The basal ganglia is necessary for learning spectral, but not temporal features of birdsong

PubMed Central

Ali, Farhan; Fantana, Antoniu L.; Burak, Yoram; Ölveczky, Bence P.

2013-01-01

Executing a motor skill requires the brain to control which muscles to activate at what times. How these aspects of control - motor implementation and timing - are acquired, and whether the learning processes underlying them differ, is not well understood. To address this we used a reinforcement learning paradigm to independently manipulate both spectral and temporal features of birdsong, a complex learned motor sequence, while recording and perturbing activity in underlying circuits. Our results uncovered a striking dissociation in how neural circuits underlie learning in the two domains. The basal ganglia was required for modifying spectral, but not temporal structure. This functional dissociation extended to the descending motor pathway, where recordings from a premotor cortex analogue nucleus reflected changes to temporal, but not spectral structure. Our results reveal a strategy in which the nervous system employs different and largely independent circuits to learn distinct aspects of a motor skill. PMID:24075977

Differential associations between types of verbal memory and prefrontal brain structure in healthy aging and late life depression.

PubMed

Lamar, Melissa; Charlton, Rebecca; Zhang, Aifeng; Kumar, Anand

2012-07-01

Verbal memory deficits attributed to late life depression (LLD) may result from executive dysfunction that is more detrimental to list-learning than story-based recall when compared to healthy aging. Despite these behavioral dissociations, little work has been done investigating related neuroanatomical dissociations across types of verbal memory performance in LLD. We compared list-learning to story-based memory performance in 24 non-demented individuals with LLD (age ~ 66.1 ± 7.8) and 41 non-demented/non-depressed healthy controls (HC; age ~ 67.6 ± 5.3). We correlated significant results of between-group analyses across memory performance variables with brain volumes of frontal, temporal and parietal regions known to be involved with verbal learning and memory. When compared to the HC group, the LLD group showed significantly lower verbal memory performance for spontaneous recall after repeated exposure and after a long-delay but only for the list-learning task; groups did not differ on story-based memory performance. Despite equivalent brain volumes across regions, only the LLD group showed brain associations with verbal memory performance and only for the list-learning task. Specifically, frontal volumes important for subjective organization and response monitoring correlated with list-learning performance in the LLD group. This study is the first to demonstrate neuroanatomical dissociations across types of verbal memory performance in individuals with LLD. Results provide structural evidence for the behavioral dissociations between list-learning and story-based recall in LLD when compared to healthy aging. More specifically, it points toward a network of predominantly anterior brain regions that may underlie the executive contribution to list-learning in older adults with depression. Copyright © 2012 Elsevier Ltd. All rights reserved.

Differential Relationships between RAN Performance, Behaviour Ratings, and Executive Function Measures: Searching for a Double Dissociation

ERIC Educational Resources Information Center

Stringer, Ronald W.; Toplak, Maggie E.; Stanovich, Keith E.

2004-01-01

In this study, we investigated the relationships between rapid naming of letters, digits and colours, and reading ability and executive function. We gave fifty-six grade three and four children rapid automatised naming tasks using letters and digits as stimuli, executive function measures including the Stroop task, a working memory task and the…

Pseudo-Random Number Generation in Children with High-Functioning Autism and Asperger's Disorder: Further Evidence for a Dissociation in Executive Functioning?

ERIC Educational Resources Information Center

Rinehart, Nicole J.; Bradshaw, John L.; Moss, Simon A.; Brereton, Avril V.; Tonge, Bruce J.

2006-01-01

The repetitive, stereotyped and obsessive behaviours, which are core diagnostic features of autism, are thought to be underpinned by executive dysfunction. This study examined executive impairment in individuals with autism and Asperger's disorder using a verbal equivalent of an established pseudo-random number generating task. Different patterns…

Dissociable contributions of MRI volume reductions of superior temporal and fusiform gyri to symptoms and neuropsychology in schizophrenia.

PubMed

Nestor, Paul G; Onitsuka, Toshiaki; Gurrera, Ronald J; Niznikiewicz, Margaret; Frumin, Melissa; Shenton, Martha E; McCarley, Robert W

2007-03-01

We sought to identify the functional correlates of reduced magnetic resonance imaging (MRI) volumes of the superior temporal gyrus (STG) and the fusiform gyrus (FG) in patients with chronic schizophrenia. MRI volumes, positive/negative symptoms, and neuropsychological tests of facial memory and executive functioning were examined within the same subjects. The results indicated two distinct, dissociable brain structure-function relationships: (1) reduced left STG volume-positive symptoms-executive deficits; (2) reduced left FG-negative symptoms-facial memory deficits. STG and FG volume reductions may each make distinct contributions to symptoms and cognitive deficits of schizophrenia.

Motor cortex is required for learning but not executing a motor skill

PubMed Central

Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu; Dhawale, Ashesh; Kampff, Adam R.; Ölveczky, Bence P.

2018-01-01

Motor cortex is widely believed to underlie the acquisition and execution of motor skills, yet its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex’s established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in ‘tutoring’ these circuits during learning. PMID:25892304

Inconsistency in serial choice decision and motor reaction times dissociate in younger and older adults.

PubMed

Bunce, David; MacDonald, Stuart W S; Hultsch, David F

2004-12-01

Intraindividual variability (inconsistency) in reaction time (RT) latencies was investigated in a group of younger (M=25.46 years) and older (M=69.29 years) men. Both groups performed 300 trials in 2-, 4-, and 8-choice RT conditions where RTs for decision and motor components of the task were recorded separately. A dissociation was evident in that inconsistency was greater in older adults for decision RTs when task demands relating to the number of choices and fatigue arising from time-on-task were high. For younger persons, a weak trend toward greater inconsistency in motor RTs was evident. The results are consistent with accounts suggesting that inconsistency in neurobiological mechanisms increases with age, and that attentional lapses or fluctuations in executive control contribute to RT inconsistency.

Chinese preschoolers' implicit and explicit false-belief understanding.

PubMed

Wang, Bo; Low, Jason; Jing, Zhang; Qinghua, Qu

2012-03-01

Mandarin-speaking preschoolers in Mainland China (3- to 4-year-olds; N= 192) were tested for dissociations between anticipatory looking (AL) and verbal judgments on false-belief tasks. The dissociation between the two kinds of understanding was robust despite direct false-belief test questions using a Mandarin specific think-falsely verb and despite participants living in a culture that promotes early self-control. Children showed coherent AL across different belief-formation scenarios. Manipulation of inhibitory demand in the false-belief task did not affect preschoolers' verbal judgments any more than their AL, and yet separate measures executive function correlated only with direct judgments and not looking responses. The findings are discussed in terms of an implicit-explicit cognitive systems account of false-belief understanding. © 2011 The British Psychological Society.

Dissociations between developmental dyslexias and attention deficits

PubMed Central

Lukov, Limor; Friedmann, Naama; Shalev, Lilach; Khentov-Kraus, Lilach; Shalev, Nir; Lorber, Rakefet; Guggenheim, Revital

2014-01-01

We examine whether attention deficits underlie developmental dyslexia, or certain types of dyslexia, by presenting double dissociations between the two. We took into account the existence of distinct types of dyslexia and of attention deficits, and focused on dyslexias that may be thought to have an attentional basis: letter position dyslexia (LPD), in which letters migrate within words, attentional dyslexia (AD), in which letters migrate between words, neglect dyslexia, in which letters on one side of the word are omitted or substituted, and surface dyslexia, in which words are read via the sublexical route. We tested 110 children and adults with developmental dyslexia and/or attention deficits, using extensive batteries of reading and attention. For each participant, the existence of dyslexia and the dyslexia type were tested using reading tests that included stimuli sensitive to the various dyslexia types. Attention deficit and its type was established through attention tasks assessing sustained, selective, orienting, and executive attention functioning. Using this procedure, we identified 55 participants who showed a double dissociation between reading and attention: 28 had dyslexia with normal attention and 27 had attention deficits with normal reading. Importantly, each dyslexia with suspected attentional basis dissociated from attention: we found 21 individuals with LPD, 13 AD, 2 neglect dyslexia, and 12 surface dyslexia without attention deficits. Other dyslexia types (vowel dyslexia, phonological dyslexia, visual dyslexia) also dissociated from attention deficits. Examination of 55 additional individuals with both a specific dyslexia and a certain attention deficit found no attention function that was consistently linked with any dyslexia type. Specifically, LPD and AD dissociated from selective attention, neglect dyslexia dissociated from orienting, and surface dyslexia dissociated from sustained and executive attention. These results indicate that visuospatial attention deficits do not underlie these dyslexias. PMID:25628578

Dissociations between developmental dyslexias and attention deficits.

PubMed

Lukov, Limor; Friedmann, Naama; Shalev, Lilach; Khentov-Kraus, Lilach; Shalev, Nir; Lorber, Rakefet; Guggenheim, Revital

2014-01-01

We examine whether attention deficits underlie developmental dyslexia, or certain types of dyslexia, by presenting double dissociations between the two. We took into account the existence of distinct types of dyslexia and of attention deficits, and focused on dyslexias that may be thought to have an attentional basis: letter position dyslexia (LPD), in which letters migrate within words, attentional dyslexia (AD), in which letters migrate between words, neglect dyslexia, in which letters on one side of the word are omitted or substituted, and surface dyslexia, in which words are read via the sublexical route. We tested 110 children and adults with developmental dyslexia and/or attention deficits, using extensive batteries of reading and attention. For each participant, the existence of dyslexia and the dyslexia type were tested using reading tests that included stimuli sensitive to the various dyslexia types. Attention deficit and its type was established through attention tasks assessing sustained, selective, orienting, and executive attention functioning. Using this procedure, we identified 55 participants who showed a double dissociation between reading and attention: 28 had dyslexia with normal attention and 27 had attention deficits with normal reading. Importantly, each dyslexia with suspected attentional basis dissociated from attention: we found 21 individuals with LPD, 13 AD, 2 neglect dyslexia, and 12 surface dyslexia without attention deficits. Other dyslexia types (vowel dyslexia, phonological dyslexia, visual dyslexia) also dissociated from attention deficits. Examination of 55 additional individuals with both a specific dyslexia and a certain attention deficit found no attention function that was consistently linked with any dyslexia type. Specifically, LPD and AD dissociated from selective attention, neglect dyslexia dissociated from orienting, and surface dyslexia dissociated from sustained and executive attention. These results indicate that visuospatial attention deficits do not underlie these dyslexias.

Strategic modulation of cognitive control.

PubMed

Lungu, Ovidiu V; Liu, Tao; Waechter, Tobias; Willingham, Daniel T; Ashe, James

2007-08-01

The neural substrate of cognitive control is thought to comprise an evaluative component located in the anterior cingulate cortex (ACC) and an executive component in the prefrontal cortex (PFC). The control mechanism itself is mainly local, triggered by response conflict (monitored by the ACC) and involving the allocation of executive resources (recruited by the PFC) in a trial-to-trial fashion. However, another way to achieve control would be to use a strategic mechanism based on long-term prediction of upcoming events and on a chronic response strategy that ignores local features of the task. In the current study, we showed that such a strategic control mechanism was based on a functional dissociation or complementary relationship between the ACC and the PFC. When information in the environment was available to make predictions about upcoming stimuli, local task features (e.g., response conflict) were no longer used as a control signal. We suggest that having separate control mechanisms based on local or global task features allows humans to be persistent in pursuing their goals, yet flexible enough to adapt to changes in the environment.

Relationships among attention networks and physiological responding to threat.

PubMed

Sarapas, Casey; Weinberg, Anna; Langenecker, Scott A; Shankman, Stewart A

2017-02-01

Although researchers have long hypothesized a relationship between attention and anxiety, theoretical and empirical accounts of this relationship have conflicted. We attempted to resolve these conflicts by examining relationships of attentional abilities with responding to predictable and unpredictable threat - related but distinct motivational process implicated in a number of anxiety disorders. Eighty-one individuals completed a behavioral task assessing efficiency of three components of attention - alerting, orienting, and executive control (Attention Network Test - Revised). We also assessed startle responding during anticipation of both predictable, imminent threat (of mild electric shock) and unpredictable contextual threat. Faster alerting and slower disengaging from non-emotional attention cues were related to heightened responding to unpredictable threat, whereas poorer executive control of attention was related to heightened responding to predictable threat. This double dissociation helps to integrate models of attention and anxiety and may be informative for treatment development. Copyright © 2016 Elsevier Inc. All rights reserved.

Relationships Among Attention Networks and Physiological Responding to Threat

PubMed Central

Sarapas, Casey; Weinberg, Anna; Langenecker, Scott A.

2016-01-01

Although researchers have long hypothesized a relationship between attention and anxiety, theoretical and empirical accounts of this relationship have conflicted. We attempted to resolve these conflicts by examining relationships of attentional abilities with responding to predictable and unpredictable threat, related but distinct motivational process implicated in a number of anxiety disorders. Eighty-one individuals completed a behavioral task assessing efficiency of three components of attention – alerting, orienting, and executive control (Attention Network Test - Revised). We also assessed startle responding during anticipation of both predictable, imminent threat (of mild electric shock) and unpredictable contextual threat. Faster alerting and slower disengaging from non-emotional attention cues were related to heightened responding to unpredictable threat, whereas poorer executive control of attention was related to heightened responding to predictable threat. This double dissociation helps to integrate models of attention and anxiety and may be informative for treatment development. PMID:27816781

A Novel Robot System Integrating Biological and Mechanical Intelligence Based on Dissociated Neural Network-Controlled Closed-Loop Environment.

PubMed

Li, Yongcheng; Sun, Rong; Wang, Yuechao; Li, Hongyi; Zheng, Xiongfei

2016-01-01

We propose the architecture of a novel robot system merging biological and artificial intelligence based on a neural controller connected to an external agent. We initially built a framework that connected the dissociated neural network to a mobile robot system to implement a realistic vehicle. The mobile robot system characterized by a camera and two-wheeled robot was designed to execute the target-searching task. We modified a software architecture and developed a home-made stimulation generator to build a bi-directional connection between the biological and the artificial components via simple binomial coding/decoding schemes. In this paper, we utilized a specific hierarchical dissociated neural network for the first time as the neural controller. Based on our work, neural cultures were successfully employed to control an artificial agent resulting in high performance. Surprisingly, under the tetanus stimulus training, the robot performed better and better with the increasement of training cycle because of the short-term plasticity of neural network (a kind of reinforced learning). Comparing to the work previously reported, we adopted an effective experimental proposal (i.e. increasing the training cycle) to make sure of the occurrence of the short-term plasticity, and preliminarily demonstrated that the improvement of the robot's performance could be caused independently by the plasticity development of dissociated neural network. This new framework may provide some possible solutions for the learning abilities of intelligent robots by the engineering application of the plasticity processing of neural networks, also for the development of theoretical inspiration for the next generation neuro-prostheses on the basis of the bi-directional exchange of information within the hierarchical neural networks.

A Novel Robot System Integrating Biological and Mechanical Intelligence Based on Dissociated Neural Network-Controlled Closed-Loop Environment

PubMed Central

Wang, Yuechao; Li, Hongyi; Zheng, Xiongfei

2016-01-01

We propose the architecture of a novel robot system merging biological and artificial intelligence based on a neural controller connected to an external agent. We initially built a framework that connected the dissociated neural network to a mobile robot system to implement a realistic vehicle. The mobile robot system characterized by a camera and two-wheeled robot was designed to execute the target-searching task. We modified a software architecture and developed a home-made stimulation generator to build a bi-directional connection between the biological and the artificial components via simple binomial coding/decoding schemes. In this paper, we utilized a specific hierarchical dissociated neural network for the first time as the neural controller. Based on our work, neural cultures were successfully employed to control an artificial agent resulting in high performance. Surprisingly, under the tetanus stimulus training, the robot performed better and better with the increasement of training cycle because of the short-term plasticity of neural network (a kind of reinforced learning). Comparing to the work previously reported, we adopted an effective experimental proposal (i.e. increasing the training cycle) to make sure of the occurrence of the short-term plasticity, and preliminarily demonstrated that the improvement of the robot’s performance could be caused independently by the plasticity development of dissociated neural network. This new framework may provide some possible solutions for the learning abilities of intelligent robots by the engineering application of the plasticity processing of neural networks, also for the development of theoretical inspiration for the next generation neuro-prostheses on the basis of the bi-directional exchange of information within the hierarchical neural networks. PMID:27806074

Pragmatic and executive functions in traumatic brain injury and right brain damage: An exploratory comparative study

PubMed Central

Zimmermann, Nicolle; Gindri, Gigiane; de Oliveira, Camila Rosa; Fonseca, Rochele Paz

2011-01-01

Objective To describe the frequency of pragmatic and executive deficits in right brain damaged (RBD) and in traumatic brain injury (TBI) patients, and to verify possible dissociations between pragmatic and executive functions in these two groups. Methods The sample comprised 7 cases of TBI and 7 cases of RBD. All participants were assessed by means of tasks from the Montreal Communication Evaluation Battery and executive functions tests including the Trail Making Test, Hayling Test, Wisconsin Card Sorting Test, semantic and phonemic verbal fluency tasks, and working memory tasks from the Brazilian Brief Neuropsychological Assessment Battery NEUPSILIN. Z-score was calculated and a descriptive analysis of frequency of deficits (Z< -1.5) was carried out. Results RBD patients presented with deficits predominantly on conversational and narrative discursive tasks, while TBI patients showed a wider spread pattern of pragmatic deficits. Regarding EF, RBD deficits included predominantly working memory and verbal initiation impairment. On the other hand, TBI individuals again exhibited a general profile of executive dysfunction, affecting mainly working memory, initiation, inhibition, planning and switching. Pragmatic and executive deficits were generally associated upon comparisons of RBD patients and TBI cases, except for two simple dissociations: two post-TBI cases showed executive deficits in the absence of pragmatic deficits. Discussion Pragmatic and executive deficits can be very frequent following TBI or vascular RBD. There seems to be an association between these abilities, indicating that although they can co-occur, a cause-consequence relationship cannot be the only hypothesis. PMID:29213762

Response Inhibition in Adults with Autism Spectrum Disorder Compared to Attention Deficit/Hyperactivity Disorder

ERIC Educational Resources Information Center

Johnston, Kate; Madden, Anya K.; Bramham, Jessica; Russell, Ailsa J.

2011-01-01

Autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD) are hypothesised to involve core deficits in executive function. Previous studies have found evidence of a double dissociation between the disorders on specific executive functions (planning and response inhibition). To date most research has been conducted with…

Executive Function in Preschoolers: A Review Using an Integrative Framework

ERIC Educational Resources Information Center

Garon, Nancy; Bryson, Susan E.; Smith, Isabel M.

2008-01-01

During the last 2 decades, major advances have been made in understanding the development of executive functions (EFs) in early childhood. This article reviews the EF literature during the preschool period using an integrative framework. The framework adopted considers EF to be a unitary construct with partially dissociable components (A. Miyake…

Executive Function Subcomponents and their Relations to Everyday Functioning in Healthy Older Adults

PubMed Central

McAlister, Courtney; Schmitter-Edgecombe, Maureen

2016-01-01

Everyday functioning and its executive functioning cognitive correlates (i.e., switching, inhibition, and updating) were investigated in healthy older adults (HOAs) using multiple methods of functional status. In addition to whether computerized experimental tasks would better dissociate these subcomponents than neuropsychological measures of executive functioning, we were also interested in the contributions of both experimental and neuropsychological measures of executive function subcomponents to functional abilities. Seventy HOAs (45 young-old and 25 old-old) and 70 younger adults completed executive function and neuropsychological tests. In addition to self- and informant questionnaires of functional abilities, HOAs completed two performance-based measures. An aging effect was found on all executive function measures. Old-old older adults and their informants did not report more functional difficulties but demonstrated more difficulties on performance-based measures relative to young-old participants. For the HOAs, after controlling for age and education, the neuropsychological measures of executive functioning, but not experimental measures, explained a significant amount of variance in the informant-report and both performance-based measures. Updating measures differentially predicted performance-based measures, while switching was important for questionnaire and performance-based measures. The contribution of executive functioning to functional status when measured with experimental measures specifically designed to isolate the executive subcomponent was not as strong as hypothesized. Further research examining the value of isolating executive function subcomponents in neuropsychological assessment and the prediction of functional abilities in older adults is warranted. PMID:27206842

Executive function subcomponents and their relations to everyday functioning in healthy older adults.

PubMed

McAlister, Courtney; Schmitter-Edgecombe, Maureen

2016-10-01

Everyday functioning and its executive functioning cognitive correlates (i.e., switching, inhibition, and updating) were investigated in healthy older adults (HOAs) using multiple methods of functional status. In addition to whether computerized experimental tasks would better dissociate these subcomponents than neuropsychological measures of executive functioning, we were also interested in the contributions of both experimental and neuropsychological measures of executive function subcomponents to functional abilities. Seventy HOAs (45 young-old and 25 old-old) and 70 younger adults completed executive function and neuropsychological tests. In addition to self- and informant questionnaires of functional abilities, HOAs completed two performance-based measures. An aging effect was found on all executive function measures. Old-old older adults and their informants did not report more functional difficulties but demonstrated more difficulties on performance-based measures than did young-old participants. For the HOAs, after controlling for age and education, the neuropsychological measures of executive functioning, but not experimental measures, explained a significant amount of variance in the informant-report and both performance-based measures. Updating measures differentially predicted performance-based measures, while switching was important for questionnaire and performance-based measures. The contribution of executive functioning to functional status when measured with experimental measures specifically designed to isolate the executive subcomponent was not as strong as hypothesized. Further research examining the value of isolating executive function subcomponents in neuropsychological assessment and the prediction of functional abilities in older adults is warranted.

Dissociable attentional and affective circuits in medication-naïve children with attention-deficit/hyperactivity disorder.

PubMed

Posner, Jonathan; Rauh, Virginia; Gruber, Allison; Gat, Inbal; Wang, Zhishun; Peterson, Bradley S

2013-07-30

Current neurocognitive models of attention-deficit/hyperactivity disorder (ADHD) suggest that neural circuits involving both attentional and affective processing make independent contributions to the phenomenology of the disorder. However, a clear dissociation of attentional and affective circuits and their behavioral correlates has yet to be shown in medication-naïve children with ADHD. Using resting-state functional connectivity MRI (rs-fcMRI) in a cohort of medication naïve children with (N=22) and without (N=20) ADHD, we demonstrate that children with ADHD have reduced connectivity in two neural circuits: one underlying executive attention (EA) and the other emotional regulation (ER). We also demonstrate a double dissociation between these two neural circuits and their behavioral correlates such that reduced connectivity in the EA circuit correlates with executive attention deficits but not with emotional lability, while on the other hand, reduced connectivity in the ER circuit correlates with emotional lability but not with executive attention deficits. These findings suggest potential avenues for future research such as examining treatment effects on these two neural circuits as well as the potential prognostic and developmental significance of disturbances in one circuit vs the other. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Strategy modulates spatial perspective-taking: evidence for dissociable disembodied and embodied routes

PubMed Central

Gardner, Mark R.; Brazier, Mark; Edmonds, Caroline J.; Gronholm, Petra C.

2013-01-01

Previous research provides evidence for a dissociable embodied route to spatial perspective-taking that is under strategic control. The present experiment investigated further the influence of strategy on spatial perspective-taking by assessing whether participants may also elect to employ a separable “disembodied” route loading on inhibitory control mechanisms. Participants (N = 92) undertook both the “own body transformation” (OBT) perspective-taking task, requiring speeded spatial judgments made from the perspective of an observed figure, and a control task measuring ability to inhibit spatially compatible responses in the absence of a figure. Perspective-taking performance was found to be related to performance on the response inhibition control task, in that participants who tended to take longer to adopt a new perspective also tended to show a greater elevation in response times when inhibiting spatially compatible responses. This relationship was restricted to those participants reporting that they adopted the perspective of another by reversing left and right whenever confronted with a front-view figure; it was absent in those participants who reported perspective-taking by mentally transforming their spatial orientation to align with that of the figure. Combined with previously published results, these findings complete a double dissociation between embodied and disembodied routes to spatial perspective-taking, implying that spatial perspective-taking is subject to modulation by strategy, and suggesting that embodied routes to perspective-taking may place minimal demands on domain general executive functions. PMID:23964229

Motor cortex is required for learning but not for executing a motor skill.

PubMed

Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu L; Dhawale, Ashesh K; Kampff, Adam R; Ölveczky, Bence P

2015-05-06

Motor cortex is widely believed to underlie the acquisition and execution of motor skills, but its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex's established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in "tutoring" these circuits during learning. Copyright © 2015 Elsevier Inc. All rights reserved.

Deception dissociates from false belief reasoning in deaf children: implications for the implicit versus explicit theory of mind distinction.

PubMed

de Villiers, Peter A; de Villiers, Jill G

2012-03-01

Deception is a controversial aspect of theory of mind, and researchers disagree about whether it entails an understanding of the false beliefs of one's opponent. The present study asks whether children with delayed language and delayed explicit false belief reasoning can succeed on explicit deception tasks. Participants were 45 orally taught deaf children with varying language delays aged 4.5-8 years and 45 hearing children aged 3.5-6 years. Participants received a battery of language, executive function, deception, and both verbal and low-verbal false belief tasks. The result reveal a dissociation of deception and false belief tasks: the deaf children are on par with their hearing peers on deception games, but show significant delays in false belief tasks even when the language demands are made minimal. Furthermore, different skills are predictors of success for the two types of task in the deaf children: language, and in particular complement syntax, is the best predictor of false belief reasoning; but executive function skills, especially inhibitory control, are the best predictors of deception. It is argued that deception at this level can be handled by behaviour rules without reference to mental states. © 2011 The British Psychological Society.

Age-related changes in overcoming proactive interference in associative memory: The role of PFC-mediated executive control processes at retrieval.

PubMed

Dulas, Michael R; Duarte, Audrey

2016-05-15

Behavioral evidence has shown age-related impairments in overcoming proactive interference in memory, but it is unclear what underlies this deficit. Imaging studies in the young suggest overcoming interference may require several executive control processes supported by the ventrolateral prefrontal cortex (VLPFC) and dorsolateral PFC (DLPFC). The present functional magnetic resonance imaging (fMRI) study investigated whether age-related changes in dissociable executive control processes underlie deficits in overcoming proactive interference in associative memory during retrieval. Participants were tasked with remembering which associate (face or scene) objects were paired with most recently during study, under conditions of high or low proactive interference. Behavioral results demonstrated that, as interference increased, memory performance decreased similarly across groups, with slight associative memory deficits in older adults. Imaging results demonstrated that, across groups, left mid-VLPFC showed increasing activity with increasing interference, though activity did not distinguish correct from incorrect associative memory responses, suggesting this region may not directly serve in successful resolution of proactive interference, per se. Under conditions of high interference, older adults showed reduced associative memory accuracy effects in the DLPFC and anterior PFC. These results suggest that age-related PFC dysfunction may not be ubiquitous. Executive processes supported by ventral regions that detect mnemonic interference may be less affected than processes supported by dorsal and anterior regions that directly resolve interference. Copyright © 2016 Elsevier Inc. All rights reserved.

Voluntary switching between identities in dissociative identity disorder: A functional MRI case study.

PubMed

Savoy, R L; Frederick, B B; Keuroghlian, A S; Wolk, P C

2012-01-01

Patients who suffer from dissociative identity disorder present unique scientific and clinical challenges for psychology and psychiatry. We have been fortunate in working with a patient who-while undergoing functional MRI-can switch rapidly and voluntarily between her main personality (a middle-aged, high-functioning woman) and an alternate personality (a 4-6-year-old girl). A unique task was designed to isolate the processes occurring during the switches between these personalities. Data are from two imaging sessions, conducted months apart, each showing the same activated areas during switches between these personalities. The activated areas include the following: the primary sensory and motor cortex, likely associated with characteristic facial movements made during switching; the nucleus accumbens bilaterally, possibly associated with aspects of reward connected with switching; and prefrontal sites, presumably associated with the executive control involved in the switching of personalities.

Theory of mind and empathy in preclinical and clinical Huntington’s disease

PubMed Central

Adjeroud, Najia; Besnard, Jérémy; Massioui, Nicole El; Verny, Christophe; Prudean, Adriana; Scherer, Clarisse; Gohier, Bénédicte; Bonneau, Dominique

2016-01-01

We investigated cognitive and affective Theory of Mind (ToM) and empathy in patients with premanifest and manifest Huntington’s disease (HD). The relationship between ToM performance and executive skills was also examined. Sixteen preclinical and 23 clinical HD patients, and 39 healthy subjects divided into 2 control groups were given a French adaptation of the Yoni test (Shamay-Tsoory, S.G., Aharon-Peretz, J. (2007). Dissociable prefrontal networks for cognitive and affective theory of mind: a lesion study. Neuropsychologia, 45(3), 3054–67) that examines first- and second-order cognitive and affective ToM processing in separate conditions with a physical control condition. Participants were also given questionnaires of empathy and cognitive tests which mainly assessed executive functions (inhibition and mental flexibility). Clinical HD patients made significantly more errors than their controls in the first- and second-order cognitive and affective ToM conditions of the Yoni task, but exhibited no empathy deficits. However, there was no evidence that ToM impairment was related to cognitive deficits in these patients. Preclinical HD patients were unimpaired in ToM tasks and empathy measures compared with their controls. Our results are consistent with the idea that impaired affective and cognitive mentalizing emerges with the clinical manifestation of HD, but is not necessarily part of the preclinical stage. Furthermore, these impairments appear independent of executive dysfunction and empathy. PMID:26211015

Heart rate variability and cognitive processing: The autonomic response to task demands.

PubMed

Luque-Casado, Antonio; Perales, José C; Cárdenas, David; Sanabria, Daniel

2016-01-01

This study investigated variations in heart rate variability (HRV) as a function of cognitive demands. Participants completed an execution condition including the psychomotor vigilance task, a working memory task and a duration discrimination task. The control condition consisted of oddball versions (participants had to detect the rare event) of the tasks from the execution condition, designed to control for the effect of the task parameters (stimulus duration and stimulus rate) on HRV. The NASA-TLX questionnaire was used as a subjective measure of cognitive workload across tasks and conditions. Three major findings emerged from this study. First, HRV varied as a function of task demands (with the lowest values in the working memory task). Second, and crucially, we found similar HRV values when comparing each of the tasks with its oddball control equivalent, and a significant decrement in HRV as a function of time-on-task. Finally, the NASA-TLX results showed larger cognitive workload in the execution condition than in the oddball control condition, and scores variations as a function of task. Taken together, our results suggest that HRV is highly sensitive to overall demands of sustained attention over and above the influence of other cognitive processes suggested by previous literature. In addition, our study highlights a potential dissociation between objective and subjective measures of mental workload, with important implications in applied settings. Copyright © 2015 Elsevier B.V. All rights reserved.

[Psychiatric, Cognitive and Emotional Profile in Ex-combatants of Illegal Armed Groups in Colombia].

PubMed

Tobón, Carlos; Aguirre-Acevedo, Daniel Camilo; Velilla, Lina; Duque, Jon; Ramos, Claudia Patricia; Pineda, David

2016-01-01

Exposure to armed conflict produces biological adaptations oriented to handle the highly stressful conditions in war environments. The special features of The Colombian armed create a special scenario to evaluate the human behavior. In this study, psychiatric, cognitive and emotional processing characteristics of a group of Colombian armed illegal forces of ex-combatants are described. Sixty-three ex combatants and 22 controls were assessed with WAIS (IQ), INECO frontal screening (executive functions), Interpersonal Reactivity Index (empathy), emotional features recognition and MINI (psychiatric profile). When compared to the control group, ex-combatants showed higher frequency of antisocial personality disorder (P=.031) and behavioral dissocial disorder (P=.017). In cognitive profile, the ex-combatants showed a lower score in the executive function test (Me=18.50; RQ=4.00), control (Me=23.00; RQ=5.25), with a poor personal distress in emphatic profile (Me=10.00; RQ=5.00) compared to control group (Me=37.00; RQ=7.25). We found differences in cognitive and psychiatric profile in ex-combatants in comparison with controls. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

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.

A common control signal and a ballistic stage can explain the control of coordinated eye-hand movements.

PubMed

Gopal, Atul; Murthy, Aditya

2016-06-01

Voluntary control has been extensively studied in the context of eye and hand movements made in isolation, yet little is known about the nature of control during eye-hand coordination. We probed this with a redirect task. Here subjects had to make reaching/pointing movements accompanied by coordinated eye movements but had to change their plans when the target occasionally changed its position during some trials. Using a race model framework, we found that separate effector-specific mechanisms may be recruited to control eye and hand movements when executed in isolation but when the same effectors are coordinated a unitary mechanism to control coordinated eye-hand movements is employed. Specifically, we found that performance curves were distinct for the eye and hand when these movements were executed in isolation but were comparable when they were executed together. Second, the time to switch motor plans, called the target step reaction time, was different in the eye-alone and hand-alone conditions but was similar in the coordinated condition under assumption of a ballistic stage of ∼40 ms, on average. Interestingly, the existence of this ballistic stage could predict the extent of eye-hand dissociations seen in individual subjects. Finally, when subjects were explicitly instructed to control specifically a single effector (eye or hand), redirecting one effector had a strong effect on the performance of the other effector. Taken together, these results suggest that a common control signal and a ballistic stage are recruited when coordinated eye-hand movement plans require alteration. Copyright © 2016 the American Physiological Society.

A common control signal and a ballistic stage can explain the control of coordinated eye-hand movements

PubMed Central

Gopal, Atul

2016-01-01

Voluntary control has been extensively studied in the context of eye and hand movements made in isolation, yet little is known about the nature of control during eye-hand coordination. We probed this with a redirect task. Here subjects had to make reaching/pointing movements accompanied by coordinated eye movements but had to change their plans when the target occasionally changed its position during some trials. Using a race model framework, we found that separate effector-specific mechanisms may be recruited to control eye and hand movements when executed in isolation but when the same effectors are coordinated a unitary mechanism to control coordinated eye-hand movements is employed. Specifically, we found that performance curves were distinct for the eye and hand when these movements were executed in isolation but were comparable when they were executed together. Second, the time to switch motor plans, called the target step reaction time, was different in the eye-alone and hand-alone conditions but was similar in the coordinated condition under assumption of a ballistic stage of ∼40 ms, on average. Interestingly, the existence of this ballistic stage could predict the extent of eye-hand dissociations seen in individual subjects. Finally, when subjects were explicitly instructed to control specifically a single effector (eye or hand), redirecting one effector had a strong effect on the performance of the other effector. Taken together, these results suggest that a common control signal and a ballistic stage are recruited when coordinated eye-hand movement plans require alteration. PMID:26888104

Cognitive Control Structures in the Imitation Learning of Spatial Sequences and Rhythms-An fMRI Study.

PubMed

Sakreida, Katrin; Higuchi, Satomi; Di Dio, Cinzia; Ziessler, Michael; Turgeon, Martine; Roberts, Neil; Vogt, Stefan

2018-03-01

Imitation learning involves the acquisition of novel motor patterns based on action observation (AO). We used event-related functional magnetic resonance imaging to study the imitation learning of spatial sequences and rhythms during AO, motor imagery (MI), and imitative execution in nonmusicians and musicians. While both tasks engaged the fronto-parietal mirror circuit, the spatial sequence task recruited posterior parietal and dorsal premotor regions more strongly. The rhythm task involved an additional network for auditory working memory. This partial dissociation supports the concept of task-specific mirror mechanisms. Two regions of cognitive control were identified: 1) dorsolateral prefrontal cortex (DLPFC) was found to be more strongly activated during MI of novel spatial sequences, which allowed us to extend the 2-level model of imitation learning by Buccino et al. (2004) to spatial sequences. 2) During imitative execution of both tasks, the posterior medial frontal cortex was robustly activated, along with the DLPFC, which suggests that both regions are involved in the cognitive control of imitation learning. The musicians' selective behavioral advantage for rhythm imitation was reflected cortically in enhanced sensory-motor processing during AO and by the absence of practice-related activation differences in DLPFC during rhythm execution. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The Essential Role of Primate Orbitofrontal Cortex in Conflict-Induced Executive Control Adjustment

PubMed Central

Buckley, Mark J.; Tanaka, Keiji

2014-01-01

Conflict in information processing evokes trial-by-trial behavioral modulations. Influential models suggest that adaptive tuning of executive control, mediated by mid-dorsal lateral prefrontal cortex (mdlPFC) and anterior cingulate cortex (ACC), underlies these modulations. However, mdlPFC and ACC are parts of distributed brain networks including orbitofrontal cortex (OFC), posterior cingulate cortex (PCC), and superior-dorsal lateral prefrontal cortex (sdlPFC). Contributions of these latter areas in adaptive tuning of executive control are unknown. We trained monkeys to perform a matching task in which they had to resolve the conflict between two behavior-guiding rules. Here, we report that bilateral lesions in OFC, but not in PCC or sdlPFC, impaired selection between these competing rules. In addition, the behavioral adaptation that is normally induced by experiencing conflict disappeared in OFC-lesioned, but remained normal in PCC-lesioned or sdlPFC-lesioned monkeys. Exploring underlying neuronal processes, we found that the activity of neurons in OFC represented the conflict between behavioral options independent from the other aspects of the task. Responses of OFC neurons to rewards also conveyed information of the conflict level that the monkey had experienced along the course to obtain the reward. Our findings indicate dissociable functions for five closely interconnected cortical areas suggesting that OFC and mdlPFC, but not PCC or sdlPFC or ACC, play indispensable roles in conflict-dependent executive control of on-going behavior. Both mdlPFC and OFC support detection of conflict and its integration with the task goal, but in contrast to mdlPFC, OFC does not retain the necessary information for conflict-induced modulation of future decisions. PMID:25122901

Dissociation between decision-making under risk and decision-making under ambiguity in premanifest and manifest Huntington's disease.

PubMed

Adjeroud, Najia; Besnard, Jeremy; Verny, Christophe; Prundean, Adriana; Scherer, Clarisse; Gohier, Bénédicte; Bonneau, Dominique; Massioui, Nicole El; Allain, Philippe

2017-08-01

We investigated decision-making under ambiguity (DM-UA) and decision making under risk (DM-UR) in individuals with premanifest and manifest Huntington's disease (HD). Twenty individuals with premanifest HD and 23 individuals with manifest HD, on one hand, and 39 healthy individuals divided into two control groups, on the other, undertook a modified version of the Iowa Gambling Task (IGT), an adaptation of a DM-UA task, and a modified version of the Game of Dice Task (GDT), an adaptation of a DM-UR task. Participants also filled in a questionnaire of impulsivity and responded to cognitive tests specifically designed to assess executive functions. Compared to controls, individuals with premanifest HD were unimpaired in performing executive tests as well as in decision-making tasks, except for the Stroop task. In contrast, individuals with manifest HD were impaired in both the IGT and executive tasks, but not in the GDT. No sign of impulsivity was observed in individuals with premanifest or manifest HD. Our results suggest that the progression of HD impairs DM-UA without affecting DM-UR, and indicate that decision-making abilities are preserved during the premanifest stage of HD. Copyright © 2017 Elsevier Ltd. All rights reserved.

A continuum of executive function deficits in early subcortical vascular cognitive impairment: A systematic review and meta-analysis.

PubMed

Sudo, Felipe Kenji; Amado, Patricia; Alves, Gilberto Sousa; Laks, Jerson; Engelhardt, Eliasz

2017-01-01

Subcortical Vascular Cognitive Impairment (SVCI) is a clinical continuum of vascular-related cognitive impairment, including Vascular Mild Cognitive Impairment (VaMCI) and Vascular Dementia. Deficits in Executive Function (EF) are hallmarks of the disorder, but the best methods to assess this function have yet to be determined. The insidious and almost predictable course of SVCI and the multidimensional concept of EF suggest that a temporal dissociation of impairments in EF domains exists early in the disorder. This study aims to review and analyze data from the literature about performance of VaMCI patients on the most used EF tests through a meta-analytic approach. Medline, Web of Knowledge and PsycINFO were searched, using the terms: "vascular mild cognitive impairment" OR "vascular cognitive impairment no dementia" OR "vascular mild neurocognitive disorder" AND "dysexecutive" OR "executive function". Meta-analyses were conducted for each of the selected tests, using random-effect models. Systematic review showed major discrepancies among the results of the studies included. Meta-analyses evidenced poorer performance on the Trail-Making Test part B and the Stroop color test by VaMCI patients compared to controls. A continuum of EF impairments has been proposed in SVCI. Early deficits appear to occur in cognitive flexibility and inhibitory control.

Theory of mind and empathy in preclinical and clinical Huntington's disease.

PubMed

Adjeroud, Najia; Besnard, Jérémy; El Massioui, Nicole; Verny, Christophe; Prudean, Adriana; Scherer, Clarisse; Gohier, Bénédicte; Bonneau, Dominique; Allain, Philippe

2016-01-01

We investigated cognitive and affective Theory of Mind (ToM) and empathy in patients with premanifest and manifest Huntington's disease (HD). The relationship between ToM performance and executive skills was also examined. Sixteen preclinical and 23 clinical HD patients, and 39 healthy subjects divided into 2 control groups were given a French adaptation of the Yoni test (Shamay-Tsoory, S.G., Aharon-Peretz, J. (2007). Dissociable prefrontal networks for cognitive and affective theory of mind: a lesion study. Neuropsychologia, 45(3), 3054-67) that examines first- and second-order cognitive and affective ToM processing in separate conditions with a physical control condition. Participants were also given questionnaires of empathy and cognitive tests which mainly assessed executive functions (inhibition and mental flexibility). Clinical HD patients made significantly more errors than their controls in the first- and second-order cognitive and affective ToM conditions of the Yoni task, but exhibited no empathy deficits. However, there was no evidence that ToM impairment was related to cognitive deficits in these patients. Preclinical HD patients were unimpaired in ToM tasks and empathy measures compared with their controls. Our results are consistent with the idea that impaired affective and cognitive mentalizing emerges with the clinical manifestation of HD, but is not necessarily part of the preclinical stage. Furthermore, these impairments appear independent of executive dysfunction and empathy. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Contrasting patterns of deficits in visuospatial memory and executive function in patients with major depression with and without ECT referral.

PubMed

Tsaltas, E; Kalogerakou, S; Papakosta, V-M; Kontis, D; Theochari, E; Koutroumpi, M; Anyfandi, E; Michopoulos, I; Poulopoulou, C; Papadimitriou, G; Oulis, P

2011-05-01

The pretreatment neuropsychological profile of drug-resistant patients with major depressive disorder (MDD) referred for electroconvulsive therapy (ECT) may differ from that of their drug-respondent MDD counterparts. Such differences could help in identifying distinct MDD subtypes, thus offering insights into the neuropathology underlying differential treatment responses. Depressed patients with ECT referral (ECTs), depressed patients with no ECT referral (NECTs) and non-psychiatric Controls (matched groups, n=15) were assessed with memory and executive function tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB). ECTs scored significantly lower than NECTs in the Mini-Mental State Examination (MMSE; p=0.01). NECTs performed worse than Controls in the Paired Associates Learning (PAL) task (p<0.03; Control/NECT p<0.01) and the Spatial Recognition Memory (SRM) task (p<0.05; Controls/NECTs p<0.05); ECTs performed between Controls and NECTs, not differing from either. In the Intra/Extradimensional (IED) set-shifting task, ECTs performed worse that Controls and NECTS (IED: p<0.01; Controls/ECTs p<0.01), particularly in the shift phases, which suggests reduced attentional flexibility. In Stockings of Cambridge (SOC), ECTs abandoned the test early more often than Controls and NECTs (H=11, p<0.01) but ECTs who completed SOC performed comparably to the other two groups. A double dissociation emerged from the comparison of cognitive profiles of ECT and NECT patients. ECTs showed executive deficits, particularly in attentional flexibility, but mild deficits in tests of visuospatial memory. NECTs presented the opposite pattern. This suggests predominantly frontostriatal involvement in ECT versus temporal involvement in NECT depressives.

Dissociation of Subjectively Reported and Behaviorally Indexed Mind Wandering by EEG Rhythmic Activity

PubMed Central

Qin, Jungang; Perdoni, Christopher; He, Bin

2011-01-01

Inattention to current activity is ubiquitous in everyday situations. Mind wandering is an example of such a state, and its related brain areas have been examined in the literature. However, there is no clear evidence regarding neural rhythmic activities linked to mind wandering. Using a vigilance task with thought sampling and electroencephalography recording, the current study simultaneously examined neural oscillatory activities related to subjectively reported and behaviorally indexed mind wandering. By implementing time-frequency analysis, we found that subjectively reported mind wandering, relative to behaviorally indexed, showed increased gamma band activity at bilateral frontal-central areas. By means of beamformer source imaging, we found subjectively reported mind wandering within the gamma band to be characterized by increased activation in bilateral frontal cortices, supplemental motor area, paracentral cortex and right inferior temporal cortex in comparison to behaviorally indexed mind wandering. These findings dissociate subjectively reported and behaviorally indexed mind wandering and suggest that a higher degree of executive control processes are engaged in subjectively reported mind wandering. PMID:21915257

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.

A woman lost in the cemetery: A case of time-limited amnesia.

PubMed

Comparelli, A; De Carolis, A; Kotzalidis, G D; Masillo, A; Ferracuti, S; Tatarelli, R

2010-02-01

A 43-year-old woman one day experienced a dissociative fugue which she could not recall. She was married, nulliparous, with no history of dissociative disorder or other psychiatric disorders. She had been sexually abused during late childhood-early adolescence. She was examined thoroughly from both psychiatric and medical standpoints to exclude organic causes for her condition. Magnetic Resonance Imaging showed only some non-specific abnormalities. On personality tests, a histrionic structure of personality emerged, with obsessive and narcissistic traits accompanied by rigidity and anxiety, dysphoria and high risk for depression; some impairment was found in executive function tests. Final diagnosis was one of dissociative fugue. In fact, organic traits were not sufficient to establish a diagnosis of Transient Global Amnesia.

Oculomotor selection underlies feature retention in visual working memory.

PubMed

Hanning, Nina M; Jonikaitis, Donatas; Deubel, Heiner; Szinte, Martin

2016-02-01

Oculomotor selection, spatial task relevance, and visual working memory (WM) are described as three processes highly intertwined and sustained by similar cortical structures. However, because task-relevant locations always constitute potential saccade targets, no study so far has been able to distinguish between oculomotor selection and spatial task relevance. We designed an experiment that allowed us to dissociate in humans the contribution of task relevance, oculomotor selection, and oculomotor execution to the retention of feature representations in WM. We report that task relevance and oculomotor selection lead to dissociable effects on feature WM maintenance. In a first task, in which an object's location was encoded as a saccade target, its feature representations were successfully maintained in WM, whereas they declined at nonsaccade target locations. Likewise, we observed a similar WM benefit at the target of saccades that were prepared but never executed. In a second task, when an object's location was marked as task relevant but constituted a nonsaccade target (a location to avoid), feature representations maintained at that location did not benefit. Combined, our results demonstrate that oculomotor selection is consistently associated with WM, whereas task relevance is not. This provides evidence for an overlapping circuitry serving saccade target selection and feature-based WM that can be dissociated from processes encoding task-relevant locations. Copyright © 2016 the American Physiological Society.

A continuum of executive function deficits in early subcortical vascular cognitive impairment: A systematic review and meta-analysis

PubMed Central

Sudo, Felipe Kenji; Amado, Patricia; Alves, Gilberto Sousa; Laks, Jerson; Engelhardt, Eliasz

2017-01-01

ABSTRACT. Background. Subcortical Vascular Cognitive Impairment (SVCI) is a clinical continuum of vascular-related cognitive impairment, including Vascular Mild Cognitive Impairment (VaMCI) and Vascular Dementia. Deficits in Executive Function (EF) are hallmarks of the disorder, but the best methods to assess this function have yet to be determined. The insidious and almost predictable course of SVCI and the multidimensional concept of EF suggest that a temporal dissociation of impairments in EF domains exists early in the disorder. Objective: This study aims to review and analyze data from the literature about performance of VaMCI patients on the most used EF tests through a meta-analytic approach. Methods: Medline, Web of Knowledge and PsycINFO were searched, using the terms: “vascular mild cognitive impairment” OR “vascular cognitive impairment no dementia” OR “vascular mild neurocognitive disorder” AND “dysexecutive” OR “executive function”. Meta-analyses were conducted for each of the selected tests, using random-effect models. Results: Systematic review showed major discrepancies among the results of the studies included. Meta-analyses evidenced poorer performance on the Trail-Making Test part B and the Stroop color test by VaMCI patients compared to controls. Conclusion: A continuum of EF impairments has been proposed in SVCI. Early deficits appear to occur in cognitive flexibility and inhibitory control. PMID:29354217

The dissociation between command following and communication in disorders of consciousness: an fMRI study in healthy subjects.

PubMed

Osborne, Natalie R; Owen, Adrian M; Fernández-Espejo, Davinia

2015-01-01

Neuroimaging studies have identified a subgroup of patients with a Disorder of Consciousness (DOC) who, while being behaviorally non-responsive, are nevertheless able to follow commands by modulating their brain activity in motor imagery (MI) tasks. These techniques have even allowed for binary communication in a small number of DOC patients. However, the majority of patients who can follow commands are unable to use their responses to communicate. A similar dissociation between present command following (CF) and absent communication abilities has been reported in overt behavioral assessments. However, the neural correlates of this dissociation in both overt and covert modalities are unknown. Here, we used functional magnetic resonance imaging (fMRI) to explore the neural mechanisms underlying CF and selection of responses for binary communication using either executed or imagined movements. Fifteen healthy participants executed or imagined two different types of arm movements that were either pre-determined by the experimenters (CF) or decided by them (action selection, AS). Action selection involved greater activity in high-level associative areas in frontal and parietal regions than CF. Additionally, motor execution (ME), as compared to MI, activated contralateral motor cortex, while the opposite contrast revealed activation in the ipsilateral sensorimotor cortex and the left inferior frontal gyrus. Importantly, there was no interaction between the task (CF/AS) and modality (MI/ME). Our results suggest that the neural processes involved in following a motor command or selecting between two motor actions are not dependent on how the response is expressed (via ME/MI). They also suggest a potential neural basis for the distinction in cognitive abilities seen in DOC patients.

The dissociation between command following and communication in disorders of consciousness: an fMRI study in healthy subjects

PubMed Central

Osborne, Natalie R.; Owen, Adrian M.; Fernández-Espejo, Davinia

2015-01-01

Neuroimaging studies have identified a subgroup of patients with a Disorder of Consciousness (DOC) who, while being behaviorally non-responsive, are nevertheless able to follow commands by modulating their brain activity in motor imagery (MI) tasks. These techniques have even allowed for binary communication in a small number of DOC patients. However, the majority of patients who can follow commands are unable to use their responses to communicate. A similar dissociation between present command following (CF) and absent communication abilities has been reported in overt behavioral assessments. However, the neural correlates of this dissociation in both overt and covert modalities are unknown. Here, we used functional magnetic resonance imaging (fMRI) to explore the neural mechanisms underlying CF and selection of responses for binary communication using either executed or imagined movements. Fifteen healthy participants executed or imagined two different types of arm movements that were either pre-determined by the experimenters (CF) or decided by them (action selection, AS). Action selection involved greater activity in high-level associative areas in frontal and parietal regions than CF. Additionally, motor execution (ME), as compared to MI, activated contralateral motor cortex, while the opposite contrast revealed activation in the ipsilateral sensorimotor cortex and the left inferior frontal gyrus. Importantly, there was no interaction between the task (CF/AS) and modality (MI/ME). Our results suggest that the neural processes involved in following a motor command or selecting between two motor actions are not dependent on how the response is expressed (via ME/MI). They also suggest a potential neural basis for the distinction in cognitive abilities seen in DOC patients. PMID:26441593

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

Cognitive benefit and cost of acute stress is differentially modulated by individual brain state

PubMed Central

Hermans, Erno J.; Fernández, Guillén

2017-01-01

Abstract Acute stress is associated with beneficial as well as detrimental effects on cognition in different individuals. However, it is not yet known how stress can have such opposing effects. Stroop-like tasks typically show this dissociation: stress diminishes speed, but improves accuracy. We investigated accuracy and speed during a stroop-like task of 120 healthy male subjects after an experimental stress induction or control condition in a randomized, counter-balanced cross-over design; we assessed brain–behavior associations and determined the influence of individual brain connectivity patterns on these associations, which may moderate the effect and help identify stress resilience factors. In the mean, stress was associated to increase in accuracy, but decrease in speed. Accuracy was associated to brain activation in a distributed set of brain regions overlapping with the executive control network (ECN) and speed to temporo-parietal activation. In line with a stress-related large-scale network reconfiguration, individuals showing an upregulation of the salience and down-regulation of the executive-control network under stress displayed increased speed, but decreased performance. In contrast, individuals who upregulate their ECN under stress show improved performance. Our results indicate that the individual large-scale brain network balance under acute stress moderates cognitive consequences of threat. PMID:28402480

Cognitive benefit and cost of acute stress is differentially modulated by individual brain state.

PubMed

Kohn, Nils; Hermans, Erno J; Fernández, Guillén

2017-07-01

Acute stress is associated with beneficial as well as detrimental effects on cognition in different individuals. However, it is not yet known how stress can have such opposing effects. Stroop-like tasks typically show this dissociation: stress diminishes speed, but improves accuracy. We investigated accuracy and speed during a stroop-like task of 120 healthy male subjects after an experimental stress induction or control condition in a randomized, counter-balanced cross-over design; we assessed brain-behavior associations and determined the influence of individual brain connectivity patterns on these associations, which may moderate the effect and help identify stress resilience factors. In the mean, stress was associated to increase in accuracy, but decrease in speed. Accuracy was associated to brain activation in a distributed set of brain regions overlapping with the executive control network (ECN) and speed to temporo-parietal activation. In line with a stress-related large-scale network reconfiguration, individuals showing an upregulation of the salience and down-regulation of the executive-control network under stress displayed increased speed, but decreased performance. In contrast, individuals who upregulate their ECN under stress show improved performance. Our results indicate that the individual large-scale brain network balance under acute stress moderates cognitive consequences of threat. © The Author (2017). Published by Oxford University Press.

Functional brain imaging in 14 patients with dissociative amnesia reveals right inferolateral prefrontal hypometabolism.

PubMed

Brand, Matthias; Eggers, Carsten; Reinhold, Nadine; Fujiwara, Esther; Kessler, Josef; Heiss, Wolf-Dieter; Markowitsch, Hans J

2009-10-30

Dissociative amnesia is a condition usually characterized by severely impaired retrograde memory functioning in the absence of structural brain damage. Recent case studies nevertheless found functional brain changes in patients suffering from autobiographical-episodic memory loss in the cause of dissociative amnesia. Functional changes were demonstrated in both resting state and memory retrieval conditions. In addition, some but not all cases also showed other neuropsychological impairments beyond retrograde memory deficits. However, there is no group study available that examined potential functional brain abnormalities and accompanying neuropsychological deteriorations in larger samples of patients with dissociative retrograde amnesia. We report functional imaging and neuropsychological data acquired in 14 patients with dissociative amnesia following stressful or traumatic events. All patients suffered from autobiographical memory loss. In addition, approximately half of the patients had deficits in anterograde memory and executive functioning. Accompanying functional brain changes were measured by [18F]fluorodeoxyglucose positron emission tomography (FDG-PET). Regional glucose utilization of the patients was compared with that of 19 healthy subjects, matched for age and gender. We found significantly decreased glucose utilization in the right inferolateral prefrontal cortex in the patients. Hypometabolism in this brain region, known to be involved in retrieval of autobiographical memories and self-referential processing, may be a functional brain correlate of dissociative amnesia.

Disassociation between brain activation and executive function in fragile X premutation females.

PubMed

Shelton, Annie L; Cornish, Kim; Clough, Meaghan; Gajamange, Sanuji; Kolbe, Scott; Fielding, Joanne

2017-02-01

Executive dysfunction has been demonstrated among premutation (PM) carriers (55-199 CGG repeats) of the Fragile X mental retardation 1 (FMR1) gene. Further, alterations to neural activation patterns have been reported during memory and comparison based functional magnetic resonance imaging (fMRI) tasks in these carriers. For the first time, the relationships between fMRI neural activation during an interleaved ocular motor prosaccade/antisaccade paradigm, and concurrent task performance (saccade measures of latency, accuracy and error rate) in PM females were examined. Although no differences were found in whole brain activation patterns, regions of interest (ROI) analyses revealed reduced activation in the right ventrolateral prefrontal cortex (VLPFC) during antisaccade trials for PM females. Further, a series of divergent and group specific relationships were found between ROI activation and saccade measures. Specifically, for control females, activation within the right VLPFC and supramarginal gyrus correlated negatively with antisaccade latencies, while for PM females, activation within these regions was found to negatively correlate with antisaccade accuracy and error rate (right VLPFC only). For control females, activation within frontal and supplementary eye fields and bilateral intraparietal sulci correlated with prosaccade latency and accuracy; however, no significant prosaccade correlations were found for PM females. This exploratory study extends previous reports of altered prefrontal neural engagement in PM carriers, and clearly demonstrates dissociation between control and PM females in the transformation of neural activation into overt measures of executive dysfunction. Hum Brain Mapp 38:1056-1067, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Is the frontal dysexecutive syndrome due to a working memory deficit? Evidence from patients with stroke.

PubMed

Roussel, Martine; Dujardin, Kathy; Hénon, Hilde; Godefroy, Olivier

2012-07-01

Although frontal dysexecutive disorders are frequently considered to be due to working memory deficit, this has not been systematically examined and very little evidence is available for impairment of working memory in frontal damage. The objective of this study was to examine the components of working memory, their anatomy and the relations with executive functions in patients with stroke involving the frontal or posterior cortex. The study population consisted of 29 patients (frontal: n=17; posterior: n=12) and 29 matched controls. Phonological loop (letter and word spans, phonological store; rehearsal process), visuospatial sketchpad (visuospatial span) and the central executive (working memory span, dual task and updating process) were examined. The group comparison analysis showed impairment in the frontal group of: (i) verbal spans (P<0.03); (ii) with a deficit of the rehearsal process (P=0.006); (iii) visuospatial span (P=0.04); (iv) working memory span (P=0.001) that disappeared after controlling for verbal span and (v) running memory (P=0.05) unrelated to updating conditions. The clinical anatomical correlation study showed that impairment of the central executive depended on frontal and posterior lesion. Cognitive dysexecutive disorders were observed in 11/20 patients with central executive deficit and an inverse dissociation was observed in two patients. Receiver operating characteristic curve analysis indicated that cognitive dysexecutive disorders had the highest ability to discriminate frontal lesions (area under curve=0.844, 95% confidence interval: 0.74-0.95; P=0.0001; central executive impairment: area under curve=0.732, 95% confidence interval: 0.57-0.82; P=0.006). This study reveals that frontal lesions induce mild impairment of short-term memory associated with a deficit of the rehearsal process supporting the role of the frontal lobe in this process; the central executive depends on lesions in the frontal lobe and posterior regions accounting for its low frequency and the negative results of group studies. Finally, the frontal dysexecutive syndrome cannot be attributed to central executive impairment, although it may contribute to some dysexecutive disorders.

Apolipoprotein E (APOE) genotype has dissociable effects on memory and attentional-executive network function in Alzheimer's disease.

PubMed

Wolk, David A; Dickerson, Bradford C

2010-06-01

The epsilon4 allele of the apolipoprotein E (APOE) gene is the major genetic risk factor for Alzheimer's disease (AD), but limited work has suggested that APOE genotype may modulate disease phenotype. Carriers of the epsilon4 allele have been reported to have greater medial temporal lobe (MTL) pathology and poorer memory than noncarriers. Less attention has focused on whether there are domains of cognition and neuroanatomical regions more affected in noncarriers. Further, a major potential confound of prior in vivo studies is the possibility of different rates of clinical misdiagnosis for carriers vs. noncarriers. We compared phenotypic differences in cognition and topography of regional cortical atrophy of epsilon4 carriers (n = 67) vs. noncarriers (n = 24) with mild AD from the Alzheimer's Disease Neuroimaging Initiative, restricted to those with a cerebrospinal fluid (CSF) molecular profile consistent with AD. Between-group comparisons were made for psychometric tests and morphometric measures of cortical thickness and hippocampal volume. Carriers displayed significantly greater impairment on measures of memory retention, whereas noncarriers were more impaired on tests of working memory, executive control, and lexical access. Consistent with this cognitive dissociation, carriers exhibited greater MTL atrophy, whereas noncarriers had greater frontoparietal atrophy. Performance deficits in particular cognitive domains were associated with disproportionate regional brain atrophy within nodes of cortical networks thought to subserve these cognitive processes. These convergent cognitive and neuroanatomic findings in individuals with a CSF molecular profile consistent with AD support the hypothesis that APOE genotype modulates the clinical phenotype of AD through influence on specific large-scale brain networks.

Neural Correlates of Lyrical Improvisation: An fMRI Study of Freestyle Rap

PubMed Central

Liu, Siyuan; Chow, Ho Ming; Xu, Yisheng; Erkkinen, Michael G.; Swett, Katherine E.; Eagle, Michael W.; Rizik-Baer, Daniel A.; Braun, Allen R.

2012-01-01

The neural correlates of creativity are poorly understood. Freestyle rap provides a unique opportunity to study spontaneous lyrical improvisation, a multidimensional form of creativity at the interface of music and language. Here we use functional magnetic resonance imaging to characterize this process. Task contrast analyses indicate that improvised performance is characterized by dissociated activity in medial and dorsolateral prefrontal cortices, providing a context in which stimulus-independent behaviors may unfold in the absence of conscious monitoring and volitional control. Connectivity analyses reveal widespread improvisation-related correlations between medial prefrontal, cingulate motor, perisylvian cortices and amygdala, suggesting the emergence of a network linking motivation, language, affect and movement. Lyrical improvisation appears to be characterized by altered relationships between regions coupling intention and action, in which conventional executive control may be bypassed and motor control directed by cingulate motor mechanisms. These functional reorganizations may facilitate the initial improvisatory phase of creative behavior. PMID:23155479

Neural correlates of lyrical improvisation: an FMRI study of freestyle rap.

PubMed

Liu, Siyuan; Chow, Ho Ming; Xu, Yisheng; Erkkinen, Michael G; Swett, Katherine E; Eagle, Michael W; Rizik-Baer, Daniel A; Braun, Allen R

2012-01-01

The neural correlates of creativity are poorly understood. Freestyle rap provides a unique opportunity to study spontaneous lyrical improvisation, a multidimensional form of creativity at the interface of music and language. Here we use functional magnetic resonance imaging to characterize this process. Task contrast analyses indicate that improvised performance is characterized by dissociated activity in medial and dorsolateral prefrontal cortices, providing a context in which stimulus-independent behaviors may unfold in the absence of conscious monitoring and volitional control. Connectivity analyses reveal widespread improvisation-related correlations between medial prefrontal, cingulate motor, perisylvian cortices and amygdala, suggesting the emergence of a network linking motivation, language, affect and movement. Lyrical improvisation appears to be characterized by altered relationships between regions coupling intention and action, in which conventional executive control may be bypassed and motor control directed by cingulate motor mechanisms. These functional reorganizations may facilitate the initial improvisatory phase of creative behavior.

Not all sounds sound the same: Parkinson's disease affects differently emotion processing in music and in speech prosody.

PubMed

Lima, César F; Garrett, Carolina; Castro, São Luís

2013-01-01

Does emotion processing in music and speech prosody recruit common neurocognitive mechanisms? To examine this question, we implemented a cross-domain comparative design in Parkinson's disease (PD). Twenty-four patients and 25 controls performed emotion recognition tasks for music and spoken sentences. In music, patients had impaired recognition of happiness and peacefulness, and intact recognition of sadness and fear; this pattern was independent of general cognitive and perceptual abilities. In speech, patients had a small global impairment, which was significantly mediated by executive dysfunction. Hence, PD affected differently musical and prosodic emotions. This dissociation indicates that the mechanisms underlying the two domains are partly independent.

Executive-Attentional Uncertainty Responses by Rhesus Macaques ("Macaca mulatta")

ERIC Educational Resources Information Center

Smith, J. David; Coutinho, Mariana V. C.; Church, Barbara A.; Beran, Michael J.

2013-01-01

The uncertainty response has been influential in studies of human perception, and it is crucial in the growing research literature that explores animal metacognition. However, the uncertainty response's interpretation is still sharply debated. The authors sought to clarify this interpretation using the dissociative technique of cognitive loads…

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.

Dissociation in patients with dissociative seizures: relationships with trauma and seizure symptoms.

PubMed

Pick, S; Mellers, J D C; Goldstein, L H

2017-05-01

This study aimed to extend the current understanding of dissociative symptoms experienced by patients with dissociative (psychogenic, non-epileptic) seizures (DS), including psychological and somatoform types of symptomatology. An additional aim was to assess possible relationships between dissociation, traumatic experiences, post-traumatic symptoms and seizure manifestations in this group. A total of 40 patients with DS were compared with a healthy control group (n = 43), matched on relevant demographic characteristics. Participants completed several self-report questionnaires, including the Multiscale Dissociation Inventory (MDI), Somatoform Dissociation Questionnaire-20, Traumatic Experiences Checklist and the Post-Traumatic Diagnostic Scale. Measures of seizure symptoms and current emotional distress (Hospital Anxiety and Depression Scale) were also administered. The clinical group reported significantly more psychological and somatoform dissociative symptoms, trauma, perceived impact of trauma, and post-traumatic symptoms than controls. Some dissociative symptoms (i.e. MDI disengagement, MDI depersonalization, MDI derealization, MDI memory disturbance, and somatoform dissociation scores) were elevated even after controlling for emotional distress; MDI depersonalization scores correlated positively with trauma scores while seizure symptoms correlated with MDI depersonalization, derealization and identity dissociation scores. Exploratory analyses indicated that somatoform dissociation specifically mediated the relationship between reported sexual abuse and DS diagnosis, along with depressive symptoms. A range of psychological and somatoform dissociative symptoms, traumatic experiences and post-traumatic symptoms are elevated in patients with DS relative to healthy controls, and seem related to seizure manifestations. Further studies are needed to explore peri-ictal dissociative experiences in more detail.

Dissociative experiences in patients with epilepsy.

PubMed

Özdemir, Osman; Cilingir, Vedat; Özdemir, Pınar Güzel; Milanlioglu, Aysel; Hamamci, Mehmet; Yilmaz, Ekrem

2016-03-01

A few studies have explored dissociative experiences in epilepsy patients. We investigated dissociative experiences in patients with epilepsy using the dissociative experiences scale (DES). Ninety-eight patients with epilepsy and sixty healthy controls were enrolled in this study. A sociodemographic questionnaire and the Dissociative Experiences Scale (DES), Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI) were administered to the participants. The DES scores were significantly higher for the patients with epilepsy than the healthy individuals. The number of individuals with pathological dissociation (DES ≥ 30) was higher in the epilepsy group (n = 28) than in the control group (n = 8). Also, higher levels of dissociation were significantly associated with frequency of seizures, but were not associated with duration of epilepsy and age at onset of the disorder. These findings demonstrate that patients with epilepsy are more prone to dissociation than controls. The high rate of dissociative experiences among patients with epilepsy suggest that some epilepsy-related factors are present.

Aging and Executive Functioning: A Training Study on Focus-Switching

PubMed Central

Dorbath, Lara; Hasselhorn, Marcus; Titz, Cora

2011-01-01

Many studies suggest that age differences in a variety of cognitive tasks are due to age-related changes in executive control processes. However, not all executive control processes seem to be age-sensitive. Recently, Verhaeghen et al. (2005) described dissociable age effects in an executive control process responsible for the switching of representations between different functional units of working memory. This so called focus-switching process has two components: (1) the switching of representations from an activated part of long-term memory into a region of immediate access (focus of attention) and (2) the maintenance of representations outside the focus of attention. Age-related deficits occurred in maintaining representations outside the focus of attention, but were absent in switching representations into and out of the focus of attention (e.g., Dorbath and Titz, 2011). In the present study we applied a training approach to examine age-related differences in the trainability of maintenance and switching. We investigated 85 younger (age 19–35, M = 24.07, SD = 3.79) and 91 older (age 59–80, M = 66.27, SD = 4.75) adults using a continuous counting task in a pretest–training–posttest design. The participants were assigned to one of four training conditions differing in the demand to switch or to maintain. The results suggest the influence of training in both components of focus-switching for both, younger and older adults. However, age differences in the amount of training gains were observed. With respect to maintenance the results indicate a compensatory effect of training for older adults who improved their performance to the level of younger adults. With respect to switching, younger adults benefited more from training than older adults. Trainability is thus reduced in older adults with respect to switching, but not for maintenance. PMID:22016742

An Increase in Postural Load Facilitates an Anterior Shift of Processing Resources to Frontal Executive Function in a Postural-Suprapostural Task

PubMed Central

Huang, Cheng-Ya; Chang, Gwo-Ching; Tsai, Yi-Ying; Hwang, Ing-Shiou

2016-01-01

Increase in postural-demand resources does not necessarily degrade a concurrent motor task, according to the adaptive resource-sharing hypothesis of postural-suprapostural dual-tasking. This study investigated how brain networks are organized to optimize a suprapostural motor task when the postural load increases and shifts postural control into a less automatic process. Fourteen volunteers executed a designated force-matching task from a level surface (a relative automatic process in posture) and from a stabilometer board while maintaining balance at a target angle (a relatively controlled process in posture). Task performance of the postural and suprapostural tasks, synchronization likelihood (SL) of scalp EEG, and graph-theoretical metrics were assessed. Behavioral results showed that the accuracy and reaction time of force-matching from a stabilometer board were not affected, despite a significant increase in postural sway. However, force-matching in the stabilometer condition showed greater local and global efficiencies of the brain networks than force-matching in the level-surface condition. Force-matching from a stabilometer board was also associated with greater frontal cluster coefficients, greater mean SL of the frontal and sensorimotor areas, and smaller mean SL of the parietal-occipital cortex than force-matching from a level surface. The contrast of supra-threshold links in the upper alpha and beta bands between the two stance conditions validated load-induced facilitation of inter-regional connections between the frontal and sensorimotor areas, but that contrast also indicated connection suppression between the right frontal-temporal and the parietal-occipital areas for the stabilometer stance condition. In conclusion, an increase in stance difficulty alters the neurocognitive processes in executing a postural-suprapostural task. Suprapostural performance is not degraded by increase in postural load, due to (1) increased effectiveness of information transfer, (2) an anterior shift of processing resources toward frontal executive function, and (3) cortical dissociation of control hubs in the parietal-occipital cortex for neural economy. PMID:27594830

Dissociable contributions of motor-execution and action-observation to intramanual transfer.

PubMed

Hayes, Spencer J; Elliott, Digby; Andrew, Matthew; Roberts, James W; Bennett, Simon J

2012-09-01

We examined the hypothesis that different processes and representations are associated with the learning of a movement sequence through motor-execution and action-observation. Following a pre-test in which participants attempted to achieve an absolute, and relative, time goal in a sequential goal-directed aiming movement, participants received either physical or observational practice with feedback. Post-test performance indicated that motor-execution and action-observation participants learned equally well. Participants then transferred to conditions where the gain between the limb movements and their visual consequences were manipulated. Under both bigger and smaller transfer conditions, motor-execution and action-observation participants exhibited similar intramanual transfer of absolute timing. However, participants in the action-observation group exhibited superior transfer of relative timing than the motor-execution group. These findings suggest that learning via action-observation is underpinned by a visual-spatial representation, while learning via motor-execution depends more on specific force-time planning (feed forward) and afferent processing associated with sensorimotor feedback. These behavioural effects are discussed with reference to neural processes associated with striatum, cerebellum and motor cortical regions (pre-motor cortex; SMA; pre-SMA).

Multiple Deficits in ADHD: Executive Dysfunction, Delay Aversion, Reaction Time Variability, and Emotional Deficits

ERIC Educational Resources Information Center

Sjowall, Douglas; Roth, Linda; Lindqvist, Sofia; Thorell, Lisa B.

2013-01-01

Background: The notion that ADHD constitutes a heterogeneous disorder is well accepted. However, this study contributes with new important knowledge by examining independent effects of a large range of neuropsychological deficits. In addition, the study investigated whether deficits in emotional functioning constitute a dissociable component of…

Prospective memory after moderate-to-severe traumatic brain injury: a multinomial modeling approach.

PubMed

Pavawalla, Shital P; Schmitter-Edgecombe, Maureen; Smith, Rebekah E

2012-01-01

Prospective memory (PM), which can be understood as the processes involved in realizing a delayed intention, is consistently found to be impaired after a traumatic brain injury (TBI). Although PM can be empirically dissociated from retrospective memory, it inherently involves both a prospective component (i.e., remembering that an action needs to be carried out) and retrospective components (i.e., remembering what action needs to be executed and when). This study utilized a multinomial processing tree model to disentangle the prospective (that) and retrospective recognition (when) components underlying PM after moderate-to-severe TBI. Seventeen participants with moderate to severe TBI and 17 age- and education-matched control participants completed an event-based PM task that was embedded within an ongoing computer-based color-matching task. The multinomial processing tree modeling approach revealed a significant group difference in the prospective component, indicating that the control participants allocated greater preparatory attentional resources to the PM task compared to the TBI participants. Participants in the TBI group were also found to be significantly more impaired than controls in the when aspect of the retrospective component. These findings indicated that the TBI participants had greater difficulty allocating the necessary preparatory attentional resources to the PM task and greater difficulty discriminating between PM targets and nontargets during task execution, despite demonstrating intact posttest recall and/or recognition of the PM tasks and targets.

Working memory load and distraction: dissociable effects of visual maintenance and cognitive control.

PubMed

Konstantinou, Nikos; Beal, Eleanor; King, Jean-Remi; Lavie, Nilli

2014-10-01

We establish a new dissociation between the roles of working memory (WM) cognitive control and visual maintenance in selective attention as measured by the efficiency of distractor rejection. The extent to which focused selective attention can prevent distraction has been shown to critically depend on the level and type of load involved in the task. High perceptual load that consumes perceptual capacity leads to reduced distractor processing, whereas high WM load that reduces WM ability to exert priority-based executive cognitive control over the task results in increased distractor processing (e.g., Lavie, Trends in Cognitive Sciences, 9(2), 75-82, 2005). WM also serves to maintain task-relevant visual representations, and such visual maintenance is known to recruit the same sensory cortices as those involved in perception (e.g., Pasternak & Greenlee, Nature Reviews Neuroscience, 6(2), 97-107, 2005). These findings led us to hypothesize that loading WM with visual maintenance would reduce visual capacity involved in perception, thus resulting in reduced distractor processing-similar to perceptual load and opposite to WM cognitive control load. Distractor processing was assessed in a response competition task, presented during the memory interval (or during encoding; Experiment 1a) of a WM task. Loading visual maintenance or encoding by increased set size for a memory sample of shapes, colors, and locations led to reduced distractor response competition effects. In contrast, loading WM cognitive control with verbal rehearsal of a random letter set led to increased distractor effects. These findings confirm load theory predictions and provide a novel functional distinction between the roles of WM maintenance and cognitive control in selective attention.

Cognitive and neuropathologic correlates of Stroop Color-Word Test performance in Alzheimer's disease.

PubMed

Bondi, Mark W; Serody, Adam B; Chan, Agnes S; Eberson-Shumate, Sonja C; Delis, Dean C; Hansen, Lawrence A; Salmon, David P

2002-07-01

The Stroop Color-Word Test (SCWT; C. Golden, 1978) was examined in 59 patients with probable Alzheimer's disease (AD) and in 51 demographically comparable normal control (NC) participants. AD patients produced significantly larger Stroop interference effects than NC participants, and level of dementia severity significantly influenced SCWT performance. Principal-components analyses demonstrated a dissociation in the factor structure of the Stroop trials between NC participants and AD patients, suggesting that disruption of semantic knowledge and speeded verbal processing in AD may be a major contributor to impairment on the incongruent trial. Results of clinicopathologic correlations in an autopsy-confirmed AD subgroup further suggest the invocation of a broad network of integrated cortical regions and executive and language processes underlying successful SCWT performance.

Semantic memory and frontal executive function during transient global amnesia.

PubMed

Hodges, J R

1994-05-01

To assess semantic memory and frontal executive function, two patients underwent neuropsychological testing during transient global amnesia (TGA) and after an interval of 6-8 weeks. In spite of a profound deficit in anterograde verbal and non-verbal memory, semantic memory was normal, as judged by category fluency measures, picture naming, and picture-word and picture-picture matching, and reading ability was normal. Similarly, there were no deficits on a number of tests known to be sensitive to frontal executive dysfunction. A hexamethylpropyleneamine-oxime (HMPAO) single photon emission CT (SPECT) scan, obtained on one patient 24 hours post-TGA, showed focal left temporal lobe hypoperfusion which had resolved three months later. The observed dissociation between episodic and semantic memory is discussed in the light of contemporary cognitive theories of memory organisation.

Unity and diversity of executive functions: Individual differences as a window on cognitive structure.

PubMed

Friedman, Naomi P; Miyake, Akira

2017-01-01

Executive functions (EFs) are high-level cognitive processes, often associated with the frontal lobes, that control lower level processes in the service of goal-directed behavior. They include abilities such as response inhibition, interference control, working memory updating, and set shifting. EFs show a general pattern of shared but distinct functions, a pattern described as "unity and diversity". We review studies of EF unity and diversity at the behavioral and genetic levels, focusing on studies of normal individual differences and what they reveal about the functional organization of these cognitive abilities. In particular, we review evidence that across multiple ages and populations, commonly studied EFs (a) are robustly correlated but separable when measured with latent variables; (b) are not the same as general intelligence or g; (c) are highly heritable at the latent level and seemingly also highly polygenic; and (d) activate both common and specific neural areas and can be linked to individual differences in neural activation, volume, and connectivity. We highlight how considering individual differences at the behavioral and neural levels can add considerable insight to the investigation of the functional organization of the brain, and conclude with some key points about individual differences to consider when interpreting neuropsychological patterns of dissociation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dissociative Symptoms and Reported Trauma Among Patients with Spirit Possession and Matched Healthy Controls in Uganda

PubMed Central

Nijenhuis, Ellert; Komproe, Ivan H.; Gernaat, Hajo B. P. E.; de Jong, Joop T.

2010-01-01

Spirit possession is a common, worldwide phenomenon with dissociative features. Studies in Europe and the United States have revealed associations among psychoform and somatoform dissociation and (reported) potential traumatic events. The aim of this study was to explore the relationships among spirit possession, dissociative symptoms and reported potentially traumatizing events in Uganda. One hundred nineteen persons with spirit possession, diagnosed by traditional healers, were compared to a matched control group of 71 nonpossessed persons. Assessments included demographic items and measures of dissociation and potentially traumatizing events. Compared to the nonpossessed group, the possessed group reported more severe psychoform dissociation and somatoform dissociation and more potentially traumatizing events. The associations between these events and both types of dissociation were significant. Yet, consistent with the cultural perception of dissociative symptoms, the participants subjectively did not associate dissociative symptoms with potentially traumatizing events. In conclusion, spirit possession deserves more interest as a possible idiom of distress and a culture-specific expression of dissociation related to potential traumatizing events. PMID:20401630

Dissociation of long-term verbal memory and fronto-executive impairment in first-episode psychosis

PubMed Central

Leeson, V. C.; Robbins, T. W.; Franklin, C.; Harrison, M.; Harrison, I.; Ron, M. A.; Barnes, T. R. E.; Joyce, E. M.

2009-01-01

Background Verbal memory is frequently and severely affected in schizophrenia and has been implicated as a mediator of poor clinical outcome. Whereas encoding deficits are well demonstrated, it is unclear whether retention is impaired. This distinction is important because accelerated forgetting implies impaired consolidation attributable to medial temporal lobe (MTL) dysfunction whereas impaired encoding and retrieval implicates involvement of prefrontal cortex. Method We assessed a group of healthy volunteers (n=97) and pre-morbid IQ- and sex-matched first-episode psychosis patients (n=97), the majority of whom developed schizophrenia. We compared performance of verbal learning and recall with measures of visuospatial working memory, planning and attentional set-shifting, and also current IQ. Results All measures of performance, including verbal memory retention, a memory savings score that accounted for learning impairments, were significantly impaired in the schizophrenia group. The difference between groups for delayed recall remained even after the influence of learning and recall was accounted for. Factor analyses showed that, in patients, all variables except verbal memory retention loaded on a single factor, whereas in controls verbal memory and fronto-executive measures were separable. Conclusions The results suggest that IQ, executive function and verbal learning deficits in schizophrenia may reflect a common abnormality of information processing in prefrontal cortex rather than specific impairments in different cognitive domains. Verbal memory retention impairments, however, may have a different aetiology. PMID:19419594

REWARD/PUNISHMENT REVERSAL LEARNING IN OLDER SUICIDE ATTEMPTERS

PubMed Central

Dombrovski, Alexandre Y.; Clark, Luke; Siegle, Greg J.; Butters, Meryl A.; Ichikawa, Naho; Sahakian, Barbara; Szanto, Katalin

2011-01-01

Objective Suicide rates are very high in old age, and the contribution of cognitive risk factors remains poorly understood. Suicide may be viewed as an outcome of an altered decision process. We hypothesized that impairment in a component of affective decision-making – reward/punishment-based learning – is associated with attempted suicide in late-life depression. We expected that suicide attempters would discount past reward/punishment history, focusing excessively on the most recent rewards and punishments. Further, we hypothesized that this impairment could be dissociated from executive abilities such as forward planning. Method We assessed reward/punishment-based learning using the Probabilistic Reversal Learning task in 65 individuals aged 60 and older: suicide attempters, suicide ideators, non-suicidal depressed elderly, and non-depressed controls. We used a reinforcement learning computational model to decompose reward/punishment processing over time. The Stockings of Cambridge test served as a control measure of executive function. Results Suicide attempters but not suicide ideators showed impaired probabilistic reversal learning compared to both non-suicidal depressed elderly and to non-depressed controls, after controlling for effects of education, global cognitive function, and substance use. Model-based analyses revealed that suicide attempters discounted previous history to a higher degree, compared to controls, basing their choice largely on reward/punishment received on the last trial. Groups did not differ in their performance on the Stockings of Cambridge. Conclusions Older suicide attempters display impaired reward/punishment-based learning. We propose a hypothesis that older suicide attempters make overly present-focused decisions, ignoring past experiences. Modification of this ‘myopia for the past’ may have therapeutic potential. PMID:20231320

Dissociated control as a signature of typological variability in high hypnotic suggestibility.

PubMed

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

2011-09-01

This study tested the prediction that dissociative tendencies modulate the impact of a hypnotic induction on cognitive control in different subtypes of highly suggestible individuals. Low suggestible (LS), low dissociative highly suggestible (LDHS), and high dissociative highly suggestible (HDHS) participants completed the Stroop color-naming task in control and hypnosis conditions. The magnitude of conflict adaptation (faster response times on incongruent trials preceded by an incongruent trial than those preceded by a congruent trial) was used as a measure of cognitive control. LS and LDHS participants displayed marginally superior up-regulation of cognitive control following a hypnotic induction, whereas HDHS participants' performance declined. These findings indicate that dissociative tendencies modulate the influence of a hypnotic induction on cognitive control in high hypnotic suggestibility and suggest that HS individuals are comprised of distinct subtypes with dissimilar cognitive profiles. Copyright © 2010 Elsevier Inc. All rights reserved.

Age-related changes in the ease of dynamical transitions in human brain activity.

PubMed

Ezaki, Takahiro; Sakaki, Michiko; Watanabe, Takamitsu; Masuda, Naoki

2018-06-01

Executive functions, a set of cognitive processes that enable flexible behavioral control, are known to decay with aging. Because such complex mental functions are considered to rely on the dynamic coordination of functionally different neural systems, the age-related decline in executive functions should be underpinned by alteration of large-scale neural dynamics. However, the effects of age on brain dynamics have not been firmly formulated. Here, we investigate such age-related changes in brain dynamics by applying "energy landscape analysis" to publicly available functional magnetic resonance imaging data from healthy younger and older human adults. We quantified the ease of dynamical transitions between different major patterns of brain activity, and estimated it for the default mode network (DMN) and the cingulo-opercular network (CON) separately. We found that the two age groups shared qualitatively the same trajectories of brain dynamics in both the DMN and CON. However, in both of networks, the ease of transitions was significantly smaller in the older than the younger group. Moreover, the ease of transitions was associated with the performance in executive function tasks in a doubly dissociated manner: for the younger adults, the ability of executive functions was mainly correlated with the ease of transitions in the CON, whereas that for the older adults was specifically associated with the ease of transitions in the DMN. These results provide direct biological evidence for age-related changes in macroscopic brain dynamics and suggest that such neural dynamics play key roles when individuals carry out cognitively demanding tasks. © 2018 Wiley Periodicals, Inc.

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.

Dissociation of verbal working memory system components using a delayed serial recall task.

PubMed

Chein, J M; Fiez, J A

2001-11-01

Functional magnetic resonance imaging (fMRI) was used to investigate the neural substrates of component processes in verbal working memory. Based on behavioral research using manipulations of verbal stimulus type to dissociate storage, rehearsal, and executive components of verbal working memory, we designed a delayed serial recall task requiring subjects to encode, maintain, and overtly recall sets of verbal items for which phonological similarity, articulatory length, and lexical status were manipulated. By using a task with temporally extended trials, we were able to exploit the temporal resolution afforded by fMRI to partially isolate neural contributions to encoding, maintenance, and retrieval stages of task performance. Several regions commonly associated with maintenance, including supplementary motor, premotor, and inferior frontal areas, were found to be active across all three trial stages. Additionally, we found that left inferior frontal and supplementary motor regions showed patterns of stimulus and temporal sensitivity implicating them in distinct aspects of articulatory rehearsal, while no regions showed a pattern of sensitivity consistent with a role in phonological storage. Regional modulation by task difficulty was further investigated as a measure of executive processing. We interpret our findings as they relate to notions about the cognitive architecture underlying verbal working memory performance.

Non-visual spatial tasks reveal increased interactions with stance postural control.

PubMed

Woollacott, Marjorie; Vander Velde, Timothy

2008-05-07

The current investigation aimed to contrast the level and quality of dual-task interactions resulting from the combined performance of a challenging primary postural task and three specific, yet categorically dissociated, secondary central executive tasks. Experiments determined the extent to which modality (visual vs. auditory) and code (non-spatial vs. spatial) specific cognitive resources contributed to postural interference in young adults (n=9) in a dual-task setting. We hypothesized that the different forms of executive n-back task processing employed (visual-object, auditory-object and auditory-spatial) would display contrasting levels of interactions with tandem Romberg stance postural control, and that interactions within the spatial domain would be revealed as most vulnerable to dual-task interactions. Across all cognitive tasks employed, including auditory-object (aOBJ), auditory-spatial (aSPA), and visual-object (vOBJ) tasks, increasing n-back task complexity produced correlated increases in verbal reaction time measures. Increasing cognitive task complexity also resulted in consistent decreases in judgment accuracy. Postural performance was significantly influenced by the type of cognitive loading delivered. At comparable levels of cognitive task difficulty (n-back demands and accuracy judgments) the performance of challenging auditory-spatial tasks produced significantly greater levels of postural sway than either the auditory-object or visual-object based tasks. These results suggest that it is the employment of limited non-visual spatially based coding resources that may underlie previously observed visual dual-task interference effects with stance postural control in healthy young adults.

Malingering dissociative identity disorder: objective and projective assessment.

PubMed

Labott, Susan M; Wallach, Heather R

2002-04-01

Verification of dissociative identity disorder presents challenges given the complex nature of the illness. This study addressed the concern that this disorder can be successfully malingered on objective and projective psychological tests. 50 undergraduate women were assigned to a Malingering or a Control condition, then completed the Rorschach Inkblot Test and the Dissociative Experiences Scale II. The Malingering group were asked to simulate dissociative identity disorder; controls received instructions to answer all materials honestly. Analysis indicated that malingerers were significantly more likely to endorse dissociative experiences on the Dissociative Experiences Scale II in the range common to patients with diagnosed dissociative identity disorder. However, on the Rorschach there were no significant differences between the two groups. Results suggest that the assessment of dissociative identity disorder requires a multifaceted approach with both objective and projective assessment tools. Research is needed to assess these issues in clinical populations.

Memories of attachment hamper EEG cortical connectivity in dissociative patients.

PubMed

Farina, Benedetto; Speranza, Anna Maria; Dittoni, Serena; Gnoni, Valentina; Trentini, Cristina; Vergano, Carola Maggiora; Liotti, Giovanni; Brunetti, Riccardo; Testani, Elisa; Della Marca, Giacomo

2014-08-01

In this study, we evaluated cortical connectivity modifications by electroencephalography (EEG) lagged coherence analysis, in subjects with dissociative disorders and in controls, after retrieval of attachment memories. We asked thirteen patients with dissociative disorders and thirteen age- and sex-matched healthy controls to retrieve personal attachment-related autobiographical memories through adult attachment interviews (AAI). EEG was recorded in the closed eyes resting state before and after the AAI. EEG lagged coherence before and after AAI was compared in all subjects. In the control group, memories of attachment promoted a widespread increase in EEG connectivity, in particular in the high-frequency EEG bands. Compared to controls, dissociative patients did not show an increase in EEG connectivity after the AAI. Conclusions: These results shed light on the neurophysiology of the disintegrative effect of retrieval of traumatic attachment memories in dissociative patients.

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.

Prospective Memory Impairments in Alzheimer's Disease and Behavioral Variant Frontotemporal Dementia: Clinical and Neural Correlates.

PubMed

Dermody, Nadene; Hornberger, Michael; Piguet, Olivier; Hodges, John R; Irish, Muireann

2016-01-01

Prospective memory (PM) refers to a future-oriented form of memory in which the individual must remember to execute an intended action either at a future point in time (Time-based) or in response to a specific event (Event-based). Lapses in PM are commonly exhibited in neurodegenerative disorders including Alzheimer's disease (AD) and frontotemporal dementia (FTD), however, the neurocognitive mechanisms driving these deficits remain unknown. To investigate the clinical and neural correlates of Time- and Event-based PM disruption in AD and the behavioral-variant FTD (bvFTD). Twelve AD, 12 bvFTD, and 12 healthy older Control participants completed a modified version of the Cambridge Prospective Memory test, which examines Time- and Event-based aspects of PM. All participants completed a standard neuropsychological assessment and underwent whole-brain structural MRI. AD and bvFTD patients displayed striking impairments across Time- and Event-based PM relative to Controls, however, Time-based PM was disproportionately affected in the AD group. Episodic memory dysfunction and hippocampal atrophy were found to correlate strongly with PM integrity in both patient groups, however, dissociable neural substrates were also evident for PM performance across dementia syndromes. Our study reveals the multifaceted nature of PM dysfunction in neurodegenerative disorders, and suggests common and dissociable neurocognitive mechanisms, which subtend these deficits in each patient group. Future studies of PM disturbance in dementia syndromes will be crucial for the development of successful interventions to improve functional independence in the patient's daily life.

Lateral Prefrontal Cortex Subregions Make Dissociable Contributions during Fluid Reasoning

PubMed Central

Thompson, Russell; Duncan, John; Owen, Adrian M.

2011-01-01

Reasoning is a key component of adaptable “executive” behavior and is known to depend on a network of frontal and parietal brain regions. However, the mechanisms by which this network supports reasoning and adaptable behavior remain poorly defined. Here, we examine the relationship between reasoning, executive control, and frontoparietal function in a series of nonverbal reasoning experiments. Our results demonstrate that, in accordance with previous studies, a network of frontal and parietal brain regions is recruited during reasoning. Our results also reveal that this network can be fractionated according to how different subregions respond when distinct reasoning demands are manipulated. While increased rule complexity modulates activity within a right lateralized network including the middle frontal gyrus and the superior parietal cortex, analogical reasoning demand—or the requirement to remap rules on to novel features—recruits the left inferior rostrolateral prefrontal cortex and the lateral occipital complex. In contrast, the posterior extent of the inferior frontal gyrus, associated with simpler executive demands, is not differentially sensitive to rule complexity or analogical demand. These findings accord well with the hypothesis that different reasoning demands are supported by different frontal and parietal subregions. PMID:20483908

When action is not enough: tool-use reveals tactile-dependent access to Body Schema.

PubMed

Cardinali, L; Brozzoli, C; Urquizar, C; Salemme, R; Roy, A C; Farnè, A

2011-11-01

Proper motor control of our own body implies a reliable representation of body parts. This information is supposed to be stored in the Body Schema (BS), a body representation that appears separate from a more perceptual body representation, the Body Image (BI). The dissociation between BS for action and BI for perception, originally based on neuropsychological evidence, has recently become the focus of behavioural studies in physiological conditions. By inducing the rubber hand illusion in healthy participants, Kammers et al. (2009) showed perceptual changes attributable to the BI to which the BS, as indexed via motor tasks, was immune. To more definitively support the existence of dissociable body representations in physiological conditions, here we tested for the opposite dissociation, namely, whether a tool-use paradigm would induce a functional update of the BS (via a motor localization task) without affecting the BI (via a perceptual localization task). Healthy subjects were required to localize three anatomical landmarks on their right arm, before and after using the same arm to control a tool. In addition to this classical task-dependency approach, we assessed whether preferential access to the BS could also depend upon the way positional information about forearm targets is provided, to subsequently execute the same task. To this aim, participants performed either verbally or tactually driven versions of the motor and perceptual localization tasks. Results showed that both the motor and perceptual tasks were sensitive to the update of the forearm representation, but only when the localization task (perceptual or motor) was driven by a tactile input. This pattern reveals that the motor output is not sufficient per se, but has to be coupled with tactually mediated information to guarantee access to the BS. These findings shade a new light on the action-perception models of body representations and underlie how functional plasticity may be a useful tool to clarify their operational definition. Copyright © 2011 Elsevier Ltd. All rights reserved.

Action history influences subsequent movement via two distinct processes

PubMed Central

Poh, Eugene; de Rugy, Aymar

2017-01-01

The characteristics of goal-directed actions tend to resemble those of previously executed actions, but it is unclear whether such effects depend strictly on action history, or also reflect context-dependent processes related to predictive motor planning. Here we manipulated the time available to initiate movements after a target was specified, and studied the effects of predictable movement sequences, to systematically dissociate effects of the most recently executed movement from the movement required next. We found that directional biases due to recent movement history strongly depend upon movement preparation time, suggesting an important contribution from predictive planning. However predictive biases co-exist with an independent source of bias that depends only on recent movement history. The results indicate that past experience influences movement execution through a combination of temporally-stable processes that are strictly use-dependent, and dynamically-evolving and context-dependent processes that reflect prediction of future actions. PMID:29058670

Neural priming in human frontal cortex: multiple forms of learning reduce demands on the prefrontal executive system.

PubMed

Race, Elizabeth A; Shanker, Shanti; Wagner, Anthony D

2009-09-01

Past experience is hypothesized to reduce computational demands in PFC by providing bottom-up predictive information that informs subsequent stimulus-action mapping. The present fMRI study measured cortical activity reductions ("neural priming"/"repetition suppression") during repeated stimulus classification to investigate the mechanisms through which learning from the past decreases demands on the prefrontal executive system. Manipulation of learning at three levels of representation-stimulus, decision, and response-revealed dissociable neural priming effects in distinct frontotemporal regions, supporting a multiprocess model of neural priming. Critically, three distinct patterns of neural priming were identified in lateral frontal cortex, indicating that frontal computational demands are reduced by three forms of learning: (a) cortical tuning of stimulus-specific representations, (b) retrieval of learned stimulus-decision mappings, and (c) retrieval of learned stimulus-response mappings. The topographic distribution of these neural priming effects suggests a rostrocaudal organization of executive function in lateral frontal cortex.

Syllogistic Reasoning and Belief-Bias Inhibition in School Children: Evidence from a Negative Priming Paradigm

ERIC Educational Resources Information Center

Moutier, Sylvain; Plagne-Cayeux, Stephanie; Melot, Anne-Marie; Houde, Olivier

2006-01-01

Research on deductive reasoning in adolescents and adults has shown that errors in deductive logic are not necessarily due to a lack of logical ability but can stem from an executive failure to inhibit biases. Few studies have examined this dissociation in children. Here, we used a negative priming paradigm with 64 children (8-10 years old) to…

Recollection deficiencies in patients with major depressive disorder.

PubMed

Drakeford, Justine L; Edelstyn, Nicola M J; Oyebode, Femi; Srivastava, Shrikant; Calthorpe, William R; Mukherjee, Tirthankar

2010-02-28

Neuropsychological research suggests that recognition memory (RM) and recall memory are impaired in patients with a major depressive disorder or a dysphoric mood state. This study examines the proposal that abnormalities in recollection (a form of recall) result from a breakdown in frontal strategic memory processes involved in encoding and retrieval, and executive functions linked to reality monitoring, planning, problem-solving, reasoning and decision-making. We investigated two predictions arising from this theory. Firstly, patients diagnosed with a major depressive disorder (MDD) will display a dissociation between (deficient) recollection and (preserved) familiarity. Secondly, if recollection impairments are indicative of a breakdown in prefrontal strategic memory processes which are dependent, at least in part, on executive processes, then an explicit correlational approach predicts that recollection will be positively associated with the severity of executive dysfunction in MDD patients. The remember/know paradigm was used to investigate RM for words and neutral faces in 16 MDD patients and 16 healthy volunteers, matched for age, gender and estimates of premorbid IQ. Measures of executive function included working memory, reasoning and decision-making. Applying the Dual Process Signal Detection interpretation of the remember/know data, the MDD group displayed significant impairments in RM and recollection rates for both verbal and neutral facial memoranda. In contrast, familiarity-aware rates were preserved. There was no evidence of executive dysfunction in the patient group, and little evidence that recollection rates correlated with executive function. Furthermore, a single process signal detection approach suggested that the MDD patients displayed a reduction in sensitivity for RM and remember rates but not know responses. The criteria for detecting studied from unstudied items, and remembering from knowing, were the same in both patient and healthy control groups. Taken together, these findings are consistent with the view that MDD is marked by a decline in RM, which is underpinned by an impairment in recollection rather than familiarity processes. The extent to which the recollection deficiencies arise from disruption of strategic memory and executive processes requires further investigation. 2008 Elsevier Ireland Ltd. All rights reserved.

The neuropsychopharmacology of fronto-executive function: monoaminergic modulation.

PubMed

Robbins, T W; Arnsten, A F T

2009-01-01

We review the modulatory effects of the catecholamine neurotransmitters noradrenaline and dopamine on prefrontal cortical function. The effects of pharmacologic manipulations of these systems, sometimes in comparison with the indoleamine serotonin (5-HT), on performance on a variety of tasks that tap working memory, attentional-set formation and shifting, reversal learning, and response inhibition are compared in rodents, nonhuman primates, and humans using, in a behavioral context, several techniques ranging from microiontophoresis and single-cell electrophysiological recording to pharmacologic functional magnetic resonance imaging. Dissociable effects of drugs and neurotoxins affecting these monoamine systems suggest new ways of conceptualizing state-dependent fronto-executive functions, with implications for understanding the molecular genetic basis of mental illness and its treatment.

Automatic and Controlled Semantic Retrieval: TMS Reveals Distinct Contributions of Posterior Middle Temporal Gyrus and Angular Gyrus

PubMed Central

Davey, James; Cornelissen, Piers L.; Thompson, Hannah E.; Sonkusare, Saurabh; Hallam, Glyn; Smallwood, Jonathan

2015-01-01

Semantic retrieval involves both (1) automatic spreading activation between highly related concepts and (2) executive control processes that tailor this activation to suit the current context or goals. Two structures in left temporoparietal cortex, angular gyrus (AG) and posterior middle temporal gyrus (pMTG), are thought to be crucial to semantic retrieval and are often recruited together during semantic tasks; however, they show strikingly different patterns of functional connectivity at rest (coupling with the “default mode network” and “frontoparietal control system,” respectively). Here, transcranial magnetic stimulation (TMS) was used to establish a causal yet dissociable role for these sites in semantic cognition in human volunteers. TMS to AG disrupted thematic judgments particularly when the link between probe and target was strong (e.g., a picture of an Alsatian with a bone), and impaired the identification of objects at a specific but not a superordinate level (for the verbal label “Alsatian” not “animal”). In contrast, TMS to pMTG disrupted thematic judgments for weak but not strong associations (e.g., a picture of an Alsatian with razor wire), and impaired identity matching for both superordinate and specific-level labels. Thus, stimulation to AG interfered with the automatic retrieval of specific concepts from the semantic store while stimulation of pMTG impaired semantic cognition when there was a requirement to flexibly shape conceptual activation in line with the task requirements. These results demonstrate that AG and pMTG make a dissociable contribution to automatic and controlled aspects of semantic retrieval. SIGNIFICANCE STATEMENT We demonstrate a novel functional dissociation between the angular gyrus (AG) and posterior middle temporal gyrus (pMTG) in conceptual processing. These sites are often coactivated during neuroimaging studies using semantic tasks, but their individual contributions are unclear. Using transcranial magnetic stimulation and tasks designed to assess different aspects of semantics (item identity and thematic matching), we tested two alternative theoretical accounts. Neither site showed the pattern expected for a “thematic hub” (i.e., a site storing associations between concepts) since stimulation disrupted both tasks. Instead, the data indicated that pMTG contributes to the controlled retrieval of conceptual knowledge, while AG is critical for the efficient automatic retrieval of specific semantic information. PMID:26586812

Forest, Trees, Dynamics: Results from a Novel Wisconsin Card Sorting Test Variant Protocol for Studying Global-Local Attention and Complex Cognitive Processes

PubMed Central

Cowley, Benjamin; Lukander, Kristian

2016-01-01

Background: Recognition of objects and their context relies heavily on the integrated functioning of global and local visual processing. In a realistic setting such as work, this processing becomes a sustained activity, implying a consequent interaction with executive functions. Motivation: There have been many studies of either global-local attention or executive functions; however it is relatively novel to combine these processes to study a more ecological form of attention. We aim to explore the phenomenon of global-local processing during a task requiring sustained attention and working memory. Methods: We develop and test a novel protocol for global-local dissociation, with task structure including phases of divided (“rule search”) and selective (“rule found”) attention, based on the Wisconsin Card Sorting Task (WCST). We test it in a laboratory study with 25 participants, and report on behavior measures (physiological data was also gathered, but not reported here). We develop novel stimuli with more naturalistic levels of information and noise, based primarily on face photographs, with consequently more ecological validity. Results: We report behavioral results indicating that sustained difficulty when participants test their hypotheses impacts matching-task performance, and diminishes the global precedence effect. Results also show a dissociation between subjectively experienced difficulty and objective dimension of performance, and establish the internal validity of the protocol. Contribution: We contribute an advance in the state of the art for testing global-local attention processes in concert with complex cognition. With three results we establish a connection between global-local dissociation and aspects of complex cognition. Our protocol also improves ecological validity and opens options for testing additional interactions in future work. PMID:26941689

Confabulation behavior and false memories in Korsakoff's syndrome: role of source memory and executive functioning.

PubMed

Kessels, Roy P C; Kortrijk, Hans E; Wester, Arie J; Nys, Gudrun M S

2008-04-01

Confabulation behavior is common in patients with Korsakoff's syndrome. A distinction can be made between spontaneous and provoked confabulations, which may have different underlying cognitive mechanisms. Provoked confabulations may be related to intrusions on memory tests, whereas spontaneous confabulations may be due to executive dysfunction or a source memory deficit. In 19 chronic Korsakoff patients, spontaneous confabulations were quantified by third-party rating (Likert scale). Provoked confabulations were assessed using the Dalla Barba Confabulation Battery. Furthermore, assessment of executive function was performed using an extensive neuropsychological battery. False memories (i.e. intrusions) and source memory were measured using twoparallelversions of a word-list learning paradigm (a modification of the Rey Auditory Verbal Learning Test). There were deficits in source memory, in which patients incorrectly assigned previously learned words to an incorrect word list. Also, Korsakoff patients had extensive executive deficits, but no relationship between the severity of these deficits and the severity of confabulation or intrusions on a memory task was found. The present findings provide evidence for a dissociation between spontaneous confabulation, provoked confabulation and false memories.

Determinants to trigger memory reconsolidation: The role of retrieval and updating information.

PubMed

Rodriguez-Ortiz, Carlos J; Bermúdez-Rattoni, Federico

2017-07-01

Long-term memories can undergo destabilization/restabilization processes, collectively called reconsolidation. However, the parameters that trigger memory reconsolidation are poorly understood and are a matter of intense investigation. Particularly, memory retrieval is widely held as requisite to initiate reconsolidation. This assumption makes sense since only relevant cues will induce reconsolidation of a specific memory. However, recent studies show that pharmacological inhibition of retrieval does not avoid memory from undergoing reconsolidation, indicating that memory reconsolidation occurs through a process that can be dissociated from retrieval. We propose that retrieval is not a unitary process but has two dissociable components; one leading to the expression of memory and the other to reconsolidation, referred herein as executer and integrator respectively. The executer would lead to the behavioral expression of the memory. This component would be the one disrupted on the studies that show reconsolidation independence from retrieval. The integrator would deal with reconsolidation. This component of retrieval would lead to long-term memory destabilization when specific conditions are met. We think that an important number of reports are consistent with the hypothesis that reconsolidation is only initiated when updating information is acquired. We suggest that the integrator would initiate reconsolidation to integrate updating information into long-term memory. Copyright © 2016 Elsevier Inc. All rights reserved.

Electrostatic control of DNA intersegmental translocation by the ETS transcription factor ETV6.

PubMed

Vo, Tam; Wang, Shuo; Poon, Gregory M K; Wilson, W David

2017-08-11

To find their DNA target sites in complex solution environments containing excess heterogeneous DNA, sequence-specific DNA-binding proteins execute various translocation mechanisms known collectively as facilitated diffusion. For proteins harboring a single DNA contact surface, long-range translocation occurs by jumping between widely spaced DNA segments. We have configured biosensor-based surface plasmon resonance to directly measure the affinity and kinetics of this intersegmental jumping by the ETS-family transcription factor ETS variant 6 (ETV6). To isolate intersegmental target binding in a functionally defined manner, we pre-equilibrated ETV6 with excess salmon sperm DNA, a heterogeneous polymer, before exposing the nonspecifically bound protein to immobilized oligomeric DNA harboring a high-affinity ETV6 site. In this way, the mechanism of ETV6-target association could be toggled electrostatically through varying NaCl concentration in the bulk solution. Direct measurements of association and dissociation kinetics of the site-specific complex indicated that 1) freely diffusive binding by ETV6 proceeds through a nonspecific-like intermediate, 2) intersegmental jumping is rate-limited by dissociation from the nonspecific polymer, and 3) dissociation of the specific complex is independent of the history of complex formation. These results show that target searches by proteins with an ETS domain, such as ETV6, whose single DNA-binding domain cannot contact both source and destination sites simultaneously, are nonetheless strongly modulated by intersegmental jumping in heterogeneous site environments. Our findings establish biosensors as a general technique for directly and specifically measuring target site search by DNA-binding proteins via intersegmental translocation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Dissociable contributions of the orbitofrontal and infralimbic cortex to pavlovian autoshaping and discrimination reversal learning: further evidence for the functional heterogeneity of the rodent frontal cortex.

PubMed

Chudasama, Y; Robbins, Trevor W

2003-09-24

To examine possible heterogeneity of function within the ventral regions of the rodent frontal cortex, the present study compared the effects of excitotoxic lesions of the orbitofrontal cortex (OFC) and the infralimbic cortex (ILC) on pavlovian autoshaping and discrimination reversal learning. During the pavlovian autoshaping task, in which rats learn to approach a stimulus predictive of reward [conditional stimulus (CS+)], only the OFC group failed to acquire discriminated approach but was unimpaired when preoperatively trained. In the visual discrimination learning and reversal task, rats were initially required to discriminate a stimulus positively associated with reward. There was no effect of either OFC or ILC lesions on discrimination learning. When the stimulus-reward contingencies were reversed, both groups of animals committed more errors, but only the OFC-lesioned animals were unable to suppress the previously rewarded stimulus-reward association, committing more "stimulus perseverative" errors. In contrast, the ILC group showed a pattern of errors that was more attributable to "learning" than perseveration. These findings suggest two types of dissociation between the effects of OFC and ILC lesions: (1) OFC lesions impaired the learning processes implicated in pavlovian autoshaping but not instrumental simultaneous discrimination learning, whereas ILC lesions were unimpaired at autoshaping and their reversal learning deficit did not reflect perseveration, and (2) OFC lesions induced perseverative responding in reversal learning but did not disinhibit responses to pavlovian CS-. In contrast, the ILC lesion had no effect on response inhibitory control in either of these settings. The findings are discussed in the context of dissociable executive functions in ventral sectors of the rat prefrontal cortex.

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.

Effects of smoking history on selective attention in schizophrenia.

PubMed

Hahn, Constanze; Hahn, Eric; Dettling, Michael; Güntürkün, Onur; Ta, Thi Minh Tam; Neuhaus, Andres H

2012-03-01

Smoking prevalence is highly elevated in schizophrenia compared to the general population and to other psychiatric populations. Evidence suggests that smoking may lead to improvements of schizophrenia-associated attention deficits; however, large-scale studies on this important issue are scarce. We examined whether sustained, selective, and executive attention processes are differentially modulated by long-term nicotine consumption in 104 schizophrenia patients and 104 carefully matched healthy controls. A significant interaction of 'smoking status' × 'diagnostic group' was obtained for the domain of selective attention. Smoking was significantly associated with a detrimental conflict effect in controls, while the opposite effect was revealed for schizophrenia patients. Likewise, a positive correlation between a cumulative measure of nicotine consumption and conflict effect in controls and a negative correlation in patients were found. These results provide evidence for specific directional effects of smoking on conflict processing that critically dissociate with diagnosis. The data supports the self-medication hypothesis of smoking in schizophrenia and suggests selective attention as a specific cognitive domain targeted by nicotine consumption. A potential mechanistic model explaining these findings is discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Brain mechanisms underlying the effects of aging on different aspects of selective attention.

PubMed

Geerligs, Linda; Saliasi, Emi; Maurits, Natasha M; Renken, Remco J; Lorist, Monicque M

2014-05-01

The ability to suppress irrelevant information declines with age, while the ability to enhance relevant information remains largely intact. We examined mechanisms behind this dissociation in an fMRI study, using a selective attention task in which relevant and irrelevant information appeared simultaneously. Slowing of response times due to distraction by irrelevant targets was larger in older than younger participants. Increased distraction was related to larger increases in activity and connectivity in areas of the dorsal attention network, indicating a more pronounced (re-)orientation of attention. The decreases in accuracy in target compared to nontarget trials were smaller in older compared to younger participants. In older adults we found increased recruitment of areas in the fronto-parietal control network (FPCN) during target detection. Moreover, older adults showed increased connectivity between the FPCN, supporting cognitive control, and somatomotor areas implicated in response selection and execution. This connectivity increase was related to improved target detection, suggesting that older adults engage additional cognitive control, which might enable the observed intact performance in detecting and responding to target stimuli. Copyright © 2014 Elsevier Inc. All rights reserved.

Dissociating Effects of Global SWS Disruption and Healthy Aging on Waking Performance and Daytime Sleepiness

PubMed Central

Groeger, John A.; Stanley, Neil; Deacon, Stephen; Dijk, Derk-Jan

2014-01-01

Study Objective: To contrast the effects of slow wave sleep (SWS) disruption and age on daytime functioning. Design: Daytime functioning was contrasted in three age cohorts, across two parallel 4-night randomized groups (baseline, two nights of SWS disruption or control, recovery sleep). Setting: Sleep research laboratory. Participants: 44 healthy young (20-30 y), 35 middle-aged (40-55 y), and 31 older (66-83 y) men and women. Interventions: Acoustic stimulation contingent on appearance of slow waves. Measurements and Results: Cognitive performance was assessed before sleep latency tests at five daily time-points. SWS disruption resulted in less positive affect, slower or impaired information processing and sustained attention, less precise motor control, and erroneous implementation, rather than inhibition, of well-practiced actions. These performance impairments had far smaller effect sizes than the increase in daytime sleepiness and differed from baseline to the same extent for each age group. At baseline, younger participants performed better than older participants across many cognitive domains, with largest effects on executive function, response time, sustained attention, and motor control. At baseline, the young were sleepier than other age groups. Conclusions: SWS has been considered a potential mediator of age-related decline in performance, although the effects of SWS disruption on daytime functioning have not been quantified across different cognitive domains nor directly compared to age-related changes in performance. The data imply that two nights of SWS disruption primarily leads to an increase in sleepiness with minor effects on other aspects of daytime functioning, which are different from the substantial effects of age. Citation: Groeger JA, Stanley N, Deacon S, Dijk DJ. Dissociating effects of global sws disruption and healthy aging on waking performance and daytime sleepiness. SLEEP 2014;37(6):1127-1142. PMID:24882908

The Impact of Anxiety-Inducing Distraction on Cognitive Performance: A Combined Brain Imaging and Personality Investigation

PubMed Central

Denkova, Ekaterina; Wong, Gloria; Dolcos, Sanda; Sung, Keen; Wang, Lihong; Coupland, Nicholas; Dolcos, Florin

2010-01-01

Background Previous investigations revealed that the impact of task-irrelevant emotional distraction on ongoing goal-oriented cognitive processing is linked to opposite patterns of activation in emotional and perceptual vs. cognitive control/executive brain regions. However, little is known about the role of individual variations in these responses. The present study investigated the effect of trait anxiety on the neural responses mediating the impact of transient anxiety-inducing task-irrelevant distraction on cognitive performance, and on the neural correlates of coping with such distraction. We investigated whether activity in the brain regions sensitive to emotional distraction would show dissociable patterns of co-variation with measures indexing individual variations in trait anxiety and cognitive performance. Methodology/Principal Findings Event-related fMRI data, recorded while healthy female participants performed a delayed-response working memory (WM) task with distraction, were investigated in conjunction with behavioural measures that assessed individual variations in both trait anxiety and WM performance. Consistent with increased sensitivity to emotional cues in high anxiety, specific perceptual areas (fusiform gyrus - FG) exhibited increased activity that was positively correlated with trait anxiety and negatively correlated with WM performance, whereas specific executive regions (right lateral prefrontal cortex - PFC) exhibited decreased activity that was negatively correlated with trait anxiety. The study also identified a role of the medial and left lateral PFC in coping with distraction, as opposed to reflecting a detrimental impact of emotional distraction. Conclusions These findings provide initial evidence concerning the neural mechanisms sensitive to individual variations in trait anxiety and WM performance, which dissociate the detrimental impact of emotion distraction and the engagement of mechanisms to cope with distracting emotions. Our study sheds light on the neural correlates of emotion-cognition interactions in normal behaviour, which has implications for understanding factors that may influence susceptibility to affective disorders, in general, and to anxiety disorders, in particular. PMID:21152391

Inhibition processes are dissociable and lateralized in human prefrontal cortex.

PubMed

Cipolotti, Lisa; Spanò, Barbara; Healy, Colm; Tudor-Sfetea, Carina; Chan, Edgar; White, Mark; Biondo, Francesca; Duncan, John; Shallice, Tim; Bozzali, Marco

2016-12-01

The prefrontal cortex (PFC) is known to make fundamental contributions to executive functions. However, the precise nature of these contributions is incompletely understood. We focused on a specific executive function, inhibition, the ability to suppress a pre-potent response. Functional imaging and animal studies have studied inhibition. However, there are only few lesion studies, typically reporting discrepant findings. For the first time, we conducted cognitive and neuroimaging investigations on patients with focal unilateral PFC lesions across two widely used inhibitory tasks requiring a verbal response: The Hayling Part 2 and Stroop Colour-Word Tests. We systematically explored the relationship between inhibition, fluid intelligence and lesion location using voxel-based lesion symptom mapping (VLSM). We found that PFC patients were significantly impaired compared with healthy comparison group (HC) on both suppression measures of the Hayling and on the Stroop, even when performance on a fluid intelligence test was covaried. No significant relationship was found between patients' performance on each Hayling suppression measure and the Stroop, once fluid intelligence was partialled out, suggesting that the two tests may involve different kinds of inhibition. After accounting for fluid intelligence, we found a significant interaction between tests, Hayling or Stroop, and site, left or right, of PFC damage. This finding suggesting lateralized functional organization was complemented and extended by our VLSM results. We found that performance on both Hayling suppression measures significantly relied on the integrity of a similar and relatively circumscribed region within the right lateral PFC, in the right lateral superior and middle frontal gyri. In stark contrast, performance on the Stroop relies on the integrity of left lateral superior and middle frontal gyri. Thus, lesion location, right or left PFC, is critical in producing impairments on two inhibitory tasks loading similarly on verbal control. This suggests that the two suppression measures of the Hayling and the Stroop are likely to assess dissociable components of executive functions, related to anatomically defined and lateralized PFC circuits. Our findings also suggest that inhibition may actually comprise qualitatively different forms with different neural substrates. This has clinical implications for the diagnosis and treatment of disinhibition impairments, a common behavioural problem caused by PFC lesions. Our results highlight the need to assess inhibition using a variety of tasks and to develop different types of treatments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Control of concerted two bond versus single bond dissociation in CH(3)Co(CO)(4) via an intermediate state using pump-dump laser pulses.

PubMed

Ambrosek, David; González, Leticia

2007-10-07

Wavepacket propagations on ab initio multiconfigurational two-dimensional potential energy surfaces for CH(3)Co(CO)(4) indicate that after irradiation to the lowest first and second electronic excited states, concerted dissociation of CH(3) and the axial CO ligand takes place. We employ a pump-dump sequence of pulses with appropriate frequencies and time delays to achieve the selective breakage of a single bond by controlling the dissociation angle. The pump and dump pulse sequence exploits the unbound surface where dissociation occurs in a counterintuitive fashion; stretching of one bond in an intermediate state enhances the single dissociation of the other bond.

Executive dysfunction and delay aversion in attention deficit hyperactivity disorder: nosologic and diagnostic implications.

PubMed

Sonuga-Barke, Edmund J S; Sergeant, Joseph A; Nigg, Joel; Willcutt, Erik

2008-04-01

In this article the authors reflect on the role of executive function (EF) deficits and delay aversion (DAv) in the diagnosis of attention deficit hyperactivity disorder (ADHD). The authors, empirical review shows clearly that EF deficits and DAv are implicated in ADHD, although neither is necessary for ADHD nor specific to it. The constructs are somewhat dissociable from one another so that each may represent a distinctive feature associated with an ADHD subsample. The authors argue that neither EF deficits nor DAv add much value to the diagnosis of ADHD as it is currently conceptualized, but may be crucial in helping to partition heterogeneity in the condition, leading to the refinement of ADHD nosology.

Differential patterns of functional and structural plasticity within and between inferior frontal gyri support training-induced improvements in inhibitory control proficiency.

PubMed

Chavan, Camille F; Mouthon, Michael; Draganski, Bogdan; van der Zwaag, Wietske; Spierer, Lucas

2015-07-01

Ample evidence indicates that inhibitory control (IC), a key executive component referring to the ability to suppress cognitive or motor processes, relies on a right-lateralized fronto-basal brain network. However, whether and how IC can be improved with training and the underlying neuroplastic mechanisms remains largely unresolved. We used functional and structural magnetic resonance imaging to measure the effects of 2 weeks of training with a Go/NoGo task specifically designed to improve frontal top-down IC mechanisms. The training-induced behavioral improvements were accompanied by a decrease in neural activity to inhibition trials within the right pars opercularis and triangularis, and in the left pars orbitalis of the inferior frontal gyri. Analyses of changes in brain anatomy induced by the IC training revealed increases in grey matter volume in the right pars orbitalis and modulations of white matter microstructure in the right pars triangularis. The task-specificity of the effects of training was confirmed by an absence of change in neural activity to a control working memory task. Our combined anatomical and functional findings indicate that differential patterns of functional and structural plasticity between and within inferior frontal gyri enhanced the speed of top-down inhibition processes and in turn IC proficiency. The results suggest that training-based interventions might help overcoming the anatomic and functional deficits of inferior frontal gyri manifesting in inhibition-related clinical conditions. More generally, we demonstrate how multimodal neuroimaging investigations of training-induced neuroplasticity enable revealing novel anatomo-functional dissociations within frontal executive brain networks. © 2015 Wiley Periodicals, Inc.

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.

In-Vacuum Dissociator for Atomic-Hydrogen Masers

NASA Technical Reports Server (NTRS)

Vessot, R. F.

1987-01-01

Thermal control and vacuum sealing achieved while contamination avoided. Simple, relatively inexpensive molecular-hydrogen dissociator for atomic-hydrogen masers used on Earth or in vacuum of space. No air cooling required, and absence of elastomeric O-ring seals prevents contamination. In-vacuum dissociator for atomic hydrogen masers, hydrogen gas in glass dissociator dissociated by radio-frequency signal transmitted from surrounding 3-turn coil. Heat in glass conducted away by contacting metal surfaces.

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.

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.

Evaluation of the evidence for the trauma and fantasy models of dissociation.

PubMed

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

2012-05-01

The relationship between a reported history of trauma and dissociative symptoms has been explained in 2 conflicting ways. Pathological dissociation has been conceptualized as a response to antecedent traumatic stress and/or severe psychological adversity. Others have proposed that dissociation makes individuals prone to fantasy, thereby engendering confabulated memories of trauma. We examine data related to a series of 8 contrasting predictions based on the trauma model and the fantasy model of dissociation. In keeping with the trauma model, the relationship between trauma and dissociation was consistent and moderate in strength, and remained significant when objective measures of trauma were used. Dissociation was temporally related to trauma and trauma treatment, and was predictive of trauma history when fantasy proneness was controlled. Dissociation was not reliably associated with suggestibility, nor was there evidence for the fantasy model prediction of greater inaccuracy of recovered memory. Instead, dissociation was positively related to a history of trauma memory recovery and negatively related to the more general measures of narrative cohesion. Research also supports the trauma theory of dissociation as a regulatory response to fear or other extreme emotion with measurable biological correlates. We conclude, on the basis of evidence related to these 8 predictions, that there is strong empirical support for the hypothesis that trauma causes dissociation, and that dissociation remains related to trauma history when fantasy proneness is controlled. We find little support for the hypothesis that the dissociation-trauma relationship is due to fantasy proneness or confabulated memories of trauma. 2012 APA, all rights reserved

Theory of mind and executive function during middle childhood across cultures.

PubMed

Wang, Zhenlin; Devine, Rory T; Wong, Keri K; Hughes, Claire

2016-09-01

Previous studies with preschoolers have reported "East-West" contrasts in children's executive function (East>West) and theory of mind (East

Remote control of the dissociative ionization of H2 based on electron-H2 + entanglement

NASA Astrophysics Data System (ADS)

Wang, Jun-Ping; He, Feng

2018-04-01

The single ionization of H2 in strong laser fields creates the correlated electron-H2 + pair. Based on such a correlation, we conceive a strategy to control the energy spectra of the freed electron or dissociative fragments by simulating the time-dependent Schrödinger equation. Two attosecond pulses in a train produce the replica of electron-H2 + pairs, which are to be steered by a time-delayed phase-stabilized (mid)infrared laser pulse. By controlling the behavior of the freed electron, the dissociation of H2 + can be controlled even though there is no direct laser-H2 + coupling. On the other hand, the photoelectron energy spectra can be manipulated via laser-H2 + coupling. This study demonstrates the entanglement of molecular quantum wave packets, and affords a route to remotely control molecular dissociative ionization.

Recognition of facial and musical emotions in Parkinson's disease.

PubMed

Saenz, A; Doé de Maindreville, A; Henry, A; de Labbey, S; Bakchine, S; Ehrlé, N

2013-03-01

Patients with amygdala lesions were found to be impaired in recognizing the fear emotion both from face and from music. In patients with Parkinson's disease (PD), impairment in recognition of emotions from facial expressions was reported for disgust, fear, sadness and anger, but no studies had yet investigated this population for the recognition of emotions from both face and music. The ability to recognize basic universal emotions (fear, happiness and sadness) from both face and music was investigated in 24 medicated patients with PD and 24 healthy controls. The patient group was tested for language (verbal fluency tasks), memory (digit and spatial span), executive functions (Similarities and Picture Completion subtests of the WAIS III, Brixton and Stroop tests), visual attention (Bells test), and fulfilled self-assessment tests for anxiety and depression. Results showed that the PD group was significantly impaired for recognition of both fear and sadness emotions from facial expressions, whereas their performance in recognition of emotions from musical excerpts was not different from that of the control group. The scores of fear and sadness recognition from faces were neither correlated to scores in tests for executive and cognitive functions, nor to scores in self-assessment scales. We attributed the observed dissociation to the modality (visual vs. auditory) of presentation and to the ecological value of the musical stimuli that we used. We discuss the relevance of our findings for the care of patients with PD. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

Deficits in inhibitory control and conflict resolution on cognitive and motor tasks in Parkinson's disease.

PubMed

Obeso, Ignacio; Wilkinson, Leonora; Casabona, Enrique; Bringas, Maria Luisa; Álvarez, Mario; Álvarez, Lázaro; Pavón, Nancy; Rodríguez-Oroz, Maria-Cruz; Macías, Raúl; Obeso, Jose A; Jahanshahi, Marjan

2011-07-01

Recent imaging studies in healthy controls with a conditional stop signal reaction time (RT) task have implicated the subthalamic nucleus (STN) in response inhibition and the pre-supplementary motor area (pre-SMA) in conflict resolution. Parkinson's disease (PD) is characterized by striatal dopamine deficiency and overactivity of the STN and underactivation of the pre-SMA during movement. We used the conditional stop signal RT task to investigate whether PD produced similar or dissociable effects on response initiation, response inhibition and response initiation under conflict. In addition, we also examined inhibition of prepotent responses on three cognitive tasks: the Stroop, random number generation and Hayling sentence completion. PD patients were impaired on the conditional stop signal reaction time task, with response initiation both in situations with or without conflict and response inhibition all being significantly delayed, and had significantly greater difficulty in suppressing prepotent or habitual responses on the Stroop, Hayling and random number generation tasks relative to controls. These results demonstrate the existence of a generalized inhibitory deficit in PD, which suggest that PD is a disorder of inhibition as well as activation and that in situations of conflict, executive control over responses is compromised.

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.

Inhibition, Executive Function, and Freezing of Gait

PubMed Central

Cohen, Rajal G.; Klein, Krystal A.; Nomura, Mariko; Fleming, Michael; Mancini, Martina; Giladi, Nir; Nutt, John G.; Horak, Fay B.

2014-01-01

Background Studies suggest that freezing of gait (FoG) in people with Parkinson’s disease (PD) is associated with declines in executive function (EF). However, EF is multi-faceted, including three dissociable components: inhibiting prepotent responses, switching between task sets, and updating working memory. Objective This study investigated which aspect of EF is most strongly associated with FoG in PD. Method Three groups were studied: adults with PD (with and without FoG) and age-matched, healthy adults. All participants completed a battery of cognitive tasks previously shown to discriminate among the three EF components. Participants also completed a turning-in-place task that was scored for FoG by neurologists blind to subjects’ self-reported FoG. Results Compared to both other groups, participants with FoG showed significant performance deficits in tasks associated with inhibitory control, even after accounting for differences in disease severity, but no significant deficits in task-switching or updating working memory. Surprisingly, the strongest effect was an intermittent tendency of participants with FoG to hesitate, and thus miss the response window, on go trials in the Go-Nogo task. The FoG group also made slower responses in the conflict condition of the Stroop task. Physician-rated FoG scores were correlated both with failures to respond on go trials and with failures to inhibit responses on nogo trials in the Go-Nogo task. Conclusion These results suggest that FoG is associated with a specific inability to appropriately engage and release inhibition, rather than with a general executive deficit. PMID:24496099

[Language and executive functioning skills of students with attention deficit/hyperactivity disorder (ADHD), and in reading comprehension difficulties (RCD)].

PubMed

Miranda Casas, Ana; Fernández Andrés, María Inmaculada; García Castellar, Rosa; Roselló Miranda, Belén; Colomer Diago, Carla

2011-11-01

The aim of this work was to study the specificity of deficits in linguistic and executive functioning of students with ADHD and with RCD and to determine the profile of deficits in the comorbid group (ADHD+RCD). Participants in the study were 84 students, ages 12-16 years divided into four groups with an equal number of subjects (N= 21): ADHD, RCD, ADHD+RCD and comparison group (without ADHD and without RCD). We measured vocabulary, oral comprehension, lexical access, verbal and visual working memory, inhibition and attention. The results show that the ADHD+RCD group presents the most important linguistic deficits, followed by the RCD group. On the other hand, the three clinical groups (ADHD, RCD and ADHD+RCD) display greater performance problems in working memory than the comparison group, whereas the two groups with ADHD had more problems in attention and inhibition. These results suggest the dissociation of linguistic and executive deficits that affect the RCD group and ADHD group to a greater extent, respectively. Lastly, the comorbid group showed deficits both in language and in executive skills. We discuss the implications of these findings for designing interventions.

Control of electron excitation and localization in the dissociation of H2(+) and its isotopes using two sequential ultrashort laser pulses.

PubMed

He, Feng; Ruiz, Camilo; Becker, Andreas

2007-08-24

We study the control of dissociation of the hydrogen molecular ion and its isotopes exposed to two ultrashort laser pulses by solving the time-dependent Schrödinger equation. While the first ultraviolet pulse is used to excite the electron wave packet on the dissociative 2psigma{u} state, a second time-delayed near-infrared pulse steers the electron between the nuclei. Our results show that by adjusting the time delay between the pulses and the carrier-envelope phase of the near-infrared pulse, a high degree of control over the electron localization on one of the dissociating nuclei can be achieved (in about 85% of all fragmentation events). The results demonstrate that current (sub-)femtosecond technology can provide a control over both electron excitation and localization in the fragmentation of molecules.

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.

Imaging and control of interfering wave packets in a dissociating molecule.

PubMed

Skovsen, Esben; Machholm, Mette; Ejdrup, Tine; Thøgersen, Jan; Stapelfeldt, Henrik

2002-09-23

Using two identical 110 femtosecond (fs) optical pulses separated by 310 fs, we launch two dissociative wave packets in I2. We measure the square of the wave function as a function of both the internuclear separation, /Psi(R)/(2), and of the internuclear velocity, /Psi(v(R))/(2), by ionizing the dissociating molecule with an intense 20 fs probe pulse. Strong interference is observed in both /Psi(R)/(2) and in /Psi(v(R))/(2). The interference, and therefore the shape of the wave function, is controlled through the phase difference between the two dissociation pulses in good agreement with calculations.

Income, neural executive processes, and preschool children's executive control.

PubMed

Ruberry, Erika J; Lengua, Liliana J; Crocker, Leanna Harris; Bruce, Jacqueline; Upshaw, Michaela B; Sommerville, Jessica A

2017-02-01

This study aimed to specify the neural mechanisms underlying the link between low household income and diminished executive control in the preschool period. Specifically, we examined whether individual differences in the neural processes associated with executive attention and inhibitory control accounted for income differences observed in performance on a neuropsychological battery of executive control tasks. The study utilized a sample of preschool-aged children (N = 118) whose families represented the full range of income, with 32% of families at/near poverty, 32% lower income, and 36% middle to upper income. Children completed a neuropsychological battery of executive control tasks and then completed two computerized executive control tasks while EEG data were collected. We predicted that differences in the event-related potential (ERP) correlates of executive attention and inhibitory control would account for income differences observed on the executive control battery. Income and ERP measures were related to performance on the executive control battery. However, income was unrelated to ERP measures. The findings suggest that income differences observed in executive control during the preschool period might relate to processes other than executive attention and inhibitory control.

Autophagy promotes caspase-dependent cell death during Drosophila development.

PubMed

Mohseni, Nilufar; McMillan, Stephanie C; Chaudhary, Roopali; Mok, Jane; Reed, Bruce H

2009-04-01

The relationship between autophagic cell death and apoptosis is a poorly understood aspect of programmed cell death (PCD). We have examined this relationship by studying the elimination of an extra-embryonic tissue, known as the amnioserosa (AS), during Drosophila development. The AS becomes autophagic during the final stages of embryogenesis; ultimately, however, the elimination of the AS involves caspase-dependent nuclear fragmentation, tissue dissociation and engulfment by phagocytic macrophages. Mutants that are defective in the activation or execution of caspase-dependent PCD fail to degrade and eliminate the AS but show no abatement in AS autophagy. Sustained autophagy does not, therefore, necessarily result in cell death. Surprisingly, the downregulation of autophagy also results in a persistent AS phenotype and reduced cell death. Conversely, upregulation of autophagy results in caspase-dependent premature AS dissociation. These observations are consistent with the interpretation that autophagy is a prerequisite for caspase-dependent cell death in the AS.

Dissociating motivational direction and affective valence: specific emotions alter central motor processes.

PubMed

Coombes, Stephen A; Cauraugh, James H; Janelle, Christopher M

2007-11-01

We aimed to clarify the relation between affective valence and motivational direction by specifying how central and peripheral components of extension movements are altered according to specific unpleasant affective states. As predicted, premotor reaction time was quicker for extension movements initiated during exposure to attack than for extension movements initiated during exposure to all other valence categories (mutilation, erotic couples, opposite-sex nudes, neutral humans, household objects, blank). Exposure to erotic couples and mutilations yielded greater peak force than exposure to images of attack, neutral humans, and household objects. Finally, motor reaction time and peak electromyographic amplitude were not altered by valence. These findings indicate that unpleasant states do not unilaterally prime withdrawal movements, and that the quick execution of extension movements during exposure to threatening images is due to rapid premotor, rather than motor, reaction time. Collectively, our findings support the call for dissociating motivational direction and affective valence.

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 complexity: Antecedents and clinical correlates of a new construct.

PubMed

Briere, John; Dietrich, Anne; Semple, Randye J

2016-09-01

To the extent that dissociation is a multidimensional phenomenon, and given a growing literature on complex posttraumatic outcomes, we hypothesized a new construct: dissociative complexity (DC). DC is defined as the tendency to simultaneously endorse multiple, relatively independent dissociative dimensions into their clinical ranges, and therefore represents the overall breadth or complexity of an individual's dissociative response. DC was evaluated in general population and prison participants using the Multiscale Dissociation Inventory (MDI; Briere, 2002). DC was higher among prisoners and women, and, as hypothesized, was associated with cumulative trauma and serious comorbidities (suicidality and substance abuse), even when controlling for generally elevated dissociation. DC appears to be a meaningful clinical construct that is phenomenologically and empirically different from a unidimensional index of dissociative severity. DC may serve as a clinical marker for multiple trauma exposures, complex dissociative outcomes, and risk of problematic comorbidities. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Clinical characteristics and brain PET findings in 3 cases of dissociative amnesia: disproportionate retrograde deficit and posterior middle temporal gyrus hypometabolism.

PubMed

Thomas-Antérion, C; Dubas, F; Decousus, M; Jeanguillaume, C; Guedj, E

2014-10-01

Precipitated by psychological stress, dissociative amnesia occurs in the absence of identifiable brain damage. Its clinical characteristics and functional neural basis are still a matter of controversy. In the present paper, we report 3 cases of retrograde autobiographical amnesia, characterized by an acute onset concomitant with emotional/neurological precipitants. We present 2 cases of dissociative amnesia with fugue (cases 1 and 2), and one case of focal dissociative amnesia after a minor head trauma (case 3). The individual case histories and neuropsychological characteristics are reported, as well as the whole-brain voxel-based 18FDG-PET metabolic findings obtained at group-level in comparison to 15 healthy subjects. All patients suffered from autobiographical memory loss, in the absence of structural lesion. They had no significant impairment of anterograde memory or of executive function. Impairment of autobiographical memory was complete for two of the three patients, with loss of personal identity (cases 1 and 2). A clinical recovery was found for the two patients in whom follow-up was available (cases 2 and 3). Voxel-based group analysis highlighted a metabolic impairment of the right posterior middle temporal gyrus. 18FDG-PET was repeated in case 3, and showed a complete functional brain recovery. The situation of dissociative amnesia with disproportionate retrograde amnesia is clinically heterogeneous between individuals. Our findings may suggest that impairment of high-level integration of visual and/or emotional information processing involving dysfunction of the right posterior middle temporal gyrus could reduce triggering of multi-modal visual memory traces, thus impeding reactivation of aversive memories. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Imbalance between cognitive systems in alcohol-dependence and Korsakoff syndrome: An exploration using the Alcohol Flanker Task.

PubMed

Brion, Mélanie; Dormal, Valérie; Lannoy, Séverine; Mertens, Serge; de Timary, Philippe; Maurage, Pierre

2018-03-06

Alcohol-dependent individuals (ALC) simultaneously present decreased inhibitory control and increased attention towards alcohol-related cues. The dual-process models have proposed that these symptoms reflect an imbalance between prefrontal/reflective and limbic/automatic systems, respectively leading to cognitive dysfunctions in executive processes and to alcohol-related bias. However, most previous research has focused on a separate exploration of these systems among ALC, and the direct measure of their interactions remains to be conducted. Moreover, no study has explored the evolution of this imbalance across the successive stages of alcohol-related disorders, and particularly in Korsakoff syndrome (KS), the most frequent neurological complication of alcohol-dependence. Ten KS, 14 ALC, and 14 matched control participants performed a modified Flanker task, the "Alcohol Flanker Task," based on congruent, incongruent, and neutral conditions with alcohol-related stimuli. This task required inhibitory processing on alcohol-related stimuli and evaluated, through a behavioral approach, the interaction between reflective and automatic systems, as well as its evolution between ALC and KS. ALC and KS both presented high reactivity towards alcohol-related stimuli, confirming the presence of alcohol-related bias. KS showed increased omission rates (related to distractor interference) while ALC showed higher false-alarm rates (related to prepotent response inhibition). These results suggest that different inhibitory subcomponents might be altered at the successive stages of the pathology, and experimentally confirms the crucial role of the interaction between reflective and automatic processes in alcohol-use disorders. The present results reinforce the proposal that alcohol-related cues significantly impact inhibitory control in alcohol-related disorders. However, ALC and KS present different patterns of deficits depending on task complexity (i.e., executive load), thus suggesting a dissociation in inhibitory functions when processing alcohol-related cues.

Testing the diagnosis of dissociative identity disorder through measures of dissociation, absorption, hypnotizability and PTSD: a Norwegian pilot study.

PubMed

Dale, Karl Yngvar; Berg, Renate; Elden, Ake; Ødegård, Atle; Holte, Arne

2009-01-01

A total of 14 women meeting criteria for dissociative identity disorder (DID) based on the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]) were compared to a group of women (n = 10) with other dissociative diagnoses and a group of normal controls (n = 14) with regard to dissociativity, absorption, trauma related symptoms and hypnotizability. Both of the clinical groups reported histories of childhood trauma and attained high PTSD scores. The DID group differed significantly from the group with other dissociative diagnoses and the non-diagnosed comparison group with regard to hypnotizability, the variety of dissociative symptomatology, and the magnitude of dissociative symptomatology. However, no significant differences between the two clinical groups were detected with regard to absorption, general dissociative level, or symptoms related to traumatic stress. Results support the notion that DID can be regarded as a clinical entity which is separable from other dissociative disorders. Results also indicated that hypnotizability is the most important clinical feature of DID.

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

Working memory and executive functions in transient global amnesia.

PubMed

Quinette, Peggy; Guillery, Bérengère; Desgranges, Béatrice; de la Sayette, Vincent; Viader, Fausto; Eustache, Francis

2003-09-01

Transient global amnesia (TGA) is usually considered to produce a profound impairment of long-term episodic memory, while at the same time sparing working memory. However, this neuropsychological dissociation has rarely been examined in detail. While a few studies have assessed some components of working memory in TGA, the results that have been obtained are far from conclusive. To clarify this issue, we carried out a comprehensive investigation of working memory in 10 patients during a TGA attack. In the first study, we report the results from three patients examined with a battery of neuropsychological tests designed to assess each of the three subcomponents of Baddeley's model of working memory. In a second study, seven different patients underwent neuropsychological investigations that focused specifically on the central executive system, using a protocol derived from a study by Miyake and colleagues. Our findings showed that subcomponents of working memory, such as the phonological loop and visuo-spatial sketch pad, were spared in TGA patients. Specific executive functions that entailed inhibitory control, dual task performance, updating and shifting mechanisms were also found to be normal. However, we found significantly impaired performance for the Brown-Peterson test, and that TGA patients were significantly impaired in the recollection of their episodic memories. They also made reduced numbers of 'remember' compared with 'know' judgments in the episodic memory test several days after TGA. On the basis of our findings, it would appear that the episodic memory deficit during TGA is not related to elementary aspects of executive functioning. Our data also highlight the nature of the cognitive mechanisms involved in the Brown-Peterson task, which may well depend on long-term memory (such as the process of semantic encoding). Lastly, the selective deficit in recollective episodic memories observed in TGA may be principally related to medial temporal lobe abnormalities that have been reported in this syndrome.

Vortioxetine reduces BOLD signal during performance of the N-back working memory task: a randomised neuroimaging trial in remitted depressed patients and healthy controls.

PubMed

Smith, J; Browning, M; Conen, S; Smallman, R; Buchbjerg, J; Larsen, K G; Olsen, C K; Christensen, S R; Dawson, G R; Deakin, J F; Hawkins, P; Morris, R; Goodwin, G; Harmer, C J

2018-05-01

Cognitive dysfunction is common in depression during both acute episodes and remission. Vortioxetine is a novel multimodal antidepressant that has improved cognitive function including executive function in depressed patients in randomised placebo-controlled clinical trials. However, it is unclear whether vortioxetine is able to target directly the neural circuitry implicated in the cognitive deficits in depression. Remitted depressed (n=48) and healthy volunteers (n=48) were randomised to receive 14 days treatment with 20 mg vortioxetine or placebo in a double-blind design. The effects of treatment on functional magnetic resonance imaging responses during an N-back working memory task were assessed at baseline and at the end of treatment. Neuropsychological measures of executive function, speed and information processing, attention and learning and memory were examined with the Trail Making Test (TMT), Rey Auditory Learning Test and Digit Symbol Substitution Test before and after treatment; subjective cognitive function was assessed using the Perceived Deficits Questionnaire (PDQ). Compared with placebo, vortioxetine reduced activation in the right dorsolateral prefrontal cortex and left hippocampus during the N-back task compared with placebo. Vortioxetine also increased TMT-A performance and self-reported cognitive function on the PDQ. These effects were seen across both subject groups. Vortioxetine modulates neural responses across a circuit subserving working memory in a direction opposite to the changes described in depression, when performance is maintained. This study provides evidence that vortioxetine has direct effects on the neural circuitry supporting cognitive function that can be dissociated from its effects on the mood symptoms of depression.

[Childhood traumatization, dissociation and nonsuicidal self-injurious behavior in borderline personality disorder].

PubMed

Merza, Katalin; Harmatta, János; Papp, Gábor; Kuritárné Szabó, Ildikó

2017-05-01

Childhood traumatization plays a significant role in the etiology of borderline personality disorder. Studies found a significant association between childhood traumatization, dissociation, and nonsuicidal self-injurious behavior. The aim of our study was to assess dissociation and nonsuicidal self-injury among borderline inpatients and to reveal the association between childhood traumatization, dissociation, and self-injurious behavior. The sample consisted of 80 borderline inpatients and 73 depressed control patients. Childhood traumatization, dissociation and self-injurious behavior were assessed by questionnaires. Borderline patients reported severe and multiplex childhood traumatization. Cumulative trauma score and sexual abuse were the strongest predictors of dissociation. Furthermore, we have found that cumulative trauma score and dissociation were highly predictive of self-injurious behavior. Our results suggest that self-injurious behavior and dissociation in borderline patients can be regarded as indicators of childhood traumatization. Orv Hetil. 2017; 158(19): 740-747.

Inter-Identity Autobiographical Amnesia in Patients with Dissociative Identity Disorder

PubMed Central

Huntjens, Rafaële J. C.; Verschuere, Bruno; McNally, Richard J.

2012-01-01

Background A major symptom of Dissociative Identity Disorder (DID; formerly Multiple Personality Disorder) is dissociative amnesia, the inability to recall important personal information. Only two case studies have directly addressed autobiographical memory in DID. Both provided evidence suggestive of dissociative amnesia. The aim of the current study was to objectively assess transfer of autobiographical information between identities in a larger sample of DID patients. Methods Using a concealed information task, we assessed recognition of autobiographical details in an amnesic identity. Eleven DID patients, 27 normal controls, and 23 controls simulating DID participated. Controls and simulators were matched to patients on age, education level, and type of autobiographical memory tested. Findings Although patients subjectively reported amnesia for the autobiographical details included in the task, the results indicated transfer of information between identities. Conclusion The results call for a revision of the DID definition. The amnesia criterion should be modified to emphasize its subjective nature. PMID:22815769

Inter-identity autobiographical amnesia in patients with dissociative identity disorder.

PubMed

Huntjens, Rafaële J C; Verschuere, Bruno; McNally, Richard J

2012-01-01

A major symptom of Dissociative Identity Disorder (DID; formerly Multiple Personality Disorder) is dissociative amnesia, the inability to recall important personal information. Only two case studies have directly addressed autobiographical memory in DID. Both provided evidence suggestive of dissociative amnesia. The aim of the current study was to objectively assess transfer of autobiographical information between identities in a larger sample of DID patients. Using a concealed information task, we assessed recognition of autobiographical details in an amnesic identity. Eleven DID patients, 27 normal controls, and 23 controls simulating DID participated. Controls and simulators were matched to patients on age, education level, and type of autobiographical memory tested. Although patients subjectively reported amnesia for the autobiographical details included in the task, the results indicated transfer of information between identities. The results call for a revision of the DID definition. The amnesia criterion should be modified to emphasize its subjective nature.

Control of photodissociation and photoionization of the NaI molecule by dynamic Stark effect.

PubMed

Han, Yong-Chang; Yuan, Kai-Jun; Hu, Wen-Hui; Cong, Shu-Lin

2009-01-28

The diabatic photodissociation and photoionization processes of the NaI molecule are studied theoretically using the quantum wave packet method. A pump laser pulse is used to prepare a dissociation wave packet that propagates through both the ionic channel (NaI-->Na(+)+I(-)) and the covalent channel (NaI-->Na+I). A Stark pulse is used to control the diabatic dissociation dynamics and a probe pulse is employed to ionize the products from the two channels. Based on the first order nonresonant nonperturbative dynamic Stark effect, the dissociation probabilities and the branching ratio of the products from the two channels can be controlled. Moreover the final photoelectron kinetic energy distribution can also be affected by the Stark pulse. The influences of the delay time, intensity, frequency, and carrier-envelope phase of the Stark pulse on the dissociation and ionization dynamics of the NaI molecule are discussed in detail.

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.

Hypnotizability and Dissociativity in Sexually Abused Girls.

ERIC Educational Resources Information Center

Putnam, Frank W.; And Others

1995-01-01

This study assessed the relationships among hypnotizability, clinical dissociation and traumatic antecedents in 54 sexually abused girls, ages 6 to 15 years, and 51 matched controls. There were no significant differences in hypnotizability between abuse and control subjects. However, in the abuse group, highly hypnotizable subjects were…

Parallel Alterations of Functional Connectivity during Execution and Imagination after Motor Imagery Learning

PubMed Central

Zhang, Rushao; Hui, Mingqi; Long, Zhiying; Zhao, Xiaojie; Yao, Li

2012-01-01

Background Neural substrates underlying motor learning have been widely investigated with neuroimaging technologies. Investigations have illustrated the critical regions of motor learning and further revealed parallel alterations of functional activation during imagination and execution after learning. However, little is known about the functional connectivity associated with motor learning, especially motor imagery learning, although benefits from functional connectivity analysis attract more attention to the related explorations. We explored whether motor imagery (MI) and motor execution (ME) shared parallel alterations of functional connectivity after MI learning. Methodology/Principal Findings Graph theory analysis, which is widely used in functional connectivity exploration, was performed on the functional magnetic resonance imaging (fMRI) data of MI and ME tasks before and after 14 days of consecutive MI learning. The control group had no learning. Two measures, connectivity degree and interregional connectivity, were calculated and further assessed at a statistical level. Two interesting results were obtained: (1) The connectivity degree of the right posterior parietal lobe decreased in both MI and ME tasks after MI learning in the experimental group; (2) The parallel alterations of interregional connectivity related to the right posterior parietal lobe occurred in the supplementary motor area for both tasks. Conclusions/Significance These computational results may provide the following insights: (1) The establishment of motor schema through MI learning may induce the significant decrease of connectivity degree in the posterior parietal lobe; (2) The decreased interregional connectivity between the supplementary motor area and the right posterior parietal lobe in post-test implicates the dissociation between motor learning and task performing. These findings and explanations further revealed the neural substrates underpinning MI learning and supported that the potential value of MI learning in motor function rehabilitation and motor skill learning deserves more attention and further investigation. PMID:22629308

Normal Aging and the Dissociable Prototype Learning Systems

PubMed Central

Glass, Brian D.; Chotibut, Tanya; Pacheco, Jennifer; Schnyer, David M.; Maddox, W. Todd

2011-01-01

Dissociable prototype learning systems have been demonstrated behaviorally and with neuroimaging in younger adults as well as with patient populations. In A/not-A (AN) prototype learning, participants are shown members of category A during training, and during test are asked to decide whether novel items are in category A or are not in category A. Research suggests that AN learning is mediated by a perceptual learning system. In A/B (AB) prototype learning, participants are shown members of category A and B during training, and during test are asked to decide whether novel items are in category A or category B. In contrast to AN, research suggests that AB learning is mediated by a declarative memory system. The current study examined the effects of normal aging on AN and AB prototype learning. We observed an age-related deficit in AB learning, but an age-related advantage in AN learning. Computational modeling supports one possible interpretation based on narrower selective attentional focus in older adults in the AB task and broader selective attention in the AN task. Neuropsychological testing in older participants suggested that executive functioning and attentional control were associated with better performance in both tasks. However, nonverbal memory was associated with better AN performance, while visual attention was associated with worse AB performance. The results support an interactive memory systems approach and suggest that age-related declines in one memory system can lead to deficits in some tasks, but to enhanced performance in others. PMID:21875215

Conceptual Model-Based Systems Biology: Mapping Knowledge and Discovering Gaps in the mRNA Transcription Cycle

PubMed Central

Somekh, Judith; Choder, Mordechai; Dori, Dov

2012-01-01

We propose a Conceptual Model-based Systems Biology framework for qualitative modeling, executing, and eliciting knowledge gaps in molecular biology systems. The framework is an adaptation of Object-Process Methodology (OPM), a graphical and textual executable modeling language. OPM enables concurrent representation of the system's structure—the objects that comprise the system, and behavior—how processes transform objects over time. Applying a top-down approach of recursively zooming into processes, we model a case in point—the mRNA transcription cycle. Starting with this high level cell function, we model increasingly detailed processes along with participating objects. Our modeling approach is capable of modeling molecular processes such as complex formation, localization and trafficking, molecular binding, enzymatic stimulation, and environmental intervention. At the lowest level, similar to the Gene Ontology, all biological processes boil down to three basic molecular functions: catalysis, binding/dissociation, and transporting. During modeling and execution of the mRNA transcription model, we discovered knowledge gaps, which we present and classify into various types. We also show how model execution enhances a coherent model construction. Identification and pinpointing knowledge gaps is an important feature of the framework, as it suggests where research should focus and whether conjectures about uncertain mechanisms fit into the already verified model. PMID:23308089

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.

Domain-Specific Control Mechanisms for Emotional and Nonemotional Conflict Processing

ERIC Educational Resources Information Center

Soutschek, Alexander; Schubert, Torsten

2013-01-01

Recent neuroimaging studies suggest that the human brain activates dissociable cognitive control networks in response to conflicts arising within the cognitive and the affective domain. The present study tested the hypothesis that nonemotional and emotional conflict regulation can also be dissociated on a functional level. For that purpose, we…

A case of dissociative fugue and general amnesia with an 11-year follow-up.

PubMed

Helmes, Edward; Brown, Julie-May; Elliott, Linda

2015-01-01

Dissociative fugue refers to loss of personal identity, often with the associated loss of memories of events (general amnesia). Here we report on the psychological assessment of a 54-year-old woman with loss of identity and memories of 33 years of her life attributed to dissociative fugue, along with a follow-up 11 years later. Significant levels of personal injury and stress preceded the onset of the amnesia. A detailed neuropsychological assessment was completed at a university psychology clinic, with a follow-up assessment there about 11 years later with an intent to determine whether changes in her cognitive status were associated with better recall of her life and with her emotional state. Psychomotor slowing and low scores on measures of attention and both verbal and visual memory were present initially, along with significant psychological distress associated with the diagnosis of posttraumatic stress disorder. Although memories of her life had not returned by follow-up, distress had abated and memory test scores had improved. The passage of time and a better emotional state did not lead to recovery of lost memories. Contrary to expectations, performance on tests of executive functions was good on both occasions. Multiple stressful events are attributed as having a role in maintaining the loss of memories.

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.

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.

Information processing of an acquaintance rape scenario among high- and low-dissociating college women.

PubMed

Sandberg, D A; Lynn, S J; Matorin, A I

2001-07-01

To assess the impact of dissociation on information processing, 66 college women with high and low levels of trait dissociation were studied with regard to how they unitized videotape segments of an acquaintance rape scenario (actual assault not shown) and a nonthreatening control scenario. Unitization is a paradigm that measures how actively people process stimuli by recording how many times they press a button to indicate that they have seen a significant or meaningful event. Trait dissociation was negatively correlated with participants' unitization of the acquaintance rape videotape, unitization was positively correlated with danger cue identification, and state dissociation was negatively correlated with dangerousness ratings.

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.

Simple dissociations for a higher-powered neuropsychology.

PubMed

McIntosh, Robert D

2018-06-01

Dissociations in cognitive neuropsychology are often investigated at the level of the single-case, and formal criteria exist for the detection of dissociations, and their sub-classification into 'classical' and 'strong' types. These criteria require a patient to show a frank deficit on one task (for a classical dissociation) or both tasks (for a strong dissociation), and a significantly extreme difference between tasks. I propose that only the significant between-task difference is logically necessary, and that if this simple criterion is met, the patient should be said to show a dissociation. Using Monte Carlo simulations, I show that this simplification increases the power to detect dissociations across a range of practically-relevant conditions, whilst retaining excellent control over Type I error. Additional testing for frank deficits on each task provides further qualifying information, but using these test outcomes to categorise dissociations as classical or strong may be too uncertain to guide theoretical inferences reliably. I suggest that we might instead characterise the strength of the dissociation using a continuous index, such as the effect size of the between-task difference. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ordinal Process Dissociation and the Measurement of Automatic and Controlled Processes

ERIC Educational Resources Information Center

Hirshman, Elliot

2004-01-01

The process-dissociation equations (L. Jacoby, 1991) have been applied to results from inclusion and exclusion tasks to derive quantitative estimates of the influence of controlled and automatic processes on memory. This research has provoked controversies (e.g., T. Curran & D. Hintzman, 1995) regarding the validity of specific assumptions…

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.

Egocentric virtual maze learning in adult survivors of childhood abuse with dissociative disorders: evidence from functional magnetic resonance imaging.

PubMed

Weniger, Godehard; Siemerkus, Jakob; Barke, Antonia; Lange, Claudia; Ruhleder, Mirjana; Sachsse, Ulrich; Schmidt-Samoa, Carsten; Dechent, Peter; Irle, Eva

2013-05-30

Present neuroimaging findings suggest two subtypes of trauma response, one characterized predominantly by hyperarousal and intrusions, and the other primarily by dissociative symptoms. The neural underpinnings of these two subtypes need to be better defined. Fourteen women with childhood abuse and the current diagnosis of dissociative amnesia or dissociative identity disorder but without posttraumatic stress disorder (PTSD) and 14 matched healthy comparison subjects underwent functional magnetic resonance imaging (fMRI) while finding their way in a virtual maze. The virtual maze presented a first-person view (egocentric), lacked any topographical landmarks and could be learned only by using egocentric navigation strategies. Participants with dissociative disorders (DD) were not impaired in learning the virtual maze when compared with controls, and showed a similar, although weaker, pattern of activity changes during egocentric learning when compared with controls. Stronger dissociative disorder severity of participants with DD was related to better virtual maze performance, and to stronger activity increase within the cingulate gyrus and the precuneus. Our results add to the present knowledge of preserved attentional and visuospatial mnemonic functioning in individuals with DD. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Global similarity predicts dissociation of classification and recognition: evidence questioning the implicit-explicit learning distinction in amnesia.

PubMed

Jamieson, Randall K; Holmes, Signy; Mewhort, D J K

2010-11-01

Dissociation of classification and recognition in amnesia is widely taken to imply 2 functional systems: an implicit procedural-learning system that is spared in amnesia and an explicit episodic-learning system that is compromised. We argue that both tasks reflect the global similarity of probes to memory. In classification, subjects sort unstudied grammatical exemplars from lures, whereas in recognition, they sort studied grammatical exemplars from lures. Hence, global similarity is necessarily greater in recognition than in classification. Moreover, a grammatical exemplar's similarity to studied exemplars is a nonlinear function of the integrity of the data in memory. Assuming that data integrity is better for control subjects than for subjects with amnesia, the nonlinear relation combined with the advantage for recognition over classification predicts the dissociation of recognition and classification. To illustrate the dissociation of recognition and classification in healthy undergraduates, we manipulated study time to vary the integrity of the data in memory and brought the dissociation under experimental control. We argue that the dissociation reflects a general cost in memory rather than a selective impairment of separate procedural and episodic systems. (c) 2010 APA, all rights reserved

Neural Substrates of Spontaneous Musical Performance: An fMRI Study of Jazz Improvisation

PubMed Central

Limb, Charles J.; Braun, Allen R.

2008-01-01

To investigate the neural substrates that underlie spontaneous musical performance, we examined improvisation in professional jazz pianists using functional MRI. By employing two paradigms that differed widely in musical complexity, we found that improvisation (compared to production of over-learned musical sequences) was consistently characterized by a dissociated pattern of activity in the prefrontal cortex: extensive deactivation of dorsolateral prefrontal and lateral orbital regions with focal activation of the medial prefrontal (frontal polar) cortex. Such a pattern may reflect a combination of psychological processes required for spontaneous improvisation, in which internally motivated, stimulus-independent behaviors unfold in the absence of central processes that typically mediate self-monitoring and conscious volitional control of ongoing performance. Changes in prefrontal activity during improvisation were accompanied by widespread activation of neocortical sensorimotor areas (that mediate the organization and execution of musical performance) as well as deactivation of limbic structures (that regulate motivation and emotional tone). This distributed neural pattern may provide a cognitive context that enables the emergence of spontaneous creative activity. PMID:18301756

Neural substrates of spontaneous musical performance: an FMRI study of jazz improvisation.

PubMed

Limb, Charles J; Braun, Allen R

2008-02-27

To investigate the neural substrates that underlie spontaneous musical performance, we examined improvisation in professional jazz pianists using functional MRI. By employing two paradigms that differed widely in musical complexity, we found that improvisation (compared to production of over-learned musical sequences) was consistently characterized by a dissociated pattern of activity in the prefrontal cortex: extensive deactivation of dorsolateral prefrontal and lateral orbital regions with focal activation of the medial prefrontal (frontal polar) cortex. Such a pattern may reflect a combination of psychological processes required for spontaneous improvisation, in which internally motivated, stimulus-independent behaviors unfold in the absence of central processes that typically mediate self-monitoring and conscious volitional control of ongoing performance. Changes in prefrontal activity during improvisation were accompanied by widespread activation of neocortical sensorimotor areas (that mediate the organization and execution of musical performance) as well as deactivation of limbic structures (that regulate motivation and emotional tone). This distributed neural pattern may provide a cognitive context that enables the emergence of spontaneous creative activity.

Dissociable prefrontal brain systems for attention and emotion

NASA Astrophysics Data System (ADS)

Yamasaki, Hiroshi; Labar, Kevin S.; McCarthy, Gregory

2002-08-01

The prefrontal cortex has been implicated in a variety of attentional, executive, and mnemonic mental operations, yet its functional organization is still highly debated. The present study used functional MRI to determine whether attentional and emotional functions are segregated into dissociable prefrontal networks in the human brain. Subjects discriminated infrequent and irregularly presented attentional targets (circles) from frequent standards (squares) while novel distracting scenes, parametrically varied for emotional arousal, were intermittently presented. Targets differentially activated middle frontal gyrus, posterior parietal cortex, and posterior cingulate gyrus. Novel distracters activated inferior frontal gyrus, amygdala, and fusiform gyrus, with significantly stronger activation evoked by the emotional scenes. The anterior cingulate gyrus was the only brain region with equivalent responses to attentional and emotional stimuli. These results show that attentional and emotional functions are segregated into parallel dorsal and ventral streams that extend into prefrontal cortex and are integrated in the anterior cingulate. These findings may have implications for understanding the neural dynamics underlying emotional distractibility on attentional tasks in affective disorders. novelty | prefrontal cortex | amygdala | cingulate gyrus

Analysis of Memory Formation during General Anesthesia (Propofol/Remifentanil) for Elective Surgery Using the Process-dissociation Procedure.

PubMed

Hadzidiakos, Daniel; Horn, Nadja; Degener, Roland; Buchner, Axel; Rehberg, Benno

2009-08-01

There have been reports of memory formation during general anesthesia. The process-dissociation procedure has been used to determine if these are controlled (explicit/conscious) or automatic (implicit/unconscious) memories. This study used the process-dissociation procedure with the original measurement model and one which corrected for guessing to determine if more accurate results were obtained in this setting. A total of 160 patients scheduled for elective surgery were enrolled. Memory for words presented during propofol and remifentanil general anesthesia was tested postoperatively by using a word-stem completion task in a process-dissociation procedure. To assign possible memory effects to different levels of anesthetic depth, the authors measured depth of anesthesia using the BIS XP monitor (Aspect Medical Systems, Norwood, MA). Word-stem completion performance showed no evidence of memory for intraoperatively presented words. Nevertheless, an evaluation of these data using the original measurement model for process-dissociation data suggested an evidence of controlled (C = 0.05; 95% confidence interval [CI] 0.02-0.08) and automatic (A = 0.11; 95% CI 0.09-0.12) memory processes (P < 0.01). However, when the data were evaluated with an extended measurement model taking base rates into account adequately, no evidence for controlled (C = 0.00; 95% CI -0.04 to 0.04) or automatic (A = 0.00; 95% CI -0.02 to 0.02) memory processes was obtained. The authors report and discuss parallel findings for published data sets that were generated by using the process-dissociation procedure. Patients had no memories for auditory information presented during propofol/remifentanil anesthesia after midazolam premedication. The use of the process-dissociation procedure with the original measurement model erroneously detected memories, whereas the extended model, corrected for guessing, correctly revealed no memory.

Childhood Trauma and Dissociative Intimate Partner Violence.

PubMed

Webermann, Aliya R; Murphy, Christopher M

2018-04-01

The present study assesses childhood abuse/neglect as a predictor of dissociative intimate partner violence (IPV) among 118 partner-abusive men. One third (36%) endorsed dissociative IPV, most commonly losing control (18%), surroundings seeming unreal (16%), feeling someone other than oneself is aggressing (16%), and seeing oneself from a distance aggressing (10%). Childhood physical abuse/neglect predicted IPV-specific derealization/depersonalization, aggressive self-states, and flashbacks to past violence. Childhood emotional abuse/neglect predicted derealization/depersonalization, blackouts, and flashbacks. Childhood sexual abuse uniquely predicted amnesia. Other potential traumas did not predict dissociative IPV, suggesting dissociative IPV is influenced by trauma-based emotion dysregulation wherein childhood abuse/neglect survivors disconnect from their abusive behavior.

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

Dysfunctional Metacognitive Beliefs Are Associated with Decreased Executive Control

PubMed Central

Kraft, Brage; Jonassen, Rune; Stiles, Tore C.; Landrø, Nils. I.

2017-01-01

Dysfunctional metacognitive beliefs (“metacognitions”) and executive control are important factors in mental disorders such as depression and anxiety, but the relationship between these concepts has not been studied systematically. We examined whether there is an association between metacognitions and executive control and hypothesized that decreased executive control statistically predicts increased levels of metacognitions. Two hundred and ninety-nine individuals recruited from the general population and outpatient psychiatric clinics completed the Metacognitions Questionnaire-30 and three subtests from the Cambridge Neuropsychological Test Automated Battery corresponding to the three-component model of executive functions. Controlling for current depression and anxiety symptoms, decreased ability to shift between mental sets was associated with increased negative beliefs about the uncontrollability and danger of worry and beliefs about the need to control thoughts. The results suggest a basic association between metacognitions and executive control. Individual differences in executive control could prove important in the personalization of metacognitive therapy. PMID:28469590

An ERP Study of Good Production vis-à-vis Poor Perception of Tones in Cantonese: Implications for Top-Down Speech Processing

PubMed Central

Law, Sam-Po; Fung, Roxana; Kung, Carmen

2013-01-01

This study investigated a theoretically challenging dissociation between good production and poor perception of tones among neurologically unimpaired native speakers of Cantonese. The dissociation is referred to as the near-merger phenomenon in sociolinguistic studies of sound change. In a passive oddball paradigm, lexical and nonlexical syllables of the T1/T6 and T4/T6 contrasts were presented to elicit the mismatch negativity (MMN) and P3a from two groups of participants, those who could produce and distinguish all tones in the language (Control) and those who could produce all tones but specifically failed to distinguish between T4 and T6 in perception (Dissociation). The presence of MMN to T1/T6 and null response to T4/T6 of lexical syllables in the dissociation group confirmed the near-merger phenomenon. The observation that the control participants exhibited a statistically reliable MMN to lexical syllables of T1/T6, weaker responses to nonlexical syllables of T1/T6 and lexical syllables of T4/T6, and finally null response to nonlexical syllables of T4/T6, suggests the involvement of top-down processing in speech perception. Furthermore, the stronger P3a response of the control group, compared with the dissociation group in the same experimental conditions, may be taken to indicate higher cognitive capability in attention switching, auditory attention or memory in the control participants. This cognitive difference, together with our speculation that constant top-down predictions without complete bottom-up analysis of acoustic signals in speech recognition may reduce one’s sensitivity to small acoustic contrasts, account for the occurrence of dissociation in some individuals but not others. PMID:23342146

An ERP study of good production vis-à-vis poor perception of tones in Cantonese: implications for top-down speech processing.

PubMed

Law, Sam-Po; Fung, Roxana; Kung, Carmen

2013-01-01

This study investigated a theoretically challenging dissociation between good production and poor perception of tones among neurologically unimpaired native speakers of Cantonese. The dissociation is referred to as the near-merger phenomenon in sociolinguistic studies of sound change. In a passive oddball paradigm, lexical and nonlexical syllables of the T1/T6 and T4/T6 contrasts were presented to elicit the mismatch negativity (MMN) and P3a from two groups of participants, those who could produce and distinguish all tones in the language (Control) and those who could produce all tones but specifically failed to distinguish between T4 and T6 in perception (Dissociation). The presence of MMN to T1/T6 and null response to T4/T6 of lexical syllables in the dissociation group confirmed the near-merger phenomenon. The observation that the control participants exhibited a statistically reliable MMN to lexical syllables of T1/T6, weaker responses to nonlexical syllables of T1/T6 and lexical syllables of T4/T6, and finally null response to nonlexical syllables of T4/T6, suggests the involvement of top-down processing in speech perception. Furthermore, the stronger P3a response of the control group, compared with the dissociation group in the same experimental conditions, may be taken to indicate higher cognitive capability in attention switching, auditory attention or memory in the control participants. This cognitive difference, together with our speculation that constant top-down predictions without complete bottom-up analysis of acoustic signals in speech recognition may reduce one's sensitivity to small acoustic contrasts, account for the occurrence of dissociation in some individuals but not others.

Temporal analysis of nonresonant two-photon coherent control involving bound and dissociative molecular states

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

Su Jing; Chen Shaohao; Jaron-Becker, Agnieszka

We theoretically study the control of two-photon excitation to bound and dissociative states in a molecule induced by trains of laser pulses, which are equivalent to certain sets of spectral phase modulated pulses. To this end, we solve the time-dependent Schroedinger equation for the interaction of molecular model systems with an external intense laser field. Our numerical results for the temporal evolution of the population in the excited states show that, in the case of an excited dissociative state, control schemes, previously validated for the atomic case, fail due to the coupling of electronic and nuclear motion. In contrast, formore » excitation to bound states the two-photon excitation probability is controlled via the time delay and the carrier-envelope phase difference between two consecutive pulses in the train.« less

Domain-specific control mechanisms for emotional and nonemotional conflict processing.

PubMed

Soutschek, Alexander; Schubert, Torsten

2013-02-01

Recent neuroimaging studies suggest that the human brain activates dissociable cognitive control networks in response to conflicts arising within the cognitive and the affective domain. The present study tested the hypothesis that nonemotional and emotional conflict regulation can also be dissociated on a functional level. For that purpose, we examined the effects of a working memory and an emotional Go/Nogo task on cognitive control in an emotional and a nonemotional variant of the Stroop paradigm. The data confirmed the hypothesized dissociation: Working memory efforts selectively suppressed conflict regulation in the nonemotional Stroop task, while the demands of an emotional Go/Nogo task impaired only conflict regulation in the emotional Stroop task. We conclude that these findings support a modular architecture of cognitive control with domain-specific conflict regulation processes. Copyright © 2012 Elsevier B.V. All rights reserved.

Bidirectional Frontoparietal Oscillatory Systems Support Working Memory.

PubMed

Johnson, Elizabeth L; Dewar, Callum D; Solbakk, Anne-Kristin; Endestad, Tor; Meling, Torstein R; Knight, Robert T

2017-06-19

The ability to represent and select information in working memory provides the neurobiological infrastructure for human cognition. For 80 years, dominant views of working memory have focused on the key role of prefrontal cortex (PFC) [1-8]. However, more recent work has implicated posterior cortical regions [9-12], suggesting that PFC engagement during working memory is dependent on the degree of executive demand. We provide evidence from neurological patients with discrete PFC damage that challenges the dominant models attributing working memory to PFC-dependent systems. We show that neural oscillations, which provide a mechanism for PFC to communicate with posterior cortical regions [13], independently subserve communications both to and from PFC-uncovering parallel oscillatory mechanisms for working memory. Fourteen PFC patients and 20 healthy, age-matched controls performed a working memory task where they encoded, maintained, and actively processed information about pairs of common shapes. In controls, the electroencephalogram (EEG) exhibited oscillatory activity in the low-theta range over PFC and directional connectivity from PFC to parieto-occipital regions commensurate with executive processing demands. Concurrent alpha-beta oscillations were observed over parieto-occipital regions, with directional connectivity from parieto-occipital regions to PFC, regardless of processing demands. Accuracy, PFC low-theta activity, and PFC → parieto-occipital connectivity were attenuated in patients, revealing a PFC-independent, alpha-beta system. The PFC patients still demonstrated task proficiency, which indicates that the posterior alpha-beta system provides sufficient resources for working memory. Taken together, our findings reveal neurologically dissociable PFC and parieto-occipital systems and suggest that parallel, bidirectional oscillatory systems form the basis of working memory. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Vortioxetine reduces BOLD signal during performance of the N-back working memory task: a randomised neuroimaging trial in remitted depressed patients and healthy controls

PubMed Central

Smith, J; Browning, M; Conen, S; Smallman, R; Buchbjerg, J; Larsen, K G; Olsen, C K; Christensen, S R; Dawson, G R; Deakin, J F; Hawkins, P; Morris, R; Goodwin, G; Harmer, C J

2018-01-01

Cognitive dysfunction is common in depression during both acute episodes and remission. Vortioxetine is a novel multimodal antidepressant that has improved cognitive function including executive function in depressed patients in randomised placebo-controlled clinical trials. However, it is unclear whether vortioxetine is able to target directly the neural circuitry implicated in the cognitive deficits in depression. Remitted depressed (n=48) and healthy volunteers (n=48) were randomised to receive 14 days treatment with 20 mg vortioxetine or placebo in a double-blind design. The effects of treatment on functional magnetic resonance imaging responses during an N-back working memory task were assessed at baseline and at the end of treatment. Neuropsychological measures of executive function, speed and information processing, attention and learning and memory were examined with the Trail Making Test (TMT), Rey Auditory Learning Test and Digit Symbol Substitution Test before and after treatment; subjective cognitive function was assessed using the Perceived Deficits Questionnaire (PDQ). Compared with placebo, vortioxetine reduced activation in the right dorsolateral prefrontal cortex and left hippocampus during the N-back task compared with placebo. Vortioxetine also increased TMT-A performance and self-reported cognitive function on the PDQ. These effects were seen across both subject groups. Vortioxetine modulates neural responses across a circuit subserving working memory in a direction opposite to the changes described in depression, when performance is maintained. This study provides evidence that vortioxetine has direct effects on the neural circuitry supporting cognitive function that can be dissociated from its effects on the mood symptoms of depression. PMID:28533517

Dissociation of decision making under ambiguity and decision making under risk in breast cancer patients receiving adjuvant chemotherapy: a neuropsychological study.

PubMed

Chen, Xingui; Zhu, Chunyan; Li, Jingjing; Qiu, Linlin; Zhang, Long; Yu, Fengqiong; Ye, Rong; Zhang, Jingjie; Wang, Kai

2013-10-02

There is evidence that women with breast cancer show a cognitive impairment after having undergone chemotherapy treatment; this cognitive impairment may result in behavioral deficits. However, the neural mechanism of this cognitive impairment remains unclear. The present study investigated the neural basis of the cognitive impairment caused by chemotherapy treatment by exploring the decision-making function of the executive subcomponents under ambiguity and risk in breast cancer survivors. Participants included breast cancer patients who had undergone chemotherapy (CT, N=63) or patients who did not undergo chemotherapy (non-CT, N=62), as well as matched healthy controls (HC, N=61). All participants were examined using the Iowa Gambling Task (IGT) to assess their decision-making under ambiguity, the Game of Dice Task (GDT) to assess their decision-making under risk and neuropsychological background tests. Our results indicated that during the IGT test, the chemotherapy-treated breast cancer patients selected from the disadvantageous decks with a higher frequency than the non-treated breast cancer patients or healthy controls, whereas all three groups performed at the same level when performing the GDT. The CT group demonstrated significantly lower scores in several cognitive tasks, including attention, memory, executive functions and cognitive processing, when compared with the other two groups. In addition, within the CT group, significant correlations were found between the IGT performance and information processing, as well as with working memory. This study demonstrated that breast cancer survivors treated with chemotherapy may have selective reductions in IGT performance but unimpaired GDT performance and that these deficits may result from dysfunctions in the limbic loop rather than in the dorsolateral prefrontal loop. © 2013 Elsevier B.V. All rights reserved.

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.

Dissociative subtype of DSM-5 posttraumatic stress disorder in U.S. veterans.

PubMed

Tsai, Jack; Armour, Cherie; Southwick, Steven M; Pietrzak, Robert H

2015-01-01

The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) formally introduced a dissociative subtype of posttraumatic stress disorder (PTSD). This study examined the proportion of U.S. veterans with DSM-5 PTSD that report dissociative symptoms; and compared veterans with PTSD with and without the dissociative subtype and trauma-exposed controls on sociodemographics, clinical characteristics, and quality of life. Multivariable analyses were conducted on a nationally representative sample of 1484 veterans from the National Health and Resilience in Veterans Study (second baseline survey conducted September-October, 2013). Of the 12.0% and 5.2% of veterans who screened positive for lifetime and past-month DSM-5 PTSD, 19.2% and 16.1% screened positive for the dissociative subtype, respectively. Among veterans with PTSD, those with the dissociative subtype reported more severe PTSD symptoms, comorbid depressive and anxiety symptoms, alcohol use problems, and hostility than those without the dissociative subtype. Adjusting for PTSD symptom severity, those with the dissociative subtype continued to report more depression and alcohol use problems. These results underscore the importance of assessing, monitoring, and treating the considerable proportion of veterans with PTSD and dissociative symptoms. Published by Elsevier Ltd.

Memory-guided saccade processing in visual form agnosia (patient DF).

PubMed

Rossit, Stéphanie; Szymanek, Larissa; Butler, Stephen H; Harvey, Monika

2010-01-01

According to Milner and Goodale's model (The visual brain in action, Oxford University Press, Oxford, 2006) areas in the ventral visual stream mediate visual perception and oV-line actions, whilst regions in the dorsal visual stream mediate the on-line visual control of action. Strong evidence for this model comes from a patient (DF), who suffers from visual form agnosia after bilateral damage to the ventro-lateral occipital region, sparing V1. It has been reported that she is normal in immediate reaching and grasping, yet severely impaired when asked to perform delayed actions. Here we investigated whether this dissociation would extend to saccade execution. Neurophysiological studies and TMS work in humans have shown that the posterior parietal cortex (PPC), on the right in particular (supposedly spared in DF), is involved in the control of memory-guided saccades. Surprisingly though, we found that, just as reported for reaching and grasping, DF's saccadic accuracy was much reduced in the memory compared to the stimulus-guided condition. These data support the idea of a tight coupling of eye and hand movements and further suggest that dorsal stream structures may not be sufficient to drive memory-guided saccadic performance.

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.

Executive Control Mediates the Association Between Aerobic Fitness and Emotion Regulation in Preadolescent Children.

PubMed

Lott, Mark A; Jensen, Chad D

2017-03-01

This study evaluated direct and indirect associations between aerobic fitness, executive control, and emotion regulation among a community sample of preadolescent children. Two-hundred and seventy-eight children aged 8-12 years completed measures of aerobic fitness (Progressive Aerobic Cardiovascular Endurance Run) and executive control (Stroop Test). Parents completed questionnaires assessing child emotion regulation and executive control (Emotion Regulation Checklist; Early Adolescent Temperament Questionnaire). We evaluated associations between these constructs using structural equation modeling. Study findings supported a moderate direct association between childhood aerobic fitness and executive control, a strong direct negative association between executive control and emotion regulation, and a moderate indirect association between aerobic fitness and emotion regulation through executive control. These findings provide preliminary evidence that executive control functions as a mediator between aerobic fitness and emotion regulation and may help explain the mechanism by which aerobic exercise influences emotional well-being among preadolescent children. © The Author 2016. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

“No-o-o-o Peeking”: Preschoolers’ Executive Control, Social Competence, and Classroom Adjustment

PubMed Central

Denham, Susanne A.; Bassett, Hideko H.; Sirotkin, Yana S.; Brown, Chavaughn; Morris, Carol S.

2015-01-01

The goals of this study were to evaluate (1) how specific aspects of executive control, briefly assessed, predict social competence and classroom adjustment during preschool; and (2) differences between two aspects of executive control, according to child’s age, socioeconomic risk status, and gender. The facets of executive control were defined as cool executive control (CEC; affectively neutral, slow acting, and late developing) and hot executive control (HEC; more emotional, fast acting, and early developing). Two hundred eighty-seven 3- to 5-year-old children from private child care and Head Start centers were directly assessed during executive control tasks, and preschool teachers provided information on their school success. Aspects of executive control varied with age, socioeconomic risk, and gender. Specifically, older children performed better on CEC tasks across three age levels; for HEC tasks, change was seen only between 3-year-olds and 4-year-olds. Children of mothers with less formal education performed less well on CEC than those whose mothers had more education; girls performed better than boys on HEC tasks. Further, facets of executive control were differentially related to later social competence and classroom adjustment. HEC predicted social competence, whereas CEC uniquely predicted classroom adjustment. Implications for everyday practice and specific curricula formulation are discussed. PMID:26166925

Axis-I comorbidity in female patients with dissociative identity disorder and dissociative identity disorder not otherwise specified.

PubMed

Rodewald, Frauke; Wilhelm-Göling, Claudia; Emrich, Hinderk M; Reddemann, Luise; Gast, Ursula

2011-02-01

The aim of this study was to investigate axis-I comorbidity in patients with dissociative identity disorder (DID) and dissociative disorder not otherwise specified (DDNOS). Using the Diagnostic Interview for Psychiatric Disorders, results from patients with DID (n = 44) and DDNOS (n = 22) were compared with those of patients with posttraumatic stress disorder (PTSD) (n = 13), other anxiety disorders (n = 14), depression (n = 17), and nonclinical controls (n = 30). No comorbid disorders were found in nonclinical controls. The average number of comorbid disorders in patients with depression or anxiety was 0 to 2. Patients with dissociative disorders averagely suffered from 5 comorbid disorders. The most prevalent comorbidity in DDNOS and DID was PTSD. Comorbidity profiles of patients with DID and DDNOS were very similar to those in PTSD (high prevalence of anxiety, somatoform disorders, and depression), but differed significantly from those of patients with depression and anxiety disorders. These findings confirm the hypothesis that PTSD, DID, and DDNOS are phenomenologically related syndromes that should be summarized within a new diagnostic category.

Dissociative part-dependent resting-state activity in dissociative identity disorder: a controlled FMRI perfusion study.

PubMed

Schlumpf, Yolanda R; Reinders, Antje A T S; Nijenhuis, Ellert R S; Luechinger, Roger; van Osch, Matthias J P; Jäncke, Lutz

2014-01-01

In accordance with the Theory of Structural Dissociation of the Personality (TSDP), studies of dissociative identity disorder (DID) have documented that two prototypical dissociative subsystems of the personality, the "Emotional Part" (EP) and the "Apparently Normal Part" (ANP), have different biopsychosocial reactions to supraliminal and subliminal trauma-related cues and that these reactions cannot be mimicked by fantasy prone healthy controls nor by actors. Arterial spin labeling perfusion MRI was used to test the hypotheses that ANP and EP in DID have different perfusion patterns in response to rest instructions, and that perfusion is different in actors who were instructed to simulate ANP and EP. In a follow-up study, regional cerebral blood flow of DID patients was compared with the activation pattern of healthy non-simulating controls. Compared to EP, ANP showed elevated perfusion in bilateral thalamus. Compared to ANP, EP had increased perfusion in the dorsomedial prefrontal cortex, primary somatosensory cortex, and motor-related areas. Perfusion patterns for simulated ANP and EP were different. Fitting their reported role-play strategies, the actors activated brain structures involved in visual mental imagery and empathizing feelings. The follow-up study demonstrated elevated perfusion in the left temporal lobe in DID patients, whereas non-simulating healthy controls had increased activity in areas which mediate the mental construction of past and future episodic events. DID involves dissociative part-dependent resting-state differences. Compared to ANP, EP activated brain structures involved in self-referencing and sensorimotor actions more. Actors had different perfusion patterns compared to genuine ANP and EP. Comparisons of neural activity for individuals with DID and non-DID simulating controls suggest that the resting-state features of ANP and EP in DID are not due to imagination. The findings are consistent with TSDP and inconsistent with the idea that DID is caused by suggestion, fantasy proneness, and role-playing.

Dissociative Part-Dependent Resting-State Activity in Dissociative Identity Disorder: A Controlled fMRI Perfusion Study

PubMed Central

Schlumpf, Yolanda R.; Reinders, Antje A. T. S.; Nijenhuis, Ellert R. S.; Luechinger, Roger; van Osch, Matthias J. P.; Jäncke, Lutz

2014-01-01

Background In accordance with the Theory of Structural Dissociation of the Personality (TSDP), studies of dissociative identity disorder (DID) have documented that two prototypical dissociative subsystems of the personality, the “Emotional Part” (EP) and the “Apparently Normal Part” (ANP), have different biopsychosocial reactions to supraliminal and subliminal trauma-related cues and that these reactions cannot be mimicked by fantasy prone healthy controls nor by actors. Methods Arterial spin labeling perfusion MRI was used to test the hypotheses that ANP and EP in DID have different perfusion patterns in response to rest instructions, and that perfusion is different in actors who were instructed to simulate ANP and EP. In a follow-up study, regional cerebral blood flow of DID patients was compared with the activation pattern of healthy non-simulating controls. Results Compared to EP, ANP showed elevated perfusion in bilateral thalamus. Compared to ANP, EP had increased perfusion in the dorsomedial prefrontal cortex, primary somatosensory cortex, and motor-related areas. Perfusion patterns for simulated ANP and EP were different. Fitting their reported role-play strategies, the actors activated brain structures involved in visual mental imagery and empathizing feelings. The follow-up study demonstrated elevated perfusion in the left temporal lobe in DID patients, whereas non-simulating healthy controls had increased activity in areas which mediate the mental construction of past and future episodic events. Conclusion DID involves dissociative part-dependent resting-state differences. Compared to ANP, EP activated brain structures involved in self-referencing and sensorimotor actions more. Actors had different perfusion patterns compared to genuine ANP and EP. Comparisons of neural activity for individuals with DID and non-DID simulating controls suggest that the resting-state features of ANP and EP in DID are not due to imagination. The findings are consistent with TSDP and inconsistent with the idea that DID is caused by suggestion, fantasy proneness, and role-playing. PMID:24922512

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.

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.

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.

"No-o-o-o Peeking": Preschoolers' Executive Control, Social Competence, and Classroom Adjustment

ERIC Educational Resources Information Center

Denham, Susanne A.; Bassett, Hideko H.; Sirotkin, Yana S.; Brown, Chavaughn; Morris, Carol S.

2015-01-01

The goals of this study were to evaluate (1) how specific aspects of executive control, briefly assessed, predict social competence and classroom adjustment during preschool and (2) differences between two aspects of executive control, according to child's age, socioeconomic risk status, and gender. The facets of executive control were defined as…

The impact of dissociation on perceptual priming and intrusions after listening to auditory narratives.

PubMed

Dorahy, Martin J; Peck, Rowan K; Huntjens, Rafaele J C

2016-01-01

This study investigates the causal role of dissociation in intrusive memory development and possible underlying aberrant memory processes (e.g., increased perceptual priming). Using an audio-only adaption of the trauma film paradigm, we divided 60 participants into 3 conditions and presented them with different visual tasks-mirror staring, dot staring, or neutral images. The former 2 conditions were hypothesized to induce dissociation. Postaudio, a number of factors were assessed, including state dissociation, perceptual priming and conceptual priming, as well as intrusions over 3 days. Participants in the dissociation conditions displayed an increase in perceptual priming compared to those in the control condition and reported more distressing intrusions. No differences were found in conceptual priming and the overall number of intrusions between conditions. Findings contribute to the growing knowledge on the impact of dissociation and cognitive processing in the etiology of posttraumatic stress disorder intrusions.

The Caspase-8 Dimerization/Dissociation Balance Is a Highly Potent Regulator of Caspase-8, -3, -6 Signaling*

PubMed Central

Würstle, Maximilian L.; Laussmann, Maike A.; Rehm, Markus

2010-01-01

Apoptosis is driven by positive feedback activation between aspartate-specific cysteinyl proteases (caspases). These feedback loops ensure the swift and efficient elimination of cells upon initiation of apoptosis execution. At the same time, the signaling network must be insensitive to erroneous, mild caspase activation to avoid unwanted, excessive cell death. Sublethal caspase activation in fact was shown to be a requirement for the differentiation of multiple cell types but might also occur accidentally during short, transient cellular stress conditions. Here we carried out an in silico comparison of the molecular mechanisms that so far have been identified to impair the amplification of caspase activities via the caspase-8, -3, -6 loop. In a systems model resembling HeLa cervical cancer cells, the dimerization/dissociation balance of caspase-8 potently suppressed the amplification of caspase responses, surprisingly outperforming or matching known caspase-8 and -3 inhibitors such as bifunctional apoptosis repressor or x-linked inhibitor of apoptosis protein. These findings were further substantiated in global sensitivity analyses based on combinations of protein concentrations from the sub- to superphysiological range to screen the full spectrum of biological variability that can be expected within cell populations and between distinct cell types. Additional modeling showed that the combined effects of x-linked inhibitor of apoptosis protein and caspase-8 dimerization/dissociation processes can also provide resistance to larger inputs of active caspases. Our study therefore highlights a central and so far underappreciated role of caspase-8 dimerization/dissociation in avoiding unwanted cell death by lethal amplification of caspase responses via the caspase-8, -3, -6 loop. PMID:20702410

Terminal decline and practice effects in older adults without dementia: the MoVIES project.

PubMed

Dodge, Hiroko H; Wang, Chia-Ning; Chang, Chung-Chou H; Ganguli, Mary

2011-08-23

To track cognitive change over time in dementia-free older adults and to examine terminal cognitive decline. A total of 1,230 subjects who remained free from dementia over 14 years of follow-up were included in a population-based epidemiologic cohort study. First, we compared survivors and decedents on their trajectories of 5 cognitive functions (learning, memory, language, psychomotor speed, executive functions), dissociating practice effects which can mask clinically significant decline from age-associated cognitive decline. We used longitudinal mixed-effects models with penalized linear spline. Second, limiting the sample to 613 subjects who died during follow-up, we identified the inflection points at which the rate of cognitive decline accelerated, in relation to time of death, controlling for practice effects. We used mixed-effects model with a change point. Age-associated cognitive trajectories were similar between decedents and survivors without dementia. However, substantial differences were observed between the trajectories of practice effects of survivors and decedents, resembling those usually observed between normal and mildly cognitively impaired elderly. Executive and language functions showed the earliest terminal declines, more than 9 years prior to death, independent of practice effects. Terminal cognitive decline in older adults without dementia may reflect presymptomatic disease which does not cross the clinical threshold during life. Alternatively, cognitive decline attributed to normal aging may itself represent underlying neurodegenerative or vascular pathology. Although we cannot conclude definitively from this study, the separation of practice effects from age-associated decline could help identify preclinical dementia.

Conceptualizing neuropsychiatric diseases with multimodal data-driven meta-analyses – The case of behavioral variant frontotemporal dementia

PubMed Central

Schroeter, Matthias L.; Laird, Angela R.; Chwiesko, Caroline; Deuschl, Christine; Schneider, Else; Bzdok, Danilo; Eickhoff, Simon B.; Neumann, Jane

2014-01-01

Introduction Uniform coordinate systems in neuroimaging research have enabled comprehensive systematic and quantitative meta-analyses. Such approaches are particularly relevant for neuropsychiatric diseases, the understanding of their symptoms, prediction and treatment. Behavioral variant frontotemporal dementia (bvFTD), a common neurodegenerative syndrome, is characterized by deep alterations in behavior and personality. Investigating this ‘nexopathy’ elucidates the healthy social and emotional brain. Methods Here, we combine three multimodal meta-analyses approaches – anatomical & activation likelihood estimates and behavioral domain profiles – to identify neural correlates of bvFTD in 417 patients and 406 control subjects and to extract mental functions associated with this disease by meta-analyzing functional activation studies in the comprehensive probabilistic functional brain atlas of the BrainMap database. Results The analyses identify the frontomedian cortex, basal ganglia, anterior insulae and thalamus as most relevant hubs, with a regional dissociation between atrophy and hypometabolism. Neural networks affected by bvFTD were associated with emotion and reward processing, empathy and executive functions (mainly inhibition), suggesting these functions as core domains affected by the disease and finally leading to its clinical symptoms. In contrast, changes in theory of mind or mentalizing abilities seem to be secondary phenomena of executive dysfunctions. Conclusions The study creates a novel conceptual framework to understand neuropsychiatric diseases by powerful data-driven meta-analytic approaches that shall be extended to the whole neuropsychiatric spectrum in the future. PMID:24763126

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.

A dissociation between stopping and switching actions following a lesion of the pre-supplementary motor area

PubMed Central

Roberts, R. Edward; Husain, Masud

2015-01-01

Introduction Although the pre-supplementary motor area (pre-SMA) is one of the most frequently reported areas of activation in functional imaging studies, the role of this brain region in cognition is still a matter of intense debate. Here we present a patient with a focal lesion of caudal pre-SMA who displays a selective deficit in updating a response plan to switch actions, but shows no impairment when required to withhold a response – stopping. Materials & methods The patient and a control group underwent three tasks designed to measure different aspects of cognitive control and executive function. Results The pre-SMA patient displayed no impairment when responding in the face of distracting stimuli (Eriksen flanker paradigm), or when required to halt an on-going response (STOP task). However, a specific deficit was observed when she was required to rapidly switch between response plans (CHANGE task). Conclusions These findings suggest that the caudal pre-SMA may have a particularly important role in a network of brain regions required for rapidly updating and implementing response plans. The lack of any significant impairment on other measures of cognitive control suggests that this is not likely due to a global deficit in cognitive control. We discuss the implications of these results in the context of current theories of pre-SMA function. PMID:25282056

Threat facilitates subsequent executive control during anxious mood.

PubMed

Birk, Jeffrey L; Dennis, Tracy A; Shin, Lisa M; Urry, Heather L

2011-12-01

Dual competition framework (DCF) posits that low-level threat may facilitate behavioral performance by influencing executive control functions. Anxiety is thought to strengthen this effect by enhancing threat's affective significance. To test these ideas directly, we examined the effects of low-level threat and experimentally induced anxiety on one executive control function, the efficiency of response inhibition. In Study 1, briefly presented stimuli that were mildly threatening (i.e., fearful faces) relative to nonthreatening (i.e., neutral faces) led to facilitated executive control efficiency during experimentally induced anxiety. No such effect was observed during an equally arousing, experimentally induced happy mood state. In Study 2, we assessed the effects of low-level threat, experimentally induced anxiety, and individual differences in trait anxiety on executive control efficiency. Consistent with Study 1, fearful relative to neutral faces led to facilitated executive control efficiency during experimentally induced anxiety. No such effect was observed during an experimentally induced neutral mood state. Moreover, individual differences in trait anxiety did not moderate the effects of threat and anxiety on executive control efficiency. The findings are partially consistent with the predictions of DCF in that low-level threat improved executive control, at least during a state of anxiety. (c) 2011 APA, all rights reserved.

Gene Expression in Pre-MBT Embryos and Activation of Maternally-Inherited Program of Apoptosis to be Executed at around MBT as a Fail-Safe Mechanism in Xenopus Early Embryogenesis

PubMed Central

Shiokawa, Koichiro; Aso, Mai; Kondo, Takeshi; Uchiyama, Hiroaki; Kuroyanagi, Shinsaku; Takai, Jun-Ichi; Takahashi, Senji; Kajitani, Masayuki; Kaito, Chikara; Sekimizu, Kazuhisa; Takayama, Eiji; Igarashi, Kazuei; Hara, Hiroshi

2008-01-01

S-adenosylmethionine decarboxylase (SAMDC) is an enzyme which converts S-adenosylmethione (SAM), a methyl donor, to decarboxylated SAM (dcSAM), an aminopropyl donor for polyamine biosynthesis. In our studies on gene expression control in Xenopus early embryogenesis, we cloned the mRNA for Xenopus SAMDC, and overexpressed the enzyme by microinjecting its mRNA into Xenopus fertilized eggs. In the mRNA-injected embryos, the level of SAMDC was enormously increased, the SAM was exhausted, and protein synthesis was greatly inhibited, but cellular polyamine content did not change appreciably. SAMDC-overexpressed embryos cleaved and developed normally up to the early blastula stage, but at the midblastula stage, or the stage of midblastula transition (MBT), all the embryos were dissociated into cells, and destroyed due to execution of apoptosis. During cleavage SAMDC-overexpressed embryos transcribed caspase-8 gene, and this was followed by activation of caspase-9. When we overexpressed p53 mRNA in fertilized eggs, similar apoptosis took place at MBT, but in this case, transcription of caspase-8 did not occur, however activation of caspase-9 took place. Apoptosis induced by SAMDC-overexpression was completely suppressed by Bcl-2, whereas apoptosis induced by p53 overexpression or treatments with other toxic agents was only partially rescued. When we injected SAMDC mRNA into only one blastomere of 8- to 32-celled embryos, descendant cells of the mRNA-injected blastomere were segregated into the blastocoel and underwent apoptosis within the blastocoel, although such embryos continued to develop and became tadpoles with various extents of anomaly, reflecting the developmental fate of the eliminated cells. Thus, embryonic cells appear to check themselves at MBT and if physiologically severely-damaged cells occur, they are eliminated from the embryo by activation and execution of the maternally-inherited program of apoptosis. We assume that the apoptosis executed at MBT is a “fail-safe” mechanism of early development to save the embryo from accidental damages that take place during cleavage. PMID:19787085

What makes your brain suggestible? Hypnotizability is associated with differential brain activity during attention outside hypnosis.

PubMed

Cojan, Yann; Piguet, Camille; Vuilleumier, Patrik

2015-08-15

Theoretical models of hypnosis have emphasized the importance of attentional processes in accounting for hypnotic phenomena but their exact nature and brain substrates remain unresolved. Individuals vary in their susceptibility to hypnosis, a variability often attributed to differences in attentional functioning such as greater ability to filter irrelevant information and inhibit prepotent responses. However, behavioral studies of attentional performance outside the hypnotic state have provided conflicting results. We used fMRI to investigate the recruitment of attentional networks during a modified flanker task in High and Low hypnotizable participants. The task was performed in a normal (no hypnotized) state. While behavioral performance did not reliably differ between groups, components of the fronto-parietal executive network implicated in monitoring (anterior cingulate cortex; ACC), adjustment (lateral prefrontal cortex; latPFC), and implementation of attentional control (intraparietal sulcus; IPS) were differently activated depending on the hypnotizability of the subjects: the right inferior frontal gyrus (rIFG) was more recruited, whereas IPS and ACC were less recruited by High susceptible individuals compared to Low. Our results demonstrate that susceptibility to hypnosis is associated with particular executive control capabilities allowing efficient attentional focusing, and point to specific neural substrates in right prefrontal cortex. We demonstrated that outside hypnosis, low hypnotizable subjects recruited more parietal cortex and anterior cingulate regions during selective attention conditions suggesting a better detection and implementation of conflict. However, outside hypnosis the right inferior frontal gyrus (rIFG) was more recruited by highly hypnotizable subjects during selective attention conditions suggesting a better control of conflict. Furthermore, in highly hypnotizable subjects this region was more connected to the default mode network suggesting a tight dialogue between internally and externally driven processes that may permit higher flexibility in attention and underlie a greater ability to dissociate. Copyright © 2015 Elsevier Inc. All rights reserved.

Concurrent Path Planning with One or More Humanoid Robots

NASA Technical Reports Server (NTRS)

Reiland, Matthew J. (Inventor); Sanders, Adam M. (Inventor)

2014-01-01

A robotic system includes a controller and one or more robots each having a plurality of robotic joints. Each of the robotic joints is independently controllable to thereby execute a cooperative work task having at least one task execution fork, leading to multiple independent subtasks. The controller coordinates motion of the robot(s) during execution of the cooperative work task. The controller groups the robotic joints into task-specific robotic subsystems, and synchronizes motion of different subsystems during execution of the various subtasks of the cooperative work task. A method for executing the cooperative work task using the robotic system includes automatically grouping the robotic joints into task-specific subsystems, and assigning subtasks of the cooperative work task to the subsystems upon reaching a task execution fork. The method further includes coordinating execution of the subtasks after reaching the task execution fork.

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

Clustering execution in a processing system to increase power savings

DOEpatents

Bose, Pradip; Buyuktosunoglu, Alper; Jacobson, Hans M.; Vega, Augusto J.

2018-03-20

Embodiments relate to clustering execution in a processing system. An aspect includes accessing a control flow graph that defines a data dependency and an execution sequence of a plurality of tasks of an application that executes on a plurality of system components. The execution sequence of the tasks in the control flow graph is modified as a clustered control flow graph that clusters active and idle phases of a system component while maintaining the data dependency. The clustered control flow graph is sent to an operating system, where the operating system utilizes the clustered control flow graph for scheduling the tasks.

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.

Inter-relationships between objective handwriting features and executive control among children with developmental dysgraphia.

PubMed

Rosenblum, Sara

2018-01-01

To describe handwriting and executive control features and their inter-relationships among children with developmental dysgraphia, in comparison to controls. Participants included 64 children, aged 10-12 years, 32 with dysgraphia based on the Handwriting Proficiency Screening Questionnaire (HPSQ) and 32 matched controls. Children copied a paragraph onto paper affixed to a digitizer that supplied handwriting process objective measures (Computerized Penmanship Evaluation Tool (ComPET). Their written product was evaluated by the Hebrew Handwriting Evaluation (HHE). Parents completed the Behavior Rating Inventory of Executive Function (BRIEF) questionnaire about their child's executive control abilities. Significant group differences were found for handwriting performance measures (HHE and ComPET) and executive control domains (BRIEF). Based on one discriminate function, including handwriting performance and executive control measures, 98.4% of the participants were correctly classified into groups. Significant correlations were found in each group between working memory and legibility as well as for other executive domains and handwriting measures. Furthermore, twenty percent of the variability of the mean pressure applied towards the writing surface among children with was explained by their 'emotional control' (BRIEF). The results strongly suggest consideration of executive control domains to obtain better insight into handwriting impairment characteristics among children with dysgraphia to improve their identification, evaluation and the intervention process.

Inter-relationships between objective handwriting features and executive control among children with developmental dysgraphia

PubMed Central

2018-01-01

Objective To describe handwriting and executive control features and their inter-relationships among children with developmental dysgraphia, in comparison to controls. Method Participants included 64 children, aged 10–12 years, 32 with dysgraphia based on the Handwriting Proficiency Screening Questionnaire (HPSQ) and 32 matched controls. Children copied a paragraph onto paper affixed to a digitizer that supplied handwriting process objective measures (Computerized Penmanship Evaluation Tool (ComPET). Their written product was evaluated by the Hebrew Handwriting Evaluation (HHE). Parents completed the Behavior Rating Inventory of Executive Function (BRIEF) questionnaire about their child's executive control abilities. Results Significant group differences were found for handwriting performance measures (HHE and ComPET) and executive control domains (BRIEF). Based on one discriminate function, including handwriting performance and executive control measures, 98.4% of the participants were correctly classified into groups. Significant correlations were found in each group between working memory and legibility as well as for other executive domains and handwriting measures. Furthermore, twenty percent of the variability of the mean pressure applied towards the writing surface among children with was explained by their 'emotional control' (BRIEF). Conclusion The results strongly suggest consideration of executive control domains to obtain better insight into handwriting impairment characteristics among children with dysgraphia to improve their identification, evaluation and the intervention process. PMID:29689111

Synchrony of corticostriatal-midbrain activation enables normal inhibitory control and conflict processing in recovering alcoholic men.

PubMed

Schulte, Tilman; Müller-Oehring, Eva M; Sullivan, Edith V; Pfefferbaum, Adolf

2012-02-01

Alcohol dependence is associated with inhibitory control deficits, possibly related to abnormalities in frontoparietal cortical and midbrain function and connectivity. We examined functional connectivity and microstructural fiber integrity between frontoparietal and midbrain structures using a Stroop Match-to-Sample task with functional magnetic resonance imaging and diffusion tensor imaging in 18 alcoholic and 17 control subjects. Manipulation of color cues and response repetition sequences modulated cognitive demands during Stroop conflict. Despite similar lateral frontoparietal activity and functional connectivity in alcoholic and control subjects when processing conflict, control subjects deactivated the posterior cingulate cortex (PCC), whereas alcoholic subjects did not. Posterior cingulum fiber integrity predicted the degree of PCC deactivation in control but not alcoholic subjects. Also, PCC activity was modulated by executive control demands: activated during response switching and deactivated during response repetition. Alcoholics showed the opposite pattern: activation during repetition and deactivation during switching. Here, in alcoholic subjects, greater deviations from the normal PCC activity correlated with higher amounts of lifetime alcohol consumption. A functional dissociation of brain network connectivity between the groups further showed that control subjects exhibited greater corticocortical connectivity among middle cingulate, posterior cingulate, and medial prefrontal cortices than alcoholic subjects. In contrast, alcoholic subjects exhibited greater midbrain-orbitofrontal cortical network connectivity than control subjects. Degree of microstructural fiber integrity predicted robustness of functional connectivity. Thus, even subtle compromise of microstructural connectivity in alcoholism can influence modulation of functional connectivity and underlie alcohol-related cognitive impairment. Copyright © 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

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 Jet Propulsion Laboratory shared control architecture and implementation

NASA Technical Reports Server (NTRS)

Backes, Paul G.; Hayati, Samad

1990-01-01

A hardware and software environment for shared control of telerobot task execution has been implemented. Modes of task execution range from fully teleoperated to fully autonomous as well as shared where hand controller inputs from the human operator are mixed with autonomous system inputs in real time. The objective of the shared control environment is to aid the telerobot operator during task execution by merging real-time operator control from hand controllers with autonomous control to simplify task execution for the operator. The operator is the principal command source and can assign as much autonomy for a task as desired. The shared control hardware environment consists of two PUMA 560 robots, two 6-axis force reflecting hand controllers, Universal Motor Controllers for each of the robots and hand controllers, a SUN4 computer, and VME chassis containing 68020 processors and input/output boards. The operator interface for shared control, the User Macro Interface (UMI), is a menu driven interface to design a task and assign the levels of teleoperated and autonomous control. The operator also sets up the system monitor which checks safety limits during task execution. Cartesian-space degrees of freedom for teleoperated and/or autonomous control inputs are selected within UMI as well as the weightings for the teleoperation and autonmous inputs. These are then used during task execution to determine the mix of teleoperation and autonomous inputs. Some of the autonomous control primitives available to the user are Joint-Guarded-Move, Cartesian-Guarded-Move, Move-To-Touch, Pin-Insertion/Removal, Door/Crank-Turn, Bolt-Turn, and Slide. The operator can execute a task using pure teleoperation or mix control execution from the autonomous primitives with teleoperated inputs. Presently the shared control environment supports single arm task execution. Work is presently underway to provide the shared control environment for dual arm control. Teleoperation during shared control is only Cartesian space control and no force-reflection is provided. Force-reflecting teleoperation and joint space operator inputs are planned extensions to the environment.

System for loading executable code into volatile memory in a downhole tool

DOEpatents

Hall, David R.; Bartholomew, David B.; Johnson, Monte L.

2007-09-25

A system for loading an executable code into volatile memory in a downhole tool string component comprises a surface control unit comprising executable code. An integrated downhole network comprises data transmission elements in communication with the surface control unit and the volatile memory. The executable code, stored in the surface control unit, is not permanently stored in the downhole tool string component. In a preferred embodiment of the present invention, the downhole tool string component comprises boot memory. In another embodiment, the executable code is an operating system executable code. Preferably, the volatile memory comprises random access memory (RAM). A method for loading executable code to volatile memory in a downhole tool string component comprises sending the code from the surface control unit to a processor in the downhole tool string component over the network. A central processing unit writes the executable code in the volatile memory.

Increased binding of 5-HT1A receptors in a dissociative amnesic patient after the recovery process.

PubMed

Kitamura, Soichiro; Yasuno, Fumihiko; Inoue, Makoto; Kosaka, Jun; Kiuchi, Kuniaki; Matsuoka, Kiwamu; Kishimoto, Toshifumi; Suhara, Tetsuya

2014-10-30

Dissociative amnesia is characterized by an inability to retrieve information already saved in memories. 5-HT has some role in neural regulatory control and may be related to the recovery from dissociative amnesia. To examine the role of 5-HT1A receptors in the recovery from dissociative amnesia, we performed two positron emission tomography (PET) scans on a 30-year-old patient of dissociative amnesia using [(11)C]WAY-100635, the first at amnesic state, and the second at the time he had recovered. Exploratory voxel-based analysis (VBA) was performed using SPM software. 5-HT1A BPND images were compared between the patient at amnesic and recovery states and healthy subjects (14 males, mean age 29.8 ± 6.45) with Jack-knife analysis. 5-HT1A receptor bindings of the patient at the recovery state were significantly higher than those of healthy subjects in the right superior and middle frontal cortex, left inferior frontal and orbitofrontal cortex and bilateral inferior temporal cortex. The increase in BPND values of recovery state was beyond 10% of those of amnesia state in these regions except in the right superior frontal cortex. We considered that neural regulatory control by the increase of 5-HT1A receptors in cortical regions played a role in the recovery from dissociative amnesia. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Language and Memory Improvements following tDCS of Left Lateral Prefrontal Cortex.

PubMed

Hussey, Erika K; Ward, Nathan; Christianson, Kiel; Kramer, Arthur F

2015-01-01

Recent research demonstrates that performance on executive-control measures can be enhanced through brain stimulation of lateral prefrontal regions. Separate psycholinguistic work emphasizes the importance of left lateral prefrontal cortex executive-control resources during sentence processing, especially when readers must override early, incorrect interpretations when faced with temporary ambiguity. Using transcranial direct current stimulation, we tested whether stimulation of left lateral prefrontal cortex had discriminate effects on language and memory conditions that rely on executive-control (versus cases with minimal executive-control demands, even in the face of task difficulty). Participants were randomly assigned to receive Anodal, Cathodal, or Sham stimulation of left lateral prefrontal cortex while they (1) processed ambiguous and unambiguous sentences in a word-by-word self-paced reading task and (2) performed an n-back memory task that, on some trials, contained interference lure items reputed to require executive-control. Across both tasks, we parametrically manipulated executive-control demands and task difficulty. Our results revealed that the Anodal group outperformed the remaining groups on (1) the sentence processing conditions requiring executive-control, and (2) only the most complex n-back conditions, regardless of executive-control demands. Together, these findings add to the mounting evidence for the selective causal role of left lateral prefrontal cortex for executive-control tasks in the language domain. Moreover, we provide the first evidence suggesting that brain stimulation is a promising method to mitigate processing demands encountered during online sentence processing.

Language and Memory Improvements following tDCS of Left Lateral Prefrontal Cortex

PubMed Central

Hussey, Erika K.; Ward, Nathan; Christianson, Kiel; Kramer, Arthur F.

2015-01-01

Recent research demonstrates that performance on executive-control measures can be enhanced through brain stimulation of lateral prefrontal regions. Separate psycholinguistic work emphasizes the importance of left lateral prefrontal cortex executive-control resources during sentence processing, especially when readers must override early, incorrect interpretations when faced with temporary ambiguity. Using transcranial direct current stimulation, we tested whether stimulation of left lateral prefrontal cortex had discriminate effects on language and memory conditions that rely on executive-control (versus cases with minimal executive-control demands, even in the face of task difficulty). Participants were randomly assigned to receive Anodal, Cathodal, or Sham stimulation of left lateral prefrontal cortex while they (1) processed ambiguous and unambiguous sentences in a word-by-word self-paced reading task and (2) performed an n-back memory task that, on some trials, contained interference lure items reputed to require executive-control. Across both tasks, we parametrically manipulated executive-control demands and task difficulty. Our results revealed that the Anodal group outperformed the remaining groups on (1) the sentence processing conditions requiring executive-control, and (2) only the most complex n-back conditions, regardless of executive-control demands. Together, these findings add to the mounting evidence for the selective causal role of left lateral prefrontal cortex for executive-control tasks in the language domain. Moreover, we provide the first evidence suggesting that brain stimulation is a promising method to mitigate processing demands encountered during online sentence processing. PMID:26528814

Relations of Growth in Effortful Control to Family Income, Cumulative Risk, and Adjustment in Preschool-age Children

PubMed Central

Lengua, Liliana J.; Moran, Lyndsey; Zalewski, Maureen; Ruberry, Erika; Kiff, Cara; Thompson, Stephanie

2014-01-01

The study examined growth in effortful control (executive control, delay ability) in relation to income, cumulative risk (aggregate of demographic and psychosocial risk factors), and adjustment in 306 preschool-age children (50% girls, 50% boys) from families representing a range of income (29% at- or near-poverty; 28% lower-income; 25% middle-income; 18% upper-income), with 4 assessments starting at 36–40 mos. Income was directly related to levels of executive control and delay ability. Cumulative risk accounted for the effects of income on delay ability but not executive control. Higher initial executive control and slope of executive control and delay ability predicted academic readiness, whereas levels, but not growth, of executive control and delay ability predicted social competence and adjustment problems. Low income is a marker for lower effortful control, which demonstrates additive or mediating effects in the relation of income to children’s preschool adjustment. PMID:25253079

The cerebellum and visual perceptual learning: evidence from a motion extrapolation task.

PubMed

Deluca, Cristina; Golzar, Ashkan; Santandrea, Elisa; Lo Gerfo, Emanuele; Eštočinová, Jana; Moretto, Giuseppe; Fiaschi, Antonio; Panzeri, Marta; Mariotti, Caterina; Tinazzi, Michele; Chelazzi, Leonardo

2014-09-01

Visual perceptual learning is widely assumed to reflect plastic changes occurring along the cerebro-cortical visual pathways, including at the earliest stages of processing, though increasing evidence indicates that higher-level brain areas are also involved. Here we addressed the possibility that the cerebellum plays an important role in visual perceptual learning. Within the realm of motor control, the cerebellum supports learning of new skills and recalibration of motor commands when movement execution is consistently perturbed (adaptation). Growing evidence indicates that the cerebellum is also involved in cognition and mediates forms of cognitive learning. Therefore, the obvious question arises whether the cerebellum might play a similar role in learning and adaptation within the perceptual domain. We explored a possible deficit in visual perceptual learning (and adaptation) in patients with cerebellar damage using variants of a novel motion extrapolation, psychophysical paradigm. Compared to their age- and gender-matched controls, patients with focal damage to the posterior (but not the anterior) cerebellum showed strongly diminished learning, in terms of both rate and amount of improvement over time. Consistent with a double-dissociation pattern, patients with focal damage to the anterior cerebellum instead showed more severe clinical motor deficits, indicative of a distinct role of the anterior cerebellum in the motor domain. The collected evidence demonstrates that a pure form of slow-incremental visual perceptual learning is crucially dependent on the intact cerebellum, bearing the notion that the human cerebellum acts as a learning device for motor, cognitive and perceptual functions. We interpret the deficit in terms of an inability to fine-tune predictive models of the incoming flow of visual perceptual input over time. Moreover, our results suggest a strong dissociation between the role of different portions of the cerebellum in motor versus non-motor functions, with only the posterior lobe being responsible for learning in the perceptual domain. Copyright © 2014. Published by Elsevier Ltd.

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.

Attention Control, Memory Updating, and Emotion Regulation Temporarily Reduce the Capacity for Executive Control

ERIC Educational Resources Information Center

Schmeichel, Brandon J.

2007-01-01

This research tested the hypothesis that initial efforts at executive control temporarily undermine subsequent efforts at executive control. Four experiments revealed that controlling the focus of visual attention (Experiment 1), inhibiting predominant writing tendencies (Experiment 2), taking a working memory test (Experiment 3), or exaggerating…

Peeling the Onion: Why Centralized Control / Decentralized Execution Works

DTIC Science & Technology

2014-04-01

March–April 2014 Air & Space Power Journal | 24 Feature Peeling the Onion Why Centralized Control / Decentralized Execution Works Lt Col Alan Docauer...DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Peeling the Onion : Why Centralized Control / Decentralized Execution Works 5a...Air & Space Power Journal | 25 Docauer Peeling the Onion Feature What Is Centralized Control / Decentralized Execution? Emerging in the aftermath of

Clustering execution in a processing system to increase power savings

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

Bose, Pradip; Buyuktosunoglu, Alper; Jacobson, Hans M.

Embodiments relate to clustering execution in a processing system. An aspect includes accessing a control flow graph that defines a data dependency and an execution sequence of a plurality of tasks of an application that executes on a plurality of system components. The execution sequence of the tasks in the control flow graph is modified as a clustered control flow graph that clusters active and idle phases of a system component while maintaining the data dependency. The clustered control flow graph is sent to an operating system, where the operating system utilizes the clustered control flow graph for scheduling themore » tasks.« less

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

Gestational and Postnatal Cortisol Profiles of Women With Posttraumatic Stress Disorder and the Dissociative Subtype.

PubMed

Seng, Julia S; Li, Yang; Yang, James J; King, Anthony P; Kane Low, Lisa M; Sperlich, Mickey; Rowe, Heather; Lee, Hyunhwa; Muzik, Maria; Ford, Julian D; Liberzon, Israel

2018-01-01

To test the hypothesis that women with posttraumatic stress disorder (PTSD) have greater salivary cortisol levels across the diurnal curve and throughout gestation, birth, and the postpartum period than women who do not have PTSD. Prospective, longitudinal, biobehavioral cohort study. Prenatal clinics at academic health centers in the Midwest region of the United States. Women expecting their first infants who fit with one of four cohorts: a nonexposed control group, a trauma-exposed control group, a group with PTSD, and a group with the dissociative subtype of PTSD. In the first half of pregnancy, 395 women provided three salivary cortisol specimens on a single day for diurnal data. A subsample of 111 women provided three salivary cortisol specimens per day, 12 times, from early pregnancy to 6 weeks postpartum for longitudinal data. Trauma history, PTSD, and dissociative symptoms were measured via standardized telephone diagnostic interviews with the use of validated epidemiologic measures. Generalized estimating equations were used to determine group differences. Generalized estimating equations showed that women with the dissociative subtype of PTSD had the highest and flattest gestational cortisol level curves. The difference was greatest in early pregnancy, when participants in the dissociative subtype group had cortisol levels 8 times greater in the afternoon and 10 times greater at bedtime than those in the nonexposed control group. Women with the dissociative subtype of PTSD, a complex form associated with a history of childhood maltreatment, may have toxic levels of cortisol that contribute to intergenerational patterns of adverse health outcomes. Copyright © 2018 AWHONN, the Association of Women’s Health, Obstetric and Neonatal Nurses. Published by Elsevier Inc. All rights reserved.

Ethics questions raised by the neuropsychiatric, neuropsychological, educational, developmental, and family characteristics of 18 juveniles awaiting execution in Texas.

PubMed

Lewis, Dorothy Otnow; Yeager, Catherine A; Blake, Pamela; Bard, Barbara; Strenziok, Maren

2004-01-01

Eighteen males condemned to death in Texas for homicides committed prior to the defendants' 18th birthdays received systematic psychiatric, neurologic, neuropsychological, and educational assessments, and all available medical, psychological, educational, social, and family data were reviewed. Six subjects began life with potentially compromised central nervous system (CNS) function (e.g., prematurity, respiratory distress syndrome). All but one experienced serious head traumas in childhood and adolescence. All subjects evaluated neurologically and neuropsychologically had signs of prefrontal cortical dysfunction. Neuropsychological testing was more sensitive to executive dysfunction than neurologic examination. Fifteen (83%) had signs, symptoms, and histories consistent with bipolar spectrum, schizoaffective spectrum, or hypomanic disorders. Two subjects were intellectually limited, and one suffered from parasomnias and dissociation. All but one came from extremely violent and/or abusive families in which mental illness was prevalent in multiple generations. Implications regarding the ethics involved in matters of culpability and mitigation are considered.

Cerebral mechanisms underlying the effects of music during a fatiguing isometric ankle-dorsiflexion task.

PubMed

Bigliassi, Marcelo; Karageorghis, Costas I; Nowicky, Alexander V; Orgs, Guido; Wright, Michael J

2016-10-01

The brain mechanisms by which music-related interventions ameliorate fatigue-related symptoms during the execution of fatiguing motor tasks are hitherto under-researched. The objective of the present study was to investigate the effects of music on brain electrical activity and psychophysiological measures during the execution of an isometric fatiguing ankle-dorsiflexion task performed until the point of volitional exhaustion. Nineteen healthy participants performed two fatigue tests at 40% of maximal voluntary contraction while listening to music or in silence. Electrical activity in the brain was assessed by use of a 64-channel EEG. The results indicated that music downregulated theta waves in the frontal, central, and parietal regions of the brain during exercise. Music also induced a partial attentional switching from associative thoughts to task-unrelated factors (dissociative thoughts) during exercise, which led to improvements in task performance. Moreover, participants experienced a more positive affective state while performing the isometric task under the influence of music. © 2016 Society for Psychophysiological Research.

Electrical Microstimulation of the Pulvinar Biases Saccade Choices and Reaction Times in a Time-Dependent Manner

PubMed Central

2017-01-01

The pulvinar complex is interconnected extensively with brain regions involved in spatial processing and eye movement control. Recent inactivation studies have shown that the dorsal pulvinar (dPul) plays a role in saccade target selection; however, it remains unknown whether it exerts effects on visual processing or at planning/execution stages. We used electrical microstimulation of the dPul while monkeys performed saccade tasks toward instructed and freely chosen targets. Timing of stimulation was varied, starting before, at, or after onset of target(s). Stimulation affected saccade properties and target selection in a time-dependent manner. Stimulation starting before but overlapping with target onset shortened saccadic reaction times (RTs) for ipsiversive (to the stimulation site) target locations, whereas stimulation starting at and after target onset caused systematic delays for both ipsiversive and contraversive locations. Similarly, stimulation starting before the onset of bilateral targets increased ipsiversive target choices, whereas stimulation after target onset increased contraversive choices. Properties of dPul neurons and stimulation effects were consistent with an overall contraversive drive, with varying outcomes contingent upon behavioral demands. RT and choice effects were largely congruent in the visually-guided task, but stimulation during memory-guided saccades, while influencing RTs and errors, did not affect choice behavior. Together, these results show that the dPul plays a primary role in action planning as opposed to visual processing, that it exerts its strongest influence on spatial choices when decision and action are temporally close, and that this choice effect can be dissociated from motor effects on saccade initiation and execution. SIGNIFICANCE STATEMENT Despite a recent surge of interest, the core function of the pulvinar, the largest thalamic complex in primates, remains elusive. This understanding is crucial given the central role of the pulvinar in current theories of integrative brain functions supporting cognition and goal-directed behaviors, but electrophysiological and causal interference studies of dorsal pulvinar (dPul) are rare. Building on our previous studies that pharmacologically suppressed dPul activity for several hours, here we used transient electrical microstimulation at different periods while monkeys performed instructed and choice eye movement tasks, to determine time-specific contributions of pulvinar to saccade generation and decision making. We show that stimulation effects depend on timing and behavioral state and that effects on choices can be dissociated from motor effects. PMID:28119401

The pervasive nature of unconscious social information processing in executive control

PubMed Central

Prabhakaran, Ranjani; Gray, Jeremy R.

2012-01-01

Humans not only have impressive executive abilities, but we are also fundamentally social creatures. In the cognitive neuroscience literature, it has long been assumed that executive control mechanisms, which play a critical role in guiding goal-directed behavior, operate on consciously processed information. Although more recent evidence suggests that unconsciously processed information can also influence executive control, most of this literature has focused on visual masked priming paradigms. However, the social psychological literature has demonstrated that unconscious influences are pervasive, and social information can unintentionally influence a wide variety of behaviors, including some that are likely to require executive abilities. For example, social information can unconsciously influence attention processes, such that simply instructing participants to describe a previous situation in which they had power over someone or someone else had power over them has been shown to unconsciously influence their attentional focus abilities, a key aspect of executive control. In the current review, we consider behavioral and neural findings from a variety of paradigms, including priming of goals and social hierarchical roles, as well as interpersonal interactions, in order to highlight the pervasive nature of social influences on executive control. These findings suggest that social information can play a critical role in executive control, and that this influence often occurs in an unconscious fashion. We conclude by suggesting further avenues of research for investigation of the interplay between social factors and executive control. PMID:22557956

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

Neural dissociation of phonological and visual attention span disorders in developmental dyslexia: FMRI evidence from two case reports.

PubMed

Peyrin, C; Lallier, M; Démonet, J F; Pernet, C; Baciu, M; Le Bas, J F; Valdois, S

2012-03-01

A dissociation between phonological and visual attention (VA) span disorders has been reported in dyslexic children. This study investigates whether this cognitively-based dissociation has a neurobiological counterpart through the investigation of two cases of developmental dyslexia. LL showed a phonological disorder but preserved VA span whereas FG exhibited the reverse pattern. During a phonological rhyme judgement task, LL showed decreased activation of the left inferior frontal gyrus whereas this region was activated at the level of the controls in FG. Conversely, during a visual categorization task, FG demonstrated decreased activation of the parietal lobules whereas these regions were activated in LL as in the controls. These contrasted patterns of brain activation thus mirror the cognitive disorders' dissociation. These findings provide the first evidence for an association between distinct brain mechanisms and distinct cognitive deficits in developmental dyslexia, emphasizing the importance of taking into account the heterogeneity of the reading disorder. Copyright © 2012 Elsevier Inc. All rights reserved.

A prospective investigation of rumination and executive control in predicting overgeneral autobiographical memory in adolescence.

PubMed

Stewart, Tracy M; Hunter, Simon C; Rhodes, Sinéad M

2018-04-01

The CaR-FA-X model (Williams et al., 2007), or capture and rumination (CaR), functional avoidance (FA), and impaired executive control (X), is a model of overgeneral autobiographical memory (OGM). Two mechanisms of the model, rumination and executive control, were examined in isolation and in interaction in order to investigate OGM over time. Across two time points, six months apart, a total of 149 adolescents (13-16 years) completed the minimal-instruction autobiographical memory test, a measure of executive control with both emotional and nonemotional stimuli, and measures of brooding rumination and reflective pondering. The results showed that executive control for emotional information was negatively associated with OGM, but only when reflective pondering levels were high. Therefore, in the context of higher levels of reflective pondering, greater switch costs (i.e., lower executive control) when processing emotional information predicted a decrease in OGM over time.

From intentions to actions: Neural oscillations encode motor processes through phase, amplitude and phase-amplitude coupling.

PubMed

Combrisson, Etienne; Perrone-Bertolotti, Marcela; Soto, Juan Lp; Alamian, Golnoush; Kahane, Philippe; Lachaux, Jean-Philippe; Guillot, Aymeric; Jerbi, Karim

2017-02-15

Goal-directed motor behavior is associated with changes in patterns of rhythmic neuronal activity across widely distributed brain areas. In particular, movement initiation and execution are mediated by patterns of synchronization and desynchronization that occur concurrently across distinct frequency bands and across multiple motor cortical areas. To date, motor-related local oscillatory modulations have been predominantly examined by quantifying increases or suppressions in spectral power. However, beyond signal power, spectral properties such as phase and phase-amplitude coupling (PAC) have also been shown to carry information with regards to the oscillatory dynamics underlying motor processes. Yet, the distinct functional roles of phase, amplitude and PAC across the planning and execution of goal-directed motor behavior remain largely elusive. Here, we address this question with unprecedented resolution thanks to multi-site intracerebral EEG recordings in human subjects while they performed a delayed motor task. To compare the roles of phase, amplitude and PAC, we monitored intracranial brain signals from 748 sites across six medically intractable epilepsy patients at movement execution, and during the delay period where motor intention is present but execution is withheld. In particular, we used a machine-learning framework to identify the key contributions of various neuronal responses. We found a high degree of overlap between brain network patterns observed during planning and those present during execution. Prominent amplitude increases in the delta (2-4Hz) and high gamma (60-200Hz) bands were observed during both planning and execution. In contrast, motor alpha (8-13Hz) and beta (13-30Hz) power were suppressed during execution, but enhanced during the delay period. Interestingly, single-trial classification revealed that low-frequency phase information, rather than spectral power change, was the most discriminant feature in dissociating action from intention. Additionally, despite providing weaker decoding, PAC features led to statistically significant classification of motor states, particularly in anterior cingulate cortex and premotor brain areas. These results advance our understanding of the distinct and partly overlapping involvement of phase, amplitude and the coupling between them, in the neuronal mechanisms underlying motor intentions and executions. Copyright © 2016 Elsevier Inc. All rights reserved.

Attosecond Coherent Control of the Photo-Dissociation of Oxygen Molecules

NASA Astrophysics Data System (ADS)

Sturm, Felix; Ray, Dipanwita; Wright, Travis; Shivaram, Niranjan; Bocharova, Irina; Slaughter, Daniel; Ranitovic, Predrag; Belkacem, Ali; Weber, Thorsten

2016-05-01

Attosecond Coherent Control has emerged in recent years as a technique to manipulate the absorption and ionization in atoms as well as the dissociation of molecules on an attosecond time scale. Single attosecond pulses and attosecond pulse trains (APTs) can coherently excite multiple electronic states. The electronic and nuclear wave packets can then be coupled with a second pulse forming multiple interfering quantum pathways. We have built a high flux extreme ultraviolet (XUV) light source delivering APTs based on HHG that allows to selectively excite neutral and ion states in molecules. Our beamline provides spectral selectivity and attosecond interferometric control of the pulses. In the study presented here, we use APTs, generated by High Harmonic Generation in a high flux extreme ultraviolet light source, to ionize highly excited states of oxygen molecules. We identify the ionization/dissociation pathways revealing vibrational structure with ultra-high resolution ion 3D-momentum imaging spectroscopy. Furthermore, we introduce a delay between IR pulses and XUV/IR pulses to constructively or destructively interfere the ionization and dissociation pathways, thus, enabling the manipulation of both the O2+and the O+ ion yields with attosecond precision. Supported by DOE under Contract No. DE-AC02-05CH11231.

Lexical and semantic processing in the absence of word reading: evidence from neglect dyslexia.

PubMed

Làdavas, E; Umiltà, C; Mapelli, D

1997-08-01

Nine patients with left-sided neglect and nine matched control patients performed three tasks on horizontal (either normal or mirror-reversed) letter strings. The tasks were: reading aloud, making a lexical decision (word vs non-word), and making a semantic decision (living vs non-living item). Relative to controls, neglect patients performed very poorly in the reading task, whereas they performed nearly normally in the lexical and semantic tasks. This was considered to be a dissociation between direct tasks, rather than a dissociation between explicit and implicit knowledge. The explanation offered for the dissociation is in terms of both a dual-route model for reading aloud and a degraded representation of the letter string.

Fact or factitious? A psychobiological study of authentic and simulated dissociative identity states.

PubMed

Reinders, A A T S; Reinders, A A T Simone; Willemsen, Antoon T M; Vos, Herry P J; den Boer, Johan A; Nijenhuis, Ellert R S

2012-01-01

Dissociative identity disorder (DID) is a disputed psychiatric disorder. Research findings and clinical observations suggest that DID involves an authentic mental disorder related to factors such as traumatization and disrupted attachment. A competing view indicates that DID is due to fantasy proneness, suggestibility, suggestion, and role-playing. Here we examine whether dissociative identity state-dependent psychobiological features in DID can be induced in high or low fantasy prone individuals by instructed and motivated role-playing, and suggestion. DID patients, high fantasy prone and low fantasy prone controls were studied in two different types of identity states (neutral and trauma-related) in an autobiographical memory script-driven (neutral or trauma-related) imagery paradigm. The controls were instructed to enact the two DID identity states. Twenty-nine subjects participated in the study: 11 patients with DID, 10 high fantasy prone DID simulating controls, and 8 low fantasy prone DID simulating controls. Autonomic and subjective reactions were obtained. Differences in psychophysiological and neural activation patterns were found between the DID patients and both high and low fantasy prone controls. That is, the identity states in DID were not convincingly enacted by DID simulating controls. Thus, important differences regarding regional cerebral bloodflow and psychophysiological responses for different types of identity states in patients with DID were upheld after controlling for DID simulation. The findings are at odds with the idea that differences among different types of dissociative identity states in DID can be explained by high fantasy proneness, motivated role-enactment, and suggestion. They indicate that DID does not have a sociocultural (e.g., iatrogenic) origin.

Dissociable effects of motivation and expectancy on conflict processing: an fMRI study.

PubMed

Soutschek, Alexander; Stelzel, Christine; Paschke, Lena; Walter, Henrik; Schubert, Torsten

2015-02-01

Previous studies suggest that both motivation and task difficulty expectations activate brain regions associated with cognitive control. However, it remains an open question whether motivational and cognitive determinants of control have similar or dissociable impacts on conflict processing on a neural level. The current study tested the effects of motivation and conflict expectancy on activity in regions related to processing of the target and the distractor information. Participants performed a picture-word interference task in which we manipulated the size of performance-dependent monetary rewards (level of motivation) and the ratio of congruent to incongruent trials within a block (level of conflict expectancy). Our results suggest that motivation improves conflict processing by facilitating task-relevant stimulus processing and task difficulty expectations mainly modulate the processing of distractor information. We conclude that motivation and conflict expectancy engage dissociable control strategies during conflict resolution.

Doing better by getting worse: posthypnotic amnesia improves random number generation.

PubMed

Terhune, Devin Blair; Brugger, Peter

2011-01-01

Although forgetting is often regarded as a deficit that we need to control to optimize cognitive functioning, it can have beneficial effects in a number of contexts. We examined whether disrupting memory for previous numerical responses would attenuate repetition avoidance (the tendency to avoid repeating the same number) during random number generation and thereby improve the randomness of responses. Low suggestible and low dissociative and high dissociative highly suggestible individuals completed a random number generation task in a control condition, following a posthypnotic amnesia suggestion to forget previous numerical responses, and in a second control condition following the cancellation of the suggestion. High dissociative highly suggestible participants displayed a selective increase in repetitions during posthypnotic amnesia, with equivalent repetition frequency to a random system, whereas the other two groups exhibited repetition avoidance across conditions. Our results demonstrate that temporarily disrupting memory for previous numerical responses improves random number generation.

Doing Better by Getting Worse: Posthypnotic Amnesia Improves Random Number Generation

PubMed Central

Terhune, Devin Blair; Brugger, Peter

2011-01-01

Although forgetting is often regarded as a deficit that we need to control to optimize cognitive functioning, it can have beneficial effects in a number of contexts. We examined whether disrupting memory for previous numerical responses would attenuate repetition avoidance (the tendency to avoid repeating the same number) during random number generation and thereby improve the randomness of responses. Low suggestible and low dissociative and high dissociative highly suggestible individuals completed a random number generation task in a control condition, following a posthypnotic amnesia suggestion to forget previous numerical responses, and in a second control condition following the cancellation of the suggestion. High dissociative highly suggestible participants displayed a selective increase in repetitions during posthypnotic amnesia, with equivalent repetition frequency to a random system, whereas the other two groups exhibited repetition avoidance across conditions. Our results demonstrate that temporarily disrupting memory for previous numerical responses improves random number generation. PMID:22195022

Context-dependent switching between proactive and reactive working memory control mechanisms in the right inferior frontal gyrus.

PubMed

Marklund, Petter; Persson, Jonas

2012-11-15

A critical feature of higher cognitive functioning is the capacity to flexibly tailor information processing and behaviors to current situational demands. Recent neurocognitive models have been postulated to account for the dynamic nature of human executive processing by invoking two dissociable cognitive control modes, proactive and reactive control. These may involve partially overlapping, but temporally distinct neural implementation in the prefrontal cortex. Prior brain imaging studies exploring proactive control have mainly used tasks requiring only information about single-items to be retained over unfilled delays. Whether proactive control can also be utilized to facilitate performance in more complex working memory tasks, in which concurrent processing of intervening items and updating is mandatory during contextual cue maintenance remains an open question. To examine this issue and to elucidate the extent to which overlapping neural substrates underlie proactive and reactive control we used fMRI and a modified verbal 3-back paradigm with embedded cues predictive of high-interference trials. This task requires context information to be retained over multiple intervening trials. We found that performance improved with item-specific cues predicting forthcoming lures despite increased working memory load. Temporal dynamics of activation in the right inferior frontal gyrus suggest flexible switching between proactive and reactive control in a context-dependent fashion, with greater sustained responses elicited in the 3-back task involving context maintenance of cue information and greater transient responses elicited in the 3-back task absent of cues. Copyright © 2012 Elsevier Inc. All rights reserved.

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.

Metacognitive Monitoring of Executive Control Engagement during Childhood

ERIC Educational Resources Information Center

Chevalier, Nicolas; Blaye, Agnès

2016-01-01

Emerging executive control supports greater autonomy and increasingly adaptive behavior during childhood. The present study addressed whether children's greater monitoring of how they engage control drives executive control development. Gaze position was recorded while twenty-five 6-year-olds and twenty-eight 10-year-olds performed a self-paced…

From an Executive Network to Executive Control: A Computational Model of the "n"-Back Task

ERIC Educational Resources Information Center

Chatham, Christopher H.; Herd, Seth A.; Brant, Angela M.; Hazy, Thomas E.; Miyake, Akira; O'Reilly, Randy; Friedman, Naomi P.

2011-01-01

A paradigmatic test of executive control, the n-back task, is known to recruit a widely distributed parietal, frontal, and striatal "executive network," and is thought to require an equally wide array of executive functions. The mapping of functions onto substrates in such a complex task presents a significant challenge to any theoretical…

Attentional orienting and executive control are affected by different types of meditation practice.

PubMed

Tsai, Min-Hui; Chou, Wei-Lun

2016-11-01

Several studies have demonstrated the beneficial effects of meditation on attention. The present study investigated the relationship between focused attention (FA) and open monitoring (OM) meditation skills and the various functions of attention. In Experiment 1, we executed the attention network test and compared the performance of experts on dandao meditation with that of ordinary people on this test. The results indicated that the experts specializing in OM meditation demonstrated greater attentional orienting ability compared with those specializing in FA meditation and the control group. In addition, both expert groups registered improvements in their executive control abilities compared with the control group. In Experiment 2, we trained beginners in FA meditation for 3months. The results showed that the experimental group exhibited significantly enhanced executive control ability. We infer that FA meditation skills promote executive control function and OM meditation skills promote both executive control and attentional orienting functions. Copyright © 2016 Elsevier Inc. All rights reserved.

Impact of Elevated Core Body Temperature on Attention Networks.

PubMed

Liu, Kai; Jiang, Qingjun; Li, Li; Li, Bo; Yang, Zhen; Qian, Shaowen; Li, Min; Sun, Gang

2015-12-01

Cognitive function can be impaired after passive heat exposure and with an elevation in core body temperature (Tcore). This study examined the dynamic correlation among passive heat exposure, Tcore, and cognition. We gave the Attention Network Test of alerting, orienting, and executive control to five groups of five young men who were being exposed to a hyperthermic condition (50°C, 40% relative humidity) for 0, 10, 20, 30, or 40 minutes. We used the participants' reaction time, accuracy (correct responses), efficiency (accuracy÷reaction time), and Tcore to estimate optimal curve models for best fit of data. We could not estimate an appropriate curve model for either alerting or orienting with Tcore, change in Tcore, or duration of passive heat exposure. We estimated quadratic models for Tcore and duration (adjusted R=0.752), change in Tcore and duration (0.906), executive control score and duration (0.509), and efficiency of executive control and duration (0.293). We estimated linear models for executive control score and Tcore (0.479), efficiency of executive control and Tcore (0.261), executive control score and change in Tcore (0.279), and efficiency of executive control and change in Tcore (0.262). Different attentional abilities had different sensitivities to thermal stress. Executive control of attention deteriorated linearly with a rise in Tcore within the normal physiologic range, but deteriorated nonlinearly with longer passive heat exposure.

Speed isn’t everything: Complex processing speed measures mask individual differences and developmental changes in executive control

PubMed Central

Cepeda, Nicholas J.; Blackwell, Katharine A.; Munakata, Yuko

2012-01-01

The rate at which people process information appears to influence many aspects of cognition across the lifespan. However, many commonly accepted measures of “processing speed” may require goal maintenance, manipulation of information in working memory, and decision-making, blurring the distinction between processing speed and executive control and resulting in overestimation of processing-speed contributions to cognition. This concern may apply particularly to studies of developmental change, as even seemingly simple processing speed measures may require executive processes to keep children and older adults on task. We report two new studies and a re-analysis of a published study, testing predictions about how different processing speed measures influence conclusions about executive control across the life span. We find that the choice of processing speed measure affects the relationship observed between processing speed and executive control, in a manner that changes with age, and that choice of processing speed measure affects conclusions about development and the relationship among executive control measures. Implications for understanding processing speed, executive control, and their development are discussed. PMID:23432836

Effects of deep brain stimulation of the subthalamic nucleus on inhibitory and executive control over prepotent responses in Parkinson's disease

PubMed Central

Jahanshahi, Marjan

2013-01-01

Inhibition of inappropriate, habitual or prepotent responses is an essential component of executive control and a cornerstone of self-control. Via the hyperdirect pathway, the subthalamic nucleus (STN) receives inputs from frontal areas involved in inhibition and executive control. Evidence is reviewed from our own work and the literature suggesting that in Parkinson's disease (PD), deep brain stimulation (DBS) of the STN has an impact on executive control during attention-demanding tasks or in situations of conflict when habitual or prepotent responses have to be inhibited. These results support a role for the STN in an inter-related set of processes: switching from automatic to controlled processing, inhibitory and executive control, adjusting response thresholds and influencing speed-accuracy trade-offs. Such STN DBS-induced deficits in inhibitory and executive control may contribute to some of the psychiatric problems experienced by a proportion of operated cases after STN DBS surgery in PD. However, as no direct evidence for such a link is currently available, there is a need to provide direct evidence for such a link between STN DBS-induced deficits in inhibitory and executive control and post-surgical psychiatric complications experienced by operated patients. PMID:24399941

Midbrain-Driven Emotion and Reward Processing in Alcoholism

PubMed Central

Müller-Oehring, E M; Jung, Y-C; Sullivan, E V; Hawkes, W C; Pfefferbaum, A; Schulte, T

2013-01-01

Alcohol dependence is associated with impaired control over emotionally motivated actions, possibly associated with abnormalities in the frontoparietal executive control network and midbrain nodes of the reward network associated with automatic attention. To identify differences in the neural response to alcohol-related word stimuli, 26 chronic alcoholics (ALC) and 26 healthy controls (CTL) performed an alcohol-emotion Stroop Match-to-Sample task during functional MR imaging. Stroop contrasts were modeled for color-word incongruency (eg, word RED printed in green) and for alcohol (eg, BEER), positive (eg, HAPPY) and negative (eg, MAD) emotional word content relative to congruent word conditions (eg, word RED printed in red). During color-Stroop processing, ALC and CTL showed similar left dorsolateral prefrontal activation, and CTL, but not ALC, deactivated posterior cingulate cortex/cuneus. An interaction revealed a dissociation between alcohol-word and color-word Stroop processing: ALC activated midbrain and parahippocampal regions more than CTL when processing alcohol-word relative to color-word conditions. In ALC, the midbrain region was also invoked by negative emotional Stroop words thereby showing significant overlap of this midbrain activation for alcohol-related and negative emotional processing. Enhanced midbrain activation to alcohol-related words suggests neuroadaptation of dopaminergic midbrain systems. We speculate that such tuning is normally associated with behavioral conditioning to optimize responses but here contributed to automatic bias to alcohol-related stimuli. PMID:23615665

Midbrain-driven emotion and reward processing in alcoholism.

PubMed

Müller-Oehring, E M; Jung, Y-C; Sullivan, E V; Hawkes, W C; Pfefferbaum, A; Schulte, T

2013-09-01

Alcohol dependence is associated with impaired control over emotionally motivated actions, possibly associated with abnormalities in the frontoparietal executive control network and midbrain nodes of the reward network associated with automatic attention. To identify differences in the neural response to alcohol-related word stimuli, 26 chronic alcoholics (ALC) and 26 healthy controls (CTL) performed an alcohol-emotion Stroop Match-to-Sample task during functional MR imaging. Stroop contrasts were modeled for color-word incongruency (eg, word RED printed in green) and for alcohol (eg, BEER), positive (eg, HAPPY) and negative (eg, MAD) emotional word content relative to congruent word conditions (eg, word RED printed in red). During color-Stroop processing, ALC and CTL showed similar left dorsolateral prefrontal activation, and CTL, but not ALC, deactivated posterior cingulate cortex/cuneus. An interaction revealed a dissociation between alcohol-word and color-word Stroop processing: ALC activated midbrain and parahippocampal regions more than CTL when processing alcohol-word relative to color-word conditions. In ALC, the midbrain region was also invoked by negative emotional Stroop words thereby showing significant overlap of this midbrain activation for alcohol-related and negative emotional processing. Enhanced midbrain activation to alcohol-related words suggests neuroadaptation of dopaminergic midbrain systems. We speculate that such tuning is normally associated with behavioral conditioning to optimize responses but here contributed to automatic bias to alcohol-related stimuli.

Cognitive and anatomic double dissociation in the representation of concrete and abstract words in semantic variant and behavioral variant frontotemporal degeneration.

PubMed

Cousins, Katheryn A Q; York, Collin; Bauer, Laura; Grossman, Murray

2016-04-01

We examine the anatomic basis for abstract and concrete lexical representations in semantic memory by assessing patients with focal neurodegenerative disease. Prior evidence from healthy adult studies suggests that there may be an anatomical dissociation between abstract and concrete representations: abstract words more strongly activate the left inferior frontal gyrus relative to concrete words, while concrete words more strongly activate left anterior-inferior temporal regions. However, this double dissociation has not been directly examined. We test this dissociation in two patient groups with focal cortical atrophy in each of these regions, the behavioral variant of Frontotemporal Degeneration (bvFTD) and the semantic variant of Primary Progressive Aphasia (svPPA). We administered an associativity judgment task for abstract and concrete words, where subjects select which of two words is best associated with a given target word. Both bvFTD and svPPA patients were significantly impaired in their overall performance compared to controls. While controls treated concrete and abstract words equally, we found a category-specific double dissociation in patients' judgments: bvFTD patients showed a concreteness effect (CE), with significantly worse performance for abstract compared to concrete words, while svPPA patients showed reversal of the CE, with significantly worse performance for concrete over abstract words. Regression analyses also revealed an anatomic double dissociation: The CE is associated with inferior frontal atrophy in bvFTD, while reversal of the CE is associated with left anterior-inferior temporal atrophy in svPPA. These results support a cognitive and anatomic model of semantic memory organization where abstract and concrete representations are supported by dissociable neuroanatomic substrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dissociation of metabolic and neurovascular responses to levodopa in the treatment of Parkinson's disease.

PubMed

Hirano, Shigeki; Asanuma, Kotaro; Ma, Yilong; Tang, Chengke; Feigin, Andrew; Dhawan, Vijay; Carbon, Maren; Eidelberg, David

2008-04-16

We compared the metabolic and neurovascular effects of levodopa (LD) therapy for Parkinson's disease (PD). Eleven PD patients were scanned with both [15O]-H2O and [18F]-fluorodeoxyglucose positron emission tomography in the unmedicated state and during intravenous LD infusion. Images were used to quantify LD-mediated changes in the expression of motor- and cognition-related PD covariance patterns in scans of cerebral blood flow (CBF) and cerebral metabolic rate for glucose (CMR). These changes in network activity were compared with those occurring during subthalamic nucleus (STN) deep brain stimulation (DBS), and those observed in a test-retest PD control group. Separate voxel-based searches were conducted to identify individual regions with dissociated treatment-mediated changes in local cerebral blood flow and metabolism. We found a significant dissociation between CBF and CMR in the modulation of the PD motor-related network by LD treatment (p < 0.001). This dissociation was characterized by reductions in network activity in the CMR scans (p < 0.003) occurring concurrently with increases in the CBF scans (p < 0.01). Flow-metabolism dissociation was also evident at the regional level, with LD-mediated reductions in CMR and increases in CBF in the putamen/globus pallidus, dorsal midbrain/pons, STN, and ventral thalamus. CBF responses to LD in the putamen and pons were relatively greater in patients exhibiting drug-induced dyskinesia. In contrast, flow-metabolism dissociation was not present in the STN DBS treatment group or in the PD control group. These findings suggest that flow-metabolism dissociation is a distinctive feature of LD treatment. This phenomenon may be especially pronounced in patients with LD-induced dyskinesia.

Resting-state functional connectivity of the bed nucleus of the stria terminalis in post-traumatic stress disorder and its dissociative subtype.

PubMed

Rabellino, Daniela; Densmore, Maria; Harricharan, Sherain; Jean, Théberge; McKinnon, Margaret C; Lanius, Ruth A

2018-03-01

The bed nucleus of the stria terminals (BNST) is a subcortical structure involved in anticipatory and sustained reactivity to threat and is thus essential to the understanding of anxiety and stress responses. Although chronic stress and anxiety represent a hallmark of post-traumatic stress disorder (PTSD), to date, few studies have examined the functional connectivity of the BNST in PTSD. Here, we used resting state functional Magnetic Resonance Imaging (fMRI) to investigate the functional connectivity of the BNST in PTSD (n = 70), its dissociative subtype (PTSD + DS) (n = 41), and healthy controls (n = 50). In comparison to controls, PTSD showed increased functional connectivity of the BNST with regions of the reward system (ventral and dorsal striatum), possibly underlying stress-induced reward-seeking behaviors in PTSD. By contrast, comparing PTSD + DS to controls, we observed increased functional connectivity of the BNST with the claustrum, a brain region implicated in consciousness and a primary site of kappa-opioid receptors, which are critical to the dynorphin-mediated dysphoric stress response. Moreover, PTSD + DS showed increased functional connectivity of the BNST with brain regions involved in attention and salience detection (anterior insula and caudate nucleus) as compared to PTSD and controls. Finally, BNST functional connectivity positively correlated with default-mode network regions as a function of state identity dissociation, suggesting a role of BNST networks in the disruption of self-relevant processing characterizing the dissociative subtype. These findings represent an important first step in elucidating the role of the BNST in aberrant functional networks underlying PTSD and its dissociative subtype. © 2017 Wiley Periodicals, Inc.

A Hybrid Procedural/Deductive Executive for Autonomous Spacecraft

NASA Technical Reports Server (NTRS)

Pell, Barney; Gamble, Edward B.; Gat, Erann; Kessing, Ron; Kurien, James; Millar, William; Nayak, P. Pandurang; Plaunt, Christian; Williams, Brian C.; Lau, Sonie (Technical Monitor)

1998-01-01

The New Millennium Remote Agent (NMRA) will be the first AI system to control an actual spacecraft. The spacecraft domain places a strong premium on autonomy and requires dynamic recoveries and robust concurrent execution, all in the presence of tight real-time deadlines, changing goals, scarce resource constraints, and a wide variety of possible failures. To achieve this level of execution robustness, we have integrated a procedural executive based on generic procedures with a deductive model-based executive. A procedural executive provides sophisticated control constructs such as loops, parallel activity, locks, and synchronization which are used for robust schedule execution, hierarchical task decomposition, and routine configuration management. A deductive executive provides algorithms for sophisticated state inference and optimal failure recover), planning. The integrated executive enables designers to code knowledge via a combination of procedures and declarative models, yielding a rich modeling capability suitable to the challenges of real spacecraft control. The interface between the two executives ensures both that recovery sequences are smoothly merged into high-level schedule execution and that a high degree of reactivity is retained to effectively handle additional failures during recovery.

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.

Misattributing the Source of Self-Generated Representations Related to Dissociative and Psychotic Symptoms

PubMed Central

Chiu, Chui-De; Tseng, Mei-Chih Meg; Chien, Yi-Ling; Liao, Shih-Cheng; Liu, Chih-Min; Yeh, Yei-Yu; Hwu, Hai-Gwo

2016-01-01

Objective: An intertwined relationship has been found between dissociative and psychotic symptoms, as the two symptom clusters frequently co-occur, suggesting some shared risk factors. Using a source monitoring paradigm, previous studies have shown that patients with schizophrenia made more errors in source monitoring, suggesting that a weakened sense of individuality may be associated with psychotic symptoms. However, no studies have verified a relationship between sense of individuality and dissociation, and it is unclear whether an altered sense of individuality is a shared sociocognitive deficit underlying both dissociation and psychosis. Method: Data from 80 acute psychiatric patients with unspecified mental disorders were analyzed to test the hypothesis that an altered sense of individuality underlies dissociation and psychosis. Behavioral tasks, including tests of intelligence and source monitoring, as well as interview schedules and self-report measures of dissociative and psychotic symptoms, general psychopathology, and trauma history, were administered. Results: Significant correlations of medium effect sizes indicated an association between errors attributing the source of self-generated items and positive psychotic symptoms and the absorption and amnesia measures of dissociation. The associations with dissociative measures remained significant after the effects of intelligence, general psychopathology, and trauma history were excluded. Moreover, the relationships between source misattribution and dissociative measures remained marginally significant and significant after controlling for positive and negative psychotic symptoms, respectively. Limitations: Self-reported measures were collected from a small sample, and most of the participants were receiving medications when tested, which may have influenced their cognitive performance. Conclusions: A tendency to misidentify the source of self-generated items characterized both dissociation and psychosis. An altered sense of individuality embedded in self-referential representations appears to be a common sociocognitive deficit of dissociation and psychosis. PMID:27148147

(abstract) An Ada Language Modular Telerobot Task Execution System

NASA Technical Reports Server (NTRS)

Backes, Paul; Long, Mark; Steele, Robert

1993-01-01

A telerobotic task execution system is described which has been developed for space flight applications. The Modular Telerobot Task Execution System (MOTES) provides the remote site task execution capability in a local-remote telerobotic system. The system provides supervised autonomous control, shared control, and teleoperation for a redundant manipulator. The system is capable of nominal task execution as well as monitoring and reflex motion.

Executive Control in a Modified Antisaccade Task: Effects of Aging and Bilingualism

ERIC Educational Resources Information Center

Bialystok, Ellen; Craik, Fergus I. M.; Ryan, Jennifer

2006-01-01

Two studies are reported that assess differences associated with aging and bilingualism in an executive control task. Previous work has suggested that bilinguals have an advantage over monolinguals in nonlinguistic tasks involving executive control; the major purpose of the present article is to ascertain which aspects of control are sensitive…

Individual differences in executive control relate to metaphor processing: an eye movement study of sentence reading

PubMed Central

Columbus, Georgie; Sheikh, Naveed A.; Côté-Lecaldare, Marilena; Häuser, Katja; Baum, Shari R.; Titone, Debra

2015-01-01

Metaphors are common elements of language that allow us to creatively stretch the limits of word meaning. However, metaphors vary in their degree of novelty, which determines whether people must create new meanings on-line or retrieve previously known metaphorical meanings from memory. Such variations affect the degree to which general cognitive capacities such as executive control are required for successful comprehension. We investigated whether individual differences in executive control relate to metaphor processing using eye movement measures of reading. Thirty-nine participants read sentences including metaphors or idioms, another form of figurative language that is more likely to rely on meaning retrieval. They also completed the AX-CPT, a domain-general executive control task. In Experiment 1, we examined sentences containing metaphorical or literal uses of verbs, presented with or without prior context. In Experiment 2, we examined sentences containing idioms or literal phrases for the same participants to determine whether the link to executive control was qualitatively similar or different to Experiment 1. When metaphors were low familiar, all people read verbs used as metaphors more slowly than verbs used literally (this difference was smaller for high familiar metaphors). Executive control capacity modulated this pattern in that high executive control readers spent more time reading verbs when a prior context forced a particular interpretation (metaphorical or literal), and they had faster total metaphor reading times when there was a prior context. Interestingly, executive control did not relate to idiom processing for the same readers. Here, all readers had faster total reading times for high familiar idioms than literal phrases. Thus, executive control relates to metaphor but not idiom processing for these readers, and for the particular metaphor and idiom reading manipulations presented. PMID:25628557

Towards a better understanding of the relationship between executive control and theory of mind: an intra-cultural comparison of three diverse samples.

PubMed

Shahaeian, Ameneh; Henry, Julie D; Razmjoee, Maryam; Teymoori, Ali; Wang, Cen

2015-09-01

Previous research has consistently indicated that theory of mind (ToM) is associated with executive control in the preschool years. However, interpretation of this literature is limited by the fact that most studies have focused exclusively on urbanized Western cultural samples. Consequently, it is not clear whether the association between ToM and executive control reflects the specific features of this particular cohort or instead reflects a universal pattern. The present study provides the first empirical assessment of these two constructs in three diverse groups of Iranian children. Participants were 142 preschoolers (4-5 years old) from high-socioeconomic status (SES) urban (n = 33), low-SES urban (n = 37) and rural villages (n = 77). The results show that there is a robust association between ToM and executive control in all three groups, and that executive control contributes significant unique variance to ToM understanding, even after controlling for a range of variables that have been proposed as potential confounders of this relationship. However, although the three groups were equated in ToM, significant differences in executive control were evident. Moreover, cluster analysis identified three distinct clusters that were relatively homogeneous with respect to executive control and SES. One of these clusters was characterized by both low SES and low executive functioning, and showed little evidence of ToM understanding. Taken together, these findings provide possibly the clearest evidence to date that the association between ToM and executive control is not dependent on children's previous experiences on the tasks, or their family and cultural background. © 2014 John Wiley & Sons Ltd.

Individual differences in executive control relate to metaphor processing: an eye movement study of sentence reading.

PubMed

Columbus, Georgie; Sheikh, Naveed A; Côté-Lecaldare, Marilena; Häuser, Katja; Baum, Shari R; Titone, Debra

2014-01-01

Metaphors are common elements of language that allow us to creatively stretch the limits of word meaning. However, metaphors vary in their degree of novelty, which determines whether people must create new meanings on-line or retrieve previously known metaphorical meanings from memory. Such variations affect the degree to which general cognitive capacities such as executive control are required for successful comprehension. We investigated whether individual differences in executive control relate to metaphor processing using eye movement measures of reading. Thirty-nine participants read sentences including metaphors or idioms, another form of figurative language that is more likely to rely on meaning retrieval. They also completed the AX-CPT, a domain-general executive control task. In Experiment 1, we examined sentences containing metaphorical or literal uses of verbs, presented with or without prior context. In Experiment 2, we examined sentences containing idioms or literal phrases for the same participants to determine whether the link to executive control was qualitatively similar or different to Experiment 1. When metaphors were low familiar, all people read verbs used as metaphors more slowly than verbs used literally (this difference was smaller for high familiar metaphors). Executive control capacity modulated this pattern in that high executive control readers spent more time reading verbs when a prior context forced a particular interpretation (metaphorical or literal), and they had faster total metaphor reading times when there was a prior context. Interestingly, executive control did not relate to idiom processing for the same readers. Here, all readers had faster total reading times for high familiar idioms than literal phrases. Thus, executive control relates to metaphor but not idiom processing for these readers, and for the particular metaphor and idiom reading manipulations presented.

Attention processes in chronic fatigue syndrome: attentional bias for health-related threat and the role of attentional control.

PubMed

Hou, Ruihua; Moss-Morris, Rona; Risdale, Anna; Lynch, Jeannette; Jeevaratnam, Preshan; Bradley, Brendan P; Mogg, Karin

2014-01-01

Cognitive behavioural models of chronic fatigue syndrome (CFS) propose that attention processes, specifically, enhanced selective attention to health-threat related cues, may play an important role in symptom maintenance. The current study investigated attentional bias towards health-threat stimuli in CFS. It also examined whether individuals with CFS have impaired executive attention, and whether this was related to attentional bias. 27 participants with CFS and 35 healthy controls completed a Visual Probe Task measuring attentional bias, and an Attention Network Test measuring executive attention, alerting and orienting. Participants also completed self-report measures of CFS and mood symptoms. Compared to the control group, the CFS group showed greater attentional bias for health-threat words than pictures; and the CFS group was significantly impaired in executive attention. Furthermore, CFS individuals with poor executive attention showed greater attentional bias to health-threat related words, compared not only to controls but also to CFS individuals with good executive attention. Thus, this study revealed a significant relationship between attentional bias and executive attention in CFS: attentional bias to threat was primarily evident in those with impaired executive attention control. Taking account of individual differences in executive attention control in current intervention models may be beneficial for CFS. Copyright © 2013 Elsevier Ltd. All rights reserved.

The contributions of cerebro-cerebellar circuitry to executive verbal working memory.

PubMed

Marvel, Cherie L; Desmond, John E

2010-01-01

Contributions of cerebro-cerebellar function to executive verbal working memory were examined using event-related functional magnetic resonance imaging (fMRI) while 16 subjects completed two versions of the Sternberg task. In both versions subjects were presented with two or six target letters during the encoding phase, which were held in memory during the maintenance phase. A single probe letter was presented during the retrieval phase. In the "match condition", subjects decided whether the probe matched the target letters. In the "executive condition", subjects created a new probe by counting two alphabetical letters forward (e.g., f-->h) and decided whether the new probe matched the target letters. Neural activity during the match and executive conditions was compared during each phase of the task. There were four main findings. First, cerebro-cerebellar activity increased as a function of executive load. Second, the dorsal cerebellar dentate co-activated with the supplementary motor area (SMA) during encoding. This likely represented the formation of an articulatory (motor) trajectory. Third, the ventral cerebellar dentate co-activated with anterior prefrontal regions Brodmann Area (BA) 9/46 and the pre-SMA during retrieval. This likely represented the manipulation of information and formation of a response. A functional dissociation between the dorsal "motor" dentate and "cognitive" ventral dentate agrees with neuroanatomical tract tracing studies that have demonstrated separate neural pathways involving each region of the dentate: the dorsal dentate projects to frontal motor areas (including the SMA), and the ventral dentate projects to frontal cognitive areas (including BA 9/46 and the pre-SMA). Finally, activity during the maintenance phase in BA 9, anterior insula, pre-SMA and ventral dentate predicted subsequent accuracy of response to the probe during the retrieval phase. This finding underscored the significant contribution of the pre-SMA/ventral dentate pathway--observed several seconds prior to any motor response to the probe--to executive verbal working memory. Copyright (c) 2009 Elsevier Srl. All rights reserved.

The Contributions of Cerebro-Cerebellar Circuitry to Executive Verbal Working Memory

PubMed Central

Marvel, Cherie L.; Desmond, John E.

2009-01-01

Contributions of cerebro-cerebellar function to executive verbal working memory were examined using event-related functional magnetic resonance imaging (fMRI) while 16 subjects completed two versions of the Sternberg task. In both versions subjects were presented with two or six target letters during the encoding phase, which were held in memory during the maintenance phase. A single probe letter was presented during the retrieval phase. In the “match condition”, subjects decided whether the probe matched the target letters. In the “executive condition”, subjects created a new probe by counting two alphabetical letters forward (e.g., f → h) and decided whether the new probe matched the target letters. Neural activity during the match and executive conditions was compared during each phase of the task. There were four main findings. First, cerebro-cerebellar activity increased as a function of executive load. Second, the dorsal cerebellar dentate co-activated with the supplementary motor area (SMA) during encoding. This likely represented the formation of an articulatory (motor) trajectory. Third, the ventral cerebellar dentate co-activated with anterior prefrontal regions BA 9/46 and the pre-SMA during retrieval. This likely represented the manipulation of information and formation of a response. A functional dissociation between the dorsal “motor” dentate and “cognitive” ventral dentate agrees with neuroanatomical tract tracing studies that have demonstrated separate neural pathways involving each region of the dentate: the dorsal dentate projects to frontal motor areas (including the SMA), and the ventral dentate projects to frontal cognitive areas (including BA 9/46 and the pre-SMA). Finally, activity during the maintenance phase in BA 9, anterior insula, pre-SMA and ventral dentate predicted subsequent accuracy of response to the probe during the retrieval phase. This finding underscored the significant contribution of the pre-SMA/ventral dentate pathway – observed several seconds prior to any motor response to the probe -- to executive verbal working memory. PMID:19811779

Shame, Dissociation, and Complex PTSD Symptoms in Traumatized Psychiatric and Control Groups: Direct and Indirect Associations With Relationship Distress.

PubMed

Dorahy, Martin J; Corry, Mary; Black, Rebecca; Matheson, Laura; Coles, Holly; Curran, David; Seager, Lenaire; Middleton, Warwick; Dyer, Kevin F W

2017-04-01

Elevated shame and dissociation are common in dissociative identity disorder (DID) and chronic posttraumatic stress disorder (PTSD) and are part of the constellation of symptoms defined as complex PTSD. Previous work examined the relationship between shame, dissociation, and complex PTSD and whether they are associated with intimate relationship anxiety, relationship depression, and fear of relationships. This study investigated these variables in traumatized clinical samples and a nonclinical community group. Participants were drawn from the DID (n = 20), conflict-related chronic PTSD (n = 65), and nonclinical (n = 125) populations and completed questionnaires assessing the variables of interest. A model examining the direct impact of shame and dissociation on relationship functioning, and their indirect effect via complex PTSD symptoms, was tested through path analysis. The DID sample reported significantly higher dissociation, shame, complex PTSD symptom severity, relationship anxiety, relationship depression, and fear of relationships than the other two samples. Support was found for the proposed model, with shame directly affecting relationship anxiety and fear of relationships, and pathological dissociation directly affecting relationship anxiety and relationship depression. The indirect effect of shame and dissociation via complex PTSD symptom severity was evident on all relationship variables. Shame and pathological dissociation are important for not only the effect they have on the development of other complex PTSD symptoms, but also their direct and indirect effects on distress associated with relationships. © 2016 Wiley Periodicals, Inc.

Abolishment of Spontaneous Flight Turns in Visually Responsive Drosophila.

PubMed

Ferris, Bennett Drew; Green, Jonathan; Maimon, Gaby

2018-01-22

Animals react rapidly to external stimuli, such as an approaching predator, but in other circumstances, they seem to act spontaneously, without any obvious external trigger. How do the neural processes mediating the execution of reflexive and spontaneous actions differ? We studied this question in tethered, flying Drosophila. We found that silencing a large but genetically defined set of non-motor neurons virtually eliminates spontaneous flight turns while preserving the tethered flies' ability to perform two types of visually evoked turns, demonstrating that, at least in flies, these two modes of action are almost completely dissociable. Copyright © 2017 Elsevier Ltd. All rights reserved.

Imbalanced functional link between executive control network and reward network explain the online-game seeking behaviors in Internet gaming disorder.

PubMed

Dong, Guangheng; Lin, Xiao; Hu, Yanbo; Xie, Chunming; Du, Xiaoxia

2015-03-17

Literatures have shown that Internet gaming disorder (IGD) subjects show impaired executive control and enhanced reward sensitivities than healthy controls. However, how these two networks jointly affect the valuation process and drive IGD subjects' online-game-seeking behaviors remains unknown. Thirty-five IGD and 36 healthy controls underwent a resting-states scan in the MRI scanner. Functional connectivity (FC) was examined within control and reward network seeds regions, respectively. Nucleus accumbens (NAcc) was selected as the node to find the interactions between these two networks. IGD subjects show decreased FC in the executive control network and increased FC in the reward network when comparing with the healthy controls. When examining the correlations between the NAcc and the executive control/reward networks, the link between the NAcc - executive control network is negatively related with the link between NAcc - reward network. The changes (decrease/increase) in IGD subjects' brain synchrony in control/reward networks suggest the inefficient/overly processing within neural circuitry underlying these processes. The inverse proportion between control network and reward network in IGD suggest that impairments in executive control lead to inefficient inhibition of enhanced cravings to excessive online game playing. This might shed light on the mechanistic understanding of IGD.

A right hemisphere safety backup at work: hypotheses for deep hypnosis, post-traumatic stress disorder, and dissociation identity disorder.

PubMed

Burnand, Gordon

2013-09-01

Problem theory points to an a priori relation between six key problems of living, to which people have adapted through evolution. Children are guided through the problems one by one, learning to switch between them automatically and unawares. The first problem of raising hope of certainty (about the environment), is dealt with in the right hemisphere (RH). The second of raising hope of freedom (or power to control), is dealt with in the left hemisphere (LH). Here adventurousness and ignoring the goodness of outcomes potentially create recklessness. When uncertainty rises the RH activates a backup with an override that substitutes immobility, takes over sensory inputs, but allows obedience to parental commands, and a cut-out that stops new work on the freedom problem. Support for the use of the backup by infants is found in the immobility that precedes the crying in strange conditions, and in childhood EEGs. The hypothesis that the backup is active in deep hypnosis imposes accord on findings that appear contradictory. For example it accounts for why observations during deep hypnosis emphasize the activity of the RH, but observations of responsive people not under hypnosis emphasize the activity of the LH. The hypothesis that the backup is active in post-traumatic stress disorder (PTSD) is supported by (a) fMRI observations that could reflect the cut-out, in that part of the precuneus has low metabolism, (b) the recall of motionlessness at the time of the trauma, (c) an argument that playing dead as a defence against predators is illogical, (d) the ease of hypnosis. With dissociative identity disorder (DID), the theory is consistent with up to six alters that have executive control and one trauma identity state where childhood traumas are re-experienced. Support for the cut-out affecting the trauma identity state comes from suppression of part of the precuneus and other parts of the parietal lobe when the trauma identity state is salient and a general script about a trauma is listened to. Support also comes from the ease of hypnosis. The cut-out acts independently of the override. It is linked to low metabolism at the same point in the left precuneus by evidence from all three conditions, hypnosis, PTSD and DID. The concept of dissociation is not required with any of the hypotheses. Copyright © 2013 Elsevier Ltd. All rights reserved.

77 FR 58585 - Appointment of Members of Senior Executive Services Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-21

... OFFICE OF NATIONAL DRUG CONTROL POLICY Appointment of Members of Senior Executive Services Performance Review Board AGENCY: Office of National Drug Control Policy [ONDCP]. ACTION: Notice of... Counsel (202) 395-6709, Office of National Drug Control Policy, Executive Office of the President...

Profile of executive deficits in cocaine and heroin polysubstance users: common and differential effects on separate executive components.

PubMed

Verdejo-García, Antonio; Pérez-García, Miguel

2007-03-01

Structure of executive function was examined and we contrasted performance of substance dependent individuals (polysubstance users) and control participants on neuropsychological measures assessing the different executive components obtained. Additionally, we contrasted performance of polysubstance users with preference for cocaine vs heroin and controls to explore possible differential effects of the main substance abused on executive impairment. Two groups of participants were recruited: abstinent polysubstance users and controls. Polysubstance users were further subdivided based on their drug of choice (cocaine vs heroin). We administered to all participants a comprehensive protocol of executive measures, including tests of fluency, working memory, reasoning, inhibitory control, flexibility, and decision making. Consistent with previous models, the principal component analysis showed that executive functions are organized into four separate components, three of them previously described: updating, inhibition, and shifting; and a fourth component of decision making. Abstinent polysubstance users had clinically significant impairments on measures assessing these four executive components (with effect sizes ranging from 0.5 to 2.2). Cocaine polysubstance users had more severe impairments than heroin users and controls on measures of inhibition (Stroop) and shifting (go/no go and category test). Greater severity of drug use predicted poorer performance on updating measures. Executive functions can be fractionated into four relatively independent components. Chronic drug use is associated with widespread impairment of these four executive components, with cocaine use inducing more severe deficits on inhibition and shifting. These findings show both common and differential effects of two widely used drugs on different executive components.

Dissociative symptoms and amnesia in Dutch concentration camp survivors.

PubMed

Merckelbach, Harald; Dekkers, Theo; Wessel, Ineke; Roefs, Anne

2003-01-01

We examined to what extent dissociative phenomena in concentration camp survivors are related to post-traumatic stress symptoms. Self-reports of amnesia for traumatic war events and other dissociative experiences were studied in a sample of 31 Dutch survivors of World War II (WWII) Japanese concentration camps. Seventeen survivors treated for war-related psychiatric symptoms were compared to 14 concentration camp survivors who had no psychiatric diagnosis. Although survivors who received treatment scored significantly higher on the Impact of Event Scale and the Post-Traumatic Symptom Scale than control survivors, the two groups did not differ in terms of accessibility of war memories or dissociative experiences. Levels of post-traumatic stress symptoms were not significantly correlated with dissociative experiences. In both groups, reports of psychogenic amnesia for traumatic events were rare. Our results support previous studies demonstrating that post-traumatic stress symptoms are not necessarily accompanied by dissociative experiences. They also contradict the suggestion that amnesia is a common phenomenon in people who have been exposed to war atrocities. Copyright 2003, Elsevier Science (USA). All rights reserved.

Fact or Factitious? A Psychobiological Study of Authentic and Simulated Dissociative Identity States

PubMed Central

Simone Reinders, A. A. T.; Willemsen, Antoon T. M.; Vos, Herry P. J.; den Boer, Johan A.; Nijenhuis, Ellert R. S.

2012-01-01

Background Dissociative identity disorder (DID) is a disputed psychiatric disorder. Research findings and clinical observations suggest that DID involves an authentic mental disorder related to factors such as traumatization and disrupted attachment. A competing view indicates that DID is due to fantasy proneness, suggestibility, suggestion, and role-playing. Here we examine whether dissociative identity state-dependent psychobiological features in DID can be induced in high or low fantasy prone individuals by instructed and motivated role-playing, and suggestion. Methodology/Principal Findings DID patients, high fantasy prone and low fantasy prone controls were studied in two different types of identity states (neutral and trauma-related) in an autobiographical memory script-driven (neutral or trauma-related) imagery paradigm. The controls were instructed to enact the two DID identity states. Twenty-nine subjects participated in the study: 11 patients with DID, 10 high fantasy prone DID simulating controls, and 8 low fantasy prone DID simulating controls. Autonomic and subjective reactions were obtained. Differences in psychophysiological and neural activation patterns were found between the DID patients and both high and low fantasy prone controls. That is, the identity states in DID were not convincingly enacted by DID simulating controls. Thus, important differences regarding regional cerebral bloodflow and psychophysiological responses for different types of identity states in patients with DID were upheld after controlling for DID simulation. Conclusions/Significance The findings are at odds with the idea that differences among different types of dissociative identity states in DID can be explained by high fantasy proneness, motivated role-enactment, and suggestion. They indicate that DID does not have a sociocultural (e.g., iatrogenic) origin. PMID:22768068

High frequency fo X-Y chromosome dissociation in primary spermatocytes of F1 hybrids between Japanese wild mice (Mus musculus molossinus) and inbred laboratory mice.

PubMed

Imai, H T; Matsuda, Y; Shiroishi, T; Moriwaki, K

1981-01-01

In the hybrids between Japanese wild mice (Mus musculus molossinus) and inbred laboratory mice (BALB/c and B10.BR, which were probably derived from M. m. domesticus), the X and Y chromosomes dissociated precociously at the first meiotic metaphase in some 70% of spermatocytes; that percentage was only 8.9% in inbred laboratory mice and 21.1% in wild mice. X-Y dissociation began at least at early diakinesis and continued during metaphase I (MI). Some autosomes of the hybrid (10.1%) and BALB/c (10.6%) mice also dissociated precociously, but there was no distinctive correlation between X-Y and autosomal dissociation. In B10 or B6 congenic lines with a Y chromosome from wild M. m. molossinus, there was an apparent tendency for the percentage of precocious X-Y dissociation to decrease with an increasing number of back cross generations. Based on these observations we concluded that: 1. the X-Y dissociation found is genetically controlled, perhaps by multiple genes; 2. these genes are located on autosomes and are active only when they are heterozygous; 3. the frequent dissociation of the sex chromosomes neither affects male fertility nor induces non-disjunction of the X and Y chromosomes, though it significantly reduces testes weight.

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

Level of Construal, Mind Wandering, and Repetitive Thought

PubMed Central

Watkins, Edward R.

2010-01-01

In this reply to the comment of McVay and Kane (2010)Watkins’s (2008) elaborated control theory informs their perspective on the role of executive control in mind wandering. I argue that although in a number of places the elaborated control theory is consistent with the perspective of McVay and Kane that mind wandering represents a failure of executive control, their account makes a number of claims that are not articulated in the elaborated control theory—most notably, the hypothesis that level of construal moderates entry of thoughts into awareness. Moreover, the relevant literature suggests that the relationship between level of construal and executive control may be more complex, and may be determined by multiple factors beyond those proposed in this executive-control failure account of mind wandering. Finally, the implications of this model of mind wandering for understanding repetitive thought in general are considered, and it is proposed that examining level of executive control as a further moderating variable within elaborated control theory may be of value.

Real World Executive Control Impairments in Preschoolers with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Smithson, Pontea Etemad; Kenworthy, Lauren; Wills, Meagan C.; Jarrett, Marian; Atmore, Kathleen; Yerys, Benjamin E.

2013-01-01

This study examined executive control (EC) in preschoolers with and without autism spectrum disorders (ASD) using the Behavior Rating Inventory of Executive Functions-Preschool Version (BRIEF-P). ASD participants were a clinically referred sample of preschoolers; the typically developing control group was selected from the BRIEF-P standardization…

Pulsed IR Heating Studies of Single-Molecule DNA Duplex Dissociation Kinetics and Thermodynamics

PubMed Central

Holmstrom, Erik D.; Dupuis, Nicholas F.; Nesbitt, David J.

2014-01-01

Single-molecule fluorescence spectroscopy is a powerful technique that makes it possible to observe the conformational dynamics associated with biomolecular processes. The addition of precise temperature control to these experiments can yield valuable thermodynamic information about equilibrium and kinetic rate constants. To accomplish this, we have developed a microscopy technique based on infrared laser overtone/combination band absorption to heat small (≈10−11 liter) volumes of water. Detailed experimental characterization of this technique reveals three major advantages over conventional stage heating methods: 1), a larger range of steady-state temperatures (20–100°C); 2), substantially superior spatial (≤20 μm) control; and 3), substantially superior temporal (≈1 ms) control. The flexibility and breadth of this spatial and temporally resolved laser-heating approach is demonstrated in single-molecule fluorescence assays designed to probe the dissociation of a 21 bp DNA duplex. These studies are used to support a kinetic model based on nucleic acid end fraying that describes dissociation for both short (<10 bp) and long (>10 bp) DNA duplexes. These measurements have been extended to explore temperature-dependent kinetics for the 21 bp construct, which permit determination of single-molecule activation enthalpies and entropies for DNA duplex dissociation. PMID:24411254

Dissociable Frontostriatal White Matter Connectivity Underlies Reward and Motor Impulsivity

PubMed Central

Hampton, William H.; Alm, Kylie H.; Venkatraman, Vinod; Nugiel, Tehila; Olson, Ingrid R.

2017-01-01

Dysfunction of cognitive control often leads to impulsive decision-making in clinical and healthy populations. Some research suggests that a generalized cognitive control mechanism underlies the ability to modulate various types of impulsive behavior, while other evidence suggests different forms of impulsivity are dissociable, and rely on distinct neural circuitry. Past research consistently implicates several brain regions, such as the striatum and portions of the prefrontal cortex, in impulsive behavior. However the ventral and dorsal striatum are distinct in regards to function and connectivity. Nascent evidence points to the importance of frontostriatal white matter connectivity in impulsivity, yet it remains unclear whether particular tracts relate to different control behaviors. Here we used probabilistic tractography of diffusion imaging data to relate ventral and dorsal frontostriatal connectivity to reward and motor impulsivity measures. We found a double dissociation such that individual differences in white matter connectivity between the ventral striatum and the ventromedial prefrontal cortex and dorsolateral prefrontal cortex was associated with reward impulsivity, as measured by delay discounting, whereas connectivity between dorsal striatum and supplementary motor area was associated with motor impulsivity, but not vice versa. Our findings suggest that (a) structural connectivity can is associated with a large amount of behavioral variation; (b) different types of impulsivity are driven by dissociable frontostriatal neural circuitry. PMID:28189592

Age-Related Differences in the Reliance on Executive Control in Working Memory: Role of Task Demand

PubMed Central

Isingrini, Michel; Angel, Lucie; Fay, Séverine; Taconnat, Laurence; Lemaire, Patrick; Bouazzaoui, Badiâa

2015-01-01

We examined the hypothesis that age-related differences in the reliance on executive control may be better explained by variations of task demand than by a mechanism specifically linked to aging. To this end, we compared the relationship between the performance of young and older adults on two executive functioning tests and an updating working-memory task with different load levels. The results revealed a significant interaction between age, task demand, and individual executive capacities, indicating that executive resources were only involved at lower loads in older adults, and only at higher loads in young adults. Overall, the results are not consistent with the proposition that cognition places greater demand on executive control in older adults. However, they support the view that how much young and older adults rely on executive control to accomplish cognitive tasks depends on task demand. Finally, interestingly these results are consistent with the CRUNCH model accounting for age-related differences in brain activations. PMID:26700019

Age-Related Differences in the Reliance on Executive Control in Working Memory: Role of Task Demand.

PubMed

Isingrini, Michel; Angel, Lucie; Fay, Séverine; Taconnat, Laurence; Lemaire, Patrick; Bouazzaoui, Badiâa

2015-01-01

We examined the hypothesis that age-related differences in the reliance on executive control may be better explained by variations of task demand than by a mechanism specifically linked to aging. To this end, we compared the relationship between the performance of young and older adults on two executive functioning tests and an updating working-memory task with different load levels. The results revealed a significant interaction between age, task demand, and individual executive capacities, indicating that executive resources were only involved at lower loads in older adults, and only at higher loads in young adults. Overall, the results are not consistent with the proposition that cognition places greater demand on executive control in older adults. However, they support the view that how much young and older adults rely on executive control to accomplish cognitive tasks depends on task demand. Finally, interestingly these results are consistent with the CRUNCH model accounting for age-related differences in brain activations.

Environmental adversities and psychotic symptoms: The impact of timing of trauma, abuse, and neglect.

PubMed

Schalinski, Inga; Breinlinger, Susanne; Hirt, Vanessa; Teicher, Martin H; Odenwald, Michael; Rockstroh, Brigitte

2017-11-13

Trauma and adverse childhood experiences (ACE) occur more often in mental illness, including psychosis, than in the general population. Individuals with psychosis (cases) report a higher number and severity (dose) of adversities than healthy controls. While a dose-dependent increase of adversities has been related to more severe psychopathology, the role of type and timing is still insufficiently understood on the exacerbation of positive and negative psychotic symptoms. Moreover, dissociative symptoms were examined as potential mediator between adversities and severity of psychotic symptoms. Exposure to adversities were assessed by interviews in n=180 cases and n=70 controls. In cases, symptom severities were obtained for psychotic symptoms and dissociation. Conditioned random forest regression determined the importance of type and timing of ACE for positive and negative symptom severity, and mediator analyses evaluated the role of dissociative symptoms in the relationship between adversities and psychotic symptoms. Cases experienced substantially more abuse and neglect than controls. Adversities were related in a dose-dependent manner to psychotic disorder. An array of adversities was associated with more severe positive symptoms, while the conditioned random forest regression depicted neglect at age 10 as the most important predictor. Dissociative symptoms mediated the small relation of trauma load in childhood and positive symptoms. The role of trauma and ACE on psychotic symptoms can be specified by neglect during frontocortical development in the exacerbation of positive symptoms. The mediating role of dissociation is restricted to the relation of childhood trauma and positive symptoms. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

Prediction and Uncertainty in Human Pavlovian to Instrumental Transfer

ERIC Educational Resources Information Center

Trick, Leanne; Hogarth, Lee; Duka, Theodora

2011-01-01

Attentional capture and behavioral control by conditioned stimuli have been dissociated in animals. The current study assessed this dissociation in humans. Participants were trained on a Pavlovian schedule in which 3 visual stimuli, A, B, and C, predicted the occurrence of an aversive noise with 90%, 50%, or 10% probability, respectively.…

Temperament, Executive Control, and ADHD across Early Development

PubMed Central

Rabinovitz, Beth B.; O’Neill, Sarah; Rajendran, Khushmand; Halperin, Jeffrey M.

2015-01-01

Research examining factors linking early temperament and later ADHD is limited by cross-sectional approaches and having the same informant rate both temperament and psychopathology. We used multi-informant/multi-method longitudinal data to test the hypothesis that negative emotionality during preschool is positively associated with ADHD symptom severity in middle childhood, but developing executive control mediates this relation. Children (N=161) with and without ADHD were evaluated three times: Parent and teacher temperament ratings and NEPSY Visual Attention at ages 3–4 years; WISC-IV Working Memory Index and NEPSY Response Set at age 6 years; and ADHD symptoms using the Kiddie-SADS at age 7 years. Parent and teacher ratings of preschoolers’ temperament were combined to form an Anger/Frustration composite. Similarly, an Executive Functioning composite was derived from age 6 measures. Bootstrapping was used to determine whether age 6 Executive Functioning mediated the relation between early Anger/Frustration and later ADHD symptom severity, while controlling for early executive functioning. Preschoolers’ Anger/Frustration was significantly associated with later ADHD symptoms, with this relation partially mediated by age 6 Executive Functioning. Developing executive control mediates the relation between early Anger/Frustration and later ADHD symptom severity, suggesting that Anger/Frustration influences ADHD symptom severity through its impact on developing executive control. Early interventions targeting the harmful influences of negative emotionality or enhancing executive functioning may diminish later ADHD severity. PMID:26854505

Entropic-elasticity-controlled dissociation and energetic-elasticity-controlled rupture induce catch-to-slip bonds in cell-adhesion molecules.

PubMed

Wei, YuJie

2008-03-01

We develop a physical model to describe the kinetic behavior in cell-adhesion molecules. Unbinding of noncovalent biological bonds is assumed to occur by both bond dissociation and bond rupture. Such a decomposition of debonding processes is a space decomposition of the debonding events. Dissociation under thermal fluctuation is nondirectional in a three-dimensional space, and its energy barrier to escape is not influenced by a tensile force, but the microstates that could lead to dissociation are changed by the tensile force; rupture happens along the tensile force direction. An applied force effectively lowers the energy barrier to escape along the loading direction. The lifetime of the biological bond, due to the two concurrent off rates, may grow with increasing tensile force to a moderate amount and then decrease with further increasing load. We hypothesize that a catch-to-slip bond transition is a generic feature in biological bonds. The model also predicts that catch bonds in a more flexible molecular structure have longer lifetimes and need less force to be fully activated.

Does Mind Wandering Reflect Executive Function or Executive Failure? Comment on Smallwood and Schooler (2006) and Watkins (2008)

PubMed Central

McVay, Jennifer C.; Kane, Michael J.

2010-01-01

In this Comment, we contrast different conceptions of mind wandering that were presented in two recent theoretical reviews: Smallwood and Schooler (2006) and Watkins (2008). We also introduce a new perspective on the role of executive control in mind wandering by integrating empirical evidence presented in Smallwood and Schooler (2006) with two theoretical frameworks: Watkins’s (2008) elaborated control theory and Klinger’s (1971; 2009) current concerns theory. In contrast to the Smallwood-Schooler claim that mind-wandering recruits executive resources, we argue that mind wandering represents a failure of executive control and that it is dually determined by the presence of automatically generated thoughts in response to environmental and mental cues and the ability of the executive-control system to deal with this interference. We present empirical support for this view from experimental, neuroimaging, and individual-differences research. PMID:20192557

The effect of music-induced mood on attentional networks.

PubMed

Jiang, Jun; Scolaro, Ashley J; Bailey, Kira; Chen, Antao

2011-06-01

Attention network theory suggests that there are three separate neural networks that execute the discrete functions of alerting, orienting, and executive attention. Previous research on the influence of mood on attention has shown subtle and inconsistent results. The attention network theory may aid in clarifying the influence of mood on attention. The present study investigated the influence of mood on attentional networks in a normal population. Participants performed the Attention Network Test (ANT), which provides functional measures of alerting, orienting, and executive attention. Positive or negative mood was induced by listening to music with a positive or negative valence, respectively; neutral mood was induced by reading a collection of basic facts about China. The results revealed that negative mood led to a significantly higher alerting efficiency relative to other moods, while there were no significant mood effects on orienting or executive attention efficiency. According to the algorithm underlying the ANT, the higher alerting efficiency in the negative mood condition can be attributed to relatively greater benefits of cueing effects. The findings are discussed in the context of the noradrenergic system and of evolutionary significance. Specifically, the increase in the alerting function during negative mood states may be due to the modulation effect of negative mood on the noradrenergic system, and/or to the survival benefit resulting from an increase in automatic vigilance towards negative information. The current results suggest that as the influence of negative mood on attention appears to specifically consist in an enhanced alerting function, it may not be found in studies where the three attentional networks are not dissociated.

Happiness increases verbal and spatial working memory capacity where sadness does not: Emotion, working memory and executive control.

PubMed

Storbeck, Justin; Maswood, Raeya

2016-08-01

The effects of emotion on working memory and executive control are often studied in isolation. Positive mood enhances verbal and impairs spatial working memory, whereas negative mood enhances spatial and impairs verbal working memory. Moreover, positive mood enhances executive control, whereas negative mood has little influence. We examined how emotion influences verbal and spatial working memory capacity, which requires executive control to coordinate between holding information in working memory and completing a secondary task. We predicted that positive mood would improve both verbal and spatial working memory capacity because of its influence on executive control. Positive, negative and neutral moods were induced followed by completing a verbal (Experiment 1) or spatial (Experiment 2) working memory operation span task to assess working memory capacity. Positive mood enhanced working memory capacity irrespective of the working memory domain, whereas negative mood had no influence on performance. Thus, positive mood was more successful holding information in working memory while processing task-irrelevant information, suggesting that the influence mood has on executive control supersedes the independent effects mood has on domain-specific working memory.

Dissociative identity disorder and prepulse inhibition of the acoustic startle reflex

PubMed Central

Dale, Karl Yngvar; Flaten, Magne Arve; Elden, Åke; Holte, Arne

2008-01-01

A group of persons with dissociative identity disorder (DID) was compared with a group of persons with other dissociative disorders, and a group of nondiagnosed controls with regard to prepulse inhibition (PPI) of the acoustic startle reflex. The findings suggest maladaptive attentional processes at a controlled level, but not at a preattentive automatic level, in persons with DID. The prepulse occupied more controlled attentional resources in the DID group compared with the other two groups. Preattentive automatic processing, on the other hand, was normal in the DID group. Moreover, startle reflexes did not habituate in the DID group. In conclusion, increased PPI and delayed habituation is consistent with increased vigilance in individuals with DID. The present findings of reduced habituation of startle reflexes and increased PPI in persons with DID suggest the operation of a voluntary process that directs attention away from unpleasant or threatening stimuli. Aberrant voluntary attentional processes may thus be a defining characteristic in DID. PMID:18830396

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.

Coherent control of D2/H2 dissociative ionization by a mid-infrared two-color laser field

NASA Astrophysics Data System (ADS)

Wanie, Vincent; Ibrahim, Heide; Beaulieu, Samuel; Thiré, Nicolas; Schmidt, Bruno E.; Deng, Yunpei; Alnaser, Ali S.; Litvinyuk, Igor V.; Tong, Xiao-Min; Légaré, François

2016-01-01

Steering the electrons during an ultrafast photo-induced process in a molecule influences the chemical behavior of the system, opening the door to the control of photochemical reactions and photobiological processes. Electrons can be efficiently localized using a strong laser field with a well-designed temporal shape of the electric component. Consequently, many experiments have been performed with laser sources in the near-infrared region (800 nm) in the interest of studying and enhancing the electron localization. However, due to its limited accessibility, the mid-infrared (MIR) range has barely been investigated, although it allows to efficiently control small molecules and even more complex systems. To push further the manipulation of basic chemical mechanisms, we used a MIR two-color (1800 and 900 nm) laser field to ionize H2 and D2 molecules and to steer the remaining electron during the photo-induced dissociation. The study of this prototype reaction led to the simultaneous control of four fragmentation channels. The results are well reproduced by a theoretical model solving the time-dependent Schrödinger equation for the molecular ion, identifying the involved dissociation mechanisms. By varying the relative phase between the two colors, asymmetries (i.e., electron localization selectivity) of up to 65% were obtained, corresponding to enhanced or equivalent levels of control compared to previous experiments. Experimentally easier to implement, the use of a two-color laser field leads to a better electron localization than carrier-envelope phase stabilized pulses and applying the technique in the MIR range reveals more dissociation channels than at 800 nm.

Design and Analysis of A Multi-Backend Database System for Performance Improvement, Functionality Expansion and Capacity Growth. Part II.

DTIC Science & Technology

1981-08-01

of Transactions ..... . 29 5.5.2 Attached Execution of Transactions ........ ... 29 5.5.3 The Choice of Transaction Execution for Access Control...basic access control mech- anism for statistical security and value-dependent security. In Section 5.5, * we describe the process of execution of ...the process of request execution with access control for in- sert and non-insert requests in MDBS. We recall again (see Chapter 4) that the process

Unusual temperature dependence of the dissociative electron attachment cross section of 2-thiouracil

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

Kopyra, Janina; Abdoul-Carime, Hassan; Université Lyon 1, Villeurbanne

At low energies (<3 eV), molecular dissociation is controlled by dissociative electron attachment for which the initial step, i.e., the formation of the transient negative ion, can be initiated by shape resonance or vibrational Feshbach resonance (VFR) mediated by the formation of a dipole bound anion. The temperature dependence for shape-resonances is well established; however, no experimental information is available yet on the second mechanism. Here, we show that the dissociation cross section for VFRs mediated by the formation of a dipole bound anion decreases as a function of a temperature. The change remains, however, relatively small in the temperaturemore » range of 370-440 K but it might be more pronounced at the extended temperature range.« less

Self-Reported Sleep Disturbances in Patients with Dissociative Identity Disorder and Post-Traumatic Stress Disorder and How They Relate to Cognitive Failures and Fantasy Proneness

PubMed Central

van Heugten – van der Kloet, Dalena; Huntjens, Rafaele; Giesbrecht, Timo; Merckelbach, Harald

2014-01-01

Sleep disturbances, fantasy proneness, cognitive failures, and dissociative symptoms are related to each other. However, the co-occurrence of these phenomena has been primarily studied in non-clinical samples. We investigated the correlations between these phenomena in dissociative identity disorder (DID) patients, post-traumatic stress disorder (PTSD) patients, and healthy controls. Both patient groups reported more sleep problems and lower sleep quality and displayed higher levels of fantasy proneness and cognitive failures than controls. However, the two patient groups did not differ with regard to these variables. Moreover, a higher level of unusual sleep experiences tended to predict participants belonging to the DID group, while specifically a lower sleep quality and more cognitive failures tended to predict participants belonging to the PTSD group. PMID:24600412

Self-reported sleep disturbances in patients with dissociative identity disorder and post-traumatic stress disorder and how they relate to cognitive failures and fantasy proneness.

PubMed

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

2014-01-01

Sleep disturbances, fantasy proneness, cognitive failures, and dissociative symptoms are related to each other. However, the co-occurrence of these phenomena has been primarily studied in non-clinical samples. We investigated the correlations between these phenomena in dissociative identity disorder (DID) patients, post-traumatic stress disorder (PTSD) patients, and healthy controls. Both patient groups reported more sleep problems and lower sleep quality and displayed higher levels of fantasy proneness and cognitive failures than controls. However, the two patient groups did not differ with regard to these variables. Moreover, a higher level of unusual sleep experiences tended to predict participants belonging to the DID group, while specifically a lower sleep quality and more cognitive failures tended to predict participants belonging to the PTSD group.

In-situ visual observation for the formation and dissociation of methane hydrates in porous media by magnetic resonance imaging.

PubMed

Zhao, Jiafei; Lv, Qin; Li, Yanghui; Yang, Mingjun; Liu, Weiguo; Yao, Lei; Wang, Shenglong; Zhang, Yi; Song, Yongchen

2015-05-01

In this work, magnetic resonance imaging (MRI) was employed to observe the in-situ formation and dissociation of methane hydrates in porous media. Methane hydrate was formed in a high-pressure cell with controlled temperature, and then the hydrate was dissociated by thermal injection. The process was photographed by the MRI, and the pressure was recorded. The images confirmed that the direct visual observation was achieved; these were then employed to provide detailed information of the nucleation, growth, and decomposition of the hydrate. Moreover, the saturation of methane hydrate during the dissociation was obtained from the MRI intensity data. Our results showed that the hydrate saturation initially decreased rapidly, and then slowed down; this finding is in line with predictions based only on pressure. The study clearly showed that MRI is a useful technique to investigate the process of methane hydrate formation and dissociation in porous media. Copyright © 2015 Elsevier Inc. All rights reserved.

Child Maltreatment, Subsequent Non-Suicidal Self-Injury and the Mediating Roles of Dissociation, Alexithymia and Self-Blame

ERIC Educational Resources Information Center

Swannell, Sarah; Martin, Graham; Page, Andrew; Hasking, Penelope; Hazell, Philip; Taylor, Anne; Protani, Melinda

2012-01-01

Objective: Although child maltreatment is associated with later non-suicidal self-injury (NSSI), the mechanism through which it might lead to NSSI is not well understood. The current retrospective case-control study examined associations between child maltreatment and later NSSI, and investigated the mediating roles of dissociation, alexithymia,…

Decreased functional connectivity in an executive control network is related to impaired executive function in Internet gaming disorder.

PubMed

Dong, Guangheng; Lin, Xiao; Potenza, Marc N

2015-03-03

Resting brain spontaneous neural activities across cortical regions have been correlated with specific functional properties in psychiatric groups. Individuals with Internet gaming disorder (IGD) demonstrate impaired executive control. Thus, it is important to examine executive control networks (ECNs) during resting states and their relationships to executive control during task performance. Thirty-five IGD and 36 healthy control participants underwent a resting-state fMRI scan and performed a Stroop task inside and outside of the MRI scanner. Correlations between Stroop effect and functional connectivity among ECN regions of interest (ROIs) were calculated within and between groups. IGD subjects show lower functional connectivity in ECNs than do HC participants during resting state; functional-connectivity measures in ECNs were negatively correlated with Stroop effect and positively correlated with brain activations in executive-control regions across groups. Within groups, negative trends were found between Stroop effect and functional connectivity in ECNs in IGD and HC groups, separately; positive trends were found between functional connectivity in ECNs and brain activations in Stroop task in IGD and HC groups, separately. Higher functional connectivity in ECNs may underlie better executive control and may provide resilience with respect to IGD. Lower functional connectivity in ECNs may represent an important feature in understanding and treating IGD. Copyright © 2013 Elsevier Inc. All rights reserved.

Dissociation of methane on the surface of charged defective carbon nanotubes

NASA Astrophysics Data System (ADS)

Guo, Z. H.; Yan, X. H.; Xiao, Y.

2010-03-01

Based on the framework of density functional theory (CASTEP and DMOL 3 codes), we simulate the dissociation of methane (CH 4) molecule on the surface of charged defective carbon nanotubes (CNTs). The results display that a charged CNT with carbon (C) and molybdenum (Mo) dopants can effectively dissociate CH 4 molecule, and the adsorption strength of H and CH 3 can be controlled by the injected negative charges. Moreover, the barrier between the transition state (TS) and the reactant is 0.1014 eV, and a single imaginary frequency of -0.3 cm is found for the transition state structure.

Theory of "laser distillation" of enantiomers: purification of a racemic mixture of randomly oriented dimethylallene in a collisional environment.

PubMed

Gerbasi, David; Shapiro, Moshe; Brumer, Paul

2006-02-21

Enantiomeric control of 1,3 dimethylallene in a collisional environment is examined. Specifically, our previous "laser distillation" scenario wherein three perpendicular linearly polarized light fields are applied to excite a set of vib-rotational eigenstates of a randomly oriented sample is considered. The addition of internal conversion, dissociation, decoherence, and collisional relaxation mimics experimental conditions and molecular decay processes. Of greatest relevance is internal conversion which, in the case of dimethylallene, is followed by molecular dissociation. For various rates of internal conversion, enantiomeric control is maintained in this scenario by a delicate balance between collisional relaxation of excited dimethylallene that enhances control and collisional dephasing, which diminishes control.

Dissociation During Intense Military Stress is Related to Subsequent Somatic Symptoms in Women

PubMed Central

Steffian, Lisa; Steffian, George; Doran, Anthony P.; Rasmusson, Ann M.; Morgan, CA

2007-01-01

Background: Research studies of the female response to intense stress are under-represented in the scientific literature; indeed, publications in female humans and animals number half those in male subjects. In addition, women have only recently entered more dangerous professions that were historically limited to men. The US Navy's survival course, therefore, offers a unique opportunity to examine, in a controlled manner, individual differences in the human female response to acute and realistic military stress. Method: The current study assessed the nature and prevalence of dissociative symptoms and other aspects of adaptive function in healthy female subjects experiencing acute, intense stress during US Navy survival training. Cognitive dissociation and previous exposure to traumatic events were assessed at baseline in 32 female service members prior to Navy survival training. At the conclusion of training, retrospectively rated levels of dissociation during peak training stress and current health symptoms were assessed. Results: Female subjects reported previous trauma (35%) and at least one symptom of dissociation at baseline prior to training (47%). Eighty-eight percent of subjects reported experiencing multiple symptoms of dissociation during peak training stress. Post-stress dissociation scores and stress-induced increases in dissociation, as well as prior cumulative exposure to potentially traumatic events, were significant predictors of post-stress health symptoms. Discussion: In this study, increases in dissociative symptoms during intense training stress, post-stress dissociation symptom levels, and prior cumulative exposure to stressful, potentially traumatic events predicted post-stress health symptoms in women. Prior studies in men have demonstrated correlations between neurobiological responses to stress and stress-associated levels of dissociation. Thus future studies in larger samples of women are needed to investigate the relationship between prior stress exposure, alterations in neurobiological responses to stress and potentially related alterations in neuropsychological and physical reactions to stress. PMID:20805901

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).

Morphosyntactic Production and Verbal Working Memory: Evidence From Greek Aphasia and Healthy Aging.

PubMed

Fyndanis, Valantis; Arcara, Giorgio; Christidou, Paraskevi; Caplan, David

2018-05-17

The present work investigated whether verbal working memory (WM) affects morphosyntactic production in configurations that do not involve or favor similarity-based interference and whether WM interacts with verb-related morphosyntactic categories and/or cue-target distance (locality). It also explored whether the findings related to the questions above lend support to a recent account of agrammatic morphosyntactic production: Interpretable Features' Impairment Hypothesis (Fyndanis, Varlokosta, & Tsapkini, 2012). A sentence completion task testing production of subject-verb agreement, tense/time reference, and aspect in local and nonlocal conditions and two verbal WM tasks were administered to 8 Greek-speaking persons with agrammatic aphasia (PWA) and 103 healthy participants. The 3 morphosyntactic categories dissociated in both groups (agreement > tense > aspect). A significant interaction emerged in both groups between the 3 morphosyntactic categories and WM. There was no main effect of locality in either of the 2 groups. At the individual level, all 8 PWA exhibited dissociations between agreement, tense, and aspect, and effects of locality were contradictory. Results suggest that individuals with WM limitations (both PWA and healthy older speakers) show dissociations between the production of verb-related morphosyntactic categories. WM affects performance shaping the pattern of morphosyntactic production (in Greek: subject-verb agreement > tense > aspect). The absence of an effect of locality suggests that executive capacities tapped by WM tasks are involved in morphosyntactic processing of demanding categories even when the cue is adjacent to the target. Results are consistent with the Interpretable Features' Impairment Hypothesis (Fyndanis et al., 2012). https://doi.org/10.23641/asha.6024428.

Computer Program for the Design and Off-Design Performance of Turbojet and Turbofan Engine Cycles

NASA Technical Reports Server (NTRS)

Morris, S. J.

1978-01-01

The rapid computer program is designed to be run in a stand-alone mode or operated within a larger program. The computation is based on a simplified one-dimensional gas turbine cycle. Each component in the engine is modeled thermo-dynamically. The component efficiencies used in the thermodynamic modeling are scaled for the off-design conditions from input design point values using empirical trends which are included in the computer code. The engine cycle program is capable of producing reasonable engine performance prediction with a minimum of computer execute time. The current computer execute time on the IBM 360/67 for one Mach number, one altitude, and one power setting is about 0.1 seconds. about 0.1 seconds. The principal assumption used in the calculation is that the compressor is operated along a line of maximum adiabatic efficiency on the compressor map. The fluid properties are computed for the combustion mixture, but dissociation is not included. The procedure included in the program is only for the combustion of JP-4, methane, or hydrogen.

The rat's not for turning: Dissociating the psychological components of cognitive inflexibility☆

PubMed Central

Nilsson, Simon R.O.; Alsiö, Johan; Somerville, Elizabeth M.; Clifton, Peter G.

2015-01-01

Executive function is commonly assessed by assays of cognitive flexibility such as reversal learning and attentional set-shifting. Disrupted performance in these assays, apparent in many neuropsychiatric disorders, is frequently interpreted as inability to overcome prior associations with reward. However, non-rewarded or irrelevant associations may be of considerable importance in both discrimination learning and cognitive flexibility. Non-rewarded associations can have greater influence on choice behaviour than rewarded associations in discrimination learning. Pathology-related deficits in cognitive flexibility can produce selective disruptions to both the processing of irrelevant associations and associations with reward. Genetic and pharmacological animal models demonstrate that modulation of reversal learning may result from alterations in either rewarded or non-rewarded associations. Successful performance in assays of cognitive flexibility can therefore depend on a combination of rewarded, non-rewarded, and irrelevant associations derived from previous learning, accounting for some inconsistencies observed in the literature. Taking this combination into account may increase the validity of animal models and may also reveal pathology-specific differences in problem solving and executive function. PMID:26112128

Links between theory of mind and executive function in young children with autism: clues to developmental primacy.

PubMed

Pellicano, Elizabeth

2007-07-01

There has been much theoretical discussion of a functional link between theory of mind (ToM) and executive function (EF) in autism. This study sought to establish the relationship between ToM and EF in young children with autism (M = 5 years, 6 months) and to examine issues of developmental primacy. Thirty children with autism and 40 typically developing children, matched on age and ability, were assessed on a battery of tasks measuring ToM (1st- and 2nd-order false belief) and components of EF (planning, set shifting, inhibition). A significant correlation emerged between ToM and EF variables in the autism group, independent of age and ability, while ToM and higher order planning ability remained significantly related in the comparison group. Examination of the pattern of ToM-EF impairments in the autism group revealed dissociations in 1 direction only: impaired ToM with intact EF. These findings support the view that EF may be 1 important factor in the advancement of ToM understanding in autism. The theoretical implications of these findings are discussed. Copyright 2007 APA.

The effect of carbon-chain oxygenation in the carbon-carbon dissociation.

PubMed

Dos Santos, Lisandra Paulino; Baptista, Leonardo

2018-06-01

Currently, there is a trend of moving away from the use of fossil fuels to the use of biofuels. This modification changes the molecular structure of gasoline and diesel constituents, which should impact pollutant emissions and engine efficiency. An important property of automotive fuels is the resistance to autoignition. The goal of the present work is to evaluate thermochemical and kinetic parameters that govern the carbon-carbon bond dissociation and relate these parameters, in conjunction with molecular properties, to autoignition resistance. Three model reactions were investigated in the present work: dissociation of ethane, ethanol, and ethanal. All studies were conducted at the multiconfigurational level of theory, and the rate coefficients were evaluated from 300 to 2000 K. The comparison of dissociation energies and Arrhenius expressions indicates that autoignition resistance is related to the kinetic control of dissociation reactions and it is possible to relate the higher octane number of ethanol based fuels to the kinetics parameters of carbon-carbon bond fission. Graphical abstract Effect of the functional group in the Arrhenius parameters of the C-C dissociation. Arrhenius curves calculated at NEVPT2(6,6)/6-311G(2df,2pd).

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.

Improved circadian sleep-wake cycle in infants fed a day/night dissociated formula milk.

PubMed

Cubero, J; Narciso, D; Aparicio, S; Garau, C; Valero, V; Rivero, M; Esteban, S; Rial, R; Rodríguez, A B; Barriga, C

2006-06-01

On the basis of the circadian nutritional variations present in breast milk, and of the implications for the sleep/wake cycle of the nutrients present in infant formula milks, we designed a formula milk nutritionally dissociated into a Day/Night composition. The goal was to improve the bottle-fed infant's sleep/wake circadian rhythm. A total of 21 infants aged 4-20 weeks with sleeping difficulties were enrolled in the three-week duration study. The sleep analysis was performed using an actimeter (Actiwatch) placed on an ankle of each infant to uninterruptedly record movements during the three weeks. The dissociated Day milk, designed to be administered from 06:00 to 18:00, contained low levels of tryptophan (1.5g/100g protein) and carbohydrates, high levels of proteins, and the nucleotides Cytidine 5 monophosphate, Guanosine 5 monophosphate and Inosine 5 monophosphate. The dissociated Night milk, designed to be administered from 18.00 to 06.00, contained high levels of tryptophan (3.4g/100g protein) and carbohydrates, low levels of protein, and the nucleotides Adenosine 5 monophosphate and Uridine 5 monophosphate. Three different milk-feeding experiments were performed in a double-blind procedure covering three weeks. In week 1 (control), the infants received both by day and by night a standard formula milk; in week 2 (inverse control), they received the dissociated milk inversely (Night/Day instead of Day/Night); and in week 3, they received the Day/Night dissociated formula concordant with the formula design. When the infants were receiving the Day/Night dissociated milk in concordance with their environment, they showed improvement in all the nocturnal sleep parameters analyzed: total hours of sleep, sleep efficiency, minutes of nocturnal immobility, nocturnal awakenings, and sleep latency. In conclusion, the use of a chronobiologically adjusted infant formula milk seems to be effective in improving the consolidation of the circadian sleep/wake cycle in bottle-fed infants.

Spaceborne computer executive routine functional design specification. Volume 2: Computer executive design for space station/base

NASA Technical Reports Server (NTRS)

Kennedy, J. R.; Fitzpatrick, W. S.

1971-01-01

The computer executive functional system design concepts derived from study of the Space Station/Base are presented. Information Management System hardware configuration as directly influencing the executive design is reviewed. The hardware configuration and generic executive design requirements are considered in detail in a previous report (System Configuration and Executive Requirements Specifications for Reusable Shuttle and Space Station/Base, 9/25/70). This report defines basic system primitives and delineates processes and process control. Supervisor states are considered for describing basic multiprogramming and multiprocessing systems. A high-level computer executive including control of scheduling, allocation of resources, system interactions, and real-time supervisory functions is defined. The description is oriented to provide a baseline for a functional simulation of the computer executive system.

3 CFR 13556 - Executive Order 13556 of November 4, 2010. Controlled Unclassified Information

Code of Federal Regulations, 2011 CFR

2011-01-01

.... Controlled Unclassified Information 13556 Order 13556 Presidential Documents Executive Orders Executive Order... information, such as information that involves privacy, security, proprietary business interests, and law... safeguarding of documents, led to unclear or unnecessarily restrictive dissemination policies, and created...

Banishing the Control Homunculi in Studies of Action Control and Behavior Change

PubMed Central

Verbruggen, Frederick; McLaren, Ian P. L.; Chambers, Christopher D.

2014-01-01

For centuries, human self-control has fascinated scientists and nonscientists alike. Current theories often attribute it to an executive control system. But even though executive control receives a great deal of attention across disciplines, most aspects of it are still poorly understood. Many theories rely on an ill-defined set of “homunculi” doing jobs like “response inhibition” or “updating” without explaining how they do so. Furthermore, it is not always appreciated that control takes place across different timescales. These two issues hamper major advances. Here we focus on the mechanistic basis for the executive control of actions. We propose that at the most basic level, action control depends on three cognitive processes: signal detection, action selection, and action execution. These processes are modulated via error-correction or outcome-evaluation mechanisms, preparation, and task rules maintained in working and long-term memory. We also consider how executive control of actions becomes automatized with practice and how people develop a control network. Finally, we discuss how the application of this unified framework in clinical domains can increase our understanding of control deficits and provide a theoretical basis for the development of novel behavioral change interventions. PMID:25419227

The Prefrontal Model Revisited: Double Dissociations Between Young Sleep Deprived and Elderly Subjects on Cognitive Components of Performance

PubMed Central

Tucker, Adrienne M.; Stern, Yaakov; Basner, Robert C.; Rakitin, Brian C.

2011-01-01

Study Objectives: The prefrontal model suggests that total sleep deprivation (TSD) and healthy aging produce parallel cognitive deficits. Here we decompose global performance on two common tasks into component measures of specific cognitive processes to pinpoint the source of impairments in elderly and young TSD participants relative to young controls and to each other. Setting: The delayed letter recognition task (DLR) was performed in 3 studies. The psychomotor vigilance task (PVT) was performed in 1 of the DLR studies and 2 additional studies. Subjects: For DLR, young TSD (n = 20, age = 24.60 ± 0.62 years) and young control (n = 17, age = 24.00 ± 2.42); elderly (n = 26, age = 69.92 ± 1.06). For the PVT, young TSD (n = 18, age = 26.65 ± 4.57) and young control (n = 16, age = 25.19 ± 2.90); elderly (n = 21, age = 71.1 ± 4.92). Measurements and Results: Both elderly and young TSD subjects displayed impaired reaction time (RT), our measure of global performance, on both tasks relative to young controls. After decomposing global performance on the DLR, however, a double dissociation was observed as working memory scanning speed was impaired only in elderly subjects while other components of performance were impaired only by TSD. Similarly, for the PVT a second double dissociation was observed as vigilance impairments were present only in TSD while short-term response preparation effects were altered only in the elderly. Conclusions: The similarity between TSD and the elderly in impaired performance was evident only when examining global RT. In contrast, when specific cognitive components were examined double dissociations were observed between TSD and elderly subjects. This demonstrates the heterogeneity in those cognitive processes impaired in TSD versus the elderly. Citation: Tucker AM; Stern Y; Basner RC; Rakitin BC. The prefrontal model revisited: double dissociations between young sleep deprived and elderly subjects on cognitive components of performance. SLEEP 2011;34(8):1039-1050. PMID:21804666

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.

Dissociable frontostriatal white matter connectivity underlies reward and motor impulsivity.

PubMed

Hampton, William H; Alm, Kylie H; Venkatraman, Vinod; Nugiel, Tehila; Olson, Ingrid R

2017-04-15

Dysfunction of cognitive control often leads to impulsive decision-making in clinical and healthy populations. Some research suggests that a generalized cognitive control mechanism underlies the ability to modulate various types of impulsive behavior, while other evidence suggests different forms of impulsivity are dissociable, and rely on distinct neural circuitry. Past research consistently implicates several brain regions, such as the striatum and portions of the prefrontal cortex, in impulsive behavior. However the ventral and dorsal striatum are distinct in regards to function and connectivity. Nascent evidence points to the importance of frontostriatal white matter connectivity in impulsivity, yet it remains unclear whether particular tracts relate to different control behaviors. Here we used probabilistic tractography of diffusion imaging data to relate ventral and dorsal frontostriatal connectivity to reward and motor impulsivity measures. We found a double dissociation such that individual differences in white matter connectivity between the ventral striatum and the ventromedial prefrontal cortex and dorsolateral prefrontal cortex was associated with reward impulsivity, as measured by delay discounting, whereas connectivity between dorsal striatum and supplementary motor area was associated with motor impulsivity, but not vice versa. Our findings suggest that (a) structural connectivity can is associated with a large amount of behavioral variation; (b) different types of impulsivity are driven by dissociable frontostriatal neural circuitry. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

fMRI functional connectivity of the periaqueductal gray in PTSD and its dissociative subtype.

PubMed

Harricharan, Sherain; Rabellino, Daniela; Frewen, Paul A; Densmore, Maria; Théberge, Jean; McKinnon, Margaret C; Schore, Allan N; Lanius, Ruth A

2016-12-01

Posttraumatic stress disorder (PTSD) is associated with hyperarousal and active fight or flight defensive responses. By contrast, the dissociative subtype of PTSD, characterized by depersonalization and derealization symptoms, is frequently accompanied by additional passive or submissive defensive responses associated with autonomic blunting. Here, the periaqueductal gray (PAG) plays a central role in defensive responses, where the dorsolateral (DL-PAG) and ventrolateral PAG (VL-PAG) are thought to mediate active and passive defensive responses, respectively. We examined PAG subregion (dorsolateral and ventrolateral) resting-state functional connectivity in three groups: PTSD patients without the dissociative subtype ( n  = 60); PTSD patients with the dissociative subtype ( n  = 37); and healthy controls ( n  = 40) using a seed-based approach via PickAtlas and SPM12. All PTSD patients showed extensive DL- and VL-PAG functional connectivity at rest with areas associated with emotional reactivity and defensive action as compared to controls ( n  = 40). Although all PTSD patients demonstrated DL-PAG functional connectivity with areas associated with initiation of active coping strategies and hyperarousal (e.g., dorsal anterior cingulate; anterior insula), only dissociative PTSD patients exhibited greater VL-PAG functional connectivity with brain regions linked to passive coping strategies and increased levels of depersonalization (e.g., temporoparietal junction; rolandic operculum). These findings suggest greater defensive posturing in PTSD patients even at rest and demonstrate that those with the dissociative subtype show unique patterns of PAG functional connectivity when compared to those without the subtype. Taken together, these findings represent an important first step toward identifying neural and behavioral targets for therapeutic interventions that address defensive strategies in trauma-related disorders.

The Role of Control Functions in Mentalizing: Dual-Task Studies of Theory of Mind and Executive Function

ERIC Educational Resources Information Center

Bull, Rebecca; Phillips, Louise H.; Conway, Claire A.

2008-01-01

Conflicting evidence has arisen from correlational studies regarding the role of executive control functions in Theory of Mind. The current study used dual-task manipulations of executive functions (inhibition, updating and switching) to investigate the role of these control functions in mental state and non-mental state tasks. The "Eyes"…

Aerobic Fitness and Cognitive Development: Event-Related Brain Potential and Task Performance Indices of Executive Control in Preadolescent Children

ERIC Educational Resources Information Center

Hillman, Charles H.; Buck, Sarah M.; Themanson, Jason R.; Pontifex, Matthew B.; Castelli, Darla M.

2009-01-01

The relationship between aerobic fitness and executive control was assessed in 38 higher- and lower-fit children (M[subscript age] = 9.4 years), grouped according to their performance on a field test of aerobic capacity. Participants performed a flanker task requiring variable amounts of executive control while event-related brain potential…

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.

Application driven interface generation for EASIE. M.S. Thesis

NASA Technical Reports Server (NTRS)

Kao, Ya-Chen

1992-01-01

The Environment for Application Software Integration and Execution (EASIE) provides a user interface and a set of utility programs which support the rapid integration and execution of analysis programs about a central relational database. EASIE provides users with two basic modes of execution. One of them is a menu-driven execution mode, called Application-Driven Execution (ADE), which provides sufficient guidance to review data, select a menu action item, and execute an application program. The other mode of execution, called Complete Control Execution (CCE), provides an extended executive interface which allows in-depth control of the design process. Currently, the EASIE system is based on alphanumeric techniques only. It is the purpose of this project to extend the flexibility of the EASIE system in the ADE mode by implementing it in a window system. Secondly, a set of utilities will be developed to assist the experienced engineer in the generation of an ADE application.

Numerical studies of depressurization-induced gas production from an interbedded marine turbidite gas hydrate reservoir model

USGS Publications Warehouse

Myshakin, Evgeniy; Lin, Jeen-Shang; Uchida, Shun; Seol, Yongkoo; Collett, Timothy S.; Boswell, Ray

2017-01-01

The numerical simulation of thin hydrate-bearing sand layers interbedded with mud layers is investigated. In this model, the lowest hydrate layer occurs at the base of gas hydrate stability and overlies a thinly-interbedded saline aquifer. The predicted gas rates reach 6.25 MMscf/day (1.77 x 105 m3 /day) after 90 days of continuous depressurization with manageable water production. Development of horizontal dissociating interfaces between hydrate-bearing sand and mud layers is a primary determinant of reservoir performance. A set of simulations has been executed to assess uncertainty in in situ permeability and to determine the impact of the saline aquifer on productivity.

Seeing conflict and engaging control: Experience with contrastive language benefits executive function in preschoolers

PubMed Central

Doebel, Sabine; Zelazo, Philip David

2016-01-01

Engaging executive function often requires overriding a prepotent response in favor of a conflicting but adaptive one. Language may play a key role in this ability by supporting integrated representations of conflicting rules. We tested whether experience with contrastive language that could support such representations benefits executive function in 3-year-old children. Children who received brief experience with language highlighting contrast between objects, attributes, and actions showed greater executive function on two of three ‘conflict’ executive function tasks than children who received experience with contrasting stimuli only and children who read storybooks with the experimenter, controlling for baseline executive function. Experience with contrasting stimuli did not benefit executive function relative to reading books with the experimenter, indicating experience with contrastive language, rather than experience with contrast generally, was key. Experience with contrastive language also boosted spontaneous attention to contrast, consistent with improvements in representing contrast. These findings indicate a role for language in executive function that is consistent with the Cognitive Complexity and Control theory's key claim that coordinating conflicting rules is critical to overcoming perseveration, and suggest new ideas for testing theories of executive function. PMID:27658118

Seeing conflict and engaging control: Experience with contrastive language benefits executive function in preschoolers.

PubMed

Doebel, Sabine; Zelazo, Philip David

2016-12-01

Engaging executive function often requires overriding a prepotent response in favor of a conflicting but adaptive one. Language may play a key role in this ability by supporting integrated representations of conflicting rules. We tested whether experience with contrastive language that could support such representations benefits executive function in 3-year-old children. Children who received brief experience with language highlighting contrast between objects, attributes, and actions showed greater executive function on two of three 'conflict' executive function tasks than children who received experience with contrasting stimuli only and children who read storybooks with the experimenter, controlling for baseline executive function. Experience with contrasting stimuli did not benefit executive function relative to reading books with the experimenter, indicating experience with contrastive language, rather than experience with contrast generally, was key. Experience with contrastive language also boosted spontaneous attention to contrast, consistent with improvements in representing contrast. These findings indicate a role for language in executive function that is consistent with the Cognitive Complexity and Control theory's key claim that coordinating conflicting rules is critical to overcoming perseveration, and suggest new ideas for testing theories of executive function. Copyright © 2016 Elsevier B.V. All rights reserved.

Moderating influence of dominant attentional style and exercise intensity on responses to asynchronous music.

PubMed

Hutchinson, Jasmin C; Karageorghis, Costas I

2013-12-01

We examined independent and combined influences of asynchronous music and dominant attentional style (DAS) on psychological and psychophysical variables during exercise using mixed methods. Participants (N = 34) were grouped according to DAS and completed treadmill runs at three intensities (low, moderate, high) crossed with three music conditions (motivational, oudeterous, no-music control). State attentional focus shifted from dissociative to associative with increasing intensity and was most aligned with DAS during moderate-intensity exercise. Both music conditions facilitated dissociation at low-to-moderate intensities. At high exercise intensity, both music conditions were associated with reduced RPE among participants with an associative DAS. Dissociators reported higher RPE overall during moderate and high intensities. Psychological responses were most positive in the motivational condition, followed by oudeterous and control. Findings illustrate the relevance of individual differences in DAS as well as task intensity and duration when selecting music for exercise.

Memory transfer for emotionally valenced words between identities in dissociative identity disorder.

PubMed

Huntjens, Rafaële J C; Peters, Madelon L; Woertman, Liesbeth; van der Hart, Onno; Postma, Albert

2007-04-01

The present study aimed to determine interidentity retrieval of emotionally valenced words in dissociative identity disorder (DID). Twenty-two DID patients participated together with 25 normal controls and 25 controls instructed to simulate DID. Two wordlists A and B were constructed including neutral, positive and negative material. List A was shown to one identity, while list B was shown to another identity claiming total amnesia for the words learned by the first identity. The identity claiming amnesia was tested for intrusions from list A words into the recall of words from list B and recognition of the words learned by both identities. Test results indicated no evidence of total interidentity amnesia for emotionally valenced material in DID. It is argued that dissociative amnesia in DID may more adequately be described as a disturbance in meta-memory functioning instead of an actual retrieval inability.

Age-related changes in strategic variations during arithmetic problem solving: The role of executive control.

PubMed

Hinault, T; Lemaire, P

2016-01-01

In this review, we provide an overview of how age-related changes in executive control influence aging effects in arithmetic processing. More specifically, we consider the role of executive control in strategic variations with age during arithmetic problem solving. Previous studies found that age-related differences in arithmetic performance are associated with strategic variations. That is, when they accomplish arithmetic problem-solving tasks, older adults use fewer strategies than young adults, use strategies in different proportions, and select and execute strategies less efficiently. Here, we review recent evidence, suggesting that age-related changes in inhibition, cognitive flexibility, and working memory processes underlie age-related changes in strategic variations during arithmetic problem solving. We discuss both behavioral and neural mechanisms underlying age-related changes in these executive control processes. © 2016 Elsevier B.V. All rights reserved.

Sustained Attention and Age Predict Inhibitory Control during Early Childhood

ERIC Educational Resources Information Center

Reck, Sarah G.; Hund, Alycia M.

2011-01-01

Executive functioning skills develop rapidly during early childhood. Recent research has focused on specifying this development, particularly predictors of executive functioning skills. Here we focus on sustained attention as a predictor of inhibitory control, one key executive functioning component. Although sustained attention and inhibitory…

Differential age-related decline in conflict-driven task-set shielding from emotional versus non-emotional distracters.

PubMed

Monti, Jim M; Weintraub, Sandra; Egner, Tobias

2010-05-01

While normal aging is associated with a marked decline in cognitive abilities, such as memory and executive functions, recent evidence suggests that control processes involved in regulating responses to emotional stimuli may remain well-preserved in the elderly. However, neither the precise nature of these preserved control processes, nor their domain-specificity with respect to comparable non-emotional control processes, are currently well-established. Here, we tested the hypothesis of domain-specific preservation of emotional control in the elderly by employing two closely matched behavioral tasks that assessed the ability to shield the processing of task-relevant stimulus information from competition by task-irrelevant distracter stimuli that could be either non-emotional or emotional in nature. The efficacy of non-emotional versus emotional task-set shielding, gauged via the 'conflict adaptation effect', was compared between cohorts of healthy young adults, healthy elderly adults, and individuals diagnosed with probable Alzheimer's disease (PRAD), age-matched to the elderly subjects. It was found that, compared to the young adult cohort, the healthy elderly displayed deficits in task-set shielding in the non-emotional but not in the emotional task, whereas PRAD subjects displayed impaired performance in both tasks. These results provide new evidence that healthy aging is associated with a domain-specific preservation of emotional control functions, specifically, the shielding of a current task-set from interference by emotional distracter stimuli. This selective preservation of function supports the notion of partly dissociable affective control mechanisms, and may either reflect different time-courses of degeneration in the neuroanatomical circuits mediating task-set maintenance in the face of non-emotional versus emotional distracters, or a motivational shift towards affective processing in the elderly. 2010 Elsevier Ltd. All rights reserved.

Self-injurious behavior in adolescent girls. Association with psychopathology and neuropsychological functions.

PubMed

Ohmann, S; Schuch, B; Konig, M; Blaas, S; Fliri, C; Popow, C

2008-01-01

Self-injurious behavior (SIB) is increasingly popular in psychically ill adolescents, especially in girls with posttraumatic stress (PTSD) and personality disorders. Adolescents with SIB frequently exhibit neurofunctional and psychopathological deficits. We speculated that specific neuropsychological deficits and temperamental factors could predispose patients to SIB and prospectively explored adolescent psychiatric patients with and without SIB in order to find out differences in psychopathology, and neuropsychological or temperamental factors. Ninety-nine psychically ill adolescent girls with SIB, aged 12-19 years and treated at our clinic, were prospectively recruited during a period of 5.5 years (1999-2005). The clinical (ICD-10) diagnoses were mainly substance abuse, eating disorders, depression, PTSD and personality disorders. The control group was also prospectively recruited during the same period and consisted of 77 girls with similar diagnoses and ages but no SIB. All patients were subjected to the same selection of clinical and neuropsychological tests, mainly self-rating questionnaires and tests evaluating executive functions. Adolescent girls with psychiatric disease and SIB were more severely traumatized and depressed. They reported severe emotional and behavioral problems and deficits of self-regulation. In addition, their parents more frequently had psychiatric problems. Temperament, intelligence, investigated executive functions and presence of dissociative symptoms were not different in patients with and without SIB. We could not verify our primary hypothesis that SIB is related to specific neuropsychological deficits or temperamental factors. SIB was associated with traumatic experience, depression, problems of self-regulation and parental psychiatric disease. The prevention of SIB should therefore focus on improving affect regulation, the management of emotional distress and problem-solving strategies. (c) 2008 S. Karger AG, Basel

Beyond the dual pathway model: evidence for the dissociation of timing, inhibitory, and delay-related impairments in attention-deficit/hyperactivity disorder.

PubMed

Sonuga-Barke, Edmund; Bitsakou, Paraskevi; Thompson, Margaret

2010-04-01

The dual pathway model explains neuro-psychological heterogeneity in Attention Deficit/Hyperactivity Disorder (ADHD) in terms of dissociable cognitive and motivational deficits each affecting some but not other patients. We explore whether deficits in temporal processing might constitute a third dissociable neuropsychological component of ADHD. Nine tasks designed to tap three domains (inhibitory control, delay aversion and temporal processing) were administered to ADHD probands (n=71; ages 6 to 17 years), their siblings (n=71; 65 unaffected by ADHD) and a group of non-ADHD controls (n=50). IQ and working memory were measured. Temporal processing, inhibitory control and delay-related deficits represented independent neuropsychological components. ADHD children differed from controls on all factors. For ADHD patients, the co-occurrence of inhibitory, temporal processing and delay-related deficits was no greater than expected by chance with substantial groups of patients showing only one problem. Domain-specific patterns of familial co-segregation provided evidence for the validity of neuropsychological subgroupings. The current results illustrate the neuropsychological heterogeneity in ADHD and initial support for a triple pathway model. The findings need to be replicated in larger samples.

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.

Collaborative Memory and Part-Set Cuing Impairments: The Role of Executive Depletion in Modulating Retrieval Disruption

PubMed Central

Barber, Sarah J.; Rajaram, Suparna

2011-01-01

When people are exposed to a subset of previously studied list items they recall fewer of the remaining items compared to a condition where none of the studied items are provided during recall. This occurs both when the subset of items is provided by the experimenter (i.e., the part-set cuing deficit in individual recall) and when they are provided during the course of a collaborative discussion (i.e., the collaborative inhibition effect in group recall). Previous research has identified retrieval disruption as a common mechanism underlying both effects; however, less is known about the factors that may make individuals susceptible to such retrieval disruption. In the current studies we tested one candidate factor, namely, executive control. Using an executive depletion paradigm we directly manipulated an individual’s level of executive control during retrieval. Results revealed no direct role of executive depletion in modulating retrieval disruption. In contrast, executive control abilities were indirectly related to retrieval disruption through their influence at encoding. Together, these results suggest that executive control does not directly affect retrieval disruption at the retrieval stage, and that the role of this putative mechanism may be limited to the encoding stage. PMID:21678155

Creative thinking in schizophrenia: the role of executive dysfunction and symptom severity.

PubMed

Abraham, Anna; Windmann, Sabine; McKenna, Peter; Güntürkün, Onur

2007-05-01

This study examines the notion of enhanced creative thinking in schizophrenia and determines the mediating role of executive dysfunction and symptom severity in this relationship. Patients with chronic schizophrenia (n=28) were assessed on varied facets of creative cognition and standard tests of executive control relative to matched healthy control participants (n=18). Multivariate analyses revealed poorer performance by the patient group across almost all creative and executive function measures, except in the ability to be unconstrained by the influence of restrictive examples. Symptom-based contrasts using partial correlations revealed that differences were most extensive in the presence of thought disorder. Using hierarchical regression analyses, performance on the executive function tasks was found to play a mediatory role on specific aspects of creative cognition. Results are at odds with the popular notion of enhanced creative thinking in schizophrenia, but elucidate complex interactions between executive control and certain facets of creative thinking. In particular, performance of the schizophrenia group on measures that tap creativity elements of fluency and relevance were either partially or fully mediated by their performance on the executive control tasks, but this was not true of measures of originality.

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.

Episodic memory and executive functioning in currently depressed patients compared to healthy controls.

PubMed

Pauls, Franz; Petermann, Franz; Lepach, Anja Christina

2015-01-01

At present, little is still known about the link between depression, memory and executive functioning. This study examined whether there are memory-related impairments in depressed patients and whether the size of such deficits depends on the age group and on specific types of cognitive measures. Memory performances of 215 clinically depressed patients were compared to the data of a matched control sample. Regression analyses were performed to determine the extent to which executive dysfunctions contributed to episodic memory impairments. When compared with healthy controls, significantly lower episodic memory and executive functioning performances were found for depressed patients of all age groups. Effect sizes appeared to vary across different memory and executive functioning measures. The extent to which executive dysfunctions could explain episodic memory impairments varied depending on the type of measure examined. These findings emphasise the need to consider memory-related functioning of depressed patients in the context of therapeutic treatments.

The contribution of executive functions to emergent mathematic skills in preschool children.

PubMed

Espy, Kimberly Andrews; McDiarmid, Melanie M; Cwik, Mary F; Stalets, Melissa Meade; Hamby, Arlena; Senn, Theresa E

2004-01-01

Mathematical ability is related to both activation of the prefrontal cortex in neuroimaging studies of adults and to executive functions in school-age children. The purpose of this study was to determine whether executive functions were related to emergent mathematical proficiency in preschool children. Preschool children (N = 96) were administered an executive function battery that was reduced empirically to working memory (WM), inhibitory control (IC), and shifting abilities by calculating composite scores derived from principal component analysis. Both WM and IC predicted early arithmetic competency, with the observed relations robust after controlling statistically for child age, maternal education, and child vocabulary. Only IC accounted for unique variance in mathematical skills, after the contribution of other executive functions were controlled statistically as well. Specific executive functions are related to emergent mathematical proficiency in this age range. Longitudinal studies using structural equation modeling are necessary to better characterize these ontogenetic relations.

Analysis of slow- and fast-α band asymmetry during performance of a saccadic eye movement task: dissociation between memory- and attention-driven systems.

PubMed

Sanfim, Antonio; Velasques, Bruna; Machado, Sergio; Arias-Carrión, Oscar; Paes, Flávia; Teixeira, Silmar; Santos, Joana Luz; Bittencourt, Juliana; Basile, Luis F; Cagy, Mauricio; Piedade, Roberto; Sack, Alexander T; Nardi, Antonio Egídio; Ribeiro, Pedro

2012-01-15

This study aimed at analyzing the relationship between slow- and fast-alpha asymmetry within frontal cortex and the planning, execution and voluntary control of saccadic eye movements (SEM), and quantitative electroencephalography (qEEG) was recorded using a 20-channel EEG system in 12 healthy participants performing a fixed (i.e., memory-driven) and a random SEM (i.e., stimulus-driven) condition. We find main effects for SEM condition in slow- and fast-alpha asymmetry at electrodes F3-F4, which are located over premotor cortex, specifically a negative asymmetry between conditions. When analyzing electrodes F7-F8, which are located over prefrontal cortex, we found a main effect for condition in slow-alpha asymmetry, particularly a positive asymmetry between conditions. In conclusion, the present approach supports the association of slow- and fast-alpha bands with the planning and preparation of SEM, and the specific role of these sub-bands for both, the attention network and the coordination and integration of sensory information with a (oculo)-motor response. Copyright © 2011 Elsevier B.V. All rights reserved.

Your actions in my cerebellum: subclinical deficits in action observation in patients with unilateral chronic cerebellar stroke.

PubMed

Cattaneo, Luigi; Fasanelli, Monica; Andreatta, Olaf; Bonifati, Domenico Marco; Barchiesi, Guido; Caruana, Fausto

2012-03-01

Empirical evidence indicates that cognitive consequences of cerebellar lesions tend to be mild and less important than the symptoms due to lesions to cerebral areas. By contrast, imaging studies consistently report strong cerebellar activity during tasks of action observation and action understanding. This has been interpreted as part of the automatic motor simulation process that takes place in the context of action observation. The function of the cerebellum as a sequencer during executed movements makes it a good candidate, within the framework of embodied cognition, for a pivotal role in understanding the timing of action sequences. Here, we investigated a cohort of eight patients with chronic, first-ever, isolated, ischemic lesions of the cerebellum. The experimental task consisted in identifying a plausible sequence of pictures from a randomly ordered group of still frames extracted from (a) a complex action performed by a human actor ("biological action" test) or (b) a complex physical event occurring to an inanimate object ("folk physics" test). A group of 16 healthy participants was used as control. The main result showed that cerebellar patients performed significantly worse than controls in both sequencing tasks, but performed much worse in the "biological action" test than in the "folk physics" test. The dissociation described here suggests that observed sequences of simple motor acts seem to be represented differentially from other sequences in the cerebellum.

Cognitive Enhancement or Cognitive Cost: Trait-Specific Outcomes of Brain Stimulation in the Case of Mathematics Anxiety

PubMed Central

Sarkar, Amar; Dowker, Ann

2014-01-01

The surge in noninvasive brain stimulation studies investigating cognitive enhancement has neglected the effect of interindividual differences, such as traits, on stimulation outcomes. Using the case of mathematics anxiety in a sample of healthy human participants in a placebo-controlled, double-blind, crossover experiment, we show that identical transcranial direct current stimulation (tDCS) exerts opposite behavioral and physiological effects depending on individual trait levels. Mathematics anxiety is the negative emotional response elicited by numerical tasks, impairing mathematical achievement. tDCS was applied to the dorsolateral prefrontal cortex, a frequent target for modulating emotional regulation. It improved reaction times on simple arithmetic decisions and decreased cortisol concentrations (a biomarker of stress) in high mathematics anxiety individuals. In contrast, tDCS impaired reaction times for low mathematics anxiety individuals and prevented a decrease in cortisol concentration compared with sham stimulation. Both groups showed a tDCS-induced side effect—impaired executive control in a flanker task—a cognitive function subserved by the stimulated region. These behavioral and physiological double dissociations have implications for brain stimulation research by highlighting the role of individual traits in experimental findings. Brain stimulation clearly does not produce uniform benefits, even applied in the same configuration during the same tasks, but may interact with traits to produce markedly opposed outcomes. PMID:25505313

Cognitive enhancement or cognitive cost: trait-specific outcomes of brain stimulation in the case of mathematics anxiety.

PubMed

Sarkar, Amar; Dowker, Ann; Cohen Kadosh, Roi

2014-12-10

The surge in noninvasive brain stimulation studies investigating cognitive enhancement has neglected the effect of interindividual differences, such as traits, on stimulation outcomes. Using the case of mathematics anxiety in a sample of healthy human participants in a placebo-controlled, double-blind, crossover experiment, we show that identical transcranial direct current stimulation (tDCS) exerts opposite behavioral and physiological effects depending on individual trait levels. Mathematics anxiety is the negative emotional response elicited by numerical tasks, impairing mathematical achievement. tDCS was applied to the dorsolateral prefrontal cortex, a frequent target for modulating emotional regulation. It improved reaction times on simple arithmetic decisions and decreased cortisol concentrations (a biomarker of stress) in high mathematics anxiety individuals. In contrast, tDCS impaired reaction times for low mathematics anxiety individuals and prevented a decrease in cortisol concentration compared with sham stimulation. Both groups showed a tDCS-induced side effect-impaired executive control in a flanker task-a cognitive function subserved by the stimulated region. These behavioral and physiological double dissociations have implications for brain stimulation research by highlighting the role of individual traits in experimental findings. Brain stimulation clearly does not produce uniform benefits, even applied in the same configuration during the same tasks, but may interact with traits to produce markedly opposed outcomes. Copyright © 2014 Sarkar et al.

Temporal Information Processing and its Relation to Executive Functions in Elderly Individuals.

PubMed

Nowak, Kamila; Dacewicz, Anna; Broczek, Katarzyna; Kupisz-Urbanska, Malgorzata; Galkowski, Tadeusz; Szelag, Elzbieta

2016-01-01

Normal aging triggers deterioration in cognitive functions. Evidence has shown that these age-related changes concern also executive functions (EF) as well as temporal information processing (TIP) in a millisecond range. A considerable amount of literature data has indicated that each of these two functions sets a frame for our mental activity and may be considered in terms of embodied cognition due to advanced age. The present study addresses the question whether in elderly subjects the efficiency of TIP is related to individual differences in EF. The study involved 53 normal healthy participants aged from 65 to 78. In these subjects TIP was assessed by sequencing abilities measured with temporal-order threshold (TOT). It is defined as the minimum time gap separating two auditory stimuli presented in rapid succession which is necessary for a subject to report correctly their temporal order, thus the relation 'before-after.' The EF were assessed with regard to the efficiency of the executive planning measured with the Tower of London-Drexel University (TOL DX ) which has become a well-known EF task. Using Spearman's rank correlations we observed two main results. Firstly, the indices of the TOL DX indicated a coherent construct reflecting the effectiveness of executive planning in the elderly. Initiation time seemed dissociated from these coherent indices, which suggested a specific strategy of mental planning in the elderly based on on-line planning rather than on preplanning. Secondly, TOT was significantly correlated with the indices of TOL DX . Although some of these correlations were modified by subject's age, the correlation between TOT and the main index of TOL DX ( 'Total Move Score' ) was rather age resistant. These results suggest that normal aging may be characterized by an overlapping of deteriorated TIP and deteriorated EF.

Temporal Information Processing and its Relation to Executive Functions in Elderly Individuals

PubMed Central

Nowak, Kamila; Dacewicz, Anna; Broczek, Katarzyna; Kupisz-Urbanska, Malgorzata; Galkowski, Tadeusz; Szelag, Elzbieta

2016-01-01

Normal aging triggers deterioration in cognitive functions. Evidence has shown that these age-related changes concern also executive functions (EF) as well as temporal information processing (TIP) in a millisecond range. A considerable amount of literature data has indicated that each of these two functions sets a frame for our mental activity and may be considered in terms of embodied cognition due to advanced age. The present study addresses the question whether in elderly subjects the efficiency of TIP is related to individual differences in EF. The study involved 53 normal healthy participants aged from 65 to 78. In these subjects TIP was assessed by sequencing abilities measured with temporal-order threshold (TOT). It is defined as the minimum time gap separating two auditory stimuli presented in rapid succession which is necessary for a subject to report correctly their temporal order, thus the relation ‘before-after.’ The EF were assessed with regard to the efficiency of the executive planning measured with the Tower of London-Drexel University (TOLDX) which has become a well-known EF task. Using Spearman’s rank correlations we observed two main results. Firstly, the indices of the TOLDX indicated a coherent construct reflecting the effectiveness of executive planning in the elderly. Initiation time seemed dissociated from these coherent indices, which suggested a specific strategy of mental planning in the elderly based on on-line planning rather than on preplanning. Secondly, TOT was significantly correlated with the indices of TOLDX. Although some of these correlations were modified by subject’s age, the correlation between TOT and the main index of TOLDX (‘Total Move Score’) was rather age resistant. These results suggest that normal aging may be characterized by an overlapping of deteriorated TIP and deteriorated EF. PMID:27807426

Model-based Executive Control through Reactive Planning for Autonomous Rovers

NASA Technical Reports Server (NTRS)

Finzi, Alberto; Ingrand, Felix; Muscettola, Nicola

2004-01-01

This paper reports on the design and implementation of a real-time executive for a mobile rover that uses a model-based, declarative approach. The control system is based on the Intelligent Distributed Execution Architecture (IDEA), an approach to planning and execution that provides a unified representational and computational framework for an autonomous agent. The basic hypothesis of IDEA is that a large control system can be structured as a collection of interacting agents, each with the same fundamental structure. We show that planning and real-time response are compatible if the executive minimizes the size of the planning problem. We detail the implementation of this approach on an exploration rover (Gromit an RWI ATRV Junior at NASA Ames) presenting different IDEA controllers of the same domain and comparing them with more classical approaches. We demonstrate that the approach is scalable to complex coordination of functional modules needed for autonomous navigation and exploration.

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.

Perseveration induces dissociative uncertainty in obsessive-compulsive disorder.

PubMed

Giele, Catharina L; van den Hout, Marcel A; Engelhard, Iris M; Dek, Eliane C P; Toffolo, Marieke B J; Cath, Danielle C

2016-09-01

Obsessive compulsive (OC)-like perseveration paradoxically increases feelings of uncertainty. We studied whether the underlying mechanism between perseveration and uncertainty is a reduced accessibility of meaning ('semantic satiation'). OCD patients (n = 24) and matched non-clinical controls (n = 24) repeated words 2 (non-perseveration) or 20 times (perseveration). They decided whether this word was related to another target word. Speed of relatedness judgments and feelings of dissociative uncertainty were measured. The effects of real-life perseveration on dissociative uncertainty were tested in a smaller subsample of the OCD group (n = 9). Speed of relatedness judgments was not affected by perseveration. However, both groups reported more dissociative uncertainty after perseveration compared to non-perseveration, which was higher in OCD patients. Patients reported more dissociative uncertainty after 'clinical' perseveration compared to non-perseveration.. Both parts of this study are limited by some methodological issues and a small sample size. Although the mechanism behind 'perseveration → uncertainty' is still unclear, results suggest that the effects of perseveration are counterproductive. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

Free energy landscape of dissociative adsorption of methane on ideal and defected graphene from ab initio simulations

NASA Astrophysics Data System (ADS)

Wlazło, M.; Majewski, J. A.

2018-03-01

We study the dissociative adsorption of methane at the surface of graphene. Free energy profiles, which include activation energies for different steps of the reaction, are computed from constrained ab initio molecular dynamics. At 300 K, the reaction barriers are much lower than experimental bond dissociation energies of gaseous methane, strongly indicating that the graphene surface acts as a catalyst of methane decomposition. On the other hand, the barriers are still much higher than on the nickel surface. Methane dissociation therefore occurs at a higher rate on nickel than on graphene. This reaction is a prerequisite for graphene growth from a precursor gas. Thus, the growth of the first monolayer should be a fast and efficient process while subsequent layers grow at a diminished rate and in a more controllable manner. Defects may also influence reaction energetics. This is evident from our results, in which simple defects (Stone-Wales defect and nitrogen substitution) lead to different free energy landscapes at both dissociation and adsorption steps of the process.

Simulations of dissociation constants in low pressure supercritical water

NASA Astrophysics Data System (ADS)

Halstead, S. J.; An, P.; Zhang, S.

2014-09-01

This article reports molecular dynamics simulations of the dissociation of hydrochloric acid and sodium hydroxide in water from ambient to supercritical temperatures at a fixed pressure of 250 atm. Corrosion of reaction vessels is known to be a serious problem of supercritical water, and acid/base dissociation can be a significant contributing factor to this. The SPC/e model was used in conjunction with solute models determined from density functional calculations and OPLSAA Lennard-Jones parameters. Radial distribution functions were calculated, and these show a significant increase in solute-solvent ordering upon forming the product ions at all temperatures. For both dissociations, rapidly decreasing entropy of reaction was found to be the controlling thermodynamic factor, and this is thought to arise due to the ions produced from dissociation maintaining a relatively high density and ordered solvation shell compared to the reactants. The change in entropy of reaction reaches a minimum at the critical temperature. The values of pKa and pKb were calculated and both increased with temperature, in qualitative agreement with other work, until a maximum value at 748 K, after which there was a slight decrease.

Method and System for Controlling a Dexterous Robot Execution Sequence Using State Classification

NASA Technical Reports Server (NTRS)

Sanders, Adam M. (Inventor); Quillin, Nathaniel (Inventor); Platt, Robert J., Jr. (Inventor); Pfeiffer, Joseph (Inventor); Permenter, Frank Noble (Inventor)

2014-01-01

A robotic system includes a dexterous robot and a controller. The robot includes a plurality of robotic joints, actuators for moving the joints, and sensors for measuring a characteristic of the joints, and for transmitting the characteristics as sensor signals. The controller receives the sensor signals, and is configured for executing instructions from memory, classifying the sensor signals into distinct classes via the state classification module, monitoring a system state of the robot using the classes, and controlling the robot in the execution of alternative work tasks based on the system state. A method for controlling the robot in the above system includes receiving the signals via the controller, classifying the signals using the state classification module, monitoring the present system state of the robot using the classes, and controlling the robot in the execution of alternative work tasks based on the present system state.

Open scapulothoracic dissociation.

PubMed

Fischer, P J; Kent, R B

2001-04-01

Scapulothoracic dissociation refers to the traumatic separation of the shoulder from the chest wall. This most commonly occurs as a closed injury. We present a case of open scapulothoracic dissociation and emphasize clinical features unique to this injury. In both closed and open scapulothoracic dissociation, the force necessary to shear the scapula from its thoracic attachments results in vascular disruption and neurologic injury to the upper extremity. As a consequence, patients have a pulseless, flail upper extremity with a significant chest wall hematoma (closed) or active bleeding (open). The first priority is to resuscitate and address life-threatening injuries. If the patient has active bleeding, immediate vascular control to prevent exsanguination is essential. Patients with ischemia and an incomplete injury or unreliable neurologic examination need revascularization. Outcome is based on the extent of brachial plexus or cervical nerve root avulsion. Patients with loss of neurologic function ultimately benefit from amputation at the appropriate level.

A dissociation between detection and identification of phobic stimuli: unconscious perception?

PubMed

Siegel, Paul; Han, Edward; Cohen, Don; Anderson, Jason

2013-01-01

A psychophysical paradigm for investigating unconscious perception was used to test the hypothesis of dissociation between detection and identification of phobic stimuli. Spider-phobic and non-phobic participants were presented with masked images of spiders and flowers and an equal number of control stimuli in a random sequence. After each masked stimulus was flashed, participants first reported whether or not an object was presented. Then they identified each stimulus as either a spider or a flower, regardless of their prior detection response. Phobic participants identified both detected and undetected spiders better than chance, as assessed by two measures of response bias. They did not exhibit dissociation between detection and identification for flowers. Non-phobic participants did not exhibit detection-identification dissociation for either spiders or flowers. These results are consistent with the interpretation that phobic individuals unconsciously perceive their feared stimulus, and constitute the first direct demonstration of such for emotional stimuli.

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.

Visualizing and Steering Dissociative Frustrated Double Ionization of Hydrogen Molecules

NASA Astrophysics Data System (ADS)

Zhang, Wenbin; Yu, Zuqing; Gong, Xiaochun; Wang, Junping; Lu, Peifen; Li, Hui; Song, Qiying; Ji, Qinying; Lin, Kang; Ma, Junyang; Li, Hanxiao; Sun, Fenghao; Qiang, Junjie; Zeng, Heping; He, Feng; Wu, Jian

2017-12-01

We experimentally visualize the dissociative frustrated double ionization of hydrogen molecules by using few-cycle laser pulses in a pump-probe scheme, in which process the tunneling ionized electron is recaptured by one of the outgoing nuclei of the breaking molecule. Three internuclear distances are recognized to enhance the dissociative frustrated double ionization of molecules at different instants after the first ionization step. The recapture of the electron can be further steered to one of the outgoing nuclei as desired by using phase-controlled two-color laser pulses. Both the experimental measurements and numerical simulations suggest that the Rydberg atom is favored to emit to the direction of the maximum of the asymmetric optical field. Our results on the one hand intuitively visualize the dissociative frustrated double ionization of molecules, and on the other hand open the possibility to selectively excite the heavy fragment ejected from a molecule.

Assessment of executive functions in patients with obsessive compulsive disorder by NeuroVR.

PubMed

La Paglia, Filippo; La Cascia, Caterina; Rizzo, Rosalinda; Riva, Giuseppe; La Barbera, Daniele

2012-01-01

Executive functions are often impaired in obsessive-compulsive disorder (OCD). We used a Virtual Reality version of the Multiple Errand Test (VMET) - developed dusing the free NeuroVR software (http://www.neurovr.org) - to evaluate the executive functions in daily life in 10 OCD patients and 10 controls. It is performed in a shopping setting where there are items to be bought and information to be obtained. The execution time for the whole task was higher in patients with OCD compared to controls, suggesting that patients with OCD need more time in planning than controls. The same difference was found in the partial errors during the task. Furthermore, the mean rank for and for interpretation failures is higher for controls, while the values of divided attention and the of self correction seems to be lower in controls. We think that obsessive patients tend to work with greater diligence and observance of rules than controls. In conclusion, these results provide initial support for the feasibility of VMET as assessment tool of executive functions. Specifically, the significant correlation found between the VMET and the neuropsychological battery support the ecological validity of VMET as an instrument for the evaluation of executive functions in patients with OCD.

Reward and punishment sensitivity and alcohol use: the moderating role of executive control.

PubMed

Jonker, Nienke C; Ostafin, Brian D; Glashouwer, Klaske A; van Hemel-Ruiter, Madelon E; de Jong, Peter J

2014-05-01

Reward sensitivity and to a lesser extent punishment sensitivity have been found to explain individual differences in alcohol use. Furthermore, many studies showed that addictive behaviors are characterized by impaired self-regulatory processes, and that individual differences related to alcohol use are moderated by executive control. This is the first study that explores the potential moderating role of executive control in the relation between reward and punishment sensitivity and alcohol use. Participants were 76 university students, selected on earlier given information about their alcohol use. Half of the participants indicated to drink little alcohol and half indicated to drink substantial amounts of alcohol. As expected, correlational analyses showed a positive relationship between reward sensitivity and alcohol use and a negative relation between punishment sensitivity and alcohol use. Regression analysis confirmed that reward sensitivity was a significant independent predictor of alcohol use. Executive control moderated the relation between punishment sensitivity and alcohol use, but not the relation between reward sensitivity and alcohol use. Only in individuals with weak executive control punishment sensitivity and alcohol use were negatively related. The results suggest that for individuals with weak executive control, punishment sensitivity might be a protective factor working against substantial alcohol use. Copyright © 2013 Elsevier Ltd. All rights reserved.

Interidentity amnesia for neutral, episodic information in dissociative identity disorder.

PubMed

Huntjens, Rafaële J C; Postma, Albert; Peters, Madelon L; Woertman, Liesbeth; van der Hart, Onno

2003-05-01

Interidentity amnesia is considered a hallmark of dissociative identity disorder (DID) in clinical practice. In this study, objective methods of testing episodic memory transfer between identities were used. Tests of both recall (interference paradigm) and recognition were used. A sample of 31 DID patients was included. Additionally, 50 control subjects participated, half functioning as normal controls and the other half simulating interidentity amnesia. Twenty-one patients subjectively reported complete one-way amnesia for the learning episode. However, objectively, neither recall nor recognition scores of patients were different from those of normal controls. It is suggested that clinical models of amnesia in DID may be specified to exclude episodic memory impairments for emotionally neutral material.

Dissociative symptoms are associated with reduced neuropsychological performance in patients with recurrent depression and a history of trauma exposure

PubMed Central

Frewen, Paul A.; Oremus, Carolina; Lanius, Ruth A.; McKinnon, Margaret C.

2016-01-01

Background Although preliminary work suggests that dissociative symptoms may impact neuropsychological performance in trauma-exposed populations, the relation between dissociation and cognitive performance has not been explored in patients with depression. Objective The present study examined dissociative symptoms in relation to neuropsychological performance in participants with a primary diagnosis of recurrent major depressive disorder (MDD) and a history of trauma exposure. Method Twenty-three participants with MDD and 20 healthy controls who did not differ in age, sex, education, or IQ were assessed. In addition to a standardized neuropsychological battery assessing frontotemporally mediated cognitive processes, participants completed clinical measures assessing dissociative symptoms, illness severity, and past history of trauma exposure. Results Among participants with MDD, greater severity of derealization was associated with reduced performance on measures of delayed visuospatial recall and recognition on a task of verbal memory recognition. In addition, more severe depersonalization was associated with slower processing speed and a response style lending itself toward better performance in a less active environment. Conclusions These findings point toward dissociative symptoms as a transdiagnostic factor associated with neuropsychological dysfunction in patients with depression and a history of trauma. Limitations and recommendations for future research are discussed. PMID:26927902

The role of executive functions in social impairment in Autism Spectrum Disorder.

PubMed

Leung, Rachel C; Vogan, Vanessa M; Powell, Tamara L; Anagnostou, Evdokia; Taylor, Margot J

2016-01-01

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by socio-communicative impairments. Executive dysfunction may explain some key characteristics of ASD, both social and nonsocial hallmarks. Limited research exists exploring the relations between executive function and social impairment in ASD and few studies have used a comparison control group. Thus, the objective of the present study was to investigate the relations between executive functioning using the Behavioral Rating Inventory of Executive Functioning (BRIEF), social impairment as measured by the Social Responsiveness Scale (SRS), and overall autistic symptomology as measured by the Autism Diagnostic Observation Schedule (ADOS) in children and adolescents with and without ASD. Seventy children and adolescents diagnosed with ASD and 71 typically developing controls were included in this study. Findings showed that behavioral regulation executive processes (i.e., inhibition, shifting, and emotional control) predicted social function in all children. However, metacognitive executive processes (i.e., initiation, working memory, planning, organization, and monitoring) predicted social function only in children with ASD and not in typically developing children. Our findings suggest a distinct metacognitive executive function-social symptom link in ASD that is not present in the typical population. Understanding components of executive functioning that contribute to the autistic symptomology, particularly in the socio-communicative domain, is crucial for developing effective interventions that target key executive processes as well as underlying behavioral symptoms.

Executive control over unconscious cognition: attentional sensitization of unconscious information processing

PubMed Central

Kiefer, Markus

2012-01-01

Unconscious priming is a prototypical example of an automatic process, which is initiated without deliberate intention. Classical theories of automaticity assume that such unconscious automatic processes occur in a purely bottom-up driven fashion independent of executive control mechanisms. In contrast to these classical theories, our attentional sensitization model of unconscious information processing proposes that unconscious processing is susceptible to executive control and is only elicited if the cognitive system is configured accordingly. It is assumed that unconscious processing depends on attentional amplification of task-congruent processing pathways as a function of task sets. This article provides an overview of the latest research on executive control influences on unconscious information processing. I introduce refined theories of automaticity with a particular focus on the attentional sensitization model of unconscious cognition which is specifically developed to account for various attentional influences on different types of unconscious information processing. In support of the attentional sensitization model, empirical evidence is reviewed demonstrating executive control influences on unconscious cognition in the domains of visuo-motor and semantic processing: subliminal priming depends on attentional resources, is susceptible to stimulus expectations and is influenced by action intentions and task sets. This suggests that even unconscious processing is flexible and context-dependent as a function of higher-level executive control settings. I discuss that the assumption of attentional sensitization of unconscious information processing can accommodate conflicting findings regarding the automaticity of processes in many areas of cognition and emotion. This theoretical view has the potential to stimulate future research on executive control of unconscious processing in healthy and clinical populations. PMID:22470329

Executive control over unconscious cognition: attentional sensitization of unconscious information processing.

PubMed

Kiefer, Markus

2012-01-01

Unconscious priming is a prototypical example of an automatic process, which is initiated without deliberate intention. Classical theories of automaticity assume that such unconscious automatic processes occur in a purely bottom-up driven fashion independent of executive control mechanisms. In contrast to these classical theories, our attentional sensitization model of unconscious information processing proposes that unconscious processing is susceptible to executive control and is only elicited if the cognitive system is configured accordingly. It is assumed that unconscious processing depends on attentional amplification of task-congruent processing pathways as a function of task sets. This article provides an overview of the latest research on executive control influences on unconscious information processing. I introduce refined theories of automaticity with a particular focus on the attentional sensitization model of unconscious cognition which is specifically developed to account for various attentional influences on different types of unconscious information processing. In support of the attentional sensitization model, empirical evidence is reviewed demonstrating executive control influences on unconscious cognition in the domains of visuo-motor and semantic processing: subliminal priming depends on attentional resources, is susceptible to stimulus expectations and is influenced by action intentions and task sets. This suggests that even unconscious processing is flexible and context-dependent as a function of higher-level executive control settings. I discuss that the assumption of attentional sensitization of unconscious information processing can accommodate conflicting findings regarding the automaticity of processes in many areas of cognition and emotion. This theoretical view has the potential to stimulate future research on executive control of unconscious processing in healthy and clinical populations.

Washing away your sins will set your mind free: physical cleansing modulates the effect of threatened morality on executive control.

PubMed

Kalanthroff, Eyal; Aslan, Chen; Dar, Reuven

2017-01-01

The effect of threatened morality on negative emotions and on altruistic behaviour has been shown to diminish following physical cleansing (hand-washing). We hypothesised that threatened morality will broadly impair the executive control system, and that physical cleansing will moderate this detrimental effect. Thirty-seven participants were asked to write about an immoral deed they had committed, whereupon half of them were allowed to wipe their hands. Three executive control tasks-Stroop, stop-signal, and object interference-were then administered to all participants. Participants who had not wiped their hands, but not those who did, demonstrated impaired performance, compared to hand-washing controls, in all three tasks. We conclude that threatened morality has a detrimental effect on executive control, specifically on conflict monitoring and response inhibition, and that physical cleansing "frees" this system, counteracting the detrimental effects of morality threats. We discuss possible implications for obsessive-compulsive disorder, which is characterised by deficient executive control and in which both threatened morality and physical cleansing are central concerns.

Executive control of stimulus-driven and goal-directed attention in visual working memory.

PubMed

Hu, Yanmei; Allen, Richard J; Baddeley, Alan D; Hitch, Graham J

2016-10-01

We examined the role of executive control in stimulus-driven and goal-directed attention in visual working memory using probed recall of a series of objects, a task that allows study of the dynamics of storage through analysis of serial position data. Experiment 1 examined whether executive control underlies goal-directed prioritization of certain items within the sequence. Instructing participants to prioritize either the first or final item resulted in improved recall for these items, and an increase in concurrent task difficulty reduced or abolished these gains, consistent with their dependence on executive control. Experiment 2 examined whether executive control is also involved in the disruption caused by a post-series visual distractor (suffix). A demanding concurrent task disrupted memory for all items except the most recent, whereas a suffix disrupted only the most recent items. There was no interaction when concurrent load and suffix were combined, suggesting that deploying selective attention to ignore the distractor did not draw upon executive resources. A final experiment replicated the independent interfering effects of suffix and concurrent load while ruling out possible artifacts. We discuss the results in terms of a domain-general episodic buffer in which information is retained in a transient, limited capacity privileged state, influenced by both stimulus-driven and goal-directed processes. The privileged state contains the most recent environmental input together with goal-relevant representations being actively maintained using executive resources.

Attentional Control and Subjective Executive Function in Treatment-Naive Adults with Attention Deficit Hyperactivity Disorder

PubMed Central

Grane, Venke Arntsberg; Endestad, Tor; Pinto, Arnfrid Farbu; Solbakk, Anne-Kristin

2014-01-01

We investigated performance-derived measures of executive control, and their relationship with self- and informant reported executive functions in everyday life, in treatment-naive adults with newly diagnosed Attention Deficit Hyperactivity Disorder (ADHD; n = 36) and in healthy controls (n = 35). Sustained attentional control and response inhibition were examined with the Test of Variables of Attention (T.O.V.A.). Delayed responses, increased reaction time variability, and higher omission error rate to Go signals in ADHD patients relative to controls indicated fluctuating levels of attention in the patients. Furthermore, an increment in NoGo commission errors when Go stimuli increased relative to NoGo stimuli suggests reduced inhibition of task-irrelevant stimuli in conditions demanding frequent responding. The ADHD group reported significantly more cognitive and behavioral executive problems than the control group on the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A). There were overall not strong associations between task performance and ratings of everyday executive function. However, for the ADHD group, T.O.V.A. omission errors predicted self-reported difficulties on the Organization of Materials scale, and commission errors predicted informant reported difficulties on the same scale. Although ADHD patients endorsed more symptoms of depression and anxiety on the Achenbach System of Empirically Based Assessment (ASEBA) than controls, ASEBA scores were not significantly associated with T.O.V.A. performance scores. Altogether, the results indicate multifaceted alteration of attentional control in adult ADHD, and accompanying subjective difficulties with several aspects of executive function in everyday living. The relationships between the two sets of data were modest, indicating that the measures represent non-redundant features of adult ADHD. PMID:25545156

Attentional control and subjective executive function in treatment-naive adults with Attention Deficit Hyperactivity Disorder.

PubMed

Grane, Venke Arntsberg; Endestad, Tor; Pinto, Arnfrid Farbu; Solbakk, Anne-Kristin

2014-01-01

We investigated performance-derived measures of executive control, and their relationship with self- and informant reported executive functions in everyday life, in treatment-naive adults with newly diagnosed Attention Deficit Hyperactivity Disorder (ADHD; n = 36) and in healthy controls (n = 35). Sustained attentional control and response inhibition were examined with the Test of Variables of Attention (T.O.V.A.). Delayed responses, increased reaction time variability, and higher omission error rate to Go signals in ADHD patients relative to controls indicated fluctuating levels of attention in the patients. Furthermore, an increment in NoGo commission errors when Go stimuli increased relative to NoGo stimuli suggests reduced inhibition of task-irrelevant stimuli in conditions demanding frequent responding. The ADHD group reported significantly more cognitive and behavioral executive problems than the control group on the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A). There were overall not strong associations between task performance and ratings of everyday executive function. However, for the ADHD group, T.O.V.A. omission errors predicted self-reported difficulties on the Organization of Materials scale, and commission errors predicted informant reported difficulties on the same scale. Although ADHD patients endorsed more symptoms of depression and anxiety on the Achenbach System of Empirically Based Assessment (ASEBA) than controls, ASEBA scores were not significantly associated with T.O.V.A. performance scores. Altogether, the results indicate multifaceted alteration of attentional control in adult ADHD, and accompanying subjective difficulties with several aspects of executive function in everyday living. The relationships between the two sets of data were modest, indicating that the measures represent non-redundant features of adult ADHD.

CO2 Dissociation by Low Current Gliding Discharge in the Reverse Vortex Flow

NASA Astrophysics Data System (ADS)

Gutsol, Alexander

2012-10-01

If performed with high energy efficiency, plasma-chemical dissociation of carbon dioxide can be a way of converting and storing energy when there is an excess of electric energy, for example generated by solar elements of wind turbines. CO2 dissociation with efficiency of up to 90% was reported earlier for low pressure microwave discharge in supersonic flow. A new plasma-chemical system uses a low current gliding discharge in the reverse vortex flow of plasma gas. The system is a development of the Gliding Arc in Tornado reactor. The system was used to study dissociation of CO2 in wide ranges of the following experimental parameters: reactor pressure (15-150 kPa), discharge current (50-500 mA), gas flow rate (3-30 liters per minute), and electrode gap length (1-10 cm). Additionally, the effect of thermal energy recuperation on CO2 dissociation efficiency was tested. Plasma chemical efficiency of CO2 dissociation is very low (about 3%) in a short discharge at low pressures (about 15 kPa) when it is defined by electronic excitation. The highest efficiency (above 40%) was reached at pressures 50-70 kPa in a long discharge with thermal energy recuperation. It means that the process is controlled by thermal dissociation with subsequent effective quenching. Plasma chemical efficiency was determined from the data of chromatographic analysis and oscilloscope electric power integration, and also was checked calorimetrically by the thermal balance of the system.

OCILOW-Wheeled Platform Controls Executable Set

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

Jansen, John F.

2005-11-30

The OCILOW Controls Executable Set is the complete set of machine executable instructions to control the motion of wheeled platforms that incorporate Off-Centered In-Line Omni-directional Wheels (OCILOW). The controls utilize command signals for the desired motion of the platform (X, Y and Theta) and calculate and control the steering and rolling motion required of each OCILOW wheels to achieve the desired translational and rotational platform motion. The controls utilize signals from the wheel steering and rolling resolvers, and from three load cells located at each wheels, to coordinate the motion of all wheels, while respecting their non-holonomic constraints (i.e., keepingmore » internal stresses and slippage due to possible errors, uneven floors, bumps, misalignment, etc. bounded). The OCILOW Controls Executable Set, which is copyrighted here, is an embodiment of the generic OCILOW algorithms (patented separately) developed specifically for controls of the Proof-of-Principle-Transporter (POP-T) system that has been developed to demonstrate the overall OCILOW controls feasibility and capabilities.« less

Quantum optimal control of isomerization dynamics of a one-dimensional reaction-path model dominated by a competing dissociation channel

NASA Astrophysics Data System (ADS)

Kurosaki, Yuzuru; Artamonov, Maxim; Ho, Tak-San; Rabitz, Herschel

2009-07-01

Quantum wave packet optimal control simulations with intense laser pulses have been carried out for studying molecular isomerization dynamics of a one-dimensional (1D) reaction-path model involving a dominant competing dissociation channel. The 1D intrinsic reaction coordinate model mimics the ozone open→cyclic ring isomerization along the minimum energy path that successively connects the ozone cyclic ring minimum, the transition state (TS), the open (global) minimum, and the dissociative O2+O asymptote on the O3 ground-state A1' potential energy surface. Energetically, the cyclic ring isomer, the TS barrier, and the O2+O dissociation channel lie at ˜0.05, ˜0.086, and ˜0.037 hartree above the open isomer, respectively. The molecular orientation of the modeled ozone is held constant with respect to the laser-field polarization and several optimal fields are found that all produce nearly perfect isomerization. The optimal control fields are characterized by distinctive high temporal peaks as well as low frequency components, thereby enabling abrupt transfer of the time-dependent wave packet over the TS from the open minimum to the targeted ring minimum. The quick transition of the ozone wave packet avoids detrimental leakage into the competing O2+O channel. It is possible to obtain weaker optimal laser fields, resulting in slower transfer of the wave packets over the TS, when a reduced level of isomerization is satisfactory.

The contribution of executive control to semantic cognition: Convergent evidence from semantic aphasia and executive dysfunction.

PubMed

Thompson, Hannah E; Almaghyuli, Azizah; Noonan, Krist A; Barak, Ohr; Lambon Ralph, Matthew A; Jefferies, Elizabeth

2018-01-03

Semantic cognition, as described by the controlled semantic cognition (CSC) framework (Rogers et al., , Neuropsychologia, 76, 220), involves two key components: activation of coherent, generalizable concepts within a heteromodal 'hub' in combination with modality-specific features (spokes), and a constraining mechanism that manipulates and gates this knowledge to generate time- and task-appropriate behaviour. Executive-semantic goal representations, largely supported by executive regions such as frontal and parietal cortex, are thought to allow the generation of non-dominant aspects of knowledge when these are appropriate for the task or context. Semantic aphasia (SA) patients have executive-semantic deficits, and these are correlated with general executive impairment. If the CSC proposal is correct, patients with executive impairment should not only exhibit impaired semantic cognition, but should also show characteristics that align with those observed in SA. This possibility remains largely untested, as patients selected on the basis that they show executive impairment (i.e., with 'dysexecutive syndrome') have not been extensively tested on tasks tapping semantic control and have not been previously compared with SA cases. We explored conceptual processing in 12 patients showing symptoms consistent with dysexecutive syndrome (DYS) and 24 SA patients, using a range of multimodal semantic assessments which manipulated control demands. Patients with executive impairments, despite not being selected to show semantic impairments, nevertheless showed parallel patterns to SA cases. They showed strong effects of distractor strength, cues and miscues, and probe-target distance, plus minimal effects of word frequency on comprehension (unlike semantic dementia patients with degradation of conceptual knowledge). This supports a component process account of semantic cognition in which retrieval is shaped by control processes, and confirms that deficits in SA patients reflect difficulty controlling semantic retrieval. © 2018 The Authors. Journal of Neuropsychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

Automated procedure execution for space vehicle autonomous control

NASA Technical Reports Server (NTRS)

Broten, Thomas A.; Brown, David A.

1990-01-01

Increased operational autonomy and reduced operating costs have become critical design objectives in next-generation NASA and DoD space programs. The objective is to develop a semi-automated system for intelligent spacecraft operations support. The Spacecraft Operations and Anomaly Resolution System (SOARS) is presented as a standardized, model-based architecture for performing High-Level Tasking, Status Monitoring and automated Procedure Execution Control for a variety of spacecraft. The particular focus is on the Procedure Execution Control module. A hierarchical procedure network is proposed as the fundamental means for specifying and representing arbitrary operational procedures. A separate procedure interpreter controls automatic execution of the procedure, taking into account the current status of the spacecraft as maintained in an object-oriented spacecraft model.

HYDRATE v1.5 OPTION OF TOUGH+ v1.5

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

Moridis, George

HYDRATE v1.5 is a numerical code that for the simulation of the behavior of hydrate-bearing geologic systems, and represents the third update of the code since its first release [Moridis et al., 2008]. It is an option of TOUGH+ v1.5 [Moridis and Pruess, 2014], a successor to the TOUGH2 [Pruess et al., 1999, 2012] family of codes for multi-component, multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory. HYDRATE v1.5 needs the TOUGH+ v1.5 core code in order to compile and execute. It is written in standard FORTRAN 95/2003, and can be run on any computational platformmore » (workstation, PC, Macintosh) for which such compilers are available. By solving the coupled equations of mass and heat balance, the fully operational TOUGH+HYDRATE code can model the non-isothermal gas release, phase behavior and flow of fluids and heat under conditions typical of common natural CH 4-hydrate deposits (i.e., in the permafrost and in deep ocean sediments) in complex geological media at any scale (from laboratory to reservoir) at which Darcy's law is valid. TOUGH+HYDRATE v1.5 includes both an equilibrium and a kinetic model of hydrate formation and dissociation. The model accounts for heat and up to four mass components, i.e., water, CH 4, hydrate, and water-soluble inhibitors such as salts or alcohols. These are partitioned among four possible phases (gas phase, liquid phase, ice phase and hydrate phase). Hydrate dissociation or formation, phase changes and the corresponding thermal effects are fully described, as are the effects of inhibitors. The model can describe all possible hydrate dissociation mechanisms, i.e., depressurization, thermal stimulation, salting-out effects and inhibitor-induced effects.« less

Real-Life Impact of Executive Function Impairments in Adults Who Were Born Very Preterm.

PubMed

Kroll, Jasmin; Karolis, Vyacheslav; Brittain, Philip J; Tseng, Chieh-En Jane; Froudist-Walsh, Sean; Murray, Robin M; Nosarti, Chiara

2017-05-01

Children and adolescents who were born very preterm (≤32 weeks' gestation) are vulnerable to experiencing cognitive problems, including in executive function. However, it remains to be established whether cognitive deficits are evident in adulthood and whether these exert a significant effect on an individual's real-lifeachievement. Using a cross-sectional design, we tested a range of neurocognitive abilities, with a focus on executive function, in a sample of 122 very preterm individuals and 89 term-born controls born between 1979 and 1984. Associations between executive function and a range of achievement measures, indicative of a successful transition to adulthood, were examined. Very preterm adults performed worse compared to controls on measures of intellectual ability and executive function with moderate to large effect sizes. They also demonstrated significantly lower achievement levels in terms of years spent in education, employment status, and on a measure of functioning in work and social domains. Results of regression analysis indicated a stronger positive association between executive function and real-life achievement in the very preterm group compared to controls. Very preterm born adults demonstrate executive function impairments compared to full-term controls, and these are associated with lower achievement in several real-life domains. (JINS, 2017, 23, 381-389).

Superior colliculus resting state networks in post-traumatic stress disorder and its dissociative subtype.

PubMed

Olivé, Isadora; Densmore, Maria; Harricharan, Sherain; Théberge, Jean; McKinnon, Margaret C; Lanius, Ruth

2018-01-01

The innate alarm system (IAS) models the neurocircuitry involved in threat processing in posttraumatic stress disorder (PTSD). Here, we investigate a primary subcortical structure of the IAS model, the superior colliculus (SC), where the SC is thought to contribute to the mechanisms underlying threat-detection in PTSD. Critically, the functional connectivity between the SC and other nodes of the IAS remains unexplored. We conducted a resting-state fMRI study to investigate the functional architecture of the IAS, focusing on connectivity of the SC in PTSD (n = 67), its dissociative subtype (n = 41), and healthy controls (n = 50) using region-of-interest seed-based analysis. We observed group-specific resting state functional connectivity between the SC for both PTSD and its dissociative subtype, indicative of dedicated IAS collicular pathways in each group of patients. When comparing PTSD to its dissociative subtype, we observed increased resting state functional connectivity between the left SC and the right dorsolateral prefrontal cortex (DLPFC) in PTSD. The DLPFC is involved in modulation of emotional processes associated with active defensive responses characterising PTSD. Moreover, when comparing PTSD to its dissociative subtype, increased resting state functional connectivity was observed between the right SC and the right temporoparietal junction in the dissociative subtype. The temporoparietal junction is involved in depersonalization responses associated with passive defensive responses typical of the dissociative subtype. Our findings suggest that unique resting state functional connectivity of the SC parallels the unique symptom profile and defensive responses observed in PTSD and its dissociative subtype. Hum Brain Mapp 39:563-574, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Trauma-related dissociative (conversion) disorders in children and adolescents--an overview of assessment tools and treatment principles.

PubMed

Diseth, Trond H; Christie, Helen J

2005-01-01

A high proportion of patients in child and adolescent psychiatry with significant dissociative symptomatology after early childhood traumatization may go undiagnosed, be wrongly diagnosed and/or inappropriately treated. The diagnostics and treatment of dissociative disorders have been limited by lack of comprehensive, reliable and valid instruments and the ongoing polarization and fierce controversy regarding treatment. However, recent neurobiological findings of neurochemical, functional and structural cerebral consequences of early stressful childhood experiences point out a need for active, early and effective identification and treatment interventions. We present an update on assessment tools available in the Nordic countries, and an overview of different appropriate therapeutic intervention models for children and adolescents. A systematic overview of studies of dissociation in children and adolescent published over the last decade disclosed a total of 1019 references. The 465 papers describing aspects of assessment tools and/or treatment were studied in detail. Reliable and valid screening questionnaires and diagnostic interviews for children and adolescents now allow for effective early identification of dissociative disorders. A combination of individual psychotherapy, pharmacotherapy and family therapy are often required to handle dissociative disorders in children and adolescents. Cognitive-behavioural therapy, hypnotherapy, Eye-Movement Desensitization-Reprocessing (EMDR), psychodynamic therapy and an integrated approach are the main described psychotherapeutic approaches, but treatment of dissociation in children and adolescent does not require allegiance to any one particular treatment model. However, achievement of physical safety by providing a safe environment is a primary goal that supersedes any other therapeutic work. Assessments tools are now available, and appropriate therapeutic intervention models may hopefully contribute to reduce the risk of wrong diagnoses and inappropriate treatment of dissociative symptomatology in children and adolescents. However, controlled clinical trials of the various interventions and longitudinal outcome studies are needed.

Differential frontal-parietal phase synchrony during hypnosis as a function of hypnotic suggestibility.

PubMed

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

2011-10-01

Spontaneous dissociative alterations in awareness and perception among highly suggestible individuals following a hypnotic induction may result from disruptions in the functional coordination of the frontal-parietal network. We recorded EEG and self-reported state dissociation in control and hypnosis conditions in two sessions with low and highly suggestible participants. Highly suggestible participants reliably experienced greater state dissociation and exhibited lower frontal-parietal phase synchrony in the alpha2 frequency band during hypnosis than low suggestible participants. These findings suggest that highly suggestible individuals exhibit a disruption of the frontal-parietal network that is only observable following a hypnotic induction. Copyright © 2011 Society for Psychophysiological Research.

[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.

Training Theory of Mind and Executive Control: A Tool for Improving School Achievement?

ERIC Educational Resources Information Center

Kloo, Daniela; Perner, Josef

2008-01-01

In the preschool years, there are marked improvements in theory of mind (ToM) and executive functions. And, children's competence in these two core cognitive domains is associated with their academic achievement. Therefore, training ToM and executive control could be a valuable tool for improving children's success in school. This article reviews…

Executive Control Goes to School: Implications of Preschool Executive Performance for Observed Elementary Classroom Learning Engagement

ERIC Educational Resources Information Center

Nelson, Timothy D.; Nelson, Jennifer Mize; James, Tiffany D.; Clark, Caron A. C.; Kidwell, Katherine M.; Espy, Kimberly Andrews

2017-01-01

The transition to elementary school is accompanied by increasing demands for children to regulate their attention and behavior within the classroom setting. Executive control (EC) may be critical for meeting these demands; however, few studies have rigorously examined the association between EC and observed classroom behavior. This study examined…

Bayesian model reveals latent atrophy factors with dissociable cognitive trajectories in Alzheimer's disease.

PubMed

Zhang, Xiuming; Mormino, Elizabeth C; Sun, Nanbo; Sperling, Reisa A; Sabuncu, Mert R; Yeo, B T Thomas

2016-10-18

We used a data-driven Bayesian model to automatically identify distinct latent factors of overlapping atrophy patterns from voxelwise structural MRIs of late-onset Alzheimer's disease (AD) dementia patients. Our approach estimated the extent to which multiple distinct atrophy patterns were expressed within each participant rather than assuming that each participant expressed a single atrophy factor. The model revealed a temporal atrophy factor (medial temporal cortex, hippocampus, and amygdala), a subcortical atrophy factor (striatum, thalamus, and cerebellum), and a cortical atrophy factor (frontal, parietal, lateral temporal, and lateral occipital cortices). To explore the influence of each factor in early AD, atrophy factor compositions were inferred in beta-amyloid-positive (Aβ+) mild cognitively impaired (MCI) and cognitively normal (CN) participants. All three factors were associated with memory decline across the entire clinical spectrum, whereas the cortical factor was associated with executive function decline in Aβ+ MCI participants and AD dementia patients. Direct comparison between factors revealed that the temporal factor showed the strongest association with memory, whereas the cortical factor showed the strongest association with executive function. The subcortical factor was associated with the slowest decline for both memory and executive function compared with temporal and cortical factors. These results suggest that distinct patterns of atrophy influence decline across different cognitive domains. Quantification of this heterogeneity may enable the computation of individual-level predictions relevant for disease monitoring and customized therapies. Factor compositions of participants and code used in this article are publicly available for future research.

Unique insula subregion resting-state functional connectivity with amygdala complexes in posttraumatic stress disorder and its dissociative subtype.

PubMed

Nicholson, Andrew A; Sapru, Iman; Densmore, Maria; Frewen, Paul A; Neufeld, Richard W J; Théberge, Jean; McKinnon, Margaret C; Lanius, Ruth A

2016-04-30

The insula and amygdala are implicated in the pathophysiology of posttraumatic stress disorder (PTSD), where both have been shown to be hyper/hypoactive in non-dissociative (PTSD-DS) and dissociative subtype (PTSD+DS) PTSD patients, respectively, during symptom provocation. However, the functional connectivity between individual insula subregions and the amygdala has not been investigated in persons with PTSD, with or without the dissociative subtype. We examined insula subregion (anterior, mid, and posterior) functional connectivity with the bilateral amygdala using a region-of-interest seed-based approach via PickAtlas and SPM8. Resting-state fMRI was conducted with (n=61) PTSD patients (n=44 PTSD-DS; n=17 PTSD+DS), and (n=40) age-matched healthy controls. When compared to controls, the PTSD-DS group displayed increased insula connectivity (bilateral anterior, bilateral mid, and left posterior) to basolateral amygdala clusters in both hemispheres, and the PTSD+DS group displayed increased insula connectivity (bilateral anterior, left mid, and left posterior) to the left basolateral amygdala complex. Moreover, as compared to PTSD-DS, increased insula subregion connectivity (bilateral anterior, left mid, and right posterior) to the left basolateral amygdala was found in PTSD+DS. Depersonalization/derealization symptoms and PTSD symptom severity correlated with insula subregion connectivity to the basolateral amygdala within PTSD patients. This study is an important first step in elucidating patterns of neural connectivity associated with unique symptoms of arousal/interoception, emotional processing, and awareness of bodily states, in PTSD and its dissociative subtype. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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

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

Balancing Automatic-Controlled Behaviors and Emotional-Salience States: A Dynamic Executive Functioning Hypothesis.

PubMed

Kluwe-Schiavon, Bruno; Viola, Thiago W; Sanvicente-Vieira, Breno; Malloy-Diniz, Leandro F; Grassi-Oliveira, Rodrigo

2016-01-01

Recently, there has been growing interest in understanding how executive functions are conceptualized in psychopathology. Since several models have been proposed, the major issue lies within the definition of executive functioning itself. Theoretical discussions have emerged, narrowing the boundaries between "hot" and "cold" executive functions or between self-regulation and cognitive control. Nevertheless, the definition of executive functions is far from a consensual proposition and it has been suggested that these models might be outdated. Current efforts indicate that human behavior and cognition are by-products of many brain systems operating and interacting at different levels, and therefore, it is very simplistic to assume a dualistic perspective of information processing. Based upon an adaptive perspective, we discuss how executive functions could emerge from the ability to solve immediate problems and to generalize successful strategies, as well as from the ability to synthesize and to classify environmental information in order to predict context and future. We present an executive functioning perspective that emerges from the dynamic balance between automatic-controlled behaviors and an emotional-salience state. According to our perspective, the adaptive role of executive functioning is to automatize efficient solutions simultaneously with cognitive demand, enabling individuals to engage such processes with increasingly complex problems. Understanding executive functioning as a mediator of stress and cognitive engagement not only fosters discussions concerning individual differences, but also offers an important paradigm to understand executive functioning as a continuum process rather than a categorical and multicomponent structure.

Balancing Automatic-Controlled Behaviors and Emotional-Salience States: A Dynamic Executive Functioning Hypothesis

PubMed Central

Kluwe-Schiavon, Bruno; Viola, Thiago W.; Sanvicente-Vieira, Breno; Malloy-Diniz, Leandro F.; Grassi-Oliveira, Rodrigo

2017-01-01

Recently, there has been growing interest in understanding how executive functions are conceptualized in psychopathology. Since several models have been proposed, the major issue lies within the definition of executive functioning itself. Theoretical discussions have emerged, narrowing the boundaries between “hot” and “cold” executive functions or between self-regulation and cognitive control. Nevertheless, the definition of executive functions is far from a consensual proposition and it has been suggested that these models might be outdated. Current efforts indicate that human behavior and cognition are by-products of many brain systems operating and interacting at different levels, and therefore, it is very simplistic to assume a dualistic perspective of information processing. Based upon an adaptive perspective, we discuss how executive functions could emerge from the ability to solve immediate problems and to generalize successful strategies, as well as from the ability to synthesize and to classify environmental information in order to predict context and future. We present an executive functioning perspective that emerges from the dynamic balance between automatic-controlled behaviors and an emotional-salience state. According to our perspective, the adaptive role of executive functioning is to automatize efficient solutions simultaneously with cognitive demand, enabling individuals to engage such processes with increasingly complex problems. Understanding executive functioning as a mediator of stress and cognitive engagement not only fosters discussions concerning individual differences, but also offers an important paradigm to understand executive functioning as a continuum process rather than a categorical and multicomponent structure. PMID:28154541

Rehabilitation of Executive Functions in Patients with Chronic Acquired Brain Injury with Goal Management Training, External Cuing, and Emotional Regulation: A Randomized Controlled Trial.

PubMed

Tornås, Sveinung; Løvstad, Marianne; Solbakk, Anne-Kristin; Evans, Jonathan; Endestad, Tor; Hol, Per Kristian; Schanke, Anne-Kristine; Stubberud, Jan

2016-04-01

Executive dysfunction is a common consequence of acquired brain injury (ABI), causing significant disability in daily life. This randomized controlled trial investigated the efficacy of Goal Management Training (GMT) in improving executive functioning in patients with chronic ABI. Seventy patients with a verified ABI and executive dysfunction were randomly allocated to GMT (n=33) or a psycho-educative active control condition, Brain Health Workshop (BHW) (n=37). In addition, all participants received external cueing by text messages. Neuropsychological tests and self-reported questionnaires of executive functioning were administered pre-intervention, immediately after intervention, and at 6 months follow-up. Assessors were blinded to group allocation. Questionnaire measures indicated significant improvement of everyday executive functioning in the GMT group, with effects lasting at least 6 months post-treatment. Both groups improved on the majority of the applied neuropsychological tests. However, improved performance on tests demanding executive attention was most prominent in the GMT group. The results indicate that GMT combined with external cueing is an effective metacognitive strategy training method, ameliorating executive dysfunction in daily life for patients with chronic ABI. The strongest effects were seen on self-report measures of executive functions 6 months post-treatment, suggesting that strategies learned in GMT were applied and consolidated in everyday life after the end of training. Furthermore, these findings show that executive dysfunction can be improved years after the ABI.

Acute effects of donepezil in healthy young adults underline the fractionation of executive functioning.

PubMed

Ginani, G E; Tufik, S; Bueno, O F A; Pradella-Hallinan, M; Rusted, J; Pompéia, S

2011-11-01

The cholinergic system is involved in the modulation of both bottom-up and top-down attentional control. Top-down attention engages multiple executive control processes, but few studies have investigated whether all or selective elements of executive functions are modulated by the cholinergic system. To investigate the acute effects of the pro-cholinergic donepezil in young, healthy volunteers on distinct components of executive functions we conducted a double-blind, placebo-controlled, independent-groups design study including 42 young healthy male participants who were randomly assigned to one of three oral treatments: glucose (placebo), donepezil 5 mg or donepezil 7.5 mg. The test battery included measures of different executive components (shifting, updating, inhibition, dual-task performance, planning, access to long-term memory), tasks that evaluated arousal/vigilance/visuomotor performance, as well as functioning of working memory subsidiary systems. Donepezil improved sustained attention, reaction times, dual-task performance and the executive component of digit span. The positive effects in these executive tasks did not correlate with arousal/visuomotor/vigilance measures. Among the various executive domains investigated donepezil selectively increased dual-task performance in a manner that could not be ascribed to improvement in arousal/vigilance/visuomotor performance nor working memory slave systems. Other executive tasks that rely heavily on visuospatial processing may also be modulated by the cholinergic system.

Drug-sensing hydrogels for the inducible release of biopharmaceuticals

NASA Astrophysics Data System (ADS)

Ehrbar, Martin; Schoenmakers, Ronald; Christen, Erik H.; Fussenegger, Martin; Weber, Wilfried

2008-10-01

Drug-dependent dissociation or association of cellular receptors represents a potent pharmacologic mode of action for regulating cell fate and function. Transferring the knowledge of pharmacologically triggered protein-protein interactions to materials science will enable novel design concepts for stimuli-sensing smart hydrogels. Here, we show the design and validation of an antibiotic-sensing hydrogel for the trigger-inducible release of human vascular endothelial growth factor. Genetically engineered bacterial gyrase subunit B (GyrB) (ref. 4) coupled to polyacrylamide was dimerized by the addition of the aminocoumarin antibiotic coumermycin, resulting in hydrogel formation. Addition of increasing concentrations of clinically validated novobiocin (Albamycin) dissociated the GyrB subunits, thereby resulting in dissociation of the hydrogel and dose- and time-dependent liberation of the entrapped protein pharmaceutical VEGF121 for triggering proliferation of human umbilical vein endothelial cells. Pharmacologically controlled hydrogels have the potential to fulfil the promises of stimuli-sensing materials as smart devices for spatiotemporally controlled delivery of drugs within the patient.

Coherent control at its most fundamental: carrier-envelope-phase-dependent electron localization in photodissociation of a H2(+) molecular ion beam target.

PubMed

Rathje, T; Sayler, A M; Zeng, S; Wustelt, P; Figger, H; Esry, B D; Paulus, G G

2013-08-30

Measurements and calculations of the absolute carrier-envelope-phase (CEP) effects in the photodissociation of the simplest molecule, H2(+), with a 4.5-fs Ti:sapphire laser pulse at intensities up to (4±2)×10(14)  W/cm2 are presented. Localization of the electron with respect to the two nuclei (during the dissociation process) is controlled via the CEP of the ultrashort laser pulses. In contrast to previous CEP-dependent experiments with neutral molecules, the dissociation of the molecular ions is not preceded by a photoionization process, which strongly influences the CEP dependence. Kinematically complete data are obtained by time- and position-resolved coincidence detection. The phase dependence is determined by a single-shot phase measurement correlated to the detection of the dissociation fragments. The experimental results show quantitative agreement with ab initio 3D time-dependent Schrödinger equation calculations that include nuclear vibration and rotation.

Can training in a real-time strategy video game attenuate cognitive decline in older adults?

PubMed

Basak, Chandramallika; Boot, Walter R; Voss, Michelle W; Kramer, Arthur F

2008-12-01

Declines in various cognitive abilities, particularly executive control functions, are observed in older adults. An important goal of cognitive training is to slow or reverse these age-related declines. However, opinion is divided in the literature regarding whether cognitive training can engender transfer to a variety of cognitive skills in older adults. In the current study, the authors trained older adults in a real-time strategy video game for 23.5 hr in an effort to improve their executive functions. A battery of cognitive tasks, including tasks of executive control and visuospatial skills, were assessed before, during, and after video-game training. The trainees improved significantly in the measures of game performance. They also improved significantly more than the control participants in executive control functions, such as task switching, working memory, visual short-term memory, and reasoning. Individual differences in changes in game performance were correlated with improvements in task switching. The study has implications for the enhancement of executive control processes of older adults. Copyright (c) 2009 APA, all rights reserved.

Attentional impairments in Huntington's disease: A specific deficit for the executive conflict.

PubMed

Maurage, Pierre; Heeren, Alexandre; Lahaye, Magali; Jeanjean, Anne; Guettat, Lamia; Verellen-Dumoulin, Christine; Halkin, Stéphane; Billieux, Joël; Constant, Eric

2017-05-01

Huntington's disease (HD) is characterized by motor and cognitive impairments including memory, executive, and attentional functions. However, because earlier studies relied on multidetermined attentional tasks, uncertainty still abounds regarding the differential deficit across attentional subcomponents. Likewise, the evolution of these deficits during the successive stages of HD remains unclear. The present study simultaneously explored 3 distinct networks of attention (alerting, orienting, executive conflict) in preclinical and clinical HD. Thirty-eight HD patients (18 preclinical) and 38 matched healthy controls completed the attention network test, an integrated and theoretically grounded task assessing the integrity of 3 attentional networks. Preclinical HD was not characterized by any attentional deficit compared to controls. Conversely, clinical HD was associated with a differential deficit across the 3 attentional networks under investigation, showing preserved performance for alerting and orienting networks but massive and specific impairment for the executive conflict network. This indexes an impaired use of executive control to resolve the conflict between task-relevant stimuli and interfering task-irrelevant ones. Clinical HD does not lead to a global attentional deficit but rather to a specific impairment for the executive control of attention. Moreover, the absence of attentional deficits in preclinical HD suggests that these deficits are absent at the initial stages of the disease. In view of their impact on everyday life, attentional deficits should be considered in clinical contexts. Therapeutic programs improving the executive control of attention by neuropsychology and neuromodulation should be promoted. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

On the Evolutionary Origins of Executive Functions

ERIC Educational Resources Information Center

Ardila, Alfredo

2008-01-01

In this paper it is proposed that the prefrontal lobe participates in two closely related but different executive function abilities: (1) "metacognitive executive functions": problem solving, planning, concept formation, strategy development and implementation, controlling attention, working memory, and the like; that is, executive functions as…

The relationship between theory of mind and the executive functions: Evidence from patients with frontal lobe damage.

PubMed

Yeh, Zai-Ting; Tsai, Ming-Cheng; Tsai, Ming-Dar; Lo, Chiao-Yu; Wang, Kaw-Chen

2017-01-01

"Theory of mind" (ToM) refers to the ability to predict others' thoughts, intentions, beliefs, and feelings. Evidence from neuropsychology and functional imaging indicates that ToM is a domain-specific or modular architecture; however, research in development psychology has suggested that ToM is the full development of the executive functions in individuals. Therefore, the relationship between ToM and the executive functions needs to be clarified. Since the frontal lobe plays a critical role in the abilities of ToM and the executive functions, patients with frontal lobe damage were recruited for the present study. Assessments of ToM and the executive functions were performed on 23 patients with frontal lobe damage and 20 healthy controls. When controlling for the executive functions, significant differences between the patient and normal groups were found in the affective component of ToM, but not in the cognitive component. The present study suggests that in various social situations, executing ToM abilities requires logical reasoning processes provided by the executive functions. However, the reasoning processes of affective ToM are independent of executive functions.

Bilingualism and Musicianship Enhance Cognitive Control

PubMed Central

2016-01-01

Learning how to speak a second language (i.e., becoming a bilingual) and learning how to play a musical instrument (i.e., becoming a musician) are both thought to increase executive control through experience-dependent plasticity. However, evidence supporting this effect is mixed for bilingualism and limited for musicianship. In addition, the combined effects of bilingualism and musicianship on executive control are unknown. To determine whether bilingualism, musicianship, and combined bilingualism and musicianship improve executive control, we tested 219 young adults belonging to one of four groups (bilinguals, musicians, bilingual musicians, and controls) on a nonlinguistic, nonmusical, visual-spatial Simon task that measured the ability to ignore an irrelevant and misinformative cue. Results revealed that bilinguals, musicians, and bilingual musicians showed an enhanced ability to ignore a distracting cue relative to controls, with similar levels of superior performance among bilinguals, musicians, and bilingual musicians. These results indicate that bilingualism and musicianship improve executive control and have implications for educational and rehabilitation programs that use music and foreign language instruction to boost cognitive performance. PMID:26819764

Resisting attraction: Individual differences in executive control are associated with subject-verb agreement errors in production.

PubMed

Veenstra, Alma; Antoniou, Kyriakos; Katsos, Napoleon; Kissine, Mikhail

2018-04-19

We propose that attraction errors in agreement production (e.g., the key to the cabinets are missing) are related to two components of executive control: working memory and inhibitory control. We tested 138 children aged 10 to 12, an age when children are expected to produce high rates of errors. To increase the potential of individual variation in executive control skills, participants came from monolingual, bilingual, and bidialectal language backgrounds. Attraction errors were elicited with a picture description task in Dutch and executive control was measured with a digit span task, Corsi blocks task, switching task, and attentional networks task. Overall, higher rates of attraction errors were negatively associated with higher verbal working memory and, independently, with higher inhibitory control. To our knowledge, this is the first demonstration of the role of both working memory and inhibitory control in attraction errors in production. Implications for memory- and grammar-based models are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Lapses in Sustained Attention and Their Relation to Executive Control and Fluid Abilities: An Individual Differences Investigation

ERIC Educational Resources Information Center

Unsworth, Nash; Redick, Thomas S.; Lakey, Chad E.; Young, Diana L.

2010-01-01

A latent variable analysis was conducted to examine the nature of individual differences in lapses of attention and their relation to executive and fluid abilities. Participants performed a sustained attention task along with multiple measures of executive control and fluid abilities. Lapses of attention were indexed based on the slowest reaction…

Executive functions deficit in mild cognitive impairment.

PubMed

Traykov, Latchezar; Raoux, Nadine; Latour, Florence; Gallo, Livia; Hanon, Olivier; Baudic, Sophie; Bayle, Catherine; Wenisch, Emilie; Remy, Philippe; Rigaud, Anne-Sophie

2007-12-01

To investigate whether patients diagnosed with amnestic mild cognitive impairment (MCI) have also impairment in attention/executive functions, and therefore to clarify whether all subcomponents of executive control are equally affected in MCI. MCI refers to the transitional state between normal aging and dementia. Amnestic MCI is characterized by impaired episodic memory, although subtle impairment of executive functions has been noted on neuropsychologic tests. We investigated 20 MCI patients and 20 normal controls using episodic memory, attention/executive functions, language, and praxis tests. MCI patients had significantly lower scores on all measures of the Free and Cued Selective Reminding Test (P<0.05 to 0.01) than controls. Furthermore, MCI had a greater number of perseverations (P<0.01) on Modified Card Sorting Test and the lowest performance on the Stroop Test (P<0.02). Our findings showed impairment in episodic memory performance in MCI as compared with that of controls. In addition, MCI patients had problems with response inhibition, switching, and cognitive flexibility, which encompass various aspects of executive functions. This suggests that MCI may be identified by using a more detailed procedure for the assessment of cognitive decline than the evaluation of memory alone.

The semantic and episodic subcomponents of famous person knowledge: dissociation in healthy subjects.

PubMed

Piolino, Pascale; Lamidey, Virginie; Desgranges, Béatrice; Eustache, Francis

2007-01-01

Fifty-two subjects between ages 40 and 79 years were administered a questionnaire assessing their ability to recall semantic information about famous people from 4 different decades and to recollect its episodic source of acquisition together with autonoetic consciousness via the remember-know paradigm. In addition, they underwent a battery of standardized neuropsychological tests to assess episodic and semantic memory and executive functions. The analyses of age reveal differences for the episodic source score but no differences between age groups for the semantic scores within each decade. Regardless of the age of people, the analyses also show that semantic memory subcomponents of the famous person test are highly associated with each other as well as with the source component. The recall of semantic information on the famous person test relies on participants' semantic abilities, whereas the recall of its episodic source depends on their executive functions. The present findings confirm the existence of an episodic-semantic distinction in knowledge about famous people. They provide further evidence that personal source and semantic information are at once distinct and highly interactive within the framework of remote memory. (c) 2007 APA, all rights reserved.

[Revealing three psychological states before an acting out in 32 patients hospitalized for suicide attempt].

PubMed

Vandevoorde, J

2013-09-01

The purpose of this study was to reconstruct the psychological state of suicidal subjects at the time of the execution of the gesture according to their thoughts, their emotions, their actions, their fantasy life and consciousness. Thirty-three adult subjects agreed, just days after their suicide attempt, to answer the Interview Method for Suicidal Acts (IMSA). This object of this semi-structured interview is to invite the suicidal to reconstruct mentally and chronologically their suicide attempt. IMSA can follow the thoughts, behavior, consciousness, emotions and activity of the suicidal scenario by helping the patient to reconstruct the phenomenology of his/her actions until the final suicidal gesture. The data were processed using the method of Classification TwoStep on SPSS, based on Schwarz Bayesian criterion. The results highlight three main types of psychological state: (1) a "kinesthetic" psychological state (called "type K") is characterized by a rupture between the subjective sensation of motor movement and effective motility (motor automatism), the presence of a dissociative state, an "empty" feeling of thought and the absence of an external triggering factor; (2) a "cognitive" psychological state (called "type C") is characterized by a significant reflection on the decision to die and infiltration of the morbid thought, an intense fantasy life around the suicidal scenario, a clear state of consciousness, and an absence of loss of motor control; (3) an "emotional" psychological state (called "type E") is characterized by confusing and chaotic emotional processes, the emergence of a dissociative state, and a significant impact of external events on the onset of the suicide attempt. This classification of suicide attempts allows us to identify the different combinations of the suicidal process and opens up new therapeutic strategies. Copyright © 2013 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

ATLAS, an integrated structural analysis and design system. Volume 3: User's manual, input and execution data

NASA Technical Reports Server (NTRS)

Dreisbach, R. L. (Editor)

1979-01-01

The input data and execution control statements for the ATLAS integrated structural analysis and design system are described. It is operational on the Control Data Corporation (CDC) 6600/CYBER computers in a batch mode or in a time-shared mode via interactive graphic or text terminals. ATLAS is a modular system of computer codes with common executive and data base management components. The system provides an extensive set of general-purpose technical programs with analytical capabilities including stiffness, stress, loads, mass, substructuring, strength design, unsteady aerodynamics, vibration, and flutter analyses. The sequence and mode of execution of selected program modules are controlled via a common user-oriented language.

Concurrent and Short-term Prospective Relations among Neurocognitive Functioning, Coping, and Depressive Symptoms in Youth

PubMed Central

Evans, Lindsay D.; Kouros, Chrystyna D.; Samanez-Larkin, Silvia; Garber, Judy

2016-01-01

Objective The present short-term longitudinal study examined the concurrent and prospective relations among executive functioning (i.e., working memory and cognitive flexibility), coping (primary and secondary control coping), and depressive symptoms in children. Method Participants were 192 children between 9 and 15 years old (mean age = 12.36 years, SD = 1.77) recruited from the community. Youth were individually administered neuropsychological measures of executive functioning and intelligence, and completed self-report measures of executive dysfunction, coping, and depressive symptoms in small groups; the latter two measures were completed again four months later (Time 2). Linear regression analyses were used to examine direct associations among executive functions, coping, and depressive symptoms, and a bootstrapping procedure was used to test indirect effects of executive functioning on depressive symptoms through coping. Results Significant prospective relations were found between working memory measured at Time 1 (T1) and both primary and secondary control coping measured at Time 2 (T2), controlling for T1 coping. T1 cognitive flexibility significantly predicted T2 secondary control coping, controlling for T1 coping. Working memory deficits significantly predicted increases in depressive symptoms four months later, controlling for T1 depressive symptoms. Bootstrap analyses revealed that primary and secondary control coping each partially mediated the relation between working memory and depressive symptoms; secondary control coping partially mediated the relation between cognitive flexibility and depressive symptoms. Conclusion Coping may be one pathway through which deficits in executive functioning contribute to children's symptoms of depression. PMID:25651455

On low temperature glide of dissociated <1 1 0> dislocations in strontium titanate

NASA Astrophysics Data System (ADS)

Ritterbex, Sebastian; Hirel, Pierre; Carrez, Philippe

2018-05-01

An elastic interaction model is presented to quantify low temperature plasticity of SrTiO3 via glide of dissociated <1 1 0>{1 1 0} screw dislocations. Because <1 1 0> dislocations are dissociated, their glide, controlled by the kink-pair mechanism at T < 1050 K, involves the formation of kink-pairs on partial dislocations, either simultaneously or sequentially. Our model yields results in good quantitative agreement with the observed non-monotonic mechanical behaviour of SrTiO3. This agreement allows to explain the experimental results in terms of a (progressive) change in <1 1 0>{1 1 0} glide mechanism, from simultaneous nucleation of two kink-pairs along both partials at low stress, towards nucleation of single kink-pairs on individual partials if resolved shear stress exceeds a critical value of 95 MPa. High resolved shear stress allows thus for the activation of extra nucleation mechanisms on dissociated dislocations impossible to occur under the sole action of thermal activation. We suggest that stress condition in conjunction with core dissociation is key to the origin of non-monotonic plastic behaviour of SrTiO3 at low temperatures.

Individual Differences in Executive Functions Are Almost Entirely Genetic in Origin

ERIC Educational Resources Information Center

Friedman, Naomi P.; Miyake, Akira; Young, Susan E.; DeFries, John C.; Corley, Robin P.; Hewitt, John K.

2008-01-01

Recent psychological and neuropsychological research suggests that executive functions--the cognitive control processes that regulate thought and action--are multifaceted and that different types of executive functions are correlated but separable. The present multivariate twin study of 3 executive functions (inhibiting dominant responses,…

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.

Brain stem omnipause neurons and the control of combined eye-head gaze saccades in the alert cat.

PubMed

Paré, M; Guitton, D

1998-06-01

When the head is unrestrained, rapid displacements of the visual axis-gaze shifts (eye-re-space)-are made by coordinated movements of the eyes (eye-re-head) and head (head-re-space). To address the problem of the neural control of gaze shifts, we studied and contrasted the discharges of omnipause neurons (OPNs) during a variety of combined eye-head gaze shifts and head-fixed eye saccades executed by alert cats. OPNs discharged tonically during intersaccadic intervals and at a reduced level during slow perisaccadic gaze movements sometimes accompanying saccades. Their activity ceased for the duration of the saccadic gaze shifts the animal executed, either by head-fixed eye saccades alone or by combined eye-head movements. This was true for all types of gaze shifts studied: active movements to visual targets; passive movements induced by whole-body rotation or by head rotation about stationary body; and electrically evoked movements by stimulation of the caudal part of the superior colliculus (SC), a central structure for gaze control. For combined eye-head gaze shifts, the OPN pause was therefore not correlated to the eye-in-head trajectory. For instance, in active gaze movements, the end of the pause was better correlated with the gaze end than with either the eye saccade end or the time of eye counterrotation. The hypothesis that cat OPNs participate in controlling gaze shifts is supported by these results, and also by the observation that the movements of both the eyes and the head were transiently interrupted by stimulation of OPNs during gaze shifts. However, we found that the OPN pause could be dissociated from the gaze-motor-error signal producing the gaze shift. First, OPNs resumed discharging when perturbation of head motion briefly interrupted a gaze shift before its intended amplitude was attained. Second, stimulation of caudal SC sites in head-free cat elicited large head-free gaze shifts consistent with the creation of a large gaze-motor-error signal. However, stimulation of the same sites in head-fixed cat produced small "goal-directed" eye saccades, and OPNs paused only for the duration of the latter; neither a pause nor an eye movement occurred when the same stimulation was applied with the eyes at the goal location. We conclude that OPNs can be controlled by neither a simple eye control system nor an absolute gaze control system. Our data cannot be accounted for by existing models describing the control of combined eye-head gaze shifts and therefore put new constraints on future models, which will have to incorporate all the various signals that act synergistically to control gaze shifts.

The impact of dissociation on transposon-mediated disease control strategies.

PubMed

Marshall, John M

2008-03-01

Vector-borne diseases such as malaria and dengue fever continue to be a major health concern through much of the world. The emergence of chloroquine-resistant strains of malaria and insecticide-resistant mosquitoes emphasize the need for novel methods of disease control. Recently, there has been much interest in the use of transposable elements to drive resistance genes into vector populations as a means of disease control. One concern that must be addressed before a release is performed is the potential loss of linkage between a transposable element and a resistance gene. Transposable elements such as P and hobo have been shown to produce internal deletion derivatives at a significant rate, and there is concern that a similar process could lead to loss of the resistance gene from the drive system following a transgenic release. Additionally, transposable elements such as Himar1 have been shown to transpose significantly more frequently when free of exogenous DNA. Here, we show that any transposon-mediated gene drive strategy must have an exceptionally low rate of dissociation if it is to be effective. Additionally, the resistance gene must confer a large selective advantage to the vector to surmount the effects of a moderate dissociation rate and transpositional handicap.

Executive functioning in older adults with hoarding disorder.

PubMed

Ayers, Catherine R; Wetherell, Julie Loebach; Schiehser, Dawn; Almklov, Erin; Golshan, Shahrokh; Saxena, Sanjaya

2013-11-01

Hoarding disorder (HD) is a chronic and debilitating psychiatric condition. Midlife HD patients have been found to have neurocognitive impairment, particularly in areas of executive functioning, but the extent to which this is due to comorbid psychiatric disorders has not been clear. The purpose of the present investigation was to examine executive functioning in geriatric HD patients without any comorbid Axis I disorders (n = 42) compared with a healthy older adult comparison group (n = 25). We hypothesized that older adults with HD would perform significantly worse on measures of executive functioning (Wisconsin Card Sort Task [Psychological Assessment Resources, Lutz, Florida, USA] ( Psychological Assessment Resources, 2003) and the Wechsler Adult Intelligence Scale-IV digit span and letter-number sequencing tests [Pearson, San Antonio, TX, USA]). Older adults with HD showed significant differences from healthy older controls in multiple aspects of executive functioning. Compared with healthy controls, older adults with HD committed significantly more total, non-perseverative errors and conceptual level responses on the Wisconsin Card Sort Task and had significantly worse performance on the Wechsler Adult Intelligence Scale-IV digit span and letter-number sequencing tests. Hoarding symptom severity was strongly correlated with executive dysfunction in the HD group. Compared with demographically-matched controls, older adults with HD have dysfunction in several domains of executive functioning including mental control, working memory, inhibition, and set shifting. Executive dysfunction is strongly correlated with hoarding severity and is not because of comorbid psychiatric disorders in HD patients. These results have broad clinical implications suggesting that executive functioning should be assessed and taken into consideration when developing intervention strategies for older adults with HD. Copyright © 2013 John Wiley & Sons, Ltd.

Independence of Hot and Cold Executive Function Deficits in High-Functioning Adults with Autism Spectrum Disorder.

PubMed

Zimmerman, David L; Ownsworth, Tamara; O'Donovan, Analise; Roberts, Jacqueline; Gullo, Matthew J

2016-01-01

Individuals with autistic spectrum disorder (ASD) display diverse deficits in social, cognitive and behavioral functioning. To date, there has been mixed findings on the profile of executive function deficits for high-functioning adults (IQ > 70) with ASD. A conceptual distinction is commonly made between "cold" and "hot" executive functions. Cold executive functions refer to mechanistic higher-order cognitive operations (e.g., working memory), whereas hot executive functions entail cognitive abilities supported by emotional awareness and social perception (e.g., social cognition). This study aimed to determine the independence of deficits in hot and cold executive functions for high-functioning adults with ASD. Forty-two adults with ASD (64% male, aged 18-66 years) and 40 age and gender matched controls were administered The Awareness of Social Inference Test (TASIT; emotion recognition and social inference), Letter Number Sequencing (working memory) and Hayling Sentence Completion Test (response initiation and suppression). Between-group analyses identified that the ASD group performed significantly worse than matched controls on all measures of cold and hot executive functions (d = 0.54 - 1.5). Hierarchical multiple regression analyses revealed that the ASD sample performed more poorly on emotion recognition and social inference tasks than matched controls after controlling for cold executive functions and employment status. The findings also indicated that the ability to recognize emotions and make social inferences was supported by working memory and response initiation and suppression processes. Overall, this study supports the distinction between hot and cold executive function impairments for adults with ASD. Moreover, it advances understanding of higher-order impairments underlying social interaction difficulties for this population which, in turn, may assist with diagnosis and inform intervention programs.

Independence of Hot and Cold Executive Function Deficits in High-Functioning Adults with Autism Spectrum Disorder

PubMed Central

Zimmerman, David L.; Ownsworth, Tamara; O'Donovan, Analise; Roberts, Jacqueline; Gullo, Matthew J.

2016-01-01

Individuals with autistic spectrum disorder (ASD) display diverse deficits in social, cognitive and behavioral functioning. To date, there has been mixed findings on the profile of executive function deficits for high-functioning adults (IQ > 70) with ASD. A conceptual distinction is commonly made between “cold” and “hot” executive functions. Cold executive functions refer to mechanistic higher-order cognitive operations (e.g., working memory), whereas hot executive functions entail cognitive abilities supported by emotional awareness and social perception (e.g., social cognition). This study aimed to determine the independence of deficits in hot and cold executive functions for high-functioning adults with ASD. Forty-two adults with ASD (64% male, aged 18–66 years) and 40 age and gender matched controls were administered The Awareness of Social Inference Test (TASIT; emotion recognition and social inference), Letter Number Sequencing (working memory) and Hayling Sentence Completion Test (response initiation and suppression). Between-group analyses identified that the ASD group performed significantly worse than matched controls on all measures of cold and hot executive functions (d = 0.54 − 1.5). Hierarchical multiple regression analyses revealed that the ASD sample performed more poorly on emotion recognition and social inference tasks than matched controls after controlling for cold executive functions and employment status. The findings also indicated that the ability to recognize emotions and make social inferences was supported by working memory and response initiation and suppression processes. Overall, this study supports the distinction between hot and cold executive function impairments for adults with ASD. Moreover, it advances understanding of higher-order impairments underlying social interaction difficulties for this population which, in turn, may assist with diagnosis and inform intervention programs. PMID:26903836

Proverb comprehension impairments in schizophrenia are related to executive dysfunction.

PubMed

Thoma, Patrizia; Hennecke, Marie; Mandok, Tobias; Wähner, Alfred; Brüne, Martin; Juckel, Georg; Daum, Irene

2009-12-30

The study aimed to investigate the pattern of proverb comprehension impairment and its relationship to proverb familiarity and executive dysfunction in schizophrenia. To assess the specificity of the impairment pattern to schizophrenia, alcohol-dependent patients were included as a psychiatric comparison group, as deficits of executive function and theory of mind as well as dysfunction of the prefrontal cortex, which have been related to proverb comprehension difficulties, are common in both disorders. Twenty-four schizophrenia patients, 20 alcohol-dependent patients and 34 healthy controls were administered a multiple-choice proverb interpretation task incorporating ratings of subjective familiarity and measures of executive function. Schizophrenia patients chose the correct abstract and meaningful interpretations less frequently and instead chose the incorrect concrete (both meaningless and meaningful) proverb interpretations more often than alcohol-dependent patients and healthy controls. Relative to healthy controls, schizophrenia patients also chose more abstract-meaningless response alternatives and were impaired in all executive domains. Impaired divided attention was most consistently associated with proverb interpretation deficits in both patient groups. Taken together, schizophrenia patients showed a specific pattern of proverb comprehension impairments related to executive dysfunction and symptoms. The comparison with the alcohol-dependent subgroup suggests that a more comprehensive and severe impairment of complex higher-order cognitive functions including executive behavioural control and non-literal language comprehension might be associated with frontal dysfunction in schizophrenia as compared to alcohol use disorder.

Protein kinase A inhibitor, H89, enhances survival and clonogenicity of dissociated human embryonic stem cells through Rho-associated coiled-coil containing protein kinase (ROCK) inhibition.

PubMed

Zhang, Liang; Xu, Yanqing; Xu, Jiandong; Wei, Yuping; Xu, Xia

2016-04-01

Can cell survival of dissociated human embryonic stem cells (hESCs) be increased during culture? A protein kinase A (PKA) inhibitor, H89, can significantly enhance survival and clonogenicity of dissociated hESCs without affecting their pluripotency. hESCs are vulnerable to massive cell death upon cellular detachment and dissociation. hESCs were dissociated into single cells and then cultured in feeder-dependent and -independent manners. H89 was added to the culture medium at different concentrations for 1 day. The statistical results were obtained from at least three independent experiments (n ≥ 4). The group without treatment was used as the negative control. 4 µM H89 was added in the culture medium to promote cell survival and colony formation of dissociated hESCs. MTT method and propidium iodide (PI) staining were used to determine cell proliferation, cell death and cell cycle, respectively. To count colony formation, alkaline phosphatase (AP) staining was carried out. Western blot was performed to determine protein expression. Except AP staining, immunofluorescence, RT-PCR and karyotype analysis were used to confirm the pluripotent state of H89 treated hESCs. H89 inhibits the dissociation-induced phosphorylation of PKA and two substrates of Rho-associated coiled-coil containing protein kinase (ROCK), myosin light chain (MLC2) and myosin phosphatase target subunit 1 (MYPT1), significantly increases cell survival and colony formation, and strongly depresses dissociation-induced cell death and cell blebbing without affecting the pluripotency of hESCs and their differentiation in vitro. Appropriate H89 concentration should be used and 1 day of H89 treatment is sufficient for promoting survival and colony formation of dissociated hESCs. These results provide an alternative for human pluripotent stem cell (hPSC) culture, broaden the scope of participants in the cell death of single hES cells after dissociation and further enlighten clues to understand the mechanism of dissociation-induced cell death. This research was supported by the National Natural Science Foundation of China (21176238, 21576266), and Chinese Academy of Sciences. There is no conflict of interest to declare. Nil. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Strategy difficulty effects in young and older adults' episodic memory are modulated by inter-stimulus intervals and executive control processes.

PubMed

Burger, Lucile; Uittenhove, Kim; Lemaire, Patrick; Taconnat, Laurence

2017-04-01

Efficient execution of strategies is crucial to memory performance and to age-related differences in this performance. Relative strategy complexity influences memory performance and aging effects on memory. Here, we aimed to further our understanding of the effects of relative strategy complexity by looking at the role of cognitive control functions and the time-course of the effects of relative strategy complexity. Thus, we manipulated inter-stimulus intervals (ISI) and assessed executive functions. Results showed that (a) performance as a function of the relative strategy difficulty of the current and previous trial was modulated by ISI, (b) these effects were modulated by inhibition capacities, and (c) significant age differences were found in the way ISI modulates relative strategy difficulty. These findings have important implications for understanding the relationships between aging, executive control, and strategy execution in episodic memory. Copyright © 2017 Elsevier B.V. All rights reserved.

A science-based executive for autonomous planetary vehicles

NASA Technical Reports Server (NTRS)

Peters, S.

2001-01-01

If requests for scientific observations, rather than specific plans, are uplinked to an autonomous execution system on the vehicle, it would be able to adjust its execution based upon actual performance. Such a science-based executive control system had been developed and demonstrated for the Rocky7 research rover.

Mindfulness Meditation Training and Executive Control Network Resting State Functional Connectivity: A Randomized Controlled Trial.

PubMed

Taren, Adrienne A; Gianaros, Peter J; Greco, Carol M; Lindsay, Emily K; Fairgrieve, April; Brown, Kirk Warren; Rosen, Rhonda K; Ferris, Jennifer L; Julson, Erica; Marsland, Anna L; Creswell, J David

Mindfulness meditation training has been previously shown to enhance behavioral measures of executive control (e.g., attention, working memory, cognitive control), but the neural mechanisms underlying these improvements are largely unknown. Here, we test whether mindfulness training interventions foster executive control by strengthening functional connections between dorsolateral prefrontal cortex (dlPFC)-a hub of the executive control network-and frontoparietal regions that coordinate executive function. Thirty-five adults with elevated levels of psychological distress participated in a 3-day randomized controlled trial of intensive mindfulness meditation or relaxation training. Participants completed a resting state functional magnetic resonance imaging scan before and after the intervention. We tested whether mindfulness meditation training increased resting state functional connectivity (rsFC) between dlPFC and frontoparietal control network regions. Left dlPFC showed increased connectivity to the right inferior frontal gyrus (T = 3.74), right middle frontal gyrus (MFG) (T = 3.98), right supplementary eye field (T = 4.29), right parietal cortex (T = 4.44), and left middle temporal gyrus (T = 3.97, all p < .05) after mindfulness training relative to the relaxation control. Right dlPFC showed increased connectivity to right MFG (T = 4.97, p < .05). We report that mindfulness training increases rsFC between dlPFC and dorsal network (superior parietal lobule, supplementary eye field, MFG) and ventral network (right IFG, middle temporal/angular gyrus) regions. These findings extend previous work showing increased functional connectivity among brain regions associated with executive function during active meditation by identifying specific neural circuits in which rsFC is enhanced by a mindfulness intervention in individuals with high levels of psychological distress. Clinicaltrials.gov,NCT01628809.

Salient cues improve prospective remembering in Korsakoff's syndrome.

PubMed

Altgassen, Mareike; Ariese, Laura; Wester, Arie J; Kessels, Roy P C

2016-06-01

Korsakoff's syndrome is characterized by deficits in episodic memory and executive functions. Both cognitive functions are needed to remember to execute delayed intentions (prospective memory, PM), an ability that is crucial for independent living in everyday life. So far, PM has only been targeted by one study in Korsakoff's syndrome. This study explored the effects of executive control demands on PM to shed further light on a possible interdependence of memory and executive functions in Korsakoff's syndrome, Twenty-five individuals with Korsakoff's syndrome and 23 chronic alcoholics (without amnesia) performed a categorization task into which a PM task was embedded that put either high or low demands on executive control processes (using low vs. high salient cues). Overall, Korsakoff patients had fewer PM hits than alcoholic controls. Across groups, participants had fewer PM hits when cues were low salient as compared to high salient. Korsakoff patients performed better on PM when highly salient cues were presented than cues of low salience, while there were no differential effects for alcoholic controls. While overall Korsakoff patients' showed a global PM deficit, the extent of this deficit was moderated by the executive control demands of the task applied. This indicated further support for an interrelation of executive functions and memory performance in Korsakoff. Positive clinical implications of the work Prospective memory (PM) performance in Korsakoff's syndrome is related to executive control load. Increasing cues' salience improves PM performance in Korsakoff's syndrome. Salient visual aids may be used in everyday life to improve Korsakoff individuals' planning and organization skills. Cautions or limitations of the study Results were obtained in a structured laboratory setting and need to be replicated in a more naturalistic setting to assess their transferability to everyday life. Given the relatively small sample size, individual predictors of PM performance should be determined in larger samples. © 2015 The British Psychological Society.

Executive Control of Attention in Narcolepsy

PubMed Central

Bayard, Sophie; Croisier Langenier, Muriel; Cochen De Cock, Valérie; Scholz, Sabine; Dauvilliers, Yves

2012-01-01

Background Narcolepsy with cataplexy (NC) is a disabling sleep disorder characterized by early loss of hypocretin neurons that project to areas involved in the attention network. We characterized the executive control of attention in drug-free patients with NC to determine whether the executive deficits observed in patients with NC are specific to the disease itself or whether they reflect performance changes due to the severity of excessive daytime sleepiness. Methodology Twenty-two patients with NC compared to 22 patients with narcolepsy without cataplexy (NwC) matched for age, gender, intellectual level, objective daytime sleepiness and number of sleep onset REM periods (SOREMPs) were studied. Thirty-two matched healthy controls were included. All participants underwent a standardized interview, completed questionnaires, and neuropsychological tests. All patients underwent a polysomnography followed by multiple sleep latency tests (MSLT), with neuropsychological evaluation performed the same day between MSLT sessions. Principal Findings Irrespective of diagnosis, patients reported higher self-reported attentional complaints associated with the intensity of depressive symptoms. Patients with NC performed slower and more variably on simple reaction time tasks than patients with NwC, who did not differ from controls. Patients with NC and NwC generally performed slower, reacted more variably, and made more errors than controls on executive functioning tests. Individual profile analyses showed a clear heterogeneity of the severity of executive deficit. This severity was related to objective sleepiness, higher number of SOREMPs on the MSLT, and lower intelligence quotient. The nature and severity of the executive deficits were unrelated to NC and NwC diagnosis. Conclusions We demonstrated that drug-free patients with NC and NwC complained of attention deficit, with altered executive control of attention being explained by the severity of objective sleepiness and global intellectual level. Further studies are needed to explore whether medications that promote wakefulness can improve the executive functions in narcolepsy. PMID:22558075

Altered affective, executive and sensorimotor resting state networks in patients with pediatric mania

PubMed Central

Wu, Minjie; Lu, Lisa H.; Passarotti, Alessandra M.; Wegbreit, Ezra; Fitzgerald, Jacklynn; Pavuluri, Mani N.

2013-01-01

Background The aim of the present study was to map the pathophysiology of resting state functional connectivity accompanying structural and functional abnormalities in children with bipolar disorder. Methods Children with bipolar disorder and demographically matched healthy controls underwent resting-state functional magnetic resonance imaging. A model-free independent component analysis was performed to identify intrinsically interconnected networks. Results We included 34 children with bipolar disorder and 40 controls in our analysis. Three distinct resting state networks corresponding to affective, executive and sensorimotor functions emerged as being significantly different between the pediatric bipolar disorder (PBD) and control groups. All 3 networks showed hyperconnectivity in the PBD relative to the control group. Specifically, the connectivity of the dorsal anterior cingulate cortex (ACC) differentiated the PBD from the control group in both the affective and the executive networks. Exploratory analysis suggests that greater connectivity of the right amygdala within the affective network is associated with better executive function in children with bipolar disorder, but not in controls. Limitations Unique clinical characteristics of the study sample allowed us to evaluate the pathophysiology of resting state connectivity at an early state of PBD, which led to the lack of generalizability in terms of comorbid disorders existing in a typical PBD population. Conclusion Abnormally engaged resting state affective, executive and sensorimotor networks observed in children with bipolar disorder may reflect a biological context in which abnormal task-based brain activity can occur. Dual engagement of the dorsal ACC in affective and executive networks supports the neuroanatomical interface of these networks, and the amygdala’s engagement in moderating executive function illustrates the intricate interplay of these neural operations at rest. PMID:23735583

Heart rate variability during carbachol-induced REM sleep and cataplexy.

PubMed

Torterolo, Pablo; Castro-Zaballa, Santiago; Cavelli, Matías; Velasquez, Noelia; Brando, Victoria; Falconi, Atilio; Chase, Michael H; Migliaro, Eduardo R

2015-09-15

The nucleus pontis oralis (NPO) exerts an executive control over REM sleep. Cholinergic input to the NPO is critical for REM sleep generation. In the cat, a single microinjection of carbachol (a cholinergic agonist) into the NPO produces either REM sleep (REMc) or wakefulness with muscle atonia (cataplexy, CA). In order to study the central control of the heart rate variability (HRV) during sleep, we conducted polysomnographic and electrocardiogram recordings from chronically prepared cats during REMc, CA as well as during sleep and wakefulness. Subsequently, we performed statistical and spectral analyses of the HRV. The heart rate was greater during CA compared to REMc, NREM or REM sleep. Spectral analysis revealed that the low frequency band (LF) power was significantly higher during REM sleep in comparison to REMc and CA. Furthermore, we found that during CA there was a decrease in coupling between the RR intervals plot (tachogram) and respiratory activity. In contrast, compared to natural behavioral states, during REMc and CA there were no significant differences in the HRV based upon the standard deviation of normal RR intervals (SDNN) and the mean squared difference of successive intervals (rMSSD). In conclusion, there were differences in the HRV during naturally-occurring REM sleep compared to REMc. In addition, in spite of the same muscle atonia, the HRV was different during REMc and CA. Therefore, the neuronal network that controls the HRV during REM sleep can be dissociated from the one that generates the muscle atonia during this state. Copyright © 2015 Elsevier B.V. All rights reserved.

Retrieval Search and Strength Evoke Dissociable Brain Activity during Episodic Memory Recall

PubMed Central

Reas, Emilie T.; Brewer, James B.

2014-01-01

Neuroimaging studies of episodic memory retrieval have revealed activations in the human frontal, parietal, and medial-temporal lobes that are associated with memory strength. However, it remains unclear whether these brain responses are veritable signals of memory strength or are instead regulated by concomitant subcomponents of retrieval such as retrieval effort or mental search. This study used event-related fMRI during cued recall of previously memorized word-pair associates to dissociate brain responses modulated by memory search from those modulated by the strength of a recalled memory. Search-related deactivations, dissociated from activity due to memory strength, were observed in regions of the default network, whereas distinctly strength-dependent activations were present in superior and inferior parietal and dorsolateral PFC. Both search and strength regulated activity in dorsal anterior cingulate and anterior insula. These findings suggest that, although highly correlated and partially subserved by overlapping cognitive control mechanisms, search and memory strength engage dissociable regions of frontoparietal attention and default networks. PMID:23190328

Theoretical study of the photodissociation of Li(2)+ in one-color intense laser fields.

PubMed

Li, Yuanjun; Jiang, Wanyi; Khait, Yuriy G; Hoffmann, Mark R

2011-05-07

A theoretical treatment of the photodissociation of the molecular ion Li(2) (+) in one-color intense laser fields, using the time-dependent wave packet approach in a Floquet Born-Oppenheimer representation, is presented. Six electronic states 1,2 (2)Σ(g)(+), 1,2 (2)Σ(u)(+), 1 (2)Π(g), and 1 (2)Π(u) are of relevance in this simulation and have been included. The dependences of the fragmental dissociation probabilities and kinetic energy release (KER) spectra on pulse width, peak intensity, polarization angle, wavelength, and initial vibrational level are analyzed to interpret the influence of control parameters of the external field. Three main dissociation channels, 1 (2)Σ(g)(+) (m = -1), 2 (2)Σ(g)(+) (m = -2), and 2 (2)Σ(u)(+) (m = -3), are seen to dominate the dissociation processes under a wide variety of laser conditions and give rise to well separated groups of KER features. Different dissociation mechanisms for the involved Floquet channels are discussed.

[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.

Phosphorylation of the centrosomal protein, Cep169, by Cdk1 promotes its dissociation from centrosomes in mitosis.

PubMed

Mori, Yusuke; Inoue, Yoko; Taniyama, Yuki; Tanaka, Sayori; Terada, Yasuhiko

2015-12-25

Cep169 is a centrosomal protein conserved among vertebrates. In our previous reports, we showed that mammalian Cep169 interacts and collaborates with CDK5RAP2 to regulate microtubule (MT) dynamics and stabilization. Although Cep169 is required for MT regulation, its precise cellular function remains largely elusive. Here we show that Cep169 associates with centrosomes during interphase, but dissociates from these structures from the onset of mitosis, although CDK5RAP2 (Cep215) is continuously located at the centrosomes throughout cell cycle. Interestingly, treatment with purvalanol A, a Cdk1 inhibitor, nearly completely blocked the dissociation of Cep169 from centrosomes during mitosis. In addition, mass spectrometry analyses identified 7 phosphorylated residues of Cep169 corresponding to consensus phosphorylation sequence for Cdk1. These data suggest that the dissociation of Cep169 from centrosomes is controlled by Cdk1/Cyclin B during mitosis, and that Cep169 might regulate MT dynamics of mitotic spindle. Copyright © 2015 Elsevier Inc. All rights reserved.

N-type molecular electrical doping in organic semiconductors: formation and dissociation efficiencies of charge transfer complex

NASA Astrophysics Data System (ADS)

Kim, Jae-Min; Yoo, Seung-Jun; Moon, Chang-Ki; Sim, Bomi; Lee, Jae-Hyun; Lim, Heeseon; Kim, Jeong Won; Kim, Jang-Joo

2016-09-01

Electrical doping is an important method in organic electronics to enhance device efficiency by controlling Fermi level, increasing conductivity, and reducing injection barrier from electrode. To understand the charge generation process of dopant in doped organic semiconductors, it is important to analyze the charge transfer complex (CTC) formation and dissociation into free charge carrier. In this paper, we correlate charge generation efficiency with the CTC formation and dissociation efficiency of n-dopant in organic semiconductors (OSs). The CTC formation efficiency of Rb2CO3 linearly decreases from 82.8% to 47.0% as the doping concentration increases from 2.5 mol% to 20 mol%. The CTC formation efficiency and its linear decrease with doping concentration are analytically correlated with the concentration-dependent size and number of dopant agglomerates by introducing the degree of reduced CTC formation. Lastly, the behavior of dissociation efficiency is discussed based on the picture of the statistical semiconductor theory and the frontier orbital hybridization model.

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.

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Early stage second-language learning improves executive control: evidence from ERP.

PubMed

Sullivan, Margot D; Janus, Monika; Moreno, Sylvain; Astheimer, Lori; Bialystok, Ellen

2014-12-01

A growing body of research has reported a bilingual advantage in performance on executive control tasks, but it is not known at what point in emerging bilingualism these advantages first appear. The present study investigated the effect of early stage second-language training on executive control. Monolingual English-speaking students were tested on a go-nogo task, sentence judgment task, and verbal fluency, before and after 6 months of Spanish instruction. The training group (n = 25) consisted of students enrolled in introductory Spanish and the control group (n = 30) consisted of students enrolled in introductory Psychology. After training, the Spanish group showed larger P3 amplitude on the go-nogo task and smaller P600 amplitude on the judgment task, indicating enhanced performance, with no changes for the control group and no differences between groups on behavioral measures. Results are discussed in terms of neural changes underlying executive control after brief second-language learning. Copyright © 2014 Elsevier Inc. All rights reserved.

Memory and executive functions in patients with obsessive-compulsive disorder.

PubMed

Vandborg, Sanne Kjær; Hartmann, Tue Borst; Bennedsen, Birgit Egedal; Pedersen, Anders Degn; Thomsen, Per Hove

2014-03-01

We investigated whether patients with obsessive-compulsive disorder have poorer memory and executive functions than healthy controls. The relatively inconsistent previous findings on this question reflect a lack of well-matched control groups, the inclusion of patients with comorbidity, and the use of noncomparable neuropsychological tests to assess memory and executive functions. We used well-accepted neuropsychological tests of memory and executive functions to assess 42 patients who had obsessive-compulsive disorder without comorbidity, and 42 healthy controls. We matched the patients and controls pairwise by sex, age, and years of education. The patients performed significantly worse than the controls on the Rey Complex Figure Test, which assesses visuospatial memory and organizational skills. This group difference remained after we controlled for age, education, intelligence, and severity of depressive symptoms. The findings indicate that patients with obsessive-compulsive disorder may have impaired visuospatial memory and organizational skills, and these impairments should be considered in treatment. ClinicalTrials.gov NCT00792038.

NPTool: Towards Scalability and Reliability of Business Process Management

NASA Astrophysics Data System (ADS)

Braghetto, Kelly Rosa; Ferreira, João Eduardo; Pu, Calton

Currently one important challenge in business process management is provide at the same time scalability and reliability of business process executions. This difficulty becomes more accentuated when the execution control assumes complex countless business processes. This work presents NavigationPlanTool (NPTool), a tool to control the execution of business processes. NPTool is supported by Navigation Plan Definition Language (NPDL), a language for business processes specification that uses process algebra as formal foundation. NPTool implements the NPDL language as a SQL extension. The main contribution of this paper is a description of the NPTool showing how the process algebra features combined with a relational database model can be used to provide a scalable and reliable control in the execution of business processes. The next steps of NPTool include reuse of control-flow patterns and support to data flow management.

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.

Speed and Lateral Inhibition of Stimulus Processing Contribute to Individual Differences in Stroop-Task Performance.

PubMed

Naber, Marnix; Vedder, Anneke; Brown, Stephen B R E; Nieuwenhuis, Sander

2016-01-01

The Stroop task is a popular neuropsychological test that measures executive control. Strong Stroop interference is commonly interpreted in neuropsychology as a diagnostic marker of impairment in executive control, possibly reflecting executive dysfunction. However, popular models of the Stroop task indicate that several other aspects of color and word processing may also account for individual differences in the Stroop task, independent of executive control. Here we use new approaches to investigate the degree to which individual differences in Stroop interference correlate with the relative processing speed of word and color stimuli, and the lateral inhibition between visual stimuli. We conducted an electrophysiological and behavioral experiment to measure (1) how quickly an individual's brain processes words and colors presented in isolation (P3 latency), and (2) the strength of an individual's lateral inhibition between visual representations with a visual illusion. Both measures explained at least 40% of the variance in Stroop interference across individuals. As these measures were obtained in contexts not requiring any executive control, we conclude that the Stroop effect also measures an individual's pre-set way of processing visual features such as words and colors. This study highlights the important contributions of stimulus processing speed and lateral inhibition to individual differences in Stroop interference, and challenges the general view that the Stroop task primarily assesses executive control.

Functional Dissociation of Latency-Variable, Stimulus- and Response-Locked Target P3 Sub-components in Task-Switching.

PubMed

Brydges, Christopher R; Barceló, Francisco

2018-01-01

Cognitive control warrants efficient task performance in dynamic and changing environments through adjustments in executive attention, stimulus and response selection. The well-known P300 component of the human event-related potential (ERP) has long been proposed to index "context-updating"-critical for cognitive control-in simple target detection tasks. However, task switching ERP studies have revealed both target P3 (300-350 ms) and later sustained P3-like potentials (400-1,200 ms) to first targets ensuing transition cues, although it remains unclear whether these target P3-like potentials also reflect context updating operations. To address this question, we applied novel single-trial EEG analyses-residue iteration decomposition (RIDE)-in order to disentangle target P3 sub-components in a sample of 22 young adults while they either repeated or switched (updated) task rules. The rationale was to revise the context updating hypothesis of P300 elicitation in the light of new evidence suggesting that "the context" consists of not only the sensory units of stimulation, but also associated motor units, and intermediate low- and high-order sensorimotor units, all of which may need to be dynamically updated on a trial by trial basis. The results showed functionally distinct target P3-like potentials in stimulus-locked, response-locked, and intermediate RIDE component clusters overlying parietal and frontal regions, implying multiple functionally distinct, though temporarily overlapping context updating operations. These findings support a reformulated version of the context updating hypothesis, and reveal a rich family of distinct target P3-like sub-components during the reactive control of target detection in task-switching, plausibly indexing the complex and dynamic workings of frontoparietal cortical networks subserving cognitive control.

Risky decision-making under risk in schizophrenia: A deliberate choice?

PubMed

Pedersen, Anya; Göder, Robert; Tomczyk, Samuel; Ohrmann, Patricia

2017-09-01

Patients with schizophrenia reveal impaired decision-making strategies causing social, financial and health care problems. The extent to which deficits in decision-making reflect intentional risky choices in schizophrenia is still under debate. Based on previous studies we expected patients with schizophrenia to reveal a riskier performance on the GDT and to make more disadvantageous decisions on the IGT. In the present study, we investigated 38 patients with schizophrenia and 38 matched healthy control subjects with two competing paradigms regarding feedback: (1) The Game of Dice Task (GDT), in which the probabilities of winning or losing are stable and explicitly disclosed to the subject, to assess decision-making under risk and (2) the Iowa Gambling Task (IGT), which requires subjects to infer the probabilities of winning or losing from feedback, to investigate decision-making under ambiguity. Patients with schizophrenia revealed an overall riskier performance on the GDT; although they adjusted their strategy over the course of the GDT, they still made significantly more disadvantageous choices than controls. More positive symptoms in patients with schizophrenia indicated by higher PANSS positive scores were associated with riskier choices and less use of negative feedback. Compared to healthy controls, they were not impaired in net score but chose more disadvantageous cards than controls on the first block of the IGT. Effects of medication at the time of testing cannot be ruled out. Our findings suggest that patients with schizophrenia make riskier decisions and are less able to regulate their decision-making to implement advantageous strategies, even when the probabilities of winning or losing are explicitly disclosed. The dissociation between performance on the GDT and IGT suggests a pronounced impairment of executive functions related to the dorsolateral prefrontal cortex. Copyright © 2016 Elsevier Ltd. All rights reserved.

Functional resting-state networks are differentially affected in schizophrenia

PubMed Central

Woodward, Neil D.; Rogers, Baxter; Heckers, Stephan

2011-01-01

Neurobiological theories posit that schizophrenia relates to disturbances in connectivity between brain regions. Resting-state functional magnetic resonance imaging is a powerful tool for examining functional connectivity and has revealed several canonical brain networks, including the default mode, dorsal attention, executive control, and salience networks. The purpose of this study was to examine changes in these networks in schizophrenia. 42 patients with schizophrenia and 61 healthy subjects completed a RS-fMRI scanning session. Seed-based region-of-interest correlation analysis was used to identify the default mode, dorsal attention, executive control, and salience networks. Compared to healthy subjects, individuals with schizophrenia demonstrated greater connectivity between the posterior cingulate cortex, a key hub of the default mode, and the left inferior gyrus, left middle frontal gyrus, and left middle temporal gyrus. Interestingly, these regions were more strongly connected to the executive control network in healthy control subjects. In contrast to the default mode, patients demonstrated less connectivity in the executive control and dorsal attention networks. No differences were observed in the salience network. The results indicate that resting-state networks are differentially affected in schizophrenia. The alterations are characterized by reduced segregation between the default mode and executive control networks in the prefrontal cortex and temporal lobe, and reduced connectivity in the dorsal attention and executive control networks. The changes suggest that the process of functional specialization is altered in schizophrenia. Further work is needed to determine if the alterations are related to disturbances in white matter connectivity, neurodevelopmental abnormalities, and genetic risk for schizophrenia. PMID:21458238

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.

Paradoxical Pain Perception in Posttraumatic Stress Disorder: The Unique Role of Anxiety and Dissociation.

PubMed

Defrin, Ruth; Schreiber, Shaul; Ginzburg, Karni

2015-10-01

Posttraumatic stress disorder (PTSD) and chronic pain often co-occur and exacerbate each other. Elucidating the mechanism of this co-occurrence therefore has clinical importance. Previously, patients with PTSD with chronic pain were found to demonstrate a unique paradoxical pain profile: hyperresponsiveness together with hyposensitivity to pain. Our aim was to examine whether 2 seemingly paradoxical facets of PTSD (anxiety and dissociation) underlie this paradoxical profile. Patients with PTSD (n = 32) and healthy control individuals (n = 43) underwent psychophysical testing and completed questionnaires. Patients with PTSD had higher pain thresholds and higher pain ratings to suprathreshold stimuli than control individuals. Pain thresholds were positively associated with dissociation levels and negatively associated with anxiety sensitivity levels. Experimental pain ratings were positively associated with anxiety sensitivity and negatively related to dissociation levels. Chronic pain intensity was associated with anxiety, anxiety sensitivity, and pain catastrophizing. It appears that reduced conscious attention toward incoming stimuli, resulting from dissociation, causes delayed response in pain threshold measurement, whereas biases toward threatening stimuli and decreased inhibition, possibly caused by increased anxiety, are responsible for the intensification of experimental and chronic pain. The paradoxical facets of PTSD and their particular influences over pain perception seem to reinforce the coexistence of PTSD and chronic pain, and should be considered when treating traumatized individuals. This article provides new information regarding the underlying mechanism of the coexistence of PTSD and chronic pain. This knowledge could help to provide better management of PTSD and chronic pain among individuals in the aftermath of trauma. Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.

Mood effects on memory and executive control in a real-life situation.

PubMed

Lagner, Prune; Kliegel, Matthias; Phillips, Louise H; Ihle, Andreas; Hering, Alexandra; Ballhausen, Nicola; Schnitzspahn, Katharina M

2015-01-01

In the laboratory, studies have shown an inconsistent pattern of whether, and how, mood may affect cognitive functions indicating both mood-related enhancement as well as decline. Surprisingly, little is known about whether there are similar effects in everyday life. Hence, the present study aimed to investigate possible mood effects on memory and executive control in a real-life situation. Mood effects were examined in the context of winning in a sports competition. Sixty-one male handball players were tested with an extensive cognitive test battery (comprising memory and executive control) both after winning a match and after training as neutral baseline. Mood differed significantly between the two testing situations, while physiological arousal and motivation were comparable. Results showed lowered performance after the win compared with training in selected cognitive measures. Specifically, short-term and episodic memory performance was poorer following a win, whereas executive control performance was unaffected by condition. Differences in memory disappeared when emotional states after the match were entered as covariates into the initial analyses. Thus, findings suggest mood-related impairments in memory, but not in executive control processes after a positive real-life event.

Reduced Specificity of Autobiographical Memory and Depression

PubMed Central

Dalgleish, Tim; Williams, J. Mark G.; Golden, Ann-Marie J.; Perkins, Nicola; Barrett, Lisa Feldman; Barnard, Phillip J.; Yeung, Cecilia Au; Murphy, Victoria; Elward, Rachael; Tchanturia, Kate; Watkins, Edward

2007-01-01

It has been widely established that depressed mood states and clinical depression, as well as a range of other psychiatric disorders, are associated with a relative difficulty in accessing specific autobiographical information in response to emotion-related cue words on an Autobiographical Memory Test (AMT; J. M. G. Williams & K. Broadbent, 1986). In 8 studies the authors examined the extent to which this relationship is a function of impaired executive control associated with these mood states and clinical disorders. Studies 1–4 demonstrated that performance on the AMT is associated with performance on measures of executive control, independent of depressed mood. Furthermore, Study 1 showed that executive control (as measured by verbal fluency) mediated the relationship between both depressed mood and a clinical diagnosis of eating disorder and AMT performance. Using a stratified sample in Study 5, the authors confirmed the positive association between depressed mood and impaired performance on the AMT. Studies 6–8 involved experimental manipulations of the parameters of the AMT designed to further indicate that reduced executive control is to a significant extent driving the relationship between depressed mood and AMT performance. The potential role of executive control in accounting for other aspects of the AMT literature is discussed. PMID:17324083

Executive Functions in Intellectual Disabilities: A Comparison between Williams Syndrome and Down Syndrome

ERIC Educational Resources Information Center

Costanzo, Floriana; Varuzza, Cristiana; Menghini, Deny; Addona, Francesca; Gianesini, Tiziana; Vicari, Stefano

2013-01-01

Executive functions are a set of high cognitive abilities that control and regulate other functions and behaviors and are crucial for successful adaptation. Deficits in executive functions are frequently described in developmental disorders, which are characterized by disadaptive behavior. However, executive functions are not widely examined in…

Does the greater involvement of executive control in memory with age act as a compensatory mechanism?

PubMed

Bouazzaoui, Badiâa; Angel, Lucie; Fay, Séverine; Taconnat, Laurence; Charlotte, Froger; Isingrini, Michel

2014-03-01

Recent behavioural and imaging data have shown that memory functioning seems to rely more on executive functions and on the prefrontal cortex (PFC) in older than in young adults. Using a behavioural approach, our objective was to confirm the hypothesis that young and older adults present different patterns of correlation between episodic memory performance and executive functioning. We report three studies comparing the correlations of young and older adults in a broad range of episodic memory and executive function tasks. The results indicated that memory and executive performance were consistently and significantly correlated in older but not in younger adults. Regression analyses confirmed that age-related differences in episodic memory performance could be explained by individual differences in executive functioning. The results are consistent with the view that memory functioning in aging is accompanied by a shift from automatic to controlled forms of processing. They also generalise the executive hypothesis of episodic memory aging and are in line with the idea that executive functions act as a compensatory mechanism against age-related memory decline.

Executive functions, impulsivity, and inhibitory control in adolescents: A structural equation model

PubMed Central

Fino, Emanuele; Melogno, Sergio; Iliceto, Paolo; D’Aliesio, Sara; Pinto, Maria Antonietta; Candilera, Gabriella; Sabatello, Ugo

2014-01-01

Background. Adolescence represents a critical period for brain development, addressed by neurodevelopmental models to frontal, subcortical-limbic, and striatal activation, a pattern associated with rise of impulsivity and deficits in inhibitory control. The present study aimed at studying the association between self-report measures of impulsivity and inhibitory control with executive function in adolescents, employing structural equation modeling. Method. Tests were administered to 434 high school students. Acting without thinking was measured through the Barratt Impulsiveness Scale and the Dickman Impulsivity Inventory, reward sensitivity through the Behavioral Activation System, and sensation seeking through the Zuckerman–Kuhlman–Aluja Personali- ty Questionnaire. Inhibitory control was assessed through the Behavioral Inhibition System. The performance at the Wisconsin Card Sorting Task indicated executive function. Three models were specified using Sample Covariance Matrix, and the estimated parameters using Maximum Likelihood. Results. In the final model, impulsivity and inhibitory control predicted executive function, but sensation seeking did not. The fit of the model to data was excellent. Conclusions. The hypothesis that inhibitory control and impulsivity are predictors of executive function was supported. Our results appear informative of the validity of self-report measures to examine the relation between impulsivity traits rather than others to regulatory function of cognition and behavior. PMID:25157298

The Role of Executive Control and Readiness to Change in Problematic Drinkers with Mild to Borderline Intellectual Disability.

PubMed

van Duijvenbode, Neomi; Didden, Robert; Korzilius, Hubert P L M; Engels, Rutger C M E

2017-09-01

Problematic alcohol use is associated with neuropsychological consequences, including cognitive biases. The goal of the study was to explore the moderating role of executive control and readiness to change on the relationship between alcohol use and cognitive biases in light and problematic drinkers with and without mild to borderline intellectual disability (MBID). Participants (N = 112) performed the visual dot probe task to measure the strength of the cognitive biases. Executive control was measured using two computerised tasks for working memory capacity (Corsi block-tapping task) and inhibitory control (Go/No-go task). Readiness to change was measured using the Readiness to Change Questionnaire. No cognitive biases or executive dysfunctions were found in problematic drinkers. Working memory capacity and inhibitory control were impaired among individuals with MBID, irrespective of severity of alcohol use-related problems. Executive control and readiness to change did not moderate the relationship between alcohol use and cognitive biases. The results fail to support the dual-process models of addiction, but results need to be treated with caution given the problematic psychometric qualities of the visual dot probe task. Implementing a neurocognitive assessment and protocols in the treatment of substance use disorders seems premature. © 2016 John Wiley & Sons Ltd.

A Generalized-Compliant-Motion Primitive

NASA Technical Reports Server (NTRS)

Backes, Paul G.

1993-01-01

Computer program bridges gap between planning and execution of compliant robotic motions developed and installed in control system of telerobot. Called "generalized-compliant-motion primitive," one of several task-execution-primitive computer programs, which receives commands from higher-level task-planning programs and executes commands by generating required trajectories and applying appropriate control laws. Program comprises four parts corresponding to nominal motion, compliant motion, ending motion, and monitoring. Written in C language.

Goal management training of executive functions in patients with spina bifida: a randomized controlled trial.

PubMed

Stubberud, Jan; Langenbahn, Donna; Levine, Brian; Stanghelle, Johan; Schanke, Anne-Kristine

2013-07-01

Executive dysfunction causes significant real-life disability for patients with spina bifida (SB). However, no previous research has been directed toward the amelioration of executive functioning deficits amongst persons with SB. Goal Management Training (GMT) is a compensatory cognitive rehabilitation approach, addressing underlying deficits in sustained attention to improve executive function. GMT has received empirical support in studies of other patient groups. The purpose of the present study was to determine the efficacy of GMT in treating subjects with SB, using inpatient intervention periods. We hypothesized post-intervention changes in scores on neuropsychological measures to reflect improved attentional control, including sustained attention and inhibitory control. Thirty-eight adult subjects with SB were included in this randomized controlled trial. Inclusion was based upon the presence of executive functioning complaints. Experimental subjects (n = 24) received 21 hr of GMT, with efficacy of GMT being compared to results of subjects in a wait-list condition (n = 14). All subjects were assessed at baseline, post-intervention, and at 6-month follow-up. Findings indicated superior effects of GMT on domain-specific neuropsychological measures and on a functional "real-life" measure, all lasting at least 6 months post-treatment. These results show that deficits in executive functioning can be ameliorated in patients with congenital brain dysfunction.

The relationship of theory of mind and executive functions to symptom type and severity in children with autism.

PubMed

Joseph, Robert M; Tager-Flusberg, Helen

2004-01-01

Although neurocognitive impairments in theory of mind and in executive functions have both been hypothesized to play a causal role in autism, there has been little research investigating the explanatory power of these impairments with regard to autistic symptomatology. The present study examined the degree to which individual differences in theory of mind and executive functions could explain variations in the severity of autism symptoms. Participants included 31 verbal, school-aged children with autism who were administered a battery of tests assessing the understanding of mental states (knowledge and false belief) and executive control skills (working memory, combined working memory and inhibitory control, and planning) and who were behaviorally evaluated for autism severity in the three core symptom domains. Whereas theory of mind and executive control abilities explained the significant variance beyond that accounted for by language level in communication symptoms, neither explained the significant variance in reciprocal social interaction or repetitive behaviors symptoms. These findings are discussed in terms of a proposed distinction between higher level, cognitive-linguistic aspects of theory of mind and related executive control skills, and more fundamental social-perceptual processes involved in the apprehension of mental state information conveyed through eyes, faces, and voices, which may be more closely linked to autistic deficits in social reciprocity.

Design and control of a macro-micro robot for precise force applications

NASA Technical Reports Server (NTRS)

Wang, Yulun; Mangaser, Amante; Laby, Keith; Jordan, Steve; Wilson, Jeff

1993-01-01

Creating a robot which can delicately interact with its environment has been the goal of much research. Primarily two difficulties have made this goal hard to attain. The execution of control strategies which enable precise force manipulations are difficult to implement in real time because such algorithms have been too computationally complex for available controllers. Also, a robot mechanism which can quickly and precisely execute a force command is difficult to design. Actuation joints must be sufficiently stiff, frictionless, and lightweight so that desired torques can be accurately applied. This paper describes a robotic system which is capable of delicate manipulations. A modular high-performance multiprocessor control system was designed to provide sufficient compute power for executing advanced control methods. An 8 degree of freedom macro-micro mechanism was constructed to enable accurate tip forces. Control algorithms based on the impedance control method were derived, coded, and load balanced for maximum execution speed on the multiprocessor system. Delicate force tasks such as polishing, finishing, cleaning, and deburring, are the target applications of the robot.

Lateralization of spatial information processing in response monitoring

PubMed Central

Stock, Ann-Kathrin; Beste, Christian

2014-01-01

The current study aims at identifying how lateralized multisensory spatial information processing affects response monitoring and action control. In a previous study, we investigated multimodal sensory integration in response monitoring processes using a Simon task. Behavioral and neurophysiologic results suggested that different aspects of response monitoring are asymmetrically and independently allocated to the hemispheres: while efference-copy-based information on the motor execution of the task is further processed in the hemisphere that originally generated the motor command, proprioception-based spatial information is processed in the hemisphere contralateral to the effector. Hence, crossing hands (entering a “foreign” spatial hemifield) yielded an augmented bilateral activation during response monitoring since these two kinds of information were processed in opposing hemispheres. Because the traditional Simon task does not provide the possibility to investigate which aspect of the spatial configuration leads to the observed hemispheric allocation, we introduced a new “double crossed” condition that allows for the dissociation of internal/physiological and external/physical influences on response monitoring processes. Comparing behavioral and neurophysiologic measures of this new condition to those of the traditional Simon task setup, we could demonstrate that the egocentric representation of the physiological effector's spatial location accounts for the observed lateralization of spatial information in action control. The finding that the location of the physical effector had a very small influence on response monitoring measures suggests that this aspect is either less important and/or processed in different brain areas than egocentric physiological information. PMID:24550855

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

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.

Autonomic Cardiovascular Control and Executive Function in Chronic Hypotension.

PubMed

Duschek, Stefan; Hoffmann, Alexandra; Reyes Del Paso, Gustavo A; Ettinger, Ulrich

2017-06-01

Chronic low blood pressure (hypotension) is characterized by complaints such as fatigue, reduced drive, dizziness, and cold limbs. Additionally, deficits in attention and memory have been observed. Autonomic dysregulation is considered to be involved in the origin of this condition. The study explored autonomic cardiovascular control in the context of higher cognitive processing (executive function) in hypotension. Hemodynamic recordings were performed in 40 hypotensive and 40 normotensive participants during execution of four classical executive function tasks (number-letter task, n-back task, continuous performance test, and flanker task). Parameters of cardiac sympathetic control, i.e., stroke volume, cardiac output, pre-ejection period, total peripheral resistance, and parasympathetic control, i.e., respiratory sinus arrhythmia and baroreflex sensitivity, were obtained. The hypotensive group exhibited lower stroke volume and cardiac output, as well as higher pre-ejection period and baroreflex sensitivity during task execution. Increased error rates in hypotensive individuals were observed in the n-back and flanker tasks. In the total sample, there were positive correlations of error rates with pre-ejection period, baroreflex sensitivity and respiratory sinus arrhythmia, and negative correlations with cardiac output. Group differences in stroke volume, cardiac output, and pre-ejection period suggest diminished beta-adrenergic myocardial drive during executive function processing in hypotension, in addition to increased baroreflex function. Although further research is warranted to quantify the extent of executive function impairment in hypotension, the results from correlation analysis add evidence to the notion that higher sympathetic inotropic influences and reduced parasympathetic cardiac influences are accompanied by better cognitive performance.

Stop feeling: inhibition of emotional interference following stop-signal trials.

PubMed

Kalanthroff, Eyal; Cohen, Noga; Henik, Avishai

2013-01-01

Although a great deal of literature has been dedicated to the mutual links between emotion and the selective attention component of executive control, there is very little data regarding the links between emotion and the inhibitory component of executive control. In the current study we employed an emotional stop-signal task in order to examine whether emotion modulates and is modulated by inhibitory control. Results replicated previous findings showing reduced inhibitory control [longer stop-signal reaction time (SSRT)] following negative, compared to neutral pictures. Most importantly, results show decreased emotional interference following stop-signal trials. These results show that the inhibitory control component of executive control can serve to decrease emotional effects. We suggest that inhibitory control and emotion have a two-way connection in which emotion disrupts inhibitory control and activation of inhibitory control disrupts emotion.

Mutism and amnesia following high-voltage electrical injury: psychogenic symptomatology triggered by organic dysfunction?

PubMed

Mishra, Nishant K; Russmann, Heike; Granziera, Cristina; Maeder, Philippe; Annoni, Jean-Marie

2011-01-01

Mutism and dense retrograde amnesia are found both in organic and dissociative contexts. Moreover, dissociative symptoms may be modulated by right prefrontal activity. A single case, M.R., developed left hemiparesis, mutism and retrograde amnesia after a high-voltage electric shock without evidence of lasting brain lesions. M.R. suddenly recovered from his mutism following a mild brain trauma 2 years later. M.R.'s neuropsychological pattern and anatomoclinical correlations were studied through (i) language and memory assessment to characterize his deficits, (ii) functional neuroimaging during a standard language paradigm, and (iii) assessment of frontal and left insular connectivity through diffusion tractography imaging and transcranial magnetic stimulation. A control evaluation was repeated after recovery. M.R. recovered from the left hemiparesis within 90 days of the accident, which indicated a transient right brain impairment. One year later, neurobehavioral, language and memory evaluations strongly suggested a dissociative component in the mutism and retrograde amnesia. Investigations (including MRI, fMRI, diffusion tensor imaging, EEG and r-TMS) were normal. Twenty-seven months after the electrical injury, M.R. had a very mild head injury which was followed by a rapid recovery of speech. However, the retrograde amnesia persisted. This case indicates an interaction of both organic and dissociative mechanisms in order to explain the patient's symptoms. The study also illustrates dissociation in the time course of the two different dissociative symptoms in the same patient. Copyright © 2011 S. Karger AG, Basel.

Dissociation of VE-PTP from VE-cadherin is required for leukocyte extravasation and for VEGF-induced vascular permeability in vivo

PubMed Central

Broermann, Andre; Winderlich, Mark; Block, Helena; Frye, Maike; Rossaint, Jan; Zarbock, Alexander; Cagna, Giuseppe; Linnepe, Ruth; Schulte, Dörte; Nottebaum, Astrid Fee

2011-01-01

We have recently shown that vascular endothelial protein tyrosine phosphatase (VE-PTP), an endothelial membrane protein, associates with VE-cadherin and is required for optimal VE-cadherin function and endothelial cell contact integrity. The dissociation of VE-PTP from VE-cadherin is triggered by vascular endothelial growth factor (VEGF) and by the binding of leukocytes to endothelial cells in vitro, suggesting that this dissociation is a prerequisite for the destabilization of endothelial cell contacts. Here, we show that VE-cadherin/VE-PTP dissociation also occurs in vivo in response to LPS stimulation of the lung or systemic VEGF stimulation. To show that this dissociation is indeed necessary in vivo for leukocyte extravasation and VEGF-induced vascular permeability, we generated knock-in mice expressing the fusion proteins VE-cadherin-FK 506 binding protein and VE-PTP-FRB* under the control of the endogenous VE-cadherin promoter, thus replacing endogenous VE-cadherin. The additional domains in both fusion proteins allow the heterodimeric complex to be stabilized by a chemical compound (rapalog). We found that intravenous application of the rapalog strongly inhibited VEGF-induced (skin) and LPS-induced (lung) vascular permeability and inhibited neutrophil extravasation in the IL-1β inflamed cremaster and the LPS-inflamed lung. We conclude that the dissociation of VE-PTP from VE-cadherin is indeed required in vivo for the opening of endothelial cell contacts during induction of vascular permeability and leukocyte extravasation. PMID:22025303

Chemistry at molecular junctions: Rotation and dissociation of O2 on the Ag(110) surface induced by a scanning tunneling microscope.

PubMed

Roy, Sharani; Mujica, Vladimiro; Ratner, Mark A

2013-08-21

The scanning tunneling microscope (STM) is a fascinating tool used to perform chemical processes at the single-molecule level, including bond formation, bond breaking, and even chemical reactions. Hahn and Ho [J. Chem. Phys. 123, 214702 (2005)] performed controlled rotations and dissociations of single O2 molecules chemisorbed on the Ag(110) surface at precise bias voltages using STM. These threshold voltages were dependent on the direction of the bias voltage and the initial orientation of the chemisorbed molecule. They also observed an interesting voltage-direction-dependent and orientation-dependent pathway selectivity suggestive of mode-selective chemistry at molecular junctions, such that in one case the molecule underwent direct dissociation, whereas in the other case it underwent rotation-mediated dissociation. We present a detailed, first-principles-based theoretical study to investigate the mechanism of the tunneling-induced O2 dynamics, including the origin of the observed threshold voltages, the pathway dependence, and the rate of O2 dissociation. Results show a direct correspondence between the observed threshold voltage for a process and the activation energy for that process. The pathway selectivity arises from a competition between the voltage-modified barrier heights for rotation and dissociation, and the coupling strength of the tunneling electrons to the rotational and vibrational modes of the adsorbed molecule. Finally, we explore the "dipole" and "resonance" mechanisms of inelastic electron tunneling to elucidate the energy transfer between the tunneling electrons and chemisorbed O2.

48 CFR 434.004 - Acquisition strategy.

Code of Federal Regulations, 2010 CFR

2010-10-01

....004 Section 434.004 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE SPECIAL... manager will develop, in coordination with the Acquisition Executive or Major Information Technology... approval of the Acquisition Executive or Major Information Technology Systems Executive, a project control...

Intelligent Rover Execution for Detecting Life in the Atacama Desert

NASA Technical Reports Server (NTRS)

Baskaran, Vijayakumar; Muscettola, Nicola; Rijsman, David; Plaunt, Chris; Fry, Chuck

2006-01-01

On-board supervisory execution is crucial for the deployment of more capable and autonomous remote explorers. Planetary science is considering robotic explorers operating for long periods of time without ground supervision while interacting with a changing and often hostile environment. Effective and robust operations require on-board supervisory control with a high level of awareness of the principles of functioning of the environment and of the numerous internal subsystems that need to be coordinated. We describe an on-board rover executive that was deployed on a rover as past of the "Limits of Life in the Atacama Desert (LITA)" field campaign sponsored by the NASA ASTEP program. The executive was built using the Intelligent Distributed Execution Architecture (IDEA), an execution framework that uses model-based and plan-based supervisory control of its fundamental computational paradigm. We present the results of the third field experiment conducted in the Atacama desert (Chile) in August - October 2005.

Estimating the executive demands of a one-back choice reaction time task by means of the selective interference paradigm.

PubMed

Szmalec, Arnaud; Vandierendonck, André

2007-08-01

The present study proposes a new executive task, the one-back choice reaction time (RT) task, and implements the selective interference paradigm to estimate the executive demands of the processing components involved in this task. Based on the similarities between a one-back choice RT task and the n-back updating task, it was hypothesized that one-back delaying of a choice reaction involves executive control. In three experiments, framed within Baddeley's (1986) working-memory model, a one-back choice RT task, a choice RT task, articulatory suppression, and matrix tapping were performed concurrently with primary tasks involving verbal, visuospatial, and executive processing. The results demonstrate that one-back delaying of a choice reaction interferes with tasks requiring executive control, while the potential interference at the level of the verbal or visuospatial working memory slave systems remains minimal.

Using Hypnotic Suggestion to Model Loss of Control and Awareness of Movements: An Exploratory fMRI Study

PubMed Central

Oakley, David A.; Bell, Vaughan; Koppel, Cristina; Mehta, Mitul A.; Halligan, Peter W.

2013-01-01

The feeling of voluntary control and awareness of movement is fundamental to our notions of selfhood and responsibility for actions, yet can be lost in neuropsychiatric syndromes (e.g. delusions of control, non-epileptic seizures) and culturally influenced dissociative states (e.g. attributions of spirit possession). The brain processes involved remain poorly understood. We used suggestion and functional magnetic resonance imaging (fMRI) to investigate loss of control and awareness of right hand movements in 15 highly hypnotically suggestible subjects. Loss of perceived control of movements was associated with reduced connectivity between supplementary motor area (SMA) and motor regions. Reduced awareness of involuntary movements was associated with less activation in parietal cortices (BA 7, BA 40) and insula. Collectively these results suggest that the sense of voluntary control of movement may critically depend on the functional coupling of SMA with motor systems, and provide a potential neural basis for the narrowing of awareness reported in pathological and culturally influenced dissociative phenomena. PMID:24205198

Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough

USGS Publications Warehouse

Santamarina, J.C.; Dai, Shifeng; Terzariol, M.; Jang, Jeonghwan; Waite, William F.; Winters, William J.; Nagao, J.; Yoneda, J.; Konno, Y.; Fujii, T.; Suzuki, K.

2015-01-01

Natural hydrate-bearing sediments from the Nankai Trough, offshore Japan, were studied using the Pressure Core Characterization Tools (PCCTs) to obtain geomechanical, hydrological, electrical, and biological properties under in situ pressure, temperature, and restored effective stress conditions. Measurement results, combined with index-property data and analytical physics-based models, provide unique insight into hydrate-bearing sediments in situ. Tested cores contain some silty-sands, but are predominantly sandy- and clayey-silts. Hydrate saturations Sh range from 0.15 to 0.74, with significant concentrations in the silty-sands. Wave velocity and flexible-wall permeameter measurements on never-depressurized pressure-core sediments suggest hydrates in the coarser-grained zones, the silty-sands where Sh exceeds 0.4, contribute to soil-skeletal stability and are load-bearing. In the sandy- and clayey-silts, where Sh < 0.4, the state of effective stress and stress history are significant factors determining sediment stiffness. Controlled depressurization tests show that hydrate dissociation occurs too quickly to maintain thermodynamic equilibrium, and pressure–temperature conditions track the hydrate stability boundary in pure-water, rather than that in seawater, in spite of both the in situ pore water and the water used to maintain specimen pore pressure prior to dissociation being saline. Hydrate dissociation accompanied with fines migration caused up to 2.4% vertical strain contraction. The first-ever direct shear measurements on never-depressurized pressure-core specimens show hydrate-bearing sediments have higher sediment strength and peak friction angle than post-dissociation sediments, but the residual friction angle remains the same in both cases. Permeability measurements made before and after hydrate dissociation demonstrate that water permeability increases after dissociation, but the gain is limited by the transition from hydrate saturation before dissociation to gas saturation after dissociation. In a proof-of-concept study, sediment microbial communities were successfully extracted and stored under high-pressure, anoxic conditions. Depressurized samples of these extractions were incubated in air, where microbes exhibited temperature-dependent growth rates.

Using developmental cognitive neuroscience to study behavioral and attentional control.

PubMed

Astle, Duncan E; Scerif, Gaia

2009-03-01

Adult cognitive neuroscience employs a wide variety of techniques to investigate a broad range of behavioral and cognitive functions. One prominent area of study is that of executive control, complemented by a smaller but growing literature exploring the developmental cognitive neuroscience of executive control. To date this approach has often compared children with specific developmental disorders, such as ADHD and ASD, with typically developing controls. Whilst these comparisons have done much to advance our understanding of the neural markers that underpin behavioral difficulties at specific time-points in development, we contend that they should leave developmental cognitive neuroscientists wanting. Studying the neural correlates of typical changes in executive control in their own right can reveal how different neural mechanisms characteristic of the adult end-state emerge, and it can therefore inform the adult cognitive neuroscience of executive control itself. The current review addresses the extent to which developmentalists and adult cognitive neuroscientists have tapped this common ground. Some very elegant investigations illustrate how seemingly common processes in adulthood present as separable in childhood, on the basis of their distinctive developmental trajectories. These demonstrations have implications not only for an understanding of changing behavior from infancy through childhood and adolescence into adulthood, but, moreover, for our grasp of the adult end-state per se. We contend that, if used appropriately, developmental cognitive neuroscience could enable us to construct a more mechanistic account of executive control.

Automatic Overset Grid Generation with Heuristic Feedback Control

NASA Technical Reports Server (NTRS)

Robinson, Peter I.

2001-01-01

An advancing front grid generation system for structured Overset grids is presented which automatically modifies Overset structured surface grids and control lines until user-specified grid qualities are achieved. The system is demonstrated on two examples: the first refines a space shuttle fuselage control line until global truncation error is achieved; the second advances, from control lines, the space shuttle orbiter fuselage top and fuselage side surface grids until proper overlap is achieved. Surface grids are generated in minutes for complex geometries. The system is implemented as a heuristic feedback control (HFC) expert system which iteratively modifies the input specifications for Overset control line and surface grids. It is developed as an extension of modern control theory, production rules systems and subsumption architectures. The methodology provides benefits over the full knowledge lifecycle of an expert system for knowledge acquisition, knowledge representation, and knowledge execution. The vector/matrix framework of modern control theory systematically acquires and represents expert system knowledge. Missing matrix elements imply missing expert knowledge. The execution of the expert system knowledge is performed through symbolic execution of the matrix algebra equations of modern control theory. The dot product operation of matrix algebra is generalized for heuristic symbolic terms. Constant time execution is guaranteed.

Increased Executive Functioning, Attention, and Cortical Thickness in White-Collar Criminals

PubMed Central

Raine, Adrian; Laufer, William S.; Yang, Yaling; Narr, Katherine L.; Thompson, Paul; Toga, Arthur W.

2011-01-01

Very little is known on white collar crime and how it differs to other forms of offending. This study tests the hypothesis that white collar criminals have better executive functioning, enhanced information processing, and structural brain superiorities compared to offender controls. Using a case-control design, executive functioning, orienting, and cortical thickness was assessed in 21 white collar criminals matched with 21 controls on age, gender, ethnicity, and general level of criminal offending. White collar criminals had significantly better executive functioning, increased electrodermal orienting, increased arousal, and increased cortical gray matter thickness in the ventromedial prefrontal cortex, inferior frontal gyrus, somatosensory cortex, and the temporal-parietal junction compared to controls. Results, while initial, constitute the first findings on neurobiological characteristics of white-collar criminals It is hypothesized that white collar criminals have information-processing and brain superiorities that give them an advantage in perpetrating criminal offenses in occupational settings. PMID:22002326

Increased executive functioning, attention, and cortical thickness in white-collar criminals.

PubMed

Raine, Adrian; Laufer, William S; Yang, Yaling; Narr, Katherine L; Thompson, Paul; Toga, Arthur W

2012-12-01

Very little is known on white-collar crime and how it differs to other forms of offending. This study tests the hypothesis that white-collar criminals have better executive functioning, enhanced information processing, and structural brain superiorities compared with offender controls. Using a case-control design, executive functioning, orienting, and cortical thickness was assessed in 21 white-collar criminals matched with 21 controls on age, gender, ethnicity, and general level of criminal offending. White-collar criminals had significantly better executive functioning, increased electrodermal orienting, increased arousal, and increased cortical gray matter thickness in the ventromedial prefrontal cortex, inferior frontal gyrus, somatosensory cortex, and the temporal-parietal junction compared with controls. Results, while initial, constitute the first findings on neurobiological characteristics of white-collar criminals. It is hypothesized that white-collar criminals have information-processing and brain superiorities that give them an advantage in perpetrating criminal offenses in occupational settings. Copyright © 2011 Wiley Periodicals, Inc.

Impact of the Cognitive-Functional (Cog-Fun) Intervention on Executive Functions and Participation Among Children With Attention Deficit Hyperactivity Disorder: A Randomized Controlled Trial.

PubMed

Hahn-Markowitz, Jeri; Berger, Itai; Manor, Iris; Maeir, Adina

We examined the effect of the Cognitive-Functional (Cog-Fun) occupational therapy intervention on executive functions and participation among children with attention deficit hyperactivity disorder (ADHD). We used a randomized, controlled study with a crossover design. One hundred and seven children age 7-10 yr diagnosed with ADHD were allocated to treatment or wait-list control group. The control group received treatment after a 3-mo wait. Outcome measures included the Behavior Rating Inventory of Executive Function (BRIEF) and the Canadian Occupational Performance Measure (COPM). Significant improvements were found on both the BRIEF and COPM after intervention with large treatment effects. Before crossover, significant Time × Group interactions were found on the BRIEF. This study supports the effectiveness of the Cog-Fun intervention in improving executive functions and participation among children with ADHD. Copyright © 2017 by the American Occupational Therapy Association, Inc.

Acute stress affects prospective memory functions via associative memory processes.

PubMed

Szőllősi, Ágnes; Pajkossy, Péter; Demeter, Gyula; Kéri, Szabolcs; Racsmány, Mihály

2018-01-01

Recent findings suggest that acute stress can improve the execution of delayed intentions (prospective memory, PM). However, it is unclear whether this improvement can be explained by altered executive control processes or by altered associative memory functioning. To investigate this issue, we used physical-psychosocial stressors to induce acute stress in laboratory settings. Then participants completed event- and time-based PM tasks requiring the different contribution of control processes and a control task (letter fluency) frequently used to measure executive functions. According to our results, acute stress had no impact on ongoing task performance, time-based PM, and verbal fluency, whereas it enhanced event-based PM as measured by response speed for the prospective cues. Our findings indicate that, here, acute stress did not affect executive control processes. We suggest that stress affected event-based PM via associative memory processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Power-Aware Compiler Controllable Chip Multiprocessor

NASA Astrophysics Data System (ADS)

Shikano, Hiroaki; Shirako, Jun; Wada, Yasutaka; Kimura, Keiji; Kasahara, Hironori

A power-aware compiler controllable chip multiprocessor (CMP) is presented and its performance and power consumption are evaluated with the optimally scheduled advanced multiprocessor (OSCAR) parallelizing compiler. The CMP is equipped with power control registers that change clock frequency and power supply voltage to functional units including processor cores, memories, and an interconnection network. The OSCAR compiler carries out coarse-grain task parallelization of programs and reduces power consumption using architectural power control support and the compiler's power saving scheme. The performance evaluation shows that MPEG-2 encoding on the proposed CMP with four CPUs results in 82.6% power reduction in real-time execution mode with a deadline constraint on its sequential execution time. Furthermore, MP3 encoding on a heterogeneous CMP with four CPUs and four accelerators results in 53.9% power reduction at 21.1-fold speed-up in performance against its sequential execution in the fastest execution mode.

Meta-cognitive processes in executive control development: The case of reactive and proactive control

PubMed Central

Chevalier, Nicolas; Martis, Shaina Bailey; Curran, Tim; Munakata, Yuko

2015-01-01

Young children engage cognitive control reactively in response to events, rather than proactively preparing for events. Such limitations in executive control have been explained in terms of fundamental constraints on children’s cognitive capacities. Alternatively, young children might be capable of proactive control but differ from older children in their meta-cognitive decisions regarding when to engage proactive control. We examined these possibilities in three conditions of a task-switching paradigm, varying in whether task cues were available before or after target onset. Reaction times, ERPs, and pupil dilation showed that 5-year-olds did engage in advance preparation, a critical aspect of proactive control, but only when reactive control was made more difficult, whereas 10-year-olds engaged proactive control whenever possible. These findings highlight meta-cognitive processes in children’s cognitive control, an understudied aspect of executive control development. PMID:25603026

Dissociation Between Working Memory Performance and Proactive Interference Control in Post-Traumatic Stress Disorder

PubMed Central

Swick, Diane; Cayton, Julien; Ashley, Victoria; Turken, And U.

2017-01-01

Deficits in working memory (WM) and cognitive control processes have been reported in post-traumatic stress disorder (PTSD), in addition to clinical symptoms such as hypervigilance, re-experiencing, and avoidance of trauma reminders. Given the uncontrollable nature of intrusive memories, an important question is whether PTSD is associated with altered control of interference in WM. Some studies also suggest that episodic memory shows a material-specific dissociation in PTSD, with greater impairments in verbal memory and relative sparing of nonverbal memory. It is unclear whether this dissociation applies to WM, as no studies have used identical task parameters across material. Here we tested 29 combat Veterans with PTSD and 29 age-matched control Veterans on a recent probes WM task with words and visual patterns in separate blocks. Participants studied four-item sets, followed by a probe stimulus that had been presented in the previous set (recent probe) or not (nonrecent probe). Participants with PTSD made more errors than controls, and this decrement was similar for verbal and visual stimuli. Proactive interference from items recently presented, but no longer relevant, was not significantly different in the PTSD group and showed no relationship to re-experiencing symptom severity. These results demonstrate that PTSD is not reliably associated with increased intrusions of irrelevant representations into WM when non-emotional stimuli are used. Future studies that use trauma-related material may provide insight into the flashbacks and intrusive thoughts that plague those with PTSD. PMID:28077328

Dissociation between working memory performance and proactive interference control in post-traumatic stress disorder.

PubMed

Swick, Diane; Cayton, Julien; Ashley, Victoria; Turken, And U

2017-02-01

Deficits in working memory (WM) and cognitive control processes have been reported in post-traumatic stress disorder (PTSD), in addition to clinical symptoms such as hypervigilance, re-experiencing, and avoidance of trauma reminders. Given the uncontrollable nature of intrusive memories, an important question is whether PTSD is associated with altered control of interference in WM. Some studies also suggest that episodic memory shows a material-specific dissociation in PTSD, with greater impairments in verbal memory and relative sparing of nonverbal memory. It is unclear whether this dissociation applies to WM, as no studies have used identical task parameters across material. Here we tested 29 combat Veterans with PTSD and 29 age-matched control Veterans on a recent probes WM task with words and visual patterns in separate blocks. Participants studied four-item sets, followed by a probe stimulus that had been presented in the previous set (recent probe) or not (nonrecent probe). Participants with PTSD made more errors than controls, and this decrement was similar for verbal and visual stimuli. Proactive interference from items recently presented, but no longer relevant, was not significantly different in the PTSD group and showed no relationship to re-experiencing symptom severity. These results demonstrate that PTSD is not reliably associated with increased intrusions of irrelevant representations into WM when non-emotional stimuli are used. Future studies that use trauma-related material may provide insight into the flashbacks and intrusive thoughts that plague those with PTSD. Published by Elsevier Ltd.

21 CFR 1305.12 - Procedure for executing DEA Forms 222.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Procedure for executing DEA Forms 222. 1305.12... I AND II CONTROLLED SUBSTANCES DEA Form 222 § 1305.12 Procedure for executing DEA Forms 222. (a) A purchaser must prepare and execute a DEA Form 222 simultaneously in triplicate by means of interleaved...

21 CFR 1305.12 - Procedure for executing DEA Forms 222.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Procedure for executing DEA Forms 222. 1305.12... I AND II CONTROLLED SUBSTANCES DEA Form 222 § 1305.12 Procedure for executing DEA Forms 222. (a) A purchaser must prepare and execute a DEA Form 222 simultaneously in triplicate by means of interleaved...

A 24-Week Multi-Modality Exercise Program Improves Executive Control in Older Adults with a Self-Reported Cognitive Complaint: Evidence from the Antisaccade Task.

PubMed

Heath, Matthew; Shellington, Erin; Titheridge, Sam; Gill, Dawn P; Petrella, Robert J

2017-01-01

Exercise programs involving aerobic and resistance training (i.e., multiple-modality) have shown promise in improving cognition and executive control in older adults at risk, or experiencing, cognitive decline. It is, however, unclear whether cognitive training within a multiple-modality program elicits an additive benefit to executive/cognitive processes. This is an important question to resolve in order to identify optimal training programs that delay, or ameliorate, executive deficits in persons at risk for further cognitive decline. In the present study, individuals with a self-reported cognitive complaint (SCC) participated in a 24-week multiple-modality (i.e., the M2 group) exercise intervention program. In addition, a separate group of individuals with a SCC completed the same aerobic and resistance training as the M2 group but also completed a cognitive-based stepping task (i.e., multiple-modality, mind-motor intervention: M4 group). Notably, pre- and post-intervention executive control was examined via the antisaccade task (i.e., eye movement mirror-symmetrical to a target). Antisaccades are an ideal tool for the study of individuals with subtle executive deficits because of its hands- and language-free nature and because the task's neural mechanisms are linked to neuropathology in cognitive decline (i.e., prefrontal cortex). Results showed that M2 and M4 group antisaccade reaction times reliably decreased from pre- to post-intervention and the magnitude of the decrease was consistent across groups. Thus, multi-modality exercise training improved executive performance in persons with a SCC independent of mind-motor training. Accordingly, we propose that multiple-modality training provides a sufficient intervention to improve executive control in persons with a SCC.

Individual differences in the executive control of attention, memory, and thought, and their associations with schizotypy.

PubMed

Kane, Michael J; Meier, Matt E; Smeekens, Bridget A; Gross, Georgina M; Chun, Charlotte A; Silvia, Paul J; Kwapil, Thomas R

2016-08-01

A large correlational study took a latent-variable approach to the generality of executive control by testing the individual-differences structure of executive-attention capabilities and assessing their prediction of schizotypy, a multidimensional construct (with negative, positive, disorganized, and paranoid factors) conveying risk for schizophrenia. Although schizophrenia is convincingly linked to executive deficits, the schizotypy literature is equivocal. Subjects completed tasks of working memory capacity (WMC), attention restraint (inhibiting prepotent responses), and attention constraint (focusing visual attention amid distractors), the latter 2 in an effort to fractionate the "inhibition" construct. We also assessed mind-wandering propensity (via in-task thought probes) and coefficient of variation in response times (RT CoV) from several tasks as more novel indices of executive attention. WMC, attention restraint, attention constraint, mind wandering, and RT CoV were correlated but separable constructs, indicating some distinctions among "attention control" abilities; WMC correlated more strongly with attentional restraint than constraint, and mind wandering correlated more strongly with attentional restraint, attentional constraint, and RT CoV than with WMC. Across structural models, no executive construct predicted negative schizotypy and only mind wandering and RT CoV consistently (but modestly) predicted positive, disorganized, and paranoid schizotypy; stalwart executive constructs in the schizophrenia literature-WMC and attention restraint-showed little to no predictive power, beyond restraint's prediction of paranoia. Either executive deficits are consequences rather than risk factors for schizophrenia, or executive failures barely precede or precipitate diagnosable schizophrenia symptoms. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Altered fronto-striatal functions in the Gdi1-null mouse model of X-linked Intellectual Disability.

PubMed

Morè, Lorenzo; Künnecke, Basil; Yekhlef, Latefa; Bruns, Andreas; Marte, Antonella; Fedele, Ernesto; Bianchi, Veronica; Taverna, Stefano; Gatti, Silvia; D'Adamo, Patrizia

2017-03-06

RAB-GDP dissociation inhibitor 1 (GDI1) loss-of-function mutations are responsible for a form of non-specific X-linked Intellectual Disability (XLID) where the only clinical feature is cognitive impairment. GDI1 patients are impaired in specific aspects of executive functions and conditioned response, which are controlled by fronto-striatal circuitries. Previous molecular and behavioral characterization of the Gdi1-null mouse revealed alterations in the total number/distribution of hippocampal and cortical synaptic vesicles as well as hippocampal short-term synaptic plasticity, and memory deficits. In this study, we employed cognitive protocols with high translational validity to human condition that target the functionality of cortico-striatal circuitry such as attention and stimulus selection ability with progressive degree of complexity. We previously showed that Gdi1-null mice are impaired in some hippocampus-dependent forms of associative learning assessed by aversive procedures. Here, using appetitive-conditioning procedures we further investigated associative learning deficits sustained by the fronto-striatal system. We report that Gdi1-null mice are impaired in attention and associative learning processes, which are a key part of the cognitive impairment observed in XLID patients. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Functional network connectivity underlying food processing: disturbed salience and visual processing in overweight and obese adults.

PubMed

Kullmann, Stephanie; Pape, Anna-Antonia; Heni, Martin; Ketterer, Caroline; Schick, Fritz; Häring, Hans-Ulrich; Fritsche, Andreas; Preissl, Hubert; Veit, Ralf

2013-05-01

In order to adequately explore the neurobiological basis of eating behavior of humans and their changes with body weight, interactions between brain areas or networks need to be investigated. In the current functional magnetic resonance imaging study, we examined the modulating effects of stimulus category (food vs. nonfood), caloric content of food, and body weight on the time course and functional connectivity of 5 brain networks by means of independent component analysis in healthy lean and overweight/obese adults. These functional networks included motor sensory, default-mode, extrastriate visual, temporal visual association, and salience networks. We found an extensive modulation elicited by food stimuli in the 2 visual and salience networks, with a dissociable pattern in the time course and functional connectivity between lean and overweight/obese subjects. Specifically, only in lean subjects, the temporal visual association network was modulated by the stimulus category and the salience network by caloric content, whereas overweight and obese subjects showed a generalized augmented response in the salience network. Furthermore, overweight/obese subjects showed changes in functional connectivity in networks important for object recognition, motivational salience, and executive control. These alterations could potentially lead to top-down deficiencies driving the overconsumption of food in the obese population.

Clinical assessment of motor function: a processes oriented instrument based on a speed-accuracy trade-off paradigm.

PubMed

Christe, Blaise; Burkhard, Pierre R; Pegna, Alan J; Mayer, Eugene; Hauert, Claude-Alain

2007-01-01

In this study, we developed a digitizing tablet-based instrument for the clinical assessment of human voluntary movements targeting motor processes of planning, programming and execution. The tool was used to investigate an adaptation of Fitts' reciprocal tapping task [10], comprising four conditions, each of them modulated by three indices of difficulty related to the amplitude of movement required. Temporal, spatial and sequential constraints underlying the various conditions allowed the intricate motor processes to be dissociated. Data obtained from a group of elderly healthy subjects (N=50) were in agreement with the literature on motor control, in the temporal and spatial domains. Speed constraints generated gains in the temporal domain and costs in the spatial one, while spatial constraints generated gain in the spatial domain and costs in the temporal one; finally, sequential constraints revealed the integrative nature of the cognitive operations involved in motor production. This versatile instrument proved capable of providing quantitative, accurate and sensitive measures of the various processes sustaining voluntary movement in healthy subjects. Altogether, analyses performed in this study generated a theoretical framework and reference data which could be used in the future for the clinical assessment of patients with various movement disorders, in particular Parkinson's disease.

Neural Correlates of Consumer Buying Motivations: A 7T functional Magnetic Resonance Imaging (fMRI) Study

PubMed Central

Goodman, Adam M.; Wang, Yun; Kwon, Wi-Suk; Byun, Sang-Eun; Katz, Jeffrey S.; Deshpande, Gopikrishna

2017-01-01

Consumer buying motivations can be distinguished into three categories: functional, experiential, or symbolic motivations (Keller, 1993). Although prior neuroimaging studies have examined the neural substrates which enable these motivations, direct comparisons between these three types of consumer motivations have yet to be made. In the current study, we used 7 Tesla (7T) functional magnetic resonance imaging (fMRI) to assess the neural correlates of each motivation by instructing participants to view common consumer goods while emphasizing either functional, experiential, or symbolic values of these products. The results demonstrated mostly consistent activations between symbolic and experiential motivations. Although, these motivations differed in that symbolic motivation was associated with medial frontal gyrus (MFG) activation, whereas experiential motivation was associated with posterior cingulate cortex (PCC) activation. Functional motivation was associated with dorsolateral prefrontal cortex (DLPFC) activation, as compared to other motivations. These findings provide a neural basis for how symbolic and experiential motivations may be similar, yet different in subtle ways. Furthermore, the dissociation of functional motivation within the DLPFC supports the notion that this motivation relies on executive function processes relatively more than hedonic motivation. These findings provide a better understanding of the underlying neural functioning which may contribute to poor self-control choices. PMID:28959182

ACC Neuro-over-Connectivity Is Associated with Mathematically Modeled Additional Encoding Operations of Schizophrenia Stroop-Task Performance

PubMed Central

Taylor, Reggie; Théberge, Jean; Williamson, Peter C.; Densmore, Maria; Neufeld, Richard W. J.

2016-01-01

Functional magnetic resonance imaging at 7.0 Tesla was undertaken among Schizophrenia participants (Sz), and clinical (major mood disorder; MDD) and healthy controls (HC), during performance of the Stoop task. Stroop conditions included congruent and incongruent word color items, color-only items, and word-only items. Previous modeling results extended to this most widely used selective-attention task. All groups executed item-encoding operations (subprocesses of the item encoding process) at the same rate (performance accuracy being similarly high throughout), thus displaying like processing capacity; Sz participants, however, employed more subprocesses for item completions than did the MDD participants, who in turn used more subprocesses than the HC group. The reduced efficiency in deploying cognitive-workload capacity among the Sz participants was paralleled by more diffuse neuroconnectivity (Blood-Oxygen-Level-Dependent co-activation) with the anterior cingulate cortex (ACC) (Broadman Area 32), spreading away from this encoding-intensive region; and by less evidence of network dissociation across Stroop conditions. Estimates of cognitive work done to accomplish item completion were greater for the Sz participants, as were estimates of entropy in both the modeled trial-latency distribution, and its associated neuro-circuitry. Findings are held to be symptom and assessment significant, and to have potential implications for clinical intervention. PMID:27695425

When is category specific in Alzheimer's disease?

PubMed

Laws, Keith R; Gale, Tim M; Leeson, Verity C; Crawford, John R

2005-08-01

Mixed findings have emerged concerning whether category-specific disorders occur in Alzheimer's disease. Factors that may contribute to these inconsistencies include: ceiling effects/skewed distributions for control data in some studies; differences in the severity of cognitive deficit in patients; and differences in the type of analysis (in particular, if and how controls are used to analyse single case data). We examined picture naming in Alzheimer's patients and matched elderly healthy normal controls in three experiments. These experiments used stimuli that did and did not produce ceiling effects/skewed data in controls. In Experiment 1, we examined for category effects in individual DAT patients using commonly used analyses for single cases (chi2 and z-scores). The different techniques produced quite different outcomes. In Experiment 2a, we used the same techniques on a different group of patients with similar outcomes. Finally, in Experiment 2b, we examined the same patients but (a) used stimuli that did not produce ceiling effects/skewed distributions in healthy controls, and (b) used statistical methods that did not treat the control sample as a population. We found that ceiling effects in controls may markedly inflate the incidence of dissociations in which living things are differentially impaired and seriously underestimate dissociations in the opposite direction. In addition, methods that treat the control sample as a population led to inflation in the overall number of dissociations detected. These findings have implications for the reliability of category effects previously reported both in Alzheimer patients and in other pathologies. In particular, they suggest that the greater proportion of living than nonliving deficits reported in the literature may be an artifact of the methods used.

Brain Oscillatory Correlates of Altered Executive Functioning in Positive and Negative Symptomatic Schizophrenia Patients and Healthy Controls.

PubMed

Berger, Barbara; Minarik, Tamas; Griesmayr, Birgit; Stelzig-Schoeler, Renate; Aichhorn, Wolfgang; Sauseng, Paul

2016-01-01

Working Memory and executive functioning deficits are core characteristics of patients suffering from schizophrenia. Electrophysiological research indicates that altered patterns of neural oscillatory mechanisms underpinning executive functioning are associated with the psychiatric disorder. Such brain oscillatory changes have been found in local amplitude differences at gamma and theta frequencies in task-specific cortical areas. Moreover, interregional interactions are also disrupted as signified by decreased phase coherence of fronto-posterior theta activity in schizophrenia patients. However, schizophrenia is not a one-dimensional psychiatric disorder but has various forms and expressions. A common distinction is between positive and negative symptomatology but most patients have both negative and positive symptoms to some extent. Here, we examined three groups-healthy controls, predominantly negative, and predominantly positive symptomatic schizophrenia patients-when performing a working memory task with increasing cognitive demand and increasing need for executive control. We analyzed brain oscillatory activity in the three groups separately and investigated how predominant symptomatology might explain differences in brain oscillatory patterns. Our results indicate that differences in task specific fronto-posterior network activity (i.e., executive control network) expressed by interregional phase synchronization are able to account for working memory dysfunctions between groups. Local changes in the theta and gamma frequency range also show differences between patients and healthy controls, and more importantly, between the two patient groups. We conclude that differences in oscillatory brain activation patterns related to executive processing can be an indicator for positive and negative symptomatology in schizophrenia. Furthermore, changes in cognitive and especially executive functioning in patients are expressed by alterations in a task-specific fronto-posterior connectivity even in the absence of behavioral impairment.

Balanced bilingualism and early age of second language acquisition as the underlying mechanisms of a bilingual executive control advantage: why variations in bilingual experiences matter

PubMed Central

Yow, W. Quin; Li, Xiaoqian

2015-01-01

Recent studies revealed inconsistent evidences of a bilingual advantage in executive processing. One potential source of explanation is the multifaceted experience of the bilinguals in these studies. This study seeks to test whether bilinguals who engage in language selection more frequently would perform better in executive control tasks than those bilinguals who engage in language selection less frequently. We examined the influence of the degree of bilingualism (i.e., language proficiency, frequency of use of two languages, and age of second language acquisition) on executive functioning in bilingual young adults using a comprehensive battery of executive control tasks. Seventy-two 18- to 25-years-old English–Mandarin bilinguals performed four computerized executive function (EF) tasks (Stroop, Eriksen flanker, number–letter switching, and n-back task) that measure the EF components: inhibition, mental-set shifting, and information updating and monitoring. Results from multiple regression analyses, structural equation modeling, and bootstrapping supported the positive association between age of second language acquisition and the interference cost in the Stroop task. Most importantly, we found a significant effect of balanced bilingualism (balanced usage of and balanced proficiency in two languages) on the Stroop and number–letter task (mixing cost only), indicating that a more balanced use and a more balanced level of proficiency in two languages resulted in better executive control skills in the adult bilinguals. We did not find any significant effect of bilingualism on flanker or n-back task. These findings provided important insights to the underlying mechanisms of the bilingual cognitive advantage hypothesis, demonstrating that regular experience with extensive practice in controlling attention to their two language systems results in better performance in related EFs such as inhibiting prepotent responses and global set-shifting. PMID:25767451

Balanced bilingualism and early age of second language acquisition as the underlying mechanisms of a bilingual executive control advantage: why variations in bilingual experiences matter.

PubMed

Yow, W Quin; Li, Xiaoqian

2015-01-01

Recent studies revealed inconsistent evidences of a bilingual advantage in executive processing. One potential source of explanation is the multifaceted experience of the bilinguals in these studies. This study seeks to test whether bilinguals who engage in language selection more frequently would perform better in executive control tasks than those bilinguals who engage in language selection less frequently. We examined the influence of the degree of bilingualism (i.e., language proficiency, frequency of use of two languages, and age of second language acquisition) on executive functioning in bilingual young adults using a comprehensive battery of executive control tasks. Seventy-two 18- to 25-years-old English-Mandarin bilinguals performed four computerized executive function (EF) tasks (Stroop, Eriksen flanker, number-letter switching, and n-back task) that measure the EF components: inhibition, mental-set shifting, and information updating and monitoring. Results from multiple regression analyses, structural equation modeling, and bootstrapping supported the positive association between age of second language acquisition and the interference cost in the Stroop task. Most importantly, we found a significant effect of balanced bilingualism (balanced usage of and balanced proficiency in two languages) on the Stroop and number-letter task (mixing cost only), indicating that a more balanced use and a more balanced level of proficiency in two languages resulted in better executive control skills in the adult bilinguals. We did not find any significant effect of bilingualism on flanker or n-back task. These findings provided important insights to the underlying mechanisms of the bilingual cognitive advantage hypothesis, demonstrating that regular experience with extensive practice in controlling attention to their two language systems results in better performance in related EFs such as inhibiting prepotent responses and global set-shifting.

The Role of Executive Functions in Social Cognition among Children with Down Syndrome: Relationship Patterns

PubMed Central

Amadó, Anna; Serrat, Elisabet; Vallès-Majoral, Eduard

2016-01-01

Many studies show a link between social cognition, a set of cognitive and emotional abilities applied to social situations, and executive functions in typical developing children. Children with Down syndrome (DS) show deficits both in social cognition and in some subcomponents of executive functions. However this link has barely been studied in this population. The aim of this study is to investigate the links between social cognition and executive functions among children with DS. We administered a battery of social cognition and executive function tasks (six theory of mind tasks, a test of emotion comprehension, and three executive function tasks) to a group of 30 participants with DS between 4 and 12 years of age. The same tasks were administered to a chronological-age control group and to a control group with the same linguistic development level. Results showed that apart from deficits in social cognition and executive function abilities, children with DS displayed a slight improvement with increasing chronological age and language development in those abilities. Correlational analysis suggested that working memory was the only component that remained constant in the relation patterns of the three groups of participants, being the relation patterns similar among participants with DS and the language development control group. A multiple linear regression showed that working memory explained above 50% of the variability of social cognition in DS participants and in language development control group, whereas in the chronological-age control group this component only explained 31% of the variability. These findings, and specifically the link between working memory and social cognition, are discussed on the basis of their theoretical and practical implications for children with DS. We discuss the possibility to use a working memory training to improve social cognition in this population. PMID:27679588