium dissociation rates. The O2-O2 vibrational relaxation is modeled via the Larsen-Borgnakke model, calibrated to experimental VT rates. All the present results are compared to experimental data and previous calculations available in the literature. It is found that, in general, the ab initio dissociation model is better than the TCE model at matching the shock experiments. Therefore, when available, efficient ab initio models are preferred over phenomenological models. We also show that the proposed TCE + MF formulation can be used to improve the standard TCE model results when ab initio data are not available or limited.

Subunit dissociation in fish hemoglobins.

PubMed

Edelstein, S J; McEwen, B; Gibson, Q H

1976-12-10

The tetramer-dimer dissociation equilibria (K 4,2) of several fish hemoglobins have been examined by sedimentation velocity measurements with a scanner-computer system for the ultracentrifuge and by flash photolysis measurements using rapid kinetic methods. Samples studied in detail included hemoglobins from a marine teleost, Brevoortia tyrannus (common name, menhaden); a fresh water teleost, Cyprinus carpio, (common name, carp); and an elasmobranch Prionace glauca (common name, blue shark). For all three species in the CO form at pH 7, in 0.1 M phosphate buffer, sedimentation coefficients of 4.3 S (typical of tetrameric hemoglobin) are observed in the micromolar concentration range. In contrast, mammalian hemoglobins dissociate appreciably to dimers under these conditions. The inability to detect dissociation in three fish hemoglobins at the lowest concentrations examined indicates that K 4,2 must have a value of 10(-8) M or less. In flash photolysis experiments on very dilute solutions in long path length cells, two kinetic components were detected with their proportions varying as expected for an equilibrium between tetramers (the slower component) and dimers (the faster component); values of K 4,2 for the three fish hemoglobins in the range 10(-9) to 10(-8) M were calculated from these data. Thus, the values of K 4,2 for liganded forms of the fish hemoglobins appear to be midway between the value for liganded human hemoglobin (K 4,2 approximately 10(-6) M) and unliganded human hemoglobin (K 4,2 approximately 10(-12) M). This conclusion is supported by measurements on solutions containing guanidine hydrochloride to enhance the degree of dissociation. All three fish hemoglobins are appreciably dissociated at guanidine concentrations of about 0.8 M, which is roughly midway between the guanidine concentrations needed to cause comparable dissociation of liganded human hemoglobin (about 0.4 M) and unliganded human hemoglobin (about 1.6 M). Kinetic measurements on solutions containing guanidine hydrochloride indicated that there are changes in both the absolute rates and the proportions of the fast and slow components, which along with other factors complicated the analysis of the data in terms of dissociation constants. Measurements were also made in solutions containing urea to promote dissociation, but with this agent very high concentrations (about 6 M) were required to give measureable dissociation and the fish hemoglobins were unstable under these conditions, with appreciable loss of absorbance spectra in both the sedimentation and kinetic experiments.

Solution and Gas-Phase H/D Exchange of Protein-Small-Molecule Complexes: Cex and Its Inhibitors

NASA Astrophysics Data System (ADS)

Kang, Yang; Terrier, Peran; Ding, Chuanfan; Douglas, D. J.

2012-01-01

The properties of noncovalent complexes of the enzyme exo-1,4-β-D-glycanase ("Cex") with three aza-sugar inhibitors, deoxynojirimycin (X2DNJ), isofagomine lactam (X2IL), and isofagomine (X2IF), have been studied with solution and gas-phase hydrogen deuterium exchange (H/Dx) and measurements of collision cross sections of gas-phase ions. In solution, complexes have lower H/Dx levels than free Cex because binding the inhibitors blocks some sites from H/Dx and reduces fluctuations of the protein. In mass spectra of complexes, abundant Cex ions are seen, which mostly are formed by dissociation of complexes in the ion sampling interface. Both complex ions and Cex ions formed from a solution containing complexes have lower cross sections than Cex ions from a solution of Cex alone. This suggests the Cex ions formed by dissociation "remember" their solution conformations. For a given charge, ions of the complexes have greater gas-phase H/Dx levels than ions of Cex. Unlike cross sections, H/Dx levels of the complexes do not correlate with the relative gas-phase binding strengths measured by MS/MS. Cex ions from solutions with or without inhibitors, which have different cross sections, show the same H/Dx level after 15 s, indicating the ions may fold or unfold on the seconds time scale of the H/Dx experiment. Thus, cross sections show that complexes have more compact conformations than free protein ions on the time scale of ca. 1 ms. The gas-phase H/Dx measurements show that at least some complexes retain different conformations from the Cex ions on a time scale of seconds.

Evaluating sensitivity of complex electrical methods for monitoring CO2 intrusion into a shallow groundwater system and associated geochemical transformations

NASA Astrophysics Data System (ADS)

Dafflon, B.; Wu, Y.; Hubbard, S. S.; Birkholzer, J. T.; Daley, T. M.; Pugh, J. D.; Peterson, J.; Trautz, R. C.

2011-12-01

A risk factor of CO2 storage in deep geological formations includes its potential to leak into shallow formations and impact groundwater geochemistry and quality. In particular, CO2 decreases groundwater pH, which can potentially mobilize naturally occurring trace metals and ions commonly absorbed to or contained in sediments. Here, geophysical studies (primarily complex electrical method) are being carried out at both laboratory and field scales to evaluate the sensitivity of geophysical methods for monitoring dissolved CO2 distribution and geochemical transformations that may impact water quality. Our research is performed in association with a field test that is exploring the effects of dissolved CO2 intrusion on groundwater geochemistry. Laboratory experiments using site sediments (silica sand and some fraction of clay minerals) and groundwater were initially conducted under field relevant CO2 partial pressures (pCO2). A significant pH drop was observed with inline sensors with concurrent changes in fluid conductivity caused by CO2 dissolution. Electrical resistivity and electrical phase responses correlated well with the CO2 dissolution process at various pCO2. Specifically, resistivity decreased initially at low pCO2 condition resulting from CO2 dissolution followed by a slight rebound because of the transition of bicarbonate into non-dissociated carbonic acid at lower pH slightly reducing the total concentration of dissociated species. Continuous electrical phase decreases were also observed, which are interpreted to be driven by the decrease of surface charge density (due to the decrease of pH, which approaches the PZC of the sediments). In general, laboratory experiments revealed the sensitivity of electrical signals to CO2 intrusion into groundwater formations and can be used to guide field data interpretation. Cross well complex electrical data are currently being collected periodically throughout a field experiment involving the controlled release of dissolved CO2 into groundwater. The objective of the geophysical cross well monitoring effort is to evaluate the sensitivity of complex electrical methods to dissolved CO2 at the field scale. Here, we report on the ability to translate laboratory-based petrophysical information from lab to field scales, and on the potential of field complex electrical methods for remotely monitoring CO2-induced geochemical transformations.

Dissociating movement from movement timing in the rat primary motor cortex.

PubMed

Knudsen, Eric B; Powers, Marissa E; Moxon, Karen A

2014-11-19

Neural encoding of the passage of time to produce temporally precise movements remains an open question. Neurons in several brain regions across different experimental contexts encode estimates of temporal intervals by scaling their activity in proportion to the interval duration. In motor cortex the degree to which this scaled activity relies upon afferent feedback and is guided by motor output remains unclear. Using a neural reward paradigm to dissociate neural activity from motor output before and after complete spinal transection, we show that temporally scaled activity occurs in the rat hindlimb motor cortex in the absence of motor output and after transection. Context-dependent changes in the encoding are plastic, reversible, and re-established following injury. Therefore, in the absence of motor output and despite a loss of afferent feedback, thought necessary for timed movements, the rat motor cortex displays scaled activity during a broad range of temporally demanding tasks similar to that identified in other brain regions. Copyright © 2014 the authors 0270-6474/14/3415576-11$15.00/0.

Dissociation, Trauma, and the Role of Lived Experience: Toward a New Conceptualization of Voice Hearing

ERIC Educational Resources Information Center

Longden, Eleanor; Madill, Anna; Waterman, Mitch G.

2012-01-01

Voice hearing (VH) is often regarded as pathognomic for schizophrenia. The purpose of this article is to review and integrate historical, clinical, epidemiological, and phenomenological evidence in order to suggest that VH may be more appropriately understood as a dissociative rather than a psychotic phenomenon. First, we discuss the lifetime…

A Survey Focusing on Lucid Dreaming, Metacognition, and Dream Anxiety in Medical Students

PubMed Central

YOKUŞOĞLU, Çağdaş; ATASOY, Mücahit; TEKELİ, Nurgül; URAL, Ahmet; ULUS, Çağla; TAYLAN, Yunus; AYDIN, Gülser; GÜLTEKİN, Gözde; EMÜL, Murat

2017-01-01

Introduction The aim of this study was to examine the level of lucidity and its relation with metacognitive beliefs and dream anxiety in medical students. Methods Nine hundred sixteen medical students were enrolled in the study. The participants were assessed with the Lucidity and Consciousness in Dreams Scale (LuCiD), the Metacognition Questionnaire-30 (MCQ-30), and the Van Dream Anxiety Scale (VDAS). Results There was no significant difference in mean total lucidity score between females and males, but there were some significant sex differences in subscales of lucidity, and control was significantly higher in male students, while realism, thought, and dissociation were significantly higher in female students. In addition, females had more dream anxiety levels, higher total MCQ-30 scores, and higher cognitive confidence and uncontrollability scores according to Metacognition Questionnaire-30 than males. We also found that the mean lucidity level was positively correlated with the mean total metacognition score and the mean total dream anxiety level. Discussion Our results suggest that female medical students tend to have more realistic dreams (p=0.018), have more logical thoughts during dreaming (p=0.011), and have a more dissociative experience during dreaming (p=0.028), while male medical students have more controlled dream events (p=0.002). There seem to be differences according to lucidity features between sexes, and the relationship between subdomains of lucidity and metacognition might lead to new therapeutic approaches to several psychiatric disorders such as anxiety disorders. PMID:29033639

Family risk factors and prevalence of dissociative symptoms among homeless and runaway youth.

PubMed

Tyler, Kimberly A; Cauce, Ana Mari; Whitbeck, Les

2004-03-01

To examine family risk factors associated with dissociative symptoms among homeless and runaway youth. Three hundred and twenty-eight homeless and runaway youth were interviewed using a systematic sampling strategy in metropolitan Seattle. Homeless young people were interviewed on the streets and in shelters by outreach workers in youth service agencies. The current study revealed widespread prevalence of dissociative symptoms among these young people. Multivariate analyses revealed that sexual abuse, physical abuse, and family mental health problems were all positively associated with dissociative symptoms. No gender differences were found for any of the models. Dissociative behavior is widespread among these youth and may pose a serious mental health concern. Some young people experience numerous stressors, and with few resources and little support available, many may invoke maladaptive strategies such as dissociative behavior to handle such situations, which may in turn be detrimental to their mental health. Unless youth are provided with programs and intervention, the cycle of abuse that they have experienced at home is likely to continue on the street.

Dissociative photoionization of isoprene: experiments and calculations.

PubMed

Liu, Xianyun; Zhang, Weijun; Wang, Zhenya; Huang, Mingqiang; Yang, Xibin; Tao, Ling; Sun, Yue; Xu, Yuntao; Shan, Xiaobin; Liu, Fuyi; Sheng, Liusi

2009-03-01

Vacuum ultraviolet (VUV) dissociative photoionization of isoprene in the energy region 8.5-18 eV was investigated with photoionization mass spectroscopy (PIMS) using synchrotron radiation (SR). The ionization energy (IE) of isoprene as well as the appearance energies (AEs) of its fragment ions C(5)H(7) (+), C(5)H(5) (+), C(4)H(5) (+), C(3)H(6) (+), C(3)H(5) (+), C(3)H(4) (+), C(3)H(3) (+) and C(2)H(3) (+) were determined with photoionization efficiency (PIE) curves. The dissociation energies of some possible dissociation channels to produce those fragment ions were also determined experimentally. The total energies of C(5)H(8) and its main fragments were calculated using the Gaussian 03 program and the Gaussian-2 method. The IE of C(5)H(8), the AEs for its fragment ions, and the dissociation energies to produce them were predicted using the high-accuracy energy model. According to our results, the experimental dissociation energies were in reasonable agreement with the calculated values of the proposed photodissociation channels of C(5)H(8). Copyright (c) 2009 John Wiley & Sons, Ltd.

Demonstrating the effects of phonological similarity and frequency on item and order memory in Down syndrome using process dissociation.

PubMed

Smith, Elizabeth; Jarrold, Christopher

2014-12-01

It is important to distinguish between memory for item information and memory for order information when considering the nature of verbal short-term memory (vSTM) performance. Although other researchers have attempted to make this distinction between item and order memory in children, none has done so using process dissociation. This study shows that such an approach can be particularly useful and informative. Individuals with Down syndrome (DS) tend to experience a vSTM deficit. These two experiments explored whether phonological similarity (Experiment 1) and item frequency (Experiment 2) affected vSTM for item and order information in a group of individuals with DS compared with typically developing (TD) vocabulary-matched children. Process dissociation was used to obtain measures of item and order memory via Nairne and Kelley's procedure (Journal of Memory and Language, 50 (2004) 113-133). Those with DS were poorer than the matched TD group for recall of both item and order information. However, in both populations, phonologically similar items reduced order memory but enhanced item memory, whereas high-frequency items resulted in improvements in both item and order memory-effects that are in line with previous research in the adult literature. These results indicate that, despite poorer vSTM performance in DS, individuals experience phonological coding of verbal input and a contribution of long-term memory knowledge to recall. These findings inform routes for interventions for those with DS, highlighting the need to enhance both item and order memory. Moreover, this work demonstrates that process dissociation is applicable and informative for studying special populations and children. Copyright © 2014 Elsevier Inc. All rights reserved.

A laboratory study on the dissociative recombination of vibrationally excited O2/+/ions

NASA Technical Reports Server (NTRS)

Zipf, E. C.

1980-01-01

The dissociative recombination of vibrationally excited O2(+) ions is studied in light of the possible importance of this reaction in upper atmospheric chemistry. A plasma spectroscopy experiment was performed in a microwave cavity filled by an argon-oxygen mixture, with O(1S) production monitored by measurements of the 5577-A afterglow, the O2(+) density and the electron concentration. Plasma and optical data reveal the predominant afterglow ions to be Ar2(+) and O2(+), with an effective O(1S) dissociative recombination coefficient of 2.1 x 10 to the -8th cu cm/sec, corresponding to a quantum yield of 10%. Experiments with an argon-krypton-oxygen mixture reveal that vibrationally excited O2(+) ions are the chief source of the O(1S) atoms, with a specific recombination coefficient for the dissociation of O2(+)(2 pi g) into O(1S) and O(1D) of 4.2 x 10 to the -9th cu cm/sec. A comparison of the laboratory results with Atmospheric Explorer data on the 5577-A airglow implies that O2(+) ions in the sunlit ionosphere are vibrationally excited to the same degree as in the laboratory, with the vibrational relaxation of these ions much slower than dissociative recombination. Results also predict a dawn-twilight asymmetry in the effective O(1S) yield due to the normal variation of electron content.

An evaluation of nonclinical dissociation utilizing a virtual environment shows enhanced working memory and attention.

PubMed

Saidel-Goley, Isaac N; Albiero, Erin E; Flannery, Kathleen A

2012-02-01

Dissociation is a mental process resulting in the disruption of memory, perception, and sometimes identity. At a nonclinical level, only mild dissociative experiences occur. The nature of nonclinical dissociation is disputed in the literature, with some asserting that it is a beneficial information processing style and others positing that it is a psychopathological phenomenon. The purpose of this study was to further the understanding of nonclinical dissociation with respect to memory and attention, by including a more ecologically valid virtual reality (VR) memory task along with standard neuropsychological tasks. Forty-five undergraduate students from a small liberal arts college in the northeast participated for course credit. The participants completed a battery of tasks including two standard memory tasks, a standard attention task, and an experimental VR memory task; the VR task included immersion in a virtual apartment, followed by incidental object-location recall for objects in the virtual apartment. Support for the theoretical model portraying nonclinical dissociation as a beneficial information processing style was found in this study. Dissociation scores were positively correlated with working memory scores and attentional processing scores on the standard neuropsychological tasks. In terms of the VR task, dissociation scores were positively correlated with more false positive memories that could be the result of a tendency of nonclinical highly dissociative individuals to create more elaborative schemas. This study also demonstrates that VR paradigms add to the prediction of cognitive functioning in testing protocols using standard neuropsychological tests, while simultaneously increasing ecological validity.

Dissociation of I II in chemical oxygen-iodine lasers: experiment, modeling, and pre-dissociation by electrical discharge

NASA Astrophysics Data System (ADS)

Katz, A.; Waichman, K.; Dahan, Z.; Rybalkin, V.; Barmashenko, B. D.; Rosenwaks, S.

2007-06-01

The dissociation of I II molecules at the optical axis of a supersonic chemical oxygen-iodine laser (COIL) was studied via detailed measurements and three dimensional computational fluid dynamics calculations. Comparing the measurements and the calculations enabled critical examination of previously proposed dissociation mechanisms and suggestion of a mechanism consistent with the experimental and theoretical results obtained in a supersonic COIL for the gain, temperature and I II dissociation fraction at the optical axis. The suggested mechanism combines the recent scheme of Azyazov and Heaven (AIAA J. 44, 1593 (2006)), where I II(A' 3Π 2u), I II(A 3Π 1u) and O II(a1Δ g, v) are significant dissociation intermediates, with the "standard" chain branching mechanism of Heidner et al. (J. Phys. Chem. 87, 2348 (1983)), involving I(2P 1/2) and I II(X1Σ + g, v). In addition, we examined a new method for enhancement of the gain and power in a COIL by applying DC corona/glow discharge in the transonic section of the secondary flow in the supersonic nozzle, dissociating I II prior to its mixing with O II(1Δ). The loss of O II(1Δ) consumed for dissociation was thus reduced and the consequent dissociation rate downstream of the discharge increased, resulting in up to 80% power enhancement. The implication of this method for COILs operating beyond the specific conditions reported here is assessed.

Magical flight and monstrous stress: technologies of absorption and mental wellness in Azeroth.

PubMed

Snodgrass, Jeffrey G; Lacy, Michael G; Francois Dengah, H J; Fagan, Jesse; Most, David E

2011-03-01

Videogame players commonly report reaching deeply "immersive" states of consciousness, in some cases growing to feel like they actually are their characters and really in the game, with such fantastic characters and places potentially only loosely connected to offline selves and realities. In the current investigation, we use interview and survey data to examine the effects of such "dissociative" experiences on players of the popular online videogame, World of Warcraft (WoW). Of particular interest are ways in which WoW players' emotional identification with in-game second selves can lead either to better mental well-being, through relaxation and satisfying positive stress, or, alternatively, to risky addiction-like experiences. Combining universalizing and context-dependent perspectives, we suggest that WoW and similar games can be thought of as new "technologies of absorption"--contemporary practices that can induce dissociative states in which players attribute dimensions of self and experience to in-game characters, with potential psychological benefit or harm. We present our research as an empirically grounded exploration of the mental health benefits and risks associated with dissociation in common everyday contexts. We believe that studies such as ours may enrich existing theories of the health dynamics of dissociation, relying, as they often do, on data drawn either from Western clinical contexts involving pathological disintegrated personality disorders or from non-Western ethnographic contexts involving spiritual trance.

Revealing Ligand Binding Sites and Quantifying Subunit Variants of Noncovalent Protein Complexes in a Single Native Top-Down FTICR MS Experiment

NASA Astrophysics Data System (ADS)

Li, Huilin; Wongkongkathep, Piriya; Van Orden, Steve L.; Ogorzalek Loo, Rachel R.; Loo, Joseph A.

2014-12-01

"Native" mass spectrometry (MS) has been proven to be increasingly useful for structural biology studies of macromolecular assemblies. Using horse liver alcohol dehydrogenase (hADH) and yeast alcohol dehydrogenase (yADH) as examples, we demonstrate that rich information can be obtained in a single native top-down MS experiment using Fourier transform ion cyclotron mass spectrometry (FTICR MS). Beyond measuring the molecular weights of the protein complexes, isotopic mass resolution was achieved for yeast ADH tetramer (147 kDa) with an average resolving power of 412,700 at m/z 5466 in absorption mode, and the mass reflects that each subunit binds to two zinc atoms. The N-terminal 89 amino acid residues were sequenced in a top-down electron capture dissociation (ECD) experiment, along with the identifications of the zinc binding site at Cys46 and a point mutation (V58T). With the combination of various activation/dissociation techniques, including ECD, in-source dissociation (ISD), collisionally activated dissociation (CAD), and infrared multiphoton dissociation (IRMPD), 40% of the yADH sequence was derived directly from the native tetramer complex. For hADH, native top-down ECD-MS shows that both E and S subunits are present in the hADH sample, with a relative ratio of 4:1. Native top-down ISD of the hADH dimer shows that each subunit (E and S chains) binds not only to two zinc atoms, but also the NAD/NADH ligand, with a higher NAD/NADH binding preference for the S chain relative to the E chain. In total, 32% sequence coverage was achieved for both E and S chains.

Free recall in Williams syndrome: is there a dissociation between short- and long-term memory?

PubMed

Brock, Jon; Brown, Gordon D A; Boucher, Jill

2006-04-01

Two experiments used the free recall paradigm to investigate verbal memory abilities in Williams syndrome (WS)--a rare genetic disorder. In an earlier free recall study, Vicari et al. (1996a) reported that, unlike TD controls, children with WS showed a recency effect but failed to show a primacy effect. These authors interpreted their findings as evidence for a dissociation between relatively strong verbal short-term memory and relatively impaired verbal long-term memory. In Experiment 1 of the current study, children with WS and TD controls showed comparable improvements in performance with repeated testing of the same material, indicating similar long-term learning of the test items. Neither group showed evidence of primacy effects. However, the extent of primacy effects in free recall is known to depend on the rehearsal strategy that participants adopt. In Experiment 2, therefore, participants were encouraged to engage in overt cumulative rehearsal. This manipulation resulted in significant and comparable primacy effects in both groups, although neither group demonstrated a significant change in overall performance. There was therefore no evidence from either experiment for a dissociation between short- and long-term verbal memory in WS.

Dissociations and dissociation theory in hypnosis: comment on Kirsch and Lynn (1998)

PubMed

Kihlstrom, J F

1998-03-01

I. Kirsch and S. J. Lynn's (1998) critique of the neodissociation theory of divided consciousness fails to consider evidence of dissociations between explicit and implicit memory and perception in hypnosis. Contrary to their conclusions, evidence that the rate of hidden observer response (like other hypnotic responses) varies with the wording of instructions does not contradict neodissociation theory; rather, it underscores the fact that hypnosis entails social interaction as well as alterations in conscious awareness. Neodissociation and sociocognitive theories of hypnosis complement each other. Each draws attention to aspects of the experience of hypnosis that the other neglects.

The dissociation mechanism and thermodynamic properties of HCl(aq) in hydrothermal fluids (to 700 °C, 60 kbar) by ab initio molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Mei, Yuan; Liu, Weihua; Brugger, Joël; Sherman, David M.; Gale, Julian D.

2018-04-01

HCl is one of the most significant volatiles in the Earth's crust. It is well established that chloride activity and acidity (pH) play important roles in controlling the solubility of metals in aqueous hydrothermal fluids. Thus, quantifying the dissociation of HCl in aqueous solutions over a wide range of temperature and pressure is crucial for the understanding and numerical modeling of element mobility in hydrothermal fluids. Here we have conducted ab initio molecular dynamics (MD) simulations to investigate the mechanism of HCl(aq) dissociation and to calculate the thermodynamic properties for the dissociation reaction at 25-700 °C, 1 bar to 60 kbar, i.e. including high temperature and pressure conditions that are geologically important, but difficult to investigate via experiments. Our results predict that HCl(aq) tends to associate with increasing temperature, and dissociate with increasing pressure. In particular, HCl(aq) is highly dissociated at extremely high pressures, even at high temperatures (e.g., 60 kbar, 600-700 °C). At 25 °C, the calculated logKd values (6.79 ± 0.81) are close to the value (7.0) recommended by IUPAC (International Union of Pure and Applied Chemistry) and some previous experimental and theoretical studies (Simonson et al.., 1990; Sulpizi and Sprik, 2008, 2010). The MD simulations indicate full dissociation of HCl at low temperature; in contrast, some experiments were interpreted assuming significant association at high HCl concentrations (≥1 m HCltot) even at room T (logKd ∼0.7; e.g., Ruaya and Seward, 1987; Sretenskaya, 1992; review in Tagirov et al., 1997). This discrepancy is most likely the result of difficulties in the experimental determination of minor (if any) concentration of associated HCl(aq) under ambient conditions, and thus reflects differences in the activity models used for the interpretation of the experiments. With increasing temperature, the discrepancy between our MD results and previous experimental studies, and between different studies, becomes smaller as the degree of HCl association increases. The MD simulations and available experimental studies show consistent results at hydrothermal conditions (300-700 °C, up to 5 kbar). The new thermodynamic properties based on the MD results provide an independent check of the dissociation constants for HCl(aq), and the first dataset on HCl dissociation in high P-T fluids (up to 60 kbar, 700 °C) beyond available experimental conditions. Our results will enable prediction of the role of HCl in controlling element mobility in deep earth hydrothermal systems, including fluids associated with ultra-high pressure metasomatism in subduction zones.

Implicit memory. Retention without remembering.

PubMed

Roediger, H L

1990-09-01

Explicit measures of human memory, such as recall or recognition, reflect conscious recollection of the past. Implicit tests of retention measure transfer (or priming) from past experience on tasks that do not require conscious recollection of recent experiences for their performance. The article reviews research on the relation between explicit and implicit memory. The evidence points to substantial differences between standard explicit and implicit tests, because many variables create dissociations between these tests. For example, although pictures are remembered better than words on explicit tests, words produce more priming than do pictures on several implicit tests. These dissociations may implicate different memory systems that subserve distinct memorial functions, but the present argument is that many dissociations can be understood by appealing to general principles that apply to both explicit and implicit tests. Phenomena studied under the rubric of implicit memory may have important implications in many other fields, including social cognition, problem solving, and cognitive development.

Simulation of field-induced molecular dissociation in atom-probe tomography: Identification of a neutral emission channel

NASA Astrophysics Data System (ADS)

Zanuttini, David; Blum, Ivan; Rigutti, Lorenzo; Vurpillot, François; Douady, Julie; Jacquet, Emmanuelle; Anglade, Pierre-Matthieu; Gervais, Benoit

2017-06-01

We investigate the dynamics of dicationic metal-oxide molecules under large electric-field conditions, on the basis of ab initio calculations coupled to molecular dynamics. Applied to the case of ZnO2 + in the field of atom probe tomography (APT), our simulation reveals the dissociation into three distinct exit channels. The proportions of these channels depend critically on the field strength and on the initial molecular orientation with respect to the field. For typical field strength used in APT experiments, an efficient dissociation channel leads to emission of neutral oxygen atoms, which escape detection. The calculated composition biases and their dependence on the field strength show remarkable consistency with recent APT experiments on ZnO crystals. Our work shows that bond breaking in strong static fields may lead to significant neutral atom production, and therefore to severe elemental composition biases in measurements.

Sound velocities in shocked liquid D2 to 28 GPa

NASA Astrophysics Data System (ADS)

Holmes, N. C.; Ross, M.; Nellis, W. J.

1999-06-01

Recent measurements of shock temperatures(N. C. Holmes, W. J. Nellis, and M. Ross, Phys. Rev.) B52, 15835 (1995). and laser-driven Hugoniot measurements(L. B. Da Silva, et al.), Phys. Rev. Lett. 78, 483 (1997). of shocked liquid deuterium strongly indicate that molecular dissociation is important above 20 GPa. Since the amount of expected dissociation is small on the Hugoniot at the 30 GPa limit of conventional impact experiments, other methods must be used to test our understanding of the physics of highly compressed deuterium in this regime. We have recently performed experiments to measure the sound velocity of deuterium which test the isentropic compressibility, c^2 = (partial P/partial ρ)_S. We used the shock overtake method to measure sound velocities at several shock pressures between 10--28 GPa. These data provide support for recently developed molecular dissociation models.

Human embryonic stem cell phosphoproteome revealed by electron transfer dissociation tandem mass spectrometry.

PubMed

Swaney, Danielle L; Wenger, Craig D; Thomson, James A; Coon, Joshua J

2009-01-27

Protein phosphorylation is central to the understanding of cellular signaling, and cellular signaling is suggested to play a major role in the regulation of human embryonic stem (ES) cell pluripotency. Here, we describe the use of conventional tandem mass spectrometry-based sequencing technology--collision-activated dissociation (CAD)--and the more recently developed method electron transfer dissociation (ETD) to characterize the human ES cell phosphoproteome. In total, these experiments resulted in the identification of 11,995 unique phosphopeptides, corresponding to 10,844 nonredundant phosphorylation sites, at a 1% false discovery rate (FDR). Among these phosphorylation sites are 5 localized to 2 pluripotency critical transcription factors--OCT4 and SOX2. From these experiments, we conclude that ETD identifies a larger number of unique phosphopeptides than CAD (8,087 to 3,868), more frequently localizes the phosphorylation site to a specific residue (49.8% compared with 29.6%), and sequences whole classes of phosphopeptides previously unobserved.

Evidence of automatic processing in sequence learning using process-dissociation

PubMed Central

Mong, Heather M.; McCabe, David P.; Clegg, Benjamin A.

2012-01-01

This paper proposes a way to apply process-dissociation to sequence learning in addition and extension to the approach used by Destrebecqz and Cleeremans (2001). Participants were trained on two sequences separated from each other by a short break. Following training, participants self-reported their knowledge of the sequences. A recognition test was then performed which required discrimination of two trained sequences, either under the instructions to call any sequence encountered in the experiment “old” (the inclusion condition), or only sequence fragments from one half of the experiment “old” (the exclusion condition). The recognition test elicited automatic and controlled process estimates using the process dissociation procedure, and suggested both processes were involved. Examining the underlying processes supporting performance may provide more information on the fundamental aspects of the implicit and explicit constructs than has been attainable through awareness testing. PMID:22679465

Characterization of a new qQq-FTICR mass spectrometer for post-translational modification analysis and top-down tandem mass spectrometry of whole proteins.

PubMed

Jebanathirajah, Judith A; Pittman, Jason L; Thomson, Bruce A; Budnik, Bogdan A; Kaur, Parminder; Rape, Michael; Kirschner, Marc; Costello, Catherine E; O'Connor, Peter B

2005-12-01

The use of a new electrospray qQq Fourier transform ion cyclotron mass spectrometer (qQq-FTICR MS) instrument for biologic applications is described. This qQq-FTICR mass spectrometer was designed for the study of post-translationally modified proteins and for top-down analysis of biologically relevant protein samples. The utility of the instrument for the analysis of phosphorylation, a common and important post-translational modification, was investigated. Phosphorylation was chosen as an example because it is ubiquitous and challenging to analyze. In addition, the use of the instrument for top-down sequencing of proteins was explored since this instrument offers particular advantages to this approach. Top-down sequencing was performed on different proteins, including commercially available proteins and biologically derived samples such as the human E2 ubiquitin conjugating enzyme, UbCH10. A good sequence tag was obtained for the human UbCH10, allowing the unambiguous identification of the protein. The instrument was built with a commercially produced front end: a focusing rf-only quadrupole (Q0), followed by a resolving quadrupole (Q1), and a LINAC quadrupole collision cell (Q2), in combination with an FTICR mass analyzer. It has utility in the analysis of samples found in substoichiometric concentrations, as ions can be isolated in the mass resolving Q1 and accumulated in Q2 before analysis in the ICR cell. The speed and efficacy of the Q2 cooling and fragmentation was demonstrated on an LCMS-compatible time scale, and detection limits for phosphopeptides in the 10 amol/muL range (pM) were demonstrated. The instrument was designed to make several fragmentation methods available, including nozzle-skimmer fragmentation, Q2 collisionally activated dissociation (Q2 CAD), multipole storage assisted dissociation (MSAD), electron capture dissociation (ECD), infrared multiphoton induced dissociation (IRMPD), and sustained off resonance irradiation (SORI) CAD, thus allowing a variety of MS(n) experiments. A particularly useful aspect of the system was the use of Q1 to isolate ions from complex mixtures with narrow windows of isolation less than 1 m/z. These features enable top-down protein analysis experiments as well structural characterization of minor components of complex mixtures.

Electron Localization in Dissociating H 2 + by Retroaction of a Photoelectron onto Its Source

DOE PAGES

Waitz, M.; Asliturk, D.; Wechselberger, N.; ...

2016-01-26

We investigate the dissociation of H 2 + into a proton and a H 0 after single ionization with photons of an energy close to the threshold. We find that the p + and the H 0 do not emerge symmetrically in the case of the H 2 + dissociating along the 1sσ g ground state. Instead, a preference for the ejection of the p + in the direction of the escaping photoelectron can be observed. This symmetry breaking is strongest for very small electron energies. Our experiment is consistent with a recent prediction by Serov and Kheifets. In theirmore » model, which treats the photoelectron classically, the symmetry breaking is induced by the retroaction of the long-range Coulomb potential onto the dissociating H 2 +.« less

Features of dissociation differentially predict antidepressant response to ketamine in treatment-resistant depression.

PubMed

Niciu, Mark J; Shovestul, Bridget J; Jaso, Brittany A; Farmer, Cristan; Luckenbaugh, David A; Brutsche, Nancy E; Park, Lawrence T; Ballard, Elizabeth D; Zarate, Carlos A

2018-05-01

Ketamine induces rapid and robust antidepressant effects, and many patients also describe dissociation, which is associated with antidepressant response. This follow-up study investigated whether antidepressant efficacy is uniquely related to dissociative symptom clusters. Treatment-resistant patients with major depressive disorder (MDD) or bipolar disorder (BD) (n = 126) drawn from three studies received a single subanesthetic (0.5 mg/kg) ketamine infusion. Dissociative effects were measured using the Clinician-Administered Dissociative States Scale (CADSS). Antidepressant response was measured using the 17-item Hamilton Depression Rating Scale (HAM-D). A confirmatory factor analysis established the validity of CADSS subscales (derealization, depersonalization, amnesia), and a general linear model with repeated measures was fitted to test whether subscale scores were associated with antidepressant response. Factor validity was supported, with a root mean square error of approximation of .06, a comparative fit index of .97, and a Tucker-Lewis index of .96. Across all studies and timepoints, the depersonalization subscale was positively related to HAM-D percent change. A significant effect of derealization on HAM-D percent change was observed at one timepoint (Day 7) in one study. The amnesia subscale was unrelated to HAM-D percent change. Possible inadequate blinding; combined MDD/BD datasets might have underrepresented ketamine's antidepressant efficacy; the possibility of Type I errors in secondary analyses. From a psychometric perspective, researchers may elect to administer only the CADSS depersonalization subscale, given that it was most closely related to antidepressant response. From a neurobiological perspective, mechanistic similarities may exist between ketamine-induced depersonalization and antidepressant response, although off-target effects cannot be excluded. Published by Elsevier B.V.

The production of O(1D) from dissociative recombination of O2(+)

NASA Technical Reports Server (NTRS)

Guberman, Steven L.

1988-01-01

The results of large scale ab initio calculations of the rates for production of O(1D) by dissociative combination of O2(+) are presented for electron temperatures in the range 100 to 3000 K. A 1-delta-u state is the dominant dissociative route from v = 0 and a 3-sigma-u(-) state is the most important route from v = 1 and v = 2. The calculated total rate for O(1D) production from v = 0 is 2.21(+0.21, -0.24) x 10(-7) x (T sub e/300) exp -.46 near room temperature. The v = 1 and v = 2 rates are about 17 percent and 47 percent smaller respectively, than the v = 0 rate at 300 K.

The production of O(1D) from dissociative recombination of O2(+)

NASA Technical Reports Server (NTRS)

Guberman, Steven L.

1987-01-01

The results of large scale ab initio calculations of the rates for production of O(1D) by dissociative combination of O2(+) are presented for electron temperatures in the range 100 to 3000 K. A 1-delta-u state is the dominant dissociative route from v = 0 and a 3-sigma-u(-) state is the most important route from v = 1 and v = 2. The calculated total rate for O(1D) production from v = 0 is 2.21(+0.21,-0.24) x 10(-7) x (T sub e/300) exp -.46 near room temperature. The v = 1 and v = 2 rates are about 17% and 47% smaller respectively, than the v = 0 rate at 300 K.

An automated exploration of the isomerization and dissociation pathways of (E)-1,2-dichloroethene cations and anions

NASA Astrophysics Data System (ADS)

Kishimoto, Naoki; Nishi, Yuito

2017-04-01

Isomerization and dissociation pathways after the photoionization or electron attachment of (E)-1,2-dichloroethene were calculated with an automated exploration method utilizing a scaled hypersphere search of the anharmonic downward distortion following algorithm at the UB3LYP/6-311G(2d,d,p) level of theory. The potential energies of transition states and dissociation channels were calculated by a composite method ((RO)CBS-QB3) and compared with the breakdown diagrams and electron attachment spectra observed in previous spectroscopic studies. The results of single point calculations with several DFT and post-SCF methods are compared using the root mean square deviations from the (RO)CBS-QB3 energies for six states of anionic dichloroethene.

Coupled channel effects on resonance states of positronic alkali atom

NASA Astrophysics Data System (ADS)

Yamashita, Takuma; Kino, Yasushi

2018-01-01

S-wave Feshbach resonance states belonging to dipole series in positronic alkali atoms (e+Li, e+Na, e+K, e+Rb and e+Cs) are studied by coupled-channel calculations within a three-body model. Resonance energies and widths below a dissociation threshold of alkali-ion and positronium are calculated with a complex scaling method. Extended model potentials that provide positronic pseudo-alkali-atoms are introduced to investigate the relationship between the resonance states and dissociation thresholds based on a three-body dynamics. Resonances of the dipole series below a dissociation threshold of alkali-atom and positron would have some associations with atomic energy levels that results in longer resonance lifetimes than the prediction of the analytical law derived from the ion-dipole interaction.

Treatment of a Patient with Borderline Personality Disorder Based on Phase-Oriented Model of Eye Movement Desensitization and Reprocessing (EMDR): A Case Report.

PubMed

Momeni Safarabad, Nahid; Asgharnejad Farid, Ali-Asghar; Gharraee, Banafsheh; Habibi, Mojtaba

2018-01-01

Objective: This study aimed at reporting the effect of the 3-phase model of eye movement desensitization and reprocessing in the treatment of a patient with borderline personality disorder. Method : A 33-year-old female, who met the DSM-IV-TR criteria for borderline personality disorder, received a 20-session therapy based on the 3-phase model of eye movement desensitization and reprocessing. Borderline Personality Disorder Checklist (BPD-Checklist), Dissociative Experience Scale (DES-II), Beck Depression Inventory-II-second edition (BDI-II), and Anxiety Inventory (BAI) were filled out by the patient at all treatment phases and at the 3- month follow- up. Results: According to the obtained results, the patient's pretest scores in all research tools were 161, 44, 37, and 38 for BPD-Checklist, DES-II, BDI-II, and BAI, respectively. After treatment, these scores decreased significantly (69, 14, 6 and 10 respectively). So, the patient exhibited improvement in borderline personality disorder, dissociative, depression and anxiety symptoms, which were maintained after the 3-month follow-up. Conclusion: The results supported the positive effect of phasic model of eye movement desensitization and reprocessing on borderline personality disorder.

Treatment of a Patient with Borderline Personality Disorder Based on Phase-Oriented Model of Eye Movement Desensitization and Reprocessing (EMDR): A Case Report

PubMed Central

Momeni Safarabad, Nahid; Asgharnejad Farid, Ali-Asghar; Gharraee, Banafsheh; Habibi, Mojtaba

2018-01-01

Objective: This study aimed at reporting the effect of the 3-phase model of eye movement desensitization and reprocessing in the treatment of a patient with borderline personality disorder. Method : A 33-year-old female, who met the DSM-IV-TR criteria for borderline personality disorder, received a 20-session therapy based on the 3-phase model of eye movement desensitization and reprocessing. Borderline Personality Disorder Checklist (BPD-Checklist), Dissociative Experience Scale (DES-II), Beck Depression Inventory-II-second edition (BDI-II), and Anxiety Inventory (BAI) were filled out by the patient at all treatment phases and at the 3- month follow- up. Results: According to the obtained results, the patient’s pretest scores in all research tools were 161, 44, 37, and 38 for BPD-Checklist, DES-II, BDI-II, and BAI, respectively. After treatment, these scores decreased significantly (69, 14, 6 and 10 respectively). So, the patient exhibited improvement in borderline personality disorder, dissociative, depression and anxiety symptoms, which were maintained after the 3-month follow-up. Conclusion: The results supported the positive effect of phasic model of eye movement desensitization and reprocessing on borderline personality disorder. PMID:29892320

Type and timing of childhood maltreatment and severity of shutdown dissociation in patients with schizophrenia spectrum disorder.

PubMed

Schalinski, Inga; Teicher, Martin H

2015-01-01

Dissociation, particularly the shutting down of sensory, motor and speech systems, has been proposed to emerge in susceptible individuals as a defensive response to traumatic stress. In contrast, other individuals show signs of hyperarousal to acute threat. A key question is whether exposure to particular types of stressful events during specific stages of development can program an individual to have a strong dissociative response to subsequent stressors. Vulnerability to ongoing shutdown dissociation was assessed in 75 inpatients (46 M/29 F, M = 31 ± 10 years old) with schizophrenia spectrum disorder and related to number of traumatic events experienced or witnessed during childhood or adulthood. The Maltreatment and Abuse Chronology of Exposure (MACE) scale was used to collect retrospective recall of exposure to ten types of maltreatment during each year of childhood. Severity of shutdown dissociation was related to number of childhood but not adult traumatic events. Random forest regression with conditional trees indicated that type and timing of childhood maltreatment could predictably account for 31% of the variance (p < 0.003) in shutdown dissociation, with peak vulnerability occurring at 13-14 years of age and with exposure to emotional neglect followed by various forms of emotional abuse. These findings suggest that there may be windows of vulnerability to the development of shutdown dissociation. Results support the hypothesis that experienced events are more important than witnessed events, but challenge the hypothesis that "life-threatening" events are a critical determinant.

Using Electrophoretic Mobility Shift Assays to Measure Equilibrium Dissociation Constants: GAL4-p53 Binding DNA as a Model System

ERIC Educational Resources Information Center

Heffler, Michael A.; Walters, Ryan D.; Kugel, Jennifer F.

2012-01-01

An undergraduate biochemistry laboratory experiment is described that will teach students the practical and theoretical considerations for measuring the equilibrium dissociation constant (K[subscript D]) for a protein/DNA interaction using electrophoretic mobility shift assays (EMSAs). An EMSA monitors the migration of DNA through a native gel;…

Dissociation in Middle Childhood among Foster Children with Early Maltreatment Experiences

ERIC Educational Resources Information Center

Hulette, Annmarie C.; Freyd, Jennifer J.; Fisher, Philip A.

2011-01-01

Objective: This study examined levels of dissociation in school-aged foster children who had been maltreated before age 5. Method: Data were collected from 118 children (age in years: M=9.34, SD=1.02) and their caregivers. Chi-Square and ANOVA were used to compare foster children (n=67) to community comparison children (n=51). Regression analyses…

Enhancing the intense field control of molecular fragmentation.

PubMed

Anis, Fatima; Esry, B D

2012-09-28

We describe a pump-probe scheme with which the spatial asymmetry of dissociating molecular fragments-as controlled by the carrier-envelope phase of an intense few-cycle laser pulse-can be enhanced by an order of magnitude or more. We illustrate the scheme using extensive, full-dimensional calculations for dissociation of H(2)(+) and include the averaging necessary for comparison with experiment.

Static and kinetic studies of calmodulin and melittin complex.

PubMed

Itakura, M; Iio, T

1992-08-01

Ca2+ binding to calmodulin triggers conformational change of the protein which induces exposure of hydrophobic surfaces. Melittin has been believed to bind to Ca(2+)-bound calmodulin through the exposed hydrophobic surfaces. However, tryptophan fluorescence measurements and gel chromatography experiments with the melittin-calmodulin system revealed that melittin bound to calmodulin at zero salt concentration even in the absence of Ca2+; addition of salt removed melittin from Ca(2+)-free calmodulin. This means not only the hydrophobic interaction but also the electrostatic interaction contributes to the melittin-calmodulin binding. The fluorescence stopped-flow studies of the dissociation reaction of melittin-calmodulin complex revealed that Ca2+ removal from the complex induced a conformational change of calmodulin, resulting in reduction of the hydrophobic interaction between melittin and calmodulin, but the electrostatic interaction kept melittin still bound to calmodulin for a subsecond lag period, after which melittin dissociated from calmodulin. The fluorescence stopped-flow experiments on the dissociation reaction of complex of melittin and tryptic fragment(s) of calmodulin revealed that the lag period of the melittin dissociation reaction was attributable to the interaction between the C-terminal half of calmodulin and the C-terminal region of melittin.

Directed-Backbone Dissociation Following Bond-Specific Carbon-Sulfur UVPD at 213 nm

NASA Astrophysics Data System (ADS)

Talbert, Lance E.; Julian, Ryan R.

2018-04-01

Ultraviolet photodissociation or UVPD is an increasingly popular option for tandem-mass spectrometry experiments. UVPD can be carried out at many wavelengths, and it is important to understand how the results will be impacted by this choice. Here, we explore the utility of 213 nm photons for initiating bond-selective fragmentation. It is found that bonds previously determined to be labile at 266 nm, including carbon-iodine and sulfur-sulfur bonds, can also be cleaved with high selectivity at 213 nm. In addition, many carbon-sulfur bonds that are not subject to direct dissociation at 266 nm can be selectively fragmented at 213 nm. This capability can be used to site-specifically create alaninyl radicals that direct backbone dissociation at the radical site, creating diagnostic d-ions. Furthermore, the additional carbon-sulfur bond fragmentation capability leads to signature triplets for fragmentation of disulfide bonds. Absorption of amide bonds can enhance dissociation of nearby labile carbon-sulfur bonds and can be used for stochastic backbone fragmentation typical of UVPD experiments at shorter wavelengths. Several potential applications of the bond-selective fragmentation chemistry observed at 213 nm are discussed. [Figure not available: see fulltext.

Peritraumatic dissociation predicts posttraumatic stress disorder symptoms via dysfunctional trauma-related memory among war-affected children.

PubMed

Peltonen, Kirsi; Kangaslampi, Samuli; Saranpää, Jenni; Qouta, Samir; Punamäki, Raija-Leena

2017-01-01

Background : Among adults there is strong evidence about peritraumatic dissociation (PD) predicting posttraumatic stress disorder (PTSD), yet evidence among children is very limited. It has been suggested that disturbances in memory functioning might explain the association between PD and PTSD, but this has not yet been empirically tested. Objective : We aimed to test the hypotheses that greater PD would be associated with more posttraumatic stress disorder (PTSD) symptoms, and that some of this association would be mediated by disorganized and non-verbal memories about the traumatic event. Method : The sample included 197 Palestinian children (10-12-years) living in the Gaza Strip, participating in the aftermath of the 2008/9 war. Self-report questionnaires were used to measure PD (Peritraumatic Dissociative Experiences Questionnaire) three months post-war, as well as trauma-related memory (Trauma Memory Quality Questionnaire) and PTSD symptoms (Children's Revised Impact of Event Scale) six months later. Exposure to war trauma was assessed by a checklist. Structural equation modelling was used to examine direct and indirect paths from PD to posttraumatic PTSS, controlling for number of traumatic war events. Results : Structural equation modelling results showed that greater self-reported PD predicted higher levels of PTSS nine months post-war, and that a significant part, but not all, of this relationship was mediated via the quality of trauma-related memories. Conclusions : This study provided empirical evidence that, among war-affected children, greater PD during traumatic events is linked with higher levels of PTSD symptoms several months later, even when accounting for their personal exposure to war trauma. Further, the study supported the idea that the detrimental effects of dissociation during a traumatic event may be due to dysfunctional memories characterized by disorganization and lack of access to verbal and coherence. Further tests of these hypotheses with larger samples and more points of measurement are called for.

Hydrolysis at One of the Two Nucleotide-binding Sites Drives the Dissociation of ATP-binding Cassette Nucleotide-binding Domain Dimers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zoghbi, M. E.; Altenberg, G. A.

The functional unit of ATP-binding cassette (ABC) transporters consists of two transmembrane domains and two nucleotide-binding domains (NBDs). ATP binding elicits association of the two NBDs, forming a dimer in a head-to-tail arrangement, with two nucleotides “sandwiched” at the dimer interface. Each of the two nucleotide-binding sites is formed by residues from the two NBDs. We recently found that the prototypical NBD MJ0796 from Methanocaldococcus jannaschii dimerizes in response to ATP binding and dissociates completely following ATP hydrolysis. However, it is still unknown whether dissociation of NBD dimers follows ATP hydrolysis at one or both nucleotide-binding sites. Here, we usedmore » luminescence resonance energy transfer to study heterodimers formed by one active (donor-labeled) and one catalytically defective (acceptor-labeled) NBD. Rapid mixing experiments in a stop-flow chamber showed that NBD heterodimers with one functional and one inactive site dissociated at a rate indistinguishable from that of dimers with two hydrolysis-competent sites. Comparison of the rates of NBD dimer dissociation and ATP hydrolysis indicated that dissociation followed hydrolysis of one ATP. We conclude that ATP hydrolysis at one nucleotide-binding site drives NBD dimer dissociation.« less

Dissociative symptoms mediate the relation between PTSD symptoms and functional impairment in a sample of military members, veterans, and first responders with PTSD.

PubMed

Boyd, Jenna E; Protopopescu, Alina; O'Connor, Charlene; Neufeld, Richard W J; Jetly, Rakesh; Hood, Heather K; Lanius, Ruth A; McKinnon, Margaret C

2018-01-01

Background : Posttraumatic Stress Disorder (PTSD) is associated with significant functional impairment in important areas, including interpersonal relationships and occupational or educational roles. Preliminary evidence suggests that the dissociative subtype of PTSD (PTSD+DS), characterized by marked symptoms of depersonalization and derealization, is associated with increased functional impairment and disease severity, including among military members and veterans diagnosed with PTSD. Similarly, first responders (e.g. police, fire, paramedics) have also been found to experience dissociative symptoms. Despite these findings, little work has investigated whether dissociative symptoms are related to heightened functional impairment among these populations. Objective : We examined the relation between functional impairment and symptom level variables, including dissociative symptoms of depersonalization and derealization among military members, veterans, and first responders with probable PTSD. We further investigated the hypothesis that dissociative symptoms mediate the relation between PTSD symptomatology and functional impairment. Method : Eighty-one medical charts of inpatients at a residential PTSD treatment programme were accessed via retrospective review. Sixty-two were included in the present analyses. Comparison of means on symptom measures between first responders and military members/veterans were conducted, followed by correlational and mediation analyses. Results : Compared with first responders, military members and veterans showed higher levels of derealization, functional impairment, alexithymia, anxiety, and depression. Within the total sample, dissociative symptoms emerged as the strongest correlate of functional impairment and, among the dissociative symptom clusters, derealization symptoms demonstrated the strongest relation with impairment. Mediation analyses revealed that total dissociative symptoms and derealization symptoms significantly mediated the relation between PTSD symptoms and functional impairment. Conclusions : These findings highlight the importance of assessing and treating dissociative symptoms, consistent with the dissociative subtype of PTSD, among military members, veterans, and first responders with PTSD. Successful recovery on a functional and symptomatic level may necessitate treatment of dissociative symptoms, particularly derealization.

Dissociative symptoms mediate the relation between PTSD symptoms and functional impairment in a sample of military members, veterans, and first responders with PTSD

PubMed Central

Protopopescu, Alina; O’Connor, Charlene; Neufeld, Richard W. J.; Jetly, Rakesh; Hood, Heather K.; Lanius, Ruth A.; McKinnon, Margaret C.

2018-01-01

ABSTRACT Background: Posttraumatic Stress Disorder (PTSD) is associated with significant functional impairment in important areas, including interpersonal relationships and occupational or educational roles. Preliminary evidence suggests that the dissociative subtype of PTSD (PTSD+DS), characterized by marked symptoms of depersonalization and derealization, is associated with increased functional impairment and disease severity, including among military members and veterans diagnosed with PTSD. Similarly, first responders (e.g. police, fire, paramedics) have also been found to experience dissociative symptoms. Despite these findings, little work has investigated whether dissociative symptoms are related to heightened functional impairment among these populations. Objective: We examined the relation between functional impairment and symptom level variables, including dissociative symptoms of depersonalization and derealization among military members, veterans, and first responders with probable PTSD. We further investigated the hypothesis that dissociative symptoms mediate the relation between PTSD symptomatology and functional impairment. Method: Eighty-one medical charts of inpatients at a residential PTSD treatment programme were accessed via retrospective review. Sixty-two were included in the present analyses. Comparison of means on symptom measures between first responders and military members/veterans were conducted, followed by correlational and mediation analyses. Results: Compared with first responders, military members and veterans showed higher levels of derealization, functional impairment, alexithymia, anxiety, and depression. Within the total sample, dissociative symptoms emerged as the strongest correlate of functional impairment and, among the dissociative symptom clusters, derealization symptoms demonstrated the strongest relation with impairment. Mediation analyses revealed that total dissociative symptoms and derealization symptoms significantly mediated the relation between PTSD symptoms and functional impairment. Conclusions: These findings highlight the importance of assessing and treating dissociative symptoms, consistent with the dissociative subtype of PTSD, among military members, veterans, and first responders with PTSD. Successful recovery on a functional and symptomatic level may necessitate treatment of dissociative symptoms, particularly derealization. PMID:29805778

Dissociative electron attachment to the radiosensitizing chemotherapeutic agent hydroxyurea

NASA Astrophysics Data System (ADS)

Huber, S. E.; Śmiałek, M. A.; Tanzer, K.; Denifl, S.

2016-06-01

Dissociative electron attachment to hydroxyurea was studied in the gas phase for electron energies ranging from zero to 9 eV in order to probe its radiosensitizing capabilities. The experiments were carried out using a hemispherical electron monochromator coupled with a quadrupole mass spectrometer. Diversified fragmentation of hydroxyurea was observed upon low energy electron attachment and here we highlight the major dissociation channels. Moreover, thermodynamic thresholds for various fragmentation reactions are reported to support the discussion of the experimental findings. The dominant dissociation channel, which was observed over a broad range of energies, is associated with formation of NCO-, water, and the amidogen (NH2) radical. The second and third most dominant dissociation channels are associated with formation of NCNH- and NHCONH2-, respectively, which are both directly related to formation of the highly reactive hydroxyl radical. Other ions observed with significant abundance in the mass spectra were NH2-/O-, OH-, CN-, HNOH-, NCONH2-, and ONHCONH2-.

Deconstructing DID.

PubMed

Brenner, I

1999-01-01

The author contends that a psychoanalytically informed approach to the patient with dissociative identity disorder (DID) can be very useful. However, there are difficulties in conceptualizing this condition without extending existing theory or applying in new ways what is already known. It is also difficult to put DID in a proper context relative to all the other disorders known to occur in the human mind. Depending on one's clinical experience, level of skepticism, and appreciation of history, DID may be seen as either: a) the psychological "missing link" that realizes Freud's goal of uniting the psychology of dreams with psychopathology, or b) a fraudulent condition that is wittingly or unwittingly manufactured in the therapist's office or c) a population of disturbed and disturbing patients, once the subject of great scientific interest, which, exiled like a "Lost Tribe," is now back in the fold of legitimacy. The author has had extensive clinical experience with psychic trauma, and bases his own views of DID on three assumptions: 1. that dissociation may be seen as a complex defense; 2. that DID may be thought of as a "lower level dissociative character"; and 3. that there is a unique psychic structure, the "dissociative self" whose function is to create "alter personalities" out of disowned affects, memories, fantasies, and drives. This "dissociative self" must be dissolved in order for integration of "alter personalities" to occur. A clinical vignette is offered to illustrate how he addresses some of the challenges of developing a therapeutic alliance at this end of the dissociative-character-pathology continuum, and how he grapples with the difficulty of integrating clinical phenomena, such as the appearance of "alters," with the psychoanalytic model of the mind.

Sequencing Larger Intact Proteins (30-70 kDa) with Activated Ion Electron Transfer Dissociation

NASA Astrophysics Data System (ADS)

Riley, Nicholas M.; Westphall, Michael S.; Coon, Joshua J.

2018-01-01

The analysis of intact proteins via mass spectrometry can offer several benefits to proteome characterization, although the majority of top-down experiments focus on proteoforms in a relatively low mass range (<30 kDa). Recent studies have focused on improving the analysis of larger intact proteins (up to 75 kDa), but they have also highlighted several challenges to be addressed. One major hurdle is the efficient dissociation of larger protein ions, which often to do not yield extensive fragmentation via conventional tandem MS methods. Here we describe the first application of activated ion electron transfer dissociation (AI-ETD) to proteins in the 30-70 kDa range. AI-ETD leverages infrared photo-activation concurrent to ETD reactions to improve sequence-informative product ion generation. This method generates more product ions and greater sequence coverage than conventional ETD, higher-energy collisional dissociation (HCD), and ETD combined with supplemental HCD activation (EThcD). Importantly, AI-ETD provides the most thorough protein characterization for every precursor ion charge state investigated in this study, making it suitable as a universal fragmentation method in top-down experiments. Additionally, we highlight several acquisition strategies that can benefit characterization of larger proteins with AI-ETD, including combination of spectra from multiple ETD reaction times for a given precursor ion, multiple spectral acquisitions of the same precursor ion, and combination of spectra from two different dissociation methods (e.g., AI-ETD and HCD). In all, AI-ETD shows great promise as a method for dissociating larger intact protein ions as top-down proteomics continues to advance into larger mass ranges. [Figure not available: see fulltext.

Fragmentation of relativistic nuclei in peripheral interactions in nuclear track emulsion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Artemenkov, D. A., E-mail: artemenkov@lhe.jinr.ru; Bradnova, V.; Chernyavsky, M. M.

2008-09-15

The technique of nuclear track emulsions is used to explore the fragmentation of light relativistic nuclei down to the most peripheral interactions: nuclear 'white' stars. A complete pattern of the relativistic dissociation of a 8B nucleus with target fragment accompaniment is presented. Relativistic dissociation {sup 9}Be {yields} 2{alpha} is explored using significant statistics, and a relative contribution of {sup 8}Be decays from 0+ and 2+ states is established. Target fragment accompaniments are shown for relativistic fragmentation {sup 14}N {yields} 3He +H and {sup 22}Ne {yields} 5He. The leading role of the electromagnetic dissociation on heavy nuclei with respect to breakupsmore » on target protons is demonstrated in all these cases. It is possible to conclude that the peripheral dissociation of relativistic nuclei in nuclear track emulsion is a unique tool to study many-body systems composed of the lightest nuclei and nucleons in the energy scale relevant for nuclear astrophysics.« less

Symboldrama, a psychotherapeutic method for adolescents with dissociative and PTSD symptoms: a pilot study.

PubMed

Nilsson, Doris; Wadsby, Marie

2010-01-01

A total of 15 clinically referred adolescents who had been sexually or physically abused participated in this pilot study of the use of symboldrama psychotherapy. Symboldrama is a psychotherapeutic method that uses imagery as the major psychotherapeutic tool. All adolescents reported to be suffering from a high level of dissociative symptoms and other symptoms such as anxiety, depression, posttraumatic stress, and anger after their traumas. The objective of the study was to test the hypothesis that symboldrama psychotherapy in addition to psycho-education of the non-offending parent would significantly reduce the reported symptoms. Before treatment, the participants answered three questionnaires: (a) the Life Incidence of Traumatic Events Scale, (b) the Trauma Symptom Checklist for Children, and (c) the Dissociation Questionnaire-Swedish version. After treatment, the participants once again filled out the Trauma Symptom Checklist for Children and the Dissociation Questionnaire-Swedish version. The scores from before and after treatment were compared, and the results showed that the symptoms had been statistically significantly reduced.

A cGMP-applicable expansion method for aggregates of human neural stem and progenitor cells derived from pluripotent stem cells or fetal brain tissue.

PubMed

Shelley, Brandon C; Gowing, Geneviève; Svendsen, Clive N

2014-06-15

A cell expansion technique to amass large numbers of cells from a single specimen for research experiments and clinical trials would greatly benefit the stem cell community. Many current expansion methods are laborious and costly, and those involving complete dissociation may cause several stem and progenitor cell types to undergo differentiation or early senescence. To overcome these problems, we have developed an automated mechanical passaging method referred to as "chopping" that is simple and inexpensive. This technique avoids chemical or enzymatic dissociation into single cells and instead allows for the large-scale expansion of suspended, spheroid cultures that maintain constant cell/cell contact. The chopping method has primarily been used for fetal brain-derived neural progenitor cells or neurospheres, and has recently been published for use with neural stem cells derived from embryonic and induced pluripotent stem cells. The procedure involves seeding neurospheres onto a tissue culture Petri dish and subsequently passing a sharp, sterile blade through the cells effectively automating the tedious process of manually mechanically dissociating each sphere. Suspending cells in culture provides a favorable surface area-to-volume ratio; as over 500,000 cells can be grown within a single neurosphere of less than 0.5 mm in diameter. In one T175 flask, over 50 million cells can grow in suspension cultures compared to only 15 million in adherent cultures. Importantly, the chopping procedure has been used under current good manufacturing practice (cGMP), permitting mass quantity production of clinical-grade cell products.

Optimization of high grade glioma cell culture from surgical specimens for use in clinically relevant animal models and 3D immunochemistry.

PubMed

Hasselbach, Laura A; Irtenkauf, Susan M; Lemke, Nancy W; Nelson, Kevin K; Berezovsky, Artem D; Carlton, Enoch T; Transou, Andrea D; Mikkelsen, Tom; deCarvalho, Ana C

2014-01-07

Glioblastomas, the most common and aggressive form of astrocytoma, are refractory to therapy, and molecularly heterogeneous. The ability to establish cell cultures that preserve the genomic profile of the parental tumors, for use in patient specific in vitro and in vivo models, has the potential to revolutionize the preclinical development of new treatments for glioblastoma tailored to the molecular characteristics of each tumor. Starting with fresh high grade astrocytoma tumors dissociated into single cells, we use the neurosphere assay as an enrichment method for cells presenting cancer stem cell phenotype, including expression of neural stem cell markers, long term self-renewal in vitro, and the ability to form orthotopic xenograft tumors. This method has been previously proposed, and is now in use by several investigators. Based on our experience of dissociating and culturing 125 glioblastoma specimens, we arrived at the detailed protocol we present here, suitable for routine neurosphere culturing of high grade astrocytomas and large scale expansion of tumorigenic cells for preclinical studies. We report on the efficiency of successful long term cultures using this protocol and suggest affordable alternatives for culturing dissociated glioblastoma cells that fail to grow as neurospheres. We also describe in detail a protocol for preserving the neurospheres 3D architecture for immunohistochemistry. Cell cultures enriched in CSCs, capable of generating orthotopic xenograft models that preserve the molecular signatures and heterogeneity of GBMs, are becoming increasingly popular for the study of the biology of GBMs and for the improved design of preclinical testing of potential therapies.

Optimization of High Grade Glioma Cell Culture from Surgical Specimens for Use in Clinically Relevant Animal Models and 3D Immunochemistry

PubMed Central

Hasselbach, Laura A.; Irtenkauf, Susan M.; Lemke, Nancy W.; Nelson, Kevin K.; Berezovsky, Artem D.; Carlton, Enoch T.; Transou, Andrea D.; Mikkelsen, Tom; deCarvalho, Ana C.

2014-01-01

Glioblastomas, the most common and aggressive form of astrocytoma, are refractory to therapy, and molecularly heterogeneous. The ability to establish cell cultures that preserve the genomic profile of the parental tumors, for use in patient specific in vitro and in vivo models, has the potential to revolutionize the preclinical development of new treatments for glioblastoma tailored to the molecular characteristics of each tumor. Starting with fresh high grade astrocytoma tumors dissociated into single cells, we use the neurosphere assay as an enrichment method for cells presenting cancer stem cell phenotype, including expression of neural stem cell markers, long term self-renewal in vitro, and the ability to form orthotopic xenograft tumors. This method has been previously proposed, and is now in use by several investigators. Based on our experience of dissociating and culturing 125 glioblastoma specimens, we arrived at the detailed protocol we present here, suitable for routine neurosphere culturing of high grade astrocytomas and large scale expansion of tumorigenic cells for preclinical studies. We report on the efficiency of successful long term cultures using this protocol and suggest affordable alternatives for culturing dissociated glioblastoma cells that fail to grow as neurospheres. We also describe in detail a protocol for preserving the neurospheres 3D architecture for immunohistochemistry. Cell cultures enriched in CSCs, capable of generating orthotopic xenograft models that preserve the molecular signatures and heterogeneity of GBMs, are becoming increasingly popular for the study of the biology of GBMs and for the improved design of preclinical testing of potential therapies. PMID:24429465

Dissociative disorders among adults in the community, impaired functioning, and axis I and II comorbidity.

PubMed

Johnson, Jeffrey G; Cohen, Patricia; Kasen, Stephanie; Brook, Judith S

2006-03-01

To investigate the association of dissociative disorder (DD) with impaired functioning and co-occurring Axis I and personality disorders among adults in the community. Psychiatric interviews were administered to a sample of 658 adult participants in the Children in the Community Study, a community-based longitudinal study. Depersonalization disorder (prevalence: 0.8%), dissociative amnesia (prevalence: 1.8%), dissociative identity disorder (prevalence: 1.5%), and dissociative disorder not otherwise specified (prevalence: 4.4%), evident within the past year, were each associated with impaired functioning, as assessed by the clinician-administered Global Assessment of Functioning Scale. These associations remained significant after controlling for age, sex, and co-occurring disorders. Individuals with anxiety, mood, and personality disorders were significantly more likely than individuals without these disorders were to have DD, after the covariates were controlled. Individuals with Cluster A (DD prevalence: 58%), B (DD prevalence: 68%), and C (DD prevalence: 37%) personality disorders were substantially more likely than those without personality disorders were to have DD. DD is associated with clinically significant impairment among adults in the community. DD may be particularly prevalent among individuals with personality disorders.

MMPI-2 Item Endorsements in Dissociative Identity Disorder vs. Simulators.

PubMed

Brand, Bethany L; Chasson, Gregory S; Palermo, Cori A; Donato, Frank M; Rhodes, Kyle P; Voorhees, Emily F

2016-03-01

Elevated scores on some MMPI-2 (Minnesota Multiphasic Inventory-2) validity scales are common among patients with dissociative identity disorder (DID), which raises questions about the validity of their responses. Such patients show elevated scores on atypical answers (F), F-psychopathology (Fp), atypical answers in the second half of the test (FB), schizophrenia (Sc), and depression (D) scales, with Fp showing the greatest utility in distinguishing them from coached and uncoached DID simulators. In the current study, we investigated the items on the MMPI-2 F, Fp, FB, Sc, and D scales that were most and least commonly endorsed by participants with DID in our 2014 study and compared these responses with those of coached and uncoached DID simulators. The comparisons revealed that patients with DID most frequently endorsed items related to dissociation, trauma, depression, fearfulness, conflict within family, and self-destructiveness. The coached group more successfully imitated item endorsements of the DID group than did the uncoached group. However, both simulating groups, especially the uncoached group, frequently endorsed items that were uncommonly endorsed by the DID group. The uncoached group endorsed items consistent with popular media portrayals of people with DID being violent, delusional, and unlawful. These results suggest that item endorsement patterns can provide useful information to clinicians making determinations about whether an individual is presenting with DID or feigning. © 2016 American Academy of Psychiatry and the Law.

Psychometric properties of the Spanish version of the Experiencing of Self Scale (EOSS) for assessment in Functional Analytic Psychotherapy.

PubMed

Valero-Aguayo, Luis; Ferro-García, Rafael; López-Bermúdez, Miguel Ángel; Selva-López de Huralde, María de los Ángeles

2014-01-01

The Experiencing of Self Scale (EOSS) was created to evaluate the experience of the personal self, within the field of Functional Analytic Psychotherapy. This paper presents a study of the reliability and validity of the EOSS in a Spanish sample. The study sample, chosen from 24 different centres, comprised 1,040 participants aged between 18-75, of whom 32% were men and 68% women. The clinical sample was made up of 32.7%, whereas 67.3% had no known problem. To obtain evidence of convergent validity, other questionnaires related to the self (EPQ-R, DES, RSES) were used for comparison. The EOSS showed high internal consistency (Cronbach's α = .941) and significantly high correlations with the EPQ-R Neuroticism scale and the DES Dissociation scale, while showing negative correlations with the Rosenberg Self-Esteem Scale (RSES). The EOSS revealed 4 principal factors: a self in close relationships, a self with casual social relationships, a self in general and a positive self-concept. Significant statistical differences were found between the clinical and standard sample, the former showing a higher average. The EOSS had high internal consistency, showing evidence of convergent validity with similar scales and proving useful for the assessment of people with psychological problems related to the self.

Observing electron localization in a dissociating H2+ molecule in real time

PubMed Central

Xu, H.; Li, Zhichao; He, Feng; Wang, X.; Atia-Tul-Noor, A.; Kielpinski, D.; Sang, R. T.; Litvinyuk, I. V.

2017-01-01

Dissociation of diatomic molecules with odd number of electrons always causes the unpaired electron to localize on one of the two resulting atomic fragments. In the simplest diatomic molecule H2+ dissociation yields a hydrogen atom and a proton with the sole electron ending up on one of the two nuclei. That is equivalent to breaking of a chemical bond—the most fundamental chemical process. Here we observe such electron localization in real time by performing a pump–probe experiment. We demonstrate that in H2+ electron localization is complete in just 15 fs when the molecule’s internuclear distance reaches 8 atomic units. The measurement is supported by a theoretical simulation based on numerical solution of the time-dependent Schrödinger equation. This observation advances our understanding of detailed dynamics of molecular dissociation. PMID:28621332

Dissociation and identity transformation in female survivors of the genocide against the Tutsi in Rwanda: a qualitative research study.

PubMed

Sandole, Denise H; Auerbach, Carl F

2013-01-01

This qualitative research study deals with female survivors of the 1994 genocide against the Tutsi in Rwanda. It examines dissociation and identity change in these women before, during, and after the genocide. Three theories were used to frame the findings. The 1st was assumptive world theory ( R. Janoff-Bulman, 1992 ), which postulates that traumatic events may shatter people's everyday assumptions about the world. The 2nd was catastrophic dissociation theory ( G. Boulanger, 2007 ), which refers to the gradual breakdown of the self as it repeatedly "experiences its psychic foundations in ways that do not happen in the average expectable life" (G. Boulanger, 2008 ,p. 646). The 3rd was structural dissociation theory ( O. Van der Hart, E. R. S. Nijenhuis, & K. Steele, 2006 ), which postulates that when people encounter events that they cannot integrate into their mental lives, their personality may fragment and divide. The data were transcripts of interviews with 30 female genocide survivors. Data analysis revealed that these women experienced trauma-induced identity transformations. Before the genocide, they existed as a "Civilized Self," with a stable identity in a secure, assumptive world. During the genocide, they existed as a "Survivor Self," the massive trauma of the genocide having disrupted their prior self-experience and identity. After the genocide, they existed as an "Aftermath Self," in which their Civilized and Survivor Selves coexisted in an unintegrated, dissociated form.

[Low dose naltrexone in the treatment of dissociative symptoms].

PubMed

Pape, W; Wöller, W

2015-03-01

Following the hypothesis that blocking opioid receptors leads to a decline in opiate-modulated dissociative phenomena, experiences with naltrexone as medication for dissociative symptoms have been gained since 1999 (mainly in doses of 25-100 mg/day). In this study patients with severe trauma-related and dissociative disorders were treated with naltrexone in doses of 2-6 mg/day (0.06 mg/kg body weight). The low dose treatment with naltrexone proved to be effective whereby 11 out of 15 patients reported immediate positive effects and 7 described a lasting helpful effect. The majority of patients who felt positive effects reported a clearer perception of both their surroundings and their inner life. Assessment of reality and dealing with it improved as did the perception of their own body and affects as well as self-regulation. The treatment was very low in side effects. Treatment with low-dose naltrexone may be a helpful element in the treatment of patients with complex posttraumatic stress disorder. However, it has to be realized that the decrease of dissociation may lead patients to a not yet resolvable challenge, in as much as dissociation had previously been a necessary mechanism of self-protection.

Disorganized attachment in young adulthood as a partial mediator of relations between severity of childhood abuse and dissociation.

PubMed

Byun, Sooyeon; Brumariu, Laura E; Lyons-Ruth, Karlen

2016-01-01

Disorganized attachment has been proposed as a mediating mechanism in the relation between childhood abuse and dissociation. However, support for mediation has been mixed when interview or self-report measures of attachment have been used. In the current work, relations among severity of abuse, attachment disorganization, and dissociation were assessed in young adulthood using both interview and interaction-based measures of attachment. A total of 112 low-income young adults were assessed for socioeconomic stresses, abusive experiences in childhood, and attachment disorganization at age 20. Attachment disorganization was assessed with the Adult Attachment Interview, coded independently for Unresolved states of mind and for Hostile-Helpless states of mind. Attachment disorganization was also measured using a newly validated assessment of young adult-parent interaction during a conflict discussion. Mediation analyses revealed that the link between childhood abuse and dissociation was partially explained by disturbances in young adult-parent interaction. Narrative disturbances on the Adult Attachment Interview were related to abuse and to dissociation but did not mediate the link between the two. Results are discussed in relation to the role of parent-child communication processes in pathways to dissociation.

The possessions at Loudun: tracking the discourse of dissociation.

PubMed

Stephenson, Craig E

2017-09-01

Embedded in the history of dissociation is the best known case of possession in European history, the 17 th century possessions at Loudun, France (1632-1638). The exorcisms and the trial drew crowds from all over Europe, the outcome prefiguring the direction in which the Western science of mind would be carried. The published debate about the possessed and obsessed Ursuline nuns of Loudun spans four centuries. One can track how theorizing about dissociation changed over time, with psychological contributions by Jean Martin Charcot, Georges Gilles de la Tourette, Pierre Janet, Michel Foucault and Michel de Certeau. Freud's psychoanalytic notion of demonological neurosis emphasized defensive strategies and a diabolic parody of adulthood. Jung's concepts of demonism and possession highlighted dissociated complexes that assimilate the ego and unseat the self, rendering a life 'provisional'. Dissociation as possession provides a through-line in Jung's Collected Works, from his 1902 dissertation to one of the last essays he wrote, in 1961. Within the context of psychotherapy, therapists and patients work towards psychological containment, consciously reorienting themselves to the presence of unconscious factors, personifying, embodying and thereby incorporating images of dissociated Otherness into the experience of selfhood. © 2017, The Society of Analytical Psychology.

Determining the partial photoionization cross-sections of ethyl radicals.

PubMed

FitzPatrick, B L; Maienschein-Cline, M; Butler, L J; Lee, S-H; Lin, J J

2007-12-13

Using a crossed laser-molecular beam scattering apparatus, these experiments photodissociate ethyl chloride at 193 nm and detect the Cl and ethyl products, resolved by their center-of-mass recoil velocities, with vacuum ultraviolet photoionization. The data determine the relative partial cross-sections for the photoionization of ethyl radicals to form C2H5+, C2H4+, and C2H3+ at 12.1 and 13.8 eV. The data also determine the internal energy distribution of the ethyl radical prior to photoionization, so we can assess the internal energy dependence of the photoionization cross-sections. The results show that the C2H4++H and C2H3++H2 dissociative photoionization cross-sections strongly depend on the photoionization energy. Calibrating the ethyl radical partial photoionization cross-sections relative to the bandwidth-averaged photoionization cross-section of Cl atoms near 13.8 eV allows us to use these data in conjunction with literature estimates of the Cl atom photoionization cross-sections to put the present bandwidth-averaged cross-sections on an absolute scale. The resulting bandwidth-averaged cross-section for the photoionization of ethyl radicals to C2H5+ near 13.8 eV is 8+/-2 Mb. Comparison of our 12.1 eV data with high-resolution ethyl radical photoionization spectra allows us to roughly put the high-resolution spectrum on the same absolute scale. Thus, one obtains the photoionization cross-section of ethyl radicals to C2H5+ from threshold to 12.1 eV. The data show that the onset of the C2H4++H dissociative photoionization channel is above 12.1 eV; this result offers a simple way to determine whether the signal observed in photoionization experiments on complex mixtures is due to ethyl radicals. We discuss an application of the results for resolving the product branching in the O+allyl bimolecular reaction.

Dynamics of dissociative electron attachment to ammonia

DOE PAGES

Rescigno, T. N.; Trevisan, C. S.; Orel, A. E.; ...

2016-05-12

We present that ab initio theoretical studies and momentum-imaging experiments are combined to provide a consistent picture of the dynamics of dissociative electron attachment to ammonia through its 5.5- and 10.5-eV resonance channels. The present study clarifies the character and symmetry of the anion states involved and the dynamics that leads to the observed fragment-ion channels, their branching ratios, and angular distributions.

Dynamics of dissociative electron attachment to ammonia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rescigno, T. N.; Trevisan, C. S.; Orel, A. E.

We present that ab initio theoretical studies and momentum-imaging experiments are combined to provide a consistent picture of the dynamics of dissociative electron attachment to ammonia through its 5.5- and 10.5-eV resonance channels. The present study clarifies the character and symmetry of the anion states involved and the dynamics that leads to the observed fragment-ion channels, their branching ratios, and angular distributions.

The Bond Dissociation Energies of 1-Butene

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Langhoff, Stephen R. (Technical Monitor)

1994-01-01

The bond dissociation energies of 1-butene and several calibration systems are computed using the G2(MP2) approach. The agreement between the calibration systems and experiment is very good. The computed values for 1-butene are compared with calibration systems and the agreement between the computed results for 1-butene and the "rule of thumb" values from the smaller systems is remarkably good.

Communication: Energy transfer and reaction dynamics for DCl scattering on Au(111): An ab initio molecular dynamics study.

PubMed

Kolb, Brian; Guo, Hua

2016-07-07

Scattering and dissociative chemisorption of DCl on Au(111) are investigated using ab initio molecular dynamics with a slab model, in which the top two layers of Au are mobile. Substantial kinetic energy loss in the scattered DCl is found, but the amount of energy transfer is notably smaller than that observed in the experiment. On the other hand, the dissociative chemisorption probability reproduces the experimental trend with respect to the initial kinetic energy, but is about one order of magnitude larger than the reported initial sticking probability. While the theory-experiment agreement is significantly improved from the previous rigid surface model, the remaining discrepancies are still substantial, calling for further scrutiny in both theory and experiment.

California Psychological Inventory Dominance Scale Measurement Equivalence: General Population Normative and Indian, U.K., and U.S. Managerial Samples

ERIC Educational Resources Information Center

Kulas, John T.; Thompson, Richard C.; Anderson, Michael G.

2011-01-01

The California Psychological Inventory's Dominance scale was investigated for inconsistencies in item-trait associations across four samples (one American normative and three culturally dissociated manager groupings). The Kim, Cohen, and Park procedure was used, enabling simultaneous multigroup comparison in addition to the traditional…

Unconscious gender bias in fame judgments?

PubMed

Buchner, A; Wippich, W

1996-01-01

In two experiments the conditions of, and the processes leading to, gender biases in fame judgments were investigated. In Experiment 1, the gender bias was not reduced in a condition that alerted participants to the gender of the names. In Experiment 2, participants' sex-role orientation, but not their gender, was related to the gender bias. The process dissociation procedure was used in both experiments in an attempt to separate conscious and unconscious memory processes contributing to the gender bias. Using L.L. Jacoby's 1991) original measurement model there appeared to be evidence for unconscious influences on the gender bias in fame judgments. Unfortunately, this evidence disappeared when a model was used that takes guessing and, hence, response biases into account, which confirms that measurement models that ignore response biases in the process dissociation procedure may lead to erroneous conclusions.

Investigating the thermal dissociation of viral capsid by lattice model

NASA Astrophysics Data System (ADS)

Chen, Jingzhi; Chevreuil, Maelenn; Combet, Sophie; Lansac, Yves; Tresset, Guillaume

2017-11-01

The dissociation of icosahedral viral capsids was investigated by a homogeneous and a heterogeneous lattice model. In thermal dissociation experiments with cowpea chlorotic mottle virus and probed by small-angle neutron scattering, we observed a slight shrinkage of viral capsids, which can be related to the strengthening of the hydrophobic interaction between subunits at increasing temperature. By considering the temperature dependence of hydrophobic interaction in the homogeneous lattice model, we were able to give a better estimate of the effective charge. In the heterogeneous lattice model, two sets of lattice sites represented different capsid subunits with asymmetric interaction strengths. In that case, the dissociation of capsids was found to shift from a sharp one-step transition to a gradual two-step transition by weakening the hydrophobic interaction between AB and CC subunits. We anticipate that such lattice models will shed further light on the statistical mechanics underlying virus assembly and disassembly.

Dissociation in virtual reality: depersonalization and derealization

NASA Astrophysics Data System (ADS)

Garvey, Gregory P.

2010-01-01

This paper looks at virtual worlds such as Second Life7 (SL) as possible incubators of dissociation disorders as classified by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition3 (also known as the DSM-IV). Depersonalization is where "a person feels that he or she has changed in some way or is somehow unreal." Derealization when "the same beliefs are held about one's surroundings." Dissociative Identity Disorder (DID), previously known as multiple personality disorder fits users of Second Life who adopt "in-world" avatars and in effect, enact multiple distinct identities or personalities (known as alter egos or alters). Select questions from the Structured Clinical Interview for Depersonalization (SCI-DER)8 will be discussed as they might apply to the user's experience in Second Life. Finally I would like to consider the hypothesis that rather than a pathological disorder, dissociation is a normal response to the "artificial reality" of Second Life.

The Dissociation between Polarity, Semantic Orientation, and Emotional Tone as an Early Indicator of Cognitive Impairment.

PubMed

Arias Tapia, Susana A; Martínez-Tomás, Rafael; Gómez, Héctor F; Hernández Del Salto, Víctor; Sánchez Guerrero, Javier; Mocha-Bonilla, J A; Barbosa Corbacho, José; Khan, Azizudin; Chicaiza Redin, Veronica

2016-01-01

The present study aims to identify early cognitive impairment through the efficient use of therapies that can improve the quality of daily life and prevent disease progress. We propose a methodology based on the hypothesis that the dissociation between oral semantic expression and the physical expressions, facial gestures, or emotions transmitted in a person's tone of voice is a possible indicator of cognitive impairment. Experiments were carried out with phrases, analyzing the semantics of the message, and the tone of the voice of patients through unstructured interviews in healthy people and patients at an early Alzheimer's stage. The results show that the dissociation in cognitive impairment was an effective indicator, arising from patterns of inconsistency between the analyzed elements. Although the results of our study are encouraging, we believe that further studies are necessary to confirm that this dissociation is a probable indicator of cognitive impairment.

The Dissociation between Polarity, Semantic Orientation, and Emotional Tone as an Early Indicator of Cognitive Impairment

PubMed Central

Arias Tapia, Susana A.; Martínez-Tomás, Rafael; Gómez, Héctor F.; Hernández del Salto, Víctor; Sánchez Guerrero, Javier; Mocha-Bonilla, J. A.; Barbosa Corbacho, José; Khan, Azizudin; Chicaiza Redin, Veronica

2016-01-01

The present study aims to identify early cognitive impairment through the efficient use of therapies that can improve the quality of daily life and prevent disease progress. We propose a methodology based on the hypothesis that the dissociation between oral semantic expression and the physical expressions, facial gestures, or emotions transmitted in a person's tone of voice is a possible indicator of cognitive impairment. Experiments were carried out with phrases, analyzing the semantics of the message, and the tone of the voice of patients through unstructured interviews in healthy people and patients at an early Alzheimer's stage. The results show that the dissociation in cognitive impairment was an effective indicator, arising from patterns of inconsistency between the analyzed elements. Although the results of our study are encouraging, we believe that further studies are necessary to confirm that this dissociation is a probable indicator of cognitive impairment. PMID:27683555

Dynamics of light-field control of molecular dissociation at the few-cycle limit.

PubMed

Tong, X M; Lin, C D

2007-03-23

We studied the laser-molecule interaction dynamics that leads to the asymmetric D+ ion ejection in the dissociative ionization of D2 molecules observed recently in Kling et al. [Science 312, 246 (2006)10.1126/science.1126259]. By changing the carrier-envelope phase, we showed that the asymmetry is a consequence of manipulating the initial ionization and the rescattering of the electrons within one optical cycle of the laser. The result illustrates the feasibility of coherent control of reaction dynamics at the attosecond time scale.

Repetition priming influences distinct brain systems: evidence from task-evoked data and resting-state correlations.

PubMed

Wig, Gagan S; Buckner, Randy L; Schacter, Daniel L

2009-05-01

Behavioral dissociations suggest that a single experience can separately influence multiple processing components. Here we used a repetition priming functional magnetic resonance imaging paradigm that directly contrasted the effects of stimulus and decision changes to identify the underlying brain systems. Direct repetition of stimulus features caused marked reductions in posterior regions of the inferior temporal lobe that were insensitive to whether the decision was held constant or changed between study and test. By contrast, prefrontal cortex showed repetition effects that were sensitive to the exact stimulus-to-decision mapping. Analysis of resting-state functional connectivity revealed that the dissociated repetition effects are embedded within distinct brain systems. Regions that were sensitive to changes in the stimulus correlated with perceptual cortices, whereas the decision changes attenuated activity in regions correlated with middle-temporal regions and a frontoparietal control system. These results thus explain the long-known dissociation between perceptual and conceptual components of priming by revealing how a single experience can separately influence distinct, concurrently active brain systems.

Implementation of a vibrationally linked chemical reaction model for DSMC

NASA Technical Reports Server (NTRS)

Carlson, A. B.; Bird, Graeme A.

1994-01-01

A new procedure closely linking dissociation and exchange reactions in air to the vibrational levels of the diatomic molecules has been implemented in both one- and two-dimensional versions of Direct Simulation Monte Carlo (DSMC) programs. The previous modeling of chemical reactions with DSMC was based on the continuum reaction rates for the various possible reactions. The new method is more closely related to the actual physics of dissociation and is more appropriate to the particle nature of DSMC. Two cases are presented: the relaxation to equilibrium of undissociated air initially at 10,000 K, and the axisymmetric calculation of shuttle forebody heating during reentry at 92.35 km and 7500 m/s. Although reaction rates are not used in determining the dissociations or exchange reactions, the new method produces rates which agree astonishingly well with the published rates derived from experiment. The results for gas properties and surface properties also agree well with the results produced by earlier DSMC models, equilibrium air calculations, and experiment.

Human embryonic stem cell phosphoproteome revealed by electron transfer dissociation tandem mass spectrometry

PubMed Central

Swaney, Danielle L.; Wenger, Craig D.; Thomson, James A.; Coon, Joshua J.

2009-01-01

Protein phosphorylation is central to the understanding of cellular signaling, and cellular signaling is suggested to play a major role in the regulation of human embryonic stem (ES) cell pluripotency. Here, we describe the use of conventional tandem mass spectrometry-based sequencing technology—collision-activated dissociation (CAD)—and the more recently developed method electron transfer dissociation (ETD) to characterize the human ES cell phosphoproteome. In total, these experiments resulted in the identification of 11,995 unique phosphopeptides, corresponding to 10,844 nonredundant phosphorylation sites, at a 1% false discovery rate (FDR). Among these phosphorylation sites are 5 localized to 2 pluripotency critical transcription factors—OCT4 and SOX2. From these experiments, we conclude that ETD identifies a larger number of unique phosphopeptides than CAD (8,087 to 3,868), more frequently localizes the phosphorylation site to a specific residue (49.8% compared with 29.6%), and sequences whole classes of phosphopeptides previously unobserved. PMID:19144917

Do recent observations of very large electromagnetic dissociation cross sections signify a transition towards non-perturbative QED?

NASA Technical Reports Server (NTRS)

Norbury, John W.

1992-01-01

The very large electromagnetic dissociation (EMD) cross section recently observed by Hill, Wohn, Schwellenbach, and Smith do not agree with Weizsacker-Williams (WW) theory or any simple modification thereof. Calculations are presented for the reaction probabilities for this experiment and the entire single and double nucleon removal EMD data set. It is found that for those few reactions where theory and experiment disagree, the probabilities are exceptionally large. This indicates that WW theory is not valid for these reactions and that one must consider higher order corrections and perhaps even a non-perturbative approach to quantum electrodynamics (QED).

Revisiting Fromm's passions as presaging contemporary views of affect and dissociation.

PubMed

Harrell, Valentina

2002-01-01

Fromm viewed intrapsychic dynamic processes as having their origin in a generalized organic life force that gets transformed into psychic energy called passions. He is acknowledged as one of the most original, creative writers of the mid-20th century whose fertile mind and humanistic sensibilities synthesized the domains of psychoanalysis, social philosophy, and politics. His unyielding belief that the development of the individual psyche is inseparable from its two-way interaction with a lived relational and cultural context presaged the evolution of the relational perspective in psychoanalysis, and his concept of passions foreshadowed contemporary neuroscientific theories of affect and its role in intrapsychic life and self-identity formation. Damasio's theory of emotions is reviewed as a specific example of the current revamping of psychoanalytic theory as bottom-up information processing, that is, the integrating and synthesizing of affective experience and memory (preverbal mentalization) as fueling the creation of a narrative self. Fromm's discussions of dissociation are linked both to Damasio's core self experiences and to Bromberg's conceptualization of psychoanalysis of dissociative experience as a process of "standing in the spaces." And finally, Fromm's descriptions of psychoanalysis as an art are linked to Schon's action-oriented theory of practical knowledge.

Activation of Peptide ions by blackbody radiation: factors that lead to dissociation kinetics in the rapid energy exchange limit.

PubMed

Price, W D; Williams, E R

1997-11-20

Unimolecular rate constants for blackbody infrared radiative dissociation (BIRD) were calculated for the model protonated peptide (AlaGly)(n) (n = 2-32) using a variety of dissociation parameters. Combinations of dissociation threshold energies ranging from 0.8 to 1.7 eV and transition entropies corresponding to Arrhenius preexponential factors ranging from very "tight" (A(infinity) = 10(9.9) s(-1)) to "loose" (A(infinity) = 10(16.8) s(-1)) were selected to represent dissociation parameters within the experimental temperature range (300-520 K) and kinetic window (k(uni) = 0.001-0.20 s(-1)) typically used in the BIRD experiment. Arrhenius parameters were determined from the temperature dependence of these values and compared to those in the rapid energy exchange (REX) limit. In this limit, the internal energy of a population of ions is given by a Boltzmann distribution, and kinetics are the same as those in the traditional high-pressure limit. For a dissociation process to be in this limit, the rate of photon exchange between an ion and the vacuum chamber walls must be significantly greater than the dissociation rate. Kinetics rapidly approach the REX limit either as the molecular size or threshold dissociation energy increases or as the transition-state entropy or experimental temperature decreases. Under typical experimental conditions, peptide ions larger than 1.6 kDa should be in the REX limit. Smaller ions may also be in the REX limit depending on the value of the threshold dissociation energy and transition-state entropy. Either modeling or information about the dissociation mechanism must be known in order to confirm REX limit kinetics for these smaller ions. Three principal factors that lead to the size dependence of REX limit kinetics are identified. With increasing molecular size, rates of radiative absorption and emission increase, internal energy distributions become relatively narrower, and the microcanonical dissociation rate constants increase more slowly over the energy distribution of ions. Guidelines established here should make BIRD an even more reliable method to obtain information about dissociation energetics and mechanisms for intermediate size molecules.

Activation of Peptide Ions by Blackbody Radiation: Factors That Lead to Dissociation Kinetics in the Rapid Energy Exchange Limit

PubMed Central

Price, William D.

2005-01-01

Unimolecular rate constants for blackbody infrared radiative dissociation (BIRD) were calculated for the model protonated peptide (AlaGly)n (n = 2–32) using a variety of dissociation parameters. Combinations of dissociation threshold energies ranging from 0.8 to 1.7 eV and transition entropies corresponding to Arrhenius preexponential factors ranging from very “tight” (A∞ = 109.9 s−1) to “loose” (A∞ = 1016.8 s−1) were selected to represent dissociation parameters within the experimental temperature range (300–520 K) and kinetic window (kuni = 0.001–0.20 s−1) typically used in the BIRD experiment. Arrhenius parameters were determined from the temperature dependence of these values and compared to those in the rapid energy exchange (REX) limit. In this limit, the internal energy of a population of ions is given by a Boltzmann distribution, and kinetics are the same as those in the traditional high-pressure limit. For a dissociation process to be in this limit, the rate of photon exchange between an ion and the vacuum chamber walls must be significantly greater than the dissociation rate. Kinetics rapidly approach the REX limit either as the molecular size or threshold dissociation energy increases or as the transition-state entropy or experimental temperature decreases. Under typical experimental conditions, peptide ions larger than 1.6 kDa should be in the REX limit. Smaller ions may also be in the REX limit depending on the value of the threshold dissociation energy and transition-state entropy. Either modeling or information about the dissociation mechanism must be known in order to confirm REX limit kinetics for these smaller ions. Three principal factors that lead to the size dependence of REX limit kinetics are identified. With increasing molecular size, rates of radiative absorption and emission increase, internal energy distributions become relatively narrower, and the microcanonical dissociation rate constants increase more slowly over the energy distribution of ions. Guidelines established here should make BIRD an even more reliable method to obtain information about dissociation energetics and mechanisms for intermediate size molecules. PMID:16604162

The enemy in the mirror: self-perception-induced stress results in dissociation of psychological and physiological responses in patients with dissociative disorder

PubMed Central

Sattel, Heribert; Schmidt, Ulrike; Sack, Martin

2018-01-01

ABSTRACT Background: Patients suffering from dissociative disorders (DD) are characterized by an avoidance of aversive stimuli. Clinical experience has shown that DD patients typically avoid the confrontation with their own faces in a mirror (CFM). Objective: To investigate potential CFM-associated self-reported and psychophysiological stress reactions of DD patients, which most likely inform on the still unknown pathophysiology of dysfunctional self-perception in DD. Method: Eighteen DD patients and 18 healthy controls (HCs) underwent CFM. They were assessed for CFM-induced subjective self-reported stress, acute dissociative symptoms and sympathetic and parasympathetic drive using impedance cardiography. Results: DD patients experienced more subjective stress and acute dissociation than HCs upon CFM. Their psychological stress response did not activate the sympathetic and parasympathetic nervous system. Conclusions: In DD patients, CFM constitutes serious self-reported stress and is associated with a blunted autonomic reactivity. Therapeutic approaches promoting self-perception and self-compassion, in particular by using CFM, might serve as goal-oriented diagnostic and therapeutic tools in DD.

The enemy in the mirror: self-perception-induced stress results in dissociation of psychological and physiological responses in patients with dissociative disorder.

PubMed

Schäflein, Eva; Sattel, Heribert; Schmidt, Ulrike; Sack, Martin

2018-01-01

Background : Patients suffering from dissociative disorders (DD) are characterized by an avoidance of aversive stimuli. Clinical experience has shown that DD patients typically avoid the confrontation with their own faces in a mirror (CFM). Objective : To investigate potential CFM-associated self-reported and psychophysiological stress reactions of DD patients, which most likely inform on the still unknown pathophysiology of dysfunctional self-perception in DD. Method : Eighteen DD patients and 18 healthy controls (HCs) underwent CFM. They were assessed for CFM-induced subjective self-reported stress, acute dissociative symptoms and sympathetic and parasympathetic drive using impedance cardiography. Results : DD patients experienced more subjective stress and acute dissociation than HCs upon CFM. Their psychological stress response did not activate the sympathetic and parasympathetic nervous system. Conclusions : In DD patients, CFM constitutes serious self-reported stress and is associated with a blunted autonomic reactivity. Therapeutic approaches promoting self-perception and self-compassion, in particular by using CFM, might serve as goal-oriented diagnostic and therapeutic tools in DD.

Dissociative electron attachment to the radiosensitizing chemotherapeutic agent hydroxyurea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huber, S. E.; Tanzer, K.; Denifl, S.

Dissociative electron attachment to hydroxyurea was studied in the gas phase for electron energies ranging from zero to 9 eV in order to probe its radiosensitizing capabilities. The experiments were carried out using a hemispherical electron monochromator coupled with a quadrupole mass spectrometer. Diversified fragmentation of hydroxyurea was observed upon low energy electron attachment and here we highlight the major dissociation channels. Moreover, thermodynamic thresholds for various fragmentation reactions are reported to support the discussion of the experimental findings. The dominant dissociation channel, which was observed over a broad range of energies, is associated with formation of NCO{sup −}, water,more » and the amidogen (NH{sub 2}) radical. The second and third most dominant dissociation channels are associated with formation of NCNH{sup −} and NHCONH{sub 2}{sup −}, respectively, which are both directly related to formation of the highly reactive hydroxyl radical. Other ions observed with significant abundance in the mass spectra were NH{sub 2}{sup −}/O{sup −}, OH{sup −}, CN{sup −}, HNOH{sup −}, NCONH{sub 2}{sup −}, and ONHCONH{sub 2}{sup −}.« less

Experiments with "Calo-ph Meter."

ERIC Educational Resources Information Center

Paris, Michel R.; Aymes, Daniel J.

1990-01-01

The principles and procedures for three enthalpimetric measurement experiments including a determination of the water equivalent mass of the calorimeter, the calibration of the instrument, and determination of the dissociation heat of boric acid performed with a teacher-made instrument are presented. Suggestions for further experiments are…

Reduced amygdala reactivity and impaired working memory during dissociation in borderline personality disorder.

PubMed

Krause-Utz, Annegret; Winter, Dorina; Schriner, Friederike; Chiu, Chui-De; Lis, Stefanie; Spinhoven, Philip; Bohus, Martin; Schmahl, Christian; Elzinga, Bernet M

2018-06-01

Affective hyper-reactivity and impaired cognitive control of emotional material are core features of borderline personality disorder (BPD). A high percentage of individuals with BPD experience stress-related dissociation, including emotional numbing and memory disruptions. So far little is known about how dissociation influences the neural processing of emotional material in the context of a working memory task in BPD. We aimed to investigate whole-brain activity and amygdala functional connectivity (FC) during an Emotional Working Memory Task (EWMT) after dissociation induction in un-medicated BPD patients compared to healthy controls (HC). Using script-driven imagery, dissociation was induced in 17 patients ('BPD_D'), while 12 patients ('BPD_N') and 18 HC were exposed to neutral scripts during fMRI. Afterwards, participants performed the EWMT with neutral vs. negative IAPS pictures vs. no distractors. Main outcome measures were behavioral performance (reaction times, errors) and whole-brain activity during the EWMT. Psychophysiological interaction analysis was used to examine amygdala connectivity during emotional distraction. BPD patients after dissociation induction showed overall WM impairments, a deactivation in bilateral amygdala, and lower activity in left cuneus, lingual gyrus, and posterior cingulate than BPD_N, along with stronger left inferior frontal gyrus activity than HC. Furthermore, reduced amygdala FC with fusiform gyrus and stronger amygdala FC with right middle/superior temporal gyrus and left inferior parietal lobule was observed in BPD_D. Findings suggest that dissociation affects reactivity to emotionally salient material and WM. Altered activity in areas associated with emotion processing, memory, and self-referential processes may contribute to dissociative states in BPD.

Memory for murder. A psychological perspective on dissociative amnesia in legal contexts.

PubMed

Porter, S; Birt, A R; Yuille, J C; Hervé, H F

2001-01-01

There is currently a complex and inconsistent state in the law relating to dissociation and dissociative amnesia (McSherry, 1998). Although dissociative amnesia in defendants is relevant to both competency to stand trial and criminal responsibility in principle, courts have typically assumed a skeptical stance toward such claims in practice. However, there is considerable evidence from both nonoffender and offender populations to support the validity of dissociative amnesia in defendants. Further, there is information available to aid in the evaluation of amnesia, such as the quality of the report itself and characteristics of the person reporting the amnesia (e.g., psychopathy). When consideration is given to the legal response to reports of dissociative amnesia by complainants, the situation becomes even more complex. While some courts have rejected recovered memory evidence, others have convicted defendants of historical offenses based on such evidence. In some cases, judges have argued that jurors should be left to decide on the validity of recovered memories based on their common sense and experience. The uncritical acceptance of the validity of repressed memories in complainants by many courts stands in stark contrast to the response to claims of amnesia from defendants. It seems apparent that the courts need better guidelines around the issue of dissociative amnesia in both populations. We think that the increasing scientific understanding of memory in the past decade (see Schacter, 1999) can meaningfully contribute to the development of such guidelines. Responsible, nonpartisan expert testimony from mental health professionals would be one step in the direction of rectifying the current state of law in regards to dissociation.

Self-Injury and Suicide Attempt in Relation with Trauma and Dissociation among Adolescents with Dissociative and Non-Dissociative Disorders.

PubMed

Kılıç, Filiz; Coşkun, Murat; Bozkurt, Hasan; Kaya, İlyas; Zoroğlu, Salih

2017-03-01

To explore the role of trauma and dissociation over self-injurious behaviors (SIB) and suicide attempts (SA) in adolescents. A total of 207 adolescents participated in the study. After conducting diagnostic interview, participants were divided into five groups as subjects with dissociative disorders (DD), attention deficit hyperactivity disorder (ADHD), major depressive disorder (MDD) and anxiety disorders (AD), and a control group (CG) without any psychiatric disorder. ADHD, MDD and AD groups were considered as non-dissociative disorders (non-DD group) in the present study. There is no significant difference between groups in terms of number and age of the subjects (p>0.05). Among all participants SIB was reported in 32.2% of females (n=37) and 25% of males (n=23) while SA was reported in 29.6% of females (n=34) and 4.4% of males (n=4). Adolescents with DD were found to experience higher rates of SIB and SA than the other groups. Dissociation was the most important variable contributing to SIB and female gender was the most efficient variable for SA. Total trauma scores were also found to be significantly higher in DD group followed by non-DD and CG respectively. SIB and SA are complex behavioral problems which may be associated with many psychiatric factors. However higher level dissociation seems as an important mediating factor, even regardless of psychiatric diagnosis, in the development of SIB and SA. More research is needed to further explore the factors effective over SIB and SA in adolescents.

Use of Computed X-ray Tomographic Data for Analyzing the Thermodynamics of a Dissociating Porous Sand/Hydrate Mixture

DOE R&D Accomplishments Database

Freifeld, Barry M.; Kneafsey, Timothy J.; Tomutsa, Liviu; Stern, Laura A.; Kirby, Stephen H.

2002-02-28

X-ray computed tomography (CT) is a method that has been used extensively in laboratory experiments for measuring rock properties and fluid transport behavior. More recently, CT scanning has been applied successfully to detect the presence and study the behavior of naturally occurring hydrates. In this study, we used a modified medical CT scanner to image and analyze the progression of a dissociation front in a synthetic methane hydrate/sand mixture. The sample was initially scanned under conditions at which the hydrate is stable (atmospheric pressure and liquid nitrogen temperature, 77 K). The end of the sample holder was then exposed to the ambient air, and the core was continuously scanned as dissociation occurred in response to the rising temperature. CT imaging captured the advancing dissociation front clearly and accurately. The evolved gas volume was monitored as a function of time. Measured by CT, the advancing hydrate dissociation front was modeled as a thermal conduction problem explicitly incorporating the enthalpy of dissociation, using the Stefan moving-boundary-value approach. The assumptions needed to perform the analysis consisted of temperatures at the model boundaries. The estimated value for thermal conductivity of 2.6 W/m K for the remaining water ice/sand mixture is higher than expected based on conduction alone; this high value may represent a lumped parameter that incorporates the processes of heat conduction, methane gas convection, and any kinetic effects that occur during dissociation. The technique presented here has broad implications for future laboratory and field testing that incorporates geophysical techniques to monitor gas hydrate dissociation.

Neuroimaging during Trance State: A Contribution to the Study of Dissociation

PubMed Central

Peres, Julio Fernando; Moreira-Almeida, Alexander; Caixeta, Leonardo; Leao, Frederico; Newberg, Andrew

2012-01-01

Despite increasing interest in pathological and non-pathological dissociation, few researchers have focused on the spiritual experiences involving dissociative states such as mediumship, in which an individual (the medium) claims to be in communication with, or under the control of, the mind of a deceased person. Our preliminary study investigated psychography – in which allegedly “the spirit writes through the medium's hand” – for potential associations with specific alterations in cerebral activity. We examined ten healthy psychographers – five less expert mediums and five with substantial experience, ranging from 15 to 47 years of automatic writing and 2 to 18 psychographies per month – using single photon emission computed tomography to scan activity as subjects were writing, in both dissociative trance and non-trance states. The complexity of the original written content they produced was analyzed for each individual and for the sample as a whole. The experienced psychographers showed lower levels of activity in the left culmen, left hippocampus, left inferior occipital gyrus, left anterior cingulate, right superior temporal gyrus and right precentral gyrus during psychography compared to their normal (non-trance) writing. The average complexity scores for psychographed content were higher than those for control writing, for both the whole sample and for experienced mediums. The fact that subjects produced complex content in a trance dissociative state suggests they were not merely relaxed, and relaxation seems an unlikely explanation for the underactivation of brain areas specifically related to the cognitive processing being carried out. This finding deserves further investigation both in terms of replication and explanatory hypotheses. PMID:23166648

Bond Dissociation Energies for Diatomic Molecules Containing 3d Transition Metals: Benchmark Scalar-Relativistic Coupled-Cluster Calculations for 20 Molecules

DOE PAGES

Cheng, Lan; Gauss, Jürgen; Ruscic, Branko; ...

2017-01-12

Benchmark scalar-relativistic coupled-cluster calculations for dissociation energies of the 20 diatomic molecules containing 3d transition metals in the 3dMLBE20 database ( J. Chem. Theory Comput. 2015, 11, 2036) are reported in this paper. Electron correlation and basis set effects are systematically studied. The agreement between theory and experiment is in general satisfactory. For a subset of 16 molecules, the standard deviation between computational and experimental values is 9 kJ/mol with the maximum deviation being 15 kJ/mol. The discrepancies between theory and experiment remain substantial (more than 20 kJ/mol) for VH, CrH, CoH, and FeH. To explore the source of themore » latter discrepancies, the analysis used to determine the experimental dissociation energies for VH and CrH is revisited. It is shown that, if improved values are used for the heterolytic C–H dissociation energies of di- and trimethylamine involved in the experimental determination, the experimental values for the dissociation energies of VH and CrH are increased by 18 kJ/mol, such that D 0(VH) = 223 ± 7 kJ/mol and D 0(CrH) = 204 ± 7 kJ/mol (or D e(VH) = 233 ± 7 kJ/mol and D e(CrH) = 214 ± 7 kJ/mol). Finally, the new experimental values agree quite well with the calculated values, showing the consistency of the computation and the measured reaction thresholds.« less

Dissociative electron attachment and vibrational excitation of CF{sub 3}Cl: Effect of two vibrational modes revisited

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tarana, Michal; JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440; Houfek, Karel

We present a study of dissociative electron attachment and vibrational excitation processes in electron collisions with the CF{sub 3}Cl molecule. The calculations are based on the two-dimensional nuclear dynamics including the C-Cl symmetric stretch coordinate and the CF{sub 3} symmetric deformation (umbrella) coordinate. The complex potential energy surfaces are calculated using the ab initio R-matrix method. The results for dissociative attachment and vibrational excitation of the umbrella mode agree quite well with experiment whereas the cross section for excitation of the C-Cl symmetric stretch vibrations is about a factor-of-three too low in comparison with experimental data.

Simultaneous 3D coincidence imaging of cationic, anionic, and neutral photo-fragments

NASA Astrophysics Data System (ADS)

Shahi, Abhishek; Albeck, Yishai; Strasser, Daniel

2018-01-01

We present the design and simulations of a 3D coincidence imaging spectrometer for fast beam photofragmentation experiments. Coincidence detection of cationic, neutral, and anionic fragments involves spectrometer aberrations that are successfully corrected by an analytical model combined with exact numerical simulations. The spectrometer performance is experimentally demonstrated by characterization of four different channels of intense 800 nm pulse interaction with F2-: F- + F photodissociation, F + F dissociative photodetachment, F+ + F dissociative ionization, and F+ + F+ coulomb explosion. Improved measurement of F2- photodissociation with a 400 nm photon allows a better determination of the F2- anion dissociation energy, 1.256 ± 0.005 eV.

Dissociation between visual perception of allocentric distance and visually directed walking of its extent.

PubMed

Kudoh, Nobuo

2005-01-01

Walking without vision to previously viewed targets was compared with visual perception of allocentric distance in two experiments. Experimental evidence had shown that physically equal distances in a sagittal plane on the ground were perceptually underestimated as compared with those in a frontoparallel plane, even under full-cue conditions. In spite of this perceptual anisotropy of space, Loomis et al (1992 Journal of Experimental Psychology. Human Perception and Performance 18 906-921) found that subjects could match both types of distances in a blind-walking task. In experiment 1 of the present study, subjects were required to reproduce the extent of allocentric distance between two targets by either walking towards the targets, or by walking in a direction incompatible with the locations of the targets. The latter condition required subjects to derive an accurate allocentric distance from information based on the perceived locations of the two targets. The walked distance in the two conditions was almost identical whether the two targets were presented in depth (depth-presentation condition) or in the frontoparallel plane (width-presentation condition). The results of a perceptual-matching task showed that the depth distances had to be much greater than the width distances in order to be judged to be equal in length (depth compression). In experiment 2, subjects were required to reproduce the extent of allocentric distance from the viewing point by blindly walking in a direction other than toward the targets. The walked distance in the depth-presentation condition was shorter than that in the width-presentation condition. This anisotropy in motor responses, however, was mainly caused by apparent overestimation of length oriented in width, not by depth compression. In addition, the walked distances were much better scaled than those in experiment 1. These results suggest that the perceptual and motor systems share a common representation of the location of targets, whereas a dissociation in allocentric distance exists between the two systems in full-cue conditions.

Electron induced dissociation in condensed-phase nitromethane I: desorption of ionic fragments.

PubMed

Bazin, Marc; Ptasińska, Sylwia; Bass, Andrew D; Sanche, Léon

2009-03-14

Low energy electron induced dissociation of condensed nitromethane was investigated by measuring the electron stimulated desorption of anions and cations from multilayer films of CH(3)NO(2) and CD(3)NO(2), using a recently constructed, high sensitivity time of flight mass spectrometer. The desorbed yields were measured as a function of incident electron energy in the range between 1 to 20 eV and as function of coverage on Pt and Xe substrates. In anion desorption experiments, the following ions were observed: H(-) (D(-)), O(-), OH(-) (OD(-)), CN(-), NCO(-), NO(2)(-), CHNO(2)(-) (CDNO(2)(-)), CH(2)NO(2)(-) (CD(2)NO(2)(-)). Resonant structure seen in all anion yield functions, is attributed to dissociative electron attachment (DEA), though certain anion signals [e.g., OH(-) (OD(-)) and CH(2)NO(2)(-) (CD(2)NO(2)(-))] are likely the result of reactive scattering by O(-) ions. The dominant desorbed cation signals are CD(3)(+) and NO(+), and the appearance potentials of these species were measured to be 12.2 and 11.5 eV, respectively. The present measurements provide information on how the electron-induced dissociation processes of this proto-typical explosive molecule are modulated by the condensed environment and on how initial dissociation events occurring on a particular molecule, may induce further dissociation.

CO activation pathways and the mechanism of Fischer–Tropsch synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ojeda, Manuel; Nabar, Rahul P.; Nilekar, Anand U.

2010-06-15

Unresolved mechanistic details of monomer formation in Fischer–Tropsch synthesis (FTS) and of its oxygen rejection routes are addressed here by combining kinetic and theoretical analyses of elementary steps on representative Fe and Co surfaces saturated with chemisorbed CO. These studies provide experimental and theoretical evidence for hydrogen-assisted CO activation as the predominant kinetically-relevant step on Fe and Co catalysts at conditions typical of FTS practice. H2 and CO kinetic effects on FTS rates and oxygen rejection selectivity (as H2O or CO2) and density functional theory estimates of activation barriers and binding energies are consistent with H-assisted CO dissociation, but notmore » with the previously accepted kinetic relevance of direct CO dissociation and chemisorbed carbon hydrogenation elementary steps. H-assisted CO dissociation removes O-atoms as H2O, while direct dissociation forms chemisorbed oxygen atoms that desorb as CO2. Direct CO dissociation routes are minor contributors to monomer formation on Fe and may become favored at high temperatures on alkali-promoted catalysts, but not on Co catalysts, which remove oxygen predominantly as H2O because of the preponderance of Hassisted CO dissociation routes. The merging of experiment and theory led to the clarification of persistent mechanistic issues previously unresolved by separate experimental and theoretical inquiries.« less

Dream-reality confusion in borderline personality disorder: a theoretical analysis

PubMed Central

Skrzypińska, Dagna; Szmigielska, Barbara

2015-01-01

This paper presents an analysis of dream-reality confusion (DRC) in relation to the characteristics of borderline personality disorder (BPD), based on research findings and theoretical considerations. It is hypothesized that people with BPD are more likely to experience DRC compared to people in non-clinical population. Several variables related to this hypothesis were identified through a theoretical analysis of the scientific literature. Sleep disturbances: problems with sleep are found in 15–95.5% of people with BPD (Hafizi, 2013), and unstable sleep and wake cycles, which occur in BPD (Fleischer et al., 2012), are linked to DRC. Dissociation: nearly two-thirds of people with BPD experience dissociative symptoms (Korzekwa and Pain, 2009) and dissociative symptoms are correlated with a fantasy proneness; both dissociative symptoms and fantasy proneness are related to DRC (Giesbrecht and Merckelbach, 2006). Negative dream content: People with BPD have nightmares more often than other people (Semiz et al., 2008); dreams that are more likely to be confused with reality tend to be more realistic and unpleasant, and are reflected in waking behavior (Rassin et al., 2001). Cognitive disturbances: Many BPD patients experience various cognitive disturbances, including problems with reality testing (Fiqueierdo, 2006; Mosquera et al., 2011), which can foster DRC. Thin boundaries: People with thin boundaries are more prone to DRC than people with thick boundaries, and people with BPD tend to have thin boundaries (Hartmann, 2011). The theoretical analysis on the basis of these findings suggests that people who suffer from BPD may be more susceptible to confusing dream content with actual waking events. PMID:26441768

Introspection of subjective feelings is sensitive and specific.

PubMed

Questienne, Laurence; van Dijck, Jean-Philippe; Gevers, Wim

2018-02-01

Conversely to behaviorist ideas, recent studies suggest that introspection can be accurate and reliable. However, an unresolved question is whether people are able to report specific aspects of their phenomenal experience, or whether they report more general nonspecific experiences. To address this question, we investigated the sensitivity and validity of our introspection for different types of conflict. Taking advantage of the congruency sequence effect, we dissociated response conflict while keeping visual conflict unchanged in a Stroop and in a priming task. Participants were subsequently asked to report on either their experience of urge to err or on their feeling of visual conflict. Depending on the focus of the introspection, subjective reports specifically followed either the response conflict or the visual conflict. These results demonstrate that our introspective reports can be sensitive and that we are able to dissociate specific aspects of our phenomenal experiences in a valid manner. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A full understanding of oxygen reduction reaction mechanism on Au(1 1 1) surface

NASA Astrophysics Data System (ADS)

Yang, Yang; Dai, Changqing; Fisher, Adrian; Shen, Yanchun; Cheng, Daojian

2017-09-01

Oxygen reduction and hydrogen peroxide reduction are technologically important reactions in energy-conversion devices. In this work, a full understanding of oxygen reduction reaction (ORR) mechanism on Au(1 1 1) surface is investigated by density functional theory (DFT) calculations, including the reaction mechanisms of O2 dissociation, OOH dissociation, and H2O2 dissociation. Among these ORR mechanisms on Au(1 1 1), the activation energy of \\text{O}2* hydrogenation reaction is much lower than that of \\text{O}2* dissociation, indicating that \\text{O}2* hydrogenation reaction is more appropriate at the first step than \\text{O}2* dissociation. In the following, H2O2 can be formed with the lower activation energy compared with the OOH dissociation reaction, and finally H2O2 could be generated as a detectable product due to the high activation energy of H2O2 dissociation reaction. Furthermore, the potential dependent free energy study suggests that the H2O2 formation is thermodynamically favorable up to 0.4 V on Au(1 1 1), reducing the overpotential for 2e - ORR process. And the elementary step of first H2O formation becomes non-spontaneous at 0.4 V, indicating the difficulty of 4e - reduction pathway. Our DFT calculations show that H2O2 can be generated on Au(1 1 1) and the first electron transfer is the rate determining step. Our results show that gold surface could be used as a good catalyst for small-scale manufacture and on-site production of H2O2.

The Frequency of Involuntary Autobiographical Memories and Future Thoughts in Relation to Daydreaming, Emotional Distress, and Age

PubMed Central

Berntsen, Dorthe; Rubin, David C.; Salgado, Sinue

2015-01-01

We introduce a new scale, the Involuntary Autobiographical Memory Inventory (IAMI), for measuring the frequency of involuntary autobiographical memories and involuntary future thoughts. Using the scale in relation to other psychometric and demographic measures provided three important, novel findings. First, the frequency of involuntary and voluntary memories and future thoughts are similarly related to general measures of emotional distress. This challenges the idea that the involuntary mode is uniquely associated with emotional distress. Second, the frequency of involuntary autobiographical remembering does not decline with age, whereas measures of daydreaming, suppression of unwanted thoughts and dissociative experiences all do. Thus, involuntary autobiographical remembering relates differently to aging than daydreaming and other forms of spontaneous and uncontrollable thoughts. Third, unlike involuntary autobiographical remembering, the frequency of future thoughts does decrease with age. This finding underscores the need for examining past and future mental time travel in relation to aging and life span development. PMID:26241025

Multiplexed and scalable super-resolution imaging of three-dimensional protein localization in size-adjustable tissues.

PubMed

Ku, Taeyun; Swaney, Justin; Park, Jeong-Yoon; Albanese, Alexandre; Murray, Evan; Cho, Jae Hun; Park, Young-Gyun; Mangena, Vamsi; Chen, Jiapei; Chung, Kwanghun

2016-09-01

The biology of multicellular organisms is coordinated across multiple size scales, from the subnanoscale of molecules to the macroscale, tissue-wide interconnectivity of cell populations. Here we introduce a method for super-resolution imaging of the multiscale organization of intact tissues. The method, called magnified analysis of the proteome (MAP), linearly expands entire organs fourfold while preserving their overall architecture and three-dimensional proteome organization. MAP is based on the observation that preventing crosslinking within and between endogenous proteins during hydrogel-tissue hybridization allows for natural expansion upon protein denaturation and dissociation. The expanded tissue preserves its protein content, its fine subcellular details, and its organ-scale intercellular connectivity. We use off-the-shelf antibodies for multiple rounds of immunolabeling and imaging of a tissue's magnified proteome, and our experiments demonstrate a success rate of 82% (100/122 antibodies tested). We show that specimen size can be reversibly modulated to image both inter-regional connections and fine synaptic architectures in the mouse brain.

Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation

NASA Technical Reports Server (NTRS)

Norbury, John W.; Adamczyk, Anne; Dick, Frank

2008-01-01

Differential cross sections for electromagnetic dissociation in nuclear collisions are calculated for the first time. In order to be useful for three - dimensional transport codes, these cross sections have been calculated in both the projectile and lab frames. The formulas for these cross sections are such that they can be immediately used in space radiation transport codes. Only a limited amount of data exists, but the comparison between theory and experiment is good.

Memory Performance for Everyday Motivational and Neutral Objects Is Dissociable from Attention

PubMed Central

Schomaker, Judith; Wittmann, Bianca C.

2017-01-01

Episodic memory is typically better for items coupled with monetary reward or punishment during encoding. It is yet unclear whether memory is also enhanced for everyday objects with appetitive or aversive values learned through a lifetime of experience, and to what extent episodic memory enhancement for motivational and neutral items is attributable to attention. In a first experiment, we investigated attention to everyday motivational objects using eye-tracking during free-viewing and subsequently tested episodic memory using a remember/know procedure. Attention was directed more to aversive stimuli, as evidenced by longer viewing durations, whereas recollection was higher for both appetitive and aversive objects. In the second experiment, we manipulated the visual contrast of neutral objects through changes of contrast to further dissociate attention and memory encoding. While objects presented with high visual contrast were looked at longer, recollection was best for objects presented in unmodified, medium contrast. Generalized logistic mixed models on recollection performance showed that attention as measured by eye movements did not enhance subsequent memory, while motivational value (Experiment 1) and visual contrast (Experiment 2) had quadratic effects in opposite directions. Our findings suggest that an enhancement of incidental memory encoding for appetitive items can occur without an increase in attention and, vice versa, that enhanced attention towards salient neutral objects is not necessarily associated with memory improvement. Together, our results provide evidence for a double dissociation of attention and memory effects under certain conditions. PMID:28694774

ENVIRONMENTALLY BENIGN MITIGATION OF MICROBIOLOGICALLY INFLUENCED CORROSION (MIC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. Robert Paterek; Gemma Husmillo

The overall program objective is to develop and evaluate environmental benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is one or more environmental benign, a.k.a. ''green'' products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Capsicum sp. extracts and pure compounds were screened for their antimicrobial activity against MIC causing bacteria. Studies on the ability of these compounds to dissociate biofilm from the substratum were conducted using microtiter plate assays. Tests usingmore » laboratory scale pipeline simulators continued. Preliminary results showed that the natural extracts possess strong antimicrobial activity being comparable to or even better than the pure compounds tested against strains of sulfate reducers. Their minimum inhibitory concentrations had been determined. It was also found that they possess bactericidal properties at minimal concentrations. Biofilm dissociation activity as assessed by microtiter plate assays demonstrated varying degrees of differences between the treated and untreated group with the superior performance of the extracts over pure compounds. Such is an indication of the possible benefits that could be obtained from these natural products. Confirmatory experiments are underway.« less