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Sample records for acoustic startle probes

  1. Habituation of parasympathetic-mediated heart rate responses to recurring acoustic startle

    PubMed Central

    Chen, Kuan-Hua; Aksan, Nazan; Anderson, Steven W.; Grafft, Amanda; Chapleau, Mark W.

    2014-01-01

    Startle habituation is a type of implicit and automatic emotion regulation. Diminished startle habituation is linked to several psychiatric or neurological disorders. Most previous studies quantified startle habituation by assessing skin conductance response (SCR; reflecting sympathetic-mediated sweating), eye-blink reflex, or motor response. The habituation of parasympathetic-mediated heart rate responses to recurrent startle stimuli is not well understood. A variety of methods and metrics have been used to quantify parasympathetic activity and its effects on the heart. We hypothesized that these different measures reflect unique psychological and physiological processes that may habituate differently during repeated startle stimuli. We measured cardiac inter-beat intervals (IBIs) to recurring acoustic startle probes in 75 eight year old children. Eight acoustic stimuli of 500 ms duration were introduced at intervals of 15–25 s. Indices of parasympathetic effect included: (1) the initial rapid decrease in IBI post-startle mediated by parasympathetic inhibition (PI); (2) the subsequent IBI recovery mediated by parasympathetic reactivation (PR); (3) rapid, beat-to-beat heart rate variability (HRV) measured from the first seven IBIs following each startle probe. SCR and motor responses to startle were also measured. Results showed that habituation of PR (IBI recovery and overshoot) and SCRs were rapid and robust. In addition, changes in PR and SCR were significantly correlated. In contrast, habituation of PI (the initial decrease in IBI) was slower and relatively modest. Measurement of rapid HRV provided an index reflecting the combination of PI and PR. We conclude that different measures of parasympathetic-mediated heart rate responses to repeated startle probes habituate in a differential manner. PMID:25477830

  2. Airpuff startle probes: an efficacious and less aversive alternative to white-noise.

    PubMed

    Lissek, Shmuel; Baas, Johanna M P; Pine, Daniel S; Orme, Kaebah; Dvir, Sharone; Nugent, Monique; Rosenberger, Emily; Rawson, Elizabeth; Grillon, Christian

    2005-03-01

    Fear-potentiated startle (FPS) is an increasingly popular psychophysiological method for the objective assessment of fear and anxiety. Studies applying this method often elicit the startle reflex with loud white-noise stimuli. Such intense stimuli may, however, alter psychological processes of interest by creating unintended emotional or attentional artifacts. Additionally, loud acoustic probes may be unsuitable for use with infants, children, the elderly, and those with hearing damage. Past studies have noted robust and reliable startle reflexes elicited by low intensity airpuffs. The current study compares the aversiveness of white-noise (102 dB) and airpuff (3 psi) probes and examines the sensitivity of each probe for the assessment of fear-potentiated startle. Results point to less physiological arousal and self-reported reactivity to airpuff versus white-noise probes. Additionally, both probes elicited equal startle magnitudes, response probabilities, and levels of fear-potentiated startle. Such results support the use of low intensity airpuffs as efficacious and relatively non-aversive startle probes.

  3. Hyperreactivity to weak acoustic stimuli and prolonged acoustic startle latency in children with autism spectrum disorders

    PubMed Central

    2014-01-01

    Background People with autism spectrum disorders (ASD) are known to have enhanced auditory perception, however, acoustic startle response to weak stimuli has not been well documented in this population. The objectives of this study are to evaluate the basic profile of acoustic startle response, including peak startle latency and startle magnitude to weaker stimuli, in children with ASD and typical development (TD), and to evaluate their relationship to ASD characteristics. Methods We investigated acoustic startle response with weak and strong acoustic stimuli in 12 children with ASD and 28 children with TD, analyzing the relationship between startle measures and quantitative autistic traits assessed with the Social Responsiveness Scale (SRS). The electromyographic activity of the left orbicularis oculi muscle to acoustic stimuli of 65 to 115 dB sound pressure level (SPL), in increments of 5 dB, was measured to evaluate acoustic startle response. The average eyeblink magnitude for each acoustic stimuli intensity and the average peak startle latency of acoustic startle response were evaluated. Results The magnitude of the acoustic startle response to weak stimuli (85 dB or smaller) was greater in children with ASD. The peak startle latency was also prolonged in individuals with ASD. The average magnitude of the acoustic startle response for stimulus intensities greater than 85 dB was not significantly larger in the ASD group compared with the controls. Both greater startle magnitude in response to weak stimuli (particularly at 85 dB) and prolonged peak startle latency were significantly associated with total scores, as well as several subscales of the SRS in the whole sample. We also found a significant relationship between scores on the social cognition subscale of the SRS and the average magnitude of the acoustic startle response for stimulus intensities of 80 and 85 dB in the TD group. Conclusions Children with ASD exhibited larger startle magnitude to weak

  4. Winter is coming: Seasonality and the acoustic startle reflex.

    PubMed

    Armbruster, Diana; Brocke, Burkhard; Strobel, Alexander

    2017-02-01

    Circannual rhythms and seasonality have long been in the interest of research. In humans, seasonal changes in mood have been extensively investigated since a substantial part of the population experiences worsening of mood during winter. Questions remain regarding accompanying physiological phenomena. We report seasonal effects on the acoustic startle response in a cross-sectional (n=124) and a longitudinal sample (n=23). Startle magnitudes were larger in winter (sample 1: p=0.026; sample 2: p=0.010) compared to summer months. Although the findings need to be replicated they may have implications regarding the timing of startle experiments.

  5. Habituation and prepulse inhibition of acoustic startle in rodents.

    PubMed

    Valsamis, Bridget; Schmid, Susanne

    2011-09-01

    The acoustic startle response is a protective response, elicited by a sudden and intense acoustic stimulus. Facial and skeletal muscles are activated within a few milliseconds, leading to a whole body flinch in rodents(1). Although startle responses are reflexive responses that can be reliably elicited, they are not stereotypic. They can be modulated by emotions such as fear (fear potentiated startle) and joy (joy attenuated startle), by non-associative learning processes such as habituation and sensitization, and by other sensory stimuli through sensory gating processes (prepulse inhibition), turning startle responses into an excellent tool for assessing emotions, learning, and sensory gating, for review see( 2, 3). The primary pathway mediating startle responses is very short and well described, qualifying startle also as an excellent model for studying the underlying mechanisms for behavioural plasticity on a cellular/molecular level(3). We here describe a method for assessing short-term habituation, long-term habituation and prepulse inhibition of acoustic startle responses in rodents. Habituation describes the decrease of the startle response magnitude upon repeated presentation of the same stimulus. Habituation within a testing session is called short-term habituation (STH) and is reversible upon a period of several minutes without stimulation. Habituation between testing sessions is called long-term habituation (LTH)(4). Habituation is stimulus specific(5). Prepulse inhibition is the attenuation of a startle response by a preceding non-startling sensory stimulus(6). The interval between prepulse and startle stimulus can vary from 6 to up to 2000 ms. The prepulse can be any modality, however, acoustic prepulses are the most commonly used. Habituation is a form of non-associative learning. It can also be viewed as a form of sensory filtering, since it reduces the organisms' response to a non-threatening stimulus. Prepulse inhibition (PPI) was originally

  6. The Influence of Stuttering Severity on Acoustic Startle Responses

    ERIC Educational Resources Information Center

    Ellis, John B.; Finan, Donald S.; Ramig, Peter R.

    2008-01-01

    Purpose: This study examined the potential impact of stuttering severity, as measured by the Perceptions of Stuttering Inventory (Woolf, 1967) on acoustic startle responses. Method: Three groups, consisting of 10 nonstuttering adults, 9 mild stutterering adults, and 11 moderate/severe stutterering adults, were presented with identical 95-dB…

  7. First trial postural reactions to unexpected balance disturbances: a comparison with the acoustic startle reaction.

    PubMed

    Oude Nijhuis, Lars B; Allum, John H J; Valls-Solé, Josep; Overeem, Sebastiaan; Bloem, Bastiaan R

    2010-11-01

    Unexpected support-surface movements delivered during stance elicit "first trial" postural reactions, which are larger and cause greater instability compared with habituated responses. The nature of this first trial reaction remains unknown. We hypothesized that first trial postural reactions consist of a generalized startle reaction, with a similar muscle synergy as the acoustic startle response, combined with an automatic postural reaction. Therefore we compared acoustic startle responses to first trial postural reactions. Eight healthy subjects stood on a support surface that unexpectedly rotated backwards 10 times, followed by 10 startling acoustic stimuli, or vice versa. Outcome measures included full body kinematics and surface EMG from muscles involved in startle reactions or postural control. Postural perturbations and startling acoustic stimuli both elicited a clear first trial reaction, as reflected by larger kinematic and EMG responses. The ensuing habituation rate to repeated identical stimuli was comparable for neck and trunk muscles in both conditions. Onset latencies in neck muscles occurred significantly later for first trial perturbations compared with startle responses, but earlier in trunk muscles. Our results show that platform tilting initially induces reactions larger than needed to maintain equilibrium. For neck and trunk muscles, these first trial postural reactions resembled acoustic startle reflexes. First trial postural reactions may be triggered by interaction of afferent volleys formed by somatosensory and vestibular inputs. Acoustic startle reactions may also be partially triggered by vestibular inputs. Similar muscle activation driven by vestibular inputs may be the common element of first trial postural responses and acoustic startle reactions.

  8. Enhanced acoustic startle responding in rats with radiation-induced hippocampal granule cell hypoplasia

    SciTech Connect

    Mickley, G.A.; Ferguson, J.L.

    1989-01-01

    Irradiation of the neonatal rat hippocampus reduces the proliferation of granule cells in the dentate gyrus and results in locomotor hyperactivity, behavioral preservation, and deficits on some learned tasks. In order to address the role of changes in stimulus salience and behavioral inhibition in animals with this type of brain damage, irradiated and normal rats were compared in their startle reactions to an acoustic stimulus. Irradiated rats startled with a consistently higher amplitude than control and were more likely to exhibit startle responses. These animals with hippocampal damage also failed to habituate to the startle stimulus and, under certain circumstances, showed potentiated startle responses after many tone presentations.

  9. Excitatory and Inhibitory Effects of Serotonin on Sensorimotor Reactivity Measured with Acoustic Startle

    NASA Astrophysics Data System (ADS)

    Davis, Michael; Astrachan, David I.; Kass, Elizabeth

    1980-07-01

    Serotonin infused into the lateral ventricle in rats produced a dose-dependent depression of the acoustic startle reflex. When infused onto the spinal cord, serotonin produced a dose-dependent increase in startle. Thus the same neurotransmitter can modulate the same behavior in opposite ways, depending on which part of the central nervous system is involved.

  10. Anger and aggression problems in veterans are associated with an increased acoustic startle reflex.

    PubMed

    Heesink, Lieke; Kleber, Rolf; Häfner, Michael; van Bedaf, Laury; Eekhout, Iris; Geuze, Elbert

    2017-02-01

    Anger and aggression are frequent problems in deployed military personnel. A lowered threshold of perceiving and responding to threat can trigger impulsive aggression. This can be indicated by an exaggerated startle response. Fifty-two veterans with anger and aggression problems (Anger group) and 50 control veterans were tested using a startle experiment with 10 startle probes and 10 prepulse trials, presented in a random order and with a random interval between the trials. Predictors (demographics, Trait Anger, State Anger, Harm Avoidance and Anxious Arousal) for the startle response within the Anger group were tested. Increased EMG responses were found to the startle probes in the Anger Group compared to the Control group, but not to the prepulse trials. Furthermore, Harm Avoidance and State Anger predicted the increased startle reflex within the Anger group, whereas Trait Anger was negatively related to the startle reflex. These findings indicate that threat reactivity is increased in anger and aggression problems. These problems are not only caused by an anxious predisposition, the degree of anger also predicts the startle reflex.

  11. Baseline and Modulated Acoustic Startle Responses in Adolescent Girls with Posttraumatic Stress Disorder

    ERIC Educational Resources Information Center

    Lipschitz, Deborah S.; Mayes, Linda M.; Rasmusson, Ann M.; Anyan, Walter; Billingslea, Eileen; Gueorguieva, Ralitza; Southwick, Steven M.

    2005-01-01

    Objective: To assess baseline and modulated acoustic startle responses in adolescent girls with posttraumatic stress disorder (PTSD). Method: Twenty-eight adolescent girls with PTSD and 23 healthy control girls were recruited for participation in the study. Acoustic stimuli were bursts of white noise of 104 dB presented biaurally through…

  12. Amygdala central nucleus lesions attenuate acoustic startle stimulus-evoked heart rate changes in rats.

    PubMed

    Young, B J; Leaton, R N

    1996-04-01

    Amygdala central nucleus (CNA) lesions were used to test the hypothesis that stimulus-evoked heart rate changes can reflect the development of fear during acoustic startle testing. A 120-dB white noise startle stimulus produced freezing as well as phasic heart rate accelerations and decelerations, and an abrupt decrease in tonic heart rate, in sham-operated rats. These responses were all significantly reduced in CNA-lesioned rats. In contrast, an 87-dB stimulus elicited only significant phasic decelerations that were similarly attenuated by the CNA lesions. In a follow-up experiment, the CNA lesions also attenuated phasic cardiac decelerations evoked by a conditioned stimulus-like, 85-dB pure tone. The results support the contention (B. J. Young & R.N. Leaton, 1994) that heart rate changes can reflect fear conditioned during acoustic startle testing and, in addition, suggest that the amygdala mediates responses to nonsignal acoustic stimuli.

  13. Using a startling acoustic stimulus to investigate underlying mechanisms of bradykinesia in Parkinson's disease.

    PubMed

    Carlsen, Anthony N; Almeida, Quincy J; Franks, Ian M

    2013-02-01

    Delays in the initiation of a movement response and slowness during movement are among the hallmark motor symptoms in patients with Parkinson's disease (PD). These impairments may result from deficits in neural structures related to perception, response programming, response initiation, or a combination of all three. However, the relative impact of each process on movement control in PD is still unclear. The present study investigated which processes might be responsible for the observed slowness. Patients performed a simple reaction time (RT) task involving arm extension where the normal 82 dB acoustic "go" signal was unexpectedly replaced with a 124 dB startling acoustic stimulus (SAS) on selected trials. The SAS was used as a probe of motor preparatory state since it has been shown to act as a subcortically-mediated involuntarily trigger for actions that are sufficiently prepared and waiting to be initiated by normal cortical processes. It was expected that release of the voluntary response by startle would not occur in PD patients if bradykinetic symptoms were attributable primarily to motor programming deficits. In contrast, results clearly showed that when a SAS was presented, the prepared response was elicited at a significantly shorter latency. In addition, the amplitude and timing pattern of EMG output appeared to be improved compared to control, resulting in a faster, more normalized movement. These results suggest that in PD patients motor programming processes are relatively intact, while the dysfunctional basal ganglia likely assert an inhibitory effect on the thalamo-cortical connections responsible for the initiation of motor acts.

  14. Heritability and molecular genetic basis of acoustic startle eye blink and affectively modulated startle response: A genome-wide association study

    PubMed Central

    VAIDYANATHAN, UMA; MALONE, STEPHEN M.; MILLER, MICHAEL B.; McGUE, MATT; IACONO, WILLIAM G.

    2014-01-01

    Acoustic startle responses have been studied extensively in relation to individual differences and psychopathology. We examined three indices of the blink response in a picture-viewing paradigm—overall startle magnitude across all picture types, and aversive and pleasant modulation scores—in 3,323 twins and parents. Biometric models and molecular genetic analyses showed that half the variance in overall startle was due to additive genetic effects. No single nucleotide polymorphism was genome-wide significant, but GRIK3 did produce a significant effect when examined as part of a candidate gene set. In contrast, emotion modulation scores showed little evidence of heritability in either biometric or molecular genetic analyses. However, in a genome-wide scan, PARP14 did produce a significant effect for aversive modulation. We conclude that, although overall startle retains potential as an endophenotype, emotion-modulated startle does not. PMID:25387708

  15. Acoustic startle responses and temperament in individuals who stutter.

    PubMed

    Guitar, Barry

    2003-02-01

    Fourteen individuals who stutter and 14 individuals who do not stutter were presented with 10 bursts of white noise to assess the magnitude of their eyeblink responses as a measure of temperament. Both the magnitude of the eyeblink response to the initial noise burst and the mean of the 10 responses were significantly greater for the stuttering group. The Taylor-Johnson Temperament Analysis (R. M. Taylor & L P. Morrison, 1996) did not distinguish between the two groups, but informal follow-up statistics indicated that the Nervous subscale showed a significant group difference. Scores on this subscale were also significantly positively correlated with the magnitude of the startle response. A discriminant analysis demonstrated that although both the startle response and the nervous trait differentiated the two groups, the startle response measures were more powerful in making this differentiation.

  16. Stuttering and Sensory Gating: A Study of Acoustic Startle Prepulse Inhibition

    ERIC Educational Resources Information Center

    Alm, Per A.

    2006-01-01

    It was hypothesized that stuttering may be related to impaired sensory gating, leading to overflow of superfluous disturbing auditory feedback and breakdown of the speech sequence. This hypothesis was tested using the "acoustic startle prepulse inhibition" (PPI) paradigm. A group of 22 adults with developmental stuttering were compared…

  17. An acoustic startle-based method of assessing frequency discrimination in mice.

    PubMed

    Clause, Amanda; Nguyen, Tuan; Kandler, Karl

    2011-08-30

    The acoustic startle response (ASR) is a reflexive contraction of skeletal muscles in response to a loud, abrupt acoustic stimulus. ASR magnitude is reduced if the startle stimulus is preceded by a weaker acoustic or non-acoustic stimulus, a phenomenon known as prepulse inhibition (PPI). PPI has been used to test various aspects of sensory discrimination in both animals and humans. Here we show that PPI of the ASR is an advantageous method of assessing frequency discrimination. We describe the apparatus and its performance testing frequency discrimination in young CD1 mice. Compared to classical conditioning paradigms, PPI of the ASR is less time consuming, produces robust results, and can be used without training even in young animals. This approach can be used to investigate the neuronal mechanisms underlying frequency discrimination, its maturation during development, and its relationship to tonotopic organization.

  18. Dissociative identity disorder and prepulse inhibition of the acoustic startle reflex.

    PubMed

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

    2008-06-01

    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.

  19. 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

  20. Prepulse Inhibition of the Acoustic Startle Reflex in High Functioning Autism

    PubMed Central

    Gruendler, Theo O. J.; Vogeley, Kai; Klosterkötter, Joachim; Kuhn, Jens

    2014-01-01

    Background High functioning autism is an autism spectrum disorder that is characterized by deficits in social interaction and communication as well as repetitive and restrictive behavior while intelligence and general cognitive functioning are preserved. According to the weak central coherence account, individuals with autism tend to process information detail-focused at the expense of global form. This processing bias might be reflected by deficits in sensorimotor gating, a mechanism that prevents overstimulation during the transformation of sensory input into motor action. Prepulse inhibition is an operational measure of sensorimotor gating, which indicates an extensive attenuation of the startle reflex that occurs when a startling pulse is preceded by a weaker stimulus, the prepulse. Methods In the present study, prepulse inhibition of acoustic startle was compared between 17 adults with high functioning autism and 17 sex-, age-, and intelligence-matched controls by means of electromyography. Results Results indicate that participants with high functioning autism exhibited significantly higher startle amplitudes than the control group. However, groups did not differ with regard to PPI or habituation of startle. Discussion These findings challenge the results of two previous studies that reported prepulse inhibition deficits in high-functioning autism and suggest that sensorimotor gating is only impaired in certain subgroups with autism spectrum disorder. PMID:24643088

  1. Interaction between acoustic startle and habituated neck postural responses in seated subjects.

    PubMed

    Blouin, Jean-Sébastien; Siegmund, Gunter P; Timothy Inglis, J

    2007-04-01

    Postural and startle responses rapidly habituate with repeated exposures to the same stimulus, and the first exposure to a seated forward acceleration elicits a startle response in the neck muscles. Our goal was to examine how the acoustic startle response is integrated with the habituated neck postural response elicited by forward accelerations of seated subjects. In experiment 1, 14 subjects underwent 11 sequential forward accelerations followed by 5 additional sled accelerations combined with a startling tone (124-dB sound pressure level) initiated 18 ms after sled acceleration onset. During the acceleration-only trials, changes consistent with habituation occurred in the root-mean-square amplitude of the neck muscles and in the peak amplitude of five head and torso kinematic variables. The subsequent addition of the startling tone restored the amplitude of the neck muscles and four of the five kinematic variables but shortened onset of muscle activity by 9-12 ms. These shortened onset times were further explored in experiment 2, wherein 16 subjects underwent 11 acceleration-only trials followed by 15 combined acceleration-tone trials with interstimulus delays of 0, 13, 18, 23, and 28 ms. Onset times shortened further for the 0- and 13-ms delays but did not lengthen for the 23- and 28-ms delays. These temporal and spatial changes in EMG can be explained by a summation of the excitatory drive converging at or before the neck muscle motoneurons. The present observations suggest that habituation to repeated sled accelerations involves extinguishing the startle response and tuning the postural response to the whole body disturbance.

  2. A fast cholinergic modulation of the primary acoustic startle circuit in rats.

    PubMed

    Gómez-Nieto, Ricardo; Sinex, Donal G; Horta-Júnior, José de Anchieta C; Castellano, Orlando; Herrero-Turrión, Javier M; López, Dolores E

    2014-09-01

    Cochlear root neurons (CRNs) are the first brainstem neurons which initiate and participate in the full expression of the acoustic startle reflex. Although it has been suggested that a cholinergic pathway from the ventral nucleus of the trapezoid body (VNTB) conveys auditory prepulses to the CRNs, the neuronal origin of the VNTB-CRNs projection and the role it may play in the cochlear root nucleus remain uncertain. To determine the VNTB neuronal type which projects to CRNs, we performed tract-tracing experiments combined with mechanical lesions, and morphometric analyses. Our results indicate that a subpopulation of non-olivocochlear neurons projects directly and bilaterally to CRNs via the trapezoid body. We also performed a gene expression analysis of muscarinic and nicotinic receptors which indicates that CRNs contain a cholinergic receptor profile sufficient to mediate the modulation of CRN responses. Consequently, we investigated the effects of auditory prepulses on the neuronal activity of CRNs using extracellular recordings in vivo. Our results show that CRN responses are strongly inhibited by auditory prepulses. Unlike other neurons of the cochlear nucleus, the CRNs exhibited inhibition that depended on parameters of the auditory prepulse such as intensity and interstimulus interval, showing their strongest inhibition at short interstimulus intervals. In sum, our study supports the idea that CRNs are involved in the auditory prepulse inhibition of the acoustic startle reflex, and confirms the existence of multiple cholinergic pathways that modulate the primary acoustic startle circuit.

  3. Relationship between Toxoplasma gondii seropositivity and acoustic startle response in an inner-city population.

    PubMed

    Massa, Nick M; Duncan, Erica; Jovanovic, Tanja; Kerley, Kimberly; Weng, Lei; Gensler, Lauren; Lee, Samuel S; Norrholm, Seth; Powers, Abigail; Almli, Lynn M; Gillespie, Charles F; Ressler, Kerry; Pearce, Bradley D

    2017-03-01

    Toxoplasma gondii (TOXO) is a neuroinvasive protozoan parasite that induces the formation of persistent cysts in mammalian brains. It infects approximately 1.1million people in the United States annually. Latent TOXO infection is implicated in the etiology of psychiatric disorders, especially schizophrenia (SCZ), and has been correlated with modestly impaired cognition. The acoustic startle response (ASR) is a reflex seen in all mammals. It is mediated by a simple subcortical circuit, and provides an indicator of neural function. We previously reported the association of TOXO with slowed acoustic startle latency, an index of neural processing speed, in a sample of schizophrenia and healthy control subjects. The alterations in neurobiology with TOXO latent infection may not be specific to schizophrenia. Therefore we examined TOXO in relation to acoustic startle in an urban, predominately African American, population with mixed psychiatric diagnoses, and healthy controls. Physiological and diagnostic data along with blood samples were collected from 364 outpatients treated at an inner-city hospital. TOXO status was determined with an ELISA assay for TOXO-specific IgG. A discrete titer was calculated based on standard cut-points as an indicator of seropositivity, and the TOXO-specific IgG concentration served as serointensity. A series of linear regression models were used to assess the association of TOXO seropositivity and serointensity with ASR magnitude and latency in models adjusting for demographics and psychiatric diagnoses (PTSD, major depression, schizophrenia, psychosis, substance abuse). ASR magnitude was 11.5% higher in TOXO seropositive subjects compared to seronegative individuals (p=0.01). This effect was more pronounced in models with TOXO serointensity that adjusted for sociodemographic covariates (F=7.41, p=0.0068; F=10.05, p=0.0017), and remained significant when psychiatric diagnoses were stepped into the models. TOXO showed no association with

  4. Repeated low-dose exposures to sarin, soman, or VX affect acoustic startle in guinea pigs.

    PubMed

    Smith, C D; Lee, R B; Moran, A V; Sipos, M L

    2016-01-01

    Chemical warfare nerve agents (CWNAs) are known to cause behavioral abnormalities in cases of human exposures and in animal models. The behavioral consequences of single exposures to CWNAs that cause observable toxic signs are particularly well characterized in animals; however, less is known regarding repeated smaller exposures that may or may not cause observable toxic signs. In the current study, guinea pigs were exposed to fractions (0.1, 0.2, or 0.4) of a medial lethal dose (LD50) of sarin, soman, or VX for two weeks. On each exposure day, and for a post-exposure period, acoustic startle response (ASR) was measured in each animal. Although relatively few studies use guinea pigs to measure behavior, this species is ideal for CWNA-related experiments because their levels of carboxylesterases closely mimic those of humans, unlike rats or mice. Results showed that the 0.4 LD50 doses of soman and VX transiently increased peak startle amplitude by the second week of injections, with amplitude returning to baseline by the second week post-exposure. Sarin also increased peak startle amplitude independent of week. Latencies to peak startle and PPI were affected by agent exposure but not consistently among the three agents. Most of the changes in startle responses returned to baseline following the cessation of exposures. These data suggest that doses of CWNAs not known to produce observable toxic signs in guinea pigs can affect behavior in the ASR paradigm. Further, these deficits are transient and usually return to baseline shortly after the end of a two-week exposure period.

  5. A Hardware-and-Software System for Experimental Studies of the Acoustic Startle Response in Laboratory Rodents.

    PubMed

    Pevtsov, E F; Storozheva, Z I; Proshin, A T; Pevtsova, E I

    2016-02-01

    We developed and tested a novel hardware-and-software system for recording the amplitude of the acoustic startle response in rodents. In our experiments, the baseline indexes of acoustic startle response in laboratory rats and pre-stimulation inhibition under the standard delivery of acoustic stimulation were similar to those evaluated by other investigators on foreign devices. The proposed system is relatively cheap and provides the possibility of performing experiments on freely moving specimens. It should be emphasized that the results of studies can be processed with free-access software.

  6. Startle modulation before, during and after exposure to emotional stimuli.

    PubMed

    Dichter, Gabriel S; Tomarken, Andrew J; Baucom, Brian R

    2002-02-01

    Although affective modulation of the startle reflex is a highly replicable effect, the majority of studies have administered startle probes during exposure to affective stimuli. To examine more comprehensively the temporal course of startle potentiation, we assessed blink modulation before, during and immediately after exposure to positive, negative and neutral pictures. During each trial, cues about the affective content of pictures were presented, after which acoustic startle probes were delivered either before picture onset, during picture onset or immediately after picture offset. As expected, we observed a linear relation between picture valence and startle amplitude during picture viewing. Surprisingly, startle amplitude was larger while anticipating pleasant and unpleasant pictures relative to neutral pictures. No significant effects were observed during the offset phase. These results indicate that startle modulation is conditional upon temporal factors linked to stimulus onset and offset.

  7. Interactions Between Corticotropin-Releasing Factor and the Serotonin 1A Receptor System on Acoustic Startle Amplitude and Prepulse Inhibition of the Startle Response in Two Rat Strains

    PubMed Central

    Conti, Lisa H.

    2011-01-01

    Both the neuropeptide, corticotropin-releasing factor (CRF) and the serotonin 1A (5-HT1A) receptor systems have been implicated in anxiety disorders and there is evidence that the two systems interact with each other to affect behavior. Both systems have individually been shown to affect prepulse inhibition (PPI) of the acoustic startle response. PPI is a form of sensorimotor gating that is reduced in patients with anxiety disorders including post-traumatic stress and panic disorder. Here, we examined whether the two systems interact or counteract each other to affect acoustic startle amplitude, PPI and habituation of the startle response. In experiment 1, Brown Norway (BN) and Wistar-Kyoto (WKY) rats were administered ether an intraperitoneal (IP) injection of saline or the 5-HT1A receptor agonist, 8-OH-DPAT 10 min prior to receiving an intracerebroventricular (ICV) infusion of either saline or CRF (0.3 µg). In a second experiment, rats were administered either an IP injection of saline or the 5-HT1A receptor antagonist, WAY 100,635 10 min prior to receiving an ICV infusion of saline or CRF. Thirty min after the ICV infusion, the startle response and PPI were assessed. As we have previously shown, the dose of CRF used in these experiments reduced PPI in BN rats and had no effect on PPI in WKY rats. Administration of 8-OH-DPAT alone had no effect on PPI in either rat strain when the data from the two strains were examined separately. Administration of 8-OHDPAT added to the effect of CRF in BN rats, and the combination of 8-OH-DPAT and CRF significantly reduced PPI in WKY rats. CRF alone had no effect on baseline startle amplitude in either rat strain, but CRF enhanced the 8-OH-DPAT-induced increase in startle in both strains. Administration of WAY 100,635 did not affect the CRF-induced change in PPI and there were no interactions between CRF and WAY 100,635 on baseline startle. The results suggest that activation of the 5-HT1A receptor can potentiate the effect of

  8. Long-Lasting Suppression of Acoustic Startle Response after Mild Traumatic Brain Injury

    PubMed Central

    Sinha, Swamini; Avcu, Pelin; Roland, Jessica J.; Nadpara, Neil; Pfister, Bryan; Long, Mathew; Santhakumar, Vijayalakshmi; Servatius, Richard J.

    2015-01-01

    Abstract Acoustic startle response (ASR) is a defensive reflex that is largely ignored unless greatly exaggerated. ASR is suppressed after moderate and severe traumatic brain injury (TBI), but the effect of mild TBI (mTBI) on ASR has not been investigated. Because the neural circuitry for ASR resides in the pons in all mammals, ASR may be a good measure of brainstem function after mTBI. The present study assessed ASR in Sprague-Dawley rats after mTBI using lateral fluid percussion and compared these effects to those on spatial working memory. mTBI caused a profound, long-lasting suppression of ASR. Both probability of emitting a startle and startle amplitude were diminished. ASR suppression was observed as soon as 1 day after injury and remained suppressed for the duration of the study (21 days after injury). No indication of recovery was observed. mTBI also impaired spatial working memory. In contrast to the suppression of ASR, working memory impairment was transient; memory was impaired 1 and 7 days after injury, but recovered by 21 days. The long-lasting suppression of ASR suggests long-term dysfunction of brainstem neural circuits at a time when forebrain neural circuits responsible for spatial working memory have recovered. These results have important implications for return-to-activity decisions because recovery of cognitive impairments plays an important role in these decisions. PMID:25412226

  9. Long-lasting suppression of acoustic startle response after mild traumatic brain injury.

    PubMed

    Pang, Kevin C H; Sinha, Swamini; Avcu, Pelin; Roland, Jessica J; Nadpara, Neil; Pfister, Bryan; Long, Mathew; Santhakumar, Vijayalakshmi; Servatius, Richard J

    2015-06-01

    Acoustic startle response (ASR) is a defensive reflex that is largely ignored unless greatly exaggerated. ASR is suppressed after moderate and severe traumatic brain injury (TBI), but the effect of mild TBI (mTBI) on ASR has not been investigated. Because the neural circuitry for ASR resides in the pons in all mammals, ASR may be a good measure of brainstem function after mTBI. The present study assessed ASR in Sprague-Dawley rats after mTBI using lateral fluid percussion and compared these effects to those on spatial working memory. mTBI caused a profound, long-lasting suppression of ASR. Both probability of emitting a startle and startle amplitude were diminished. ASR suppression was observed as soon as 1 day after injury and remained suppressed for the duration of the study (21 days after injury). No indication of recovery was observed. mTBI also impaired spatial working memory. In contrast to the suppression of ASR, working memory impairment was transient; memory was impaired 1 and 7 days after injury, but recovered by 21 days. The long-lasting suppression of ASR suggests long-term dysfunction of brainstem neural circuits at a time when forebrain neural circuits responsible for spatial working memory have recovered. These results have important implications for return-to-activity decisions because recovery of cognitive impairments plays an important role in these decisions.

  10. Stuttering and sensory gating: a study of acoustic startle prepulse inhibition.

    PubMed

    Alm, Per A

    2006-06-01

    It was hypothesized that stuttering may be related to impaired sensory gating, leading to overflow of superfluous disturbing auditory feedback and breakdown of the speech sequence. This hypothesis was tested using the acoustic startle prepulse inhibition (PPI) paradigm. A group of 22 adults with developmental stuttering were compared with controls regarding the degree of PPI. No significant differences were found between the stuttering adults and the control group; the groups showed similar means and distribution. Likewise, no relation between the degree of PPI and the effect of altered auditory feedback on stuttering was found. In summary, the results of the study indicate that there is no relation between stuttering and PPI.

  11. Responses to startling acoustic stimuli indicate that movement-related activation is constant prior to action: a replication with an alternate interpretation

    PubMed Central

    Maslovat, Dana; Franks, Ian M; Leguerrier, Alexandra; Carlsen, Anthony N

    2015-01-01

    A recent study by Marinovic et al. (J. Neurophysiol., 2013, 109: 996–1008) used a loud acoustic stimulus to probe motor preparation in a simple reaction time (RT) task. Based on decreasing RT latency and increases in motor output measures as the probe stimulus approached the “go” stimulus, the authors concluded that response-related activation increased abruptly 65 ms prior to the imperative stimulus, a result in contrast to previous literature. However, this study did not measure reflexive startle activity in the sternocleidomastoid (SCM) muscle, which has been used to delineate between response triggering by a loud acoustic stimuli and effects of stimulus intensity and/or intersensory facilitation. Due to this methodological limitation, it was unclear if the data accurately represented movement-related activation changes. In order to provide a measure as to whether response triggering occurred on each trial, the current experiment replicated the study by Marinovic et al., with the collection of muscle activation in the SCM. While the replication analyses involving all trials confirmed similar results to those reported by Marinovic et al., when data were limited to those in which startle-related SCM activation occurred, the results indicated that movement-related activation is constant in the 65 ms prior to action initiation. The difference between analyses suggests that when SCM activation is not considered, results may be confounded by trials in which the probe stimulus does not trigger the prepared response. Furthermore, these results provide additional confirmation that reflexive startle activation in the SCM is a robust indicator of response triggering by a loud acoustic stimulus. PMID:25663524

  12. Acoustic startle response in rats predicts inter-individual variation in fear extinction.

    PubMed

    Russo, Amanda S; Parsons, Ryan G

    2017-03-01

    Although a large portion of the population is exposed to a traumatic event at some point, only a small percentage of the population develops post-traumatic stress disorder (PTSD), suggesting the presence of predisposing factors. Abnormal acoustic startle response (ASR) has been shown to be associated with PTSD, implicating it as a potential predictor of the development of PTSD-like behavior. Since poor extinction and retention of extinction learning are characteristic of PTSD patients, it is of interest to determine if abnormal ASR is predictive of development of such deficits. To determine whether baseline ASR has utility in predicting the development of PTSD-like behavior, the relationship between baseline ASR and freezing behavior following Pavlovian fear conditioning was examined in a group of adult, male Sprague-Dawley rats. Baseline acoustic startle response (ASR) was assessed preceding exposure to a Pavlovian fear conditioning paradigm where freezing behavior was measured during fear conditioning, extinction training, and extinction testing. Although there was no relationship between baseline ASR and fear memory following conditioning, rats with low baseline ASR had significantly lower magnitude of retention of the extinction memory than rats with high baseline ASR. The results suggest that baseline ASR has value as a predictive index of the development of a PTSD-like phenotype.

  13. Induction of enhanced acoustic startle response by noise exposure: dependence on exposure conditions and testing parameters and possible relevance to hyperacusis.

    PubMed

    Salloum, Rony H; Yurosko, Christopher; Santiago, Lia; Sandridge, Sharon A; Kaltenbach, James A

    2014-01-01

    There has been a recent surge of interest in the development of animal models of hyperacusis, a condition in which tolerance to sounds of moderate and high intensities is diminished. The reasons for this decreased tolerance are likely multifactorial, but some major factors that contribute to hyperacusis are increased loudness perception and heightened sensitivity and/or responsiveness to sound. Increased sound sensitivity is a symptom that sometimes develops in human subjects after acoustic insult and has recently been demonstrated in animals as evidenced by enhancement of the acoustic startle reflex following acoustic over-exposure. However, different laboratories have obtained conflicting results in this regard, with some studies reporting enhanced startle, others reporting weakened startle, and still others reporting little, if any, change in the amplitude of the acoustic startle reflex following noise exposure. In an effort to gain insight into these discrepancies, we conducted measures of acoustic startle responses (ASR) in animals exposed to different levels of sound, and repeated such measures on consecutive days using a range of different startle stimuli. Since many studies combine measures of acoustic startle with measures of gap detection, we also tested ASR in two different acoustic contexts, one in which the startle amplitudes were tested in isolation, the other in which startle amplitudes were measured in the context of the gap detection test. The results reveal that the emergence of chronic hyperacusis-like enhancements of startle following noise exposure is highly reproducible but is dependent on the post-exposure thresholds, the time when the measures are performed and the context in which the ASR measures are obtained. These findings could explain many of the discrepancies that exist across studies and suggest guidelines for inducing in animals enhancements of the startle reflex that may be related to hyperacusis.

  14. Noise exposure during early development influences the acoustic startle reflex in adult rats.

    PubMed

    Rybalko, Natalia; Bureš, Zbyněk; Burianová, Jana; Popelář, Jiří; Grécová, Jolana; Syka, Josef

    2011-03-28

    Noise exposure during the critical period of postnatal development in rats results in anomalous processing of acoustic stimuli in the adult auditory system. In the present study, the behavioral consequences of an acute acoustic trauma in the critical period are assessed in adult rats using the acoustic startle reflex (ASR) and prepulse inhibition (PPI) of ASR. Rat pups (strain Long-Evans) were exposed to broad-band noise of 125 dB SPL for 8 min on postnatal day 14; at the age of 3-5 months, ASR and PPI of ASR were examined and compared with those obtained in age-matched controls. In addition, hearing thresholds were measured in all animals by means of auditory brainstem responses. The results show that although the hearing thresholds in both groups of animals were not different, a reduced strength of the startle reflex was observed in exposed rats compared with controls. The efficacy of PPI in exposed and control rats was also markedly different. In contrast to control rats, in which an increase in prepulse intensity was accompanied by a consistent increase in the efficacy of PPI, the PPI function in the exposed animals was characterized by a steep increase in inhibitory efficacy at low prepulse intensities of 20-30 dB SPL. A further increase of prepulse intensity up to 60-70 dB SPL caused only a small and insignificant change of PPI. Our findings demonstrate that brief noise exposure in rat pups results in altered behavioral responses to sounds in adulthood, indicating anomalies in intensity coding and loudness perception.

  15. Lesions of the paraventricular thalamic nucleus attenuates prepulse inhibition of the acoustic startle reflex.

    PubMed

    Öz, Pınar; Kaya Yertutanol, F Duygu; Gözler, Tayfun; Özçetin, Ayşe; Uzbay, I Tayfun

    2017-03-06

    The paraventricular thalamic nucleus (PVT) is a midline nucleus with strong connections to cortical and subcortical brain regions such as the prefrontal cortex, amygdala, nucleus accumbens and hippocampus and receives strong projections from brain stem nuclei. Prepulse inhibition (PPI) is mediated and modulated by complex cortical and subcortical networks that are yet to be fully identified in detail. Here, we suggest that the PVT may be an important brain region for the modulation of PPI. In our study, the paraventricular thalamic nuclei of rats were electrolytically lesioned. Two weeks after the surgery, the PPI responses of the animals were monitored and recorded using measurements of acoustic startle reflex. Our results show that disruption of the PVT dramatically attenuated PPI at prepulse intensities of 74, 78 and 86dB compared to that in the sham lesion group. Thus, we suggest that the PVT may be an important part of the PPI network in the rat brain.

  16. Modality of fear cues affects acoustic startle potentiation but not heart-rate response in patients with dental phobia

    PubMed Central

    Wannemüller, André; Sartory, Gudrun; Elsesser, Karin; Lohrmann, Thomas; Jöhren, Hans P.

    2015-01-01

    The acoustic startle response (SR) has consistently been shown to be enhanced by fear-arousing cross-modal background stimuli in phobics. Intra-modal fear-potentiation of acoustic SR was rarely investigated and generated inconsistent results. The present study compared the acoustic SR to phobia-related sounds with that to phobia-related pictures in 104 dental phobic patients and 22 controls. Acoustic background stimuli were dental treatment noises and birdsong and visual stimuli were dental treatment and neutral control pictures. Background stimuli were presented for 4 s, randomly followed by the administration of the startle stimulus. In addition to SR, heart-rate (HR) was recorded throughout the trials. Irrespective of their content, background pictures elicited greater SR than noises in both groups with a trend for phobic participants to show startle potentiation to phobia-related pictures but not noises. Unlike controls, phobics showed HR acceleration to both dental pictures and noises. HR acceleration of the phobia group was significantly positively correlated with SR in the noise condition only. The acoustic SR to phobia-related noises is likely to be inhibited by prolonged sensorimotor gating. PMID:25774142

  17. On Again, Off Again Effects of Gonadectomy on the Acoustic Startle Reflex in Adult Male Rats

    PubMed Central

    Turvin, J.C.; Messer, W.S.

    2007-01-01

    Numerous studies have shown sex and/or estrous cycle differences in the acoustic startle reflex (ASR) and its prepulse inhibition (PPI) in humans and animals. However, few have examined the effects of hormone manipulations on these behaviors. This study paired gonadectomy (GDX) in adult male rats with testing for ASR and PPI at 2, 4, 9, 16, 23, 30 and 37 days after surgery. Initial studies of control, GDX and GDX rats given testosterone propionate revealed no group differences in PPI, but did reveal phasic facilitation of the ASR in GDX rats that was greatest on the first and final testing sessions and that was attenuated by testosterone. A second study addressing roles for estrogen and androgen signaling tested new control and GDX rats along with GDX rats given estradiol or the non-aromatizable androgen, 5-alpha-dihydrotestosterone and revealed no group differences in PPI, and increases in ASR in GDX rats that were largest during the first and final testing sessions and that were attenuated by both hormone replacements. However, while responses in GDX rats given testosterone were similar to those of controls, ASR in estradiol- and to a lesser extent in dihydrotestosterone-treated GDX rats were typically lower than in controls. This may suggest that hormone modulation of the ASR requires synergistic estrogen and androgen actions. In the male brain where this can be achieved by local steroid metabolism, the enzymes responsible, e.g., aromatase, could help identify loci in the startle circuitry that may be especially relevant for the hormone modulation observed. PMID:17169383

  18. Neurochemistry of the afferents to the rat cochlear root nucleus: Possible synaptic modulation of the acoustic startle

    PubMed Central

    Gómez-Nieto, R; Horta-Junior, JAC; Castellano, O; Herrero-Turrión, MJ; Rubio, ME; López, DE

    2008-01-01

    Afferents to the primary startle circuit are essential for the elicitation and modulation of the acoustic startle reflex (ASR). In the rat, cochlear root neurons (CRNs) comprise the first component of the acoustic startle circuit and play a crucial role in mediating the ASR. Nevertheless, the neurochemical pattern of their afferents remains unclear. To determine the distribution of excitatory and inhibitory inputs, we used confocal microscopy to analyze the immunostaining for vesicular glutamate and GABA transporter proteins (VGLUT1 and VGAT) on retrogradely labeled CRNs. We also used reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry to detect and localize specific neurotransmitter receptor subunits in the cochlear root. Our results show differential distributions of VGLUT1- and VGAT-immunoreactive endings around cell bodies and dendrites. The RT-PCR data showed a positive band for several ionotropic glutamate receptor subunits, M1- M5 muscarinic receptor subtypes, the glycine receptor α1 subunit (GlyRα1), GABAA, GABAB, and subunits of α2 and β-noradrenergic receptors. By immunohistochemistry, we confirmed that CRN cell bodies exhibit positive immunoreaction for the GluR3 and NR1 glutamate receptor subunits. Cell bodies and dendrites were also positive for M2 and M4, and GlyRα1. Other subunits, such as GluR1 and GluR4 of the AMPA glutamate receptors, were observed in glial cells neighboring unlabeled CRN cell bodies. We further confirmed the existence of noradrenergic afferents onto CRNs from the locus coeruleus by combining tyrosine hydroxylase immunohistochemistry and tract-tracing experiments. Our results provide valuable information toward understanding how CRNs might integrate excitatory and inhibitory inputs, and hence how they could elicit and modulate the acoustic startle reflex. PMID:18384963

  19. Tissue plasminogen activator in the bed nucleus of stria terminalis regulates acoustic startle.

    PubMed

    Matys, T; Pawlak, R; Strickland, S

    2005-01-01

    The bed nucleus of stria terminalis is a basal forebrain region involved in regulation of hormonal and behavioral responses to stress. In this report we demonstrate that bed nucleus of stria terminalis has a high and localized expression of tissue plasminogen activator, a serine protease with neuromodulatory properties and implicated in neuronal plasticity. Tissue plasminogen activator activity in the bed nucleus of stria terminalis is transiently increased in response to acute restraint stress or i.c.v. administration of a major stress mediator, corticotropin-releasing factor. We show that tissue plasminogen activator is important in bed nucleus of stria terminalis function using two criteria: 1, Neuronal activation in this region as measured by c-fos induction is reduced in tissue plasminogen activator-deficient mice; and 2, a bed nucleus of stria terminalis-dependent behavior, potentiation of acoustic startle by corticotropin-releasing factor, is attenuated in tissue plasminogen activator-deficient mice. These studies identify a novel site of tissue plasminogen activator expression in the mouse brain and demonstrate a functional role for this protease in the bed nucleus of stria terminalis.

  20. Changes in acoustic startle reflex in rats induced by playback of 22-kHz calls.

    PubMed

    Inagaki, Hideaki; Ushida, Takahiro

    2017-02-01

    In aversive or dangerous situations, adult rats emit long characteristic ultrasonic calls, often termed "22-kHz calls," which have been suggested to play a role of alarm calls. Although the playback experiment is one of the most effective ways to investigate the alarming properties of 22-kHz calls, clear behavioral evidence showing the anxiogenic effects of these playback stimuli has not been directly obtained to date. In this study, we investigated whether playback of 22-kHz calls or synthesized sine tones could change the acoustic startle reflex (ASR), enhancement of which is widely considered to be a reliable index of anxiety-related negative affective states in rats. Playback of 22-kHz calls significantly enhanced the ASR in rats. Enhancement effects caused by playback of 22-kHz calls from young rats were relatively weak compared to those after calls from adult rats. Playback of synthesized 25-kHz sine tones enhanced ASR in subjects, but not synthesized 60-kHz tones. Further, shortening the individual call duration of synthesized 25-kHz sine tones also enhanced the ASR. Accordingly, it is suggested that 22-kHz calls induce anxiety by socially communicated alarming signals in rats. The results also demonstrated that call frequency, i.e., of 22kHz, appears important for ultrasonic alarm-signal communication in rats.

  1. The Acoustic Startle Response and Disruption of Aiming. 2. Modulation by Forewarning and Preliminary Stimuli

    DTIC Science & Technology

    1989-11-01

    effective startle stimulus. Similarly, the startle reflex is attenuated by brief, irrele- ’ Requests for reprints should be addressed to James R. vant ...extreme responses, and for nine of these on perceptual-motor behavior, though Hoff - subjects the responses were nmore common on man and Fleshier (1963

  2. Effects of inescapable stress and treatment with pyridostigmine bromide on plasma butyrylcholinesterase and the acoustic startle response in rats.

    PubMed

    Servatius, R J; Ottenweller, J E; Guo, W; Beldowicz, D; Zhu, G; Natelson, B H

    2000-05-01

    Pyridostigmine bromide (PB) is a reversible, peripherally active inhibitor of acetylcholinesterase (AChE) activity, and is recommended by the military as a pretreatment against potential nerve gas exposure. Recent evidence suggests that exposure to inescapable stressors allows PB to cross the blood-brain barrier, and thereby affect central AChE activity in mice. Here, we evaluated the functional impact of a stress/PB treatment interaction on acoustic startle responding and plasma butyrylcholinesterase (BuChE) activity in male Sprague-Dawley rats. To model the treatment protocol used by the military, PB was delivered in the drinking water of rats for 7 consecutive days. The morning after the start of PB treatment, and for the next 6 days, half the rats were exposed to 1 h of supine restraint stress. We therefore employed a 2 x 2 (stress x PB treatment) between-groups design. Exposure to supine stress alone induced a persistent decrease in plasma BuChE activity. Further decreases in BuChE activity were not observed in rats exposed to supine restraint and PB treatment. Exposure to stress also induced an exaggerated startle response, evident on the last day of stress and 24 h after stressor cessation. Treatment with PB alone produced an exaggerated startle response over the same time period, albeit to a lesser degree. Although treatment with PB concurrent with stress did not produce further changes in either BuChE activity or acoustic startle responding, stress-induced alterations in drinking behavior (and thereby the dose of PB ingested) may have affected these results. Persistent stress-induced reductions in BuChE activity may increase the risk of adverse reactions to cholinomimetics.

  3. Reduced acoustic startle response and peripheral hearing loss in the 5xFAD mouse model of Alzheimer's disease.

    PubMed

    O'Leary, Timothy P; Shin, Sooyoun; Fertan, Emre; Dingle, Rachel N; Almuklass, Awad; Gunn, Rhian K; Yu, Zhiping; Wang, Jian; Brown, Richard E

    2017-01-29

    Hearing dysfunction has been associated with Alzheimer's disease in humans, but there is little data on the auditory function of mouse models of Alzheimer's disease. Furthermore, characterization of hearing ability in mouse models is needed to ensure that tests of cognition that use auditory stimuli are not confounded by hearing dysfunction. Therefore we assessed acoustic startle response and pre-pulse inhibition in the double transgenic 5xFAD mouse model of Alzheimer's disease from 3-4 to 16 months of age. The 5xFAD mice demonstrated an age-related decline in acoustic startle as early as 3-4 months of age. We subsequently tested Auditory Brainstem Response (ABR) thresholds at 4 and 13-14 months of age using tone-bursts at frequencies of 2- 32 kHz. The 5xFAD mice showed increased ABR thresholds for tone-bursts between 8 and 32Khz at 13-14 months of age. Finally, cochleae were extracted and basilar membranes were dissected to count hair cell loss across the cochlea. The 5xFAD mice showed significantly greater loss of both inner and outer hair cells at the apical and basal ends of the basilar membrane than wildtype mice at 15-16 months of age. These results indicate that the 5xFAD mouse model of Alzheimer's disease shows age-related decreases in acoustic startle responses, which are at least partially due to age-related peripheral hearing loss. Therefore, we caution against the use of cognitive tests that rely on audition in 5xFAD mice over 3-4 months of age, without first confirming that performance is not confounded by hearing dysfunction.

  4. Stimulus quality affects expression of the acoustic startle response and prepulse inhibition in mice.

    PubMed

    Stoddart, C W; Noonan, J; Martin-Iverson, M T

    2008-06-01

    The relationship between stimulus intensity and startle response magnitude (SIRM) can assess the startle reflex and prepulse inhibition (PPI) with advantages over more commonly used methods. The current study used the SIRM relationships in mice to determine differences between white noise and pure tone (5 kHz) stimuli. Similarly to rats, the SIRM relationship showed a sigmoid pattern. The SIRM-derived reflex capacity (RMAX) and response efficacy (slope) of the white noise and pure tone stimuli in the absence of prepulses were equivalent. However, the pure tone startle response threshold (DMIN) was increased whereas the stimulus potency (1/ES50) was decreased when compared to white noise. Prepulses of both stimulus types inhibited RMAX and increased DMIN, but the white noise prepulses were more effective. Both stimulus intensity gating and motor capacity gating processes are shown to occur, dependent on prepulse intensity and stimulus onset asynchrony. Prepulse intensities greater than 10 dB below the startle threshold appear to produce PPI via stimulus intensity gating, whereas a motor capacity gating component appears at prepulse intensities near to the startle threshold.

  5. Acoustic startle and prepulse inhibition predict smoking lapse in posttraumatic stress disorder.

    PubMed

    Vrana, Scott R; Calhoun, Patrick S; Dennis, Michelle F; Kirby, Angela C; Beckham, Jean C

    2015-10-01

    Most smokers who attempt to quit lapse within the first week and are ultimately unsuccessful in their quit attempt. Nicotine withdrawal exacerbates cognitive and attentional problems and may be one factor in smoking relapse. The startle reflex response and prepulse inhibition (PPI) of the response are sensitive to arousal and early attentional dysregulation. The current study examined whether startle response and PPI are related to early smoking lapse, and if this differs in people with and without posttraumatic stress disorder (PTSD). Participants with (N = 34) and without (N = 57) PTSD completed a startle reflex and PPI assessment during (1) ad lib smoking (2) on the first day of abstinence during a quit attempt. Most (88%) participants lapsed within the first week of the quit attempt. PTSD status predicted shorter time to lapse. Larger startle magnitude and greater PPI predicted a longer duration before smoking lapse. When diagnostic groups were examined separately, greater PPI predicted a longer successful quit attempt only in participants with a PTSD diagnosis. The startle reflex response and PPI may provide an objective, neurophysiological evaluation of regulation of arousal and early attentional processes by nicotine, which are important factors in smoking cessation success.

  6. Probing Prejudice with Startle Eyeblink Modification: A Marker of Attention, Emotion, or Both?

    PubMed Central

    Vanman, Eric J.; Ryan, John P.; Pedersen, William C.; Ito, Tiffany A.

    2015-01-01

    In social neuroscience research, startle eyeblink modification can serve as a marker of emotion, but it is less clear whether it can also serve as a marker of prejudice. In Experiment 1, 30 White students viewed photographs of White and Black targets while the startle eyeblink reflex and facial EMG from the brow and cheek regions were recorded. Prejudice was related to facial EMG activity, but not to startle modification, which instead appeared to index attention to race. To test further whether racial categorizations are associated with differential attention, a dual-task paradigm was used in Experiment 2. Fifty-four White and fifty-five Black participants responded more slowly to a tone presented when viewing a racial outgroup member or a negative stimulus, indicating that both draw more attention than ingroup members or positive stimuli. We conclude that startle modification is useful to index differential attention to groups when intergroup threat is low. PMID:26023325

  7. Investigation of Stimulus-Response Compatibility Using a Startling Acoustic Stimulus

    ERIC Educational Resources Information Center

    Maslovat, Dana; Carlsen, Anthony N.; Franks, Ian M.

    2012-01-01

    We investigated the processes underlying stimulus-response compatibility by using a lateralized auditory stimulus in a simple and choice reaction time (RT) paradigm. Participants were asked to make either a left or right key lift in response to either a control (80dB) or startling (124dB) stimulus presented to either the left ear, right ear, or…

  8. Effects of cold pressor stress on the human startle response.

    PubMed

    Deuter, Christian E; Kuehl, Linn K; Blumenthal, Terry D; Schulz, André; Oitzl, Melly S; Schachinger, Hartmut

    2012-01-01

    Both emotion and attention are known to influence the startle response. Stress influences emotion and attention, but the impact of stress on the human startle response remains unclear. We used an established physiological stressor, the Cold Pressor Test (CPT), to induce stress in a non-clinical human sample (24 student participants) in a within-subjects design. Autonomic (heart rate and skin conductance) and somatic (eye blink) responses to acoustic startle probes were measured during a pre-stress baseline, during a three minutes stress intervention, and during the subsequent recovery period. Startle skin conductance and heart rate responses were facilitated during stress. Compared to baseline, startle eye blink responses were not affected during the intervention but were diminished afterwards. These data describe a new and unique startle response pattern during stress: facilitation of autonomic stress responses but no such facilitation of somatic startle eye blink responses. The absence of an effect of stress on startle eye blink responsiveness may illustrate the importance of guaranteeing uninterrupted visual input during periods of stress.

  9. Effects of Cold Pressor Stress on the Human Startle Response

    PubMed Central

    Deuter, Christian E.; Kuehl, Linn K.; Blumenthal, Terry D.; Schulz, André; Oitzl, Melly S.; Schachinger, Hartmut

    2012-01-01

    Both emotion and attention are known to influence the startle response. Stress influences emotion and attention, but the impact of stress on the human startle response remains unclear. We used an established physiological stressor, the Cold Pressor Test (CPT), to induce stress in a non-clinical human sample (24 student participants) in a within-subjects design. Autonomic (heart rate and skin conductance) and somatic (eye blink) responses to acoustic startle probes were measured during a pre-stress baseline, during a three minutes stress intervention, and during the subsequent recovery period. Startle skin conductance and heart rate responses were facilitated during stress. Compared to baseline, startle eye blink responses were not affected during the intervention but were diminished afterwards. These data describe a new and unique startle response pattern during stress: facilitation of autonomic stress responses but no such facilitation of somatic startle eye blink responses. The absence of an effect of stress on startle eye blink responsiveness may illustrate the importance of guaranteeing uninterrupted visual input during periods of stress. PMID:23166784

  10. Postauricular reflexes elicited by soft acoustic clicks and loud noise probes: Reliability, prepulse facilitation, and sensitivity to picture contents.

    PubMed

    Aaron, Rachel V; Benning, Stephen D

    2016-12-01

    The startle blink reflex is facilitated during early picture viewing, then inhibited by attention during pleasant and aversive pictures compared to neutral pictures, and finally potentiated during aversive pictures specifically. However, it is unclear whether the postauricular reflex, which is elicited by the same loud acoustic probe as the startle blink reflex but enhanced by appetitive instead of defensive emotion, has the same pattern and time course of emotional modulation. We examined this issue in a sample of 90 undergraduates using serially presented soft acoustic clicks that elicited postauricular (but not startle blink) reflexes in addition to standard startle probes. Postauricular reflexes elicited by both clicks and probes correlated during food and nurturant contents, during which they were potentiated compared to neutral pictures, suggesting clicks effectively elicit emotionally modulated postauricular reflexes. The postauricular reflex was initially facilitated during the first 500 ms of picture processing but was larger during pleasant than neutral pictures throughout picture processing, with larger effect sizes during the latter half of picture processing. Across reflexes and eliciting stimuli, measures of emotional modulation had higher coefficient alphas than magnitudes during specific picture contents within each valence, indicating that only emotional modulation measures assess higher-order appetitive or defensive processing.

  11. Relationship of the Acoustic Startle Response and Its Modulation to Emotional and Behavioral Problems in Typical Development Children and Those with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Takahashi, Hidetoshi; Komatsu, Sahoko; Nakahachi, Takayuki; Ogino, Kazuo; Kamio, Yoko

    2016-01-01

    Auditory hyper-reactivity is a common sensory-perceptual abnormality in autism spectrum disorders (ASD), which interrupts behavioral adaptation. We investigated acoustic startle response (ASR) modulations in 17 children with ASD and 27 with typical development (TD). Compared to TD, children with ASD had larger ASR magnitude to weak stimuli and…

  12. Effects of VX on Acoustic Startle Response and Acquisition of Operant Behavior in Rats

    DTIC Science & Technology

    2008-02-01

    marmosets . These studies indicate that for both guinea pigs and marmosets , startle reactions increase following exposure to soman. However, it appears...Those studies utilized rats, mice, guinea pigs or marmosets as experimental subjects. In light of the abundance of reports on the disruption of...efficacy of single or repeated HI-6 treatment following soman poisoning in guinea pigs and marmoset monkeys, Toxicology 112 (1996) 183-194. [9] E.K

  13. Social defeat stress produces prolonged alterations in acoustic startle and body weight gain in male Long Evans rats.

    PubMed

    Pulliam, John V K; Dawaghreh, Ahmad M; Alema-Mensah, Ernest; Plotsky, Paul M

    2010-01-01

    Individuals exposed to psychological stressors may experience a long-term resetting of behavioral and neuroendocrine aspects of their "stress response" so that they either hyper or hypo-respond to subsequent stressors. These effects of psychological or traumatic stressors may be mimicked in rats using the resident-intruder model of social defeat. The social defeat model has been characterized to model aspects of the physiology and behavior associated with anxiety and depression. The objective of this study was to determine if behaviors elicited following repeated social defeat can also reflect aspects of ethologically relevant stresses associated with existing post traumatic stress disorder (PTSD) models. Socially defeated rats displayed weight loss and an enhanced and prolonged response to acoustic startle which was displayed for up to 10days following repeated social defeat. These data indicate that the severe stress of social defeat can produce physiologic and behavioral outcomes which may reflect aspects of traumatic psychosocial stress.

  14. History of chronic stress modifies acute stress-evoked fear memory and acoustic startle in male rats.

    PubMed

    Schmeltzer, Sarah N; Vollmer, Lauren L; Rush, Jennifer E; Weinert, Mychal; Dolgas, Charles M; Sah, Renu

    2015-01-01

    Chronicity of trauma exposure plays an important role in the pathophysiology of posttraumatic stress disorder (PTSD). Thus, exposure to multiple traumas on a chronic scale leads to worse outcomes than acute events. The rationale for the current study was to investigate the effects of a single adverse event versus the same event on a background of chronic stress. We hypothesized that a history of chronic stress would lead to worse behavioral outcomes than a single event alone. Male rats (n = 14/group) were exposed to either a single traumatic event in the form of electric foot shocks (acute shock, AS), or to footshocks on a background of chronic stress (chronic variable stress-shock, CVS-S). PTSD-relevant behaviors (fear memory and acoustic startle responses) were measured following 7 d recovery. In line with our hypothesis, CVS-S elicited significant increases in fear acquisition and conditioning versus the AS group. Unexpectedly, CVS-S elicited reduced startle reactivity to an acoustic stimulus in comparison with the AS group. Significant increase in FosB/ΔFosB-like immunostaining was observed in the dentate gyrus, basolateral amygdala and medial prefrontal cortex of CVS-S rats. Assessments of neuropeptide Y (NPY), a stress-regulatory transmitter associated with chronic PTSD, revealed selective reduction in the hippocampus of CVS-S rats. Collectively, our data show that cumulative stress potentiates delayed fear memory and impacts defensive responding. Altered neuronal activation in forebrain limbic regions and reduced NPY may contribute to these phenomena. Our preclinical studies support clinical findings reporting worse PTSD outcomes stemming from cumulative traumatization in contrast to acute trauma.

  15. Atypical antipsychotic clozapine reversed deficit on prepulse inhibition of the acoustic startle reflex produced by microinjection of DOI into the inferior colliculus in rats.

    PubMed

    de Oliveira, Rodolpho Pereira; Nagaishi, Karen Yuriko; Barbosa Silva, Regina Cláudia

    2017-05-15

    Dysfunctions of the serotonergic system have been suggested to be important in the neurobiology of schizophrenia. Patients with schizophrenia exhibit deficits in an operational measure of sensorimotor gating: prepulse inhibition (PPI) of startle. PPI is the normal reduction in the startle response caused by a low intensity non-startling stimulus (prepulse) which is presented shortly before the startle stimulus (pulse). The hallucinogen 2,5-dimethoxy-4-iodoamphetamine (DOI), a 5-hydroxytryptamine(HT)2 receptor agonist disrupted PPI in rats. The inferior colliculus (IC) is a critical nucleus of the auditory pathway mediating acoustic PPI. The activation of the IC by the acoustic prepulse reduces startle magnitude. The present study investigated the role of serotonergic transmission in the IC on the expression of acoustic PPI. For that we investigated whether 5-HT2A receptor activation or blockade would affect this response. Unilateral microinjection of DOI (10μg/0.3μl) into the IC disrupted PPI, while microinjection of the 5-HT2A receptor antagonist ritanserin (4μg/0.3μl), into this structure did not alter PPI. We also examined the ability of the atypical antipsychotic clozapine (5.0mg/kg; I.P.) to reverse the disruption of PPI produced by unilateral microinjections of DOI into the IC of rats. Pretreatment with clozapine blocked DOI-induced disruption of PPI. Altogether, these results suggest that serotonin-mediated mechanisms of the IC are involved in the expression of PPI in rodents and that this response is sensitive to atypical antipsychotic clozapine.

  16. Acoustic startle modification as a tool for evaluating auditory function of the mouse: Progress, pitfalls, and potential.

    PubMed

    Lauer, Amanda M; Behrens, Derik; Klump, Georg

    2017-03-19

    Acoustic startle response (ASR) modification procedures, especially prepulse inhibition (PPI), are increasingly used as behavioral measures of auditory processing and sensorimotor gating in rodents due to their perceived ease of implementation and short testing times. In practice, ASR and PPI procedures are extremely variable across animals, experimental setups, and studies, and the interpretation of results is subject to numerous caveats and confounding influences. We review considerations for modification of the ASR using acoustic stimuli, and we compare the sensitivity of PPI procedures to more traditional operant psychoacoustic techniques. We also discuss non-auditory variables that must be considered. We conclude that ASR and PPI measures cannot substitute for traditional operant techniques due to their low sensitivity. Additionally, a substantial amount of pilot testing must be performed to properly optimize an ASR modification experiment, negating any time benefit over operant conditioning. Nevertheless, there are some circumstances where ASR measures may be the only option for assessing auditory behavior, such as when testing mouse strains with early-onset hearing loss or learning impairments.

  17. Modulation of the N170 with Classical Conditioning: The Use of Emotional Imagery and Acoustic Startle in Healthy and Depressed Participants.

    PubMed

    Camfield, David A; Mills, Jessica; Kornfeld, Emma J; Croft, Rodney J

    2016-01-01

    Recent studies have suggested that classical conditioning may be capable of modulating early sensory processing in the human brain, and that there may be differences in the magnitude of the conditioned changes for individuals with major depressive disorder. The effect of conditioning on the N170 event-related potential was investigated using neutral faces as conditioned stimuli (CS+) and emotional imagery and acoustic startle as unconditioned stimuli (UCS). In the first experiment, electroencephalogram was recorded from 24 undergraduate students (M = 21.07 years, SD = 3.38 years) under the following conditions: (i) CS+/aversive imagery, (ii) CS+/aversive imagery and acoustic startle, (iii) CS+/acoustic startle, and (iv) CS+/pleasant imagery. The amplitude of the N170 was enhanced following conditioning with aversive imagery as well as acoustic startle. In the second experiment, 26 healthy control participants were tested (17 females and 9 males, age M = 25.97 years, SD = 9.42) together with 18 depressed participants (13 females and 5 males, age M = 23.26 years, SD = 4.01) and three conditions were used: CS+/aversive imagery, CS+/pleasant imagery, and CS-. N170 amplitude at P7 was increased for the CS+/aversive condition in comparison to CS- in the conditioning blocks versus baseline. No differences between depressed and healthy participants were found. Across both experiments, evaluative conditioning was absent. It was concluded that aversive UCS are capable of modulating early sensory processing of faces, although further research is also warranted in regards to positive UCS.

  18. Modulation of the N170 with Classical Conditioning: The Use of Emotional Imagery and Acoustic Startle in Healthy and Depressed Participants

    PubMed Central

    Camfield, David A.; Mills, Jessica; Kornfeld, Emma J.; Croft, Rodney J.

    2016-01-01

    Recent studies have suggested that classical conditioning may be capable of modulating early sensory processing in the human brain, and that there may be differences in the magnitude of the conditioned changes for individuals with major depressive disorder. The effect of conditioning on the N170 event-related potential was investigated using neutral faces as conditioned stimuli (CS+) and emotional imagery and acoustic startle as unconditioned stimuli (UCS). In the first experiment, electroencephalogram was recorded from 24 undergraduate students (M = 21.07 years, SD = 3.38 years) under the following conditions: (i) CS+/aversive imagery, (ii) CS+/aversive imagery and acoustic startle, (iii) CS+/acoustic startle, and (iv) CS+/pleasant imagery. The amplitude of the N170 was enhanced following conditioning with aversive imagery as well as acoustic startle. In the second experiment, 26 healthy control participants were tested (17 females and 9 males, age M = 25.97 years, SD = 9.42) together with 18 depressed participants (13 females and 5 males, age M = 23.26 years, SD = 4.01) and three conditions were used: CS+/aversive imagery, CS+/pleasant imagery, and CS-. N170 amplitude at P7 was increased for the CS+/aversive condition in comparison to CS- in the conditioning blocks versus baseline. No differences between depressed and healthy participants were found. Across both experiments, evaluative conditioning was absent. It was concluded that aversive UCS are capable of modulating early sensory processing of faces, although further research is also warranted in regards to positive UCS. PMID:27445773

  19. Volumetric Acoustic Vector Intensity Probe

    NASA Technical Reports Server (NTRS)

    Klos, Jacob

    2006-01-01

    A new measurement tool capable of imaging the acoustic intensity vector throughout a large volume is discussed. This tool consists of an array of fifty microphones that form a spherical surface of radius 0.2m. A simultaneous measurement of the pressure field across all the microphones provides time-domain near-field holograms. Near-field acoustical holography is used to convert the measured pressure into a volumetric vector intensity field as a function of frequency on a grid of points ranging from the center of the spherical surface to a radius of 0.4m. The volumetric intensity is displayed on three-dimensional plots that are used to locate noise sources outside the volume. There is no restriction on the type of noise source that can be studied. The sphere is mobile and can be moved from location to location to hunt for unidentified noise sources. An experiment inside a Boeing 757 aircraft in flight successfully tested the ability of the array to locate low-noise-excited sources on the fuselage. Reference transducers located on suspected noise source locations can also be used to increase the ability of this device to separate and identify multiple noise sources at a given frequency by using the theory of partial field decomposition. The frequency range of operation is 0 to 1400Hz. This device is ideal for the study of noise sources in commercial and military transportation vehicles in air, on land and underwater.

  20. Age- and Sex-Dependent Effects of Footshock Stress on Subsequent Alcohol Drinking and Acoustic Startle Behavior in Mice Selectively Bred for High-Alcohol Preference

    PubMed Central

    Chester, Julia A.; Barrenha, Gustavo D.; Hughes, Matthew L.; Keuneke, Kelly J.

    2015-01-01

    Background Exposure to stress during adolescence is known to be a risk factor for alcohol-use and anxiety disorders. This study examined the effects of footshock stress during adolescence on subsequent alcohol drinking in male and female mice selectively bred for high-alcohol preference (HAP1 lines). Acoustic startle responses and prepulse inhibition (PPI) were also assessed in the absence of, and immediately following, subsequent footshock stress exposures to determine whether a prior history of footshock stress during adolescence would produce enduring effects on anxiety-related behavior and sensorimotor gating. Methods Alcohol-nav̈ve, adolescent (male, n = 27; female, n = 23) and adult (male, n = 30; female, n = 30) HAP1 mice were randomly assigned to a stress or no stress group. The study consisted of 5 phases: (1) 10 consecutive days of exposure to a 30-minute footshock session, (2) 1 startle test, (3) one 30-minute footshock session immediately followed by 1 startle test, (4) 30 days of free-choice alcohol consumption, and (5) one 30-minute footshock session immediately followed by 1 startle test. Results Footshock stress exposure during adolescence, but not adulthood, robustly increased alcohol drinking behavior in both male and female HAP1 mice. Before alcohol drinking, females in both the adolescent and adult stress groups showed greater startle in phases 2 and 3; whereas males in the adolescent stress group showed greater startle only in phase 3. After alcohol drinking, in phase 5, enhanced startle was no longer apparent in any stress group. Males in the adult stress group showed reduced startle in phases 2 and 5. PPI was generally unchanged, except that males in the adolescent stress group showed increased PPI in phase 3 and females in the adolescent stress group showed decreased PPI in phase 5. Conclusions Adolescent HAP1 mice appear to be more vulnerable to the effects of footshock stress than adult mice, as manifested by increased alcohol drinking

  1. Gap-Prepulse Inhibition of the Acoustic Startle Reflex (GPIAS) for Tinnitus Assessment: Current Status and Future Directions

    PubMed Central

    Galazyuk, Alexander; Hébert, Sylvie

    2015-01-01

    The progress in the field of tinnitus largely depends on the development of a reliable tinnitus animal model. Recently, a new method based on the acoustic startle reflex modification was introduced for tinnitus screening in laboratory animals. This method was enthusiastically adopted and now widely used by many scientists in the field due to its seeming simplicity and a number of advantages over the other methods of tinnitus assessment. Furthermore, this method opened an opportunity for tinnitus assessment in humans as well. Unfortunately, multiple modifications of data collection and interpretation implemented in different labs make comparisons across studies very difficult. In addition, recent animal and human studies have challenged the original “filling-in” interpretation of the paradigm. Here, we review the current literature to emphasize on the commonalities and differences in data collection and interpretation across laboratories that are using this method for tinnitus assessment. We also propose future research directions that could be taken in order to establish whether or not this method is warranted as an indicator of the presence of tinnitus. PMID:25972836

  2. Prefrontal oxygenation and the acoustic startle eyeblink response during exercise: A test of the dual-mode model.

    PubMed

    Tempest, Gavin D; Parfitt, Gaynor

    2017-03-30

    The interplay between the prefrontal cortex and amygdala is proposed to explain the regulation of affective responses (pleasure/displeasure) during exercise as outlined in the dual-mode model. However, due to methodological limitations the dual-mode model has not been fully tested. In this study, prefrontal oxygenation (using near-infrared spectroscopy) and amygdala activity (reflected by eyeblink amplitude using acoustic startle methodology) were recorded during exercise standardized to metabolic processes: 80% of ventilatory threshold (below VT), at the VT, and at the respiratory compensation point (RCP). Self-reported tolerance of the intensity of exercise was assessed prior to, and affective responses recorded during exercise. The results revealed that, as the intensity of exercise became more challenging (from below VT to RCP), prefrontal oxygenation was larger and eyeblink amplitude and affective responses were reduced. Below VT and at VT, larger prefrontal oxygenation was associated with larger eyeblink amplitude. At the RCP, prefrontal oxygenation was greater in the left than right hemisphere, and eyeblink amplitude explained significant variance in affective responses (with prefrontal oxygenation) and self-reported tolerance. These findings highlight the role of the prefrontal cortex and potentially the amygdala in the regulation of affective (particularly negative) responses during exercise at physiologically challenging intensities (above VT). In addition, a psychophysiological basis of self-reported tolerance is indicated. This study provides some support of the dual-mode model and insight into the neural basis of affective responses during exercise.

  3. The medial septum mediates impairment of prepulse inhibition of acoustic startle induced by a hippocampal seizure or phencyclidine.

    PubMed

    Ma, Jingyi; Shen, Bixia; Rajakumar, N; Leung, L Stan

    2004-11-05

    The involvement of the septohippocampal system on the impaired sensorimotor gating induced by phencyclidine (PCP) or by an electrically induced hippocampal seizure was examined in behaving rats. An impaired sensorimotor gating, measured by prepulse inhibition (PPI) of the acoustic startle response, was observed following a hippocampal afterdischarge (AD) or systemic injection of PCP and was accompanied with an increase in hippocampal gamma waves (30-70 Hz). The medial septum infusion with muscimol (0.25 microg), a GABA(A) receptor agonist, 15 min prior to PCP or a hippocampal AD, prevented the impairment of sensorimotor gating and the increase in gamma waves. By itself, muscimol (0.25 microg) injection into the medial septum did not affect PPI, although it significantly suppressed spontaneous gamma waves. In order to identify subpopulations of neurons mediating the sensorimotor gating deficit and the hippocampal gamma wave increase, 0.14-0.21 microg of p75 antibody conjugated to saporin (192 IgG-saporin) was injected into the medial septum to selectively lesion the septohippocampal cholinergic neurons. Neither the PPI deficit nor the gamma wave increase induced by PCP or a hippocampal AD was affected by 192 IgG-saporin lesion of the medial septum. It is concluded that increase in neural activity in the medial septum participates in the impairment of sensorimotor gating and the increase in hippocampal gamma waves induced by PCP or a hippocampal AD. It is suggested that the GABAergic but not the cholinergic septohippocampal neurons mediate the sensorimotor gating deficit.

  4. Effects of cocaine self-administration history under limited and extended access conditions on in vivo striatal dopamine neurochemistry and acoustic startle in rhesus monkeys

    PubMed Central

    Henry, Porche’ Kirkland; Davis, Michael

    2009-01-01

    Rationale The transition from infrequent and controlled cocaine use to dependence may involve enduring changes in neurobiology as a consequence of persistent drug use. Objective The present study utilized an intravenous drug self-administration protocol of increasing cocaine access to evaluate potential changes in dopamine function in vivo, including changes in sensitivity to psychostimulants. Materials and methods Drug-naïve rhesus monkeys were provided limited access (1 h) to cocaine self-administration for 60 days followed by 60 days under an extended access condition (4 h). Basal levels of striatal extracellular dopamine and its metabolites, as well as the effectiveness of cocaine and amphetamine to elevate dopamine, were determined with in vivo microdialysis before the initiation of cocaine self-administration and during limited and extended access. The effect of cocaine and amphetamine on the acoustic startle response was also examined to assess complementary behavioral changes as a function of drug history. Results Extended access to cocaine self-administration lead to increased daily intake compared to limited access conditions but did not result in escalated intake over time. However, cocaine- and amphetamine-induced increases in striatal dopamine were diminished as a function of cocaine self-administration history. Surprisingly, there was no effect of drug-taking history on sensitivity to psychostimulant-induced enhancement of startle amplitude. Conclusions The present experiments provide evidence of a hypofunctional dopamine system that is not associated with an escalation in drug intake or reflected in measures of acoustic startle. PMID:19365621

  5. Relationship of the Acoustic Startle Response and Its Modulation to Emotional and Behavioral Problems in Typical Development Children and Those with Autism Spectrum Disorders.

    PubMed

    Takahashi, Hidetoshi; Komatsu, Sahoko; Nakahachi, Takayuki; Ogino, Kazuo; Kamio, Yoko

    2016-02-01

    Auditory hyper-reactivity is a common sensory-perceptual abnormality in autism spectrum disorders (ASD), which interrupts behavioral adaptation. We investigated acoustic startle response (ASR) modulations in 17 children with ASD and 27 with typical development (TD). Compared to TD, children with ASD had larger ASR magnitude to weak stimuli and more prolonged peak startle-latency. We could not find significant difference of prepulse inhibition (PPI) or habituation in ASD children compared to TD. However, habituation and PPI at 70-dB prepulses were negatively related to several subscales of Social Responsiveness Scale and the Strengths and Difficulties Questionnaire, when considering all children. Comprehensive investigation of ASR and its modulation might increase understanding of the neurophysiological impairments underlying ASD and other mental health problems in children.

  6. Startle modulation during emotional anticipation and perception

    PubMed Central

    Sege, Christopher T.; Bradley, Margaret M.; Lang, Peter J.

    2014-01-01

    The startle reflex is potentiated when anticipating emotional, compared to neutral, pictures. This study investigated the time course of reflex modulation during anticipation and the impact of informative cuing on picture perception. Colors were used to signal the thematic content of emotional and neutral scenes; blink response modulation was measured by presenting acoustic startle probes 3, 2, or 1 second before picture onset or 2 seconds after picture onset. During anticipation of neutral scenes, blink magnitude showed increasing attenuation as picture onset approached, consistent with a modality-directed vigilance account. Conversely, when anticipating emotional scenes, reflex magnitude did not change over time, and blinks elicited closest to picture onset were potentiated compared to neutral. During perception, the expected reflex potentiation for unpleasant pictures was not found, suggesting that cuing may dampen defensive activation. PMID:24980898

  7. Nicotine withdrawal disrupts both foreground and background contextual fear conditioning but not pre-pulse inhibition of the acoustic startle response in C57BL/6 mice.

    PubMed

    André, Jessica M; Gulick, Danielle; Portugal, George S; Gould, Thomas J

    2008-07-19

    Nicotine withdrawal is associated with multiple symptoms such as anxiety, increased appetite, and disrupted cognition in humans. Although animal models have provided insights into the somatic and affective symptoms of nicotine withdrawal, less research has focused on the effects of nicotine withdrawal on cognition. Therefore, in this study, C57BL/6J mice were used to test the effects of withdrawal from chronic nicotine on foreground and background contextual fear conditioning, which present the context as a primary or secondary stimulus, respectively. Mice withdrawn from 12 days of chronic nicotine (6.3mg/kg/day) or saline were trained and tested in either foreground or background contextual fear conditioning; nicotine withdrawal-associated deficits in contextual fear conditioning were observed in both conditions. Mice were also tested for the effects of withdrawal on pre-pulse inhibition of the acoustic startle reflex (PPI), a measure of sensory gating, and on the acoustic startle reflex. Mice withdrawn from 12 days of chronic nicotine (6.3 or 12.6 mg/kg/day) or saline underwent one 30-min PPI and startle session; no effect of withdrawal from chronic nicotine on PPI or startle was observed for either dose at 24h after nicotine removal. Therefore, mice were tested at different time points following withdrawal from 12.6 mg/kg/day chronic nicotine (8, 24, and 48 h after nicotine removal). No effect of withdrawal from chronic nicotine was observed at any time point for PPI. Overall, these results demonstrate that nicotine withdrawal disrupts two methods of contextual learning but not sensory gating in C57BL/6J mice.

  8. Structural and functional abnormalities of the hippocampal formation in rats with environmentally induced reductions in prepulse inhibition of acoustic startle.

    PubMed

    Greene, J R; Kerkhoff, J E; Guiver, L; Totterdell, S

    2001-01-01

    The effects of social isolation on prepulse inhibition of acoustic startle (PPI), electrophysiology and morphology of subicular pyramidal neurons and the densities of interneuronal sub-types in the hippocampal formation were examined. Wistar rats (male weanlings) were housed socially (socials, n=8) or individually (isolates, n=7). When tested eight weeks later, PPI was lower in isolates. Rats then received terminal anaesthesia before slices of hippocampal formation were made in which the electrophysiological properties of a total of 108 subicular neurons were characterized. There were no differences in neuronal sub-types recorded in socials compared with isolates. Intrinsically burst-firing and regular spiking pyramidal neurons were examined in detail. There were no differences in resting membrane potential or input resistance in isolates compared with socials but action potential height was reduced and action potential threshold raised in isolates. A limited morphological examination of Neurobiotin-filled intrinsically burst-firing neurons did not reveal differences in cell-body area or in number of primary dendrites. Sections from the contralateral hemispheres of the same rats were stained with antibodies to calretinin, parvalbumin and the neuronal isoform of nitric oxide synthase (nNOS). In isolates, the density of calretinin positive neurons was increased in the dentate gyrus but unchanged in areas CA3, CA1 and subiculum. Parvalbumin and nNOS positive neuronal densities were unchanged. Hence in rats with environmentally induced reductions in PPI there are structural and functional abnormalities in the hippocampal formation. If the reduction in PPI stems from these abnormalities, and reduced PPI in rats is relevant to schizophrenia, then drugs that correct the reported electrophysiological changes might have antipsychotic effects.

  9. Different Effects of Startling Acoustic Stimuli (SAS) on TMS-Induced Responses at Rest and during Sustained Voluntary Contraction.

    PubMed

    Chen, Yen-Ting; Li, Shengai; Zhou, Ping; Li, Sheng

    2016-01-01

    Previous studies have shown that a habituated startling acoustic stimulus (SAS) can cause a transient suppression of motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS) during light muscle contraction. However, it is still unknown whether this phenomenon persists when at rest or during a sustained voluntary contraction task. Therefore, the purpose of this study was to determine whether a conditioning SAS has different effects. TMS was delivered to the hot spot for the left biceps on 11 subjects at rest both with and without a conditioning SAS. Of the 11subjects, 9 also had TMS delivered during isometric flexion of the left elbow, also with and without a conditioning SAS. TMS-induced MEPs, TMS-induced force, and silent periods were used to determine the effect of conditioning SAS. Consistent with previous findings, TMS-induced MEPs were smaller with a conditioning SAS (0.49 ± 0.37 mV) as compared without the SAS (0.69 ± 0.52 mV) at rest. However, a conditioning SAS during the voluntary contraction tasks resulted in a significant shortening of the MEP silent period (187.22 ± 22.99 ms with SAS vs. 200.56 ± 29.71 ms without SAS) without any changes in the amplitude of the MEP (1.37 ± 0.9 mV with SAS V.S. 1.32 ± 0.92 mV without SAS) or the TMS-induced force (3.11 ± 2.03 N-m with SAS V.S. 3.62 ± 1.33 N-m without SAS). Our results provide novel evidence that a conditioning SAS has different effects on the excitability of the motor cortex when at rest or during sustained voluntary contractions.

  10. Different Effects of Startling Acoustic Stimuli (SAS) on TMS-Induced Responses at Rest and during Sustained Voluntary Contraction

    PubMed Central

    Chen, Yen-Ting; Li, Shengai; Zhou, Ping; Li, Sheng

    2016-01-01

    Previous studies have shown that a habituated startling acoustic stimulus (SAS) can cause a transient suppression of motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS) during light muscle contraction. However, it is still unknown whether this phenomenon persists when at rest or during a sustained voluntary contraction task. Therefore, the purpose of this study was to determine whether a conditioning SAS has different effects. TMS was delivered to the hot spot for the left biceps on 11 subjects at rest both with and without a conditioning SAS. Of the 11subjects, 9 also had TMS delivered during isometric flexion of the left elbow, also with and without a conditioning SAS. TMS-induced MEPs, TMS-induced force, and silent periods were used to determine the effect of conditioning SAS. Consistent with previous findings, TMS-induced MEPs were smaller with a conditioning SAS (0.49 ± 0.37 mV) as compared without the SAS (0.69 ± 0.52 mV) at rest. However, a conditioning SAS during the voluntary contraction tasks resulted in a significant shortening of the MEP silent period (187.22 ± 22.99 ms with SAS vs. 200.56 ± 29.71 ms without SAS) without any changes in the amplitude of the MEP (1.37 ± 0.9 mV with SAS V.S. 1.32 ± 0.92 mV without SAS) or the TMS-induced force (3.11 ± 2.03 N-m with SAS V.S. 3.62 ± 1.33 N-m without SAS). Our results provide novel evidence that a conditioning SAS has different effects on the excitability of the motor cortex when at rest or during sustained voluntary contractions. PMID:27547181

  11. Dynamics of intracellular dopamine contents in the rat brain during the formation of conditioned contextual fear and extinction of an acoustic startle reaction.

    PubMed

    Storozheva, Z I; Afanas'ev, I I; Proshin, A T; Kudrin, V S

    2003-05-01

    Extracellular dopamine contents in the caudate nucleus, nucleus accumbens, and prefrontal cortex of the rat brain were measured during two sessions of extinction of an acoustic startle reaction--each consisting of ten sound stimuli, the two sessions separated by 24 h--with simultaneous recording of freezing behavior. The results demonstrated a decrease in extracellular dopamine levels in the caudate nucleus and an increase in the nucleus accumbens during both sessions of extinction, with return to initial immediately after sessions ended. During the second session, the amplitude of startle responses and the magnitude of changes in dopamine levels in both structures were significantly smaller than during the first session. Between the sessions, dopamine levels in the caudate nucleus remained constant, while those in the nucleus accumbens decreased. The prefrontal cortex showed increases in dopamine levels during both sessions of extinction, as well as between the two sessions. The amplitude of the startle reaction was found to correlate with dopamine levels in the prefrontal cortex after the end of the corresponding extinction session and with the dopamine level before the start of the second session. The freezing time before the start of sound stimulation in the second session, this being a measure of conditioned fear, correlated with the dopamine level in the caudate nucleus on the training day and with the dopamine level in the nucleus accumbens before the start of the second session. The role of the dopaminergic system in the mechanisms forming and realizing the various components of defensive behavior are discussed.

  12. Fluorocarbon nanodrops as acoustic temperature probes.

    PubMed

    Mountford, Paul A; Smith, William S; Borden, Mark A

    2015-10-06

    This work investigated the use of superheated fluorocarbon nanodrops for ultrasound thermal imaging and the use of mixed fluorocarbons for tuning thermal and acoustic thresholds for vaporization. Droplets were fabricated by condensing phospholipid-coated microbubbles containing C3F8 and C4F10 mixed at various molar ratios. Vaporization temperatures first were measured in a closed system by optical transmission following either isothermal pressure release or isobaric heating. The vaporization temperature was found to depend linearly on the percentage of C4F10 in the droplet core, indicating excellent tunability under these fluorocarbon-saturated conditions. Vaporization temperatures were then measured in an open system using contrast-enhanced ultrasound imaging, where it was found that the mixed droplets behaved like pure C4F10 drops. Additionally, the critical mechanical index for vaporization was measured at the limits of therapeutic hyperthermia (37 and 60 °C), and again the mixed droplets were found to behave like pure C4F10 drops. These results suggested that C3F8 preferentially dissolves out of the droplet core in open systems, as shown by a simple mass transfer model of multicomponent droplet dissolution. Finally, proof-of-concept was shown that pure C4F10 nanodrops can be used as an acoustic temperature probe. Overall, these results not only demonstrate the potential of superheated fluorocarbon emulsions for sonothermetry but also point to the limits of tunability for fluorocarbon mixtures owing to preferential release of the more soluble species to the atmosphere.

  13. Acoustics of the piezo-electric pressure probe

    NASA Technical Reports Server (NTRS)

    Dutt, G. S.

    1974-01-01

    Acoustical properties of a piezoelectric device are reported for measuring the pressure in the plasma flow from an MPD arc. A description and analysis of the acoustical behavior in a piezoelectric probe is presented for impedance matching and damping. The experimental results are presented in a set of oscillographic records.

  14. Nondestructive acoustic electric field probe apparatus and method

    DOEpatents

    Migliori, Albert

    1982-01-01

    The disclosure relates to a nondestructive acoustic electric field probe and its method of use. A source of acoustic pulses of arbitrary but selected shape is placed in an oil bath along with material to be tested across which a voltage is disposed and means for receiving acoustic pulses after they have passed through the material. The received pulses are compared with voltage changes across the material occurring while acoustic pulses pass through it and analysis is made thereof to determine preselected characteristics of the material.

  15. Probing Acoustic Nonlinearity by Mixing Surface Acoustic Waves

    SciTech Connect

    Hurley, David Howard; Telschow, Kenneth Louis

    2000-07-01

    Measurement methods aimed at determining material properties through nonlinear wave propagation are sensitive to artifacts caused by background nonlinearities inherent in the ultrasonic generation and detection methods. The focus of this paper is to describe our investigation of nonlinear mixing of surface acoustic waves (SAWs) as a means to decrease sensitivity to background nonlinearity and increase spatial sensitivity to acoustic nonlinearity induced by material microstructure.

  16. Prediction and Perception: Defensive Startle Modulation

    PubMed Central

    Sege, Christopher T.; Bradley, Margaret M.; Lang, Peter J.

    2015-01-01

    Previous research indicates that predictive cues can dampen subsequent defensive reactions. The present study investigated whether effects of cuing are specific to aversive stimuli, using modulation of the blink startle reflex as a measure of emotional reactivity. Participants viewed pictures depicting violence, romance/ erotica, or mundane content. On half of all trials, a cue (color) predicted the content of the upcoming picture; on the remaining trials, scenes were presented without a cue. Acoustic startle probes were presented during picture viewing on trials with predictive cues and trials without a cue. Replicating previous studies, blink reflexes elicited when viewing violent pictures that had not been preceded by a cue were potentiated compared to un-cued mundane scenes, and reflexes were attenuated when viewing scenes of erotica/ romance that had not been cued. On the other hand, reflex potentiation when viewing scenes of violence (relative to mundane scenes) was eliminated when these pictures were preceded by a predictive cue, whereas scenes of romance prompted reliable reflex attenuation regardless of whether pictures were cued or not. Taken together, the data suggest that cuing elicits an anticipatory coping process that is specific to aversive stimuli. PMID:26399464

  17. The serotonin transporter gene and startle response during nicotine deprivation.

    PubMed

    Minnix, Jennifer A; Robinson, Jason D; Lam, Cho Y; Carter, Brian L; Foreman, Jennifer E; Vandenbergh, David J; Tomlinson, Gail E; Wetter, David W; Cinciripini, Paul M

    2011-01-01

    Affective startle probe methodology was used to examine the effects of nicotine administration and deprivation on emotional processes among individuals carrying at least one s allele versus those with the l/l genotype of the 5-Hydroxytryptamine (Serotonin) Transporter Linked Polymorphic Region, 5-HTTLPR in the promoter region of the serotonin transporter gene [solute ligand carrier family 6 member A4 (SLC6A4) or SERT]. Smokers (n=84) completed four laboratory sessions crossing deprivation (12-h deprived vs. non-deprived) with nicotine spray (nicotine vs. placebo). Participants viewed affective pictures (positive, negative, neutral) while acoustic startle probes were administered. We found that smokers with the l/l genotype showed significantly greater suppression of the startle response when provided with nicotine vs. placebo than those with the s/s or s/l genotypes. The results suggest that l/l smokers, who may have higher levels of the serotonin transporter and more rapid synaptic serotonin clearance, experience substantial reduction in activation of the defensive system when exposed to nicotine.

  18. Behavioral consequences of radiation exposure to simulated space radiation in the C57BL/6 mouse: open field, rotorod, and acoustic startle

    NASA Technical Reports Server (NTRS)

    Pecaut, Michael J.; Haerich, Paul; Zuccarelli, Cara N.; Smith, Anna L.; Zendejas, Eric D.; Nelson, Gregory A.

    2002-01-01

    Two experiments were carried out to investigate the consequences of exposure to proton radiation, such as might occur for astronauts during space flight. C57BL/6 mice were exposed, either with or without 15-g/cm2 aluminum shielding, to 0-, 3-, or 4-Gy proton irradiation mimicking features of a solar particle event. Irradiation produced transient direct deficits in open-field exploratory behavior and acoustic startle habituation. Rotorod performance at 18 rpm was impaired by exposure to proton radiation and was impaired at 26 rpm, but only for mice irradiated with shielding and at the 4-Gy dose. Long-term (>2 weeks) indirect deficits in open-field activity appeared as a result of impaired experiential encoding immediately following exposure. A 2-week recovery prior to testing decreased most of the direct effects of exposure, with only rotorod performance at 26 rpm being impaired. These results suggest that the performance deficits may have been mediated by radiation damage to hippocampal, cerebellar, and possibly, forebrain dopaminergic function.

  19. Probing Cell Deformability via Acoustically Actuated Bubbles

    PubMed Central

    Xie, Yuliang; Nama, Nitesh; Li, Peng; Mao, Zhangming; Huang, Po-Hsun; Zhao, Chenglong; Costanzo, Francesco; Huang, Tony Jun

    2016-01-01

    An acoustically actuated, bubble-based technique is developed to investigate the deformability of cells suspended in microfluidic devices. A microsized bubble is generated by an optothermal effect near the targeted cells, which are suspended in a microfluidic chamber. Subsequently, acoustic actuation is employed to create localized acoustic streaming. In turn, the streaming flow results in hydrodynamic forces that deform the cells in situ. The deformability of the cells is indicative of their mechanical properties. The method in this study measures mechanical biomarkers from multiple cells in a single experiment, and it can be conveniently integrated with other bioanalysis and drug-screening platforms. Using this technique, the mean deformability of tens of HeLa, HEK, and HUVEC cells is measured to distinguish their mechanical properties. HeLa cells are deformed upon treatment with Cytochalasin. The technique also reveals the deformability of each subpopulation in a mixed, heterogeneous cell sample by the use of both fluorescent markers and mechanical biomarkers. The technique in this study, apart from being relevant to cell biology, will also enable biophysical cellular diagnosis. PMID:26715211

  20. Variables involved in the cue modulation of the startle reflex in alcohol-dependent patients.

    PubMed

    Rubio, Gabriel; Borrell, José; Jiménez, Mónica; Jurado, Rosa; Grüsser, Sabine M; Heinz, Andreas

    2013-01-01

    Cue modulation of the startle reflex is a paradigm that has been used to understand the emotional mechanisms involved in alcohol dependence. Attenuation of the startle reflex has been demonstrated when alcohol-dependent subjects are exposed to alcohol-related stimuli. However, the role of clinical variables on the magnitude of this response is unknown. The objective of this study was to determine the relationship between a number of clinical variables-severity of alcoholism, family history of alcoholism (FHA+), personality traits related to the sensitivity to reward-and the startle reflex response when subjects with alcohol dependence were viewing alcohol-related cues. After detoxification, 98 participants completed self-report instruments and had eye blink electromyograms measured to acoustic startle probes [100-millisecond burst of white noise at 95 dB(A)] while viewing alcohol-related pictures, and standardised appetitive, aversive and neutral control scenes. Ninety-eight healthy controls were also assessed with the same instruments. There were significant differences on alcohol-startle magnitude between patients and controls. Comparisons by gender showed that women perceived alcohol cues and appetitive cues more appetitive than men. Male and female patients showed more appetitive responses to alcohol cues when compared with their respective controls. Our patients showed an appetitive effect of alcohol cues that was positively related to severity of alcohol dependence, sensitivity to reward and a FHA+. The data confirmed that the pattern of the modulation of the acoustic startle reflex reveals appetitive effects of the alcohol cues and extended it to a variety of clinical variables.

  1. Acoustic Probe for Solid-Gas-Liquid Suspension

    SciTech Connect

    Tavlarides, L.L.; Sangani, Ashok

    2003-09-14

    The primary objective of the research project during the first funding period was to develop an acoustic probe to measure volume percent solids in solid-liquid slurries in the presence of small amounts of gas bubbles. This problem was addressed because of the great need for a non-invasive, accurate and reliable method for solids monitoring in liquid slurries in the presence of radiolytically generated gases throughout the DOE complex. These measurements are necessary during mobilization of salts and sediments in tanks, transport of these slurries in transfer lines to processing facilities across a site, and, in some instances, during high level waste processing. Although acoustic probes have been commonly used for monitoring flows in single-phase fluids (McLeod, 1967), their application to monitor two-phase mixtures has not yet fully realized its potential. A number of investigators in recent years have therefore been involved in developing probes for measuring the volume fractions in liquid solid suspensions (Atkinson and Kytomaa, 1993; Greenwood et al., 1993; Martin et al., 1995) and in liquid-liquid suspensions (Bonnet and Tavlarides, 1987; Tavlarides and Bonnet, 1988, Yi and Tavlarides, 1990; Tsouris and Tavlarides, 1993, Tsouris et al., 1995). In particular, Atkinson and Kytomaa (1993) showed that the acoustic technique can be used to determine both the velocity and the volume fraction of solids while Martin et al. (1995) and Spelt et al. (1999) showed that the acoustic probe can also be used to obtain information on the size distribution of the particles. In a recent testing of in-line slurry monitors with radioactive slurries suspended with Pulsair Mixers (Hylton & Bayne, 1999), an acoustic probe did not compare well with other instruments most probably due to presence of entrained gases and improper acoustic frequency range of interrogation. The work of the investigators cited has established the potential of the acoustic probe for characterizing

  2. Morphological correlates of sex differences in acoustic startle response and prepulse inhibition through projections from locus coeruleus to cochlear root neurons.

    PubMed

    Hormigo, Sebastian; Gómez-Nieto, Ricardo; Sancho, Consuelo; Herrero-Turrión, Javier; Carro, Juan; López, Dolores E; Horta-Júnior, José de Anchieta de Castro E

    2017-04-05

    The noradrenergic locus coeruleus (LC) plays an important role in the promotion and maintenance of arousal and alertness. Our group recently described coerulean projections to cochlear root neurons (CRNs), the first relay of the primary acoustic startle reflex (ASR) circuit. However, the role of the LC in the ASR and its modulation, prepulse inhibition (PPI), is not clear. In this study, we damaged LC neurons and fibers using a highly selective neurotoxin, DSP-4, and then assessed ASR and PPI in male and female rats. Our results showed that ASR amplitude was higher in males at 14 days after DSP-4 injection when compared to pre-administration values and those in the male control group. Such modifications in ASR amplitude did not occur in DSP-4-injected females, which exhibited ASR amplitude within the range of control values. PPI differences between males and females seen in controls were not observed in DSP-4-injected rats for any interstimulus interval tested. DSP-4 injection did not affect ASR and PPI latencies in either the male or the female groups, showing values that were consistent with the sex-related variability observed in control rats. Furthermore, we studied the noradrenergic receptor system in the cochlear nerve root using gene expression analysis. When compared to controls, DSP-4-injected males showed higher levels of expression in all adrenoceptor subtypes; however, DSP-4-injected females showed varied effects depending on the receptor type, with either up-, downregulations, or maintenance of expression levels. Lastly, we determined noradrenaline levels in CRNs and other LC-targeted areas using HPLC assays, and these results correlated with behavioral and adrenoceptor expression changes post DSP-4 injection. Our study supports the participation of LC in ASR and PPI, and contributes toward a better understanding of sex-related differences observed in somatosensory gating paradigms.

  3. Cardiac Modulation of Startle: Effects on Eye Blink and Higher Cognitive Processing

    ERIC Educational Resources Information Center

    Schulz, Andre; Reichert, Carolin F.; Richter, Steffen; Lass-Hennemann, Johanna; Blumenthal, Terry D.; Schachinger, Hartmut

    2009-01-01

    Cardiac cycle time has been shown to affect pre-attentive brainstem startle processes, such as the magnitude of acoustically evoked reflexive startle eye blinks. These effects were attributed to baro-afferent feedback mechanisms. However, it remains unclear whether cardiac cycle time plays a role in higher startle-related cognitive processes, as…

  4. Surface acoustic wave probe implant for predicting epileptic seizures

    DOEpatents

    Gopalsami, Nachappa [Naperville, IL; Kulikov, Stanislav [Sarov, RU; Osorio, Ivan [Leawood, KS; Raptis, Apostolos C [Downers Grove, IL

    2012-04-24

    A system and method for predicting and avoiding a seizure in a patient. The system and method includes use of an implanted surface acoustic wave probe and coupled RF antenna to monitor temperature of the patient's brain, critical changes in the temperature characteristic of a precursor to the seizure. The system can activate an implanted cooling unit which can avoid or minimize a seizure in the patient.

  5. Startle Modulation Studies in Autism.

    ERIC Educational Resources Information Center

    Ornitz, Edward M.; And Others

    1993-01-01

    Analysis of 54 autistic patients and 72 controls found no intergroup differences in startle modulation by inhibitory or facilitatory prestimulation, short-term habituation of startle amplitude, long-term habituation of startle amplitude or latency, or unmodulated startle amplitude. Differences included prolongation of unmodulated startle onset…

  6. Micromachined fiber optic Fabry-Perot underwater acoustic probe

    NASA Astrophysics Data System (ADS)

    Wang, Fuyin; Shao, Zhengzheng; Hu, Zhengliang; Luo, Hong; Xie, Jiehui; Hu, Yongming

    2014-08-01

    One of the most important branches in the development trend of the traditional fiber optic physical sensor is the miniaturization of sensor structure. Miniature fiber optic sensor can realize point measurement, and then to develop sensor networks to achieve quasi-distributed or distributed sensing as well as line measurement to area monitoring, which will greatly extend the application area of fiber optic sensors. The development of MEMS technology brings a light path to address the problems brought by the procedure of sensor miniaturization. Sensors manufactured by MEMS technology possess the advantages of small volume, light weight, easy fabricated and low cost. In this paper, a fiber optic extrinsic Fabry-Perot interferometric underwater acoustic probe utilizing micromachined diaphragm collaborated with fiber optic technology and MEMS technology has been designed and implemented to actualize underwater acoustic sensing. Diaphragm with central embossment, where the embossment is used to anti-hydrostatic pressure which would largely deflect the diaphragm that induce interferometric fringe fading, has been made by double-sided etching of silicon on insulator. By bonding the acoustic-sensitive diaphragm as well as a cleaved fiber end in ferrule with an outer sleeve, an extrinsic Fabry-Perot interferometer has been constructed. The sensor has been interrogated by quadrature-point control method and tested in field-stable acoustic standing wave tube. Results have been shown that the recovered signal detected by the sensor coincided well with the corresponding transmitted signal and the sensitivity response was flat in frequency range from 10 Hz to 2kHz with the value about -154.6 dB re. 1/μPa. It has been manifest that the designed sensor could be used as an underwater acoustic probe.

  7. Trait absorption is related to enhanced emotional picture processing and reduced processing of secondary acoustic probes.

    PubMed

    Benning, Stephen D; Rozalski, Vincent; Klingspon, Kara L

    2015-10-01

    Trait absorption reflects a propensity to have one's attention drawn to engaging sensory or imaginal experiences. It is related to self-reported levels of positive and negative emotionality, but little work has examined whether absorption is related to greater levels of basic emotional processing. We used the late positive potential (LPP) to pictures and P3 response to subsequent startle probes during those pictures to examine how absorption was related to initial emotional processing and reactivity to a second stimulus. Across genders, absorption was positively related to LPP amplitude to emotional versus neutral pictures at PZ, and it was negatively related to overall P3 amplitude to startle probes at FZ. Thus, absorption appears to index greater processing of emotional material at the cost of reduced processing of subsequent incoming stimuli.

  8. Design and manufacturing of scanning probe acoustic microscope test phantom

    NASA Astrophysics Data System (ADS)

    Chen, Xiaohui; Fang, Xiaoyue; Song, Jitao; Ding, Mingyue

    2015-03-01

    Acquiring nondestructive internal structures acoustic image as well as the morphology images using scanning probe acoustic microscope (SPAM) is a challenge and no known metrology tools to identify the ultrasonic internal resolution and detectable depth of SPAM in a nondestructive way. Monitoring these defects necessitates the identification of their technical parameters of SPAM. In this paper, the specific materials (test phantoms) were designed and processed so that the ultrasound internal resolution of SPAM in nondestructive imaging of the embedded or buried substructures as well as the morphology images were measured. Experimental results demonstrated the successful identification of embedded or buried defects under the test phantom with the resolution of 50nm for SPAM as well as the detectable depth of more than 100μm.

  9. Sound transmission through a high-temperature acoustic probe tube

    NASA Technical Reports Server (NTRS)

    Parrott, Tony L.; Zorumski, William E.

    1990-01-01

    An investigation was conducted of acoustic transmission through a tube subjected to an intense thermal gradient along its axis. The results are of interest in the interpretation of acoustic data from probe tube configurations designed to measure fluctuating pressures in high temperature environments. The measured transfer function across a localized heated region in the tube was compared to a computed transfer function based on a theoretical analysis of propagation through strong temperature gradients. Over the frequency range 0.4 kHz to 6.0 kHz, generally good agreement was obtained between the measured and calculated attenuation across the heated region with some discrepancy occurring at the attenuation minima. Agreement between measured and calculated phase difference was excellent to within the measurement resolution.

  10. Acoustic probe for solid-gas-liquid suspensions. 1998 annual progress report

    SciTech Connect

    Tavlarides, L.L.; Sangani, A.S.; Greenwood, M.S.

    1998-06-01

    'The proposed research will develop an acoustic probe for monitoring particle size and volume fraction in slurries in the absence and presence of gas. The goals are to commission and verify the probe components and system operation, develop theory for the forward and inverse problems for acoustic wave propagation through a three phase medium, and experimentally verify the theoretical analysis. The acoustic probe will permit measurement of solid content in gas-liquid-solid waste slurries in tanks across the DOE complex.'

  11. Pressure probe and hot-film probe rsponses to acoustic excitation in mean flow

    NASA Technical Reports Server (NTRS)

    Parrott, T. L.; Jones, M. G.

    1986-01-01

    An experiment was conducted to compare the relative responses of a hot-film probe and a pressure probe positioned in a flow duct carrying mean flow and progressive acoustic waves. The response of each probe was compared with that of a condenser-type microphone flush mounted in the duct wall for flow Mach numbers up to about 0.5. The response of the pressure probe was less than that of the flush-mounted microphone by not more than about 2.1 dB at the highest centerline Mach number. This decreased response of the probe can likely be attributed to flow-induced impedance changes at the probe sensor orifices. The response of the hot-film probe, expressed in terms of fluctuating pressure, was greater than that of the flush-mounted microphone by as much as 6.0 dB at the two higher centerline Mach numbers. Removal of the contribution from fluctuating temperature in the hot-film analytical model greatly improved the agreement between the two transducer responses.

  12. Amygdala and anterior cingulate cortex activation during affective startle modulation: a PET study of fear.

    PubMed

    Pissiota, Anna; Frans, Orjan; Michelgård, Asa; Appel, Lieuwe; Långström, Bengt; Flaten, Magne Arve; Fredrikson, Mats

    2003-09-01

    The human startle response is modulated by emotional experiences, with startle potentiation associated with negative affect. We used positron emission tomography with 15O-water to study neural networks associated with startle modulation by phobic fear in a group of subjects with specific snake or spider phobia, but not both, during exposure to pictures of their feared and non-feared objects, paired and unpaired with acoustic startle stimuli. Measurement of eye electromyographic activity confirmed startle potentiation during the phobic as compared with the non-phobic condition. Employing a factorial design, we evaluated brain correlates of startle modulation as the interaction between startle and affect, using the double subtraction contrast (phobic startle vs. phobic alone) vs. (non-phobic startle vs. non-phobic alone). As a result of startle potentiation, a significant increase in regional cerebral blood flow was found in the left amygdaloid-hippocampal region, and medially in the affective division of the anterior cingulate cortex (ACC). These results provide evidence from functional brain imaging for a modulatory role of the amygdaloid complex on startle reactions in humans. They also point to the involvement of the affective ACC in the processing of startle stimuli during emotionally aversive experiences. The co-activation of these areas may reflect increased attention to fear-relevant stimuli. Thus, we suggest that the amygdaloid area and the ACC form part of a neural system dedicated to attention and orientation to danger, and that this network modulates startle during negative affect.

  13. Startle reduces recall of a recently learned internal model.

    PubMed

    Wright, Zachary; Patton, James L; Ravichandran, Venn

    2011-01-01

    Recent work has shown that preplanned motor programs are released early from subcortical areas by the using a startling acoustic stimulus (SAS). Our question is whether this response might also contain a recently learned internal model, which draws on experience to predict and compensate for expected perturbations in a feedforward manner. Studies of adaptation to robotic forces have shown some evidence of this, but were potentially confounded by cocontraction caused by startle. We performed a new adaptation experiment using a visually distorted field that could not be confounded by cocontraction. We found that in all subjects that exhibited startle, the startle stimulus (1) reduced performance of the recently learned task (2) reduced after-effect magnitudes. Because startle reduced but did not eliminate the recall of learned control, we suggest that multiple neural centers (cortical and subcortical) are involved in such learning and adaptation, which can impact training areas such as piloting, teleoperation, sports, and rehabilitation.

  14. Cavitation controlled acoustic probe for fabric spot cleaning and moisture monitoring

    DOEpatents

    Sheen, Shuh-Haw; Chien, Hual-Te; Raptis, Apostolos C.

    1997-01-01

    A method and apparatus are provided for monitoring a fabric. An acoustic probe generates acoustic waves relative to the fabric. An acoustic sensor, such as an accelerometer is coupled to the acoustic probe for generating a signal representative of cavitation activity in the fabric. The generated cavitation activity representative signal is processed to indicate moisture content of the fabric. A feature of the invention is a feedback control signal is generated responsive to the generated cavitation activity representative signal. The feedback control signal can be used to control the energy level of the generated acoustic waves and to control the application of a cleaning solution to the fabric.

  15. Modeling startle eyeblink electromyogram to assess fear learning.

    PubMed

    Khemka, Saurabh; Tzovara, Athina; Gerster, Samuel; Quednow, Boris B; Bach, Dominik R

    2017-02-01

    Pavlovian fear conditioning is widely used as a laboratory model of associative learning in human and nonhuman species. In this model, an organism is trained to predict an aversive unconditioned stimulus from initially neutral events (conditioned stimuli, CS). In humans, fear memory is typically measured via conditioned autonomic responses or fear-potentiated startle. For the latter, various analysis approaches have been developed, but a systematic comparison of competing methodologies is lacking. Here, we investigate the suitability of a model-based approach to startle eyeblink analysis for assessment of fear memory, and compare this to extant analysis strategies. First, we build a psychophysiological model (PsPM) on a generic startle response. Then, we optimize and validate this PsPM on three independent fear-conditioning data sets. We demonstrate that our model can robustly distinguish aversive (CS+) from nonaversive stimuli (CS-, i.e., has high predictive validity). Importantly, our model-based approach captures fear-potentiated startle during fear retention as well as fear acquisition. Our results establish a PsPM-based approach to assessment of fear-potentiated startle, and qualify previous peak-scoring methods. Our proposed model represents a generic startle response and can potentially be used beyond fear conditioning, for example, to quantify affective startle modulation or prepulse inhibition of the acoustic startle response.

  16. Modeling startle eyeblink electromyogram to assess fear learning

    PubMed Central

    Khemka, Saurabh; Tzovara, Athina; Gerster, Samuel; Quednow, Boris B.

    2016-01-01

    Abstract Pavlovian fear conditioning is widely used as a laboratory model of associative learning in human and nonhuman species. In this model, an organism is trained to predict an aversive unconditioned stimulus from initially neutral events (conditioned stimuli, CS). In humans, fear memory is typically measured via conditioned autonomic responses or fear‐potentiated startle. For the latter, various analysis approaches have been developed, but a systematic comparison of competing methodologies is lacking. Here, we investigate the suitability of a model‐based approach to startle eyeblink analysis for assessment of fear memory, and compare this to extant analysis strategies. First, we build a psychophysiological model (PsPM) on a generic startle response. Then, we optimize and validate this PsPM on three independent fear‐conditioning data sets. We demonstrate that our model can robustly distinguish aversive (CS+) from nonaversive stimuli (CS‐, i.e., has high predictive validity). Importantly, our model‐based approach captures fear‐potentiated startle during fear retention as well as fear acquisition. Our results establish a PsPM‐based approach to assessment of fear‐potentiated startle, and qualify previous peak‐scoring methods. Our proposed model represents a generic startle response and can potentially be used beyond fear conditioning, for example, to quantify affective startle modulation or prepulse inhibition of the acoustic startle response. PMID:27753123

  17. Cytotoxic lesion of the medial prefrontal cortex abolishes the partial reinforcement extinction effect, attenuates prepulse inhibition of the acoustic startle reflex and induces transient hyperlocomotion, while sparing spontaneous object recognition memory in the rat.

    PubMed

    Yee, B K

    2000-01-01

    The partial reinforcement extinction effect refers to the increase in resistance to extinction of an operant response acquired under partial reinforcement relative to that acquired under continuous reinforcement. Prepulse inhibition of the acoustic startle response refers to the reduction in startle reactivity towards an intense acoustic pulse stimulus when it is shortly preceded by a weak prepulse stimulus. These two behavioural phenomena appear to be related to different forms of attentional processes. While the prepulse inhibition effect reflects an inherent early attentional gating mechanism, the partial reinforcement extinction effect is believed to involve the development of acquired inattention, i.e. the latter requires the animals to learn about what to and what not to attend. Impairments in prepulse inhibition and the partial reinforcement extinction effect have been independently linked to the neuropsychology of attentional dysfunctions seen in schizophrenia. The proposed neural substrates underlying these behaviourial phenomena also appear to overlap considerably: both focus on the nucleus accumbens and emphasize the functional importance of its limbic afferents, including that originating from the medial prefrontal cortex, on accumbal output/activity. The present study demonstrated that cytotoxic medial prefrontal cortex lesions which typically damaged the prelimbic, the infralimbic and the dorsal anterior cingulate areas could lead to the abolition of the partial reinforcement extinction effect and the attenuation of prepulse inhibition. The lesions also resulted in a transient elevation of spontaneous locomotor activity. In contrast, the same lesions spared performance in a spontaneous object recognition memory test, in which the lesioned animals displayed normal preference for a novel object when the novel object was presented in conjunction with a familiar object seen 10 min earlier within an open field arena. The present results lend support to the

  18. Affect Modulated Startle in Schizophrenia: Subjective Experience Matters

    PubMed Central

    Dominelli, Rachelle M.; Boggs, Jennifer M.; Bolbecker, Amanda R.; O'Donnell, Brian F.; Hetrick, William P.; Brenner, Colleen A.

    2014-01-01

    Data suggests that emotion reactivity as measured by the affect-modulated startle paradigm in those with schizophrenia (SZ) may be similar to healthy controls (HC). However, normative classification of the stimuli may not accurately reflect emotional experience, especially for those with SZ. To examine this possibility, the present study measured the affect-modulated startle response with images classified according to both normative and subjective ratings. Seventeen HC and 17 SZ completed an image viewing task during which startle probes were presented, followed by subjective valence and arousal ratings. Both groups exhibited inhibited startle responses to positive images, intermediate startle amplitudes to neutral images, and potentiated startle amplitudes to negative images. SZ rated the positive images as less positive than HC. When images were reclassified based on subjective valence ratings, both groups’ startle magnitudes increased in response to subjectively rated positive images and decreased to subjectively rated neutral images. The number of trials classified into each valence condition suggested a tendency for SZ to classify neutral images as negative more often than HC. Overall, these findings suggest that affective stimuli modulate the startle response in HC and SZ in similar ways, but subjective emotional experience may differ in those with schizophrenia. PMID:25107317

  19. The gap-startle paradigm for tinnitus screening in animal models: limitations and optimization.

    PubMed

    Lobarinas, Edward; Hayes, Sarah H; Allman, Brian L

    2013-01-01

    In 2006, Turner and colleagues (Behav. Neurosci., 120:188-195) introduced the gap-startle paradigm as a high-throughput method for tinnitus screening in rats. Under this paradigm, gap detection ability was assessed by determining the level of inhibition of the acoustic startle reflex produced by a short silent gap inserted in an otherwise continuous background sound prior to a loud startling stimulus. Animals with tinnitus were expected to show impaired gap detection ability (i.e., lack of inhibition of the acoustic startle reflex) if the background sound containing the gap was qualitatively similar to the tinnitus pitch. Thus, for the gap-startle paradigm to be a valid tool to screen for tinnitus, a robust startle response from which to inhibit must be present. Because recent studies have demonstrated that the acoustic startle reflex could be dramatically reduced following noise exposure, we endeavored to 1) modify the gap-startle paradigm to be more resilient in the presence of hearing loss, and 2) evaluate whether a reduction in startle reactivity could confound the interpretation of gap prepulse inhibition and lead to errors in screening for tinnitus. In the first experiment, the traditional broadband noise (BBN) startle stimulus was replaced by a bandpass noise in which the sound energy was concentrated in the lower frequencies (5-10 kHz) in order to maintain audibility of the startle stimulus after unilateral high-frequency noise exposure (16 kHz). However, rats still showed a 57% reduction in startle amplitude to the bandpass noise post-noise exposure. A follow-up experiment on a separate group of rats with transiently-induced conductive hearing loss revealed that startle reactivity was better preserved when the BBN startle stimulus was replaced by a rapid airpuff to the back of the rat's neck. Furthermore, it was found that transient unilateral conductive hearing loss, which was not likely to induce tinnitus, caused an impairment in gap prepulse

  20. Modality-specific attention under imminent but not remote threat of shock: evidence from differential prepulse inhibition of startle.

    PubMed

    Cornwell, Brian R; Echiverri, Aileen M; Covington, Matthew F; Grillon, Christian

    2008-06-01

    Theories of animal defensive behavior postulate that imminent, predictable threat elicits highly focused attention toward the threat source, whereas remote, unpredictable threat elicits distributed attention to the overall environment. We used threat of shock combined with measurement of prepulse inhibition of the startle reflex to test these claims in humans. Twenty-seven participants experienced periods of threat and safety. Threat and safe periods were short or long, with the short threat periods conveying relatively predictable, imminent shocks and the long threat periods conveying unpredictable shocks. Startle reflexes were elicited with equal numbers of acoustic probes presented alone, preceded by a tactile prepulse, or preceded by an auditory prepulse. We observed enhanced tactile relative to auditory prepulse inhibition during short threat periods only. This finding supports the notion that imminent threat, but not remote threat, elicits attention focused toward the relevant modality, potentially reflecting preparatory activity to minimize the impact of the noxious stimulus.

  1. The Effect of the 226-Hz Probe Level on Contralateral Acoustic Stapedius Reflex Thresholds

    ERIC Educational Resources Information Center

    Day, Jessica E.; Feeney, M. Patrick

    2008-01-01

    Purpose: The purpose of this study was to examine the effect of the 226-Hz probe level on the acoustic stapedius reflex threshold. Method: Contralateral reflex thresholds for a 1000-Hz pure-tone stimulus were obtained from 40 young adults with normal hearing using an experimental system at four 226-Hz probe levels (70, 75, 80, and 85 dB SPL) with…

  2. Effect of facial self-resemblance on the startle response and subjective ratings of erotic stimuli in heterosexual men.

    PubMed

    Lass-Hennemann, Johanna; Deuter, Christian E; Kuehl, Linn K; Schulz, Andre; Blumenthal, Terry D; Schachinger, Hartmut

    2011-10-01

    Cues of kinship are predicted to increase prosocial behavior due to the benefits of inclusive fitness, but to decrease approach motivation due to the potential costs of inbreeding. Previous studies have shown that facial resemblance, a putative cue of kinship, increases prosocial behavior. However, the effects of facial resemblance on mating preferences are equivocal, with some studies finding that facial resemblance decreases sexual attractiveness ratings, while other studies show that individuals choose mates partly on the basis of similarity. To further investigate this issue, a psychophysiological measure of affective processing, the startle response, was used in this study, assuming that differences in approach motivation to erotic pictures will modulate startle. Male volunteers (n = 30) viewed 30 pictures of erotic female nudes while startle eyeblink responses were elicited by acoustic noise probes. The female nude pictures were digitally altered so that the face either resembled the male participant or another participant, or were not altered. Non-nude neutral pictures were also included. Importantly, the digital alteration was undetected by the participants. Erotic pictures were rated as being pleasant and clearly reduced startle eyeblink magnitude as compared to neutral pictures. Participants showed greater startle inhibition to self-resembling than to other-resembling or non-manipulated female nude pictures, but subjective pleasure and arousal ratings did not differ among the three erotic picture categories. Our data suggest that visual facial resemblance of opposite-sex nudes increases approach motivation in men, and that this effect was not due to their conscious evaluation of the erotic stimuli.

  3. Involvement of pallidotegmental neurons in methamphetamine- and MK-801-induced impairment of prepulse inhibition of the acoustic startle reflex in mice: reversal by GABAB receptor agonist baclofen.

    PubMed

    Arai, Sawako; Takuma, Kazuhiro; Mizoguchi, Hiroyuki; Ibi, Daisuke; Nagai, Taku; Takahashi, Kenji; Kamei, Hiroyuki; Nabeshima, Toshitaka; Yamada, Kiyofumi

    2008-12-01

    We have previously demonstrated that pallidotegmental GABAergic neurons play a crucial role in prepulse inhibition (PPI) of the startle reflex in mice through the activation of GABA(B) receptors in pedunculopontine tegmental neurons. In this study, we investigated whether PPI disruption induced by methamphetamine (METH) or MK-801 is associated with the dysfunction of pallidotegmental neurons. Furthermore, we examined the effects of baclofen, a GABA(B) receptor agonist, on METH- and MK-801-induced PPI impairment. Acute treatment with METH (3 mg/kg, subcutaneouly (s.c.)) and MK-801 (>0.3 mg/kg, s.c.) significantly disrupted PPI, accompanied by the suppression of c-Fos expression in lateral globus pallidus induced by PPI. Furthermore, acute treatment with METH and MK-801 stimulated c-Fos expression in the caudal pontine reticular nucleus (PnC) in mice subjected to the PPT test, although PPI alone had no effect on c-Fos expression. Repeated treatment with 1 mg/kg METH for 7 days, which did not affect PPI acutely, showed similar effects on PPI and c-Fos expression to acute treatment with METH (3 mg/kg). Baclofen dose-dependently ameliorated PPI impairment induced by acute treatment with METH (3 mg/kg) and MK-801 (1 mg/kg), and decreased METH- and MK-801-stimulated c-Fos expression in PnC to the basal level. These results suggest that dysfunction of pallidotegmental neurons is involved in PPI disruption caused by METH and MK-801 in mice. GABA(B) receptor may constitute a putative target in treating neuropsychiatric disorders with sensorimotor gating deficits, such as schizophrenia and METH psychosis.

  4. Probing confined acoustic phonons in free standing small gold nanoparticles

    SciTech Connect

    Mankad, Venu; Jha, Prafulla K.; Ravindran, T. R.

    2013-02-21

    Polarized and depolarized spectra from gold (Au) nanoparticles of different sizes are investigated in the small size range, between 3 and 7 nm, using low frequency Raman spectroscopy. Acoustic vibrations of the free-standing Au nanoparticles are demonstrated with frequencies ranging from 5 to 35 cm{sup -1}, opening the way to the development of the acoustic resonators. A blue shift in the phonon peaks along with the broadening is observed with a decrease in particle size. Comparison of the measured frequencies with vibrational dynamics calculation and an examination as from the transmission electron microscopy results ascertain that the low frequency phonon modes are due to acoustic phonon quantization. Our results show that the observed low frequency Raman scattering originates from the spherical (l = 0) and quadrupolar (l = 2) vibrations of the spheroidal mode due to plasmon mediated acoustic vibrations in Au nanoparticles.

  5. Scanning probe acoustic microscopy of extruded starch materials: direct visual evidence of starch crystal.

    PubMed

    Liu, Zhongdong; Liu, Boxiang; Li, Mengxing; Wei, Min; Li, Hua; Liu, Peng; Wan, Tuo

    2013-10-15

    Scanning probe acoustic microscopy (SPAM) has been successfully used to study inorganic and keratin biomaterials. However, few studies have attempted to apply SPAM to structural study of non-keratin organic materials such as starch based materials. This study investigated hardness and surface finish to establish sample preparation method suitable for SPAM imaging and acquired clear acoustic images of extruded starch materials. Acquired acoustic images directly exhibited certain structure of starch materials and provided visual evidence of starch material components and aggregates. In addition, through correlating acoustic images with X-ray diffraction data, crystal-structural information in nano-scale was obtained and acoustic image contrast showed a linear relationship with starch amylose content in extruded starch materials.

  6. Optical probing of electric fields with an electro-acoustic effect toward integrated circuit diagnosis.

    PubMed

    Jin, Ru-Long; Yang, Han; Zhao, Di; Chen, Qi-Dai; Yan, Zhao-Xu; Yi, Mao-Bin; Sun, Hong-Bo

    2010-02-15

    Electro-optic probing of electric fields has been considered as a promising approach for integrated circuit diagnosis. However, the method is subject to relatively weak voltage sensitivity. In this Letter, we solve the problems with electro-acoustic effect. In contrast to the general electro-optic effect, the light phase modulation induced by the acoustic effect is 2 orders of magnitude stronger at its resonant frequency, as we observed in a GaAs thin film probe. Furthermore, this what we believe to be a novel method shows a highly reproducible linearity between the detected signals and the input voltages, which facilitates the voltage calibration.

  7. Simultaneous EMG-fMRI during startle inhibition in monosymptomatic enuresis--an exploratory study.

    PubMed

    Schulz-Juergensen, Sebastian; Wunberg, David; Wolff, Stephan; Eggert, Paul; Siniatchkin, Michael

    2013-01-01

    Evidence is growing that monosymptomatic enuresis (ME) is a maturational disorder of the central nervous system with a lack of arousal and lacking inhibition of the micturition reflex. Previous studies have shown a significant reduction of prepulse inhibition (PPI) of startle in children with enuresis. However, it is still unclear whether the abnormal PPI in enuresis is based on an inhibitory deficit at brainstem or cortical level. Nine children with ME and ten healthy children were investigated using simultaneous recording of EMG from the M. orbicularis oculi and functional MRI. The experimental paradigm consisted of acoustic startle stimulation, with startle-alone stimuli and prepulse-startle combinations. Functional MRI data were processed using multiple regression and parametric modulation with startle amplitudes as a parameter. Neither patients with enuresis nor healthy children revealed measurable PPI in the MRI scanner. Startle stimuli caused equal hemodynamic changes in the acoustic cortex, medial prefrontal and orbitofrontal cortex in both groups. The amplitude of startle correlated with more prominent BOLD signal changes in the anterior cingulate cortex in healthy subjects than in patients with ME. This pronounced frontal activation in healthy controls was related to the PPI condition, indicating that the prefrontal cortex of healthy children was activated more strongly to inhibit startle than in patients with ME. In conclusion, apart from the possibility that recordings of PPI inside the MRI scanner may be compromised by methodological problems, the results of this study suggest that high cortical control mechanisms at the prefrontal level are relevant for the pathogenesis of ME.

  8. Oxytocin reduces background anxiety in a fear-potentiated startle paradigm: peripheral vs central administration.

    PubMed

    Ayers, Luke W; Missig, Galen; Schulkin, Jay; Rosen, Jeffrey B

    2011-11-01

    Oxytocin is known to have anti-anxiety and anti-stress effects. Using a fear-potentiated startle paradigm in rats, we previously demonstrated that subcutaneously administered oxytocin suppressed acoustic startle following fear conditioning compared with startle before fear conditioning (termed background anxiety), but did not have an effect on cue-specific fear-potentiated startle. The findings suggest oxytocin reduces background anxiety, an anxious state not directly related to cue-specific fear, but sustained beyond the immediate threat. The goal of the present study was to compare the effects of centrally and peripherally administered oxytocin on background anxiety and cue-specific fear. Male rats were given oxytocin either subcutaneously (SC) or intracerebroventricularly (ICV) into the lateral ventricles before fear-potentiated startle testing. Oxytocin doses of 0.01 and 0.1 μg/kg SC reduced background anxiety. ICV administration of oxytocin at doses from 0.002 to 20 μg oxytocin had no effect on background anxiety or cue-specific fear-potentiated startle. The 20 μg ICV dose of oxytocin did reduce acoustic startle in non-fear conditioned rats. These studies indicate that oxytocin is potent and effective in reducing background anxiety when delivered peripherally, but not when delivered into the cerebroventricular system. Oxytocin given systemically may have anti-anxiety properties that are particularly germane to the hypervigilance and exaggerated startle typically seen in many anxiety and mental health disorder patients.

  9. Prenatal immune challenge in rats: altered responses to dopaminergic and glutamatergic agents, prepulse inhibition of acoustic startle, and reduced route-based learning as a function of maternal body weight gain after prenatal exposure to poly IC.

    PubMed

    Vorhees, Charles V; Graham, Devon L; Braun, Amanda A; Schaefer, Tori L; Skelton, Matthew R; Richtand, Neil M; Williams, Michael T

    2012-08-01

    Prenatal maternal immune activation has been used to test the neurodevelopmental hypothesis of schizophrenia. Most of the data are in mouse models; far less is available for rats. We previously showed that maternal weight change in response to the immune activator polyinosinic-polycytidylic acid (Poly IC) in rats differentially affects offspring. Therefore, we treated gravid Harlan Sprague-Dawley rats i.p. on embryonic day 14 with 8 mg/kg of Poly IC or Saline. The Poly IC group was divided into those that lost or gained the least weight, Poly IC (L), versus those that gained the most weight, Poly IC (H), following treatment. The study design controlled for litter size, litter sampling, sex distribution, and test experience. We found no effects of Poly IC on elevated zero maze, open-field activity, object burying, light-dark test, straight channel swimming, Morris water maze spatial acquisition, reversal, or shift navigation or spatial working or reference memory, or conditioned contextual or cued fear or latent inhibition. The Poly IC (H) group showed a significant decrease in the rate of route-based learning when visible cues were unavailable in the Cincinnati water maze and reduced prepulse inhibition of acoustic startle in females, but not males. The Poly IC (L) group exhibited altered responses to acute pharmacological challenges: exaggerated hyperactivity in response to (+)-amphetamine and an attenuated hyperactivity in response to MK-801. This model did not exhibit the cognitive, or latent inhibition deficits reported in Poly IC-treated rats but showed changes in response to drugs acting on neurotransmitter systems implicated in the pathophysiology of schizophrenia (dopaminergic hyperfunction and glutamatergic hypofunction).

  10. Multifrequency acoustics as a probe of mesoscopic blood coagulation dynamics

    NASA Astrophysics Data System (ADS)

    Ganesan, Adarsh; Rajendran, Gokulnath; Ercole, Ari; Seshia, Ashwin

    2016-08-01

    Coagulation is a complex enzymatic polymerisation cascade. Disordered coagulation is common in medicine and may be life-threatening yet clinical assays are typically bulky and/or provide an incomplete picture of clot mechanical evolution. We present the adaptation of an in-plane acoustic wave device: quartz crystal microbalance with dissipation at multiple harmonics to determine the time-evolution of mesoscale mechanical properties of clot formation in vitro. This approach is sensitive to changes in surface and bulk clot structure in various models of induced coagulopathy. Furthermore, we are able to show that clot formation at surfaces has different kinetics and mechanical strength to that in the bulk, which may have implications for the design of bioprosthetic materials. The "Multifrequency acoustics" approach thus enables unique capability to portray biological processes concerning blood coagulation.

  11. Presidential Address 2014: The more-or-less interrupting effects of the startle response.

    PubMed

    Blumenthal, Terry D

    2015-11-01

    The startle response can be used to assess differences in a variety of ongoing processes across species, sensory modalities, ages, clinical conditions, and task conditions. Startle serves defensive functions, but it may also interrupt ongoing processes, allowing for a reorientation of resources to potential danger. A wealth of research suggests that prepulse inhibition of startle (PPI) is an indicator of the protection of the processing of the prepulse from interruption by the startle response. However, protection against interruption by suppressing the startle response may extend to many other ongoing processes, including the higher processing of the startle stimulus itself. Proof of protection would require measuring ongoing processing, which has very rarely been reported. The idea that PPI represents the protection of the earliest stages of prepulse processing can be challenged, since those earliest stages are completed by the time the startle response occurs, so they are not threatened by interruption and need not be protected. The conception of low PPI as indicative of a "gating deficit" in schizophrenia should be made with caution, since low PPI is seen in some, but not all studies of schizophrenia, but also in a range of other disorders and conditions. Finally, startle is often used to probe ongoing processes, but the response also modifies those processes, interrupting some processes but perhaps facilitating others. A deeper understanding of the function of startle and PPI might improve the precision of application of these measures in the investigation of a range of research topics.

  12. Local probing of propagating acoustic waves in a gigahertz echo chamber

    NASA Astrophysics Data System (ADS)

    Gustafsson, Martin V.; Santos, Paulo V.; Johansson, Göran; Delsing, Per

    2012-04-01

    In the same way that micro-mechanical resonators resemble guitar strings and drums, surface acoustic waves resemble the sound these instruments produce, but moving over a solid surface rather than through air. In contrast with oscillations in suspended resonators, such propagating mechanical waves have not before been studied near the quantum mechanical limits. Here, we demonstrate local probing of surface acoustic waves with a displacement sensitivity of 30amRMSHz-1/2 and detection sensitivity on the single-phonon level after averaging, at a frequency of 932MHz. Our probe is a piezoelectrically coupled single-electron transistor, which is sufficiently fast, non-destructive and localized to enable us to track pulses echoing back and forth in a long acoustic cavity, self-interfering and ringing the cavity up and down. We project that strong coupling to quantum circuits will enable new experiments, and hybrids using the unique features of surface acoustic waves. Prospects include quantum investigations of phonon-phonon interactions, and acoustic coupling to superconducting qubits for which we present favourable estimates.

  13. Precise Wireless Triggering System for Anemometers with Long-Baseline Acoustic Probes

    NASA Astrophysics Data System (ADS)

    Wakatsuki, Naoto; Kinjo, Shin; Takarada, Jun; Mizutani, Koichi

    2010-07-01

    A wireless triggering system for acoustic anemometers using an acoustic probe with a long baseline is investigated. Acoustic probes for measuring micrometeorologic parameters, such as temperature and wind velocity, are used as noncontact and nondestructive methods. The acoustic probe with a long baseline was previously proposed by the authors and investigated to form a sensing grid system for micrometeorologic measurement. The authors have also partially investigated a wireless sensing grid using a wireless local-area network (LAN). However, because of the synchronization problem between sensor nodes, the trigger line has been left wired. In this paper, the problem of synchronization is solved by investigating a wireless triggering system using frequency modulated (FM) radio waves. The primitive triggering system of FM radio waves has some instability on time synchronization depending on such the communication environment as signal-to-noise ratio (SNR). To overcome the influence of the instability, a cross-correlation method is adopted to the triggering system. As a result, the time synchronization errors of the trigger system were reduced by up to one tenth. In addition, not only the instability problem but also other larger errors are compensated by the proposed system in an experimental wind velocity measurement.

  14. Probing Thermomechanics at the Nanoscale: Impulsively Excited Pseudosurface Acoustic Waves in Hypersonic Phononic Crystals

    PubMed Central

    2011-01-01

    High-frequency surface acoustic waves can be generated by ultrafast laser excitation of nanoscale patterned surfaces. Here we study this phenomenon in the hypersonic frequency limit. By modeling the thermomechanics from first-principles, we calculate the system’s initial heat-driven impulsive response and follow its time evolution. A scheme is introduced to quantitatively access frequencies and lifetimes of the composite system’s excited eigenmodes. A spectral decomposition of the calculated response on the eigemodes of the system reveals asymmetric resonances that result from the coupling between surface and bulk acoustic modes. This finding allows evaluation of impulsively excited pseudosurface acoustic wave frequencies and lifetimes and expands our understanding of the scattering of surface waves in mesoscale metamaterials. The model is successfully benchmarked against time-resolved optical diffraction measurements performed on one-dimensional and two-dimensional surface phononic crystals, probed using light at extreme ultraviolet and near-infrared wavelengths. PMID:21910426

  15. Fractionation of muscle activity in rapid responses to startling cues

    PubMed Central

    Dean, Lauren R.

    2017-01-01

    Movements in response to acoustically startling cues have shorter reaction times than those following less intense sounds; this is known as the StartReact effect. The neural underpinnings for StartReact are unclear. One possibility is that startling cues preferentially invoke the reticulospinal tract to convey motor commands to spinal motoneurons. Reticulospinal outputs are highly divergent, controlling large groups of muscles in synergistic patterns. By contrast the dominant pathway in primate voluntary movement is the corticospinal tract, which can access small groups of muscles selectively. We therefore hypothesized that StartReact responses would be less fractionated than standard voluntary reactions. Electromyogram recordings were made from 15 muscles in 10 healthy human subjects as they carried out 32 varied movements with the right forelimb in response to startling and nonstartling auditory cues. Movements were chosen to elicit a wide range of muscle activations. Multidimensional muscle activity patterns were calculated at delays from 0 to 100 ms after the onset of muscle activity and subjected to principal component analysis to assess fractionation. In all cases, a similar proportion of the total variance could be explained by a reduced number of principal components for the startling and the nonstartling cue. Muscle activity patterns for a given task were very similar in response to startling and nonstartling cues. This suggests that movements produced in the StartReact paradigm rely on similar contributions from different descending pathways as those following voluntary responses to nonstartling cues. NEW & NOTEWORTHY We demonstrate that the ability to activate muscles selectively is preserved during the very rapid reactions produced following a startling cue. This suggests that the contributions from different descending pathways are comparable between these rapid reactions and more typical voluntary movements. PMID:28003416

  16. Empirically based comparisons of the reliability and validity of common quantification approaches for eyeblink startle potentiation in humans.

    PubMed

    Bradford, Daniel E; Starr, Mark J; Shackman, Alexander J; Curtin, John J

    2015-12-01

    Startle potentiation is a well-validated translational measure of negative affect. Startle potentiation is widely used in clinical and affective science, and there are multiple approaches for its quantification. The three most commonly used approaches quantify startle potentiation as the increase in startle response from a neutral to threat condition based on (1) raw potentiation, (2) standardized potentiation, or (3) percent-change potentiation. These three quantification approaches may yield qualitatively different conclusions about effects of independent variables (IVs) on affect when within- or between-group differences exist for startle response in the neutral condition. Accordingly, we directly compared these quantification approaches in a shock-threat task using four IVs known to influence startle response in the no-threat condition: probe intensity, time (i.e., habituation), alcohol administration, and individual differences in general startle reactivity measured at baseline. We confirmed the expected effects of time, alcohol, and general startle reactivity on affect using self-reported fear/anxiety as a criterion. The percent-change approach displayed apparent artifact across all four IVs, which raises substantial concerns about its validity. Both raw and standardized potentiation approaches were stable across probe intensity and time, which supports their validity. However, only raw potentiation displayed effects that were consistent with a priori specifications and/or the self-report criterion for the effects of alcohol and general startle reactivity. Supplemental analyses of reliability and validity for each approach provided additional evidence in support of raw potentiation.

  17. Effects of a startle stimulus on response speed and inhibition in a go/no-go task.

    PubMed

    Washington, Jessica R; Blumenthal, Terry D

    2015-06-01

    Two studies examined the interaction of an acoustic startle stimulus and visual go/no-go task stimuli on startle reactivity and task performance. In the first study, an acoustic stimulus (50 ms, 100 dB noise) was presented alone or with a green (go) or red (no-go) circle; in the second study, a prepulse (50 ms, 75 dB noise) was presented alone or 120 ms before the startle stimulus or circle. The startle stimulus speeded responses to the go stimuli and increased the covert false alarm rate in the no-go condition (measured by EMG activity in the hand), although very few overt errors were made in the no-go condition. Startle response magnitude was increased by a circle but decreased by a prepulse. The speeding of go responses caused by a startle stimulus was attenuated by the occurrence of a startle response, suggesting that an intense accessory stimulus can facilitate responding to an imperative stimulus, and that the startle response to that intense stimulus can interfere with that facilitation.

  18. Effect of stress and attention on startle response and prepulse inhibition.

    PubMed

    De la Casa, Luis Gonzalo; Mena, Auxiliadora; Ruiz-Salas, Juan Carlos

    2016-10-15

    The startle reflex magnitude can be modulated when a weak stimulus is presented before the onset of the startle stimulus, a phenomenon termed prepulse inhibition (PPI). Previous research has demonstrated that emotional processes can modulate PPI and startle intensity, but the available evidence is inconclusive. In order to obtain additional evidence in this domain, we conducted two experiments intended to analyze the effect of induced stress and attentional load on PPI and startle magnitude. Specifically, in Experiment 1 we used a between subject strategy to evaluate the effect on startle response and PPI magnitude of performing a difficult task intended to induce stress in the participants, as compared to a group exposed to a control task. In Experiment 2 we evaluated the effect of diverting attention from the acoustic stimulus on startle and PPI intensity. The results seem to indicate that induced stress can reduce PPI, and that startle reflex intensity is reduced when attention is directed away from the auditory stimulus that induces the reflex.

  19. Acupuncture Affects Autonomic and Endocrine but Not Behavioural Responses Induced by Startle in Horses

    PubMed Central

    Villas-Boas, Julia Dias; Dias, Daniel Penteado Martins; Trigo, Pablo Ignacio; Almeida, Norma Aparecida dos Santos; de Almeida, Fernando Queiroz; de Medeiros, Magda Alves

    2015-01-01

    Startle is a fast response elicited by sudden acoustic, tactile, or visual stimuli in a variety of animals and in humans. As the magnitude of startle response can be modulated by external and internal variables, it can be a useful tool to study reaction to stress. Our study evaluated whether acupuncture can change cardiac autonomic modulation (heart rate variability); and behavioural (reactivity) and endocrine (cortisol levels) parameters in response to startle. Brazilian Sport horses (n = 6) were subjected to a model of startle in which an umbrella was abruptly opened near the horse. Before startle, the horses were subjected to a 20-minute session of acupuncture in acupoints GV1, HT7, GV20, and BL52 (ACUP) and in nonpoints (NP) or left undisturbed (CTL). For analysis of the heart rate variability, ultrashort-term (64 s) heart rate series were interpolated (4 Hz) and divided into 256-point segments and the spectra integrated into low (LF; 0.01–0.07 Hz; index of sympathetic modulation) and high (HF; 0.07–0.50 Hz; index of parasympathetic modulation) frequency bands. Acupuncture (ACUP) changed the sympathovagal balance with a shift towards parasympathetic modulation, reducing the prompt startle-induced increase in LF/HF and reducing cortisol levels 30 min after startle. However, acupuncture elicited no changes in behavioural parameters. PMID:26413116

  20. Two-Bubble Acoustic Tweezing Cytometry for Biomechanical Probing and Stimulation of Cells

    PubMed Central

    Chen, Di; Sun, Yubing; Gudur, Madhu S.R.; Hsiao, Yi-Sing; Wu, Ziqi; Fu, Jianping; Deng, Cheri X.

    2015-01-01

    The study of mechanotransduction relies on tools that are capable of applying mechanical forces to elicit and assess cellular responses. Here we report a new (to our knowledge) technique, called two-bubble acoustic tweezing cytometry (TB-ATC), for generating spatiotemporally controlled subcellular mechanical forces on live cells by acoustic actuation of paired microbubbles targeted to the cell adhesion receptor integrin. By measuring the ultrasound-induced activities of cell-bound microbubbles and the actin cytoskeleton contractile force responses, we determine that TB-ATC elicits mechanoresponsive cellular changes via cyclic, paired displacements of integrin-bound microbubbles driven by the attractive secondary acoustic radiation force (sARF) between the bubbles in an ultrasound field. We demonstrate the feasibility of dual-mode TB-ATC for both subcellular probing and mechanical stimulation. By exploiting the robust and unique interaction of ultrasound with microbubbles, TB-ATC provides distinct advantages for experimentation and quantification of applied forces and cellular responses for biomechanical probing and stimulation of cells. PMID:25564850

  1. Toward an understanding of the emotion-modulated startle eyeblink reflex: the case of anger.

    PubMed

    Peterson, Carly K; Harmon-Jones, Eddie

    2012-11-01

    Three studies investigated the effect of angering pictures on the startle eyeblink response, based on anger's unique identity as an approach-oriented negative affect. In Study 1, eyeblinks to startling noise probes during angering and neutral pictures did not differ, despite angering pictures being rated higher on arousal and anger and more negative in valence. Study 2 replicated Study 1; also, dysphoric participants exhibited potentiated eyeblinks to probes during angering pictures much like those to probes during fear/disgust stimuli. A follow-up study revealed that dysphoric participants rated angering pictures higher in fear. Study 3 again found that eyeblinks to probes during angering and neutral pictures did not differ. Taken together, these results suggest that probes during angering stimuli elicit eyeblinks much like those during neutral stimuli, perhaps due to the competing influences of arousal, valence, and motivation on the startle eyeblink reflex.

  2. Observations of liver cancer cells in scanning probe acoustic microscope: a preliminary study

    NASA Astrophysics Data System (ADS)

    Chen, Xiaohui; Fang, Xiaoyue; Xi, Qing; Guo, Hua; Zhang, Ning; Ding, Mingyue

    2016-04-01

    Scanning probe acoustic microscope (SPAM) can be used to acquire the morphology image as well as the non-destructive internal structures acoustic image. However, the observations of the morphology image as well as the internal structures acoustic image of liver cancer cells in SPAM are few. In this paper, we cultured 4 different types of liver cancer cells on the silicon wafer and coverslip to observe their morphology images as well as acoustic images in SPAM, and made a preliminary study of the 8 types of cells specimens (hereinafter referred to as the silicon specimens and coverslips specimens). The experimental measurement results showed that some cellular pseudopodium were observed in the morphology images of the coverslip specimens while no such cellular pseupodium were appeared in the morphology images of the silicon specimens, which concluded that the living liver cancer cells were less likely to grow on the silicon wafer. SPAM provides a rapid and sensitive visual method for studying the morphology and internal structures of the cancer cells. The proposed method can be also used to obtain the morphology and internal information in both solid and soft material wafers, such as silicon and cells, with the resolution of nanometer scale.

  3. Remote opto-acoustic probing of single-cell adhesion on metallic surfaces.

    PubMed

    Abi Ghanem, Maroun; Dehoux, Thomas; Zouani, Omar F; Gadalla, Atef; Durrieu, Marie-Christine; Audoin, Bertrand

    2014-06-01

    The reflection of picosecond ultrasonic pulses from a cell-substrate interface is used to probe cell-biomaterial adhesion with a subcell resolution. We culture monocytes on top of a thin biocompatible Ti metal film, supported by a transparent sapphire substrate. Low-energy femtosecond pump laser pulses are focused at the bottom of the Ti film to a micron spot. The subsequent ultrafast thermal expansion launches a longitudinal acoustic pulse in Ti, with a broad spectrum extending up to 100 GHz. We measure the acoustic echoes reflected from the Ti-cell interface through the transient optical reflectance changes. The time-frequency analysis of the reflected acoustic pulses gives access to a map of the cell acoustic impedance Zc and to a map of the film-cell interfacial stiffness K simultaneously. Variations in Zc across the cell are attributed to rigidity and density fluctuations within the cell, whereas variations in K are related to interfacial intermolecular forces and to the nano-architecture of the transmembrane bonds.

  4. Hydrocortisone Suppression of the Fear-potentiated Startle Response and Posttraumatic Stress Disorder

    PubMed Central

    Miller, Mark W.; McKinney, Ann E.; Kanter, Fredrick S.; Korte, Kristina J.; Lovallo, William R.

    2011-01-01

    This study examined the effects of oral administration of 20 mg hydrocortisone on baseline and fear-potentiated startle in 63 male veterans with or without PTSD. The procedure was based on a two-session, within-subject design in which acoustic startle eyeblink responses were recorded during intervals of threat or no threat of electric shock. Results showed that the magnitude of the difference between startle responses recorded during anticipation of imminent shock compared to “safe” periods was reduced after hydrocortisone administration relative to placebo. This effect did not vary as a function of PTSD group nor were there were any significant group differences in other indices startle amplitude. Findings suggest that the acute elevations in systemic cortisol produced by hydrocortisone administration may have fear-inhibiting effects. This finding may have implications for understanding the role of hypothalamic-pituitary-adrenal (HPA)-axis function in vulnerability and resilience to traumatic stress. PMID:21269779

  5. Monitoring Gold Nanoparticle Growth in Situ via the Acoustic Vibrations Probed by Four-Wave Mixing.

    PubMed

    Wu, Jian; Xiang, Dao; Gordon, Reuven

    2017-02-21

    We monitor in situ gold nanoparticle growth in aqueous solution by probing the acoustic vibrations with four-wave mixing. We observe two acoustic vibrational modes of gold nanoparticles from the nonlinear optical response: an extensional mode with longitudinal expansion and transverse contraction and a breathing mode with radial expansion and contraction. The mode frequencies, which show an inverse dependence on the nanoparticle diameter, allow one to monitor the nanoparticle size and size distribution during synthesis. The information about the nanoparticle size and size distribution calculated on the basis of the mode frequencies agrees well with the results obtained from the electron microscopy analysis, validating the four-wave mixing technique as an accurate and effective tool for in situ monitoring of colloidal growth.

  6. Probing the Raman-active acoustic vibrations of nanoparticles with extraordinary spectral resolution

    NASA Astrophysics Data System (ADS)

    Wheaton, Skyler; Gelfand, Ryan M.; Gordon, Reuven

    2015-01-01

    Colloidal quantum dots, viruses, DNA and all other nanoparticles have acoustic vibrations that can act as ‘fingerprints’ to identify their shape, size and mechanical properties, yet high-resolution Raman spectroscopy in this low-energy range has been lacking. Here, we demonstrate extraordinary acoustic Raman (EAR) spectroscopy to measure the Raman-active vibrations of single isolated nanoparticles in the 0.1-10 cm-1 range with ˜0.05 cm-1 resolution, to resolve peak splitting from material anisotropy and to probe the low-frequency modes of biomolecules. EAR employs a nanoaperture laser tweezer that can select particles of interest and manipulate them once identified. We therefore believe that this nanotechnology will enable expanded capabilities for the study of nanoparticles in the materials and life sciences.

  7. Calibration and Sediment Load Algorithms for an Acoustic Sediment Flux Probe

    DTIC Science & Technology

    1994-06-01

    15867+591 16421-237 146984177 16475.218 F*=t 4.1 shows the plot of dhe valum of thed sme vies, cuaed uing Eqaton (4.1) md I -pt mkn for M=ntr Whar for...allow a satisfactomy estimation of the mean parficle radius of the lognoaial sediment population over a range fhn 20 tD 100 mimm wuig the two-frequncy...Cylinders: Thin-wire Slnd• Td 7Jownal Aw A m= , 94(5), November 13. Stuima T. P., Th Coherent Acoustic Sediment Flux Probe (CASP), submitted to U. S

  8. Acoustic Attenuation Probe for Fermion Superfluidity in Ultracold-Atom Gases

    SciTech Connect

    Gaudio, Sergio; Mihaila, Bogdan; Blagoev, Krastan B.; Timmermans, Eddy; Bedell, Kevin S.

    2007-03-16

    Dilute gas Bose-Einstein condensates (BEC's), currently used to cool fermionic atoms in atom traps, can also probe the superfluidity of these fermions. The damping rate of BEC-acoustic excitations (phonon modes), measured in the middle of the trap as a function of the phonon momentum, yields an unambiguous signature of BCS-like superfluidity, provides a measurement of the superfluid gap parameter, and gives an estimate of the size of the Cooper pairs in the BEC-BCS crossover regime. We also predict kinks in the momentum dependence of the damping rate which can reveal detailed information about the fermion quasiparticle dispersion relation.

  9. Argon–oxygen dc magnetron discharge plasma probed with ion acoustic waves

    SciTech Connect

    Saikia, Partha Saikia, Bipul Kumar; Goswami, Kalyan Sindhu; Phukan, Arindam

    2014-05-15

    The precise determination of the relative concentration of negative ions is very important for the optimization of magnetron sputtering processes, especially for those undertaken in a multicomponent background produced by adding electronegative gases, such as oxygen, to the discharge. The temporal behavior of an ion acoustic wave excited from a stainless steel grid inside the plasma chamber is used to determine the relative negative ion concentration in the magnetron discharge plasma. The phase velocity of the ion acoustic wave in the presence of negative ions is found to be faster than in a pure argon plasma, and the phase velocity increases with the oxygen partial pressure. Optical emission spectroscopy further confirms the increase in the oxygen negative ion density, along with a decrease in the argon positive ion density under the same discharge conditions. The relative negative ion concentration values measured by ion acoustic waves are compared with those measured by a single Langmuir probe, and a similarity in the results obtained by both techniques is observed.

  10. Behavioral and pharmacological validation of an integrated fear-potentiated startle and prepulse inhibition paradigm.

    PubMed

    Zhang, Mengjiao; Li, Ming

    2016-07-01

    Fear-potentiated startle (FPS) and prepulse inhibition (PPI) of acoustic startle are two widely used paradigms specifically designed to capture the impact of negative emotion (e.g. fear) and preattentive function on startle response. Currently, there is no single paradigm that incorporates both FPS and PPI, making it impossible to examine the potential interactions between fear and attention in the regulation of startle response. In this study, we developed an integrated FPS and PPI test protocol and validated it with psychoactive drugs. In Experiment 1, male Sprague-Dawley rats were randomly assigned to one of five groups, receiving either Light -Shock conditioning trials, non-overlapping Lights and Shocks, Light alone, Shock alone, or no Light and Shock. They were then tested for startle response and PPI concurrently, under the Light or No Light. FPS was observed only in rats subjected to fear conditioning, whereas all rats showed PPI and startle habituation. Experiment 2 used this paradigm and demonstrated a dissociative effect between diazepam (an anxiolytic drug) and phencyclidine (a nonselective NMDA receptor antagonist) on FPS and PPI. Diazepam suppressed both FPS and PPI, while PCP selectively disrupted PPI but not FPS. The diazepam's anxiolytic effect on FPS was further confirmed in the elevated plus maze test. Together, our findings indicate that our paradigm combines FPS and PPI into a single paradigm, and that is useful to examine potential interactions between multiple psychological processes, to identify the common neural substrates and to screen new drugs with multiple psychoactive effects.

  11. Between Site Reliability of Startle Prepulse Inhibition Across Two Early Psychosis Consortia

    PubMed Central

    Addington, Jean; Cannon, Tyrone D.; Cornblatt, Barbara A.; de la Fuente-Sandoval, Camilo; Mathalon, Dan H.; Perkins, Diana O.; Seidman, Larry J.; Tsuang, Ming; Walker, Elaine F.; Woods, Scott W.; Bachman, Peter; Belger, Ayse; Carrión, Ricardo E.; Donkers, Franc C.L.; Duncan, Erica; Johannesen, Jason; León-Ortiz, Pablo; Light, Gregory; Mondragón, Alejandra; Niznikiewicz, Margaret; Nunag, Jason; Roach, Brian J.; Solís-Vivanco, Rodolfo

    2014-01-01

    Prepulse inhibition (PPI) and reactivity of the acoustic startle response are widely used biobehavioral markers in psychopathology research. Previous studies have demonstrated that PPI and startle reactivity exhibit substantial within-site stability; between-site stability, however, has not been established. In two separate consortia investigating biomarkers of early psychosis, traveling subjects studies were performed as part of quality assurance procedures in order to assess the fidelity of data across sites. In the North American Prodromal Longitudinal Studies (NAPLS) Consortium, 8 normal subjects traveled to each of the 8 NAPLS sites and were tested twice at each site on the startle PPI paradigm. In preparation for a binational study, 10 healthy subjects were assessed twice in both San Diego and Mexico City. Intraclass correlations between and within sites were significant for PPI and startle response parameters, confirming the reliability of startle measures across sites in both consortia. There were between site differences in startle magnitude in the NAPLS study that did not appear to be related to methods or equipment. In planning multi-site studies, it is essential to institute quality assurance procedures early and establish between site reliability to assure comparable data across sites. PMID:23799460

  12. Direct gaze of photographs of female nudes influences startle in men.

    PubMed

    Lass-Hennemann, Johanna; Schulz, André; Nees, Frauke; Blumenthal, Terry D; Schachinger, Hartmut

    2009-05-01

    Foreground presentation of photographs of opposite sex nudes lowers startle elicited by sudden acoustic stimuli. However, the impact of gaze direction of the presented nudes on this startle modulation has not been investigated. Theoretically, direct gaze of photographs of female nudes could either lead to a larger inhibition of the startle reaction due to a summating valence and arousal effect of direct eye contact, or lead to a smaller inhibition due to an attention capturing effect of the eyes. Two subsets of erotic photographs of female nudes (women looking directly at the observer vs. gazing away) and standard IAPS neutral pictures were viewed by 26 male volunteers, while startle eye blink responses to binaural bursts of white noise (50 ms, 105 dB) were recorded by EMG. Erotic pictures reduced startle eyeblink magnitude as compared to neutral pictures. Furthermore, erotic stimuli without direct gaze at the observer showed a greater startle eyeblink inhibition than erotic stimuli with direct gaze at the observer. Our data suggest that direct gaze of opposite sex nudes may direct attention to the face, thereby reducing the appetitive impact of an attractive body.

  13. Affective Influences on Startle in Five-Month-Old Infants: Reactions to Facial Expressions of Emotion.

    ERIC Educational Resources Information Center

    Balaban, Marie T.

    1995-01-01

    While 18 5-month-old infants viewed photographic slides of faces posed in happy, neutral, or angry expressions, a brief acoustic noise burst was presented to elicit the blink component of human startle. It was found that blink size was augmented during the viewing of angry expressions and reduced during viewing of happy expressions. (MDM)

  14. Deficits in startle-evoked arm movements increase with impairment following stroke

    PubMed Central

    Honeycutt, Claire Fletcher; Perreault, Eric Jon

    2014-01-01

    Objective The startle reflex elicits involuntary release of planned movements (startReact). Following stroke, startReact flexion movements are intact but startReact extension movements are impaired by task-inappropriate flexor activity impeding arm extension. Our objective was to quantify deficits in startReact elbow extension movements, particularly how these deficits are influenced by impairment. Methods Data were collected in 8 stroke survivors performing elbow extension following two non-startling acoustic stimuli representing “get ready” and “go” respectively. Randomly, the “go” was replaced with a startling acoustic stimulus. We hypothesized that task-inappropriate flexor activity originates from unsuppressed classic startle reflex. We expected that increasing damage to the cortex (increasing impairment) would relate to increasing task-inappropriate flexor activity causing poor elbow extension movement and target acquisition. Results Task-inappropriate flexor activity increased with impairment resulting in larger flexion deflections away from the subjects’ intended target corresponding to decreased target acquisition. Conclusions We conclude that the task-inappropriate flexor activity likely results from cortical or corticospinal damage leading to an unsuppressed or hypermetric classic startle reflex that interrupts startReact elbow extension. Significance Given startReact’s functional role in compensation during environmental disturbances, our results may have important implications for our understanding deficits in stroke survivor’s response to unexpected environmental disturbances. PMID:24411525

  15. Frequency Response of the Sample Vibration Mode in Scanning Probe Acoustic Microscope

    NASA Astrophysics Data System (ADS)

    Zhao, Ya-Jun; Cheng, Qian; Qian, Meng-Lu

    2010-05-01

    Based on the interaction mechanism between tip and sample in the contact mode of a scanning probe acoustic microscope (SPAM), an active mass of the sample is introduced in the mass-spring model. The tip motion and frequency response of the sample vibration mode in the SPAM are calculated by the Lagrange equation with dissipation function. For the silicon tip and glass assemblage in the SPAM the frequency response is simulated and it is in agreement with the experimental result. The living myoblast cells on the glass slide are imaged at resonance frequencies of the SPAM system, which are 20kHz, 30kHz and 120kHz. It is shown that good contrast of SPAM images could be obtained when the system is operated at the resonance frequencies of the system in high and low-frequency regions.

  16. Remote vibration measurement: A wireless passive surface acoustic wave resonator fast probing strategy

    NASA Astrophysics Data System (ADS)

    Friedt, J.-M.; Droit, C.; Ballandras, S.; Alzuaga, S.; Martin, G.; Sandoz, P.

    2012-05-01

    Surface acoustic wave (SAW) resonators can advantageously operate as passive sensors which can be interrogated through a wireless link. Amongst the practical applications of such devices, structural health monitoring through stress measurement and more generally vibration characteristics of mechanical structures benefit from the ability to bury such sensors within the considered structure (wireless and battery-less). However, measurement bandwidth becomes a significant challenge when measuring wideband vibration characteristics of mechanical structures. A fast SAW resonator measurement scheme is demonstrated here. The measurement bandwidth is limited by the physical settling time of the resonator (Q/π periods), requiring only two probe pulses through a monostatic RADAR-like electronic setup to identify the sensor resonance frequency and hence stress on a resonator acting as a strain gauge. A measurement update rate of 4800 Hz using a high quality factor SAW resonator operating in the 434 MHz Industrial, Scientific and Medical band is experimentally demonstrated.

  17. Remote vibration measurement: a wireless passive surface acoustic wave resonator fast probing strategy.

    PubMed

    Friedt, J-M; Droit, C; Ballandras, S; Alzuaga, S; Martin, G; Sandoz, P

    2012-05-01

    Surface acoustic wave (SAW) resonators can advantageously operate as passive sensors which can be interrogated through a wireless link. Amongst the practical applications of such devices, structural health monitoring through stress measurement and more generally vibration characteristics of mechanical structures benefit from the ability to bury such sensors within the considered structure (wireless and battery-less). However, measurement bandwidth becomes a significant challenge when measuring wideband vibration characteristics of mechanical structures. A fast SAW resonator measurement scheme is demonstrated here. The measurement bandwidth is limited by the physical settling time of the resonator (Q/π periods), requiring only two probe pulses through a monostatic RADAR-like electronic setup to identify the sensor resonance frequency and hence stress on a resonator acting as a strain gauge. A measurement update rate of 4800 Hz using a high quality factor SAW resonator operating in the 434 MHz Industrial, Scientific and Medical band is experimentally demonstrated.

  18. Mechanical Properties of Silicone Rubber Acoustic Lens Material Doped with Fine Zinc Oxide Powders for Ultrasonic Medical Probe

    NASA Astrophysics Data System (ADS)

    Yamamoto, Noriko; Yohachi; Yamashita; Itsumi, Kazuhiro

    2009-07-01

    The mechanical properties of high-temperature-vulcanization silicone (Q) rubber doped with zinc oxide (ZnO) fine powders have been investigated to develop an acoustic lens material with high reliability. The ZnO-doped Q rubber with an acoustic impedance (Z) of 1.46×106 kg·m-2·s-1 showed a tear strength of 43 N/mm and an elongation of 560%. These mechanical property values were about 3 times higher than those of conventional acoustic Q lens materials. The ZnO-doped Q rubbers also showed a lower abrasion loss. These superior characteristics are attributable to the microstructure with fewer origins of breaks; few pores and spherical fine ZnO powder. The high mechanical properties of ZnO-doped Q rubber acoustic lenses enable higher performance during long-life and safe operation during diagnosis using medical array probe applications.

  19. Fear-potentiated startle processing in humans: Parallel fMRI and orbicularis EMG assessment during cue conditioning and extinction.

    PubMed

    Lindner, Katja; Neubert, Jörg; Pfannmöller, Jörg; Lotze, Martin; Hamm, Alfons O; Wendt, Julia

    2015-12-01

    Studying neural networks and behavioral indices such as potentiated startle responses during fear conditioning has a long tradition in both animal and human research. However, most of the studies in humans do not link startle potentiation and neural activity during fear acquisition and extinction. Therefore, we examined startle blink responses measured with electromyography (EMG) and brain activity measured with functional MRI simultaneously during differential conditioning. Furthermore, we combined these behavioral fear indices with brain network activity by analyzing the brain activity evoked by the startle probe stimulus presented during conditioned visual threat and safety cues as well as in the absence of visual stimulation. In line with previous research, we found a fear-induced potentiation of the startle blink responses when elicited during a conditioned threat stimulus and a rapid decline of amygdala activity after an initial differentiation of threat and safety cues in early acquisition trials. Increased activation during processing of threat cues was also found in the anterior insula, the anterior cingulate cortex (ACC), and the periaqueductal gray (PAG). More importantly, our results depict an increase of brain activity to probes presented during threatening in comparison to safety cues indicating an involvement of the anterior insula, the ACC, the thalamus, and the PAG in fear-potentiated startle processing during early extinction trials. Our study underlines that parallel assessment of fear-potentiated startle in fMRI paradigms can provide a helpful method to investigate common and distinct processing pathways in humans and animals and, thus, contributes to translational research.

  20. Self-Characterization of Commercial Ultrasound Probes in Transmission Acoustic Inverse Scattering: Transducer Model and Volume Integral Formulation

    PubMed Central

    Haynes, Mark; Verweij, Sacha A. M.; Moghaddam, Mahta; Carson, Paul L.

    2014-01-01

    A self-contained source characterization method for commercial ultrasound probes in transmission acoustic inverse scattering is derived and experimentally tested. The method is based on modified scattered field volume integral equations that are linked to the source-scattering transducer model. The source-scattering parameters are estimated via pair-wise transducer measurements and the nonlinear inversion of an acoustic propagation model that is derived. This combination creates a formal link between the transducer characterization and the inverse scattering algorithm. The method is tested with two commercial ultrasound probes in a transmission geometry including provisions for estimating the probe locations and aligning a robotic rotator. The transducer characterization results show that the nonlinear inversion fit the measured data well. The transducer calibration and inverse scattering algorithm are tested on simple targets. Initial images show that the recovered contrasts are physically consistent with expected values. PMID:24569251

  1. The CRH1 antagonist GSK561679 increases human fear but not anxiety as assessed by startle.

    PubMed

    Grillon, Christian; Hale, Elizabeth; Lieberman, Lynne; Davis, Andrew; Pine, Daniel S; Ernst, Monique

    2015-03-13

    Fear to predictable threat and anxiety to unpredictable threat reflect distinct processes mediated by different brain structures, the central nucleus of the amygdala and the bed nucleus of the stria terminalis (BNST), respectively. This study tested the hypothesis that the corticotropin-releasing factor (CRF1) antagonist GSK561679 differentially reduces anxiety but increases fear in humans. A total of 31 healthy females received each of four treatments: placebo, 50 mg GSK561679 (low-GSK), 400 mg GSK561679 (high-GSK), and 1 mg alprazolam in a crossover design. Participants were exposed to three conditions during each of the four treatments. The three conditions included one in which predictable aversive shocks were signaled by a cue, a second during which shocks were administered unpredictably, and a third condition without shock. Fear and anxiety were assessed using the acoustic startle reflex. High-GSK had no effect on startle potentiation during unpredictable threat (anxiety) but increased startle potentiation during the predictable condition (fear). Low-GSK did not affect startle potentiation across conditions. Consistent with previous findings, alprazolam reduced startle potentiation during unpredictable threat but not during predictable threat. The increased fear by high-GSK replicates animal findings and suggests a lift of the inhibitory effect of the BNST on the amygdala by the CRF1 antagonist.

  2. Acoustic probe for the characterization of solid-gas- liquid slurries

    NASA Astrophysics Data System (ADS)

    Norato, Michael Anthony

    1999-10-01

    The development of nuclear weapons technology during the Cold War Era has left a legacy of large quantities of radioactive waste which are stored throughout the US Department of Energy (US DOE) Nuclear Weapons Complex. During the proposed remediation stages of processing, it will be necessary to characterize and monitor these waste slurries by remote methods. Acoustic probes have shown promise because of their non- intrusive nature and ability to penetrate optically opaque slurries. A forward theory for the acoustic response in both dilute and concentrated solid liquid slurries is developed. It is based on ensemble averaging of the equations of motion in the solid and liquid phases to obtain expressions for the ``effective properties'' of the slurry mixture in terms of coefficients which appear in the equations of motion for the solid particle. The attenuations predicted from the theory are in generally good agreement with the experimental data obtained by Toneburst and Pulse/FFT data acquisition methods for solid-liquid slurries of soda-lime glass particles of 14.9 μm and 65 μm mean radius and polystyrene particles of 79 gm radius at concentrations ranging from 5% to 50% solids by volume. The forward theory is readily extended to systems containing more than one dispersed phase, such as particles and gas bubbles, and the theory predictions are observed to be in good agreement with preliminary attenuation data obtained in solid-gas-liquid slurries of soda-lime glass particles of 14.9 gm mean radius at 5% and 10% by volume and gas bubbles ranging from approximately 25 μm to 150 μm radius at volume fractions on the order of 10-5. An inverse theory is also developed to determine the concentration and solids volume fraction distribution in a solid-liquid slurry given its experimentally obtained acoustic response. A Tikhonov scheme is employed to regularize the ill-posed integro-differential equations and solve them as a linear programming problem. Solution of the

  3. Acoustic probe for solid-gas-liquid suspensions. 1997 annual progress report

    SciTech Connect

    Tavlarides, L.L.; Sangani, A.S.

    1997-01-01

    'Acoustic probes have shown promise to be quite effective in determining the solid content in solid-liquid suspensions. However, the presence of small amounts of gas in the waste slurries stored in tanks across the DOE complex prevents straightforward application for characterization of these slurries. The proposed research will develop an acoustic probe for monitoring particle size and volume fraction in slurries in the absence and the presence of gas bubbles. Theoretical Analysis Accomplished: Attenuation of sound waves depends on the size distribution of the solids and the volume fraction of solids. These can in principle be calculated from attenuation measured over a range of frequencies. However, small amounts of bubbles distort the measured attenuation. A typical result from theoretical analysis for the attenuation of solid- gas-liquid systems is given in Figure 1. The total attenuation of a sound wave v(o) equals the sum of contributions by a large number of ''bins'' of particle sizes. This notion yields the following equation for the (hitherto) unknown number density of solid particles as a function of particle radius N(a): j k(o,a)N(a)da = v(o), where the kernel k(o,a) is obtained from analysis. If N(a) is given, the above equation is used to calculate the attenuation v(o). This is referred to as solving the ''forward problem''. Solving for N(a) with v(o) given is the ''inverse problem''. A complication that one faces when trying to solve the inverse problem is that the stated problem is mathematically ill-posed, i.e., small fluctuations in v(o) cause large fluctuations in the result for the number density. Therefore the problem needs to be ''regularized'', i.e., the stated problem needs to be changed slightly such as to make it well-posed. This has been done by others for gas-liquid systems in the past. This approach is currently being applied in the present project to solid-liquid systems. As is shown in Figure 2, it successfully recovers the number

  4. Laser-Doppler acoustic probing of granular media with in-depth property gradient and varying pore pressures

    SciTech Connect

    Bodet, L.; Dhemaied, A.; Mourgues, R.; Tournat, V.; Rejiba, F.

    2012-05-24

    Non-contacting ultrasonic techniques recently proved to be efficient in the physical modeling of seismic-wave propagation at various application scales, as for instance in the context of geological analogue and seismic modeling. An innovative experimental set-up is proposed here to perform laser-Doppler acoustic probing of unconsolidated granular media with varying pore pressures. The preliminary experiments presented here provide reproducible results and exploitable data, thus validating both the proposed medium preparation and pressure gradient generation procedure.

  5. Affective reactions to acoustic stimuli.

    PubMed

    Bradley, M M; Lang, P J

    2000-03-01

    Emotional reactions to naturally occurring sounds (e.g., screams, erotica, bombs, etc.) were investigated in two studies. In Experiment 1, subjects rated the pleasure and arousal elicited when listening to each of 60 sounds, followed by an incidental free recall task. The shape of the two-dimensional affective space defined by the mean ratings for each sound was similar to that previously obtained for pictures, and, like memory for pictures, free recall was highest for emotionally arousing stimuli. In Experiment 2, autonomic and facial electromyographic (EMG) activity were recorded while a new group of subjects listened to the same set of sounds; the startle reflex was measured using visual probes. Listening to unpleasant sounds resulted in larger startle reflexes, more corrugator EMG activity, and larger heart rate deceleration compared with listening to pleasant sounds. Electrodermal reactions were larger for emotionally arousing than for neutral materials. Taken together, the data suggest that acoustic cues activate the appetitive and defensive motivational circuits underlying emotional expression in ways similar to pictures.

  6. Child Maltreatment, Callous-Unemotional Traits, and Defensive Responding In High-Risk Children: An Investigation of Emotion-Modulated Startle Response

    PubMed Central

    Dackis, Melissa N.; Rogosch, Fred A.; Cicchetti, Dante

    2015-01-01

    Child maltreatment is associated with disruptions in physiological arousal, emotion regulation, and defensive responses to cues of threat and distress, as well as increased risk for callous unemotional (CU) traits and externalizing behavior. Developmental models of callous unemotional (CU) traits have focused on biological and genetic risk factors that contribute to hypoarousal and antisocial behavior, but have focused less on environmental influences (Blair, 2004; Daversa, 2010; Hare, Frazell, & Cox, 1978; Krueger, 2000; Shirtcliff et al., 2009; Viding, Fontaine, & McCrory, 2012). The aim of the present investigation was to measure the independent and combined effects of child maltreatment and high CU trait on emotion-modulated startle (EMS) response in children. Participants consisted of 132 low-income maltreated (n = 60) and nonmaltreated (n = 72) children between 8–12 years old who attended a summer camp program. Acoustic startle response (ASR) was elicited in response to a 110-dB 50-ms probe while children viewed a slideshow of pleasant, neutral, and unpleasant IAPS images. Maltreatment status was assessed through examination of Department of Human Services records. CU traits were measured using counselor reports from the Inventory of Callous and Unemotional Traits (ICU; Frick, 2004), and conduct problems were measured using counselor and child self-report. We found no significant differences in emotion-modulated startle in the overall sample. However, significant differences in ASR by maltreatment status, maltreatment subtype, and level of CU traits were apparent. Results indicated differential physiological responses for maltreated and nonmaltreated children based on CU traits, including a pathway of hypoarousal for nonmaltreated/high CU children that differed markedly from a more normative physiological trajectory for maltreated/high CU children. Further, we found heightened ASR for emotionally and physically neglected children with high CU and elevated

  7. Child maltreatment, callous-unemotional traits, and defensive responding in high-risk children: An investigation of emotion-modulated startle response.

    PubMed

    Dackis, Melissa N; Rogosch, Fred A; Cicchetti, Dante

    2015-11-01

    Child maltreatment is associated with disruptions in physiological arousal, emotion regulation, and defensive responses to cues of threat and distress, as well as increased risk for callous unemotional (CU) traits and externalizing behavior. Developmental models of CU traits have focused on biological and genetic risk factors that contribute to hypoarousal and antisocial behavior, but have focused less on environmental influences (Blair, 2004; Daversa, 2010; Hare, Frazell, & Cox, 1978; Krueger, 2000; Shirtcliff et al., 2009; Viding, Fontaine, & McCrory, 2012). The aim of the present investigation was to measure the independent and combined effects of child maltreatment and high CU traits on emotion-modulated startle response in children. Participants consisted of 132 low-income maltreated (n = 60) and nonmaltreated (n = 72) children between 8 and 12 years old who attended a summer camp program. Acoustic startle response (ASR) was elicited in response to a 110-dB 50-ms probe while children viewed a slideshow of pleasant, neutral, and unpleasant IAPS images. Maltreatment status was assessed through examination of Department of Human Services records. CU traits were measured using counselor reports from the Inventory of Callous and Unemotional Traits (Frick, 2004), and conduct problems were measured using counselor and child self-report. We found no significant differences in emotion-modulated startle in the overall sample. However, significant differences in ASR by maltreatment status, maltreatment subtype, and level of CU traits were apparent. Results indicated differential physiological responses for maltreated and nonmaltreated children based on CU traits, including a pathway of hypoarousal for nonmaltreated/high CU children that differed markedly from a more normative physiological trajectory for maltreated/high CU children. Further, we found heightened ASR for emotionally and physically neglected children with high CU and elevated antisocial behavior in these

  8. Prepulse inhibition and facilitation of the postauricular reflex, a vestigial remnant of pinna startle.

    PubMed

    Hackley, Steven A; Ren, Xi; Underwood, Amy; Valle-Inclán, Fernando

    2017-04-01

    If the postauricular reflex (PAR) is to be used effectively in studies of emotion and attention, its sensitivity to basic modulatory effects such as prepulse inhibition and facilitation must be determined. Two experiments were carried out with healthy young adults to assess the effects of transient and sustained visual prestimuli on the pinna-flexion response to trains of startle probes. In the first experiment, participants passively viewed a small white square. It was displayed from 1,000 ms prior to onset of a train of noise bursts until the end of that train. Relative to no-prepulse control trials, PAR amplitude was inhibited, possibly due to the withdrawal of attentional resources from the auditory modality. In the second experiment, participants performed a visual oddball task in which irrelevant trains of startle probes followed most briefly displayed task stimuli (checkerboards). Prepulse inhibition was observed when a transient stimulus preceded the first probe at a lead time of 100 ms. Amplitude facilitation was observed at longer lead times. In addition to documenting the existence of prepulse inhibition and facilitation, the data suggest that the PAR is not elicited by visual stimuli, that temporal expectancy does not influence its amplitude or latency, and that this vestigial microreflex is resistant to habituation. Results are interpreted in light of a recent theory that the human PAR is a highly degraded pinna startle, in which the reflex arc no longer includes the startle center (nucleus reticularis pontis caudalis).

  9. Peritraumatic startle response predicts the vulnerability to develop PTSD-like behaviors in rats: a model for peritraumatic dissociation.

    PubMed

    Dong, Xinwen; Li, Yonghui

    2014-01-01

    Peritraumatic dissociation, a state characterized by alteration in perception and reduced awareness of surroundings, is considered to be a risk factor for the development of post-traumatic stress disorder (PTSD). However, the predictive ability of peritraumatic dissociation is questioned for the inconsistent results in different time points of assessment. The startle reflex is an objective behavioral measurement of defensive response to abrupt and intense sensory stimulus of surroundings, with potential to be used as an assessment on the dissociative status in both humans and rodents. The present study examined the predictive effect of acoustic startle response (ASR) in different time points around the traumatic event in an animal model of PTSD. The PTSD-like symptoms, including hyperarousal, avoidance, and contextual fear, were assessed 2-3 weeks post-trauma. The results showed that (1) the startle amplitude attenuated immediate after intense footshock in almost half of the stress animals, and (2) the attenuated startle responses at 1 h but not 24 h after stress predicted the development of severe PTSD-like symptoms. These data indicate that the startle alteration at the immediate period after trauma, including 1 h, is more important in PTSD prediction than 24 h after trauma. Our study also suggests that the startle attenuation immediate after intense stress may serve as an objective measurement of peritraumatic dissociation in rats.

  10. Startle disease in Irish wolfhounds associated with a microdeletion in the glycine transporter GlyT2 gene

    PubMed Central

    Gill, Jennifer L.; Capper, Deborah; Vanbellinghen, Jean-François; Chung, Seo-Kyung; Higgins, Robert J.; Rees, Mark I.; Shelton, G. Diane; Harvey, Robert J.

    2011-01-01

    Defects in glycinergic synaptic transmission in humans, cattle, and rodents result in an exaggerated startle reflex and hypertonia in response to either acoustic or tactile stimuli. Molecular genetic studies have determined that mutations in the genes encoding the postsynaptic glycine receptor (GlyR) α1 and β subunits (GLRA1 and GLRB) and the presynaptic glycine transporter GlyT2 (SLC6A5) are the major cause of these disorders. Here, we report the first genetically confirmed canine cases of startle disease. A litter of seven Irish wolfhounds was identified in which two puppies developed muscle stiffness and tremor in response to handling. Although sequencing of GLRA1 and GLRB did not reveal any pathogenic mutations, analysis of SLC6A5 revealed a homozygous 4.2 kb microdeletion encompassing exons 2 and 3 in both affected animals. This results in the loss of part of the large cytoplasmic N-terminus and all subsequent transmembrane domains due to a frameshift. This genetic lesion was confirmed by defining the deletion breakpoint, Southern blotting, and multiplex ligation-dependent probe amplification (MLPA). This analysis enabled the development of a rapid genotyping test that revealed heterozygosity for the deletion in the dam and sire and three other siblings, confirming recessive inheritance. Wider testing of related animals has identified a total of 13 carriers of the SLC6A5 deletion as well as non-carrier animals. These findings will inform future breeding strategies and enable a rational pharmacotherapy of this new canine disorder. PMID:21420493

  11. Impaired conditioned fear response and startle reactivity in epinephrine-deficient mice.

    PubMed

    Toth, Mate; Ziegler, Michael; Sun, Ping; Gresack, Jodi; Risbrough, Victoria

    2013-02-01

    Norepinephrine and epinephrine signaling is thought to facilitate cognitive processes related to emotional events and heightened arousal; however, the specific role of epinephrine in these processes is less known. To investigate the selective impact of epinephrine on arousal and fear-related memory retrieval, mice unable to synthesize epinephrine (phenylethanolamine N-methyltransferase knockout, PNMT-KO) were tested for contextual and cued-fear conditioning. To assess the role of epinephrine in other cognitive and arousal-based behaviors these mice were also tested for acoustic startle, prepulse inhibition, novel object recognition, and open-field activity. Our results show that compared with wild-type mice, PNMT-KO mice showed reduced contextual fear but normal cued fear. Mice exhibited normal memory performance in the short-term version of the novel object recognition task, suggesting that PNMT mice exhibit more selective memory effects on highly emotional and/or long-term memories. Similarly, open-field activity was unaffected by epinephrine deficiency, suggesting that differences in freezing are not related to changes in overall anxiety or exploratory drive. Startle reactivity to acoustic pulses was reduced in PNMT-KO mice, whereas prepulse inhibition was increased. These findings provide further evidence for a selective role of epinephrine in contextual-fear learning and support its potential role in acoustic startle.

  12. Performance, Thermal, and Vibration Qualification Testing of Zetec Acoustic Transducers, Model Z0002659-2, Sondicator Probes

    SciTech Connect

    Jacobson, G; Gemberling, S; Lavietes, A

    2006-03-10

    This report is a result of Qualification Test Plan No.001 prepared by Anthony Lavietes. The Qualification Test Plan outlines a list of requirements for thermal and vibrational testing of Zetac's Z0002659-2 Sondicator Probe acoustic transducers (hereafter called ''transducers''). The Zetec transducers are used in a system that employs an array of 7 acoustic transducers. Qualification testing of these transducers was required since they are a modified version of a standard catalog item from the manufacturer. This report documents the thermal, vibrational, and performance testing that was performed on a sampling of these transducers in order to qualify them for flight. A total of 14 transducers were tested. All 14 passed qualification testing with no failures.

  13. The use of waveguide acoustic probes for void fraction measurement in the evaporator of BN-350-Type reactor

    SciTech Connect

    Melnikov, V.I.; Nigmatulin, B.I.

    1995-09-01

    The present paper deals with some results of the experimental studies which have been carried out to investigate the steam generation dynamics in the Field tubes of sodium-water evaporators used in the BN-350 reactors. The void fraction measurements have been taken with the aid of waveguide acoustic transducers manufactured in accordance with a specially designed technology (waveguide acoustic transducers-WAT technology). Presented in this paper also the transducer design and calibration methods, as well as the diagram showing transducers arrengment in the evaporator. The transducers under test featured a waveguide of about 4 m in length and a 200-mm long sensitive element (probe). Besides, this paper specifies the void fraction data obtained through measurements in diverse points of the evaporator. The studies revealed that the period of observed fluctuations in the void fraction amounted to few seconds and was largely dependent on the level of water in the evaporator.

  14. Acoustics

    NASA Technical Reports Server (NTRS)

    Goodman, Jerry R.; Grosveld, Ferdinand

    2007-01-01

    The acoustics environment in space operations is important to maintain at manageable levels so that the crewperson can remain safe, functional, effective, and reasonably comfortable. High acoustic levels can produce temporary or permanent hearing loss, or cause other physiological symptoms such as auditory pain, headaches, discomfort, strain in the vocal cords, or fatigue. Noise is defined as undesirable sound. Excessive noise may result in psychological effects such as irritability, inability to concentrate, decrease in productivity, annoyance, errors in judgment, and distraction. A noisy environment can also result in the inability to sleep, or sleep well. Elevated noise levels can affect the ability to communicate, understand what is being said, hear what is going on in the environment, degrade crew performance and operations, and create habitability concerns. Superfluous noise emissions can also create the inability to hear alarms or other important auditory cues such as an equipment malfunctioning. Recent space flight experience, evaluations of the requirements in crew habitable areas, and lessons learned (Goodman 2003; Allen and Goodman 2003; Pilkinton 2003; Grosveld et al. 2003) show the importance of maintaining an acceptable acoustics environment. This is best accomplished by having a high-quality set of limits/requirements early in the program, the "designing in" of acoustics in the development of hardware and systems, and by monitoring, testing and verifying the levels to ensure that they are acceptable.

  15. Decreased startle modulation during anticipation in the postpartum period in comparison to late pregnancy.

    PubMed

    Hellgren, Charlotte; Bannbers, Elin; Åkerud, Helena; Risbrough, Victoria; Poromaa, Inger Sundström

    2012-04-01

    Knowledge about healthy women’s psychophysiological adaptations during the large neuroendocrine changes of pregnancy and childbirth is essential in order to understand why these events have the potential to disrupt mental health in vulnerable individuals. This study aimed to compare startle response modulation, an objective psychophysiological measure demonstrated to be influenced by anxiety and depression, longitudinally across late pregnancy and the postpartum period. The acoustic startle response modulation was assessed during anticipation of affective images and during image viewing in 31 healthy women during gestational weeks 36–39 and again at 4 to 6 weeks postpartum. No startle modulation by affective images was observed at either time point. Significant modulation during anticipation stimuli was found at pregnancy assessment but was reduced in the postpartum period. The women rated the unpleasant images more negative and more arousing and the pleasant images more positive at the postpartum assessment. Self-reported anxiety and depressive symptoms did not change between assessments. The observed postpartum decrease in modulation of startle by anticipation suggests a relatively deactivated defense system in the postpartum period.

  16. Why do caterpillars whistle at birds? Insect defence sounds startle avian predators.

    PubMed

    Dookie, Amanda L; Young, Courtney A; Lamothe, Gilles; Schoenle, Laura A; Yack, Jayne E

    2017-05-01

    Many insects produce sounds when attacked by a predator, yet the functions of these signals are poorly understood. It is debated whether such sounds function as startle, warning or alarm signals, or merely serve to augment other defences. Direct evidence is limited owing to difficulties in disentangling the effects of sounds from other defences that often occur simultaneously in live insects. We conducted an experiment to test whether an insect sound can function as a deimatic (i.e. startle) display. Variations of a whistle of the walnut sphinx caterpillar (Amorpha juglandis) were presented to a predator, red-winged blackbirds (Agelaius phoeniceus), when birds activated a sensor while feeding on mealworms (Tenebrio molitor). Birds exposed to whistles played back at natural sound levels exhibited significantly higher startle scores (by flying away, flinching, and hopping) and took longer to return to the feeding dish than during control conditions where no sounds were played. Birds habituated to sounds during a one-hour session, but after two days the startling effects were restored. Our results provide empirical evidence that an insect sound alone can function as a deimatic display against an avian predator. We discuss how whistles might be particularly effective 'acoustic eye spots' on avian predators.

  17. The effects of startle and non-startle auditory stimuli on wrist flexion movement in Parkinson's disease.

    PubMed

    Fernandez-Del-Olmo, Miguel; Bello, Olalla; Lopez-Alonso, Virginia; Marquez, G; Sanchez, Jose A; Morenilla, Luis; Valls-Solé, Josep

    2013-08-26

    Startle stimuli lead to shorter reaction times in control subjects and Parkinson's disease (PD) patients. However, non-startle stimuli also enhance movement initiation in PD. We wanted to examine whether a startle-triggered movement would retain similar kinematic and EMG-related characteristics compared to one induced by a non-startle external cue in PD patients. In this study we investigated the electromyography pattern and the reaction time during a wrist flexion movement in response to three different stimuli: a visual imperative stimulus; visual stimulus simultaneous with a non-startle auditory stimulus and with a startle auditory stimulus. Ten PD patients and ten aged matched controls participated in this study. The reaction times were faster for startle and non-startle stimuli in comparison with the visual imperative stimulus, in both patients and control subjects. The startle cue induced a faster reaction than the non-startle cue. The electromyography pattern remained unchanged across the conditions. The results suggest that the startle reaction effect for upper limb movements are unimpaired in PD patients and has different characteristics than the effect of non-startle stimuli.

  18. Passive probing of the sound fixing and ranging channel with hydro-acoustic observations from ridge earthquakes.

    PubMed

    Evers, Läslo G; Snellen, Mirjam

    2015-04-01

    The International Monitoring System includes a hydro-acoustic part to verify the Comprehensive Nuclear-Test-Ban Treaty. Besides explosive signals, monitoring stations also detect acoustic waves from earthquakes that travel through the SOund Fixing And Ranging (SOFAR) channel. The travel times of such detections are listed in the Reviewed Event Bulletin, which is statistically evaluated for the stations located in the Pacific, Indian, and Atlantic Oceans. The celerities of ridge earthquakes are calculated to build up a homogeneous data-set, based on similar source mechanisms. The celerity is defined as the epicentral distance divided by the travel time. The global characteristics of these celerities can be well understood in terms of temperature variations in the SOFAR channel. A detailed velocity profile has been retrieved for the Atlantic Ocean where large differences (14 m/s) are found between the southern and northern parts of the basin. Propagation modeling with normal modes supports these findings, which shows that the celerity gives an estimate of the sound speed in the SOFAR channel. These results compare remarkably well with those from active experiments, showing the ability of passively probing the SOFAR channel with hydro-acoustic waves from earthquake sources.

  19. Fear conditioning facilitates rats gap detection measured by prepulse inhibition of the startle reflex

    NASA Astrophysics Data System (ADS)

    Zou, Dan; Wu, Xihong; Li, Liang

    2005-04-01

    A low-intensity acoustic event presented shortly before an intense startling sound can inhibit the acoustic startle reflex. This phenomenon is called prepulse inhibition (PPI), and is widely used as a model of sensorimotor gating in both humans and animals. Particularly, it has been used for evaluating the aging effect on the mouse's ability to detect a silent gap in otherwise continuous sounds. The present study extended this model to the emotional modulation of gap detection. The results show that a silent gap embedded in each of the two broadband noise sounds (55 dB SPL), which were delivered by two spatially separated loudspeakers, could inhibit the startle reflex that was induced by a loud sound presented from the third loudspeaker 50 ms after the gap. The inhibitory effect largely depended on the duration of the gap, with the mean duration threshold around 11 ms across 18 rats tested. Pairing the gap with foot shock in a temporally specific manner, but not in a temporally random manner, significantly reduced the duration threshold. Thus this study established a new animal behavioral model both for studying auditory temporal processing and for studying auditory signal-detection plasticity induced by emotional learning.

  20. The Neurotensin-1 Receptor Agonist PD149163 Blocks Fear-Potentiated Startle

    PubMed Central

    Shilling, Paul D.; Feifel, David

    2014-01-01

    Preliminary evidence suggests that the neuropeptide, neurotensin (NT) may regulate fear/anxiety circuits. We investigated the effects of PD149163, a NT-1 receptor agonist, on fear-potentiated startle (FPS). Sprague Dawley rats were trained to associate a white light with a mild foot shock. In one experiment, animals were treated with either subcutaneous vehicle or PD149163 (0.01, 0.1 or 1.0 mg/kg) twenty-four hours after training. Twenty minutes later their acoustic startle response in the presence or absence of the white light was tested. In a second experiment, saline and 1.0 mg/kg PD149163 were tested using a separate group of rats. In the first experiment, PD149163 produced a non-significant decrease in baseline acoustic startle at all three doses. As expected, saline treated rats exhibited significant FPS. An ANOVA of percentage FPS revealed no significant effect of treatment group overall but the high dose group did not display FPS strongly suggesting an FPS effect at this dose. This finding was confirmed in the second experiment where the high dose of PD149163 reduced percent FPS relative to saline (P<0.05). These data suggest that systemically administered NT-1 agonists modulate the neural circuitry that regulates fear and anxiety to produce dose-dependent anxiolytic-like effects on FPS. PMID:18577396

  1. Instruction-dependent modulation of the long-latency stretch reflex is associated with indicators of startle

    PubMed Central

    Ravichandran, Vengateswaran J.; Honeycutt, Claire F.; Shemmell, Jonathan; Perreault, Eric J.

    2013-01-01

    Long-latency responses elicited by postural perturbation are modulated by how a subject is instructed to respond to the perturbation, yet the neural pathways responsible for this modulation remain unclear. The goal of this study was to determine if instruction-dependent modulation is associated with activity in brainstem pathways contributing to startle. Our hypothesis was that elbow perturbations can evoked startle, indicated by activity in the sternocleidomastoid muscle (SCM). Perturbation responses were compared to those elicited by a loud acoustic stimulus, known to elicit startle. Postural perturbations and startling acoustic stimuli both evoked SCM activity, but only when a ballistic elbow extension movement was planned. Both stimuli triggered SCM activity with the same probability. When SCM activity was present, there was an associated early onset of triceps EMG, as required for the planned movement. This early EMG onset occurred at a time often attributed to long-latency stretch reflexes (75-100ms). The nature of the perturbation-triggered EMG (excitatory or inhibitory) was independent of the perturbation direction (flexion or extension) indicating that it was not a feedback response appropriate for returning the limb to its original position. The net EMG response to perturbations delivered after a movement had been planned could be explained as the sum of a stretch reflex opposing the perturbation and a startle-evoked response associated with the prepared movement. These results demonstrate that rapid perturbations can trigger early release of a planned ballistic movement, and that this release is associated with activity in the brainstem pathways contributing to startle reflexes. PMID:23811739

  2. Respiratory modulation of startle eye blink: a new approach to assess afferent signals from the respiratory system.

    PubMed

    Schulz, André; Schilling, Thomas M; Vögele, Claus; Larra, Mauro F; Schächinger, Hartmut

    2016-11-19

    Current approaches to assess interoception of respiratory functions cannot differentiate between the physiological basis of interoception, i.e. visceral-afferent signal processing, and the psychological process of attention focusing. Furthermore, they typically involve invasive procedures, e.g. induction of respiratory occlusions or the inhalation of CO2-enriched air. The aim of this study was to test the capacity of startle methodology to reflect respiratory-related afferent signal processing, independent of invasive procedures. Forty-two healthy participants were tested in a spontaneous breathing and in a 0.25 Hz paced breathing condition. Acoustic startle noises of 105 dB(A) intensity (50 ms white noise) were presented with identical trial frequency at peak and on-going inspiration and expiration, based on a new pattern detection method, involving the online processing of the respiratory belt signal. The results show the highest startle magnitudes during on-going expiration compared with any other measurement points during the respiratory cycle, independent of whether breathing was spontaneous or paced. Afferent signals from slow adapting phasic pulmonary stretch receptors may be responsible for this effect. This study is the first to demonstrate startle modulation by respiration. These results offer the potential to apply startle methodology in the non-invasive testing of interoception-related aspects in respiratory psychophysiology.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.

  3. Startle evoked movement is delayed in older adults: implications for brainstem processing in the elderly

    PubMed Central

    Tresch, Ursina A.; Perreault, Eric J.; Honeycutt, Claire F.

    2014-01-01

    Abstract Little attention has been given to how age affects the neural processing of movement within the brainstem. Since the brainstem plays a critical role in motor control throughout the whole body, having a clear understanding of deficits in brainstem function could provide important insights into movement deficits in older adults. A unique property of the startle reflex is its ability to involuntarily elicit planned movements, a phenomenon referred to as startReact. The noninvasive startReact response has previously been used to probe both brainstem utilization and motor planning. Our objective was to evaluate deficits in startReact hand extension movements in older adults. We hypothesized that startReact hand extension will be intact but delayed. Electromyography was recorded from the sternocleidomastoid (SCM) muscle to detect startle and the extensor digitorum communis (EDC) to quantify movement onset in both young (24 ± 1) and older adults (70 ± 11). Subjects were exposed to a startling loud sound when prepared to extend their hand. Trials were split into those where a startle did (SCM+) and did not (SCM−) occur. We found that startReact was intact but delayed in older adults. SCM+ onset latencies were faster than SCM− trials in both the populations, however, SCM+ onset latencies were slower in older adults compared to young (Δ = 8 msec). We conclude that the observed age‐related delay in the startReact response most likely arises from central processing delays within the brainstem. PMID:24907294

  4. Modulation of Prepulse Inhibition and Startle Reflex by Emotions: A Comparison between Young and Older Adults

    PubMed Central

    Le Duc, Jolyanne; Fournier, Philippe; Hébert, Sylvie

    2016-01-01

    This study examined whether or not the acoustic startle response and sensorimotor gating may be modulated by emotions differentially between young and older adults. Two groups of participants (mean age Young: 24 years old; Elderly: 63.6 years old) were presented with three types of auditory stimuli (Startle alone, High or Low frequency Prepulse) while viewing pleasant, neutral, or unpleasant images. Electromyographic activity of the eyeblink response was measured. Results show that older adults displayed diminished eyeblink responses whereas younger adults displayed enhanced eyeblink responses when viewing negative images. Sensorimotor gating also differed between young and older adults, with enhanced sensorimotor gating abilities while viewing positive pictures in older adults and diminished abilities while viewing negative pictures among younger adults. These results argue in favor of a differential emotional influence on the sensorimotor abilities of young and older adults, with a positivity bias among the latter. PMID:26941643

  5. Go-activation endures following the presentation of a stop-signal: evidence from startle.

    PubMed

    Drummond, Neil M; Cressman, Erin K; Carlsen, Anthony N

    2017-01-01

    It has been proposed that, in a stop-signal task (SST), independent go- and stop-processes "race" to control behavior. If the go-process wins, an overt response is produced, whereas, if the stop-process wins, the response is withheld. One prediction that follows from this proposal is that, if the activation associated with one process is enhanced, it is more likely to win the race. We looked to determine whether these initiation and inhibition processes (and thus response outcomes) could be manipulated by using a startling acoustic stimulus (SAS), which has been shown to provide additional response activation. In the present study, participants were to respond to a visual go-stimulus; however, if a subsequent stop-signal appeared, they were to inhibit the response. The stop-signal was presented at a delay corresponding to a probability of responding of 0.4 (determined from a baseline block of trials). On stop-trials, a SAS was presented either simultaneously with the go-signal or stop-signal or 100, 150, or 200 ms following the stop-signal. Results showed that presenting a SAS during stop-trials led to an increase in probability of responding when presented with or following the stop-signal. The latency of SAS responses at the stop-signal + 150 ms and stop-signal + 200 ms probe times suggests that they would have been voluntarily inhibited but instead were involuntarily initiated by the SAS. Thus results demonstrate that go-activation endures even 200 ms following a stop-signal and remains accessible well after the response has been inhibited, providing evidence against a winner-take-all race between independent go- and stop-processes.

  6. Full bandwidth calibration procedure for acoustic probes containing a pressure and particle velocity sensor.

    PubMed

    Basten, Tom G H; de Bree, Hans-Elias

    2010-01-01

    Calibration of acoustic particle velocity sensors is still difficult due to the lack of standardized sensors to compare with. Recently it is shown by Jacobsen and Jaud [J. Acoust. Soc. Am. 120, 830-837 (2006)] that it is possible to calibrate a sound pressure and particle velocity sensor in free field conditions at higher frequencies. This is done by using the known acoustic impedance at a certain distance of a spherical loudspeaker. When the sound pressure is measured with a calibrated reference microphone, the particle velocity can be calculated from the known impedance and the measured pressure. At lower frequencies, this approach gives unreliable results. The method is now extended to lower frequencies by measuring the acoustic pressure inside the spherical source. At lower frequencies, the sound pressure inside the sphere is proportional to the movement of the loudspeaker membrane. If the movement is known, the particle velocity in front of the loudspeaker can be derived. This low frequency approach is combined with the high frequency approach giving a full bandwidth calibration procedure which can be used in free field conditions using a single calibration setup. The calibration results are compared with results obtained with a standing wave tube.

  7. Miniature probe for mechanical properties of vascular lesions using acoustic radiation force optical coherence elastography (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Qu, Yueqiao; Ma, Teng; He, Youmin; Yu, Mingyue; Li, Rui; Zhu, Jiang; Dai, Cuixia; Piao, Zhonglie; Shung, K. Kirk; Zhou, Qifa; Chen, Zhongping

    2016-03-01

    Changes in tissue biomechanical properties often signify the onset and progression of diseases, such as in determining the vulnerability of atherosclerotic plaques. Acoustic radiation force optical coherence elastography (ARF-OCE) has been used in the detection of tissue elasticity to obtain high-resolution elasticity maps. We have developed a probe-based ARF-OCE technology that utilizes a miniature 10 MHz ring ultrasonic transducer for excitation and Doppler optical coherence tomography (OCT) for detection. The transducer has a small hole in the center for the OCT light to propagate through. This allows for a confocal stress field and light detection within a small region for high sensitivity and localized excitation. This device is a front-facing probe that is only 3.5 mm in diameter and it is the smallest ARF-OCE catheter to the best of our knowledge. We have tested the feasibility of the probe by measuring the point displacement of an agarose tissue-mimicking phantom using different ARF excitation voltages. Small displacement values ranging from 30 nm to 90 nm have been detected and are shown to be directly proportional to the excitation voltage as expected. We are currently working on obtaining 2D images using a scanning mechanism. We will be testing to capture 2D elastograms of phantoms to further verify feasibility, and eventually characterize the mechanical properties of cardiovascular tissue. With its high portability and sensitivity, this novel technology can be applied to the diagnosis and characterization of vulnerable atherosclerotic plaques.

  8. Nuclear Quadrupole Resonance (NQR) Method and Probe for Generating RF Magnetic Fields in Different Directions to Distinguish NQR from Acoustic Ringing Induced in a Sample

    DTIC Science & Technology

    1997-08-01

    77,719 TITLE OF THE INVENTION NUCLEAR QUADRUPOLE RESONANCE ( NQR ) METHOD AND PROBE FOR GENERATING RF MAGNETIC FIELDS IN DIFFERENT DIRECTIONS TO...DISTINGUISH NQR FROM ACOUSTIC RINGING INDUCED IN A SAMPLE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a...nuclear quadrupole 15 resonance ( NQR ) method and probe for generating RF magnetic fields in different directions towards a sample. More specifically

  9. Startling Sweet Temptations: Hedonic Chocolate Deprivation Modulates Experience, Eating Behavior, and Eyeblink Startle

    PubMed Central

    Blechert, Jens; Naumann, Eva; Schmitz, Julian; Herbert, Beate M.; Tuschen-Caffier, Brunna

    2014-01-01

    Many individuals restrict their food intake to prevent weight gain. This restriction has both homeostatic and hedonic effects but their relative contribution is currently unclear. To isolate hedonic effects of food restriction, we exposed regular chocolate eaters to one week of chocolate deprivation but otherwise regular eating. Before and after this hedonic deprivation, participants viewed images of chocolate and images of high-calorie but non-chocolate containing foods, while experiential, behavioral and eyeblink startle responses were measured. Compared to satiety, hedonic deprivation triggered increased chocolate wanting, liking, and chocolate consumption but also feelings of frustration and startle potentiation during the intertrial intervals. Deprivation was further characterized by startle inhibition during both chocolate and food images relative to the intertrial intervals. Individuals who responded with frustration to the manipulation and those who scored high on a questionnaire of impulsivity showed more relative startle inhibition. The results reveal the profound effects of hedonic deprivation on experiential, behavioral and attentional/appetitive response systems and underscore the role of individual differences and state variables for startle modulation. Implications for dieting research and practice as well as for eating and weight disorders are discussed. PMID:24416437

  10. Startling sweet temptations: hedonic chocolate deprivation modulates experience, eating behavior, and eyeblink startle.

    PubMed

    Blechert, Jens; Naumann, Eva; Schmitz, Julian; Herbert, Beate M; Tuschen-Caffier, Brunna

    2014-01-01

    Many individuals restrict their food intake to prevent weight gain. This restriction has both homeostatic and hedonic effects but their relative contribution is currently unclear. To isolate hedonic effects of food restriction, we exposed regular chocolate eaters to one week of chocolate deprivation but otherwise regular eating. Before and after this hedonic deprivation, participants viewed images of chocolate and images of high-calorie but non-chocolate containing foods, while experiential, behavioral and eyeblink startle responses were measured. Compared to satiety, hedonic deprivation triggered increased chocolate wanting, liking, and chocolate consumption but also feelings of frustration and startle potentiation during the intertrial intervals. Deprivation was further characterized by startle inhibition during both chocolate and food images relative to the intertrial intervals. Individuals who responded with frustration to the manipulation and those who scored high on a questionnaire of impulsivity showed more relative startle inhibition. The results reveal the profound effects of hedonic deprivation on experiential, behavioral and attentional/appetitive response systems and underscore the role of individual differences and state variables for startle modulation. Implications for dieting research and practice as well as for eating and weight disorders are discussed.

  11. Auditory startle reflex inhibited by preceding self-action.

    PubMed

    Kawachi, Yousuke; Matsue, Yoshihiko; Shibata, Michiaki; Imaizumi, Osamu; Gyoba, Jiro

    2014-01-01

    A startle reflex to a startle pulse is inhibited when preceded by a prestimulus. We introduced a key-press action (self-action) or an 85 dB noise burst as a prestimulus, followed by a 115 dB noise burst as a startle pulse. We manipulated temporal offsets between the prestimulus and the startle pulse from 30-1,500 ms to examine whether self-action modulates the startle reflex and the temporal properties of the modulatory effect. We assessed eyeblink reflexes by electromyography. Both prestimuli decreased reflexes compared to pulse-alone trials. Moreover, the temporal windows of inhibition were different between the types of prestimuli. A faster maximal inhibition and narrower temporal window in self-action trials suggest that preceding self-action inhibits the startle reflex and allows prediction of the coming pulse in different ways from auditory prestimuli.

  12. Investigation of the effects of head irradiation with gamma rays and protons on startle and pre-pulse inhibition behavior in mice.

    PubMed

    Haerich, Paul; Eggers, Cara; Pecaut, Michael J

    2012-05-01

    With the increased international emphasis on manned space exploration, there is a growing need to understand the impact of the spaceflight environment on health and behavior. One particularly important aspect of this environment is low-dose radiation. In the present studies, we first characterized the γ- and proton-irradiation dose effect on acoustic startle and pre-pulse inhibition behaviors in mice exposed to 0-5 Gy brain-localized irradiation, and assessed these effects 2 days later. Subsequently, we used 2 Gy to assess the time course of γ- and proton-radiation effects on startle reactivity 0-8 days after exposure. Exposures targeted the brain to minimize the impact of peripheral inflammation-induced sickness behavior. The effects of radiation on startle were subtle and acute. Radiation reduced the startle response at 2 and 5 Gy. Following a 2-Gy exposure, the response reached a minimum at the 2-day point. Proton and γ-ray exposures did not differ in their impact on startle. We found there were no effects of radiation on pre-pulse inhibition of the startle response.

  13. Reduced mobility but unaffected startle response in female rats exposed to prenatal dexamethasone: different sides to a phenotype.

    PubMed

    Kjaer, S L; Wegener, G; Rosenberg, R; Hougaard, K S

    2010-08-01

    An adverse fetal environment is strongly associated with behavioral and emotional development in later life, and environmental interactions with the genome are essential in the development of pathophysiology. This implicates that a genetic vulnerability or other predisposition may interact with the environment and stressful life events to trigger mental disease. The startle reflex is highly sensitive to fear and anxiety in humans and animals. Elevated startle magnitude has been proposed as a marker for neurodevelopmental disorders. We have recently established an animal model for possible development of anxiety, where female rats are exposed to two stressful life events, during prenatal life and as adolescents, respectively. A blood sampling procedure 3 months prior to startle testing has previously been found to increase basal startle, but only in prenatally stressed rats. As the experimental procedure of acoustic startle response (ASR) measurement resembles the aversive blood sampling procedure, this suggests that effects on ASR may be caused by aversive contextual similarities between blood sampling under restraint and the ASR test. In the present study, postnatal blood sampling was replaced by another dissimilar stressful event. Animals exposed to a high prenatal glucocorticoid level (i.e. 150 mug dexamethasone/kg) were statistically significantly more immobile in the forced swim test (FST) than animals exposed to a lower level of dexamethasone (50 mug/kg) and control animals. Exposure to a novel contextual stressor at 3 months of age (FST) was unassociated with changes in basal startle. These data suggest, since the high prenatal dexamethasone group showed increased immobility in the FST but coped equally well with controls in the ASR, that the outcome of environmental influences is determined by the individual circumstances as different situations require different coping abilities in the same individual.

  14. Acoustic Pulse Echoes Probed with Time-Resolved X-Ray Triple-Crystal Diffractometry

    SciTech Connect

    Hayashi, Yujiro; Tanaka, Yoshihito; Kirimura, Tomoyuki; Ishikawa, Tetsuya; Tsukuda, Noboru; Kuramoto, Eiichi

    2006-03-24

    Acoustic pulse echoes generated by femtosecond laser irradiation were detected using time-resolved x-ray triple-crystal diffractometry. The determined time-dependent longitudinal strain component for pulse echoes in silicon and gallium arsenide plates showed that the polarity of the strain pulse was dependent on the optically induced initial stress, and that the bipolar pulse waveform was gradually deformed and broadened in the course of propagation. The three-dimensional wave front distortion of pulse echoes was shown simply as the pulse duration broadening, which was consistent with a boundary roughness for an unpolished plate.

  15. Transverse mechanical properties of cell walls of single living plant cells probed by laser-generated acoustic waves.

    PubMed

    Gadalla, Atef; Dehoux, Thomas; Audoin, Bertrand

    2014-05-01

    Probing the mechanical properties of plant cell wall is crucial to understand tissue dynamics. However, the exact symmetry of the mechanical properties of this anisotropic fiber-reinforced composite remains uncertain. For this reason, biologically relevant measurements of the stiffness coefficients on individual living cells are a challenge. For this purpose, we have developed the single-cell optoacoustic nanoprobe (SCOPE) technique, which uses laser-generated acoustic waves to probe the stiffness, thickness and viscosity of live single-cell subcompartments. This all-optical technique offers a sub-micrometer lateral resolution, nanometer in-depth resolution, and allows the non-contact measurement of the mechanical properties of live turgid tissues without any assumption of mechanical symmetry. SCOPE experiments reveal that single-cell wall transverse stiffness in the direction perpendicular to the epidermis layer of onion cells is close to that of cellulose. This observation demonstrates that cellulose microfibrils are the main load-bearing structure in this direction, and suggests strong bonding of microfibrils by hemicelluloses. Altogether our measurement of the viscosity at high frequencies suggests that the rheology of the wall is dominated by glass-like dynamics. From a comparison with literature, we attribute this behavior to the influence of the pectin matrix. SCOPE's ability to unravel cell rheology and cell anisotropy defines a new class of experiments to enlighten cell nano-mechanics.

  16. The effect of choice on the physiology of emotion: an affective startle modulation study.

    PubMed

    Genevsky, Alexander; Gard, David E

    2012-04-01

    The affective startle modulation task has been an important measure in understanding physiological aspects of emotion and motivational responses. Research utilizing this method has relied primarily on a 'passive' viewing paradigm, which stands in contrast to everyday life where much of emotion and motivation involves some active choice or agency. The present study investigated the role of choice on the physiology of emotion. Eighty-four participants were randomized into 'choice' (n=44) or 'no-choice' (n=40) groups distinguished by the ability to choose between stimuli. EMG eye blink responses were recorded in both anticipation and stimulus viewing. Results indicated a significant attenuation of the startle magnitude in choice condition trials (relative to no-choice) across all picture categories and probe times. We interpret these findings as an indication that the act of choice may decrease one's defensive response, or conversely, lacking choice may heighten the defensive response. Implications for future research are discussed.

  17. The gap-startle paradigm to assess auditory temporal processing: Bridging animal and human research.

    PubMed

    Fournier, Philippe; Hébert, Sylvie

    2016-05-01

    The gap-prepulse inhibition of the acoustic startle (GPIAS) paradigm is the primary test used in animal research to identify gap detection thresholds and impairment. When a silent gap is presented shortly before a loud startling stimulus, the startle reflex is inhibited and the extent of inhibition is assumed to reflect detection. Here, we applied the same paradigm in humans. One hundred and fifty-seven normal-hearing participants were tested using one of five gap durations (5, 25, 50, 100, 200 ms) in one of the following two paradigms-gap-embedded in or gap-following-the continuous background noise. The duration-inhibition relationship was observable for both conditions but followed different patterns. In the gap-embedded paradigm, GPIAS increased significantly with gap duration up to 50 ms and then more slowly up to 200 ms (trend only). In contrast, in the gap-following paradigm, significant inhibition-different from 0--was observable only at gap durations from 50 to 200 ms. The finding that different patterns are found depending on gap position within the background noise is compatible with distinct mechanisms underlying each of the two paradigms.

  18. Individual differences in behavioral activation and cardiac vagal control influence affective startle modification.

    PubMed

    Yang, Xiao; Friedman, Bruce H

    2017-04-01

    The startle response (SR) has a close relationship with stress responses. Startle modification (SRM) has been widely used to study stress disorders (e.g., posttraumatic stress disorder). The framework of the behavioral inhibition and activation systems (BIS/BAS) has been thought to correspond with withdrawal and approach motivational processes underlying affective SRM and can influence stress reactivity. Vagally-mediated cardiac activity as indexed by heart rate variability (HRV) has been associated with SRM and regulatory processes during stress. In the present study, the influence of individual differences in the BIS/BAS and resting HRV on affective SRM were examined. Eighty-six subjects viewed affective pictures while acoustic SR stimuli were delivered. Individual differences in motivation were measured by the BIS/BAS scales. The magnitude of SR was assessed as electromyographic activity of the SR eyeblink during pictures of different valences. Resting HRV was derived from electrocardiography. In contrast to previous studies, the present results showed that startle inhibition and potentiation were related to BAS and HRV, but not to BIS. There was also an interaction of BAS and HRV, indicating that the relationship between HRV and SRM strengthened as BAS scores decreased. The present findings suggest that BAS may relate to both withdrawal and approach, and trait stress reactivity is influenced by BAS and cardiac vagal activity. In addition, BAS moderates the relationship between cardiac vagal activity and SRM. These findings have both theoretical and practical implications for the study of SRM, stress disorders, and health.

  19. Versatility of fear-potentiated startle paradigms for assessing human conditioned fear extinction and return of fear.

    PubMed

    Norrholm, Seth D; Anderson, Kemp M; Olin, Ilana W; Jovanovic, Tanja; Kwon, Cliffe; Warren, Victor T; McCarthy, Alexander; Bosshardt, Lauren; Sabree, Justin; Duncan, Erica J; Rothbaum, Barbara O; Bradley, Bekh

    2011-01-01

    Fear conditioning methodologies have often been employed as testable models for assessing learned fear responses in individuals with anxiety disorders such as post-traumatic stress disorder (PTSD) and specific phobia. One frequently used paradigm is measurement of the acoustic startle reflex under conditions that mimic anxiogenic and fear-related conditions. For example, fear-potentiated startle is the relative increase in the frequency or magnitude of the acoustic startle reflex in the presence of a previously neutral cue (e.g., colored shape; termed the conditioned stimulus or CS+) that has been repeatedly paired with an aversive unconditioned stimulus (e.g., airblast to the larynx). Our group has recently used fear-potentiated startle paradigms to demonstrate impaired fear extinction in civilian and combat populations with PTSD. In the current study, we examined the use of either auditory or visual CSs in a fear extinction protocol that we have validated and applied to human clinical conditions. This represents an important translational bridge in that numerous animal studies of fear extinction, upon which much of the human work is based, have employed the use of auditory CSs as opposed to visual CSs. Participants in both the auditory and visual groups displayed robust fear-potentiated startle to the CS+, clear discrimination between the reinforced CS+ and non-reinforced CS-, significant extinction to the previously reinforced CS+, and marked spontaneous recovery. We discuss the current results as they relate to future investigations of PTSD-related impairments in fear processing in populations with diverse medical and psychiatric histories.

  20. Acoustic phonons in chrysotile asbestos probed by high-resolution inelastic x-ray scattering

    SciTech Connect

    Mamontov, Eugene; Vakhrushev, S. B.; Kumzerov, Yu. A,; Alatas, A.

    2009-01-01

    Acoustic phonons in an individual, oriented fiber of chrysotile asbestos (chemical formula Mg{sub 3}Si{sub 2}O{sub 5}(OH){sub 4}) were observed at room temperature in the inelastic x-ray measurement with a very high (meV) resolution. The x-ray scattering vector was aligned along [1 0 0] direction of the reciprocal lattice, nearly parallel to the long axis of the fiber. The latter coincides with [1 0 0] direction of the direct lattice and the axes of the nano-channels. The data were analyzed using a damped harmonic oscillator model. Analysis of the phonon dispersion in the first Brillouin zone yielded the longitudinal sound velocity of (9200 {+-} 600) m/s.

  1. Wideband spherically focused PVDF acoustic sources for calibration of ultrasound hydrophone probes.

    PubMed

    Selfridge, A; Lewin, P A

    2000-01-01

    Several broadband sources have been developed for the purpose of calibrating hydrophones. The specific configuration described is intended for the calibration of hydrophones In a frequency range of 1 to 40 MHz. All devices used 25 /spl mu/m film of PVDF bonded to a matched backing. Two had radii of curvatures (ROC) of 25.4 and 127 mm with f numbers of 3.8 and 19, respectively. Their active element diameter was 0.28 in (6.60 mm). The active diameter of the third source used was 25 mm, and it had an ROC of 254 mm and an f number of 10. The use of a focused element minimized frequency-dependent diffraction effects, resulting in a smooth variation of acoustic pressure at the focus from 1 to 40 MHz. Also, using a focused PVDF source permitted calibrations above 20 MHz without resorting to harmonic generation via nonlinear propagation.

  2. Startle Response in Progressive Myoclonic Epilepsy.

    PubMed

    Kızıltan, Meral E; Gündüz, Ayşegül; Coşkun, Tülin; Delil, Şakir; Pazarcı, Nevin; Özkara, Çiğdem; Yeni, Naz

    2017-03-01

    Cortical reflex myoclonus is a typical feature of progressive myoclonic epilepsy (PME) in which it is accompanied by other types of mostly drug-resistant seizures and progressive neurological signs. Although PME is characterized by cortical hyperexcitability, studies have demonstrated atrophy and degenerative changes in the brainstem in various types of PME. Thus, we have questioned whether any stimuli may trigger a hyperactive response of brainstem reticular formation in PME and investigated the startle reflex in individuals with PME. We recorded the auditory startle response (ASR) and the startle response to somatosensory inputs (SSS) in patients with PME, and compared the results with healthy volunteers and patients with other types of drug-resistant epilepsy. All patients were using antiepileptic drugs (AEDs), 12 were on multiple AEDs. The probability of ASR was significantly lower and mean onset latency was longer in patients with PME compared with other groups. SSS responses over all muscles were low in both the PME and drug-resistant epilepsy groups; however, the differences were not statistically significant. The presence of a response over the biceps brachii muscle was zero in the PME group and showed a borderline difference compared with the other groups. Decreased probability and prolonged latencies of ASR in PME indicate inhibition of reflex circuit. A trend for decreased responses of SSS suggests hypoactive SSS in both PME and other epilepsy groups. Hypoactive ASR in PME and hypoactive SSS in both PME and other epilepsies may be attributed to the degeneration of pontine reticular nuclei in PME and functional inhibition by AEDs in both disorders.

  3. Combining AFM and Acoustic Probes to Reveal Changes in the Elastic Stiffness Tensor of Living Cells

    PubMed Central

    Nijenhuis, Nadja; Zhao, Xuegen; Carisey, Alex; Ballestrem, Christoph; Derby, Brian

    2014-01-01

    Knowledge of how the elastic stiffness of a cell affects its communication with its environment is of fundamental importance for the understanding of tissue integrity in health and disease. For stiffness measurements, it has been customary to quote a single parameter quantity, e.g., Young’s modulus, rather than the minimum of two terms of the stiffness tensor required by elasticity theory. In this study, we use two independent methods (acoustic microscopy and atomic force microscopy nanoindentation) to characterize the elastic properties of a cell and thus determine two independent elastic constants. This allows us to explore in detail how the mechanical properties of cells change in response to signaling pathways that are known to regulate the cell’s cytoskeleton. In particular, we demonstrate that altering the tensioning of actin filaments in NIH3T3 cells has a strong influence on the cell's shear modulus but leaves its bulk modulus unchanged. In contrast, altering the polymerization state of actin filaments influences bulk and shear modulus in a similar manner. In addition, we can use the data to directly determine the Poisson ratio of a cell and show that in all cases studied, it is less than, but very close to, 0.5 in value. PMID:25296302

  4. Planning of Ballistic Movement following Stroke: Insights from the Startle Reflex

    PubMed Central

    Honeycutt, Claire Fletcher; Perreault, Eric Jon

    2012-01-01

    Following stroke, reaching movements are slow, segmented, and variable. It is unclear if these deficits result from a poorly constructed movement plan or an inability to voluntarily execute an appropriate plan. The acoustic startle reflex provides a means to initiate a motor plan involuntarily. In the presence of a movement plan, startling acoustic stimulus triggers non-voluntary early execution of planned movement, a phenomenon known as the startReact response. In unimpaired individuals, the startReact response is identical to a voluntarily initiated movement, except that it is elicited 30–40 ms. As the startReact response is thought to be mediated by brainstem pathways, we hypothesized that the startReact response is intact in stroke subjects. If startReact is intact, it may be possible to elicit more task-appropriate patterns of muscle activation than can be elicited voluntarily. We found that startReact responses were intact following stroke. Responses were initiated as rapidly as those in unimpaired subjects, and with muscle coordination patterns resembling those seen during unimpaired volitional movements. Results were striking for elbow flexion movements, which demonstrated no significant differences between the startReact responses elicited in our stroke and unimpaired subject groups. The results during planned extension movements were less straightforward for stroke subjects, since the startReact response exhibited task inappropriate activity in the flexors. This inappropriate activity diminished over time. This adaptation suggests that the inappropriate activity was transient in nature and not related to the underlying movement plan. We hypothesize that the task-inappropriate flexor activity during extension results from an inability to suppress the classic startle reflex, which primarily influences flexor muscles and adapts rapidly with successive stimuli. These results indicate that stroke subjects are capable of planning ballistic elbow movements

  5. A laser probe based on a Sagnac interferometer with fast mechanical scan for RF surface and bulk acoustic wave devices.

    PubMed

    Hashimoto, Ken-ya; Kashiwa, Keiskue; Wu, Nan; Omori, Tatsuya; Yamaguchi, Masatsune; Takano, Osamu; Meguro, Sakae; Akahane, Koichi

    2011-01-01

    This paper describes the development of a phasesensitive laser probe with fast mechanical scan for RF surface and bulk acoustic wave (SAW/BAW) devices. The Sagnac interferometer composed of micro-optic elements was introduced for the selective detection of RF vertical motion associated with RF SAW/BAW propagation and vibration. A high-pass characteristic of the interferometer makes the measurement very insensitive to low-frequency vibration. This feature allows us to apply the fast mechanical scan to the interferometric measurement without badly sacrificing its SNR and spatial resolution. The system was applied to the visualization of a field pattern on the vibrating surface of an RF BAW resonator operating in the 2 GHz range. The field pattern was obtained in 17 min as a 2-D image (500 × 750 pixel with 0.4 μm resolution and SNR of 40 dB). The system was also applied to the characterization of an RF SAW resonator operating in the 1 GHz range, and the applicability of the system was demonstrated.

  6. Assessment of Startle Response and Its Prepulse Inhibition Using Posturography: Pilot Study

    PubMed Central

    Polechoński, Jacek; Juras, Grzegorz; Słomka, Kajetan; Błaszczyk, Janusz; Małecki, Andrzej; Nawrocka, Agnieszka

    2016-01-01

    Purpose. The aim of this study was to evaluate the possibility of using static posturography in the assessment of sensorimotor gating. Subjects and Methods. Fourteen subjects took part in the experiment. The inhibitory mechanisms of startle reflex were used as the measure of sensorimotor gating. It was evoked by a strong acoustic stimulus (106 dB SPL, 40 ms) which was preceded by the weaker similar signal (80 dB SPL, 20 ms). A stabilographic platform was used to measure sensorimotor gating. Results. Results of static posturography show that the postural sway caused by the reaction to a strong acoustic stimulus is significantly smaller when this stimulus is preceded by the signal of lower intensity (prepulse). Such assessment is only possible in eyes open conditions. Conclusions. Static posturography can be simple and effective method used for diagnosis of sensorimotor gating in humans. PMID:27314041

  7. Integrated cantilever fabrication and system development for ultrasonic and acoustic scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Olson, Stephen; Sankaran, Balasubramanian; Altemus, Bruce; Xu, Bai; Geer, Robert

    2005-05-01

    Although the conventional optical lever technology typically used for scanning probe microscope applications has proven highly sensitive, accurate, and cost effective for most applications involving micromachined cantilever deflection measurements, frequency limitations and space needs limit its applicability to emerging ultrasonic-based SPM applications. Recently, the fabrication of cantilevers integrated with actuation and sensing components has opened avenues for feedback-based driving of micromachined cantilevers at higher-order resonance frequencies while sensing average deflection without the need for an optical deflection pathway for average deflection sensing. The work presented here will review recent efforts by our group in fabricating micromachined cantilevers with integrated piezoresistive deflection-sensing components combined with integrated ZnO actuation layers to induce cantilever deflection. These cantilevers are being fabricated for use in a heterodyne force microscopy system (HFM) to enable SPM imaging contrast based on viscoelastic response of a surface in contact with a micromachined tip wherein active-feedback technology is being applied to maintain ultrasonic tip excitation at higher order cantilever resonances. The first and second-pass fabrication results will be presented and reviewed regarding cantilever release and ZnO actuator (and electrode) fabrication. Dynamic response data from these structures, measured via laser Doppler vibrometery reveal the expected resonance structure for a cantilever of these dimensions.

  8. Differential Neural Responses Underlying the Inhibition of the Startle Response by Pre-Pulses or Gaps in Mice

    PubMed Central

    Moreno-Paublete, Rocio; Canlon, Barbara; Cederroth, Christopher R.

    2017-01-01

    Gap pre-pulse inhibition of the acoustic startle (GPIAS) is a behavioral paradigm used for inferring the presence of tinnitus in animal models as well as humans. In contrast to pre-pulse inhibition (PPI), the neural circuitry controlling GPIAS is poorly understood. To increase our knowledge on GPIAS, a comparative study with PPI was performed in mice combining these behavioral tests and c-Fos activity mapping in brain areas involved in the inhibition of the acoustic startle reflex (ASR). Both pre-pulses and gaps efficiently inhibited the ASR and abolished the induction of c-Fos in the pontine reticular nucleus. Differential c-Fos activation was found between PPI and GPIAS in the forebrain whereby PPI activated the lateral globus pallidus and GPIAS activated the primary auditory cortex. Thus, different neural maps are regulating the inhibition of the startle response by pre-pulses or gaps. To further investigate this differential response to PPI and GPIAS, we pharmacologically disrupted PPI and GPIAS with D-amphetamine or Dizocilpine (MK-801) to target dopamine efflux and to block NMDA receptors, respectively. Both D-amp and MK-801 efficiently decreased PPI and GPIAS. We administered Baclofen, an agonist GABAB receptor, but failed to detect any robust rescue of the effects of D-amp and MK-801 suggesting that PPI and GPIAS are GABAB-independent. These novel findings demonstrate that the inhibition of the ASR by pre-pulses or gaps is orchestrated by different neural pathways. PMID:28239338

  9. Differential Neural Responses Underlying the Inhibition of the Startle Response by Pre-Pulses or Gaps in Mice.

    PubMed

    Moreno-Paublete, Rocio; Canlon, Barbara; Cederroth, Christopher R

    2017-01-01

    Gap pre-pulse inhibition of the acoustic startle (GPIAS) is a behavioral paradigm used for inferring the presence of tinnitus in animal models as well as humans. In contrast to pre-pulse inhibition (PPI), the neural circuitry controlling GPIAS is poorly understood. To increase our knowledge on GPIAS, a comparative study with PPI was performed in mice combining these behavioral tests and c-Fos activity mapping in brain areas involved in the inhibition of the acoustic startle reflex (ASR). Both pre-pulses and gaps efficiently inhibited the ASR and abolished the induction of c-Fos in the pontine reticular nucleus. Differential c-Fos activation was found between PPI and GPIAS in the forebrain whereby PPI activated the lateral globus pallidus and GPIAS activated the primary auditory cortex. Thus, different neural maps are regulating the inhibition of the startle response by pre-pulses or gaps. To further investigate this differential response to PPI and GPIAS, we pharmacologically disrupted PPI and GPIAS with D-amphetamine or Dizocilpine (MK-801) to target dopamine efflux and to block NMDA receptors, respectively. Both D-amp and MK-801 efficiently decreased PPI and GPIAS. We administered Baclofen, an agonist GABAB receptor, but failed to detect any robust rescue of the effects of D-amp and MK-801 suggesting that PPI and GPIAS are GABAB-independent. These novel findings demonstrate that the inhibition of the ASR by pre-pulses or gaps is orchestrated by different neural pathways.

  10. Low startle magnitude may be a behavioral marker of vulnerability to cocaine addiction.

    PubMed

    Wheeler, Marina G; Duncan, Erica; Davis, Michael

    2017-01-01

    Cocaine addicted men have low startle magnitude persisting during prolonged abstinence. Low startle rats show greater cocaine self-administration than high startle rats. Low startle may be a marker of a vulnerability to heightened cocaine-related behaviors in rats and similarly may be a marker of vulnerability to cocaine addiction in humans.

  11. STS-70 Discovery launch startling the birds

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Startled birds scatter as the stillness of a summer morning is broken by a giant's roar. The Space Shuttle Discovery thundered into space from launch Pad 39-B at 9:41:55:078 a.m. EDT. STS-70 is the 70th Shuttle flight overall, the 21st for Discovery (OV- 103), and the fourth Shuttle flight in 1995. On board for the nearly eight-day mission are a crew of five: Commander Terence 'Tom' Hendricks; Pilot Kevin R. Kregel; and Mission Specialists Nancy Jane Currie, Donald A. Thomas and Mary Ellen Weber. The crew's primary objective is to deploy the Tracking and Data Relay Satellite-G (TDRS-G), which will join a constellation of other TDRS spacecraft already on orbit.

  12. Extreme startle and photomyoclonic response in severe hypocalcaemia.

    PubMed

    Moccia, Marcello; Erro, Roberto; Nicolella, Elvira; Striano, Pasquale; Striano, Salvatore

    2014-03-01

    We report the case of 62-year-old woman referred to our department because of a clinical suspicion of tonic-clonic seizures. Clinical examination revealed an exaggerated startle reflex, EEG showed a photomyoclonic response, and blood tests indicated severe hypocalcaemia. Additional clinical data, treatment strategies, and long-term follow-up visits were reported. The present report discusses the difficulties in distinguishing between epileptic and non-epileptic startles, and shows, for the first time, exaggerated startle reflex and extreme photomyoclonic response due to severe hypocalcaemia.

  13. Startle and blink reflex in high functioning autism.

    PubMed

    Erturk, Ozdem; Korkmaz, Baris; Alev, Gulce; Demirbilek, Veysi; Kiziltan, Meral

    2016-06-01

    An important clinical feature of autism is the presence of atypical responses to sensory stimuli. In this study, we investigated if high functioning autistic patients had abnormalities in the blink reflex and the startle reaction to auditory or somatosensory stimuli. Fourteen patients aged between 7 and 16 years were included in the study. We found a longer latency of the blink reflex, an increased duration and amplitude of the auditory startle reaction and a lower presence rate of the somatosensorial startle reaction in autistic patients. To better define the sensorial characteristics of the disease could improve the therapeutic management of children with autism spectrum disorder.

  14. Perinatal exposure to the selective serotonin reuptake inhibitor citalopram alters spatial learning and memory, anxiety, depression, and startle in Sprague-Dawley rats.

    PubMed

    Sprowles, Jenna L N; Hufgard, Jillian R; Gutierrez, Arnold; Bailey, Rebecca A; Jablonski, Sarah A; Williams, Michael T; Vorhees, Charles V

    2016-11-01

    Selective serotonin reuptake inhibitors (SSRIs) block the serotonin (5-HT) reuptake transporter (SERT) and increase synaptic 5-HT. 5-HT is also important in brain development; hence when SSRIs are taken during pregnancy there exists the potential for these drugs to affect CNS ontogeny. Prenatal SSRI exposure has been associated with an increased prevalence of autism spectrum disorder (ASD), and peripheral 5-HT is elevated in some ASD patients. Perinatal SSRI exposure in rodents has been associated with increased depression and anxiety-like behavior, decreased sociability, and impaired learning in the offspring, behaviors often seen in ASD. The present study investigated whether perinatal exposure to citalopram causes persistent neurobehavioral effects. Gravid Sprague-Dawley rats were assigned to two groups and subcutaneously injected twice per day with citalopram (10mg/kg; Cit) or saline (Sal) 6h apart on embryonic day (E)6-21, and then drug was given directly to the pups after delivery from postnatal day (P)1-20. Starting on P60, one male/female from each litter was tested in the Cincinnati water maze (CWM) and open-field before and after MK-801. A second pair from each litter was tested in the Morris water maze (MWM) and open-field before and after (+)-amphetamine. A third pair was tested as follows: elevated zero-maze, open-field, marble burying, prepulse inhibition of acoustic startle, social preference, and forced swim. Cit-exposed rats were impaired in the MWM during acquisition and probe, but not during reversal, shift, or cued trials. Cit-exposed rats also showed increased marble burying, decreased time in the center of the open-field, decreased latency to immobility in forced swim, and increased acoustic startle across prepulse intensities with no effects on CWM. The results are consistent with citalopram inducing several ASD-like effects. The findings add to concerns about use of SSRIs during pregnancy. Further research on different classes of

  15. Effects of brain-derived and glial cell line-derived neurotrophic factors on startle response and disrupted prepulse inhibition in mice of DBA/2J inbred strain.

    PubMed

    Naumenko, Vladimir S; Bazovkina, Daria V; Morozova, Maryana V; Popova, Nina K

    2013-08-29

    Prepulse inhibition (PPI), the reduction in acoustic startle reflex when it is preceded by weak prepulse stimuli, is a measure of critical to normal brain functioning sensorimotor gating. PPI deficit was shown in a variety of psychiatric disorders including schizophrenia, and in DBA/2J mouse strain. In the current study, we examined the effects of brain-derived (BDNF) and glial cell line-derived (GDNF) neurotrophic factors on acoustic startle response and PPI in DBA/2J mice. It was found that BDNF (300 ng, i.c.v.) significantly increased amplitude of startle response and restored disrupted PPI in 7 days after acute administration. GDNF (800 ng, i.c.v.) did not produce significant alteration neither in amplitude of startle response nor in PPI in DBA/2J mice. The reversal effect of BDNF on PPI deficit was unusually long-lasting: significant increase in PPI was found 1.5 months after single acute BDNF administration. Long-term ameliorative effect BDNF on disrupted PPI suggested the implication of epigenetic mechanism in BDNF action on neurogenesis. BDNF rather than GDNF could be a perspective drug for the treatment of sensorimotor gating impairments.

  16. Fast contactless vibrating structure characterization using real time field programmable gate array-based digital signal processing: demonstrations with a passive wireless acoustic delay line probe and vision.

    PubMed

    Goavec-Mérou, G; Chrétien, N; Friedt, J-M; Sandoz, P; Martin, G; Lenczner, M; Ballandras, S

    2014-01-01

    Vibrating mechanical structure characterization is demonstrated using contactless techniques best suited for mobile and rotating equipments. Fast measurement rates are achieved using Field Programmable Gate Array (FPGA) devices as real-time digital signal processors. Two kinds of algorithms are implemented on FPGA and experimentally validated in the case of the vibrating tuning fork. A first application concerns in-plane displacement detection by vision with sampling rates above 10 kHz, thus reaching frequency ranges above the audio range. A second demonstration concerns pulsed-RADAR cooperative target phase detection and is applied to radiofrequency acoustic transducers used as passive wireless strain gauges. In this case, the 250 ksamples/s refresh rate achieved is only limited by the acoustic sensor design but not by the detection bandwidth. These realizations illustrate the efficiency, interest, and potentialities of FPGA-based real-time digital signal processing for the contactless interrogation of passive embedded probes with high refresh rates.

  17. Fast contactless vibrating structure characterization using real time field programmable gate array-based digital signal processing: Demonstrations with a passive wireless acoustic delay line probe and vision

    NASA Astrophysics Data System (ADS)

    Goavec-Mérou, G.; Chrétien, N.; Friedt, J.-M.; Sandoz, P.; Martin, G.; Lenczner, M.; Ballandras, S.

    2014-01-01

    Vibrating mechanical structure characterization is demonstrated using contactless techniques best suited for mobile and rotating equipments. Fast measurement rates are achieved using Field Programmable Gate Array (FPGA) devices as real-time digital signal processors. Two kinds of algorithms are implemented on FPGA and experimentally validated in the case of the vibrating tuning fork. A first application concerns in-plane displacement detection by vision with sampling rates above 10 kHz, thus reaching frequency ranges above the audio range. A second demonstration concerns pulsed-RADAR cooperative target phase detection and is applied to radiofrequency acoustic transducers used as passive wireless strain gauges. In this case, the 250 ksamples/s refresh rate achieved is only limited by the acoustic sensor design but not by the detection bandwidth. These realizations illustrate the efficiency, interest, and potentialities of FPGA-based real-time digital signal processing for the contactless interrogation of passive embedded probes with high refresh rates.

  18. Reheating the universe once more: the dissipation of acoustic waves as a novel probe of primordial inhomogeneities on even smaller scales.

    PubMed

    Nakama, Tomohiro; Suyama, Teruaki; Yokoyama, Jun'ichi

    2014-08-08

    We provide a simple but robust bound on the primordial curvature perturbation in the range 10(4)  Mpc(-1)acoustic oscillations by the Silk damping after primordial nucleosynthesis but before the redshift z∼2×10(6) and reheat the photon bath without invoking cosmic microwave background distortions. This acoustic reheating results in the decrease of the baryon-photon ratio. By combining independent measurements probing the nucleosynthesis era and around the recombination epoch, we find an upper bound on the amplitude of the curvature perturbation over the above wave number range as P(ζ)<0.06. Implications for supermassive black holes are also discussed.

  19. Role of bed nucleus of the stria terminalis and amygdala AMPA receptors in the development and expression of context conditioning and sensitization of startle by prior shock

    PubMed Central

    Davis, Michael

    2013-01-01

    A core symptom of post-traumatic stress disorder is hyper-arousal—manifest in part by increases in the amplitude of the acoustic startle reflex. Gewirtz et al. (Prog Neuropsychopharmacol Biol Psychiatry 22:625–648, 1998) found that, in rats, persistent shock-induced startle increases were prevented by pre-test electrolytic lesions of the bed nucleus of the stria terminalis (BNST). We used reversible inactivation to determine if similar effects reflect actions on (a) BNST neurons themselves versus fibers-of-passage, (b) the development versus expression of such increases, and (c) associative fear versus non-associative sensitization. Twenty-four hours after the last of three shock sessions, startle was markedly enhanced when rats were tested in a non-shock context. These increases decayed over the course of several days. Decay was unaffected by context exposure, and elevated startle was restored when rats were tested for the first time in the original shock context. Thus, both associative and non-associative components could be measured under different conditions. Pre-test intra-BNST infusions of the AMPA receptor antagonist NBQX (3 μg/side) blocked the non-associative (as did infusions into the basolateral amygdala) but not the associative component, whereas pre-shock infusions disrupted both. NBQX did not affect baseline startle or shock reactivity. These results indicate that AMPA receptors in or very near to the BNST are critical for the expression and development of non-associative shock-induced startle sensitization, and also for context fear conditioning, but not context fear expression. More generally, they suggest that treatments targeting the BNST may be clinically useful for treating trauma-related hyper-arousal and perhaps for retarding its development. PMID:23934654

  20. Variants near CCK receptors are associated with electrophysiological responses to prepulse startle stimuli in a Mexican American cohort

    PubMed Central

    Norden-Krichmar, Trina M.; Gizer, Ian R.; Phillips, Evelyn; Wilhelmsen, Kirk C.; Schork, Nicholas J.; Ehlers, Cindy L.

    2016-01-01

    Neurophysiological measurements of the response to prepulse and startle stimuli have been suggested to represent an important endophenotype for both substance dependence and other select psychiatric disorders. We have previously shown, in young adult Mexican Americans (MA), that presentation of a short delay acoustic prepulse, prior to the startle stimuli can elicit a late negative component at about 400 msec (N4S), in the event-related potential (ERP), recorded from frontal cortical areas. In the present study we investigated whether genetic factors associated with this endophenotype could be identified. The study included 420 (age 18 – 30 years) MA men (n=170) and women (n=250). DNA was genotyped using an Affymetrix Axiom Exome1A chip. An association analysis revealed that the CCKAR and CCKBR (cholecystokinin A and B receptor) genes each had a nearby variant that showed suggestive significance with the amplitude of the N4S component to prepulse stimuli. The neurotransmitter cholecystokinin (CCK), along with its receptors, CCKAR and CCKBR, have been previously associated with psychiatric disorders, suggesting that variants near these genes may play a role in the prepulse/startle response in this cohort. PMID:26608796

  1. Use of acoustic wave travel-time measurements to probe the near-surface layers of the Sun

    NASA Technical Reports Server (NTRS)

    Jefferies, S. M.; Osaki, Y.; Shibahashi, H.; Duvall, T. L., Jr.; Harvey, J. W.; Pomerantz, M. A.

    1994-01-01

    The variation of solar p-mode travel times with cyclic frequency nu is shown to provide information on both the radial variation of the acoustic potential and the depth of the effective source of the oscillations. Observed travel-time data for waves with frequency lower than the acoustic cutoff frequency for the solar atmosphere (approximately equals 5.5 mHz) are inverted to yield the local acoustic cutoff frequency nu(sub c) as a function of depth in the outer convection zone and lower atmosphere of the Sun. The data for waves with nu greater than 5.5 mHz are used to show that the source of the p-mode oscillations lies approximately 100 km beneath the base of the photosphere. This depth is deeper than that determined using a standard mixing-length calculation.

  2. Motivated attention and prepulse inhibition of startle in rats: using conditioned reinforcers as prepulses.

    PubMed

    Baschnagel, Joseph S; Hawk, Larry W; Colder, Craig R; Richards, Jerry B

    2007-12-01

    In humans, prepulse inhibition (PPI) of startle is greater during attended prestimuli than it is during ignored prestimuli, whereas in rats, most work has focused on passive PPI, which does not require attention. In the work described in this article, researchers developed a paradigm to assess attentional modification of PPI in rats using motivationally salient prepulses. Water-deprived rats were either conditioned to attend to a conditioned stimulus (CS; 1-s, 7-dB increase in white noise) paired with water (CS(+) group), or they received uncorrelated presentations of white noise and water (CS0 group). After 10 conditioning sessions, startle probes (50 ms, 115 dB) were introduced, with the CS serving as a continuous prepulse. Three experiments examined PPI across a range of prepulse intensities (4-10 dB) and stimulus onset asynchronies (SOAs; 30-960 ms). PPI was consistently reduced in the CS(+) group, particularly with a 10-dB prepulse and a 60-ms SOA. Thus, PPI in rats differed between attended and ignored prestimuli, but the effect was reversed in the results of research with humans. A fourth study eliminated the group difference by reversing the CS-water contingency. Methodological and motivational hypotheses regarding the current findings are discussed.

  3. A new system for the amplification of biological signals: RecA and complimentary single strand DNA probes on a leaky surface acoustic wave biosensor.

    PubMed

    Zhang, Liqun; Wang, Yunxia; Chen, Ming; Luo, Yang; Deng, Kun; Chen, Dong; Fu, Weiling

    2014-10-15

    This research describes a new amplification signals system of the leaky surface acoustic wave (LSAW) bis-peptide nucleic acid (bis-PNA) biosensor for the simple, sensitive and rapid detection of the target double-stranded DNA (dsDNA). The system consists of a RecA protein-coated complementary single-stranded DNA (cssDNA) probe complex that amplifies the biological signal to improve the sensitivity of the biosensor. The bis-PNA probe for detecting HPV was first immobilized on a gold surface membrane of the detection channel. After the probe was completely hybridized with the corresponding target DNA, different concentrations of the "RecA protein-complementary single strand DNA probe" were added to react with the bis-PNA/dsDNA complex. The phase shift of the LSAW biosensors, which was measured and found to be most significant when the RecA protein was 45 μg/mL and the ATPγS was 2.5 mmol/L. Compared with other concentrations (P<0.01) of RecA and ATPγS, the value of the phase shift was (11.74 ± 1.03) degrees and the ratio of the phase shift and hybridization time clearly outperformed that of the other concentrations. Compared to the direct hybridization of the bis-PNA probe and the target DNA sequence, the sensitivity was effectively improved and the detection time was significantly shortened. PNA binding adjacent to the area of the target sequence homologous to the probe significantly increased the yield of the hybridization reaction between the PNA/dsDNA complex and the RecA protein-coated cssDNA probe. In this condition, the phase shift was significantly obvious and the detection time was significantly shortened. In conclusion, the combination of the RecA protein-coated cssDNA probe and the LSAW bis-PNA biosensor provides sensitivity and simple and rapid detection of clinical trace pathogenic microorganisms.

  4. Startle disease or hyperekplexia: further delineation of the syndrome.

    PubMed

    Andermann, F; Keene, D L; Andermann, E; Quesney, L F

    1980-12-01

    Startle disease is an autosomal dominant disorder with two phenotypic expressions. In the major form, there is hypertonia in infancy, and later an insecure gait. The patients have falling attacks without unconsciousness and in these, they are often injured or suffer concussions. Episodes of shaking of the limbs lasting for several minutes and resembling generalized clonus or repetitive myoclonus occur. These are most often nocturnal and are also unaccompanied by loss of consciousness. the patients are hyperreflexic and show an increased incidence of associated neurological and electroencephalographic abnormalities. The minor form of startle disease is only manifested by excessive startle and this is inconstant. In infancy it is brought out by febrile illness and in adult life by emotional stress. Gastaut and Villeneuve postulated the existence of a sporadic form of hyperekplexia different from the disorder described by Suhren et al. Review of their report and comparison with the cases of Suhren et al, and our own patients leads us to believe that the sporadic and familial forms of startle disease are the same. The disorder is rare, probably misdiagnosed initially as spastic quadriplegia, and later as epilepsy. Clonazepam appears to be the treatment of choice and its effect is sustained.

  5. The startle response and toxicology: Methods, use and interpretation.

    EPA Science Inventory

    The startle response (SR) is a sensory-evoked motor reflex that has been used successfully in toxicology for decades. Advantages of this procedure include: rapidly objective measurement of a defined neural circuit, measurement of habituation of the response, and a high potential ...

  6. Eye Blink Startle Responses in Behaviorally Inhibited and Uninhibited Children

    ERIC Educational Resources Information Center

    van Brakel, Anna M. L.; Muris, Peter; Derks, Wendy

    2006-01-01

    The present study examined the startle reflex as a physiological marker of behavioral inhibition. Participants were 7 to 12-year-old children who had been previously identified as inhibited or uninhibited as part of an ongoing longitudinal study on the role of behavioral inhibition in the development of anxiety disorders. Analysis of their scores…

  7. Emotion-modulated startle in psychopathy: Clarifying familiar effects

    PubMed Central

    Baskin-Sommers, Arielle R.; Curtin, John J.; Newman, Joseph P.

    2012-01-01

    The behavior of psychopathic individuals is thought to reflect a core fear deficit that prevents these individuals from appreciating the consequences of their choices and actions. However, growing evidence suggests that psychopathy-related emotion deficits are moderated by attention and, thus, may not reflect a reduced capacity for emotion responding. The present study attempts to reconcile this attention perspective with one of the most cited findings in psychopathy, which reports emotion-modulated startle deficits among psychopathic individuals during picture viewing. In this study, we evaluate the potential effects of a putative attention bottleneck on the emotion processing of psychopathic offenders during picture viewing by manipulating picture familiarity and examining emotion-modulated startle and late positive potential (LPP). As predicted, psychopathic individuals displayed the classic deficit in emotion-modulated startle during novel pictures, but they showed no deficit in emotion-modulated startle during familiar pictures. Conversely, results for LPP responses revealed psychopathy-related differences during familiar pictures and no psychopathy-related differences during novel pictures. Important differences related to the two Factors of psychopathy are also discussed. Overall, the results of this study not only highlight the differential importance of perceptual load on emotion processing in psychopathy, but also raise interesting questions about the varied effects of attention on psychopathy-related emotion deficits. PMID:23356218

  8. Startle responses in Parkinson patients during human gait.

    PubMed

    Nieuwenhuijzen, P H J A; Horstink, M W; Bloem, B R; Duysens, J

    2006-05-01

    Falls frequently occur in patients with Parkinson's disease (Bloem et al. 2001). One potential source for such falls during walking might be caused by the reaction to loud noises. In normal subjects startle reactions are well integrated in the locomotor activity (Nieuwenhuijzen et al. 2000), but whether this is also achieved in Parkinson patients is unknown. Therefore, in the present study, the startle response during walking was studied in eight patients with Parkinson's disease and in eight healthy subjects. To examine how startle reactions are incorporated in an ongoing gait pattern of these patients, unexpected auditory stimuli were presented in six phases of the step cycle during walking on a treadmill. For both legs electromyographic activity was recorded from biceps femoris and tibialis anterior. In addition, we measured the stance and swing phases of both legs, along with the knee angles of both legs and the left ankle angle. In all subjects and all muscles, responses were detected. The pattern of the responses, latency, duration, and phase-dependent modulation was similar in both groups. However, the mean response amplitude was larger in patients due to a smaller habituation rate. No correlation was found between the degree of habituation and disease severity. Moreover, a decreased habituation was already observed in mildly affected patients, indicating that habituation of the startle response is a sensitive measure of Parkinson's disease. The results complement the earlier findings of reduced habituation of blink responses in Parkinson's disease. With respect to behavioral changes in healthy subjects we observed that startle stimuli induced a shortening of the step cycle and a decrease in range of motion. In the patient group, less shortening of the subsequent step cycle and no decrease in range of motion of the knee and ankle was seen. It is argued that the observed changes might contribute to the high incidence of falls in patients with Parkinson

  9. Probing the colloidal properties of skim milk using acoustic and electroacoustic spectroscopy. Effect of concentration, heating and acidification.

    PubMed

    Gülseren, Ibrahim; Alexander, Marcela; Corredig, Milena

    2010-11-15

    In colloidal systems physical-chemical changes are often a function of volume fraction and sample dilutions are critical. While most methods to characterize colloidal particles either require dilution or some disruption, acoustic spectroscopy can be performed in situ, without dilution. Objective of this work was to determine the effects of concentration, heating and acidification on the acoustic and electroacoustic properties of casein micelles in skim milk. The ultrasonic attenuation of skim milk increased with concentration of milk and frequency, and the average size of the colloidal particles calculated from the frequency dependence of attenuation was about 0.15 μm for both unheated and heated milk. When milk was concentrated by ultrafiltration, at 3× and 4× concentration (based on volume reduction), the calculated size deviated from that derived in undiluted or mildly concentrated milk, most likely because of increased particle-particle interactions. Electroacoustic measurements revealed a constant dynamic mobility of the particles in undiluted and concentrated milk, while lower mobilities were observed for milk diluted in permeate. The ζ-potential measured was significantly higher than the values measured using dynamic light scattering, with a value of -45.8 mV for casein micelles in unheated milk. With acidification, the ζ-potential decreased monotonically. Heating profoundly affected the change in charge with pH of the micelles, and it was concluded that the interaction of casein micelles with the whey proteins increased the surface charge of the casein micelles.

  10. Line-focus probe excitation of Scholte acoustic waves at the liquid-loaded surfaces of periodic structures

    SciTech Connect

    Every, A.G.; Vines, R.E.; Wolfe, J.P.

    1999-10-01

    A model is introduced to explain our observation of Scholte-like ultrasonic waves traveling at the water-loaded surfaces of solids with periodically varying properties. The observations pertain to two two-dimensional superlattices: a laminated solid of alternating 0.5-mm-thick layers of aluminum and a polymer, and a hexagonal array of polymer rods of lattice spacing 1 mm in an aluminum matrix. The surface waves are generated and detected by line focus acoustic lenses aligned parallel to each other, and separated by varying distances. The acoustic fields of these lenses may be considered a superposition of plain bulk waves with wave normals contained within the angular apertures of the lenses. For homogeneous solids, phase matching constraints do not allow the Scholte wave to be coupled into with an experimental configuration of this type. This is not true for a spatially periodic solid, where coupling between bulk waves and the Scholte surface wave takes place through Umklapp processes involving a change in the wave-vector component parallel to the surface by a reciprocal lattice vector. In the experiments, the source pulse is broadband, extending up to about 6 MHz, whereas the spectrum of the observed Scholte wave is peaked at around 4 and 4.5 MHz for the layered solid and hexagonal lattice, respectively. We attribute this to a resonance in the surface response of the solid, possibly associated with a critical point in the dispersion relation of the superlattice. On rotating the solid about its surface normal, the Scholte wave displays dramatic variation in phase arrival time and, to a lesser extent, also group arrival time. This variation is well accounted for by our model. {copyright} {ital 1999} {ital The American Physical Society}

  11. Startle auditory stimuli enhance the performance of fast dynamic contractions.

    PubMed

    Fernandez-Del-Olmo, Miguel; Río-Rodríguez, Dan; Iglesias-Soler, Eliseo; Acero, Rafael M

    2014-01-01

    Fast reaction times and the ability to develop a high rate of force development (RFD) are crucial for sports performance. However, little is known regarding the relationship between these parameters. The aim of this study was to investigate the effects of auditory stimuli of different intensities on the performance of a concentric bench-press exercise. Concentric bench-presses were performed by thirteen trained subjects in response to three different conditions: a visual stimulus (VS); a visual stimulus accompanied by a non-startle auditory stimulus (AS); and a visual stimulus accompanied by a startle auditory stimulus (SS). Peak RFD, peak velocity, onset movement, movement duration and electromyography from pectoralis and tricep muscles were recorded. The SS condition induced an increase in the RFD and peak velocity and a reduction in the movement onset and duration, in comparison with the VS and AS condition. The onset activation of the pectoralis and tricep muscles was shorter for the SS than for the VS and AS conditions. These findings point out to specific enhancement effects of loud auditory stimulation on the rate of force development. This is of relevance since startle stimuli could be used to explore neural adaptations to resistance training.

  12. Startle Auditory Stimuli Enhance the Performance of Fast Dynamic Contractions

    PubMed Central

    Fernandez-Del-Olmo, Miguel; Río-Rodríguez, Dan; Iglesias-Soler, Eliseo; Acero, Rafael M.

    2014-01-01

    Fast reaction times and the ability to develop a high rate of force development (RFD) are crucial for sports performance. However, little is known regarding the relationship between these parameters. The aim of this study was to investigate the effects of auditory stimuli of different intensities on the performance of a concentric bench-press exercise. Concentric bench-presses were performed by thirteen trained subjects in response to three different conditions: a visual stimulus (VS); a visual stimulus accompanied by a non-startle auditory stimulus (AS); and a visual stimulus accompanied by a startle auditory stimulus (SS). Peak RFD, peak velocity, onset movement, movement duration and electromyography from pectoralis and tricep muscles were recorded. The SS condition induced an increase in the RFD and peak velocity and a reduction in the movement onset and duration, in comparison with the VS and AS condition. The onset activation of the pectoralis and tricep muscles was shorter for the SS than for the VS and AS conditions. These findings point out to specific enhancement effects of loud auditory stimulation on the rate of force development. This is of relevance since startle stimuli could be used to explore neural adaptations to resistance training. PMID:24489967

  13. Developmental investigation of fear-potentiated startle across puberty.

    PubMed

    Schmitz, Anja; Grillon, Christian; Avenevoli, Shelli; Cui, Lihong; Merikangas, Kathleen R

    2014-03-01

    The goal of this study was to examine the association between affective development, puberty, and gender using the startle reflex as a marker of defensive mechanisms. Thirty-one male and thirty-five female adolescents aged ten to thirteen participated in a prospective study with up to five assessments. Longitudinal analyses revealed a significant effect of sex, with girls showing stronger fear-potentiation at all pubertal stages. Post hoc tests revealed that fear-potentiation increased in girls but not boys over the course of puberty. Furthermore, baseline startle decreased over the course of puberty. Because age was included as a covariate in all analyses, the puberty effect cannot be accounted for by age. To the best of our knowledge, this study provides the first evidence for a significant increase in fear-potentiated startle across the pubertal transition. Attribution of these changes to pubertal status rather than age has important implications for our understanding of the neurobiology of anxiety and affect regulation.

  14. Corpus callosotomy in a patient with startle epilepsy.

    PubMed

    Gómez, Nicolás Garófalo; Hamad, Ana Paula; Marinho, Murilo; Tavares, Igor M; Carrete, Henrique; Caboclo, Luís Otávio; Yacubian, Elza Márcia; Centeno, Ricardo

    2013-03-01

    Startle epilepsy is a syndrome of reflex epilepsy in which the seizures are precipitated by a sudden and surprising, usually auditory, stimulus. We describe herein a girl who had been suffering with startle-induced seizures since 2 years of age. She had focal, tonic and tonic-clonic seizures, refractory to antiepileptic treatment. Daily tonic seizures led to very frequent falls and morbidity. Neurologically, she had no deficit. Interictal EEG showed slow waves and epileptiform discharges in central and fronto-central regions. Video-polygraphic recordings of seizures, triggered by stimuli, showed generalised symmetric tonic posturing with ictal EEG, characterised by an abrupt and diffuse electrodecremental pattern of fast activity, followed by alpha-theta rhythm superimposed by epileptic discharges predominantly over the vertex and anterior regions. Magnetic resonance imaging showed no abnormalities. Corpus callosotomy was performed when the patient was 17. Since surgery, the patient (one year follow-up) has remained seizure-free. Corpus callosotomy may be considered in patients with startle epilepsy and tonic seizures, in the absence of focal lesions amenable to surgery. [Published with video sequences].

  15. Changes in trauma-potentiated startle with treatment of posttraumatic stress disorder in combat Veterans.

    PubMed

    Robison-Andrew, E Jenna; Duval, Elizabeth R; Nelson, C Beau; Echiverri-Cohen, Aileen; Giardino, Nicholas; Defever, Andrew; Norrholm, Seth D; Jovanovic, Tanja; Rothbaum, Barbara O; Liberzon, Israel; Rauch, Sheila A M

    2014-05-01

    Emotional Processing Theory proposes that habituation to trauma-related stimuli is an essential component of PTSD treatment. However, the mechanisms underlying treatment-related habituation are not well understood. We examined one psychophysiological measure that holds potential for elucidating the biological processes involved in treatment response: trauma-potentiated startle response. Seventeen OEF/OIF combat Veterans participated in the study and completed three assessments using a trauma-potentiated startle paradigm over PTSD treatment. Results revealed different patterns of trauma-potentiated startle across treatment for responders and nonresponders, but no differences in within task habituation. Responders showed an increase followed by a decrease in trauma-potentiated startle, whereas nonresponders showed a relatively flat response profile. Results suggested that PTSD patients who engage with emotional content as demonstrated by greater startle reactivity may be more likely to respond to PTSD treatment. Furthermore, trauma-potentiated startle shows promise as an objective measure of psychophysiological responses involved in PTSD recovery.

  16. The neonatal acoustic reflex.

    PubMed

    Weatherby, L A; Bennett, M J

    1980-01-01

    Probe tones from 220 Hz to 2 000 Hz were used to measure the static and dynamic acoustic impedance of 44 neonates. Acoustic reflex thresholds to broad band noise were obtained from every neonate tested when employing the higher frequency probe tones. The reflex threshold levels measured are similar to those of adults. The static impedance values are discussed to give a possible explanation of why reflex thresholds cannot be detected using conventional 220 Hz impedance bridges.

  17. Genetic Control of Startle Behavior in Medaka Fish

    PubMed Central

    Tsuboko, Satomi; Kimura, Tetsuaki; Shinya, Minori; Suehiro, Yuji; Okuyama, Teruhiro; Shimada, Atsuko; Takeda, Hiroyuki; Naruse, Kiyoshi; Kubo, Takeo; Takeuchi, Hideaki

    2014-01-01

    Genetic polymorphisms are thought to generate intraspecific behavioral diversities, both within and among populations. The mechanisms underlying genetic control of behavioral properties, however, remain unclear in wild-type vertebrates, including humans. To explore this issue, we used diverse inbred strains of medaka fish (Oryzias latipes) established from the same and different local populations. Medaka exhibit a startle response to a visual stimulus (extinction of illumination) by rapidly bending their bodies (C-start) 20-ms after the stimulus presentation. We measured the rates of the response to repeated stimuli (1-s interval, 40 times) among four inbred strains, HNI-I, HNI-II, HO5, and Hd-rR-II1, and quantified two properties of the startle response: sensitivity (response rate to the first stimulus) and attenuation of the response probability with repeated stimulus presentation. Among the four strains, the greatest differences in these properties were detected between HNI-II and Hd-rR-II1. HNI-II exhibited high sensitivity (approximately 80%) and no attenuation, while Hd-rR-II1 exhibited low sensitivity (approximately 50%) and almost complete attenuation after only five stimulus presentations. Our findings suggested behavioral diversity of the startle response within a local population as well as among different populations. Linkage analysis with F2 progeny between HNI-II and Hd-rR-II1 detected quantitative trait loci (QTL) highly related to attenuation, but not to sensitivity, with a maximum logarithm of odds score of 11.82 on linkage group 16. The three genotypes (homozygous for HNI-II and Hd-rR-II1 alleles, and heterozygous) at the marker nearest the QTL correlated with attenuation. Our findings are the first to suggest that a single genomic region might be sufficient to generate individual differences in startle behavior between wild-type strains. Further identification of genetic polymorphisms that define the behavioral trait will contribute to our

  18. Mutations in the human GlyT2 gene define a presynaptic component of human startle disease

    PubMed Central

    Rees, Mark I.; Harvey, Kirsten; Pearce, Brian R.; Chung, Seo-Kyung; Duguid, Ian C.; Thomas, Philip; Beatty, Sarah; Graham, Gail E.; Armstrong, Linlea; Shiang, Rita; Abbott, Kim J.; Zuberi, Sameer M.; Stephenson, John B.P.; Owen, Michael J.; Tijssen, Marina A.J.; van den Maagdenberg, Arn M.J.M.; Smart, Trevor G.; Supplisson, Stéphane; Harvey, Robert J.

    2011-01-01

    Hyperekplexia is a human neurological disorder characterized by an excessive startle response and is typically caused by missense and nonsense mutations in the gene encoding the inhibitory glycine receptor (GlyR) α1 subunit (GLRA1)1-3. Genetic heterogeneity has been confirmed in isolated sporadic cases with mutations in other postsynaptic glycinergic proteins including the GlyR β subunit (GLRB)4, gephyrin (GPHN)5 and RhoGEF collybistin (ARHGEF9)6. However, many sporadic patients diagnosed with hyperekplexia do not carry mutations in these genes2-7. Here we reveal that missense, nonsense and frameshift mutations in the presynaptic glycine transporter 2 (GlyT2) gene (SLC6A5)8 also cause hyperekplexia. Patients harbouring mutations in SLC6A5 presented with hypertonia, an exaggerated startle response to tactile or acoustic stimuli, and life-threatening neonatal apnoea episodes. GlyT2 mutations result in defective subcellular localisation and/or decreased glycine uptake, with selected mutations affecting predicted glycine and Na+ binding sites. Our results demonstrate that SLC6A5 is a major gene for hyperekplexia and define the first neurological disorder linked to mutations in a Na+/Cl−-dependent transporter for a classical fast neurotransmitter. By analogy, we suggest that in other human disorders where defects in postsynaptic receptors have been identified, similar symptoms could result from defects in the cognate presynaptic neurotransmitter transporter. PMID:16751771

  19. Stochastic dislocation kinetics and fractal structures in deforming metals probed by acoustic emission and surface topography measurements

    SciTech Connect

    Vinogradov, A.; Yasnikov, I. S.; Estrin, Y.

    2014-06-21

    We demonstrate that the fractal dimension (FD) of the dislocation population in a deforming material is an important quantitative characteristic of the evolution of the dislocation structure. Thus, we show that peaking of FD signifies a nearing loss of uniformity of plastic flow and the onset of strain localization. Two techniques were employed to determine FD: (i) inspection of surface morphology of the deforming crystal by white light interferometry and (ii) monitoring of acoustic emission (AE) during uniaxial tensile deformation. A connection between the AE characteristics and the fractal dimension determined from surface topography measurements was established. As a common platform for the two methods, the dislocation density evolution in the bulk was used. The relations found made it possible to identify the occurrence of a peak in the median frequency of AE as a harbinger of plastic instability leading to necking. It is suggested that access to the fractal dimension provided by AE measurements and by surface topography analysis makes these techniques important tools for monitoring the evolution of the dislocation structure during plastic deformation—both as stand-alone methods and especially when used in tandem.

  20. Probing large-scale structure with large samples of X-ray selected AGN. I. Baryonic acoustic oscillations

    NASA Astrophysics Data System (ADS)

    Hütsi, Gert; Gilfanov, Marat; Kolodzig, Alexander; Sunyaev, Rashid

    2014-12-01

    We investigate the potential of large X-ray-selected AGN samples for detecting baryonic acoustic oscillations (BAO). Though AGN selection in X-ray band is very clean and efficient, it does not provide redshift information, and thus needs to be complemented with an optical follow-up. The main focus of this study is (i) to find the requirements needed for the quality of the optical follow-up and (ii) to formulate the optimal strategy of the X-ray survey, in order to detect the BAO. We demonstrate that redshift accuracy of σ0 = 10-2 at z = 1 and the catastrophic failure rate of ffail ≲ 30% are sufficient for a reliable detection of BAO in future X-ray surveys. Spectroscopic quality redshifts (σ0 = 10-3 and ffail ~ 0) will boost the confidence level of the BAO detection by a factor of ~2. For meaningful detection of BAO, X-ray surveys of moderate depth of Flim ~ few 10-15 erg s-1/cm2 covering sky area from a few hundred to ~ten thousand square degrees are required. The optimal strategy for the BAO detection does not necessarily require full sky coverage. For example, in a 1000 day-long survey by an eROSITA type telescope, an optimal strategy would be to survey a sky area of ~9000 deg2, yielding a ~16σ BAO detection. A similar detection will be achieved by ATHENA+ or WFXT class telescopes in a survey with a duration of 100 days, covering a similar sky area. XMM-Newton can achieve a marginal BAO detection in a 100-day survey covering ~400 deg2. These surveys would demand a moderate-to-high cost in terms the optical follow-ups, requiring determination of redshifts of ~105 (XMM-Newton) to ~3 × 106 objects (eROSITA, ATHENA+, and WFXT) in these sky areas.

  1. Hypnotizability and Placebo Analgesia in Waking and Hypnosis as Modulators of Auditory Startle Responses in Healthy Women: An ERP Study

    PubMed Central

    De Pascalis, Vilfredo; Scacchia, Paolo

    2016-01-01

    We evaluated the influence of hypnotizability, pain expectation, placebo analgesia in waking and hypnosis on tonic pain relief. We also investigated how placebo analgesia affects somatic responses (eye blink) and N100 and P200 waves of event-related potentials (ERPs) elicited by auditory startle probes. Although expectation plays an important role in placebo and hypnotic analgesia, the neural mechanisms underlying these treatments are still poorly understood. We used the cold cup test (CCT) to induce tonic pain in 53 healthy women. Placebo analgesia was initially produced by manipulation, in which the intensity of pain induced by the CCT was surreptitiously reduced after the administration of a sham analgesic cream. Participants were then tested in waking and hypnosis under three treatments: (1) resting (Baseline); (2) CCT-alone (Pain); and (3) CCT plus placebo cream for pain relief (Placebo). For each painful treatment, we assessed pain and distress ratings, eye blink responses, N100 and P200 amplitudes. We used LORETA analysis of N100 and P200 waves, as elicited by auditory startle, to identify cortical regions sensitive to pain reduction through placebo and hypnotic analgesia. Higher pain expectation was associated with higher pain reductions. In highly hypnotizable participants placebo treatment produced significant reductions of pain and distress perception in both waking and hypnosis condition. P200 wave, during placebo analgesia, was larger in the frontal left hemisphere while placebo analgesia, during hypnosis, involved the activity of the left hemisphere including the occipital region. These findings demonstrate that hypnosis and placebo analgesia are different processes of top-down regulation. Pain reduction was associated with larger EMG startle amplitudes, N100 and P200 responses, and enhanced activity within the frontal, parietal, and anterior and posterior cingulate gyres. LORETA results showed that placebo analgesia modulated pain-responsive areas

  2. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor; Hearing loss - acoustic; Tinnitus - acoustic ... Acoustic neuromas have been linked with the genetic disorder neurofibromatosis type 2 (NF2). Acoustic neuromas are uncommon.

  3. Motor cortex inhibition induced by acoustic stimulation.

    PubMed

    Kühn, Andrea A; Sharott, Andrew; Trottenberg, Thomas; Kupsch, Andreas; Brown, Peter

    2004-09-01

    The influence of the brainstem motor system on cerebral motor areas may play an important role in motor control in health and disease. A new approach to investigate this interaction in man is combining acoustic stimulation activating the startle system with transcranial magnetic stimulation (TMS) over the motor cortex. However, it is unclear whether the inhibition of TMS responses following acoustic stimulation occurs at the level of the motor cortex through reticulo-cortical projections or subcortically, perhaps through reticulo-spinal projections. We compared the influence of acoustic stimulation on motor effects elicited by TMS over motor cortical areas to those evoked with subcortical electrical stimulation (SES) through depth electrodes in five patients treated with deep brain stimulation for Parkinson's disease. SES bypasses the motor cortex, demonstrating any interaction with acoustic stimuli at the subcortical level. EMG was recorded from the contralateral biceps brachii muscle. Acoustic stimulation was delivered binaurally through headphones and used as a conditioning stimulus at an interstimulus interval of 50 ms. When TMS was used as the test stimulus, the area and amplitude of the conditioned motor response was significantly inhibited (area: 57.5+/-12.9%, amplitude: 47.9+/-7.4%, as percentage of unconditioned response) whereas facilitation occurred with SES (area: 110.1+/-4.3%, amplitude: 116.9+/-6.9%). We conclude that a startle-evoked activation of reticulo-cortical projections transiently inhibits the motor cortex.

  4. The anthraquinone derivative emodin attenuates methamphetamine-induced hyperlocomotion and startle response in rats.

    PubMed

    Mizuno, Makoto; Kawamura, Hiroki; Ishizuka, Yuta; Sotoyama, Hidekazu; Nawa, Hiroyuki

    2010-12-01

    Abnormal signaling mediated by epidermal growth factor (EGF) or its receptor (ErbB) is implicated in the neuropathology of schizophrenia. Previously, we found that the anthraquinone derivative emodin (3-methyl-1,6,8-trihydroxyanthraquinone) inhibits ErbB1 signaling and ameliorates behavioral deficits of the schizophrenia animal model established by EGF challenge. In the present study, we assessed acute and subchronic effects of its administration on methamphetamine-triggered behavioral hyperactivation in rats. Prior subchronic administration of emodin (50mg/kg/day, 5days, p.o.) suppressed both higher acoustic startle responses and hyperlocomotion induced by acute methamphetamine challenge. In parallel, emodin also attenuated methamphetamine-induced increases in dopamine and its metabolites and decreases in serotonin and its metabolites. Emodin administered alone also had an effect on stereotypic movement but no influence on horizontal or vertical locomotor activity. In contrast to pre-treatment, post-treatment with emodin had no effect on behavioral sensitization to methamphetamine. Administration of emodin in parallel to or following repeated methamphetamine challenge failed to affect hyperlocomotion induced by methamphetamine re-challenges. These findings suggest that emodin has unique pharmacological activity, which interferes with acute methamphetamine signaling and behavior.

  5. Examining habituation of the startle reflex with the reinforcement sensitivity theory of personality.

    PubMed

    Blanch, Angel; Aluja, Anton; Blanco, Eduardo; Balada, Ferran

    2016-10-01

    The habituation of the acoustic startle reflex (ASR) was examined concerning individual differences in sensitivity to punishment (PUN) and sensitivity to reward (REW), within the general framework of the reinforcement sensitivity theory (RST) of personality. Two hypotheses derived from the RST were evaluated: the separable subsystems hypothesis and the joint subsystems hypothesis. In addition, we examined the direction of the relationship of PUN and REW with the habituation of the ASR. A habituation segment of electromyography recordings of the orbicularis oculi was assessed with an unconditional latent curve model. In accordance with the RST hypotheses, the relationship of PUN and REW on the habituation process was assessed with two conditional latent curve models. There was higher support for the separable subsystems hypothesis. In addition, PUN and REW related with the habituation trajectory of the ASR in the expected directions. Higher levels of PUN and lower levels of REW related with a slower habituation of the ASR, whereas lower levels of PUN and higher levels of REW related with a faster habituation of the ASR.

  6. Whiplash evokes descending muscle recruitment and sympathetic responses characteristic of startle

    PubMed Central

    Mang, Daniel WH; Siegmund, Gunter P; Blouin, Jean-Sébastien

    2014-01-01

    Whiplash injuries are the most common injuries following rear-end collisions. During a rear-end collision, the human muscle response consists of both a postural and a startle response that may exacerbate injury. However, most previous studies only assessed the presence of startle using data collected from the neck muscles and head/neck kinematics. The startle response also evokes a descending pattern of muscle recruitment and changes in autonomic activity. Here we examined the recruitment of axial and appendicular muscles along with autonomic responses to confirm whether these other features of a startle response were present during the first exposure to a whiplash perturbation. Ten subjects experienced a single whiplash perturbation while recording electromyography, electrocardiogram, and electrodermal responses. All subjects exhibited a descending pattern of muscle recruitment, and increasing heart rate and electrodermal responses following the collision. Our results provide further support that the startle response is a component of the response to whiplash collisions. PMID:24932015

  7. Whiplash evokes descending muscle recruitment and sympathetic responses characteristic of startle.

    PubMed

    Mang, Daniel Wh; Siegmund, Gunter P; Blouin, Jean-Sébastien

    2014-06-01

    Whiplash injuries are the most common injuries following rear-end collisions. During a rear-end collision, the human muscle response consists of both a postural and a startle response that may exacerbate injury. However, most previous studies only assessed the presence of startle using data collected from the neck muscles and head/neck kinematics. The startle response also evokes a descending pattern of muscle recruitment and changes in autonomic activity. Here we examined the recruitment of axial and appendicular muscles along with autonomic responses to confirm whether these other features of a startle response were present during the first exposure to a whiplash perturbation. Ten subjects experienced a single whiplash perturbation while recording electromyography, electrocardiogram, and electrodermal responses. All subjects exhibited a descending pattern of muscle recruitment, and increasing heart rate and electrodermal responses following the collision. Our results provide further support that the startle response is a component of the response to whiplash collisions.

  8. Chronic jet lag impairs startle-induced locomotion in Drosophila.

    PubMed

    Vaccaro, Alexandra; Birman, Serge; Klarsfeld, André

    2016-12-01

    Endogenous circadian clocks with ~24-h periodicity are found in most organisms from cyanobacteria to humans. Daylight synchronizes these clocks to solar time. In humans, shift-work and jet lag perturb clock synchronization, and such perturbations, when repeated or chronic, are strongly suspected to be detrimental to healthspan. Here we investigated locomotor aging and longevity in Drosophila melanogaster with genetically or environmentally disrupted clocks. We compared two mutations in period (per, a gene essential for circadian rhythmicity in Drosophila), after introducing them in a common reference genetic background: the arrhythmic per(01), and per(T) which displays robust short 16-h rhythms. Compared to the wild type, both per mutants showed reduced longevity and decreased startle-induced locomotion in aging flies, while spontaneous locomotor activity was not impaired. The per(01) phenotypes were generally less severe than those of per(T), suggesting that chronic jet lag is more detrimental to aging than arrhythmicity in Drosophila. Interestingly, the adjustment of environmental light-dark cycles to the endogenous rhythms of the per(T) mutant fully suppressed the acceleration in the age-related decline of startle-induced locomotion, while it accelerated this decline in wild-type flies. Overall, our results show that chronic jet lag accelerates a specific form of locomotor aging in Drosophila, and that this effect can be alleviated by environmental changes that ameliorate circadian rhythm synchronization.

  9. Reflexes Inhibited by a Prepulse: Intensity of Startle Stimulus and Prepulse Across Onset Intervals.

    PubMed

    Nishiyama, Ryoji; Iso, Hiroyuki

    2016-08-01

    Prepulse inhibition refers to the inhibition of the startle reflexes by a weak stimulus (prepulse) that precedes a strong startle stimulus (pulse). Previous findings suggest that prepulse intensity affects prepulse inhibition amplitude and that prepulse inhibition amplitudes vary across onset intervals between the prepulse and pulse. However, evidence regarding the effect of startle stimulus intensity is still inconclusive, especially due to variations between prepulse inhibition scores calculated by using percentage-type and difference-type formulas. Moreover, the combined effect of startle stimulus and prepulse intensities across onset intervals remains poorly understood. The present study investigated the combined effect as well as the influence of startle response amplitudes on the formulae used for the calculation. The results suggest that startle stimulus intensity could potentially affect results of percentage-type formulae for calculating prepulse inhibition over a wide range of lead intervals. Furthermore, the results demonstrated that a combination of strong startle stimulus intensities and weak prepulse intensities could not induce prepulse inhibition at long onset intervals (1000 ms and 2000 ms).

  10. STS-70 Discovery launch startled birds at ignition

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Startled birds scatter as the stillness of a summer morning is broken by a giant's roar. The Space Shuttle Discovery thundered into space from launch Pad 39-B at 9:41:55:078 a.m. EDT. STS-70 is the 70th Shuttle flight overall, the 21st for Discovery (OV- 103), and the fourth Shuttle flight in 1995. On board for the nearly eight-day mission are a crew of five: Commander Terence 'Tom' Hendricks; Pilot Kevin R. Kregel; and Mission Specialists Nancy Jane Currie, Donald A. Thomas and Mary Ellen Weber. The crew's primary objective is to deploy the Tracking and Data Relay Satellite-G (TDRS-G), which will join a constellation of other TDRS spacecraft already on orbit.

  11. Approach and withdrawal actions modulate the startle reflex independent of affective valence and muscular effort.

    PubMed

    Thibodeau, Ryan

    2011-07-01

    The startle reflex is modulated during processing of pleasant and unpleasant affective cues. One explanation of this finding contends that approach and withdrawal motivational processes are key to explaining the effect. Undergraduates performed arm flexion and arm extension actions shown elsewhere to reliably elicit approach and withdrawal motives, respectively. Results showed that arm extension (a withdrawal action) was associated with the largest startles, followed by a neutral control action and arm flexion (an approach action). This pattern was not attributable to the subjective pleasantness or muscular effort associated with the actions. Results support motivational priming accounts of startle reflex modulation.

  12. Development of a model of startle resulting from exposure to sonic booms

    NASA Astrophysics Data System (ADS)

    Marshall, Andrew J.

    Aircraft manufacturers believe that it is possible to create supersonic business jets that would have quieter sonic booms than those that lead to the current ban on overland commercial supersonic flight over the US. In order to assess if the impact of these "low booms" is acceptable to the public, new human subject testing must occur. In recent studies, it was found that subjects' judgments of annoyance were highly correlated to judgments of startle and were unable to be fully explained by loudness judgments alone. However, this experiment utilized earphones for playback, which was unable to reproduce low frequencies (< 25 Hz) well. Building upon this study, an additional semantic differential experiment was conducted using a sonic boom simulator for playback which could reproduce these frequency components. Results of both experiments were similar and again it was found that average startle and annoyance ratings were highly correlated and that statistics of time-varying loudness were highly correlated with subjects' responses. However, it was unclear if subjects' judgments of startle corresponded to physiological responses associated with startle. To examine if physiological responses associated with startle were evoked by the low booms, two studies were conducted; a pilot study and a repeatability study. While physiological responses associated with startle were evoked by low booms, startle responses were found to have occurred infrequently. However, subjects' judgments of startle were found to be correlated with physiological responses and to have less day-to-day and subject to-subject variance. Candidate startle models were estimated from data obtained from an experiment where subjects' judged the startle evoked by a series of low amplitude sonic booms and boom-like noises. These candidate startle models were then tested in an additional study which used a more diverse set of stimuli. It was found that a linear model consisting of the maximum long-term Moore

  13. Role of the substantia nigra pars reticulata in sensorimotor gating, measured by prepulse inhibition of startle in rats.

    PubMed

    Koch, M; Fendt, M; Kretschmer, B D

    2000-12-20

    The substantia nigra pars reticulata (SNR) is one of the major output nuclei of the basal ganglia. It connects the dorsal and ventral striatum with the thalamus, superior colliculus and pontomedullary brainstem. The SNR is therefore in a strategic position to regulate sensorimotor behavior. We here assessed the effects of SNR lesions on prepulse inhibition (PPI) of the acoustic startle response (ASR), stereotypy and locomotion in drug-free rats, as well as after systemic administration of the dopamine agonist DL-amphetamine (2 mg/kg), and the NMDA receptor antagonists dizocilpine (0.16 mg/kg) and CGP 40116 (2 mg/kg). SNR lesions reduced PPI, enhanced spontaneous sniffing and potentiated the locomotor stimulation by dizocilpine and CGP 40116. PPI was impaired by dizocilpine and CGP 40116 in controls. The ASR was enhanced in controls by dizocilpine and amphetamine. SNR lesions prevented the enhancement of the ASR by amphetamine. A second experiment tested the hypothesis that the SNR mediates PPI via a GABAergic inhibition of the startle pathway. Infusion of the GABA(B) antagonist phaclofen but not the GABA(A) antagonist picrotoxin into the caudal pontine reticular nucleus reduced PPI. Hence, lesion of the SNR reduces sensorimotor gating possibly by elimination of a nigroreticular GABAergic projection interacting with GABA(B) receptors. Moreover, destruction of the SNR enhances the motor stimulatory effects of amphetamine and of the NMDA antagonists dizocilpine and CGP 40116. We conclude that the SNR exerts a tonic GABAergic inhibition on sensorimotor behavior that is regulated by the dorsal and the ventral striatum.

  14. In Vivo Ca(2+) Imaging Reveals that Decreased Dendritic Excitability Drives Startle Habituation.

    PubMed

    Marsden, Kurt C; Granato, Michael

    2015-12-01

    Exposure to repetitive startling stimuli induces habitation, a simple form of learning. Despite its simplicity, the precise cellular mechanisms by which repeated stimulation converts a robust behavioral response to behavioral indifference are unclear. Here, we use head-restrained zebrafish larvae to monitor subcellular Ca(2+) dynamics in Mauthner neurons, the startle command neurons, during startle habituation in vivo. Using the Ca(2+) reporter GCaMP6s, we find that the amplitude of Ca(2+) signals in the lateral dendrite of the Mauthner neuron determines startle probability and that depression of this dendritic activity rather than downstream inhibition mediates glycine and N-methyl-D-aspartate (NMDA)-receptor-dependent short-term habituation. Combined, our results suggest a model for habituation learning in which increased inhibitory drive from feedforward inhibitory neurons combined with decreased excitatory input from auditory afferents decreases dendritic and Mauthner neuron excitability.

  15. Magnetomechanical Acoustic Emission - A Review

    DTIC Science & Technology

    1986-09-01

    Nickel Alloys Ferromagnetic Materials LA Acoustic Emission Barkhausen noise O-A Residual Stress ’~20 ABSTWA 7- ontinue reverse ad. Ii nedceeory and...also called magneto-acoustic emission [13], or acoustic Barkhausen effect [1]. When a ferromagnetic sample is placed in an alternating magnetic field...transducer, which should be insensitive to a magnetic field, was attached to a sample. A flux sensing coil and a Barkhausen noise (BN) probe are also

  16. Heroin reduces startle and cortisol response in opioid-maintained heroin-dependent patients.

    PubMed

    Walter, Marc; Wiesbeck, Gerhard A; Degen, Bigna; Albrich, Jürgen; Oppel, Monika; Schulz, André; Schächinger, Hartmut; Dürsteler-MacFarland, Kenneth M

    2011-01-01

    Heroin dependence (HD) is a chronic relapsing brain disorder characterized by a compulsion to seek and use heroin. Stress is seen as a key factor for heroin use. Methadone maintenance and the prescription of pharmaceutical heroin [diacetylmorphine (DAM)] are established treatments for HD in several countries. The present study examined whether DAM-maintained patients and methadone-maintained patients differ from healthy controls in startle reflex and cortisol levels. Fifty-seven participants, 19 of each group matched for age, sex and smoking status, completed a startle session which included the presentation of 24 bursts of white noise while eye-blink responses to startling noises were recorded. Salivary cortisol was collected three times after awakening, before, during and after the startle session. DAM was administered before the experiment, while methadone was administered afterwards. Both heroin-dependent patient groups exhibited significantly smaller startle responses than healthy controls (P < 0.05). Whereas the cortisol levels after awakening did not differ across the three groups, the experimental cortisol levels were significantly lower in DAM-maintained patients, who received their opioid before the experiment, than in methadone-maintained patients and healthy controls (P < 0.0001). Opioid maintenance treatment for HD is associated with reduced startle responses. Acute DAM administration may suppress cortisol levels, and DAM maintenance treatment may represent an effective alternative to methadone in stress-sensitive, heroin-dependent patients.

  17. A cost minimisation and Bayesian inference model predicts startle reflex modulation across species.

    PubMed

    Bach, Dominik R

    2015-04-07

    In many species, rapid defensive reflexes are paramount to escaping acute danger. These reflexes are modulated by the state of the environment. This is exemplified in fear-potentiated startle, a more vigorous startle response during conditioned anticipation of an unrelated threatening event. Extant explanations of this phenomenon build on descriptive models of underlying psychological states, or neural processes. Yet, they fail to predict invigorated startle during reward anticipation and instructed attention, and do not explain why startle reflex modulation evolved. Here, we fill this lacuna by developing a normative cost minimisation model based on Bayesian optimality principles. This model predicts the observed pattern of startle modification by rewards, punishments, instructed attention, and several other states. Moreover, the mathematical formalism furnishes predictions that can be tested experimentally. Comparing the model with existing data suggests a specific neural implementation of the underlying computations which yields close approximations to the optimal solution under most circumstances. This analysis puts startle modification into the framework of Bayesian decision theory and predictive coding, and illustrates the importance of an adaptive perspective to interpret defensive behaviour across species.

  18. Affective startle potentiation in juvenile offenders: the role of conduct problems and psychopathic traits.

    PubMed

    Syngelaki, Eva M; Fairchild, Graeme; Moore, Simon C; Savage, Justin C; van Goozen, Stephanie H M

    2013-01-01

    Emotion processing difficulties are observed in antisocial individuals exhibiting serious antisocial behavior. This study examined emotion processing in 40 male juvenile offenders (JOs) and 52 male controls by measuring startle reflex responses to aversive sounds during the passive viewing of affective and neutral images. JOs as a group exhibited reduced startle-elicited blinks across all slide categories compared to normal controls. Moreover, within the offender group those with more conduct disorder symptoms and higher levels of psychopathic traits displayed reduced startle amplitudes compared to lower-scoring offenders. The finding that startle magnitudes were inversely related to severity of conduct problems supports a dimensional or continuous approach to understanding externalizing disorders. Reductions in amygdala activity could lead to blunted startle magnitudes. The current findings not only provide further evidence that antisocial children have a general defensive motivational system dysfunction and present with impairments in neural systems that subserve emotion processing, but also show for the first time that those with more severe conduct problems have reduced startle responses compared to those who are less severely affected. The implications of these findings for interventions with JOs are discussed.

  19. Prepulse inhibition of the startle reflex and its attentional modulation in the human S-ketamine and N,N-dimethyltryptamine (DMT) models of psychosis.

    PubMed

    Heekeren, K; Neukirch, A; Daumann, J; Stoll, M; Obradovic, M; Kovar, K-A; Geyer, M A; Gouzoulis-Mayfrank, E

    2007-05-01

    Patients with schizophrenia exhibit diminished prepulse inhibition (PPI) of the acoustic startle reflex and deficits in the attentional modulation of PPI. Pharmacological challenges with hallucinogens are used as models for psychosis in both humans and animals. Remarkably, in contrast to the findings in schizophrenic patients and in animal hallucinogen models of psychosis, previous studies with healthy volunteers demonstrated increased levels of PPI after administration of low to moderate doses of either the antiglutamatergic hallucinogen ketamine or the serotonergic hallucinogen psilocybin. The aim of the present study was to investigate the influence of moderate and high doses of the serotonergic hallucinogen N,N-dimethyltryptamine (DMT) and the N-methyl-D-aspartate antagonist S-ketamine on PPI and its attentional modulation in humans. Fifteen healthy volunteers were included in a double-blind cross-over study with two doses of DMT and S-ketamine. Effects on PPI and its attentional modulation were investigated. Nine subjects completed both experimental days with the two doses of both drugs. S-ketamine increased PPI in both dosages, whereas DMT had no significant effects on PPI. S-ketamine decreased and DMT tended to decrease startle magnitude. There were no significant effects of either drug on the attentional modulation of PPI. In human experimental hallucinogen psychoses, and even with high, clearly psychotogenic doses of DMT or S-ketamine, healthy subjects failed to exhibit the predicted attenuation of PPI. In contrast, PPI was augmented and the startle magnitude was decreased after S-ketamine. These data point to important differences between human hallucinogen models and both animal hallucinogen models of psychosis and naturally occurring schizophrenia.

  20. Photoacoustic imaging of small organic molecule-based photoacoustic probe in subcutaneous tumor using P(VDF-TrFE) acoustic sensor

    NASA Astrophysics Data System (ADS)

    Hirasawa, Takeshi; Okawa, Shinpei; Kamiya, Mako; Urano, Yasuteru; Ishihara, Miya

    2015-03-01

    The P(VDF-TrFE) sensor which had uniform sensitivity in a frequency range of 2.9 - 19.6 MHz was developed for multispectral photoacoustic imaging (MS-PAI). A small organic molecule-based PA probe synthesized by our group had the absorption maximum at 530 nm and was used as a contrast agent. The PA probe was designed to have low quantum yield. Therefore, the PA probe efficiently converted absorbed optical energies to PA signals. The probe was injected in subcutaneous tumor of mice. Then, the subcutaneous tumor was imaged in vivo by using P(VDF-TrFE) sensor. MS-PAI successfully discriminated the probe signals from background signals produced from endogenous optical absorbers such as hemoglobin. The probe detectability of the P(VDF-TrFE) sensor was evaluated and then compared with that of lead zirconium titanate (PZT) sensors. The P(VDF-TrFE) sensor imaged the tumor more clearly than the PZT sensor with central frequency of 20 MHz, especially when the probe was accumulated in the tumor with low concentration. That was because the low-concentrated probe generated PA signals with low frequency. MS-PAI using P(VDF-TrFE) sensor which can detect PA signals with wide range of frequency is able to image various distribution of the probe and is superior to that using PZT sensor which detects PA signals with narrow frequency range.

  1. DEVELOPMENTAL THYROID HORMONE INSUFFICIENCY ALTERS THE AMPLITUDE OF THE ACOUSTIC STARTLE RESPONSE IN RATS

    EPA Science Inventory

    Purpose: The thyroid hormone (TH) system is one of the targets of endocrine disrupting chemicals. Since TH is essential for proper brain development, disruption by exposure to chemicals during development can result in adverse neurological outcomes. Previous studies revealed th...

  2. Stuttering in Adults: The Acoustic Startle Response, Temperamental Traits, and Biological Factors

    ERIC Educational Resources Information Center

    Alm, Per A.; Risberg, Jarl

    2007-01-01

    The purpose of this study was to investigate the relation between stuttering and a range of variables of possible relevance, with the main focus on neuromuscular reactivity, and anxiety. The explorative analysis also included temperament, biochemical variables, heredity, preonset lesions, and altered auditory feedback (AAF). An increased level of…

  3. Models and mechanisms of anxiety: evidence from startle studies

    PubMed Central

    Grillon, Christian

    2009-01-01

    Rationale Preclinical data indicates that threat stimuli elicit two classes of defensive behaviors, those that are associated with imminent danger and are characterized by avoidance or fight (fear), and those that are associated with temporally uncertain danger and are characterized by sustained apprehension and hypervigilance (anxiety). Objective To 1) review evidence for a distinction between fear and anxiety in animal and human experimental models using the startle reflex as an operational measure of aversive states, 2) describe experimental models of anxiety, as opposed to fear, in humans, 3) examine the relevance of these models to clinical anxiety. Results The distinction between phasic fear to imminent threat and sustained anxiety to temporally uncertain danger is suggested by psychopharmacological and behavioral evidence from ethological studies and can be traced back to distinct neuroanatomical systems, the amygdala and the bed nucleus of the stria terminalis. Experimental models of anxiety, not fear, are relevant to non-phobic anxiety disorders. Conclusions Progress in our understanding of normal and abnormal anxiety is critically dependent on our ability to model sustained aversive states to temporally uncertain threat. PMID:18058089

  4. Physiological reactivity of pregnant women to evoked fetal startle

    PubMed Central

    DiPietro, Janet A.; Voegtline, Kristin M.; Costigan, Kathleen A.; Aguirre, Frank; Kivlighan, Katie; Chen, Ping

    2013-01-01

    Objective The bidirectional nature of mother-child interaction is widely acknowledged during infancy and childhood. Prevailing models during pregnancy focus on unidirectional influences exerted by the pregnant woman on the developing fetus. Prior work has indicated that the fetus also affects the pregnant woman. Our objective was to determine whether a maternal psychophysiological response to stimulation of the fetus could be isolated. Methods Using a longitudinal design, an airborne auditory stimulus was used to elicit a fetal heart rate and motor response at 24 (n = 47) and 36 weeks (n = 45) gestation. Women were blind to condition (stimulus versus sham). Maternal parameters included cardiac (heart rate) and electrodermal (skin conductance) responses. Multilevel modeling of repeated measures with 5 data points per second was used to examine fetal and maternal responses. Results As expected, compared to a sham condition, the stimulus generated a fetal motor response at both gestational ages, consistent with a mild fetal startle. Fetal stimulation was associated with significant, transient slowing of maternal heart rate coupled with increased skin conductance within 10 s of the stimulus at both gestational ages. Nulliparous women showed greater electrodermal responsiveness. The magnitude of the fetal motor response significantly corresponded to the maternal skin conductance response at 5, 10, 15, and 30 s following stimulation. Conclusion Elicited fetal movement exerts an independent influence on the maternal autonomic nervous system. This finding contributes to current models of the dyadic relationship during pregnancy between fetus and pregnant woman. PMID:24119937

  5. Acoustic Neuroma

    MedlinePlus

    ... search IRSA's site Unique Hits since January 2003 Acoustic Neuroma Click Here for Acoustic Neuroma Practice Guideline ... to microsurgery. One doctor's story of having an acoustic neuroma In August 1991, Dr. Thomas F. Morgan ...

  6. Oxytocin and Social Support as Synergistic Inhibitors of Aversive Fear Conditioning and Fear-Potentiated Startle in Male Rats

    DTIC Science & Technology

    2011-05-01

    Oxytocin and Social Support as Synergistic Inhibitors of Aversive Fear Conditioning and Fear-Potentiated Startle in Male Rats Dr. Jeff Rosen University of...potentiated startle after 3 weeks of social isolation have been difficult to replicate. We suggest oxytocin is promising as a drug with novel...benefits for patients with PTSD. fear; anxiety; PTSD; startle; social isolation 60 jrosen@udel.edu Table of Contents

  7. Oxytocin and Social Support as Synergistic Inhibitors of Aversive Fear Conditioning and Fear-Potentiated Startle in Male Rats

    DTIC Science & Technology

    2009-09-01

    startle amplitude. They then received Pavlovian fear conditioning of five pairings of a 3 s light co-terminating with a 500 ms, 0.6mA footshock. Four...Synergistic Inhibitors of Aversive Fear Conditioning and Fear-Potentiated Startle in Male Rats PRINCIPAL INVESTIGATOR: Jeffrey B. Rosen, Ph.D...NUMBER Oxytocin and Social Support as Synergistic Inhibitors of Aversive Fear Conditioning and Fear-Potentiated Startle in Male Rats 5b. GRANT

  8. Passive broadband acoustic thermometry

    NASA Astrophysics Data System (ADS)

    Anosov, A. A.; Belyaev, R. V.; Klin'shov, V. V.; Mansfel'd, A. D.; Subochev, P. V.

    2016-04-01

    The 1D internal (core) temperature profiles for the model object (plasticine) and the human hand are reconstructed using the passive acoustothermometric broadband probing data. Thermal acoustic radiation is detected by a broadband (0.8-3.5 MHz) acoustic radiometer. The temperature distribution is reconstructed using a priori information corresponding to the experimental conditions. The temperature distribution for the heated model object is assumed to be monotonic. For the hand, we assume that the temperature distribution satisfies the heat-conduction equation taking into account the blood flow. The average error of reconstruction determined for plasticine from the results of independent temperature measurements is 0.6 K for a measuring time of 25 s. The reconstructed value of the core temperature of the hand (36°C) generally corresponds to physiological data. The obtained results make it possible to use passive broadband acoustic probing for measuring the core temperatures in medical procedures associated with heating of human organism tissues.

  9. Hypnotizability, Hypnosis and Prepulse Inhibition of the Startle Reflex in Healthy Women: An ERP Analysis

    PubMed Central

    De Pascalis, Vilfredo; Russo, Emanuela

    2013-01-01

    A working model of the neurophysiology of hypnosis suggests that highly hypnotizable individuals (HHs) have more effective frontal attentional systems implementing control, monitoring performance, and inhibiting unwanted stimuli from conscious awareness, than low hypnotizable individuals (LHs). Recent studies, using prepulse inhibition (PPI) of the auditory startle reflex (ASR), suggest that HHs, in the waking condition, may show reduced sensory gating although they may selectively attend and disattend different stimuli. Using a within subject design and a strict subject selection procedure, in waking and hypnosis conditions we tested whether HHs compared to LHs showed a significantly lower inhibition of the ASR and startle-related brain activity in both time and intracerebral source localization domains. HHs, as compared to LH participants, exhibited (a) longer latency of the eyeblink startle reflex, (b) reduced N100 responses to startle stimuli, and (c) higher PPI of eyeblink startle and of the P200 and P300 waves. Hypnosis yielded smaller N100 waves to startle stimuli and greater PPI of this component than in the waking condition. sLORETA analysis revealed that, for the N100 (107 msec) elicited during startle trials, HHs had a smaller activation in the left parietal lobe (BA2/40) than LHs. Auditory pulses of pulse-with prepulse trials in HHs yielded less activity of the P300 (280 msec) wave than LHs, in the cingulate and posterior cingulate gyrus (BA23/31). The present results, on the whole, are in the opposite direction to PPI findings on hypnotizability previously reported in the literature. These results provide support to the neuropsychophysiological model that HHs have more effective sensory integration and gating (or filtering) of irrelevant stimuli than LHs. PMID:24278150

  10. Intolerance of uncertainty and startle potentiation in relation to different threat reinforcement rates.

    PubMed

    Chin, Brian; Nelson, Brady D; Jackson, Felicia; Hajcak, Greg

    2016-01-01

    Fear conditioning research on threat predictability has primarily examined the impact of temporal (i.e., timing) predictability on the startle reflex. However, there are other key features of threat that can vary in predictability. For example, the reinforcement rate (i.e., frequency) of threat is a crucial factor underlying fear learning. The present study examined the impact of threat reinforcement rate on the startle reflex and self-reported anxiety during a fear conditioning paradigm. Forty-five participants completed a fear learning task in which the conditioned stimulus was reinforced with an electric shock to the forearm on 50% of trials in one block and 75% of trials in a second block, in counter-balanced order. The present study also examined whether intolerance of uncertainty (IU), the tendency to perceive or experience uncertainty as stressful or unpleasant, was associated with the startle reflex during conditions of low (50%) vs. high (75%) reinforcement. Results indicated that, across all participants, startle was greater during the 75% relative to the 50% reinforcement condition. IU was positively correlated with startle potentiation (i.e., increased startle response to the CS+ relative to the CS-) during the 50%, but not the 75%, reinforcement condition. Thus, despite receiving fewer electric shocks during the 50% reinforcement condition, individuals with high IU uniquely demonstrated greater defense system activation when impending threat was more uncertain. The association between IU and startle was independent of state anxiety. The present study adds to a growing literature on threat predictability and aversive responding, and suggests IU is associated with abnormal responding in the context of uncertain threat.

  11. Immobility and hyperthermia in the tail suspension test: association with the Porsolt test and the reflex startle reaction in 11 inbred mouse strains and the effects of genetic knockout of MAO A.

    PubMed

    Popova, N K; Tibeikina, M A

    2010-06-01

    Immobility and hyperthermia induced by unavoidable stress imposed by the tail suspension test (TST) and the acoustic startle reaction were assessed in mice of 11 inbred strains and in Tg8 mice, which have genetic knockout of MAO A. Sharp genotypic differences in immobility were seen, while there was no correlation with the hyperthermic response to the TST. A correlation was found between the extent of immobility in the TST and the startle reaction. Studies of 11 strains of mice revealed a positive correlation between the duration of immobility in the TST and the Porsolt "despair test." Genetic knockout of MAO A, one of the key enzymes in catecholamine and serotonin metabolism in the brain, weakened the startle reaction and TST-induced hyperthermia but had no significant effect on the immobility of Tg8 mice, which provides evidence of differences in the neurochemical regulation of these reactions. These data provide grounds for using the TST as a "dry" Porsolt test and identify TST-induced hyperthermia as a model for reactions to unavoidable stress.

  12. Distinct Contributions of Median Raphe Nucleus to Contextual Fear Conditioning and Fear-Potentiated Startle

    PubMed Central

    Silva, R. C. B.; Cruz, A. P. M.; Avanzi, V.; Landeira-Fernandez, J.; Brandão, M. L.

    2002-01-01

    Ascending 5-HT projections from the median raphe nucleus (MRN), probably to the hippocampus, are implicated in the acquisition of contextual fear (background stimuli), as assessed by freezing behavior. Foreground cues like light, used as a conditioned stimulus (CS) in classical fear conditioning, also cause freezing through thalamic transmission to the amygdala. As the MRN projects to the hippocampus and amygdala, the role of this raphe nucleus in fear conditioning to explicit cues remains to be explained. Here we analyzed the behavior of rats with MRN electrolytic lesions in a contextual conditioning situation and in a fear-potentiated startle procedure. The animals received MRN electrolytic lesions either before or on the day after two consecutive training sessions in which they were submitted to 10 conditioning trials, each in an experimental chamber (same context) where they. received foot-shocks (0.6 mA, 1 sec) paired to a 4-sec light CS. Seven to ten days later, the animals were submitted to testing sessions for assessing conditioned fear when they were placed for five shocks, and the duration of contextual freezing was recorded. The animals were then submitted to a fear-potentiated startle in response to a 4-sec light-CS, followed by white noise (100 dB, 50 ms). Control rats (sham) tested in the same context showed more freezing than did rats with pre- or post-training MRN lesions. Startle was clearly potentiated in the presence of light CS in the sham-lesioned animals. Whereas pretraining lesions reduced both freezing and fear-potentiated startle, the post-training lesions reduced only freezing to context, without changing the fear-potentiated startle. In a second experiment, neurotoxic lesions of the MRN with local injections of N-methyl-D-aspartate or the activation of 5-HT1A somatodendritic auto-receptors of the MRN by microinjections of the 5-HT1A receptor agonist 8-hydroxy- 2-(di-n-propylamino)tetralin (8-OH-DPAT) before the training sessions also

  13. Evidence for Startle Effects due to Externally Induced Lower Limb Movements: Implications in Neurorehabilitation

    PubMed Central

    Mayr, Andreas; Saltuari, Leopold

    2017-01-01

    Passive limb displacement is routinely used to assess muscle tone. If we attempt to quantify muscle stiffness using mechanical devices, it is important to know whether kinematic stimuli are able to trigger startle reactions. Whether kinematic stimuli are able to elicit a startle reflex and to accelerate prepared voluntary movements (StartReact effect) has not been studied extensively to date. Eleven healthy subjects were suspended in an exoskeleton and were exposed to passive left knee flexion (KF) at three intensities, occasionally replaced by fast right KF. Upon perceiving the movement subjects were asked to perform right wrist extension (WE), assessed by extensor carpi radialis (ECR) electromyographic activity. ECR latencies were shortest in fast trials. Startle responses were present in most fast trials, yet being significantly accelerated and larger with right versus left KF, since the former occurred less frequently and thus less expectedly. Startle responses were associated with earlier and larger ECR responses (StartReact effect), with the largest effect again upon right KF. The results provide evidence that kinematic stimuli are able to elicit both startle reflexes and a StartReact effect, which depend on stimulus intensity and anticipation, as well as on the subjects' preparedness to respond. PMID:28299334

  14. Startle reflex hyporeactivity in Parkinson's disease: an emotion-specific or arousal-modulated deficit?

    PubMed Central

    Miller, K.M.; Okun, M.S.; Marsiske, M.; Fennell, E.B.; Bowers, D.

    2009-01-01

    We previously reported that patients with Parkinson's disease (PD) demonstrate reduced psychophysiologic reactivity to unpleasant pictures as indexed by diminished startle eyeblink magnitude (Bowers et al., 2006). In the present study, we tested the hypothesis that this hyporeactivity was primarily driven by diminished reactivity to fear-eliciting stimuli as opposed to other types of aversive pictures. This hypothesis was based on previous evidence suggesting amygdalar abnormalities in PD patients coupled with the known role of the amygdala in fear processing. To test this hypothesis, 24 patients with Parkinson's disease and 24 controls viewed standardized sets of emotional pictures that depicted fear, disgust (mutilations, contaminations), pleasant, and neutral contents. Startle eyeblinks were elicited while subjects viewed these emotional pictures. Results did not support the hypothesis of a specific deficit to fear pictures. Instead, the PD patients had reduced reactivity to mutilation pictures relative to other types of negative pictures in the context of normal subjective ratings. Further analyses revealed that controls displayed a pattern of increased startle eyeblink magnitude for “high arousal” versus “low arousal” negative pictures, regardless of picture category, whereas startle eyeblink magnitude in the PD group did not vary by arousal level. These results suggest that previous findings of decreased aversion-modulated startle is driven by reduced reactivity to highly arousing negative stimuli rather than to a specific category (i.e., fear or disgust) of emotion stimuli. PMID:19428424

  15. Thermal Imaging of the Periorbital Regions during the Presentation of an Auditory Startle Stimulus

    PubMed Central

    Gane, Luke; Power, Sarah; Kushki, Azadeh; Chau, Tom

    2011-01-01

    Infrared thermal imaging of the inner canthi of the periorbital regions of the face can potentially serve as an input signal modality for an alternative access system for individuals with conditions that preclude speech or voluntary movement, such as total locked-in syndrome. However, it is unknown if the temperature of these regions is affected by the human startle response, as changes in the facial temperature of the periorbital regions manifested during the startle response could generate false positives in a thermography-based access system. This study presents an examination of the temperature characteristics of the periorbital regions of 11 able-bodied adult participants before and after a 102 dB auditory startle stimulus. The results indicate that the startle response has no substantial effect on the mean temperature of the periorbital regions. This indicates that thermography-based access solutions would be insensitive to startle reactions in their user, an important advantage over other modalities being considered in the context of access solutions for individuals with a severe motor disability. PMID:22073302

  16. The effects of an auditory startle on obstacle avoidance during walking

    PubMed Central

    Queralt, Ana; Weerdesteyn, Vivian; van Duijnhoven, Hanneke J R; Castellote, Juan M; Valls-Solé, Josep; Duysens, Jacques

    2008-01-01

    Movement execution is speeded up when a startle auditory stimulus is applied with an imperative signal in a simple reaction time task experiment, a phenomenon described as StartReact. The effect has been recently observed in a step adjustment task requiring fast selection of specific movements in a choice reaction time task. Therefore, we hypothesized that inducing a StartReact effect may be beneficial in obstacle avoidance under time pressure, when subjects have to perform fast gait adjustments. Twelve healthy young adults walked on a treadmill and obstacles were released in specific moments of the step cycle. On average the EMG onset latency in the biceps femoris shortened by 20% while amplitude increased by 50%, in trials in which an auditory startle accompanied obstacle avoidance. The presentation of a startle increased the probability of using a long step strategy, enlarged stride length modifications and resulted in higher success rates, to avoid the obstacle. We also examined the effects of the startle in a condition in which the obstacle was not present in comparison to a condition in which the obstacle was visibly present but it did not fall. In the latter condition, the obstacle avoidance reaction occurred with a similar latency but smaller amplitude as in trials in which the obstacle was actually released. Our results suggest that the motor programmes used for obstacle avoidance are probably stored at subcortical structures. The release of these motor programmes by a startling auditory stimulus may combine intersensory facilitation and the StartReact effect. PMID:18653659

  17. Developmental lead exposure causes startle response deficits in zebrafish.

    PubMed

    Rice, Clinton; Ghorai, Jugal K; Zalewski, Kathryn; Weber, Daniel N

    2011-10-01

    Lead (Pb(2+)) exposure continues to be an important concern for fish populations. Research is required to assess the long-term behavioral effects of low-level concentrations of Pb(2+) and the physiological mechanisms that control those behaviors. Newly fertilized zebrafish embryos (<2h post fertilization; hpf) were exposed to one of three concentrations of lead (as PbCl(2)): 0, 10, or 30 nM until 24 hpf. (1) Response to a mechanosensory stimulus: Individual larvae (168 hpf) were tested for response to a directional, mechanical stimulus. The tap frequency was adjusted to either 1 or 4 taps/s. Startle response was recorded at 1000 fps. Larvae responded in a concentration-dependent pattern for latency to reaction, maximum turn velocity, time to reach V(max) and escape time. With increasing exposure concentrations, a larger number of larvae failed to respond to even the initial tap and, for those that did respond, ceased responding earlier than control larvae. These differences were more pronounced at a frequency of 4 taps/s. (2) Response to a visual stimulus: Fish, exposed as embryos (2-24 hpf) to Pb(2+) (0-10 μM) were tested as adults under low light conditions (≈ 60 μW/m(2)) for visual responses to a rotating black bar. Visual responses were significantly degraded at Pb(2+) concentrations of 30 nM. These data suggest that zebrafish are viable models for short- and long-term sensorimotor deficits induced by acute, low-level developmental Pb(2+) exposures.

  18. Fear conditioning of SCR but not the startle reflex requires conscious discrimination of threat and safety.

    PubMed

    Sevenster, Dieuwke; Beckers, Tom; Kindt, Merel

    2014-01-01

    There is conflicting evidence as to whether awareness is required for conditioning of the skin conductance response (SCR). Recently, Schultz and Helmstetter (2010) reported SCR conditioning in contingency unaware participants by using difficult to discriminate stimuli. These findings are in stark contrast with other observations in human fear conditioning research, showing that SCR predominantly reflects contingency learning. Therefore, we repeated the study by Schultz and Helmstetter and additionally measured conditioning of the startle response, which seems to be less sensitive to declarative knowledge than SCR. While we solely observed SCR conditioning in participants who reported awareness of the contingencies (n = 16) and not in the unaware participants (n = 18), we observed startle conditioning irrespective of awareness. We conclude that SCR but not startle conditioning depends on conscious discriminative fear learning.

  19. In Your Face: Startle to Emotional Facial Expressions Depends on Face Direction

    PubMed Central

    Michalsen, Henriette; Øvervoll, Morten

    2017-01-01

    Although faces are often included in the broad category of emotional visual stimuli, the affective impact of different facial expressions is not well documented. The present experiment investigated startle electromyographic responses to pictures of neutral, happy, angry, and fearful facial expressions, with a frontal face direction (directed) and at a 45° angle to the left (averted). Results showed that emotional facial expressions interact with face direction to produce startle potentiation: Greater responses were found for angry expressions, compared with fear and neutrality, with directed faces. When faces were averted, fear and neutrality produced larger responses compared with anger and happiness. These results are in line with the notion that startle is potentiated to stimuli signaling threat. That is, a forward directed angry face may signal a threat toward the observer, and a fearful face directed to the side may signal a possible threat in the environment. PMID:28321290

  20. The time course of face processing: startle eyeblink response modulation by face gender and expression.

    PubMed

    Duval, Elizabeth R; Lovelace, Christopher T; Aarant, Justin; Filion, Diane L

    2013-12-01

    The purpose of this study was to investigate the effects of both facial expression and face gender on startle eyeblink response patterns at varying lead intervals (300, 800, and 3500ms) indicative of attentional and emotional processes. We aimed to determine whether responses to affective faces map onto the Defense Cascade Model (Lang et al., 1997) to better understand the stages of processing during affective face viewing. At 300ms, there was an interaction between face expression and face gender with female happy and neutral faces and male angry faces producing inhibited startle. At 3500ms, there was a trend for facilitated startle during angry compared to neutral faces. These findings suggest that affective expressions are perceived differently in male and female faces, especially at short lead intervals. Future studies investigating face processing should take both face gender and expression into account.

  1. In Your Face: Startle to Emotional Facial Expressions Depends on Face Direction.

    PubMed

    Åsli, Ole; Michalsen, Henriette; Øvervoll, Morten

    2017-01-01

    Although faces are often included in the broad category of emotional visual stimuli, the affective impact of different facial expressions is not well documented. The present experiment investigated startle electromyographic responses to pictures of neutral, happy, angry, and fearful facial expressions, with a frontal face direction (directed) and at a 45° angle to the left (averted). Results showed that emotional facial expressions interact with face direction to produce startle potentiation: Greater responses were found for angry expressions, compared with fear and neutrality, with directed faces. When faces were averted, fear and neutrality produced larger responses compared with anger and happiness. These results are in line with the notion that startle is potentiated to stimuli signaling threat. That is, a forward directed angry face may signal a threat toward the observer, and a fearful face directed to the side may signal a possible threat in the environment.

  2. Startle-induced seizures associated with infantile hemiplegia: implication of the supplementary motor area.

    PubMed

    Nolan, Melinda A; Otsubo, Hiroshi; Iida, Koji; Minassian, Berge A

    2005-03-01

    This case illustrates an uncommon form of symptomatic startle-induced epilepsy associated with infantile hemiplegia. Seizure semiology, neuroimaging and neurophysiological findings support involvement of the supplementary motor area in the generation of this seizure type. We present the case of an 11-year-old girl with an uncommon form of startle-induced seizures, illustrated on video-EEG, against the background of left infantile hemiplegia associated with extensive right hemispheric porencephaly but preserved cognitive functioning. The epileptic focus appears to be in the dorsolateral frontal lobe, with seizure semiology involving the supplementary motor cortex.

  3. From appetitive to aversive: motivational interviewing reverses the modulation of the startle reflex by tobacco cues in smokers not ready to quit.

    PubMed

    Gantiva, Carlos; Guerra, Pedro; Vila, Jaime

    2015-03-01

    Motivational Interviewing (MI) is a treatment method that has proven effective for increasing motivation to change and decreasing the consumption of different drugs. However, the results of studies examining the impact of MI on tobacco consumption are contradictory. Moreover, evidence of the effectiveness of MI for modifying well-validated psychophysiological indices of motivational change is still lacking. The aim of the present study was to use the startle probe paradigm and self-report measures of motivational change to assess the effectiveness of MI, compared to Prescriptive Advice (PA) and no treatment, in a sample of 53 smokers (28 male) who were not ready to quit smoking. After the intervention, the MI group reported increased motivation to change compared to both the PA and control groups. MI participants also had a potentiated startle reflex in response to tobacco-related pictures compared to the other two groups. These findings provide evidence that MI reverses the underlying motivational system activated by tobacco related cues.

  4. Acoustic Neuroma

    MedlinePlus

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. ... can press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the ...

  5. Assessing the Comprehensive Soldier Fitness Program: Measuring Startle Response and Prepulse Inhibition

    DTIC Science & Technology

    2011-04-01

    prescribed anxiolytic (anxiety-reducing) drugs, which can artificially increase PPI and decrease startle response (Braff et al., 2001). Nicotine can...increase PPI, but dopamine agonists can have the opposite effect by reducing PPI. Fortunately, caffeine appears to have no significant effect on PPI

  6. Alcohol delays the emergence of the fetal elicited startle response, but only transiently.

    PubMed

    Hepper, Peter G; Dornan, James C; Lynch, Catherine; Maguire, Jennifer F

    2012-08-20

    Prenatal exposure to alcohol may exert a significant detrimental effect on the functioning of the individual's brain, however few studies have examined this before birth. This longitudinal study examined the effect of maternal alcohol consumption on the elicited startle response of the fetus. Two groups of fetuses were examined: one whose mothers drank alcohol (approximately 10 units per week); the other whose mothers did not drink alcohol. Fetuses were examined at 29, 32 and 35 weeks gestation and their startle response observed using ultrasound in response to 2 presentations of a pink noise (70-250Hz) at 90dB(A) separated by 30s. Fetuses exposed to alcohol exhibited a weaker startle response at 29 weeks gestation than did fetuses not exposed to alcohol. There was no difference in the response at 32 and 35 weeks gestation. To ensure that the effects were not due to a more general effect of alcohol on fetal movement, a second experiment compared the spontaneous movements (observed on ultrasound for 45 min) of fetuses whose mothers drank alcohol and fetuses of mothers who didn't drink alcohol. There were no differences in movements exhibited by the fetuses. The results suggest that exposure to alcohol delays the emergence of the elicited startle response at 29 weeks gestation but this delay has disappeared by 32 weeks gestation. The possible role of altered neural development, acute exposure to alcohol and disruptions to the fetus's behavioural repertoire, in mediating these effects are discussed.

  7. Evidence of Fearlessness in Behaviourally Disordered Children: A Study on Startle Reflex Modulation

    ERIC Educational Resources Information Center

    van Goozen, Stephanie H. M.; Snoek, Heddeke; Matthys, Walter; van Rossum, Inge; van Engeland, Herman

    2004-01-01

    Background: Patterns of low heart rate, skin conductance and cortisol seem to characterise children with disruptive behaviour disorder (DBD). Until now, the startle paradigm has not been used in DBD children. We investigated whether DBD children, like adult psychopaths, process emotional stimuli in an abnormal way. Method: Twenty-one DBD and 33…

  8. Evaluation of the Hair Cell Regeneration in Zebrafish Larvae by Measuring and Quantifying the Startle Responses

    PubMed Central

    Wang, Changquan; Zhong, Zhenmin; Sun, Peng

    2017-01-01

    The zebrafish has become an established model organism for the study of hearing and balance systems in the past two decades. The classical approach to examine hair cells is to use dye to conduct selective staining, which shows the number and morphology of hair cells but does not reveal their function. Startle response is a behavior closely related to the auditory function of hair cells; therefore it can be used to measure the function of hair cells. In this study, we developed a device to measure the startle response of zebrafish larvae. By applying various levels of stimulus, it showed that the system can discern a 10 dB difference. The hair cell in zebrafish can regenerate after damage due to noise exposure or drug treatment. With this device, we measured the startle response of zebrafish larvae during and after drug treatment. The results show a similar trend to the classical hair cell staining method. The startle response was reduced with drug treatment and recovered after removal of the drug. Together it demonstrated the capability of this behavioral assay in evaluating the hair cell functions of fish larvae and its potential as a high-throughput screening tool for auditory-related gene and drug discovery. PMID:28250994

  9. Neural Systems Involved in Fear and Anxiety Measured with Fear-Potentiated Startle

    ERIC Educational Resources Information Center

    Davis, Michael

    2006-01-01

    A good deal is now known about the neural circuitry involved in how conditioned fear can augment a simple reflex (fear-potentiated startle). This involves visual or auditory as well as shock pathways that project via the thalamus and perirhinal or insular cortex to the basolateral amygdala (BLA). The BLA projects to the central (CeA) and medial…

  10. Conditioned Fear Extinction and Reinstatement in a Human Fear-Potentiated Startle Paradigm

    ERIC Educational Resources Information Center

    Norrholm, Seth D.; Jovanovic, Tanja; Vervliet, Bram; Myers, Karyn M.; Davis, Michael; Rothbaum, Barbara O.; Duncan, Erica J.

    2006-01-01

    The purpose of this study was to analyze fear extinction and reinstatement in humans using fear-potentiated startle. Participants were fear conditioned using a simple discrimination procedure with colored lights as the conditioned stimuli (CSs) and an airblast to the throat as the unconditioned stimulus (US). Participants were extinguished 24 h…

  11. Startle modulation in non-incarcerated men and women with psychopathic traits.

    PubMed

    Justus, Alicia N; Finn, Peter R

    2007-12-01

    Past research has demonstrated that individuals with psychopathic characteristics are under-responsive to aversive stimuli, however, much of this work has failed to include non-incarcerated samples, or to examine gender differences in this relationship. Additionally, few studies have examined the role of specific personality characteristics, as they relate to both psychopathic behavior and emotional responsiveness. The current study assessed emotional modulation of the startle response in a community sample of 108 men and women (99 with usable startle data) during perception of emotion-laden photographs. Consistent with previous work, men reporting high levels of psychopathy failed to show the typical increase in the startle response when exposed to aversive photographs, but only when responses were elicited relatively early in picture viewing (i.e., 2.0 s as compared to 4.5 s post-photograph onset). Additionally, both genders showed a significant effect of harm avoidance and anxiety on modulation of the startle response, such that individuals reporting low levels of each trait failed to show significant responses to aversive photographs. These results suggest that while deficits in emotional processing extend to non-incarcerated samples, the relationship may be influenced by additional factors including gender, personality, and attributes related to incarceration.

  12. Acoustic Seaglider

    DTIC Science & Technology

    2008-03-07

    a national naval responsibility. Acoustic sensors on mobile, autonomous platforms will enable basic research topics on temporal and spatial...problem and acoustic navigation and communications within the context of distributed autonomous persistent undersea surveillance sensor networks...Acoustic sensors on mobile, autonomous platforms will enable basic research topics on temporal and spatial coherence and the description of ambient

  13. Acoustic seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  14. Acoustic Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  15. Asians demonstrate reduced sensitivity to unpredictable threat: a preliminary startle investigation using genetic ancestry in a multiethnic sample.

    PubMed

    Nelson, Brady D; Bishop, Jeffrey R; Sarapas, Casey; Kittles, Rick A; Shankman, Stewart A

    2014-06-01

    Research has indicated that individuals of Asian descent, relative to other racial groups, demonstrate reduced emotional responding and lower prevalence rates of several anxiety disorders. It is unclear though whether these group differences extend to biomarkers of anxiety disorders and whether genetic differences play a role. This study compared self-identified Caucasian, Latino, and Asian persons (total N = 174) on startle response during a baseline period and while anticipating unpredictable threat-a putative biomarker for certain anxiety disorders--as well as predictable threat. In addition, the association between genetic ancestry and startle response was examined within each racial group to determine potential genetic influences on responding. For the baseline period, Asian participants exhibited a smaller startle response relative to Caucasian and Latino participants, who did not differ. Within each racial group, genetic ancestry was associated with baseline startle. Furthermore, genetic ancestry mediated racial group differences in baseline startle. For the threat conditions, a Race × Condition interaction indicated that Asian participants exhibited reduced startle potentiation to unpredictable, but not predicable, threat relative to Caucasian and Latino participants, who did not differ. However, genetic ancestry was not associated with threat-potentiated startle in any racial group. This study adds to the growing literature on racial differences in emotional responding and provides preliminary evidence suggesting that genetic ancestry may play an important role. Moreover, reduced sensitivity to unpredictable threat may reflect a mechanism for why individuals of Asian descent are at less risk for particular anxiety disorders relative to other racial groups.

  16. Facilitation and habituation of the startle reflex over the tonically active biceps brachii muscle contralateral to electrical stimuli.

    PubMed

    Alaid, Ssuhir; Tyagi, Indu; Kornhuber, Malte

    2012-10-03

    The aim of the present investigation was to explore the impact of muscle contraction on startle reflex responses after electrical stimuli (single or trains of 3) and to study startle reflex habituation. The electromyogram was recorded over the tonically active biceps brachii muscle in 19 healthy subjects contralateral to electrical stimuli (9-12mA) that were delivered at 1.0 and 0.4Hz over the superficial radial nerve. The muscle contraction level was varied by loading weight on the subject's bent arm (0.0, 1.0 or 1.5kg). Furthermore, short term reflex habituation was investigated using 30 blocks of 5 subsequent stimuli. Startle response amplitudes gained significantly (p<0.05) after (i) train stimuli as compared with single stimuli, during (ii) high versus low levels of muscle contraction, and at (iii) 0.4Hz versus 1.0Hz stimuli. Startle reflex amplitudes decreased significantly by the influence of preceding stimuli (p<0.05). This study provides evidence that the startle reflex can be significantly influenced by weight load, i.e. by volitional influences. Startle reflex investigation over a contracted limb muscle results in a high probability of startle release and thereby improved detection of SR habituation following preceding stimuli.

  17. Fast and singular muscle responses initiate the startle response of Pantodon buchholzi (Osteoglossomorpha).

    PubMed

    Starosciak, A K; Kalola, R P; Perkins, K P; Riley, J A; Saidel, W M

    2008-01-01

    The startle response of Pantodon buchholzi, the African butterfly fish, is a complete or incomplete ballistic jump resulting from abduction of the pectoral fins. This study analyzed the neuromuscular basis for such a jump by recording in vivo electromyograms (emgs) from the muscles of abduction, the muscularis abductor superficialis (MAS) and the muscularis abductor profundus (MAP). The motor neurons innervating the MAS muscle were localized by retrograde transport of biocytin. The latency between stimulus and the evoked emg in the MAS was less than 5 ms; the latency of the MAP was about 6.5 ms. A single emg was recorded per jump. High speed video demonstrated that onset of a startle movement began within 10 ms of the onset of fin abduction. The emg associated with this movement is short (<2 ms) and followed by a variably-shaped, slower and smaller potential of 10-30 ms duration. The brief period between stimulus and startle response of Pantodon suggests a Mauthner neuron-related response, only with the behavior occurring in the vertical plane. The MAS may act only in a startle response, whereas the MAP might have a role in other behaviors. Elicited jumping habituates after a single trial. Electrophysiological evidence is presented indicating that the innervating motor neurons are suppressed for seconds following a stimulus. The neurons innervating the MAS are located at the medullary-spinal cord junction and possess an average radius of approximately 17.9 mum. These fish have been historically described as 'fresh water' flying fish. As a single emg occurs per startle response, repetitive pectoral activity generating flying cannot be supported. Pantodon 'flight' is ballistic.

  18. Acoustic/Magnetic Stress Sensor

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.; Namkung, M.

    1986-01-01

    High-resolution sensor fast, portable, does not require permanent bonding to structure. Sensor measures nondestructively type (compressive or tensile) and magnitude of stresses and stress gradients present in class of materials. Includes precise high-resolution acoustic interferometer, sending acoustic transducer, receiving acoustic transducer, electromagnet coil and core, power supply, and magnetic-field-measuring device such as Hall probe. This measurement especially important for construction and applications where steel is widely used. Sensor useful especially for nondestructive evaluation of stress in steel members because of portability, rapid testing, and nonpermanent installation.

  19. Acoustic Doppler velocimeter-induced acoustic streaming and its implications for measurement

    NASA Astrophysics Data System (ADS)

    Poindexter, C. M.; Rusello, P. J.; Variano, E. A.

    2011-05-01

    The acoustic Doppler velocimeter (ADV) is widely used for the characterization of fluid flow. Secondary flows ("acoustic streaming") generated by the ADV's acoustic pulses may affect the accuracy of measurements in experiments with small velocities. We assessed the impact of acoustic streaming on flow measurement using particle image velocimetry. The probes of two different ADVs were successively mounted in a tank of quiescent water. The probes' ultrasound emitters were aligned with a laser light sheet. Observed flow was primarily in the axial direction, accelerating from the ultrasound emitter and peaking within centimeters of the velocimeter sampling volume before dropping off. We measured the dependence of acoustic streaming velocity on ADV configuration, finding that different settings induce streaming ranging from negligible to more than 2.0 cm s-1. From these results, we describe cases where acoustic streaming affects velocity measurements and also cases where ADVs accurately measure their own acoustic streaming.

  20. Effects of the psychotomimetic benzomorphan N-allylnormetazocine (SKF 10,047) on prepulse inhibition of startle in mice.

    PubMed

    Halberstadt, Adam L; Hyun, James; Ruderman, Michael A; Powell, Susan B

    2016-09-01

    N-allylnormetazocine (NANM; SKF 10,047) is a benzomorphan opioid that produces psychotomimetic effects. (+)-NANM is the prototypical agonist for the sigma-1 (σ1) receptor, and there is a widespread belief that the hallucinogenic effects of NANM and other benzomorphan derivatives are mediated by interactions with σ1 sites. However, NANM is also an agonist at the κ opioid receptor (KOR) and binds to the PCP site located within the channel pore of the NMDA receptor, interactions that could potentially contribute to the effects of NANM. NMDA receptor antagonists such as phencyclidine (PCP) and ketamine are known to disrupt prepulse inhibition (PPI) of acoustic startle, a measure of sensorimotor gating, in rodents. We recently found that racemic NANM disrupts PPI in rats, but it is not clear whether the effect is mediated by blockade of the NMDA receptor, or alternatively whether interactions with KOR and σ1 receptors are involved. The present studies examined whether NANM and its stereoisomers alter PPI in C57BL/6J mice, and tested whether the effects on PPI are mediated by KOR or σ1 receptors. Racemic NANM produced a dose-dependent disruption of PPI (3-30mg/kg SC). (+)-NANM also disrupted PPI, whereas (-)-NANM was ineffective. Pretreatment with the selective KOR antagonist nor-binaltorphimine (10mg/kg SC) or the selective σ1 antagonist NE-100 (1mg/kg IP) failed to attenuate the reduction in PPI produced by racemic NANM. We also found that the selective KOR agonist (-)-U-50,488H (10-40mg/kg SC) had no effect on PPI. These findings confirm that NANM reduces sensorimotor gating in rodents, and indicate that the effect is mediated by interactions with the PCP receptor and not by activation of KOR or σ1 receptors. This observation is consistent with evidence indicating that the σ1 receptor is not linked to hallucinogenic or psychotomimetic effects.

  1. Surface acoustic waves as a probe of the Wigner crystal in n-GaAs/AlGaAs in vicinity of ∘ ν = 1 / 5 , 1, and 2

    NASA Astrophysics Data System (ADS)

    Suslov, A. V.; Drichko, I. L.; Smirnov, I. Yu.; Pfeiffer, L. N.; West, K. W.; Galperin, Y. M.

    Both attenuation of a surface acoustic wave (SAW) and variation of its speed due to interaction with 2D electrons in n-GaAlAs/GaAs/GaAlAs structures are measured versus perpendicular magnetic field of up to 18 T in the frequency range of (28.5 - 306) MHz and at temperatures (40 - 380) mK. The study is performed on δ-doped from both sides 65 nm wide GaAs quantum well with the carrier density of n = 5 .1010 cm-2 and their mobility of μ = 8 .106 cm2/V.s. The complex AC conductance, σ is calculated. Analysis of σ shows that at low temperatures and at the filling factor of 2, 1, and 1/5 the electron system resides in the integer and fractional quantum Hall states, respectively. However, in vicinities to these values, namely at ν = 1.9, (1.1 and 0.9), (0.21 and 0.19), the electron states can be interpreted as so-called pinning modes of Wigner crystal (WC). Temperature dependences of σ indicates a crossover between the localized modes (at ν = 1 and 2) and a pinned WC. When the temperature (or the SAW intensity) increases the behavior of the complex conductance can be understood as manifestation of WC melting. Acknowledgements to E. Palm, T. Murphy, J.-H. Park, and G. Jones; RFBR Grant 14-02-00232 for ILD; NSF DMR-1157490 and the State of Florida for NHMFL; Gordon and Betty Moore Foundation Grant GBMF2719 and NSF MRSEC-DMR-0819860 for Princeton University.

  2. Supertaster, super reactive: oral sensitivity for bitter taste modulates emotional approach and avoidance behavior in the affective startle paradigm.

    PubMed

    Herbert, Cornelia; Platte, Petra; Wiemer, Julian; Macht, Michael; Blumenthal, Terry D

    2014-08-01

    People differ in both their sensitivity for bitter taste and their tendency to respond to emotional stimuli with approach or avoidance. The present study investigated the relationship between these sensitivities in an affective picture paradigm with startle responding. Emotion-induced changes in arousal and attention (pupil modulation), priming of approach and avoidance behavior (startle reflex modulation), and subjective evaluations (ratings) were examined. Sensitivity for bitter taste was assessed with the 6-n-propylthiouracil (PROP)-sensitivity test, which discriminated individuals who were highly sensitive to PROP compared to NaCl (PROP-tasters) and those who were less sensitive or insensitive to the bitter taste of PROP. Neither pupil responses nor picture ratings differed between the two taster groups. The startle eye blink response, however, significantly differentiated PROP-tasters from PROP-insensitive subjects. Facilitated response priming to emotional stimuli emerged in PROP-tasters but not in PROP-insensitive subjects at shorter startle lead intervals (200-300ms between picture onset and startle stimulus onset). At longer lead intervals (3-4.5s between picture onset and startle stimulus onset) affective startle modulation did not differ between the two taster groups. This implies that in PROP-sensitive individuals action tendencies of approach or avoidance are primed immediately after emotional stimulus exposure. These results suggest a link between PROP taste perception and biologically relevant patterns of emotional responding. Direct perception-action links have been proposed to underlie motivational priming effects of the startle reflex, and the present results extend these to the sensory dimension of taste.

  3. Affective modulation of the startle reflex and the Reinforcement Sensitivity Theory of personality: The role of sensitivity to reward.

    PubMed

    Aluja, Anton; Blanch, Angel; Blanco, Eduardo; Balada, Ferran

    2015-01-01

    This study evaluated differences in the amplitude of startle reflex and Sensitivity to Reward (SR) and Sensitivity to Punishment (SP) personality variables of the Reinforcement Sensitivity Theory (RST). We hypothesized that subjects with higher scores in SR would obtain a higher startle reflex when exposed to pleasant pictures than lower scores, while higher scores in SP would obtain a higher startle reflex when exposed to unpleasant pictures than subjects with lower scores in this dimension. The sample consisted of 112 healthy female undergraduate psychology students. Personality was assessed using the short version of the Sensitivity to Punishment and Sensitivity Reward Questionnaire (SPSRQ). Laboratory anxiety was controlled by the State Anxiety Inventory. The startle blink reflex was recorded electromyographically (EMG) from the right orbicularis oculi muscle as a response to the International Affective Picture System (IAPS) pleasant, neutral and unpleasant pictures. Subjects higher in SR obtained a significant higher startle reflex response in pleasant pictures than lower scorers (48.48 vs 46.28, p<0.012). Subjects with higher scores in SP showed a light tendency of higher startle responses in unpleasant pictures in a non-parametric local regression graphical analysis (LOESS). The findings shed light on the relationships among the impulsive-disinhibited personality, including sensitivity to reward and emotions evoked through pictures of emotional content.

  4. Memory for objects and startle responsivity in the immediate aftermath of exposure to the Trier Social Stress Test.

    PubMed

    Herten, Nadja; Pomrehn, Dennis; Wolf, Oliver T

    2017-03-14

    Previously, we observed enhanced long-term memory for objects used (central objects) by committee members in the Trier Social Stress Test (TSST) on the next day. In addition, startle responsivity was increased. However, response specificity to an odour involved in the stressful episode was lacking and recognition memory for the odour was poor. In the current experiments, immediate effects of the stressor on memory and startle responsivity were investigated. We hypothesised memory for central objects of the stressful episode and startle response specificity to an odour ambient during the TSST to be enhanced shortly after it, in contrast to the control condition (friendly TSST). Further, memory for this odour was also assumed to be increased in the stress group. We tested 70 male (35) and female participants using the TSST involving objects and an ambient odour. After stress induction, a startle paradigm including olfactory and visual stimuli was conducted. Indeed, memory for central objects was significantly enhanced in immediate aftermath of the stressor. Startle responsivity increased at a trend level, particularly with regard to the odour involved in the stressful episode. Moreover, the stress group descriptively tended towards a better recognition of the odour involved. The study shows that stress enhances memory for central aspects of a stressful situation before consolidation processes come into play. In addition, results preliminarily suggest that the impact of stress on startle responsivity increases in strength but decreases in specificity during the first 24h after stress exposure.

  5. Successful epilepsy surgery in frontal lobe epilepsy with startle seizures: a SEEG study.

    PubMed

    Ciurea, Ana; Popa, Irina; Maliia, Mihai Dragos; Csilla-Johanna, Nagy; Barborica, Andrei; Donos, Cristian; Ciurea, Jean; Opris, Ioan; Mindruta, Ioana

    2015-12-01

    Pre-surgical assessment and surgical management of frontal epilepsy with normal MRI is often challenging. We present a case of a 33-year-old, right-handed, educated male. During childhood, his seizures presented with mandibular myoclonus and no particular trigger. As a young adult, he developed seizures with a startle component, triggered by unexpected noises. During his ictal episodes, he felt fear and grimaced with sudden head flexion and tonic axial posturing. Similar seizures also occurred without startle. Neuropsychological assessment showed executive dysfunction and verbal memory deficit. The cerebral MRI was normal. Electro-clinical reasoning, investigations performed, the results obtained and follow-up are discussed in detail. [Published with video sequence].

  6. Fear potentiated startle at short intervals following conditioned stimulus onset during delay but not trace conditioning.

    PubMed

    Asli, Ole; Kulvedrøsten, Silje; Solbakken, Line E; Flaten, Magne Arve

    2009-07-01

    The latency of conditioned fear after delay and trace conditioning was investigated. Some argue that delay conditioning is not dependent on awareness. In contrast, trace conditioning, where there is a gap between the conditioned stimulus (CS) and the unconditioned stimulus (US), is assumed to be dependent on awareness. In the present study, a tone CS signaled a noise US presented 1000 ms after CS onset in the delay conditioning group. In the trace conditioning group, a 200-ms tone CS was followed by an 800-ms gap prior to US presentation. Fear-potentiated startle should be seen at shorter intervals after delay conditioning compared to trace conditioning. Analyses showed increased startle at 30, 50, 100, and 150 ms after CS onset following delay conditioning compared to trace conditioning. This implies that fear-relevant stimuli elicit physiological reactions before extended processing of the stimuli occur, following delay, but not trace conditioning.

  7. Protective balance and startle responses to sudden freefall in standing humans.

    PubMed

    Sanders, Ozell P; Savin, Douglas N; Creath, Robert A; Rogers, Mark W

    2015-01-23

    The aim of the present study was to investigate whether or not startle reactions contribute to the whole body postural responses following sudden freefall in standing humans. Nine healthy participants stood atop a moveable platform and received externally-triggered (EXT) and selftriggered (SLF) drop perturbations of the support surface. Electromyographic (EMG) activity was recorded bilaterally over the sternocleidomastoid (SCM), deltoid (DLT), biceps brachii (BIC), medial gastrocnemius (GAS), and tibialis anterior (TA) muscles. Whole-body kinematics were also recorded with motion analysis. Rapid phasic activation of SCM during the first trial response (FTR) was seen for all participants for EXT and for 56% of subjects for SLF. Reductions in EMG amplitude between the EXT FTR and later trial responses for SCM, DLT, and BIC and reduced arm movement acceleration indicative of habituation occurred and exceeded adaptive reductions for SLF. These findings suggested that a startle reflex contributes to the exaggerated postural FTR observed during externally-triggered whole-body free falls.

  8. COMMUNALITIES AND DIFFERENCES IN FEAR POTENTIATION BETWEEN CARDIAC DEFENSE AND EYE-BLINK STARTLE

    PubMed Central

    Sánchez, María B.; Guerra, Pedro; Muñoz, Miguel A.; Mata, José Luís; Bradley, Margaret M.; Lang, Peter J.; Vila, Jaime

    2009-01-01

    This study examines similarities and differences in fear potentiation between two protective reflexes: cardiac defense and eye-blink startle. Women reporting intense fear of animals but low fear of blood or intense fear of blood but low fear of animals viewed pictures depicting blood or the feared animal for 6 s in 2 separate trials in counterbalanced order. An intense burst of white noise, able to elicit both a cardiac defense response and a reflexive startle blink, was presented 3.5 s after picture onset. Both cardiac and blink responses were potentiated when highly fearful individuals viewed fearful pictures. However, differences appeared concerning picture order. This pattern of results indicates communalities and differences among protective reflexes that are relevant for understanding the dynamics of emotional reflex modulation. PMID:19572906

  9. The human startle reflex and alcohol cue reactivity: effects of early versus late abstinence.

    PubMed

    Saladin, Michael E; Drobes, David J; Coffey, Scott F; Libet, Julian M

    2002-06-01

    This study investigated the human eyeblink startle reflex as a measure of alcohol cue reactivity. Alcohol-dependent participants early (n = 36) and late (n = 34) in abstinence received presentations of alcohol and water cues. Consistent with previous research, greater salivation and higher ratings of urge to drink occurred in response to the alcohol cues. Differential salivary and urge responding to alcohol versus water cues did not vary as a function of abstinence duration. Of special interest was the finding that startle response magnitudes were relatively elevated to alcohol cues, but only in individuals early in abstinence. Affective ratings of alcohol cues suggested that alcohol cues were perceived as aversive. Methodological and theoretical implications of the findings are discussed.

  10. Acoustical Measurement Of Furnace Temperatures

    NASA Technical Reports Server (NTRS)

    Parthasarathy, Shakkottai; Venkateshan, Shakkottai P.

    1989-01-01

    Simple probes withstand severe conditions, yet give spatially-resolved temperature readings. Prototype acoustical system developed to measure temperatures from ambient to 1,800 degree F in such structures as large industrial lime kilns and recovery-boiler furnaces. Pulses of sound reflected from obstructions in sensing tube. Speed of sound and temperature in each segment deduced from travel times of pulses.

  11. The Mauthner-cell circuit of fish as a model system for startle plasticity.

    PubMed

    Medan, Violeta; Preuss, Thomas

    2014-01-01

    The Mauthner-cell (M-cell) system of teleost fish has a long history as an experimental model for addressing a wide range of neurobiological questions. Principles derived from studies on this system have contributed significantly to our understanding at multiple levels, from mechanisms of synaptic transmission and synaptic plasticity to the concepts of a decision neuron that initiates key aspects of the startle behavior. Here we will review recent work that focuses on the neurophysiological and neuropharmacological basis for modifications in the M-cell circuit. After summarizing the main excitatory and inhibitory inputs to the M-cell, we review experiments showing startle response modulation by temperature, social status, and sensory filtering. Although very different in nature, actions of these three sources of modulation converge in the M-cell network. Mechanisms of modulation include altering the excitability of the M-cell itself as well as changes in excitatory and inhibitor drive, highlighting the role of balanced excitation and inhibition for escape decisions. One of the most extensively studied forms of startle plasticity in vertebrates is prepulse inhibition (PPI), a sensorimotor gating phenomenon, which is impaired in several information processing disorders. Finally, we review recent work in the M-cell system which focuses on the cellular mechanisms of PPI and its modulation by serotonin and dopamine.

  12. Musical Acoustics

    NASA Astrophysics Data System (ADS)

    Gough, Colin

    This chapter provides an introduction to the physical and psycho-acoustic principles underlying the production and perception of the sounds of musical instruments. The first section introduces generic aspects of musical acoustics and the perception of musical sounds, followed by separate sections on string, wind and percussion instruments.

  13. Acoustic absorption by sunspots

    NASA Technical Reports Server (NTRS)

    Braun, D. C.; Labonte, B. J.; Duvall, T. L., Jr.

    1987-01-01

    The paper presents the initial results of a series of observations designed to probe the nature of sunspots by detecting their influence on high-degree p-mode oscillations in the surrounding photosphere. The analysis decomposes the observed oscillations into radially propagating waves described by Hankel functions in a cylindrical coordinate system centered on the sunspot. From measurements of the differences in power between waves traveling outward and inward, it is demonstrated that sunspots appear to absorb as much as 50 percent of the incoming acoustic waves. It is found that for all three sunspots observed, the amount of absorption increases linearly with horizontal wavenumber. The effect is present in p-mode oscillations with wavelengths both significantly larger and smaller than the diameter of the sunspot umbrae. Actual absorption of acoustic energy of the magnitude observed may produce measurable decreases in the power and lifetimes of high-degree p-mode oscillations during periods of high solar activity.

  14. Unilateral block of NMDA receptors in the amygdala prevents predator stress-induced lasting increases in anxiety-like behavior and unconditioned startle--effective hemisphere depends on the behavior.

    PubMed

    Adamec, R E; Burton, P; Shallow, T; Budgell, J

    Lasting increases in anxiety-like behavior (ALB) in the elevated plus-maze are produced by a single 5-min exposure of a rat to a cat. Rats become more anxious in the plus-maze for up to 3 weeks after the exposure. The first study in this series demonstrated that blockade of NMDA receptors in rats with MK-801, AP7, or CPP, given systemically 30 min prior to exposure to a cat prevents the increase in ALB assessed 1 week later in the elevated plus-maze. To localize the site of action of systemic MK-801, MK-801 was injected in the amygdala 30 min prior to predator stress. Injections were given either unilaterally in either hemisphere, or bilaterally in both hemispheres. The target of the injection was the basolateral amygdala. The effects of injection depended on both the type of behavior and the hemisphere of injection. Injections of MK-801 in a variety of sites in the basolateral amygdala had no effect on the suppression of open-arm exploration produced by predator stress. Other amygdala nuclei or other limbic sites likely mediate the effects of systemically administered MK-801 on this behavior. In contrast, NMDA receptors in the left lateral amygdala mediate lasting suppression of risk assessment. MK-801, in a variety of sites in the left but not right lateral amygdala, blocked the effects of predator stress on risk assessment. This is clear evidence of separability of neural mechanisms controlling open-arm exploration and risk assessment. Different NMDA-dependent amygdala circuitry mediated effects of predator stress on unconditioned acoustic startle 1 week after cat exposure. The data indicate that integrity of the left lateral amygdala is necessary for potentiation of startle amplitude by predator stress, though NMDA receptors are not involved in this function. Nevertheless, NMDA receptors in the right, but not the left lateral amygdala, mediate initiation of changes in startle. The data also suggest that the right amygdala action is "downstream" from the left

  15. Room Acoustics

    NASA Astrophysics Data System (ADS)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  16. How many blinks are necessary for a reliable startle response? A test using the NPU-threat task.

    PubMed

    Lieberman, Lynne; Stevens, Elizabeth S; Funkhouser, Carter J; Weinberg, Anna; Sarapas, Casey; Huggins, Ashley A; Shankman, Stewart A

    2017-04-01

    Emotion-modulated startle is a frequently used method in affective science. Although there is a growing literature on the reliability of this measure, it is presently unclear how many startle responses are necessary to obtain a reliable signal. The present study therefore evaluated the reliability of startle responding as a function of number of startle responses (NoS) during a widely used threat-of-shock paradigm, the NPU-threat task, in a clinical (N=205) and non-clinical (N=92) sample. In the clinical sample, internal consistency was also examined independently for healthy controls vs. those with panic disorder and/or major depression and retest reliability was assessed as a function of NoS. Although results varied somewhat by diagnosis and for retest reliability, the overall pattern of results suggested that six startle responses per condition were necessary to obtain acceptable reliability in clinical and non-clinical samples during this threat-of-shock paradigm in the present study.

  17. Emotional effects of startling background music during reading news reports: The moderating influence of dispositional BIS and BAS sensitivities.

    PubMed

    Ravaja, Niklas; Kallinen, Kari

    2004-07-01

    We examined the moderating influence of dispositional behavioral inhibition system (BIS) and behavioral activation system (BAS) sensitivities on the relationship of startling background music with emotion-related subjective and physiological responses elicited during reading news reports, and with memory performance among 26 adult men and women. Physiological parameters measured were respiratory sinus arrhythmia (RSA), electrodermal activity (EDA), and facial electromyography (EMG). The results showed that, among high BAS individuals, news stories with startling background music were rated as more interesting and elicited higher zygomatic EMG activity and RSA than news stories with non-startling music. Among low BAS individuals, news stories with startling background music were rated as less pleasant and more arousing and prompted higher EDA. No BIS-related effects or effects on memory were found. Startling background music may have adverse (e.g., negative arousal) or beneficial effects (e.g., a positive emotional state and stronger positive engagement) depending on dispositional BAS sensitivity of an individual. Actual or potential applications of this research include the personalization of media presentations when using modern media and communications technologies.

  18. Sleep deprivation disrupts prepulse inhibition of the startle reflex: reversal by antipsychotic drugs.

    PubMed

    Frau, Roberto; Orrù, Marco; Puligheddu, Monica; Gessa, Gian Luigi; Mereu, Giampaolo; Marrosu, Francesco; Bortolato, Marco

    2008-11-01

    Sleep deprivation (SD) is known to induce perceptual impairments, ranging from perceptual distortion to hallucinatory states. Although this phenomenon has been extensively described in the literature, its neurobiological underpinnings remain elusive. In rodents, SD induces a series of behavioural patterns that might be reflective of psychosis and mania, such as hyperlocomotion and sensitization to psychotogenic drugs. Notably, such changes are accompanied by transitory alterations of dopaminergic signalling. Based on the hypothesis that both psychotic and manic disorders reflect gating impairments, the present study was aimed at the assessment of the impact of SD on the behavioural model of prepulse inhibition (PPI) of the startle reflex, a reliable paradigm for the study of informational filtering. Rats subjected to SD (24 h, 48 h, 72 h) exhibited a time-dependent increase in startle reflex and a dramatic deficit in PPI. Both alterations were reversed 24 h after termination of the SD period. Interestingly, PPI disruption was efficiently prevented by haloperidol (0.1 mg/kg i.p.) clozapine (5 mg/kg i.p.) and risperidone (1 mg/kg i.p.). Conversely, neither the anxiolytic diazepam (5 mg/kg i.p.) nor the antidepressant citalopram (5 mg/kg i.p) affected the PPI disruption mediated by SD, although diazepam reversed the enhancement in startle reflex magnitude induced by this manipulation. Our data suggest that SD induces gating deficits that might be relevant to the hallucinatory phenomena observed in humans, and provide a novel reliable animal model where such relationship can be studied.

  19. Murine startle mutant Nmf11 affects the structural stability of the glycine receptor and increases deactivation

    PubMed Central

    Wilkins, Megan E.; Caley, Alex; Gielen, Marc C.; Harvey, Robert J.

    2016-01-01

    Key points Hyperekplexia or startle disease is a serious neurological condition affecting newborn children and usually involves dysfunctional glycinergic neurotransmission.Glycine receptors (GlyRs) are major mediators of inhibition in the spinal cord and brainstem.A missense mutation, replacing asparagine (N) with lysine (K), at position 46 in the GlyR α1 subunit induced hyperekplexia following a reduction in the potency of the transmitter glycine; this resulted from a rapid deactivation of the agonist current at mutant GlyRs.These effects of N46K were rescued by mutating a juxtaposed residue, N61 on binding Loop D, suggesting these two asparagines may interact.Asparagine 46 is considered to be important for the structural stability of the subunit interface and glycine binding site, and its mutation represents a new mechanism by which GlyR dysfunction induces startle disease. Abstract Dysfunctional glycinergic inhibitory transmission underlies the debilitating neurological condition, hyperekplexia, which is characterised by exaggerated startle reflexes, muscle hypertonia and apnoea. Here we investigated the N46K missense mutation in the GlyR α1 subunit gene found in the ethylnitrosourea (ENU) murine mutant, Nmf11, which causes reduced body size, evoked tremor, seizures, muscle stiffness, and morbidity by postnatal day 21. Introducing the N46K mutation into recombinant GlyR α1 homomeric receptors, expressed in HEK cells, reduced the potencies of glycine, β‐alanine and taurine by 9‐, 6‐ and 3‐fold respectively, and that of the competitive antagonist strychnine by 15‐fold. Replacing N46 with hydrophobic, charged or polar residues revealed that the amide moiety of asparagine was crucial for GlyR activation. Co‐mutating N61, located on a neighbouring β loop to N46, rescued the wild‐type phenotype depending on the amino acid charge. Single‐channel recording identified that burst length for the N46K mutant was reduced and fast agonist application

  20. EnEx-RANGE - Robust autonomous Acoustic Navigation in Glacial icE

    NASA Astrophysics Data System (ADS)

    Heinen, Dirk; Eliseev, Dmitry; Henke, Christoph; Jeschke, Sabina; Linder, Peter; Reuter, Sebastian; Schönitz, Sebastian; Scholz, Franziska; Weinstock, Lars Steffen; Wickmann, Stefan; Wiebusch, Christopher; Zierke, Simon

    2017-03-01

    Within the Enceladus Explorer Initiative of the DLR Space Administration navigation technologies for a future space mission are in development. Those technologies are the basis for the search for extraterrestrial life on the Saturn moon Enceladus. An autonomous melting probe, the EnEx probe, aims to extract a liquid sample from a water reservoir below the icy crust. A first EnEx probe was developed and demonstrated in a terrestrial scenario at the Bloodfalls, Taylor Glacier, Antarctica in November 2014. To enable navigation in glacier ice two acoustic systems were integrated into the probe in addition to conventional navigation technologies. The first acoustic system determines the position of the probe during the run based on propagation times of acoustic signals from emitters at reference positions at the glacier surface to receivers in the probe. The second system provides information about the forefield of the probe. It is based on sonographic principles with phased array technology integrated in the probe's melting head. Information about obstacles or sampling regions in the probe's forefield can be acquired. The development of both systems is now continued in the project EnEx-RANGE. The emitters of the localization system are replaced by a network of intelligent acoustic enabled melting probes. These localize each other by means of acoustic signals and create the reference system for the EnEx probe. This presentation includes the discussion of the intelligent acoustic network, the acoustic navigation systems of the EnEx probe and results of terrestrial tests.

  1. Affect-modulated startle: interactive influence of catechol-O-methyltransferase Val158Met genotype and childhood trauma.

    PubMed

    Klauke, Benedikt; Winter, Bernward; Gajewska, Agnes; Zwanzger, Peter; Reif, Andreas; Herrmann, Martin J; Dlugos, Andrea; Warrings, Bodo; Jacob, Christian; Mühlberger, Andreas; Arolt, Volker; Pauli, Paul; Deckert, Jürgen; Domschke, Katharina

    2012-01-01

    The etiology of emotion-related disorders such as anxiety or affective disorders is considered to be complex with an interaction of biological and environmental factors. Particular evidence has accumulated for alterations in the dopaminergic and noradrenergic system--partly conferred by catechol-O-methyltransferase (COMT) gene variation--for the adenosinergic system as well as for early life trauma to constitute risk factors for those conditions. Applying a multi-level approach, in a sample of 95 healthy adults, we investigated effects of the functional COMT Val158Met polymorphism, caffeine as an adenosine A2A receptor antagonist (300 mg in a placebo-controlled intervention design) and childhood maltreatment (CTQ) as well as their interaction on the affect-modulated startle response as a neurobiologically founded defensive reflex potentially related to fear- and distress-related disorders. COMT val/val genotype significantly increased startle magnitude in response to unpleasant stimuli, while met/met homozygotes showed a blunted startle response to aversive pictures. Furthermore, significant gene-environment interaction of COMT Val158Met genotype with CTQ was discerned with more maltreatment being associated with higher startle potentiation in val/val subjects but not in met carriers. No main effect of or interaction effects with caffeine were observed. Results indicate a main as well as a GxE effect of the COMT Val158Met variant and childhood maltreatment on the affect-modulated startle reflex, supporting a complex pathogenetic model of the affect-modulated startle reflex as a basic neurobiological defensive reflex potentially related to anxiety and affective disorders.

  2. Acoustic temperature measurement in a rocket noise field.

    PubMed

    Giraud, Jarom H; Gee, Kent L; Ellsworth, John E

    2010-05-01

    A 1 μm diameter platinum wire resistance thermometer has been used to measure temperature fluctuations generated during a static GEM-60 rocket motor test. Exact and small-signal relationships between acoustic pressure and acoustic temperature are derived in order to compare the temperature probe output with that of a 3.18 mm diameter condenser microphone. After preliminary plane wave tests yielded good agreement between the transducers within the temperature probe's ∼2 kHz bandwidth, comparison between the temperature probe and microphone data during the motor firing show that the ±∼3 K acoustic temperature fluctuations are a significant contributor to the total temperature variations.

  3. Acoustic biosensors

    PubMed Central

    Fogel, Ronen; Seshia, Ashwin A.

    2016-01-01

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. PMID:27365040

  4. Acoustic biosensors.

    PubMed

    Fogel, Ronen; Limson, Janice; Seshia, Ashwin A

    2016-06-30

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors.

  5. Turbofan aft duct suppressor study. Contractor's data report of mode probe signal data

    NASA Technical Reports Server (NTRS)

    Fiske, G. H.; Motsinger, R. E.; Syed, A. A.; Joshi, M. C.; Kraft, R. E.

    1983-01-01

    Acoustic modal distributions were measured in a fan test model having an annular exhaust duct for comparison with theoretically predicted acoustic suppression values. This report contains the amplitude and phase data of the acoustic signals sensed by the transducers of the two mode probes employed in the measurement. Each mode probe consisted of an array of 12 transducers sensing the acoustic field at three axial positions and four radial positions.

  6. Clarifying the Role of Defensive Reactivity Deficits in Psychopathy and Antisocial Personality Using Startle Reflex Methodology

    PubMed Central

    Vaidyanathan, Uma; Hall, Jason R.; Patrick, Christopher J.; Bernat, Edward M.

    2010-01-01

    Prior research has demonstrated deficits in defensive reactivity (indexed by potentiation of the startle blink reflex) in psychopathic individuals. However, the basis of this association remains unclear, as diagnostic criteria for psychopathy encompass two distinct phenotypic components that may reflect differing neurobiological mechanisms – an affective-interpersonal component, and an antisocial deviance component. Likewise, the role of defensive response deficits in antisocial personality disorder (APD), a related but distinct syndrome, remains to be clarified. The current study examined affective priming deficits in relation to factors of psychopathy and symptoms of APD using startle reflex methods in 108 adult male prisoners. Deficits in blink reflex potentiation during aversive picture viewing were found in relation to the affective-interpersonal (Factor 1) component of psychopathy, and to a lesser extent in relation to the antisocial deviance (Factor 2) component of psychopathy and symptoms of APD—but only as a function of their overlap with affective-interpersonal features of psychopathy. These findings provide clear evidence that deficits in defensive reactivity are linked specifically to the affective-interpersonal features of psychopathy, and not the antisocial deviance features represented most strongly in APD. PMID:20973594

  7. Neurological effects on startle response and escape from predation by medaka exposed to organic chemicals

    SciTech Connect

    Carlson, R.; Drummond, R.; Hammermeister, D.; Bradbury, S.

    1995-12-31

    Simultaneous electrophysiological and behavioral studies were performed on juvenile Japanese medaka (Oryzias latipes) exposed to representative neurotoxic organic chemicals at sublethal concentrations. Non-invasive recordings were made of the electrical impulses generated within giant neuronal Mauthner cells, associated interneurons or motoneurons, and musculature, all of which initiate the startle or escape response in fish. Timing in milliseconds between these electrical sequelae was measured for each fish before and at 24 and 48 hours exposure to a chemical. Also noted was the number of startle responses to number of stimuli ratio (R/S). Other groups of medaka were fed to bluegills and consumption times recorded to assess their ability to escape predation. These results were compared to neurophysiological effect levels. Phenol, 2,4-dinitrophenol, chlorpyrifos, fenvalerate, and 1-octanol impaired the ability of medaka to escape predation at all concentrations. Medaka were more susceptible to predation in high concentrations of carbaryl and strychnine, but less susceptible at low concentrations, whereas the reverse was true for endosulfan. The variety of neurological effects detected at these concentrations suggest that different mechanisms may be responsible. Phenol and strychnine affected Mauthner cell to motoneuron transmission, chlorpyrifos and carbaryl showed neuromuscular effects, and R/S was affected by most chemicals. Although a variety of neurotoxic mechanisms were examined, the exposure threshold for significant effects for each specific compound was found to be consistent for both the neurophysiological and behavioral endpoints.

  8. Aversive startle potentiation and fear pathology: Mediating role of threat sensitivity and moderating impact of depression.

    PubMed

    Yancey, James R; Vaidyanathan, Uma; Patrick, Christopher J

    2015-11-01

    Enhanced startle reactivity during exposure to unpleasant cues (aversive startle potentiation; ASP) appears in the RDoC matrix as a physiological index of acute threat response. Increased ASP has been linked to focal fear disorders and to scale measures of dispositional fearfulness (i.e., threat sensitivity; THT+). However, some studies have reported reduced ASP for fear pathology accompanied by major depressive disorder (MDD) or pervasive distress. The current study evaluated whether (a) THT+ as indexed by reported dispositional fearfulness mediates the relationship between fear disorders (when unaccompanied by depression) and ASP, and (b) depression moderates relations of THT+ and fear disorders with ASP. Fear disorder participants without MDD showed enhanced ASP whereas those with MDD (or other distress conditions) showed evidence of reduced ASP. Continuous THT+ scores also predicted ASP, and this association: (a) was likewise moderated by depression/distress, and (b) accounted for the relationship between ASP and fear pathology without MDD. These findings point to a role for the RDoC construct of acute threat, operationalized dispositionally, in enhanced ASP shown by individuals with fear pathology unaccompanied by distress pathology.

  9. Clarifying the role of defensive reactivity deficits in psychopathy and antisocial personality using startle reflex methodology.

    PubMed

    Vaidyanathan, Uma; Hall, Jason R; Patrick, Christopher J; Bernat, Edward M

    2011-02-01

    Prior research has demonstrated deficits in defensive reactivity (indexed by potentiation of the startle blink reflex) in psychopathic individuals. However, the basis of this association remains unclear, as diagnostic criteria for psychopathy encompass two distinct phenotypic components that may reflect differing neurobiological mechanisms-an affective-interpersonal component and an antisocial deviance component. Likewise, the role of defensive response deficits in antisocial personality disorder (APD), a related but distinct syndrome, remains to be clarified. In the current study, the authors examined affective priming deficits in relation to factors of psychopathy and symptoms of APD using startle reflex methods in 108 adult male prisoners. Deficits in blink reflex potentiation during aversive picture viewing were found in relation to the affective-interpersonal (Factor 1) component of psychopathy, and to a lesser extent in relation to the antisocial deviance (Factor 2) component of psychopathy and symptoms of APD-but only as a function of their overlap with affective-interpersonal features of psychopathy. These findings provide clear evidence that deficits in defensive reactivity are linked specifically to the affective-interpersonal features of psychopathy and not to the antisocial deviance features represented most strongly in APD.

  10. Interactions of Stress and Nicotine on Amplitude, Pre-Pulse Inhibition and Habituation of the Acoustic Startle Reflex

    DTIC Science & Technology

    1992-09-24

    stress. " Hans Selye (1973 ) Cigarette smoking is the most preventable environmental factor contributing to illness and death in the United States...following noise stress on an auditory vigilance task. A possible explanation has been offered by Eysenck (1973) for some of the inconsistent...effects of nicotine on stress reduction . Eysenck (1973) argued that discordant effects can be accounted for when the effects of the organism ’ s initial

  11. The Acoustic Startle Response and Disruption of Aiming. 1. Effect of Stimulus Repetition, Intensity, and Intensity Changes

    DTIC Science & Technology

    1989-11-01

    PEST consisting of an approximate one-third oc- procedure described by Taylor and Creelman tave band centered at 800 Hz (cutoffs at 700 (1967...to some extent Taylor, M. M., and Creelman . C. D. (1967). PEST: Efficient estimates on probability functions. Journal of the performance disruption

  12. Variation in acoustic overstimulation changes tinnitus characteristics.

    PubMed

    Kiefer, L; Schauen, A; Abendroth, S; Gaese, B H; Nowotny, M

    2015-12-03

    Tinnitus often occurs after exposure to loud noise. This raises the question of whether repeated exposure to noise increases the risk of developing tinnitus. We thus studied tinnitus development after repeated acoustic overstimulation using startle and auditory brainstem-response techniques applied to Mongolian gerbils. Noise with bandwidths ranging from 0.25 up to 0.5 oct were used for repeated acoustic overstimulation. Auditory brainstem response measurements revealed similar threshold shifts in both groups of up to about 30 dB directly after the acoustic overstimulation. We identified an upper limit in threshold values, which was independent of the baseline values before the noise exposure. Several weeks after the acoustic overstimulation, animals with the noise bandwidth of 0.25 oct showed a permanent threshold shift, while animals of the group with the 0.5-oct noise band featured only a temporary threshold shift. We thus conclude that the threshold shift directly after noise exposure cannot be used as an indicator for the upcoming threshold level several weeks later. By using behavioral measurements, we investigated the frequency-dependent development of tinnitus-related changes in both groups and one group with 1-oct noise bandwidth. The number of animals that show tinnitus-related changes was highest in animals that received noise with the bandwidth 0.5 oct. This number was, in contrast to the number of animals in the 0.25-oct bandwidth, not significantly increased after repeated overstimulation. The frequency distribution of tinnitus-related changes ranged from 4 to 20 kHz. In the group with the narrow-band noise (0.25 oct) changes center at one frequency range from 10 to 12 kHz. In the group with the broader noise band (0.5 oct), however, two peaks at 8-10 kHz and at 16-18 kHz were found, which suggests that different mechanisms underlie the tinnitus development.

  13. Nonlinear Acoustics

    DTIC Science & Technology

    1974-02-14

    Wester- velt. [60] Streaming. In 1831, Michael Faraday [61] noted that currents of air were set up in the neighborhood of vibrating plates-the first... ducei in the case of a paramettc amy (from Berktay an Leahy 141). C’ "". k•, SEC 10.1 NONLINEAR ACOUSTICS 345 The principal results of their analysis

  14. Contextual-Specificity of Short-Delay Extinction in Humans: Renewal of Fear-Potentiated Startle in a Virtual Environment

    ERIC Educational Resources Information Center

    Alvarez, Ruben P.; Johnson, Linda; Grillon, Christian

    2007-01-01

    A recent fear-potentiated startle study in rodents suggested that extinction was not context dependent when extinction was conducted after a short delay following acquisition, suggesting that extinction can lead to erasure of fear learning in some circumstances. The main objective of this study was to attempt to replicate these findings in humans…

  15. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, Butrus T.; Chou, Ching H.

    1990-01-01

    A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

  16. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, B.T.; Chou, C.H.

    1990-03-20

    A shear acoustic transducer-lens system is described in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens. 9 figs.

  17. Proteomics tools reveal startlingly high amounts of oxytocin in plasma and serum

    PubMed Central

    Brandtzaeg, Ole Kristian; Johnsen, Elin; Roberg-Larsen, Hanne; Seip, Knut Fredrik; MacLean, Evan L.; Gesquiere, Laurence R.; Leknes, Siri; Lundanes, Elsa; Wilson, Steven Ray

    2016-01-01

    The neuropeptide oxytocin (OT) is associated with a plethora of social behaviors, and is a key topic at the intersection of psychology and biology. However, tools for measuring OT are still not fully developed. We describe a robust nano liquid chromatography-mass spectrometry (nanoLC-MS) platform for measuring the total amount of OT in human plasma/serum. OT binds strongly to plasma proteins, but a reduction/alkylation (R/A) procedure breaks this bond, enabling ample detection of total OT. The method (R/A + robust nanoLC-MS) was used to determine total OT plasma/serum levels to startlingly high concentrations (high pg/mL-ng/mL). Similar results were obtained when combining R/A and ELISA. Compared to measuring free OT, measuring total OT can have advantages in e.g. biomarker studies. PMID:27528413

  18. Proteomics tools reveal startlingly high amounts of oxytocin in plasma and serum

    NASA Astrophysics Data System (ADS)

    Brandtzaeg, Ole Kristian; Johnsen, Elin; Roberg-Larsen, Hanne; Seip, Knut Fredrik; Maclean, Evan L.; Gesquiere, Laurence R.; Leknes, Siri; Lundanes, Elsa; Wilson, Steven Ray

    2016-08-01

    The neuropeptide oxytocin (OT) is associated with a plethora of social behaviors, and is a key topic at the intersection of psychology and biology. However, tools for measuring OT are still not fully developed. We describe a robust nano liquid chromatography-mass spectrometry (nanoLC-MS) platform for measuring the total amount of OT in human plasma/serum. OT binds strongly to plasma proteins, but a reduction/alkylation (R/A) procedure breaks this bond, enabling ample detection of total OT. The method (R/A + robust nanoLC-MS) was used to determine total OT plasma/serum levels to startlingly high concentrations (high pg/mL-ng/mL). Similar results were obtained when combining R/A and ELISA. Compared to measuring free OT, measuring total OT can have advantages in e.g. biomarker studies.

  19. Spectrophotometric probe

    DOEpatents

    Prather, W.S.; O'Rourke, P.E.

    1994-08-02

    A support structure is described bearing at least one probe for making spectrophotometric measurements of a fluid using a source of light and a spectrophotometer. The probe includes a housing with two optical fibers and a planoconvex lens. A sleeve bearing a mirror surrounds the housing. The lens is separated from the mirror by a fixed distance, defining an interior space for receiving a volume of the fluid sample. A plurality of throughholes extending through the sleeve communicate between the sample volume and the exterior of the probe, all but one hole bearing a screen. A protective jacket surrounds the probe. A hollow conduit bearing a tube is formed in the wall of the probe for venting any air in the interior space when fluid enters. The probe is held at an acute angle so the optic fibers carrying the light to and from the probe are not bent severely on emergence from the probe. 3 figs.

  20. Spectrophotometric probe

    DOEpatents

    Prather, William S.; O'Rourke, Patrick E.

    1994-01-01

    A support structure bearing at least one probe for making spectrophotometric measurements of a fluid using a source of light and a spectrophotometer. The probe includes a housing with two optical fibers and a planoconvex lens. A sleeve bearing a mirror surrounds the housing. The lens is separated from the mirror by a fixed distance, defining an interior space for receiving a volume of the fluid sample. A plurality of throughholes extending through the sleeve communicate between the sample volume and the exterior of the probe, all but one hole bearing a screen. A protective jacket surrounds the probe. A hollow conduit bearing a tube is formed in the wall of the probe for venting any air in the interior space when fluid enters. The probe is held at an acute angle so the optic fibers carrying the light to and from the probe are not bent severely on emergence from the probe.

  1. Comparison of vestibular and auditory startle responses in the rat and cat.

    PubMed

    Gruner, J A

    1989-02-01

    Cats, humans, and many other animals show stereotyped EMG responses in limb and axial muscles if suddenly dropped into free-fall. In cats, these free-fall responses (FFR) consist of highly synchronized bursts in most limb and axial muscles at 18-22 ms. We have used FFR to evaluate descending motor function and recovery in chronic spinal injured cats. Here FFR are compared with auditory evoked startle reflexes (ASR) in the hindlimb muscles of the rat and cat to determine whether they are related, and whether they could be used to evaluate descending motor function in the rat. ASR and FFR in the two species were similar except that the earliest components for both responses occurred around 9 ms in the rat versus 18-20 ms in the cat. Also, FFR in cats were usually more consistent and greater in amplitude during repeated drops than in rats, while the converse was true for ASR. Rat FFR amplitudes increased significantly after administering ketamine or 4-aminopyridine (4-AP), especially with both drugs together, while ASR amplitudes did not. FFR in cats recorded under ketamine analgesia were not normally improved by 4-AP. Finally, both FFR and ASR were suppressed by pentobarbital, chloralose, or motor activity. These data suggest that: (1) FFR appears to be a vestibular evoked startle reflex; (2) in the rat, ASR should be useful as a test of descending motor function following spinal injury, and (3) the combination of ketamine and 4-AP may be useful in revealing the presence of functional spinal pathways after CNS trauma.

  2. Reduction of fear-potentiated startle by benzodiazepines in C57BL/6J mice

    PubMed Central

    Smith, Kiersten S.; Meloni, Edward G.; Myers, Karyn M.; Veer, Ashlee Van't; Carlezon, William A.; Rudolph, Uwe

    2011-01-01

    Rationale Anxiety disorders affect 18% of the United States adult population annually. Recent surges in the diagnosis of posttraumatic stress disorder (PTSD) from combat-exposed veterans have prompted an urgent need to understand the pathophysiology underlying this debilitating condition. Objectives Anxiety and fear responses are partly modulated by gamma aminobutyric acid type A (GABAA) receptor-mediated synaptic inhibition; benzodiazepines potentiate GABAergic inhibition and are effective anxiolytics. Many genetically modified mouse lines are generated and/or maintained on the C57BL/6J background, a strain where manipulation of anxiety-like behavior using benzodiazepines is difficult. Fear-potentiated startle (FPS), a test of conditioned fear, is a useful preclinical tool to study PTSD-like responses but has been difficult to establish in C57BL/6J mice. Methods We modified several FPS experimental parameters and developed a paradigm to assess conditioned fear in C57BL/6J mice. The 6-day protocol consisted of three startle Acclimation days, a Pre-Test day followed by Training and Testing for FPS. Subject responses to the effects of three benzodiazepines were also examined. Results C57BL/6J mice had low levels of unconditioned fear assessed during Pre-Test (15–18%) but showed robust FPS (80–120%) during the Test session. Conditioned fear responses extinguished over repeated test sessions. Administration of the benzodiazepines alprazolam (0.5 and 1 mg/kg, i.p.), chlordiazepoxide (5 and 10 mg/kg, i.p.), and diazepam (1, 2, and 4 mg/kg, i.p.) significantly reduced FPS to Pre-Test levels. Conclusions We used a modified and pharmacologically-validated paradigm to assess FPS in mice thereby providing a powerful tool to examine the neurobiology of PTSD in genetic models of anxiety generated on the C57BL/6J background. PMID:20922362

  3. Acoustic chaos

    SciTech Connect

    Lauterborn, W.; Parlitz, U.; Holzfuss, J.; Billo, A.; Akhatov, I.

    1996-06-01

    Acoustic cavitation, a complex, spatio-temporal dynamical system, is investigated with respect to its chaotic properties. The sound output, the {open_quote}{open_quote}noise{close_quote}{close_quote}, is subjected to time series analysis. The spatial dynamics of the bubble filaments is captured by high speed holographic cinematography and subsequent digital picture processing from the holograms. Theoretical models are put forward for describing the pattern formation. {copyright} {ital 1996 American Institute of Physics.}

  4. Medical Acoustics

    NASA Astrophysics Data System (ADS)

    Beach, Kirk W.; Dunmire, Barbrina

    Medical acoustics can be subdivided into diagnostics and therapy. Diagnostics are further separated into auditory and ultrasonic methods, and both employ low amplitudes. Therapy (excluding medical advice) uses ultrasound for heating, cooking, permeablizing, activating and fracturing tissues and structures within the body, usually at much higher amplitudes than in diagnostics. Because ultrasound is a wave, linear wave physics are generally applicable, but recently nonlinear effects have become more important, even in low-intensity diagnostic applications.

  5. Acoustic dose and acoustic dose-rate.

    PubMed

    Duck, Francis

    2009-10-01

    Acoustic dose is defined as the energy deposited by absorption of an acoustic wave per unit mass of the medium supporting the wave. Expressions for acoustic dose and acoustic dose-rate are given for plane-wave conditions, including temporal and frequency dependencies of energy deposition. The relationship between the acoustic dose-rate and the resulting temperature increase is explored, as is the relationship between acoustic dose-rate and radiation force. Energy transfer from the wave to the medium by means of acoustic cavitation is considered, and an approach is proposed in principle that could allow cavitation to be included within the proposed definitions of acoustic dose and acoustic dose-rate.

  6. Acoustic Tooth Cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.

    1984-01-01

    Acoustically-energized water jet aids in plaque breakdown. Acoustic Wand includes acoustic transducer 1/4 wave plate, and tapered cone. Together elements energize solution of water containing mild abrasive injected into mouth to help prevent calculous buildup.

  7. Nondestructive Acoustic Imaging Techniques

    NASA Astrophysics Data System (ADS)

    Schmitz, Volker

    Acoustic imaging techniques are used in the field of nondestructive testing of technical components to measure defects such as lack of side wall fusion or cracks in welded joints. Data acquisition is performed by a remote-controlled manipulator and a PC for the mass storage of the high-frequency time-of-flight data at each probe position. The quality of the acoustic images and the interpretation relies on the proper understanding of the transmitted wave fronts and the arrangement of the probes in pulse-echo mode or in pitch-and-catch arrangement. The use of the Synthetic Aperture Focusing Technique allows the depth-dependent resolution to be replaced by a depth-independent resolution and the signal-to-noise ratio to be improved. Examples with surface-connected cracks are shown to demonstrate the improved features. The localization accuracy could be improved by entering 2-dimensional or 3-dimensional reconstructed data into the environment of a 3-dimensional CAD drawing. The propagation of ultrasonic waves through austenitic welds is disturbed by the anisotropic and inhomogeneous structure of the material. The effect is more or less severe depending upon the longitudinal or shear wave modes. To optimize the performance of an inspection software tool, a 3-dimensional CAD-Ray program has been implemented, where the shape of the inhomogeneous part of a weld can be simulated together with the grain structure based on the elastic constants. Ray-tracing results are depicted for embedded and for surface-connected defects.

  8. Prediction of Acoustic Noise in Switched Reluctance Motor Drives

    SciTech Connect

    Lin, CJ; Fahimi, B

    2014-03-01

    Prediction of acoustic noise distribution generated by electric machines has become an integral part of design and control in noise sensitive applications. This paper presents a fast and precise acoustic noise imaging technique for switched reluctance machines (SRMs). This method is based on distribution of radial vibration in the stator frame of the SRM. Radial vibration of the stator frame, at a network of probing points, is computed using input phase current and phase voltage waveforms. Sequentially, the acceleration of the probing network will be expanded to predict full acceleration on the stator frame surface, using which acoustic noise emission caused by the stator can be calculated using the boundary element method.

  9. Self-report and startle-based measures of emotional reactions to body image cues as predictors of Drive for Thinness and Body Dissatisfaction in female college students.

    PubMed

    Spresser, Carrie D; Keune, Kristen M; Filion, Diane L; Lundgren, Jennifer D

    2012-03-01

    The purpose was to compare self-report and psychophysiological assessment techniques in the measurement of emotional response to body image cues. Female college students (n=53; % Caucasian=53.6; M body mass index=26.1 kg/m²) completed the Eating Disorder Inventory (EDI-3) and viewed photos of themselves both unaltered and morphed to simulate weight gain. Response to the photos was assessed by self-report and the affect modulated startle paradigm. EDI-3 Drive for Thinness (DT) and Body Dissatisfaction (BD) scale scores were correlated with startled amplitude for the largest simulated weight gain photo. Startle eye blink amplitude predicted more variance in DT and BD subscales than self-reported response to the image. The affect modulated startle paradigm may provide unique information in the assessment of eating disorder symptomatology that cannot be captured via self-report techniques, and has potential to inform evaluation of treatment outcomes of eating and body image disorders.

  10. Distance Probes of Dark Energy

    DOE PAGES

    Kim, A. G.; Padmanabhan, N.; Aldering, G.; ...

    2015-03-15

    We present the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). This document summarizes the current state of the field as well as future prospects and challenges. In addition to the established probes using Type Ia supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays.

  11. Linking Dimensional Models of Internalizing Psychopathology to Neurobiological Systems: Affect-Modulated Startle as an Indicator of Fear and Distress Disorders and Affiliated Traits

    PubMed Central

    Vaidyanathan, Uma; Patrick, Christopher J.; Cuthbert, Bruce N.

    2009-01-01

    Integrative hierarchical models have sought to account for the extensive comorbidity between various internalizing disorders in terms of broad individual difference factors these disorders share. However, such models have been developed largely on the basis of self-report and diagnostic symptom data. Toward the goal of linking such models to neurobiological systems, we review studies that have employed variants of the affect-modulated startle paradigm to investigate emotional processing in internalizing disorders as well as personality constructs known to be associated with these disorders. Specifically, we focus on four parameters of startle reactivity: fear-potentiated startle, inhibition of startle in the context of pleasant stimuli, context-potentiated startle, and general startle reactivity. On the basis of available data, we argue that these varying effects index differing neurobiological processes related to mood and anxiety disorders that are interpretable from the standpoint of dimensional models of the internalizing spectrum. Further, we contend that these empirical findings can feed back into and help reshape conceptualizations of internalizing disorders in ways that make them more amenable to neurobiological analysis. PMID:19883142

  12. Acoustic iridescence.

    PubMed

    Cox, Trevor J

    2011-03-01

    An investigation has been undertaken into acoustic iridescence, exploring how a device can be constructed which alter sound waves, in a similar way to structures in nature that act on light to produce optical iridescence. The main construction had many thin perforated sheets spaced half a wavelength apart for a specified design frequency. The sheets create the necessary impedance discontinuities to create backscattered waves, which then interfere to create strongly reflected sound at certain frequencies. Predictions and measurements show a set of harmonics, evenly spaced in frequency, for which sound is reflected strongly. And the frequency of these harmonics increases as the angle of observation gets larger, mimicking the iridescence seen in natural optical systems. Similar to optical systems, the reflections become weaker for oblique angles of reflection. A second construction was briefly examined which exploited a metamaterial made from elements and inclusions which were much smaller than the wavelength. Boundary element method predictions confirmed the potential for creating acoustic iridescence from layers of such a material.

  13. Acoustic transducer

    DOEpatents

    Drumheller, D.S.

    1997-12-30

    An acoustic transducer is described comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2,000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers. 4 figs.

  14. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    1997-01-01

    An acoustic transducer comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers.

  15. Glycine and GABAA receptors mediate tonic and phasic inhibitory processes that contribute to prepulse inhibition in the goldfish startle network

    PubMed Central

    Curtin, Paul C. P.; Preuss, Thomas

    2015-01-01

    Prepulse inhibition (PPI) is understood as a sensorimotor gating process that attenuates sensory flow to the startle pathway during early stages (20–1000 ms) of information processing. Here, we applied in vivo electrophysiology and pharmacology to determine if PPI is mediated by glycine receptors (GlyRs) and/or GABAA receptors (GABAARs) in the goldfish auditory startle circuit. Specifically, we used selective antagonists to dissect the contributions of target receptors on sound-evoked postsynaptic potentials (PSPs) recorded in the neurons that initiate startle, the Mauthner-cells (M-cell). We found that strychnine, a GlyR antagonist, disrupted a fast-activated (5 ms) and rapidly (<50 ms) decaying (feed-forward) inhibitory process that contributes to PPI at 20 ms prepulse/pulse inter-stimulus intervals (ISI). Additionally we observed increases of the evoked postsynaptic potential (PSP) peak amplitude (+87.43 ± 21.53%, N = 9) and duration (+204 ± 48.91%, N = 9). In contrast, treatment with bicuculline, a GABAAR antagonist, caused a general reduction in PPI across all tested interstimulus intervals (ISIs) (20–500 ms). Bicuculline also increased PSP peak amplitude (+133.8 ± 10.3%, N = 5) and PSP duration (+284.95 ± 65.64%, N = 5). Treatment with either antagonist also tonically increased post-synaptic excitability in the M-cells, reflected by an increase in the magnitude of antidromically-evoked action potentials (APs) by 15.07 ± 3.21%, N = 7 and 16.23 ± 7.08%, N = 5 for strychnine and bicuculline, respectively. These results suggest that GABAARs and GlyRs are functionally segregated to short- and longer-lasting sound-evoked (phasic) inhibitory processes that contribute to PPI, with the mediation of tonic inhibition by both receptor systems being critical for gain control within the M-cell startle circuit. PMID:25852486

  16. Oxytocin and Social Support as Synergistic Inhibitors of Aversive Fear Conditioning and Fear-Potentiated Startle in Male Rats

    DTIC Science & Technology

    2010-09-01

    disorder. Psychoneuroendocrinology 34: 917-923. Heinrichs M, Baumgartner T, Kirschbaum C, Ehlert U (2003). Social support and oxytocin interact to...TITLE: Oxytocin and Social Support as Synergistic Inhibitors of Aversive Fear Conditioning and Fear-Potentiated Startle in Male Rats PRINCIPAL...Annual 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Oxytocin and Social Support as Synergistic Inhibitors of 5a. CONTRACT NUMBER

  17. Planetary surface research with acoustic sounding

    NASA Astrophysics Data System (ADS)

    Krause, C.; Seidensticker, K. J.

    2007-08-01

    Planetary space missions like Rosetta and ExoMars put more and more emphasis on the in-situ investigation of planetary surfaces. The use of mechanical vibrations in the audible frequency range provide a new means to study the structure and properties of the surface layers of terrestrial planets and minor bodies like comets. As the first of this new type of instruments, the Comet Acoustic Surface Sounding Experiment (CASSE) on the Rosetta Lander Philae intends to determine elastic parameters and the structure of the surface layer of the target comet. One drawback of CASSE is unknown possibly weak coupling to the cometary surface. A DFG project is being conducted at the DLR - Deutsches Zentrum für Luft- und Raumfahrt - to test the applicability of planetary penetration instruments like PLUTO, planetary sampling tool, developed for the Mars Express lander Beagle 2, or MUPUS, a heat probe instrument also on Philae, as stronger acoustic sources as well as to develop new methods for the analysis of acoustic data. From the analysis of the polarisation of the recorded acoustic signals it is possible to separate the mixture of different propagating wave types. These identified waves can be used for the determination of mechanical soil properties and near-surface layering. We also will present how acoustic receivers can be used to locate acoustic penetrators or nearby seismic sources using the travel time and/or the polarisation of the acoustic waves.

  18. Startle response memory and hippocampal changes in adult zebrafish pharmacologically-induced to exhibit anxiety/depression-like behaviors.

    PubMed

    Pittman, Julian T; Lott, Chad S

    2014-01-17

    Zebrafish (Danio rerio) are rapidly becoming a popular animal model for neurobehavioral and psychopharmacological research. While startle testing is a well-established assay to investigate anxiety-like behaviors in different species, screening of the startle response and its habituation in zebrafish is a new direction of translational biomedical research. This study focuses on a novel behavioral protocol to assess a tapping-induced startle response and its habituation in adult zebrafish that have been pharmacologically-induced to exhibit anxiety/depression-like behaviors. We demonstrated that zebrafish exhibit robust learning performance in a task adapted from the mammalian literature, a modified plus maze, and showed that ethanol and fluoxetine impair memory performance in this maze when administered after training at a dose that does not impair motor function, however, leads to significant upregulation of hippocampal serotoninergic neurons. These results suggest that the maze associative learning paradigm has face and construct validity and that zebrafish may become a translationally relevant study species for the analysis of the mechanisms of learning and memory changes associated with psychopharmacological treatment of anxiety/depression.

  19. Contextual-specificity of short-delay extinction in humans: Renewal of fear-potentiated startle in a virtual environment

    PubMed Central

    Alvarez, Ruben P.; Johnson, Linda; Grillon, Christian

    2007-01-01

    A recent fear-potentiated startle study in rodents suggested that extinction was not context dependent when extinction was conducted after a short delay following acquisition, suggesting that extinction can lead to erasure of fear learning in some circumstances. The main objective of this study was to attempt to replicate these findings in humans by examining the context specificity of short-delay extinction in an ABA renewal procedure using virtual reality environments. A second objective was to examine whether renewal, if any, would be influenced by context conditioning. Subjects underwent differential aversive conditioning in virtual context A, which was immediately followed by extinction in virtual context B. Extinction was followed by tests of renewal in context A and B, with the order counterbalanced across subjects. Results showed that extinction was context dependent. Evidence for renewal was established using fear-potentiated startle as well as skin conductance and fear ratings. In addition, although contextual anxiety was greater in the acquisition context than in the extinction context during renewal, as assessed with startle, context conditioning did not influence the renewal effect. These data do not support the view that extinction conducted shortly after acquisition is context independent. Hence, they do not provide evidence that extinction can lead to erasure of a fear memory established via Pavlovian conditioning. PMID:17412963

  20. Acoustic cryocooler

    DOEpatents

    Swift, Gregory W.; Martin, Richard A.; Radenbaugh, Ray

    1990-01-01

    An acoustic cryocooler with no moving parts is formed from a thermoacoustic driver (TAD) driving a pulse tube refrigerator (PTR) through a standing wave tube. Thermoacoustic elements in the TAD are spaced apart a distance effective to accommodate the increased thermal penetration length arising from the relatively low TAD operating frequency in the range of 15-60 Hz. At these low operating frequencies, a long tube is required to support the standing wave. The tube may be coiled to reduce the overall length of the cryocooler. One or two PTR's are located on the standing wave tube adjacent antinodes in the standing wave to be driven by the standing wave pressure oscillations. It is predicted that a heat input of 1000 W at 1000 K will maintian a cooling load of 5 W at 80 K.

  1. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    2000-01-01

    An active acoustic transducer tool for use down-hole applications. The tool includes a single cylindrical mandrel including a shoulder defining the boundary of a narrowed portion over which is placed a sandwich-style piezoelectric tranducer assembly. The piezoelectric transducer assembly is prestressed by being placed in a thermal interference fit between the shoulder of the mandrel and the base of an anvil which is likewise positioned over the narrower portion of the mandrel. In the preferred embodiment, assembly of the tool is accomplished using a hydraulic jack to stretch the mandrel prior to emplacement of the cylindrical sandwich-style piezoelectric transducer assembly and anvil. After those elements are positioned and secured, the stretched mandrel is allowed to return substantially to its original (pre-stretch) dimensions with the result that the piezoelectric transducer elements are compressed between the anvil and the shoulder of the mandrel.

  2. Echo Ranging/Probe Alert Performance Analysis.

    DTIC Science & Technology

    1982-11-04

    contract included technical analyses of acoustic communication equipment, system performance predictions, sea test design and data analysis, and...proposing functional system design alternatives. 2.0 SUMMARY OF WORK PERFORMED The JAYCOR effort focused on the analysis of the Echo Ranging/ Probe Alert...JAYCOR Document No. J640-020-82-2242, 16 August 1982, CONFIDENTIAL. 13. Probe Alert Design System Performance Estimates (U), J.L. Collins, JAYCOR Document

  3. Acoustic telemetry.

    SciTech Connect

    Drumheller, Douglas Schaeffer; Kuszmaul, Scott S.

    2003-08-01

    Broadcasting messages through the earth is a daunting task. Indeed, broadcasting a normal telephone conversion through the earth by wireless means is impossible with todays technology. Most of us don't care, but some do. Industries that drill into the earth need wireless communication to broadcast navigation parameters. This allows them to steer their drill bits. They also need information about the natural formation that they are drilling. Measurements of parameters such as pressure, temperature, and gamma radiation levels can tell them if they have found a valuable resource such as a geothermal reservoir or a stratum bearing natural gas. Wireless communication methods are available to the drilling industry. Information is broadcast via either pressure waves in the drilling fluid or electromagnetic waves in the earth and well tubing. Data transmission can only travel one way at rates around a few baud. Given that normal Internet telephone modems operate near 20,000 baud, these data rates are truly very slow. Moreover, communication is often interrupted or permanently blocked by drilling conditions or natural formation properties. Here we describe a tool that communicates with stress waves traveling through the steel drill pipe and production tubing in the well. It's based on an old idea called Acoustic Telemetry. But what we present here is more than an idea. This tool exists, it's drilled several wells, and it works. Currently, it's the first and only acoustic telemetry tool that can withstand the drilling environment. It broadcasts one way over a limited range at much faster rates than existing methods, but we also know how build a system that can communicate both up and down wells of indefinite length.

  4. Depletion of serotonin in the basolateral amygdala elevates glutamate receptors and facilitates fear-potentiated startle

    PubMed Central

    Tran, L; Lasher, B K; Young, K A; Keele, N B

    2013-01-01

    Our previous experiments demonstrated that systemic depletion of serotonin (5-hydroxytryptamine, 5-HT), similar to levels reported in patients with emotional disorders, enhanced glutamateric activity in the lateral nucleus of the amygdala (LA) and potentiated fear behaviors. However, the effects of isolated depletion of 5-HT in the LA, and the molecular mechanisms underlying enhanced glutamatergic activity are unknown. In the present study, we tested the hypothesis that depletion of 5-HT in the LA induces increased fear behavior, and concomitantly enhances glutamate receptor (GluR) expression. Bilateral infusions of 5,7-dihydroxytryptamine (4 μg per side) into the LA produced a regional reduction of serotonergic fibers, resulting in decreased 5-HT concentrations. The induction of low 5-HT in the LA elevated fear-potentiated startle, with a parallel increase in GluR1 mRNA and GluR1 protein expression. These findings suggest that low 5-HT concentrations in the LA may facilitate fear behavior through enhanced GluR-mediated mechanisms. Moreover, our data support a relationship between 5-HT and glutamate in psychopathologies. PMID:24002084

  5. Prepulse inhibition of the startle reflex: a window on the brain in schizophrenia.

    PubMed

    Braff, David L

    2010-01-01

    Prepulse inhibition (PPI) of the startle response is an important measure of information processing deficits and inhibitory failure in schizophrenia patients. PPI is especially useful because it occurs in the same lawful manner in all mammals, from humans to rodents, making it an ideal candidate for cross-species translational research. PPI deficits occur across the "schizophrenia spectrum" from schizophrenia patients to their clinically unaffected relatives. Parallel animal model and human brain imaging studies have demonstrated that PPI is modulated by cortico-striato-pallido-thalamic (and pontine) circuitry. This circuitry is also implicated in schizophrenia neuropathology and neurophysiology. The finding of PPI deficits in schizophrenia patients has been replicated by many groups, and these deficits correlate with measures of thought disorder and appear to be "normalized" by second generation antipsychotic (SGA) medications. Consistent pharmacological effects on PPI have been demonstrated; among these, dopamine agonists induce PPI deficits and (in animal models) these are reversed by first and SGA medications. PPI is also significantly heritable in humans and animals and can be used as a powerful endophenotype in studies of families of schizophrenia patients. Genomic regions, including the NRGL-ERBB4 complex with its glutamatergic influences, are strongly implicated in PPI deficits in schizophrenia. PPI continues to hold promise as an exciting translational cross-species measure that can be used to understand the pathophysiology and treatment of the schizophrenias via pharmacological, anatomic, and genetic studies.

  6. The effects of flow on schooling Devario aequipinnatus: school structure, startle response and information transmission.

    PubMed

    Chicoli, A; Butail, S; Lun, Y; Bak-Coleman, J; Coombs, S; Paley, D A

    2014-05-01

    To assess how flow affects school structure and threat detection, startle response rates of solitary and small groups of giant danio Devario aequipinnatus to visual looming stimuli were compared in flow and no-flow conditions. The instantaneous position and heading of each D. aequipinnatus was extracted from high-speed videos. Behavioural results indicate that (1) school structure is altered in flow such that D. aequipinnatus orient upstream while spanning out in a crosswise direction, (2) the probability of at least one D. aequipinnatus detecting the visual looming stimulus is higher in flow than no flow for both solitary D. aequipinnatus and groups of eight D. aequipinnatus; however, (3) the probability of three or more individuals responding is higher in no flow than in flow. These results indicate a higher probability of stimulus detection in flow but a higher probability of internal transmission of information in no flow. Finally, results were well predicted by a computational model of collective fright response that included the probability of direct detection (based on signal detection theory) and indirect detection (i.e. via interactions between group members) of threatening stimuli. This model provides a new theoretical framework for analysing the collective transfer of information among groups of fishes and other organisms.

  7. The effects of flow on schooling Devario aequipinnatus: school structure, startle response and information transmission

    PubMed Central

    Chicoli, A.; Butail, S.; Lun, Y.; Bak-Coleman, J.; Coombs, S.; Paley, D.A.

    2014-01-01

    To assess how flow affects school structure and threat detection, startle response rates of solitary and small groups of giant danio Devario aequipinnatus were compared to visual looming stimuli in flow and no-flow conditions. The instantaneous position and heading of each D. aequipinnatus were extracted from high-speed videos. Behavioural results indicate that (1) school structure is altered in flow such that D. aequipinnatus orient upstream while spanning out in a crosswise direction, (2) the probability of at least one D. aequipinnatus detecting the visual looming stimulus is higher in flow than no flow for both solitary D. aequipinnatus and groups of eight D. aequipinnatus, however, (3) the probability of three or more individuals responding is higher in no flow than flow. Taken together, these results indicate a higher probability of stimulus detection in flow but a higher probability of internal transmission of information in no flow. Finally, results were well predicted by a computational model of collective fright response that included the probability of direct detection (based on signal detection theory) and indirect detection (i.e. via interactions between group members) of threatening stimuli. This model provides a new theoretical framework for analysing the collective transfer of information among groups of fishes and other organisms. PMID:24773538

  8. Optical probe

    DOEpatents

    Hencken, Kenneth; Flower, William L.

    1999-01-01

    A compact optical probe is disclosed particularly useful for analysis of emissions in industrial environments. The instant invention provides a geometry for optically-based measurements that allows all optical components (source, detector, rely optics, etc.) to be located in proximity to one another. The geometry of the probe disclosed herein provides a means for making optical measurements in environments where it is difficult and/or expensive to gain access to the vicinity of a flow stream to be measured. Significantly, the lens geometry of the optical probe allows the analysis location within a flow stream being monitored to be moved while maintaining optical alignment of all components even when the optical probe is focused on a plurality of different analysis points within the flow stream.

  9. Acoustic source for generating an acoustic beam

    DOEpatents

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

    2016-05-31

    An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

  10. Inhibition of auditory evoked potentials and prepulse inhibition of startle in DBA/2J and DBA/2Hsd inbred mouse substrains.

    PubMed

    Connolly, Patrick M; Maxwell, Christina R; Kanes, Stephen J; Abel, Ted; Liang, Yuling; Tokarczyk, Jan; Bilker, Warren B; Turetsky, Bruce I; Gur, Raquel E; Siegel, Steven J

    2003-11-28

    Previous data have shown differences among inbred mouse strains in sensory gating of auditory evoked potentials, prepulse inhibition (PPI) of startle, and startle amplitude. These measures of sensory and sensorimotor gating have both been proposed as models for genetic determinants of sensory processing abnormalities in patients with schizophrenia and their first-degree relatives. Data from our laboratory suggest that auditory evoked potentials of DBA/2J mice differ from those previously described for DBA/2Hsd. Therefore, we compared evoked potentials and PPI in these two closely related substrains based on the hypothesis that any observed endophenotypic differences are more likely to distinguish relevant from incidental genetic heterogeneity than similar approaches using inbred strains that vary across the entire genome. We found that DBA/2Hsd substrain exhibited reduced inhibition of evoked potentials and reduced startle relative to the DBA/2J substrain without alterations in auditory sensitivity, amplitude of evoked potentials or PPI of startle. These results suggest that gating of auditory evoked potentials and PPI of startle measure different aspects of neuronal function. The differences between the substrains might reflect genetic drift. Alternatively, differences could arise from different rearing environments or other non-genetic factors. Future studies will attempt to determine the cause of these differences in sensory and sensorimotor processing between these two closely related inbred mouse strains.

  11. Fear-potentiated startle to threat, and prepulse inhibition among young adult non-smokers, abstinent smokers, and non-abstinent smokers

    PubMed Central

    Grillon, Christian; Avenevoli, Shelli; Daurignac, Elsa; Merikangas, Kathleen R

    2007-01-01

    Background Evidence suggests that the transition from experimental to regular smoking is facilitated by the influence of tobacco on affective and attentional mechanisms. The objective of this study was to examine affective and attentional responses in young adult smokers using fear-potentiated startle and prepulse inhibition. Methods Participants were 56 college non smokers, non-abstinent smokers, and overnight-abstinent smokers. The fear-potentiated startle test examined phasic responses to imminent threat cues and more sustained responses to unpredictable aversive events. Prepulse inhibition investigated responses to attended and ignored prepulse stimuli. Results Abstinent and non-abstinent smokers showed increased sustained potentiation of startle to contextual cues, compared to controls. Abstinent smokers showed increased fear-potentiated startle to threat cues, compared to non-smokers. PPI did not discriminate between abstinent or non-abstinent smokers and controls. Conclusion These findings suggest that negative affectivity or anxiety is associated with smoking, particularly during withdrawal. Potentiated startle may provide a valuable tool in understanding the biologic mechanisms underlying nicotine withdrawal and inform cessation and prevention efforts. PMID:17543892

  12. The Impact of Early Neglect on Defensive and Appetitive Physiology during the Pubertal Transition; a Study of Startle and Postauricular Reflexes

    PubMed Central

    Johnson, Anna E.; Loman, Michelle M.; Lafavor, Theresa; Moua, Bao; Gunnar, Megan R.

    2016-01-01

    Objective This study tested the effect of early neglect on defensive and appetitive physiology during puberty. Method Emotion-modulated reflexes, eye-blink startle (defensive) and postauricular (appetitive), were measured in 12-to-13-year-old internationally adopted youth (from foster care or from institutional settings) and compared to non-adopted US born controls. Results Startle Reflex: adopted youth displayed lower overall startle amplitude across all valences and startle potentiation to negative images was negatively related to severity of pre-adoption neglect. Postauricular reflex (PAR): adopted youth showed larger PAR magnitude across all valences. Puberty: adopted youth showed diminished PAR potentiation to positive images and startle potentiation during mid/late puberty versus the opposite pattern in not-adopted. Conclusions Early neglect was associated with blunted fast defensive reflexes and heightened fast appetitive reflexes. After puberty, early neglected youth showed physiological hyporeactivity to threatening and appetitive stimuli versus heightened reactivity in not adopted youth. Behavioral correlates in this sample and possible neurodevelopmental mechanisms of psychophysiological differences are discussed. PMID:25773732

  13. Canonical Acoustics and Its Application to Surface Acoustic Wave on Acoustic Metamaterials

    NASA Astrophysics Data System (ADS)

    Shen, Jian Qi

    2016-08-01

    In a conventional formalism of acoustics, acoustic pressure p and velocity field u are used for characterizing acoustic waves propagating inside elastic/acoustic materials. We shall treat some fundamental problems relevant to acoustic wave propagation alternatively by using canonical acoustics (a more concise and compact formalism of acoustic dynamics), in which an acoustic scalar potential and an acoustic vector potential (Φ ,V), instead of the conventional acoustic field quantities such as acoustic pressure and velocity field (p,u) for characterizing acoustic waves, have been defined as the fundamental variables. The canonical formalism of the acoustic energy-momentum tensor is derived in terms of the acoustic potentials. Both the acoustic Hamiltonian density and the acoustic Lagrangian density have been defined, and based on this formulation, the acoustic wave quantization in a fluid is also developed. Such a formalism of acoustic potentials is employed to the problem of negative-mass-density assisted surface acoustic wave that is a highly localized surface bound state (an eigenstate of the acoustic wave equations). Since such a surface acoustic wave can be strongly confined to an interface between an acoustic metamaterial (e.g., fluid-solid composite structures with a negative dynamical mass density) and an ordinary material (with a positive mass density), it will give rise to an effect of acoustic field enhancement on the acoustic interface, and would have potential applications in acoustic device design for acoustic wave control.

  14. What Is an Acoustic Neuroma

    MedlinePlus

    ... ANAUSA.org Connect with us! What is an Acoustic Neuroma? Each heading slides to reveal information. Important ... Acoustic Neuroma Important Points To Know About an Acoustic Neuroma An acoustic neuroma, also called a vestibular ...

  15. Mutations in the GlyT2 Gene (SLC6A5) Are a Second Major Cause of Startle Disease*

    PubMed Central

    Carta, Eloisa; Chung, Seo-Kyung; James, Victoria M.; Robinson, Angela; Gill, Jennifer L.; Remy, Nathalie; Vanbellinghen, Jean-François; Drew, Cheney J. G.; Cagdas, Sophie; Cameron, Duncan; Cowan, Frances M.; Del Toro, Mireria; Graham, Gail E.; Manzur, Adnan Y.; Masri, Amira; Rivera, Serge; Scalais, Emmanuel; Shiang, Rita; Sinclair, Kate; Stuart, Catriona A.; Tijssen, Marina A. J.; Wise, Grahame; Zuberi, Sameer M.; Harvey, Kirsten; Pearce, Brian R.; Topf, Maya; Thomas, Rhys H.; Supplisson, Stéphane; Rees, Mark I.; Harvey, Robert J.

    2012-01-01

    Hereditary hyperekplexia or startle disease is characterized by an exaggerated startle response, evoked by tactile or auditory stimuli, leading to hypertonia and apnea episodes. Missense, nonsense, frameshift, splice site mutations, and large deletions in the human glycine receptor α1 subunit gene (GLRA1) are the major known cause of this disorder. However, mutations are also found in the genes encoding the glycine receptor β subunit (GLRB) and the presynaptic Na+/Cl−-dependent glycine transporter GlyT2 (SLC6A5). In this study, systematic DNA sequencing of SLC6A5 in 93 new unrelated human hyperekplexia patients revealed 20 sequence variants in 17 index cases presenting with homozygous or compound heterozygous recessive inheritance. Five apparently unrelated cases had the truncating mutation R439X. Genotype-phenotype analysis revealed a high rate of neonatal apneas and learning difficulties associated with SLC6A5 mutations. From the 20 SLC6A5 sequence variants, we investigated glycine uptake for 16 novel mutations, confirming that all were defective in glycine transport. Although the most common mechanism of disrupting GlyT2 function is protein truncation, new pathogenic mechanisms included splice site mutations and missense mutations affecting residues implicated in Cl− binding, conformational changes mediated by extracellular loop 4, and cation-π interactions. Detailed electrophysiology of mutation A275T revealed that this substitution results in a voltage-sensitive decrease in glycine transport caused by lower Na+ affinity. This study firmly establishes the combination of missense, nonsense, frameshift, and splice site mutations in the GlyT2 gene as the second major cause of startle disease. PMID:22700964

  16. Symptoms of Acoustic Neuroma

    MedlinePlus

    ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  17. NPL closes acoustics department

    NASA Astrophysics Data System (ADS)

    Extance, Andy

    2016-11-01

    The UK's National Physical Laboratory (NPL) has withdrawn funding for its acoustics, polymer and thermoelectrics groups, triggering concern among airborne acoustics specialists that the move could undermine the country's noise-management policies.

  18. Identifying the Acoustic Neuroma

    MedlinePlus

    ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  19. Cannabidiol, among Other Cannabinoid Drugs, Modulates Prepulse Inhibition of Startle in the SHR Animal Model: Implications for Schizophrenia Pharmacotherapy

    PubMed Central

    Peres, Fernanda F.; Levin, Raquel; Almeida, Valéria; Zuardi, Antonio W.; Hallak, Jaime E.; Crippa, José A.; Abilio, Vanessa C.

    2016-01-01

    Schizophrenia is a severe psychiatric disorder that involves positive, negative and cognitive symptoms. Prepulse inhibition of startle reflex (PPI) is a paradigm that assesses the sensorimotor gating functioning and is impaired in schizophrenia patients as well as in animal models of this disorder. Recent data point to the participation of the endocannabinoid system in the pathophysiology and pharmacotherapy of schizophrenia. Here, we focus on the effects of cannabinoid drugs on the PPI deficit of animal models of schizophrenia, with greater focus on the SHR (Spontaneously Hypertensive Rats) strain, and on the future prospects resulting from these findings. PMID:27667973

  20. Acoustic emission frequency discrimination

    NASA Technical Reports Server (NTRS)

    Sugg, Frank E. (Inventor); Graham, Lloyd J. (Inventor)

    1988-01-01

    In acoustic emission nondestructive testing, broadband frequency noise is distinguished from narrow banded acoustic emission signals, since the latter are valid events indicative of structural flaws in the material being examined. This is accomplished by separating out those signals which contain frequency components both within and beyond (either above or below) the range of valid acoustic emission events. Application to acoustic emission monitoring during nondestructive bond verification and proof loading of undensified tiles on the Space Shuttle Orbiter is considered.

  1. Deep Water Ocean Acoustics

    DTIC Science & Technology

    2015-07-17

    under-ice scattering , bathymetric diffraction and the application of the ocean acoustic Parabolic Equation to infrasound. 2. Tasks a. Task 1...QSR-14C0172-Ocean Acoustics -063015 Figure 10. Estimated reflection coefficient as a function of frequency by taking the difference of downgoing and...OASIS, INC. 1 Report No. QSR-14C0172-Ocean Acoustics -063015 Quarterly Progress Report Technical and Financial Deep Water Ocean Acoustics

  2. Deep Water Ocean Acoustics

    DTIC Science & Technology

    2015-10-19

    OASIS, INC. 1 Report No. QSR-14C0172-Ocean Acoustics-093015 Quarterly Progress Report Technical and Financial Deep Water Ocean Acoustics...number. 1. REPORT DATE OCT 2015 2. REPORT TYPE 3. DATES COVERED 01-07-2015 to 30-09-2015 4. TITLE AND SUBTITLE Deep Water Ocean Acoustics...understanding of the impact of the ocean and seafloor environmental variability on deep- water (long-range) ocean acoustic propagation and to develop

  3. Shallow Water Acoustics Studies

    DTIC Science & Technology

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Shallow Water Acoustics Studies James F. Lynch MS #12...N00014-14-1-0040 http://acoustics.whoi.edu/sw06/ LONG TERM GOALS The long term goals of our shallow water acoustics work are to: 1) understand the...nature of low frequency (10-1500 Hz) acoustic propagation, scattering and noise in shallow water when strong oceanic variability is present in the

  4. Effect of Seated Trunk Posture on Eye Blink Startle and Subjective Experience: Comparing Flexion, Neutral Upright Posture, and Extension of Spine

    PubMed Central

    Ceunen, Erik; Zaman, Jonas; Vlaeyen, Johan W. S.; Dankaerts, Wim; Van Diest, Ilse

    2014-01-01

    Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective) modulation of eye blink startle occurs following specific postures. The objective of the current study was to explore this. Participants in the present study were requested to assume three different sitting postures: with the spine flexed (slouched), neutral upright, and extended. Each posture was assumed for four minutes, and was followed by the administration of brief self-report questionnaires before proceeding to the next posture. The same series of postures and measures were repeated prior to ending the experiment. Results indicate that, relative to the other postures, the extended sitting posture was associated with an increased startle, was more unpleasant, arousing, had smaller levels of dominance, induced more discomfort, and was perceived as more difficult. The upright and flexed sitting postures differed in the level of self-reported positive affect, but not in eye blink startle amplitudes. PMID:24516664

  5. Coding Acoustic Metasurfaces.

    PubMed

    Xie, Boyang; Tang, Kun; Cheng, Hua; Liu, Zhengyou; Chen, Shuqi; Tian, Jianguo

    2017-02-01

    Coding acoustic metasurfaces can combine simple logical bits to acquire sophisticated functions in wave control. The acoustic logical bits can achieve a phase difference of exactly π and a perfect match of the amplitudes for the transmitted waves. By programming the coding sequences, acoustic metasurfaces with various functions, including creating peculiar antenna patterns and waves focusing, have been demonstrated.

  6. Tutorial on architectural acoustics

    NASA Astrophysics Data System (ADS)

    Shaw, Neil; Talaske, Rick; Bistafa, Sylvio

    2002-11-01

    This tutorial is intended to provide an overview of current knowledge and practice in architectural acoustics. Topics covered will include basic concepts and history, acoustics of small rooms (small rooms for speech such as classrooms and meeting rooms, music studios, small critical listening spaces such as home theatres) and the acoustics of large rooms (larger assembly halls, auditoria, and performance halls).

  7. Physical acoustics of ultrasound-assisted lipoplasty.

    PubMed

    Weninger, K; Camara, C; Putterman, S

    1999-07-01

    The acoustic fields generated by probes and cannulas used for ultrasound-assisted lipoplasty (UAL) are sources of cavitation and sonoluminescence. The localized stress fields and heating caused by cavitation are strong enough to lyse cells and, in the authors' opinion, constitute the means of therapeutic action of UAL. The spectrum of sonoluminescence extends into the ultraviolet. Various devices have been calibrated and various issues relating to health risks are discussed.

  8. Acoustically induced stark effect for excitons in intrinsic semiconductors.

    PubMed

    Ivanov, A L; Littlewood, P B

    2001-09-24

    A Stark effect for excitons parametrically driven by coherent acoustic phonons is proposed. Our scheme refers to a low-temperature intrinsic semiconductor or semiconductor nanostructure pumped by an acoustic wave (frequency band nu(ac) approximately equal to 1-40 GHz and intensity range I(ac) approximately equal to 10(-2)-10(2) W/cm(2)) and probed by low-intensity light. Tunable optical band gaps, which strongly change the spectral shape of the exciton line, are induced in the polariton spectrum by acoustic pumping. We develop an exactly solvable model of the acoustic Stark effect and apply our results to GaAs driven by bulk or surface acoustic waves.

  9. Indoor acoustic gain design

    NASA Astrophysics Data System (ADS)

    Concha-Abarca, Justo Andres

    2002-11-01

    The design of sound reinforcement systems includes many variables and usually some of these variables are discussed. There are criteria to optimize the performance of the sound reinforcement systems under indoor conditions. The equivalent acoustic distance, the necessary acoustic gain, and the potential acoustic gain are parameters which must be adjusted with respect to the loudspeaker array, electric power and directionality of loudspeakers, the room acoustics conditions, the distance and distribution of the audience, and the type of the original sources. The design and installation of front of the house and monitoring systems have individual criteria. This article is about this criteria and it proposes general considerations for the indoor acoustic gain design.

  10. Pollution Probe.

    ERIC Educational Resources Information Center

    Chant, Donald A.

    This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

  11. [INVITED] Laser generation and detection of ultrafast shear acoustic waves in solids and liquids

    NASA Astrophysics Data System (ADS)

    Pezeril, Thomas

    2016-09-01

    The aim of this article is to provide an overview of the up-to-date findings related to ultrafast shear acoustic waves. Recent progress obtained for the laser generation and detection of picosecond shear acoustic waves in solids and liquids is reviewed. Examples in which the transverse isotropic symmetry of the sample structure is broken in order to permit shear acoustic wave generation through sudden laser heating are described in detail. Alternative photo-induced mechanisms for ultrafast shear acoustic generation in metals, semiconductors, insulators, magnetostrictive, piezoelectric and electrostrictive materials are reviewed as well. With reference to key experiments, an all-optical technique employed to probe longitudinal and shear structural dynamics in the GHz frequency range in ultra-thin liquid films is described. This technique, based on specific ultrafast shear acoustic transducers, has opened new perspectives that will be discussed for ultrafast shear acoustic probing of viscoelastic liquids at the nanometer scale.

  12. Unidirectional startle responses and disrupted left-right coordination of motor behaviors in robo3 mutant zebrafish

    PubMed Central

    Burgess, Harold A.; Johnson, Stephen L.; Granato, Michael

    2009-01-01

    The Roundabout (Robo) family of receptors and their Slit ligands play well-established roles in axonal guidance, including in humans where horizontal gaze palsy with progressive scoliosis (HGPPS) is caused by mutations in the robo3 gene. While significant progress has been made towards understanding the mechanism by which Robo receptors establish commissural projections in the central nervous system, less is known about how these projections contribute to neural circuits mediating behavior. Here we report cloning of the zebrafish behavioral mutant twitch twice and show that twitch twice encodes robo3. We demonstrate that in mutant hindbrains the axons of an identified pair of neurons, the Mauthner cells, fail to cross the midline. The Mauthner neurons are essential for the startle response, and in twitch twice/robo3 mutants misguidance of the Mauthner axons results in a unidirectional startle response. Moreover, we show that twitch twice mutants exhibit normal visual acuity but display defects in horizontal eye movements, suggesting a specific and critical role for twitch twice/robo3 in sensory guided behavior. PMID:19496826

  13. AX+, BX- Discrimination Learning in the Fear-Potentiated Startle Paradigm: Possible Relevance to Inhibitory Fear Learning in Extinction

    PubMed Central

    Myers, Karyn M.; Davis, Michael

    2004-01-01

    The neural mechanisms of fear suppression most commonly are studied through the use of extinction, a behavioral procedure in which a feared stimulus (i.e., one previously paired with shock) is nonreinforced repeatedly, leading to a reduction or elimination of the fear response. Although extinction is perhaps the most convenient index of fear inhibition, a great deal of behavioral work suggests that postextinction training conditioned stimuli are both excitatory and inhibitory, making it difficult to determine whether a neural manipulation affects inhibition, excitation, or some combination thereof. For this reason we sought to develop a behavioral procedure that would render a stimulus primarily inhibitory while at the same time avoiding some of the issues raised by the traditional conditioned inhibition paradigm, namely second-order conditioning, external inhibition, and configural learning. Using the fear-potentiated startle paradigm, we adapted an AX+, BX- training procedure in which stimuli A and X were presented simultaneously and paired with shock, and stimuli B and X were presented simultaneously in the absence of shock. In testing, high levels of fear-potentiated startle were seen in the presence of A and AX and much lower levels were seen in the presence of B and AB, as would be predicted if stimulus B were a conditioned inhibitor. We believe this method is a viable alternative to the traditional conditioned inhibition training procedure and will be useful for studying the neural mechanisms of fear inhibition. PMID:15254216

  14. Prospective Associations between Emotion Dysregulation and Fear-Potentiated Startle: The Moderating Effect of Respiratory Sinus Arrhythmia

    PubMed Central

    Seligowski, Antonia V.; Lee, Daniel J.; Miron, Lynsey R.; Orcutt, Holly K.; Jovanovic, Tanja; Norrholm, Seth D.

    2016-01-01

    Background: Emotion dysregulation has been implicated in the negative outcomes following trauma exposure. A proposed biomarker of emotion dysregulation, respiratory sinus arrhythmia (RSA), has demonstrated associations with trauma-related phenomena, such as the fear-potentiated startle (FPS) response. The current study aimed to examine the prospective association between emotion dysregulation and RSA and FPS several years following trauma exposure. Methods: Participants were 131 women exposed to a campus mass shooting on February 14, 2008. Pre-shooting emotion dysregulation was assessed in 2006–2008. Startle response, measured by orbicularis oculi electromyography (EMG), and RSA were gathered during an FPS paradigm conducted from 2012 to 2015. Results: No significant associations among emotion dysregulation, RSA, and FPS emerged among the full sample. However, emotion dysregulation predicted FPS during both acquisition (r = 0.40, p < 0.05) and extinction (r = 0.57, p < 0.01) among individuals with high resting RSA. Conclusions: Findings suggest that pre-shooting emotion dysregulation is a potent predictor of FPS several years following potential trauma exposure, and this association varies by RSA level. Results emphasize the importance of examining autonomic regulation in the association between emotion dysregulation and recovery from trauma exposure. PMID:27199871

  15. The acoustic bubble: Ocean, cetacean and extraterrestrial acoustics, and cold water cleaning

    NASA Astrophysics Data System (ADS)

    Leighton, T. G.

    2017-01-01

    This paper summarizes the content of a plenary lecture on the author’s personal research into the interactions between bubbles and sound fields, covering particular topics involving the climatically important gas exchange between atmosphere and ocean, the implications of bubbly ocean water to marine mammals that use sound, and the opportunities afforded by incorporating acoustical sensors onto probes launched to investigate other worlds in our solar system. It closes with recent data on the opportunities of bubble acoustics to investigate methods of cold water cleaning.

  16. Rapid recovery following short-term acoustic disturbance in two fish species

    PubMed Central

    Bruintjes, Rick; Purser, Julia; Everley, Kirsty A.; Mangan, Stephanie; Simpson, Stephen D.; Radford, Andrew N.

    2016-01-01

    Noise from human activities is known to impact organisms in a variety of taxa, but most experimental studies on the behavioural effects of noise have focused on examining responses associated with the period of actual exposure. Unlike most pollutants, acoustic noise is generally short-lived, usually dissipating quickly after the source is turned off or leaves the area. In a series of experiments, we use established experimental paradigms to examine how fish behaviour and physiology are affected, both during short-term (2 min) exposure to playback of recordings of anthropogenic noise sources and in the immediate aftermath of noise exposure. We considered the anti-predator response and ventilation rate of juvenile European eels (Anguilla anguilla) and ventilation rate of juvenile European seabass (Dicentrarchus labrax). As previously found, additional-noise exposure decreased eel anti-predator responses, increased startle latency and increased ventilation rate relative to ambient-noise-exposed controls. Our results show for the first time that those effects quickly dissipated; eels showed rapid recovery of startle responses and startle latency, and rapid albeit incomplete recovery of ventilation rate in the 2 min after noise cessation. Seabass in both laboratory and open-water conditions showed an increased ventilation rate during playback of additional noise compared with ambient conditions. However, within 2 min of noise cessation, ventilation rate showed complete recovery to levels equivalent to ambient-exposed control individuals. Care should be taken in generalizing these rapid-recovery results, as individuals might have accrued other costs during noise exposure and other species might show different recovery times. Nonetheless, our results from two different fish species provide tentative cause for optimism with respect to recovery following short-duration noise exposure, and suggest that considering periods following noise exposures could be important

  17. Project PROBE Leg I - Report and archive of multibeam bathymetry and acoustic backscatter , CTD/XBT and GPS navigation data collected during USGS Cruise 02051 (NOAA Cruise RB0208) Puerto Rico Trench September 24, 2002 to September 30, 2002

    USGS Publications Warehouse

    ten Brink, Uri S.; Worley, Charles R.; Smith, Shep; Stepka, Thomas; Williams, Glynn F.

    2006-01-01

    On September 24-30, 2002, six days of scientific surveying to map a section of the Puerto Rico Trench (PRT) took place aboard the National Oceanic and Atmospheric Administration (NOAA) ship Ron Brown. The cruise was funded by NOAA's Office of Ocean Exploration. Multibeam bathymetry and acoustic-backscatter data were collected over an area of about 25,000 sq. km of the Puerto Rico trench and its vicinity at water depths of 4000-8400 m. Weather conditions during the entire survey were good; there were light to moderate winds and 1-2 foot swells experiencing minor chop. The roll and pitch of the ship's interaction with the ocean were not conspicuous. Cruise participants included personnel from USGS, NOAA, and University of New Hampshire Center for Coastal and Ocean Mapping/Joint Hydrographic Center. The cruise resulted in the discovery of a major active strike-slip fault system close to the trench, submarine slides on the descending North American tectonic plate, and an extinct mud volcano, which was cut by the strike-slip fault system. Another strike-slip fault system closer to Puerto Rico that was previously considered to accommodate much of the relative plate motion appears to be inactive. The seaward continuation of the Mona Rift, a zone of extension between Puerto Rico and the Dominican Republic that generated a devastating tsunami in 1918, was mapped for the first time.

  18. Reflectance measurement validation using acoustic horns

    PubMed Central

    Rasetshwane, Daniel M.; Neely, Stephen T.

    2015-01-01

    Variability in wideband acoustic reflectance (and absorbance) measurements adversely affects the clinical utility of reflectance for diagnosis of middle-ear disorders. A reflectance standard would encourage consistency across different measurement systems and help identify calibration related issues. Theoretical equations exist for the reflectance of finite-length exponential, conical, and parabolic acoustic horns. Reflectance measurements were repeatedly made in each of these three horn shapes and the results were compared to the corresponding theoretical reflectance. A method is described of adjusting acoustic impedance measurements to compensate for spreading of the wave front that propagates from the small diameter sound port of the probe to the larger diameter of the acoustic cavity. Agreement between measured and theoretical reflectance was less than 1 dB at most frequencies in the range from 0.2 to 10 kHz. Pearson correlation coefficients were greater than 0.95 between measured and theoretical time-domain reflectance within the flare region of the horns. The agreement suggests that the distributed reflectance of acoustic horns may be useful for validating reflectance measurements made in human ear canals; however, refinements to reflectance measurement methods may still be needed. PMID:26520306

  19. Reflectance measurement validation using acoustic horns.

    PubMed

    Rasetshwane, Daniel M; Neely, Stephen T

    2015-10-01

    Variability in wideband acoustic reflectance (and absorbance) measurements adversely affects the clinical utility of reflectance for diagnosis of middle-ear disorders. A reflectance standard would encourage consistency across different measurement systems and help identify calibration related issues. Theoretical equations exist for the reflectance of finite-length exponential, conical, and parabolic acoustic horns. Reflectance measurements were repeatedly made in each of these three horn shapes and the results were compared to the corresponding theoretical reflectance. A method is described of adjusting acoustic impedance measurements to compensate for spreading of the wave front that propagates from the small diameter sound port of the probe to the larger diameter of the acoustic cavity. Agreement between measured and theoretical reflectance was less than 1 dB at most frequencies in the range from 0.2 to 10 kHz. Pearson correlation coefficients were greater than 0.95 between measured and theoretical time-domain reflectance within the flare region of the horns. The agreement suggests that the distributed reflectance of acoustic horns may be useful for validating reflectance measurements made in human ear canals; however, refinements to reflectance measurement methods may still be needed.

  20. Dynamical Response of Continuum Regime Langmuir Probe

    NASA Astrophysics Data System (ADS)

    Rappaport, H. L.

    2009-11-01

    Probe dynamic response is sometimes used as a way to increase the amount of information obtained from Langmuir probes [1]. In this poster, the effects of frequency dependent probe capacitance and coupling of probe fields to damped Langmuir waves and damped ion acoustic waves are considered. In the continuum regime, with small Debye length to spherical probe radius ratio, the probe DC current vs. voltage characteristic displays a hard saturation at sufficiently large probe potential [2]. In this regime, the sheath thickness varies little with the applied voltage although the plasma response can still be measured. A goal of the present investigation is to show that the probe dynamical response is richer as a result of modulation of sheath thickness or shielding particularly in the larger Debye length to probe radius ratio regime. Inertia inhibits ion response at sufficiently high frequency and deviation from the DC characteristic is shown.[4pt] [1] D. N. Walker, R.F. Fernsler, D.D. Blackwell, and W.E. Amatucci, Phys. Plasmas 15, 123506 (2008).[0pt] [2] E. Baum and R.L. Chapkis, AIAA J. 8, 1073 (1970).

  1. Local oscillator phase noise limitation on the resolution of acoustic delay line wireless passive sensor measurement

    NASA Astrophysics Data System (ADS)

    Chrétien, N.; Friedt, J.-M.; Martin, G.

    2014-06-01

    The role of the phase noise of a local oscillator driving a pulsed-mode RADAR used for probing surface acoustic wave sensors is investigated. The echo delay, representative of the acoustic velocity, and hence the physical quantity probed by the sensor, is finely measured as a phase. Considering that the intrinsic oscillator phase fluctuation defines the phase noise measurement resolution, we experimentally and theoretically assess the relation between phase noise, measurement range, and measurand resolution.

  2. AST Launch Vehicle Acoustics

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.

  3. Mechanical perturbations applied during impending movement evoke startle-like responses

    PubMed Central

    Ravichandran, Vengateswaran J.; Shemmell, Jonathan B.; Perreault, Eric J.

    2010-01-01

    Stretch reflexes have been considered one of the simplest circuits in the human nervous system. Yet, their role is controversial given that they assist or resist an imposed perturbation depending on the task instruction. Evidence shows that a loud acoustic stimulus applied prior to an impending movement elicits a movement-direction dependent muscle activity. In our study, we found that a perturbation can also trigger this early onset of movement, if applied during movement preparation. These responses were also perturbation direction dependent. This suggests an interaction of between the limb-stabilizing stretch reflexes and the voluntary activity. PMID:19963543

  4. Acoustic Translation of an Acoustically Levitated Sample

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Allen, J. L.

    1986-01-01

    Acoustic-levitation apparatus uses only one acoustic mode to move sample from one region of chamber to another. Sample heated and cooled quickly by translation between hot and cold regions of levitation chamber. Levitated sample is raised into furnace region by raising plunger. Frequency of sound produced by transducers adjusted by feedback system to maintain (102) resonant mode, which levitates sample midway between transducers and plunger regardless of plunger position.

  5. Optimization of a contextual conditioning protocol for rats using combined measurements of startle amplitude and freezing: the effects of shock intensity and different types of conditioning.

    PubMed

    Luyten, Laura; Vansteenwegen, Debora; van Kuyck, Kris; Deckers, Dries; Nuttin, Bart

    2011-01-15

    Contextual conditioning in rats is typically quantified using startle amplitude or freezing time. Our goal was to create a robust contextual conditioning protocol combining both startle amplitude and freezing time as measures of contextual anxiety. Comparison of 0.8 mA - 250 ms shocks with an established shock configuration (0.3 mA - 1 s) favoured the first parameters. Subsequently, we systematically investigated the effect of shock intensity (0.6 mA, 0.8 mA or 1.0 mA) and concurrently compared two different contextual conditioning procedures (shocks alone versus unpaired shock-tone presentations). In future experiments, this second type of contextual conditioning may form the optimal contrasting condition for a cued fear conditioning group, trained with explicit cue-shock pairings. The 0.8 mA shocks produced significant contextual freezing and startle potentiation, whereas the 0.6 mA and 1.0 mA shocks only led to a significant increase of freezing time. We found no major differences between the two types of conditioning, implying that these procedures might be equivalent. In conclusion, training with ten 0.8 mA - 250 ms shocks produced reliable contextual conditioning as measured with both startle amplitude and freezing time.

  6. White matter microstructure of the uncinate fasciculus is associated with subthreshold posttraumatic stress disorder symptoms and fear potentiated startle during early extinction in recently deployed Service Members.

    PubMed

    Costanzo, Michelle E; Jovanovic, Tanja; Pham, Dzung; Leaman, Suzanne; Highland, Krista B; Norrholm, Seth Davin; Roy, Michael J

    2016-04-08

    Early intervention following combat deployment has the potential to prevent posttraumatic stress disorder (PTSD), but there is a need for greater understanding of the factors that contribute to PTSD symptom progression. This study investigated: (1) fear-potentiated startle during a fear extinction, (2) white matter microstructure, and (3) PTSD symptom severity, in 48 recently deployed service members (SMs) who did not have sufficient PTSD symptoms to meet criteria for a clinical diagnosis. Electromyography startle during a conditional discrimination paradigm, diffusion tensor imaging, and the Clinician Administered PTSD Scale were assessed in a cohort of SMs within 2 months after their return from Iraq or Afghanistan. Significant correlations were found between left uncinate fasciculus (UF) white matter tract integrity and total PTSD symptoms, r=-0.343, p=0.018; the left UF and hyperarousal symptoms, r=-0.29, p=0.047; right UF integrity and total PTSD symptoms r=-0.3371, p=0.01; right UF integrity and hyperarousal symptoms r=-0.332, p=0.023; left UF and startle during early extinction, r=.31, p=0.033. Our results indicate that compromise of UF tract frontal-limbic connections are associated with greater PTSD symptom severity and lower startle response during extinction. In a subthreshold population, such a relationship between brain structure, physiological reactivity, and behavioral expression may reveal vulnerabilities that could have significant implications for PTSD symptom development.

  7. Error-related brain activity is related to aversive potentiation of the startle response in children, but only the ERN is associated with anxiety disorders.

    PubMed

    Meyer, Alexandria; Hajcak, Greg; Glenn, Catherine R; Kujawa, Autumn J; Klein, Daniel N

    2017-04-01

    Identifying biomarkers that characterize developmental trajectories leading to anxiety disorders will likely improve early intervention strategies as well as increase our understanding of the etiopathogenesis of these disorders. The error-related negativity (ERN), an event-related potential that occurs during error commission, is increased in anxious adults and children-and has been shown to predict the onset of anxiety disorders across childhood. The ERN has therefore been suggested as a biomarker of anxiety. However, it remains unclear what specific processes a potentiated ERN may reflect. We have recently proposed that the ERN may reflect trait-like differences in threat sensitivity; however, very few studies have examined the ERN in relation to other indices of this construct. In the current study, the authors measured the ERN, as well as affective modulation of the startle reflex, in a large sample (N = 155) of children. Children characterized by a large ERN also exhibited greater potentiation of the startle response in the context of unpleasant images, but not in the context of neutral or pleasant images. In addition, the ERN, but not startle response, related to child anxiety disorder status. These results suggest a relationship between error-related brain activity and aversive potentiation of the startle reflex during picture viewing-consistent with the notion that both measures may reflect individual differences in threat sensitivity. However, results suggest the ERN may be a superior biomarker of anxiety in children. (PsycINFO Database Record

  8. Are cervical multifidus muscles active during whiplash and startle? An initial experimental study

    PubMed Central

    Siegmund, Gunter P; Blouin, Jean-Sébastien; Carpenter, Mark G; Brault, John R; Inglis, J Timothy

    2008-01-01

    Background The cervical multifidus muscles insert onto the lower cervical facet capsular ligaments and the cervical facet joints are the source of pain in some chronic whiplash patients. Reflex activation of the multifidus muscle during a whiplash exposure could potentially contribute to injuring the facet capsular ligament. Our goal was to determine the onset latency and activation amplitude of the cervical multifidus muscles to a simulated rear-end collision and a loud acoustic stimuli. Methods Wire electromyographic (EMG) electrodes were inserted unilaterally into the cervical multifidus muscles of 9 subjects (6M, 3F) at the C4 and C6 levels. Seated subjects were then exposed to a forward acceleration (peak acceleration 1.55 g, speed change 1.8 km/h) and a loud acoustic tone (124 dB, 40 ms, 1 kHz). Results Aside from one female, all subjects exhibited multifidus activity after both stimuli (8 subjects at C4, 6 subjects at C6). Neither onset latencies nor EMG amplitude varied with stimulus type or spine level (p > 0.13). Onset latencies and amplitudes varied widely, with EMG activity appearing within 160 ms of stimulus onset (for at least one of the two stimuli) in 7 subjects. Conclusion These data indicate that the multifidus muscles of some individuals are active early enough to potentially increase the collision-induced loading of the facet capsular ligaments. PMID:18534030

  9. Acoustical experiment of yogurt fermentation process.

    PubMed

    Ogasawara, H; Mizutani, K; Ohbuchi, T; Nakamura, T

    2006-12-22

    One of the important factors through food manufacturing is hygienic management. Thus, food manufactures prove their hygienic activities by taking certifications like a Hazard Analysis and Critical Control Point (HACCP). This concept also applies to food monitoring. Acoustical measurements have advantage for other measurement in food monitoring because they make it possible to measure with noncontact and nondestructive. We tried to monitor lactic fermentation of yogurt by a probing sensor using a pair of acoustic transducers. Temperature of the solution changes by the reaction heat of fermentation. Consequently the sound velocity propagated through the solution also changes depending on the temperature. At the same time, the solution change its phase from liquid to gel. The transducers usage in the solution indicates the change of the temperature as the change of the phase difference between two transducers. The acoustic method has advantages of nondestructive measurement that reduces contamination of food product by measuring instrument. The sensor was inserted into milk with lactic acid bacterial stain of 19 degrees C and monitored phase retardation of propagated acoustic wave and its temperature with thermocouples in the mild. The monitoring result of fermentation from milk to Caspian Sea yogurt by the acoustic transducers with the frequency of 3.7 MHz started to show gradient change in temperature caused by reaction heat of fermentation but stop the gradient change at the end although the temperature still change. The gradient change stopped its change because of phase change from liquid to gel. The present method will be able to measure indirectly by setting transducers outside of the measuring object. This noncontact sensing method will have great advantage of reduces risk of food contamination from measuring instrument because the measurement probes are set out of fermentation reactor or food containers. Our proposed method will contribute to the

  10. Nearfield Acoustical Holography

    NASA Astrophysics Data System (ADS)

    Hayek, Sabih I.

    Nearfield acoustical holography (NAH) is a method by which a set of acoustic pressure measurements at points located on a specific surface (called a hologram) can be used to image sources on vibrating surfaces on the acoustic field in three-dimensional space. NAH data are processed to take advantage of the evanescent wavefield to image sources that are separated less that one-eighth of a wavelength.

  11. Deep Water Acoustics

    DTIC Science & Technology

    2016-06-28

    Estimates of basin-wide sound speed ( temperature ) fields obtained by the combination of acoustic, altimetry, and other data types with ocean...of acoustic coherence at long ranges in the ocean. Estimates of basin-wide sound speed ( temperature ) fields obtained by the combination of acoustic...index.html Award Number N00014-13-1-0053 LONG-TERM GOALS The ultimate limitations to the performance of long-range sonar are due to ocean sound speed

  12. Acoustic Communications (ACOMMS) ATD

    DTIC Science & Technology

    2016-06-14

    Acoustic Communications (ACOMMS) ATD Tam Nguyen 2531 Jefferson Davis Hwy Arlington, VA 22242 phone: (703) 604-6013 ext 520 fax: (703) 604-6056...email: NguyenTL@navsea.navy.mil Award # N0001499PD30007 LONG-TERM GOALS The goal of the recently completed Acoustic Communications Advanced...Technology Demonstration program (ACOMMS ATD) was to demonstrate long range and moderate data rate underwater acoustic communications between a submarine

  13. Deep Water Ocean Acoustics

    DTIC Science & Technology

    2016-04-30

    OASIS, INC. 1 Report No. QSR-14C0172-Ocean Acoustics-043016 Quarterly Progress Report Technical and Financial Deep Water Ocean Acoustics...understanding of the impact of the ocean and seafloor environmental variability on deep- water (long-range) ocean acoustic propagation and to...improve our understanding. During the past few years, the physics effects studied have been three-dimensional propagation on global scales, deep water

  14. Acoustic dispersive prism

    NASA Astrophysics Data System (ADS)

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz–1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.

  15. Acoustic dispersive prism.

    PubMed

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R

    2016-01-07

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz-1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.

  16. Low frequency acoustic microscope

    DOEpatents

    Khuri-Yakub, Butrus T.

    1986-11-04

    A scanning acoustic microscope is disclosed for the detection and location of near surface flaws, inclusions or voids in a solid sample material. A focused beam of acoustic energy is directed at the sample with its focal plane at the subsurface flaw, inclusion or void location. The sample is scanned with the beam. Detected acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane are used for generating an interference signal which is processed and forms a signal indicative of the subsurface flaws, inclusions or voids.

  17. Acoustic dispersive prism

    PubMed Central

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz–1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium. PMID:26739504

  18. Acoustic sand detector for fluid flowstreams

    DOEpatents

    Beattie, Alan G.; Bohon, W. Mark

    1993-01-01

    The particle volume and particle mass production rate of particulate solids entrained in fluid flowstreams such as formation sand or fracture proppant entrained in oil and gas production flowstreams is determined by a system having a metal probe interposed in a flow conduit for transmitting acoustic emissions created by particles impacting the probe to a sensor and signal processing circuit which produces discrete signals related to the impact of each of the particles striking the probe. The volume or mass flow rate of particulates is determined from making an initial particle size distribution and particle energy distribution and comparing the initial energy distribution and/or the initial size distribution with values related to the impact energies of a predetermined number of recorded impacts. The comparison is also used to recalibrate the system to compensate for changes in flow velocity.

  19. Potentiation of the startle reflex is in line with contingency reversal instructions rather than the conditioning history.

    PubMed

    Mertens, Gaëtan; De Houwer, Jan

    2016-01-01

    In the context of fear conditioning, different psychophysiological measures have been related to different learning processes. Specifically, skin conductance responses (SCRs) have been related to cognitive expectancy learning, while fear potentiated startle (FPS) has been proposed to reflect affective learning that operates according to simple associative learning principles. On the basis of this two level account of fear conditioning we predicted that FPS should be less affected by verbal instructions and more affected by direct experience than SCRs. We tested this hypothesis by informing participants that contingencies would be reversed after a differential conditioning phase. Our results indicate that contingency reversal instructions led to an immediate and complete reversal of FPS regardless of the previous conditioning history. This change was accompanied by similar changes on US expectancy ratings and SCRs. These results conform with an expectancy model of fear conditioning but argue against a two level account of fear conditioning.

  20. Impaired acquisition of classically conditioned fear-potentiated startle reflexes in humans with focal bilateral basolateral amygdala damage

    PubMed Central

    Morgan, Barak; Terburg, David; Stein, Dan J.; van Honk, Jack

    2015-01-01

    Based on studies in rodents, the basolateral amygdala (BLA) is considered a key site for experience-dependent neural plasticity underlying the acquisition of conditioned fear responses. In humans, very few studies exist of subjects with selective amygdala lesions and those studies have only implicated the amygdala more broadly leaving the role of amygdala sub-regions underexplored. We tested a rare sample of subjects (N = 4) with unprecedented focal bilateral BLA lesions due to a genetic condition called Urbach–Wiethe disease. In a classical delay fear conditioning experiment, these subjects showed impaired acquisition of conditioned fear relative to a group of matched control subjects (N = 10) as measured by fear-potentiation of the defensive eye-blink startle reflex. After the experiment, the BLA-damaged cases showed normal declarative memory of the conditioned association. Our findings provide new evidence that the human BLA is essential to drive fast classically conditioned defensive reflexes. PMID:25552573

  1. Maturation of the human fetal startle response: Evidence for sex-specific maturation of the human fetus1

    PubMed Central

    Buss, Claudia; Davis, Elysia Poggi; Class, Quetzal A.; Gierczak, Matt; Pattillo, Carol; Glynn, Laura M.; Sandman, Curt A.

    2009-01-01

    Despite the evidence for early fetal experience exerting programming influences on later neurological development and health risk, very few prospective studies of human fetal behavior have been reported. In a prospective longitudinal study, fetal nervous system maturation was serially assessed by monitoring fetal heart rate (FHR) responses to vibroacoustic stimulation (VAS) in 191 maternal/fetal dyads. Responses were not detected at 26 weeks gestational age (GA). Sex-specific, age-characteristic changes in the FHR response to VAS were observed by 31 weeks’ GA. Males showed larger responses and continued to exhibit maturational changes until 37 weeks’ GA, females however, presented with a mature FHR startle response by 31 weeks’ GA. The results indicate that there are different rates of maturation in the male and female fetus that may have implications for sex-specific programming influences. PMID:19726143

  2. Optical fiber photoacoustic-photothermal probe.

    PubMed

    Beard, P C; Pérennès, F; Draguioti, E; Mills, T N

    1998-08-01

    We describe the operation of an all-optical probe that provides an alternative means of implementing photoacoustic and photothermal investigative techniques, particularly those used in biomedical applications. The probe is based on a transparent, acoustically and thermally sensitive Fabry-Perot polymer film sensor mounted at the end of an optical fiber. We demonstrate the ability of the system to make photoacoustic and photothermal measurements simultaneously and evaluate its photothermal response, using a nonscattering liquid target of known and adjustable absorption coefficient. The acoustic and thermal noise floors were 2 kPa and 6 x 10(-3) degrees C , respectively, obtained over a 25-MHz measurement bandwidth and 30 signal averages.

  3. Subsurface defect of amorphous carbon film imaged by near field acoustic microscopy

    NASA Astrophysics Data System (ADS)

    Zeng, J. T.; Zhao, K. Y.; Zeng, H. R.; Song, H. Z.; Zheng, L. Y.; Li, G. R.; Yin, Q. R.

    2008-05-01

    Amorphous carbon films were examined by low frequency scanning-probe acoustic microscopy (LF-SPAM). Local elastic properties as well as topography were imaged in the acoustic mode. Two kinds of subsurface defects were revealed by the LF-SPAM method. The influence of the subsurface defects on the elastic properties was also discussed. The ability to image subsurface defects was dependent on the scan area and the scan speed. Our results showed that the low frequency scanning-probe acoustic microscopy is a useful method for imaging subsurface defects with high resolution.

  4. The Acoustical Environment.

    ERIC Educational Resources Information Center

    Smith, Melissa

    Asserting that without an adequate acoustical environment, learning activities can be hindered, this paper reviews the literature on classroom acoustics, particularly noise, reverberation, signal-to-noise ratio, task performance, and recommendations for improvement. Through this review, the paper seeks to determine whether portable classrooms…

  5. Cystic acoustic schwannomas.

    PubMed

    Lunardi, P; Missori, P; Mastronardi, L; Fortuna, A

    1991-01-01

    Three cases with large space-occupying cysts in the cerebellopontine angle are reported. CT and MRI findings were not typical for acoustic schwannomas but at operation, besides the large cysts, small acoustic schwannomas could be detected and removed. The clinical and neuroradiological features of this unusual variety and the CT and MRI differential diagnosis of cerebellopontine angle lesions are discussed.

  6. Acoustic Remote Sensing

    NASA Astrophysics Data System (ADS)

    Dowling, David R.; Sabra, Karim G.

    2015-01-01

    Acoustic waves carry information about their source and collect information about their environment as they propagate. This article reviews how these information-carrying and -collecting features of acoustic waves that travel through fluids can be exploited for remote sensing. In nearly all cases, modern acoustic remote sensing involves array-recorded sounds and array signal processing to recover multidimensional results. The application realm for acoustic remote sensing spans an impressive range of signal frequencies (10-2 to 107 Hz) and distances (10-2 to 107 m) and involves biomedical ultrasound imaging, nondestructive evaluation, oil and gas exploration, military systems, and Nuclear Test Ban Treaty monitoring. In the past two decades, approaches have been developed to robustly localize remote sources; remove noise and multipath distortion from recorded signals; and determine the acoustic characteristics of the environment through which the sound waves have traveled, even when the recorded sounds originate from uncooperative sources or are merely ambient noise.

  7. Acoustic suspension system

    NASA Technical Reports Server (NTRS)

    Lee, M. C.; Wang, T. G. (Inventor)

    1983-01-01

    An acoustic levitation system is described, with single acoustic source and a small reflector to stably levitate a small object while the object is processed as by coating or heating it. The system includes a concave acoustic source which has locations on opposite sides of its axis that vibrate towards and away from a focal point to generate a converging acoustic field. A small reflector is located near the focal point, and preferably slightly beyond it, to create an intense acoustic field that stably supports a small object near the reflector. The reflector is located about one-half wavelength from the focal point and is concavely curved to a radius of curvature (L) of about one-half the wavelength, to stably support an object one-quarter wavelength (N) from the reflector.

  8. Virtual acoustics displays

    NASA Technical Reports Server (NTRS)

    Wenzel, Elizabeth M.; Fisher, Scott S.; Stone, Philip K.; Foster, Scott H.

    1991-01-01

    The real time acoustic display capabilities are described which were developed for the Virtual Environment Workstation (VIEW) Project at NASA-Ames. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditory symbology, a related collection of representational auditory 'objects' or 'icons', can be designed using ACE (Auditory Cue Editor), which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with 3-D visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events.

  9. Cochlear bionic acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Fu, Gang; Bai, Changan

    2014-11-01

    A design of bionic acoustic metamaterial and acoustic functional devices was proposed by employing the mammalian cochlear as a prototype. First, combined with the experimental data in previous literatures, it is pointed out that the cochlear hair cells and stereocilia cluster are a kind of natural biological acoustic metamaterials with the negative stiffness characteristics. Then, to design the acoustic functional devices conveniently in engineering application, a simplified parametric helical structure was proposed to replace actual irregular cochlea for bionic design, and based on the computational results of such a bionic parametric helical structure, it is suggested that the overall cochlear is a local resonant system with the negative dynamic effective mass characteristics. There are many potential applications in the bandboard energy recovery device, cochlear implant, and acoustic black hole.

  10. Acoustic integrated extinction

    PubMed Central

    Norris, Andrew N.

    2015-01-01

    The integrated extinction (IE) is defined as the integral of the scattering cross section as a function of wavelength. Sohl et al. (2007 J. Acoust. Soc. Am. 122, 3206–3210. (doi:10.1121/1.2801546)) derived an IE expression for acoustic scattering that is causal, i.e. the scattered wavefront in the forward direction arrives later than the incident plane wave in the background medium. The IE formula was based on electromagnetic results, for which scattering is causal by default. Here, we derive a formula for the acoustic IE that is valid for causal and non-causal scattering. The general result is expressed as an integral of the time-dependent forward scattering function. The IE reduces to a finite integral for scatterers with zero long-wavelength monopole and dipole amplitudes. Implications for acoustic cloaking are discussed and a new metric is proposed for broadband acoustic transparency. PMID:27547100

  11. Direct Field Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Larkin, Paul; Goldstein, Bob

    2008-01-01

    This paper presents an update to the methods and procedures used in Direct Field Acoustic Testing (DFAT). The paper will discuss some of the recent techniques and developments that are currently being used and the future publication of a reference standard. Acoustic testing using commercial sound system components is becoming a popular and cost effective way of generating a required acoustic test environment both in and out of a reverberant chamber. This paper will present the DFAT test method, the usual setup and procedure and the development and use of a closed-loop, narrow-band control system. Narrow-band control of the acoustic PSD allows all standard techniques and procedures currently used in random control to be applied to acoustics and some examples are given. The paper will conclude with a summary of the development of a standard practice guideline that is hoped to be available in the first quarter of next year.

  12. Virtual acoustics displays

    NASA Astrophysics Data System (ADS)

    Wenzel, Elizabeth M.; Fisher, Scott S.; Stone, Philip K.; Foster, Scott H.

    1991-03-01

    The real time acoustic display capabilities are described which were developed for the Virtual Environment Workstation (VIEW) Project at NASA-Ames. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditory symbology, a related collection of representational auditory 'objects' or 'icons', can be designed using ACE (Auditory Cue Editor), which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with 3-D visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events.

  13. Measurement of food texture by an acoustic vibration method

    NASA Astrophysics Data System (ADS)

    Sakurai, Naoki; Taniwaki, Mitsuru; Iwatani, Shin-ichiro; Akimoto, Hidemi

    2011-09-01

    Food texture was measured by a new acoustic vibration method. A piezoelectric sensor sandwiched between a probe and piston was inserted into a food sample by delivery of silicon oil to a cylinder by a pump. Vibration emitted from the food sample on insertion of the probe was monitored by voltage outputs of the sensor. The voltage signals were passed through 19 half octave bands to calculate texture index for each band. The texture index was defined as vibration energy of the probe caused by the food rupture and/or breakage per unit time.

  14. Acoustic solitons: A robust tool to investigate the generation and detection of ultrafast acoustic waves

    NASA Astrophysics Data System (ADS)

    Péronne, Emmanuel; Chuecos, Nicolas; Thevenard, Laura; Perrin, Bernard

    2017-02-01

    Solitons are self-preserving traveling waves of great interest in nonlinear physics but hard to observe experimentally. In this report an experimental setup is designed to observe and characterize acoustic solitons in a GaAs(001) substrate. It is based on careful temperature control of the sample and an interferometric detection scheme. Ultrashort acoustic solitons, such as the one predicted by the Korteweg-de Vries equation, are observed and fully characterized. Their particlelike nature is clearly evidenced and their unique properties are thoroughly checked. The spatial averaging of the soliton wave front is shown to account for the differences between the theoretical and experimental soliton profile. It appears that ultrafast acoustic experiments provide a precise measurement of the soliton velocity. It allows for absolute calibration of the setup as well as the response function analysis of the detection layer. Moreover, the temporal distribution of the solitons is also analyzed with the help of the inverse scattering method. It shows how the initial acoustic pulse profile which gives birth to solitons after nonlinear propagation can be retrieved. Such investigations provide a new tool to probe transient properties of highly excited matter through the study of the emitted acoustic pulse after laser excitation.

  15. Development of the Acoustically Evoked Behavioral Response in Larval Plainfin Midshipman Fish, Porichthys notatus

    PubMed Central

    Alderks, Peter W.; Sisneros, Joseph A.

    2013-01-01

    The ontogeny of hearing in fishes has become a major interest among bioacoustics researchers studying fish behavior and sensory ecology. Most fish begin to detect acoustic stimuli during the larval stage which can be important for navigation, predator avoidance and settlement, however relatively little is known about the hearing capabilities of larval fishes. We characterized the acoustically evoked behavioral response (AEBR) in the plainfin midshipman fish, Porichthys notatus, and used this innate startle-like response to characterize this species' auditory capability during larval development. Age and size of larval midshipman were highly correlated (r2 = 0.92). The AEBR was first observed in larvae at 1.4 cm TL. At a size ≥1.8 cm TL, all larvae responded to a broadband stimulus of 154 dB re1 µPa or −15.2 dB re 1 g (z-axis). Lowest AEBR thresholds were 140–150 dB re 1 µPa or −33 to −23 dB re 1 g for frequencies below 225 Hz. Larval fish with size ranges of 1.9–2.4 cm TL had significantly lower best evoked frequencies than the other tested size groups. We also investigated the development of the lateral line organ and its function in mediating the AEBR. The lateral line organ is likely involved in mediating the AEBR but not necessary to evoke the startle-like response. The midshipman auditory and lateral line systems are functional during early development when the larvae are in the nest and the auditory system appears to have similar tuning characteristics throughout all life history stages. PMID:24340003

  16. Data Management Techniques for Acoustical Planetary Data

    NASA Astrophysics Data System (ADS)

    Eichelberger, Hans; Prattes, Gustav; Schwingenschuh, Konrad; Tokano, T.; Jernej, I.; Stachel, Manfred; Besser, B. P.; Aydogar, Oe.

    We discuss data management techniques for acoustical data obtained from future atmospheric planetary in-situ probes with the aim of event oriented scientific analysis. The immediate objec-tive is the localisation (acoustic wave telescope) and characterisation of acoustic phenomena of atmospheres and surfaces, e.g. in the frame of the proposed NASA/ESA Titan Saturn System Mission (TSSM) with the Acoustic Sensor Package (ACU) multi-microphone array. Contrary to huge amounts of source data obtained through the electromagnetic windows, acoustical sig-nals are seldom recorded and few files exist. One example is pressure sensor data from the instrument HASI/PWA during Huygens descent, mission Cassini-Huygens. Nevertheless, a lot of acoustic point and noise sources, e.g. caused by rain, drizzle or wind abound in Titan's atmosphere. In almost all cases, due to limitations in telemetry rate, a careful strategy for onboard event handling and data reduction -the first step in data management -has to be selected, e.g. sampling rates in kHz range or averaging in the frequency domain. This pre-processing together with complementary investigations at the space segment directly influences the scientific data return in terms of long-term continuous or short-term event based studies. The database at the ground segment with science data and metadata entries after final calibra-tion has to support the combined investigations with other instruments. This second step in data management fully explores the acoustic environment of planetary atmospheres in terms of background noise and spacecraft generated disturbances, location and characterisation of source regions and correlation between the experiments. Currently we're running databases for magnetic field data from various ground-based and satellite related experiments, historical balloon data included. Comparisons of data between experiments are possible. This framework based on dependability considerations with several different

  17. Acoustic mapping velocimetry

    NASA Astrophysics Data System (ADS)

    Muste, M.; Baranya, S.; Tsubaki, R.; Kim, D.; Ho, H.; Tsai, H.; Law, D.

    2016-05-01

    Knowledge of sediment dynamics in rivers is of great importance for various practical purposes. Despite its high relevance in riverine environment processes, the monitoring of sediment rates remains a major and challenging task for both suspended and bed load estimation. While the measurement of suspended load is currently an active area of testing with nonintrusive technologies (optical and acoustic), bed load measurement does not mark a similar progress. This paper describes an innovative combination of measurement techniques and analysis protocols that establishes the proof-of-concept for a promising technique, labeled herein Acoustic Mapping Velocimetry (AMV). The technique estimates bed load rates in rivers developing bed forms using a nonintrusive measurements approach. The raw information for AMV is collected with acoustic multibeam technology that in turn provides maps of the bathymetry over longitudinal swaths. As long as the acoustic maps can be acquired relatively quickly and the repetition rate for the mapping is commensurate with the movement of the bed forms, successive acoustic maps capture the progression of the bed form movement. Two-dimensional velocity maps associated with the bed form migration are obtained by implementing algorithms typically used in particle image velocimetry to acoustic maps converted in gray-level images. Furthermore, use of the obtained acoustic and velocity maps in conjunction with analytical formulations (e.g., Exner equation) enables estimation of multidirectional bed load rates over the whole imaged area. This paper presents a validation study of the AMV technique using a set of laboratory experiments.

  18. Acoustic cooling engine

    DOEpatents

    Hofler, Thomas J.; Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1988-01-01

    An acoustic cooling engine with improved thermal performance and reduced internal losses comprises a compressible fluid contained in a resonant pressure vessel. The fluid has a substantial thermal expansion coefficient and is capable of supporting an acoustic standing wave. A thermodynamic element has first and second ends and is located in the resonant pressure vessel in thermal communication with the fluid. The thermal response of the thermodynamic element to the acoustic standing wave pumps heat from the second end to the first end. The thermodynamic element permits substantial flow of the fluid through the thermodynamic element. An acoustic driver cyclically drives the fluid with an acoustic standing wave. The driver is at a location of maximum acoustic impedance in the resonant pressure vessel and proximate the first end of the thermodynamic element. A hot heat exchanger is adjacent to and in thermal communication with the first end of the thermodynamic element. The hot heat exchanger conducts heat from the first end to portions of the resonant pressure vessel proximate the hot heat exchanger. The hot heat exchanger permits substantial flow of the fluid through the hot heat exchanger. The resonant pressure vessel can include a housing less than one quarter wavelength in length coupled to a reservoir. The housing can include a reduced diameter portion communicating with the reservoir. The frequency of the acoustic driver can be continuously controlled so as to maintain resonance.

  19. Acoustic sniper localization system

    NASA Astrophysics Data System (ADS)

    Prado, Gervasio; Dhaliwal, Hardave; Martel, Philip O.

    1997-02-01

    Technologies for sniper localization have received increased attention in recent months as American forces have been deployed to various trouble spots around the world. Among the technologies considered for this task acoustics is a natural choice for various reasons. The acoustic signatures of gunshots are loud and distinctive, making them easy to detect even in high noise background environments. Acoustics provides a passive sensing technology with excellent range and non line of sight capabilities. Last but not least, an acoustic sniper location system can be built at a low cost with off the shelf components. Despite its many advantages, the performance of acoustic sensors can degrade under adverse propagation conditions. Localization accuracy, although good, is usually not accurate enough to pinpoint a sniper's location in some scenarios (for example which widow in a building or behind which tree in a grove). For these more demanding missions, the acoustic sensor can be used in conjunction with an infra red imaging system that detects the muzzle blast of the gun. The acoustic system can be used to cue the pointing system of the IR camera in the direction of the shot's source.

  20. Acoustic Noise Induces Attention Shifts and Reduces Foraging Performance in Three-Spined Sticklebacks (Gasterosteus aculeatus)

    PubMed Central

    Purser, Julia; Radford, Andrew N.

    2011-01-01

    Acoustic noise is known to have a variety of detrimental effects on many animals, including humans, but surprisingly little is known about its impacts on foraging behaviour, despite the obvious potential consequences for survival and reproductive success. We therefore exposed captive three-spined sticklebacks (Gasterosteus aculeatus) to brief and prolonged noise to investigate how foraging performance is affected by the addition of acoustic noise to an otherwise quiet environment. The addition of noise induced only mild fear-related behaviours - there was an increase in startle responses, but no change in the time spent freezing or hiding compared to a silent control - and thus had no significant impact on the total amount of food eaten. However, there was strong evidence that the addition of noise increased food-handling errors and reduced discrimination between food and non-food items, results that are consistent with a shift in attention. Consequently, noise resulted in decreased foraging efficiency, with more attacks needed to consume the same number of prey items. Our results suggest that acoustic noise has the potential to influence a whole host of everyday activities through effects on attention, and that even very brief noise exposure can cause functionally significant impacts, emphasising the threat posed by ever-increasing levels of anthropogenic noise in the environment. PMID:21386909

  1. The room acoustic rendering equation.

    PubMed

    Siltanen, Samuel; Lokki, Tapio; Kiminki, Sami; Savioja, Lauri

    2007-09-01

    An integral equation generalizing a variety of known geometrical room acoustics modeling algorithms is presented. The formulation of the room acoustic rendering equation is adopted from computer graphics. Based on the room acoustic rendering equation, an acoustic radiance transfer method, which can handle both diffuse and nondiffuse reflections, is derived. In a case study, the method is used to predict several acoustic parameters of a room model. The results are compared to measured data of the actual room and to the results given by other acoustics prediction software. It is concluded that the method can predict most acoustic parameters reliably and provides results as accurate as current commercial room acoustic prediction software. Although the presented acoustic radiance transfer method relies on geometrical acoustics, it can be extended to model diffraction and transmission through materials in future.

  2. PRSEUS Acoustic Panel Fabrication

    NASA Technical Reports Server (NTRS)

    Nicolette, Velicki; Yovanof, Nicolette P.; Baraja, Jaime; Mathur, Gopal; Thrash, Patrick; Pickell, Robert

    2011-01-01

    This report describes the development of a novel structural concept, Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS), that addresses the demanding fuselage loading requirements for the Hybrid Wing or Blended Wing Body (BWB) airplane configuration with regards to acoustic response. A PRSEUS panel was designed and fabricated and provided to NASA-LaRC for acoustic response testing in the Structural Acoustics Loads and Transmission (SALT) facility). Preliminary assessments of the sound transmission characteristics of a PRSEUS panel subjected to a representative Hybrid Wing Body (HWB) operating environment were completed for the NASA Environmentally Responsible Aviation (ERA) Program.

  3. Acoustic well cleaner

    DOEpatents

    Maki, Jr., Voldi E.; Sharma, Mukul M.

    1997-01-21

    A method and apparatus are disclosed for cleaning the wellbore and the near wellbore region. A sonde is provided which is adapted to be lowered into a borehole and which includes a plurality of acoustic transducers arranged around the sonde. Electrical power provided by a cable is converted to acoustic energy. The high intensity acoustic energy directed to the borehole wall and into the near wellbore region, redissolves or resuspends the material which is reducing the permeability of the formation and/or restricting flow in the wellbore.

  4. Acoustical heat pumping engine

    DOEpatents

    Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium.

  5. Acoustical heat pumping engine

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium. 2 figs.

  6. A rare case of alcoholic pellagra encephalopathy with startle myoclonus and marked response to niacin therapy: time for a new dictum?

    PubMed

    Sharma, Bhawna; Sannegowda, Raghavendra Bakki; Jain, Rahul; Dubey, Parul; Prakash, Swayam

    2013-04-22

    We report a case of 56-year-old man, chronic alcoholic, presented to us with progressive weakness in all the four limbs with stiffness and gait disturbance since 1-year associated with cognitive impairment. On examination he had mild confusion, spastic quadriparesis with brisk reflexes, extensor plantars and cerebellar features. During the hospital stay myoclonus was noticed in the patient, which was startle in nature. He did not have dermatitis, ascites or any stigmata of liver failure. MRI of brain revealed bilateral subdural effusion, left focal subarachnoid haemorrhage at perisylvian area and diffuse cortical atrophy. He was treated with supportive measures including thiamine with which his condition worsened. His serum niacin was low. With a possibility of alcoholic pellagra encephalopathy (APE) the patient was treated with niacin. His clinical condition improved drastically over next 1 week and startle myoclonus disappeared, favouring the diagnosis of APE though multiple confounding factors were present.

  7. Acoustic imaging system

    DOEpatents

    Smith, Richard W.

    1979-01-01

    An acoustic imaging system for displaying an object viewed by a moving array of transducers as the array is pivoted about a fixed point within a given plane. A plurality of transducers are fixedly positioned and equally spaced within a laterally extending array and operatively directed to transmit and receive acoustic signals along substantially parallel transmission paths. The transducers are sequentially activated along the array to transmit and receive acoustic signals according to a preestablished sequence. Means are provided for generating output voltages for each reception of an acoustic signal, corresponding to the coordinate position of the object viewed as the array is pivoted. Receptions from each of the transducers are presented on the same display at coordinates corresponding to the actual position of the object viewed to form a plane view of the object scanned.

  8. Compact acoustic refrigerator

    SciTech Connect

    Bennett, G.A.

    1991-12-31

    This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.

  9. Acoustic borehole logging

    SciTech Connect

    Medlin, W.L.; Manzi, S.J.

    1990-10-09

    This patent describes an acoustic borehole logging method. It comprises traversing a borehole with a borehole logging tool containing a transmitter of acoustic energy having a free-field frequency spectrum with at least one characteristic resonant frequency of vibration and spaced-apart receiver, repeatedly exciting the transmitter with a swept frequency tone burst of a duration sufficiently greater than the travel time of acoustic energy between the transmitter and the receiver to allow borehole cavity resonances to be established within the borehole cavity formed between the borehole logging tool and the borehole wall, detecting acoustic energy amplitude modulated by the borehole cavity resonances with the spaced-apart receiver, and recording an amplitude verses frequency output of the receiver in correlation with depth as a log of the borehole frequency spectrum representative of the subsurface formation comprising the borehole wall.

  10. Acoustic imaging system

    NASA Technical Reports Server (NTRS)

    Kendall, J. M., Jr.

    1977-01-01

    Tool detects noise sources by scanning sound "scene" and displaying relative location of noise-producing elements in area. System consists of ellipsoidal acoustic mirror and microphone and a display device.

  11. Compact acoustic refrigerator

    DOEpatents

    Bennett, G.A.

    1992-11-24

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

  12. Compact acoustic refrigerator

    DOEpatents

    Bennett, Gloria A.

    1992-01-01

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

  13. Acoustic bubble traps

    NASA Astrophysics Data System (ADS)

    Geisler, Reinhard; Kurz, Thomas; Lauterborn, Werner

    2000-07-01

    A small, oscillating bubble in a liquid can be trapped in the antinode of an acoustic standing wave field. Bubble stability is required for the study of single bubble sonoluminescence (SBSL). The properties of the acoustic resonator are essential for the stable trapping of sonoluminescing bubbles. Resonators can be chosen according to the intended application: size and geometry can be varied in a wide range. In this work, the acoustic responses of different resonators were measured by means of holographic interferometry, hydrophones and a laser vibrometer. Also, high-speed photography was used to observe the bubble dynamics. Several single, stable sonoluminescent bubbles were trapped simultaneously within an acoustic resonator in the pressure antinodes of a higher harmonic mode (few bubble sonoluminescence, FBSL).

  14. Department of Cybernetic Acoustics

    NASA Astrophysics Data System (ADS)

    The development of the theory, instrumentation and applications of methods and systems for the measurement, analysis, processing and synthesis of acoustic signals within the audio frequency range, particularly of the speech signal and the vibro-acoustic signal emitted by technical and industrial equipments treated as noise and vibration sources was discussed. The research work, both theoretical and experimental, aims at applications in various branches of science, and medicine, such as: acoustical diagnostics and phoniatric rehabilitation of pathological and postoperative states of the speech organ; bilateral ""man-machine'' speech communication based on the analysis, recognition and synthesis of the speech signal; vibro-acoustical diagnostics and continuous monitoring of the state of machines, technical equipments and technological processes.

  15. Basic Linear Acoustics

    NASA Astrophysics Data System (ADS)

    Pierce, Alan D.

    This chapter deals with the physical and mathematical aspects of sound when the disturbances are, in some sense, small. Acoustics is usually concerned with small-amplitude phenomena, and consequently a linear description is usually acoustics applicable. Disturbances are governed by the properties of the medium in which they occur, and the governing equations are the equations of continuum mechanics, which apply equally to gases, liquids, and solids. These include the mass, momentum, and energy equations, as well as thermodynamic principles. The viscosity and thermal conduction enter into the versions of these equations that apply to fluids. Fluids of typical great interest are air and sea water, and consequently this chapter includes a summary of their relevant acoustic properties. The foundation is also laid for the consideration of acoustic waves in elastic solids, suspensions, bubbly liquids, and porous media.

  16. Acoustics lecturing in Mexico

    NASA Astrophysics Data System (ADS)

    Beristain, Sergio

    2002-11-01

    Some thirty years ago acoustics lecturing started in Mexico at the National Polytechnic Institute in Mexico City, as part of the Bachelor of Science degree in Communications and Electronics Engineering curricula, including the widest program on this field in the whole country. This program has been producing acoustics specialists ever since. Nowadays many universities and superior education institutions around the country are teaching students at the B.Sc. level and postgraduate level many topics related to acoustics, such as Architectural Acoustics, Seismology, Mechanical Vibrations, Noise Control, Audio, Audiology, Music, etc. Also many institutions have started research programs in related fields, with participation of medical doctors, psychologists, musicians, engineers, etc. Details will be given on particular topics and development.

  17. Acoustic Neuroma Association

    MedlinePlus

    ... this sponsor... Platinum Sponsor More from this sponsor... Gold Sponsor University of Colorado Acoustic Neuroma Program Rocky Mountain Gamma Knife Center More from this sponsor... Gold Sponsor NYU Langone Medical Center Departments of Neurosurgery ...

  18. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface

    NASA Astrophysics Data System (ADS)

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A.

    2014-11-01

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell’s law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

  19. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface.

    PubMed

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A

    2014-11-24

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell's law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

  20. In the Blink of an Eye: Investigating the Role of Awareness in Fear Responding by Measuring the Latency of Startle Potentiation

    PubMed Central

    Åsli, Ole; Flaten, Magne A.

    2012-01-01

    The latency of startle reflex potentiation may shed light on the aware and unaware processes underlying associative learning, especially associative fear learning. We review research suggesting that single-cue delay classical conditioning is independent of awareness of the contingency between the conditioned stimulus (CS) and the unconditioned stimulus (US). Moreover, we discuss research that argues that conditioning independent of awareness has not been proven. Subsequently, three studies from our lab are presented that have investigated the role of awareness in classical conditioning, by measuring the minimum latency from CS onset to observed changes in reflexive behavior. In sum, research using this method shows that startle is potentiated 30 to 100 ms after CS onset following delay conditioning. Following trace fear conditioning, startle is potentiated 1500 ms after CS presentation. These results indicate that the process underlying delay conditioned responding is independent of awareness, and that trace fear conditioned responding is dependent on awareness. Finally, this method of investigating the role of awareness is discussed and future research possibilities are proposed. PMID:24962686

  1. Evidence that Illness-Compatible Cues Are Rewarding in Women Recovered from Anorexia Nervosa: A Study of the Effects of Dopamine Depletion on Eye-Blink Startle Responses

    PubMed Central

    O’Hara, Caitlin B.; Keyes, Alexandra; Renwick, Bethany; Giel, Katrin E.; Campbell, Iain C.; Schmidt, Ulrike

    2016-01-01

    In anorexia nervosa (AN), motivational salience is attributed to illness-compatible cues (e.g., underweight and active female bodies) and this is hypothesised to involve dopaminergic reward circuitry. We investigated the effects of reducing dopamine (DA) transmission on the motivational processing of AN-compatible cues in women recovered from AN (AN REC, n = 17) and healthy controls (HC, n = 15). This involved the acute phenylalanine and tyrosine depletion (APTD) procedure and a startle eye-blink modulation (SEM) task. In a balanced amino acid state, AN REC showed an increased appetitive response (decreased startle potentiation) to illness-compatible cues (underweight and active female body pictures (relative to neutral and non-active cues, respectively)). The HC had an aversive response (increased startle potentiation) to the same illness-compatible stimuli (relative to neutral cues). Importantly, these effects, which may be taken to resemble symptoms observed in the acute stage of illness and healthy behaviour respectively, were not present when DA was depleted. Thus, AN REC implicitly appraised underweight and exercise cues as more rewarding than did HC and the process may, in part, be DA-dependent. It is proposed that the positive motivational salience attributed to cues of emaciation and physical activity is, in part, mediated by dopaminergic reward processes and this contributes to illness pathology. These observations are consistent with the proposal that, in AN, aberrant reward-based learning contributes to the development of habituation of AN-compatible behaviours. PMID:27764214

  2. Ocean Acoustic Observatory Federation

    DTIC Science & Technology

    2001-09-30

    J., C. G. Fox, and F. K. Duennebier, Hydroacoustic detection of submarine landslides on Kilauea volcano , Geophys. Res. Lett., vol. 28, 1811-1814...acoustic tomography experiments in the vicinity of coastal North America, • Monitor, in real time, marine mammals, earthquakes and volcanoes in the...distances, coastal tomography and thermometry, and earthquakes and volcanoes in the northern Pacific. APPROACH The members of the Ocean Acoustic

  3. Numerical Techniques in Acoustics

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J. (Compiler)

    1985-01-01

    This is the compilation of abstracts of the Numerical Techniques in Acoustics Forum held at the ASME's Winter Annual Meeting. This forum was for informal presentation and information exchange of ongoing acoustic work in finite elements, finite difference, boundary elements and other numerical approaches. As part of this forum, it was intended to allow the participants time to raise questions on unresolved problems and to generate discussions on possible approaches and methods of solution.

  4. Directional Acoustic Density Sensor

    DTIC Science & Technology

    2010-09-13

    fluctuations of fluid density at a point . (2) DESCRIPTION OF THE PRIOR ART [0004] Conventional vector sensors measure particle velocity, v (vx,Vytvz...dipole-type or first order sensor that is realized by measuring particle velocity at a point , (which is the vector sensor sensing approach for...underwater sensors), or by measuring the gradient of the acoustic pressure at two closely spaced (less than the wavelength of an acoustic wave) points as it

  5. Low Frequency Acoustics

    DTIC Science & Technology

    2016-06-13

    with NOAA , ONR is providing technical services that will help establish a baseline for assessment of long- term VLF acoustic trends in selected...ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 sponsored by NOAA , was added to the...with NOAA (NMFS) and other parties has dealt with ocean acoustics related to issues stimulated by the Marine Mammal Protection Act. A focal point has

  6. Ocean acoustic reverberation tomography.

    PubMed

    Dunn, Robert A

    2015-12-01

    Seismic wide-angle imaging using ship-towed acoustic sources and networks of ocean bottom seismographs is a common technique for exploring earth structure beneath the oceans. In these studies, the recorded data are dominated by acoustic waves propagating as reverberations in the water column. For surveys with a small receiver spacing (e.g., <10 km), the acoustic wave field densely samples properties of the water column over the width of the receiver array. A method, referred to as ocean acoustic reverberation tomography, is developed that uses the travel times of direct and reflected waves to image ocean acoustic structure. Reverberation tomography offers an alternative approach for determining the structure of the oceans and advancing the understanding of ocean heat content and mixing processes. The technique has the potential for revealing small-scale ocean thermal structure over the entire vertical height of the water column and along long survey profiles or across three-dimensional volumes of the ocean. For realistic experimental geometries and data noise levels, the method can produce images of ocean sound speed on a smaller scale than traditional acoustic tomography.

  7. Coupling between ion-acoustic waves and neutrino oscillations.

    PubMed

    Haas, Fernando; Pascoal, Kellen Alves; Mendonça, José Tito

    2017-01-01

    The work investigates the coupling between ion-acoustic waves and neutrino flavor oscillations in a nonrelativistic electron-ion plasma under the influence of a mixed neutrino beam. Neutrino oscillations are mediated by the flavor polarization vector dynamics in a material medium. The linear dispersion relation around homogeneous static equilibria is developed. When resonant with the ion-acoustic mode, the neutrino flavor oscillations can transfer energy to the plasma exciting a new fast unstable mode in extreme astrophysical scenarios. The growth rate and the unstable wavelengths are determined in typical type II supernova parameters. The predictions can be useful for a new indirect probe on neutrino oscillations in nature.

  8. Coupling between ion-acoustic waves and neutrino oscillations

    NASA Astrophysics Data System (ADS)

    Haas, Fernando; Pascoal, Kellen Alves; Mendonça, José Tito

    2017-01-01

    The work investigates the coupling between ion-acoustic waves and neutrino flavor oscillations in a nonrelativistic electron-ion plasma under the influence of a mixed neutrino beam. Neutrino oscillations are mediated by the flavor polarization vector dynamics in a material medium. The linear dispersion relation around homogeneous static equilibria is developed. When resonant with the ion-acoustic mode, the neutrino flavor oscillations can transfer energy to the plasma exciting a new fast unstable mode in extreme astrophysical scenarios. The growth rate and the unstable wavelengths are determined in typical type II supernova parameters. The predictions can be useful for a new indirect probe on neutrino oscillations in nature.

  9. Information gains from cosmological probes

    NASA Astrophysics Data System (ADS)

    Grandis, S.; Seehars, S.; Refregier, A.; Amara, A.; Nicola, A.

    2016-05-01

    In light of the growing number of cosmological observations, it is important to develop versatile tools to quantify the constraining power and consistency of cosmological probes. Originally motivated from information theory, we use the relative entropy to compute the information gained by Bayesian updates in units of bits. This measure quantifies both the improvement in precision and the `surprise', i.e. the tension arising from shifts in central values. Our starting point is a WMAP9 prior which we update with observations of the distance ladder, supernovae (SNe), baryon acoustic oscillations (BAO), and weak lensing as well as the 2015 Planck release. We consider the parameters of the flat ΛCDM concordance model and some of its extensions which include curvature and Dark Energy equation of state parameter w. We find that, relative to WMAP9 and within these model spaces, the probes that have provided the greatest gains are Planck (10 bits), followed by BAO surveys (5.1 bits) and SNe experiments (3.1 bits). The other cosmological probes, including weak lensing (1.7 bits) and {H0} measures (1.7 bits), have contributed information but at a lower level. Furthermore, we do not find any significant surprise when updating the constraints of WMAP9 with any of the other experiments, meaning that they are consistent with WMAP9. However, when we choose Planck15 as the prior, we find that, accounting for the full multi-dimensionality of the parameter space, the weak lensing measurements of CFHTLenS produce a large surprise of 4.4 bits which is statistically significant at the 8 σ level. We discuss how the relative entropy provides a versatile and robust framework to compare cosmological probes in the context of current and future surveys.

  10. Effects of acoustic noise on the auditory nerve compound action potentials evoked by electric pulse trains.

    PubMed

    Nourski, Kirill V; Abbas, Paul J; Miller, Charles A; Robinson, Barbara K; Jeng, Fuh-Cherng

    2005-04-01

    This study investigated the effects of acoustic noise on the auditory nerve compound action potentials in response to electric pulse trains. Subjects were adult guinea pigs, implanted with a minimally invasive electrode to preserve acoustic sensitivity. Electrically evoked compound action potentials (ECAP) were recorded from the auditory nerve trunk in response to electric pulse trains both during and after the presentation of acoustic white noise. Simultaneously presented acoustic noise produced a decrease in ECAP amplitude. The effect of the acoustic masker on the electric probe was greatest at the onset of the acoustic stimulus and it was followed by a partial recovery of the ECAP amplitude. Following cessation of the acoustic noise, ECAP amplitude recovered over a period of approximately 100-200 ms. The effects of the acoustic noise were more prominent at lower electric pulse rates (interpulse intervals of 3 ms and higher). At higher pulse rates, the ECAP adaptation to the electric pulse train alone was larger and the acoustic noise, when presented, produced little additional effect. The observed effects of noise on ECAP were the greatest at high electric stimulus levels and, for a particular electric stimulus level, at high acoustic noise levels.

  11. Analysis of acoustic and entropy disturbances in a hypersonic wind tunnel

    NASA Astrophysics Data System (ADS)

    Schilden, Thomas; Schröder, Wolfgang; Ali, Syed Raza Christopher; Schreyer, Anne-Marie; Wu, Jie; Radespiel, Rolf

    2016-05-01

    The tunnel noise in a Mach 5.9 Ludwieg tube is determined by two methods, a newly developed cone-probe-DNS method and a reliable hot-wire-Pitot-probe method. The new method combines pressure and heat flux measurements using a cone probe and direct numerical simulation (DNS). The modal analysis is based on transfer functions obtained by the DNS to link the measured quantities to the tunnel noise. The measurements are performed for several unit-Reynolds numbers in the range of 5 ṡ 106 ≤ Re/m ≤ 16 ṡ 106 and probe positions to identify the sensitivities of tunnel noise. The DNS solutions show similar response mechanisms of the cone probe to incident acoustic and entropy waves which leads to high condition numbers of the transfer matrix such that a unique relationship between response and source mechanism can be only determined by neglecting the contribution of the non-acoustic modes to the pressure and heat flux fluctuations. The results of the cone-probe-DNS method are compared to a modal analysis based on the hot-wire-Pitot-probe method which provides reliable results in the frequency range less than 50 kHz. In this low frequency range the findings of the two different mode analyses agree well. At higher frequencies, the newly developed cone-probe-DNS method is still valid. The tunnel noise is dominated by the acoustic mode, since the entropy mode is lower by one order of magnitude and the vorticity mode can be neglected. The acoustic mode is approximately 0.5% at 30 kHz and the cone-probe-DNS data illustrate the acoustic mode to decrease and to asymptotically approach 0.2%.

  12. Femtosecond nonlinear ultrasonics in gold probed with ultrashort surface plasmons.

    PubMed

    Temnov, Vasily V; Klieber, Christoph; Nelson, Keith A; Thomay, Tim; Knittel, Vanessa; Leitenstorfer, Alfred; Makarov, Denys; Albrecht, Manfred; Bratschitsch, Rudolf

    2013-01-01

    Fundamental interactions induced by lattice vibrations on ultrafast time scales have become increasingly important for modern nanoscience and technology. Experimental access to the physical properties of acoustic phonons in the terahertz-frequency range and over the entire Brillouin zone is crucial for understanding electric and thermal transport in solids and their compounds. Here we report on the generation and nonlinear propagation of giant (1 per cent) acoustic strain pulses in hybrid gold/cobalt bilayer structures probed with ultrafast surface plasmon interferometry. This new technique allows for unambiguous characterization of arbitrary ultrafast acoustic transients. The giant acoustic pulses experience substantial nonlinear reshaping after a propagation distance of only 100 nm in a crystalline gold layer. Excellent agreement with the Korteveg-de Vries model points to future quantitative nonlinear femtosecond terahertz-ultrasonics at the nano-scale in metals at room temperature.

  13. Eyelid contour detection and tracking for startle research related eye-blink measurements from high-speed video records.

    PubMed

    Bernard, Florian; Deuter, Christian Eric; Gemmar, Peter; Schachinger, Hartmut

    2013-10-01

    Using the positions of the eyelids is an effective and contact-free way for the measurement of startle induced eye-blinks, which plays an important role in human psychophysiological research. To the best of our knowledge, no methods for an efficient detection and tracking of the exact eyelid contours in image sequences captured at high-speed exist that are conveniently usable by psychophysiological researchers. In this publication a semi-automatic model-based eyelid contour detection and tracking algorithm for the analysis of high-speed video recordings from an eye tracker is presented. As a large number of images have been acquired prior to method development it was important that our technique is able to deal with images that are recorded without any special parametrisation of the eye tracker. The method entails pupil detection, specular reflection removal and makes use of dynamic model adaption. In a proof-of-concept study we could achieve a correct detection rate of 90.6%. With this approach, we provide a feasible method to accurately assess eye-blinks from high-speed video recordings.

  14. Fear-Potentiated Startle and Fear Extinction in a Sample of Undergraduate Women Exposed to a Campus Mass Shooting

    PubMed Central

    Orcutt, Holly K.; Hannan, Susan M.; Seligowski, Antonia V.; Jovanovic, Tanja; Norrholm, Seth D.; Ressler, Kerry J.; McCanne, Thomas

    2017-01-01

    Posttraumatic stress disorder (PTSD) is a common psychological disorder that affects a substantial minority of individuals. Previous research has suggested that PTSD can be partially explained as a disorder of impaired fear inhibition. The current study utilized a previously validated fear acquisition and extinction paradigm in a sample of 75 undergraduate women who were exposed to a campus mass shooting that occurred in 2008. We used a protocol in which conditioned fear was first acquired through the presentation of one colored shape (reinforced conditioned stimulus, CS+) that was paired with an aversive airblast to the larynx (unconditioned stimulus, US) and a different colored shape that was not paired with the airblast (non-reinforced conditioned stimulus, CS-). Fear was extinguished 10 min later through repeated presentations of the CSs without reinforcement. Number of clinically significant posttraumatic stress symptoms (PTSS) immediately following the mass shooting were positively associated with fear-potentiated startle (FPS) to the CS+ and CS- during late periods of acquisition. During early periods of fear extinction, PTSS was positively associated with FPS to the CS+. Results from the current study suggest that PTSS is related to altered fear inhibition and extinction during an FPS paradigm. In line with similar research, women with greater PTSS demonstrated a greater “fear load,” suggesting that these women experienced elevated fear to the CS+ during extinction after conditioned fear was acquired. PMID:28111559

  15. Embodying approach motivation: body posture influences startle eyeblink and event-related potential responses to appetitive stimuli.

    PubMed

    Price, Tom F; Dieckman, Laurtiz W; Harmon-Jones, Eddie

    2012-07-01

    Past research suggested that the motivational significance of images influences reflexive and electrocortical responses to those images (Briggs and Martin, 2009; Gard et al., 2007; Schupp et al., 2004), with erotica often exerting the largest effects for appetitive pictures (Grillon and Baas, 2003; Weinberg and Hajcak, 2010). This research paradigm, however, compares responses to different types of images (e.g., erotica vs. exciting sports scenes). This past motivational interpretation, therefore, would be further supported by experiments wherein appetitive picture content is held constant and motivational states are manipulated with a different method. In the present experiment, we tested the hypothesis that changes in physical postures associated with approach motivation influences reflexive and electrocortical responses to appetitive stimuli. Past research has suggested that bodily manipulations (e.g., facial expressions) play a role in emotion- and motivation-related physiology (Ekman and Davidson, 1993; Levenson et al., 1990). Extending these results, leaning forward (associated with a heightened urge to approach stimuli) relative to reclining (associated with less of an urge to approach stimuli) caused participants to have smaller startle eyeblink responses during appetitive, but not neutral, picture viewing. Leaning relative to reclining also caused participants to have larger LPPs to appetitive but not neutral pictures, and influenced ERPs as early as 100ms into stimulus viewing. This evidence suggests that body postures associated with approach motivation causally influence basic reflexive and electrocortical reactions to appetitive emotive stimuli.

  16. Fear-Potentiated Startle and Fear Extinction in a Sample of Undergraduate Women Exposed to a Campus Mass Shooting.

    PubMed

    Orcutt, Holly K; Hannan, Susan M; Seligowski, Antonia V; Jovanovic, Tanja; Norrholm, Seth D; Ressler, Kerry J; McCanne, Thomas

    2016-01-01

    Posttraumatic stress disorder (PTSD) is a common psychological disorder that affects a substantial minority of individuals. Previous research has suggested that PTSD can be partially explained as a disorder of impaired fear inhibition. The current study utilized a previously validated fear acquisition and extinction paradigm in a sample of 75 undergraduate women who were exposed to a campus mass shooting that occurred in 2008. We used a protocol in which conditioned fear was first acquired through the presentation of one colored shape (reinforced conditioned stimulus, CS+) that was paired with an aversive airblast to the larynx (unconditioned stimulus, US) and a different colored shape that was not paired with the airblast (non-reinforced conditioned stimulus, CS-). Fear was extinguished 10 min later through repeated presentations of the CSs without reinforcement. Number of clinically significant posttraumatic stress symptoms (PTSS) immediately following the mass shooting were positively associated with fear-potentiated startle (FPS) to the CS+ and CS- during late periods of acquisition. During early periods of fear extinction, PTSS was positively associated with FPS to the CS+. Results from the current study suggest that PTSS is related to altered fear inhibition and extinction during an FPS paradigm. In line with similar research, women with greater PTSS demonstrated a greater "fear load," suggesting that these women experienced elevated fear to the CS+ during extinction after conditioned fear was acquired.

  17. Gradients of Fear Potentiated Startle During Generalization, Extinction, and Extinction Recall--and Their Relations With Worry.

    PubMed

    Dunning, Jonathan P; Hajcak, Greg

    2015-09-01

    It is well established that fear conditioning plays a role in the development and maintenance of anxiety disorders. Moreover, abnormalities in fear generalization, extinction, and extinction recall have also been associated with anxiety. The present study used a generalization paradigm to examine fear processing during phases of generalization, extinction, and extinction recall. Specifically, participants were shocked following a CS+ and were also presented with stimuli that ranged in perceptual similarity to the CS+ (i.e., 20%, 40%, or 60% smaller or larger than the CS+) during a fear generalization phase. Participants were also presented with the same stimuli during an extinction phase and an extinction recall phase 1week later; no shocks were presented during extinction or recall. Lastly, participants completed self-report measures of worry and trait anxiety. Results indicated that fear potentiated startle (FPS) to the CS+ and GS±20% shapes was present in generalization and extinction, suggesting that fear generalization persisted into extinction. FPS to the CS+ was also evident 1 week later during extinction recall. Higher levels of worry were associated with greater FPS to the CS+ during generalization and extinction phases. Moreover, individuals high in worry had fear response gradients that were steeper during both generalization and extinction. This suggests that high levels of worry are associated with greater discriminative fear conditioning to threatening compared to safe stimuli and less fear generalization to perceptually similar stimuli.

  18. Nanoparticle Probes for Structural and Functional Photoacoustic Molecular Tomography

    PubMed Central

    Chen, Haobin; Yuan, Zhen; Wu, Changfeng

    2015-01-01

    Nowadays, nanoparticle probes have received extensive attention largely due to its potential biomedical applications in structural, functional, and molecular imaging. In addition, photoacoustic tomography (PAT), a method based on the photoacoustic effect, is widely recognized as a robust modality to evaluate the structure and function of biological tissues with high optical contrast and high acoustic resolution. The combination of PAT with nanoparticle probes holds promises for detecting and imaging diseased tissues or monitoring their treatments with high sensitivity. This review will introduce the recent advances in the emerging field of nanoparticle probes and their preclinical applications in PAT, as well as relevant perspectives on future development. PMID:26609534

  19. Measuring acoustic habitats.

    PubMed

    Merchant, Nathan D; Fristrup, Kurt M; Johnson, Mark P; Tyack, Peter L; Witt, Matthew J; Blondel, Philippe; Parks, Susan E

    2015-03-01

    1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies.

  20. Measuring acoustic habitats

    PubMed Central

    Merchant, Nathan D; Fristrup, Kurt M; Johnson, Mark P; Tyack, Peter L; Witt, Matthew J; Blondel, Philippe; Parks, Susan E

    2015-01-01

    1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies. PMID:25954500

  1. Hydrodynamic ultrasonic probe

    DOEpatents

    Day, Robert A.; Conti, Armond E.

    1980-01-01

    An improved probe for in-service ultrasonic inspection of long lengths of a workpiece, such as small diameter tubing from the interior. The improved probe utilizes a conventional transducer or transducers configured to inspect the tubing for flaws and/or wall thickness variations. The probe utilizes a hydraulic technique, in place of the conventional mechanical guides or bushings, which allows the probe to move rectilinearly or rotationally while preventing cocking thereof in the tube and provides damping vibration of the probe. The probe thus has lower friction and higher inspection speed than presently known probes.

  2. Probe tip heating assembly

    SciTech Connect

    Schmitz, Roger William; Oh, Yunje

    2016-10-25

    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably received and clamped within the socket.

  3. Acoustic emission monitoring system

    DOEpatents

    Romrell, Delwin M.

    1977-07-05

    Methods and apparatus for identifying the source location of acoustic emissions generated within an acoustically conductive medium. A plurality of acoustic receivers are communicably coupled to the surface of the medium at a corresponding number of spaced locations. The differences in the reception time of the respective sensors in response to a given acoustic event are measured among various sensor combinations prescribed by the monitoring mode employed. Acoustic reception response encountered subsequent to the reception by a predetermined number of the prescribed sensor combinations are inhibited from being communicated to the processing circuitry, while the time measurements obtained from the prescribed sensor combinations are translated into a position measurement representative of the location on the surface most proximate the source of the emission. The apparatus is programmable to function in six separate and five distinct operating modes employing either two, three or four sensory locations. In its preferred arrangement the apparatus of this invention will re-initiate a monitoring interval if the predetermined number of sensors do not respond to a particular emission within a given time period.

  4. ACOUSTICS IN ARCHITECTURAL DESIGN, AN ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS.

    ERIC Educational Resources Information Center

    DOELLE, LESLIE L.

    THE PURPOSE OF THIS ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS WAS--(1) TO COMPILE A CLASSIFIED BIBLIOGRAPHY, INCLUDING MOST OF THOSE PUBLICATIONS ON ARCHITECTURAL ACOUSTICS, PUBLISHED IN ENGLISH, FRENCH, AND GERMAN WHICH CAN SUPPLY A USEFUL AND UP-TO-DATE SOURCE OF INFORMATION FOR THOSE ENCOUNTERING ANY ARCHITECTURAL-ACOUSTIC DESIGN…

  5. Determination of hydrocarbon levels in water via laser-induced acoustics wave

    NASA Astrophysics Data System (ADS)

    Bidin, Noriah; Hossenian, Raheleh; Duralim, Maisarah; Krishnan, Ganesan; Marsin, Faridah Mohd; Nughro, Waskito; Zainal, Jasman

    2016-04-01

    Hydrocarbon contamination in water is a major environmental concern in terms of foreseen collapse of the natural ecosystem. Hydrocarbon level in water was determined by generating acoustic wave via an innovative laser-induced breakdown in conjunction with high-speed photographic coupling with piezoelectric transducer to trace acoustic wave propagation. A Q-switched Nd:YAG (40 mJ) was focused in cuvette-filled hydrocarbon solution at various concentrations (0-2000 ppm) to induce optical breakdown, shock wave generation and later acoustic wave propagation. A nitro-dye (ND) laser (10 mJ) was used as a flash to illuminate and frozen the acoustic wave propagation. Lasers were synchronised using a digital delay generator. The image of acoustic waves was grabbed and recorded via charged couple device (CCD) video camera at the speed of 30 frames/second with the aid of Matrox software version 9. The optical delay (0.8-10.0 μs) between the acoustic wave formation and its frozen time is recorded through photodetectors. A piezo-electric transducer (PZT) was used to trace the acoustic wave (sound signal), which cascades to a digital oscilloscope. The acoustic speed is calculated from the ratio of acoustic wave radius (1-8 mm) and optical time delay. Acoustic wave speed is found to linearly increase with hydrocarbon concentrations. The acoustic signal generation at higher hydrocarbon levels in water is attributed to supplementary mass transfer and impact on the probe. Integrated high-speed photography with transducer detection system authenticated that the signals indeed emerged from the laser-induced acoustic wave instead of photothermal processes. It is established that the acoustic wave speed in water is used as a fingerprint to detect the hydrocarbon levels.

  6. A New Wave of Acoustics.

    ERIC Educational Resources Information Center

    Beyer, Robert

    1981-01-01

    Surveys 50 years of acoustical studies by discussing selected topics including the ear, nonlinear representations, underwater sound, acoustical diagnostics, absorption, electrolytes, phonons, magnetic interaction, and superfluidity and the five sounds. (JN)

  7. Architectural-acoustics consulting

    NASA Astrophysics Data System (ADS)

    Hoover, Anthony K.

    2004-05-01

    Consulting involves both the science of acoustics and the art of communication, requiring an array of inherent and created skills. Perhaps because consulting on architectural acoustics is a relatively new field, there is a remarkable variety of career paths, all influenced by education, interest, and experience. Many consultants juggle dozens of chargeable projects at a time, not to mention proposals, seminars, teaching, articles, business concerns, and professional-society activities. This paper will discuss various aspects of career paths, projects, and clients as they relate to architectural-acoustics consulting. The intended emphasis will be considerations for those who may be interested in such a career, noting that consultants generally seem to thrive on the numerous challenges.

  8. High temperature acoustic levitator

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B. (Inventor)

    1984-01-01

    A system is described for acoustically levitating an object within a portion of a chamber that is heated to a high temperature, while a driver at the opposite end of the chamber is maintained at a relatively low temperature. The cold end of the chamber is constructed so it can be telescoped to vary the length (L sub 1) of the cold end portion and therefore of the entire chamber, so that the chamber remains resonant to a normal mode frequency, and so that the pressure at the hot end of the chamber is maximized. The precise length of the chamber at any given time, is maintained at an optimum resonant length by a feedback loop. The feedback loop includes an acoustic pressure sensor at the hot end of the chamber, which delivers its output to a control circuit which controls a motor that varies the length (L) of the chamber to a level where the sensed acoustic pressure is a maximum.

  9. Basic Linear Acoustics

    NASA Astrophysics Data System (ADS)

    Pierce, Alan

    This chapter deals with the physical and mathematical aspects of sound when the disturbances are, in some sense, small. Acoustics is usually concerned with small-amplitude phenomena, and consequently a linear description is usually applicable. Disturbances are governed by the properties of the medium in which they occur, and the governing equations are the equations of continuum mechanics, which apply equally to gases, liquids, and solids. These include the mass, momentum, and energy equations, as well as thermodynamic principles. The viscosity and thermal conduction enter into the versions of these equations that apply to fluids. Fluids of typical great interest are air and sea water, and consequently this chapter includes a summary of their relevant acoustic properties. The foundation is also laid for the consideration of acoustic waves in elastic solids, suspensions, bubbly liquids, and porous media.

  10. Acoustic Liners for Turbine Engines

    NASA Technical Reports Server (NTRS)

    Jones, Michael G (Inventor); Grady, Joseph E (Inventor); Kiser, James D. (Inventor); Miller, Christopher (Inventor); Heidmann, James D. (Inventor)

    2016-01-01

    An improved acoustic liner for turbine engines is disclosed. The acoustic liner may include a straight cell section including a plurality of cells with straight chambers. The acoustic liner may also include a bent cell section including one or more cells that are bent to extend chamber length without increasing the overall height of the acoustic liner by the entire chamber length. In some cases, holes are placed between cell chambers in addition to bending the cells, or instead of bending the cells.

  11. Spacecraft Internal Acoustic Environment Modeling

    NASA Technical Reports Server (NTRS)

    Allen, Christopher; Chu, S. Reynold

    2008-01-01

    The objective of the project is to develop an acoustic modeling capability, based on commercial off-the-shelf software, to be used as a tool for oversight of the future manned Constellation vehicles to ensure compliance with acoustic requirements and thus provide a safe and habitable acoustic environment for the crews, and to validate developed models via building physical mockups and conducting acoustic measurements.

  12. Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.

    2009-01-01

    Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

  13. International Congress on Acoustic Intensity Measurement: Measurement Techniques and Applications, 2nd, Senlis, France, September 23-26, 1985, Proceedings

    NASA Astrophysics Data System (ADS)

    Recent developments in acoustic-intensity measurement are discussed in reviews and reports of theoretical and experimental investigations. Instrumentation, vector acoustics, sound radiation, intensity in the presence of flow, intensity in structures, sound power, source localization, impedance, absorption, and transmission are the fields covered by the contributions. Specific topics addressed include microphone configurations for intensity probes, the rotational structure of intensity fields, acoustic intensity and numerical simulation, sound-power measurement in the presence of background noise, and techniques for measuring the absorption coefficient of acoustic materials. Graphs, drawings, diagrams, tables of numerical data, and photographs of test setups are provided.

  14. A preliminary study of acoustic propagation in thick foam tissue scaffolds composed of poly(lactic-co-glycolic acid)

    NASA Astrophysics Data System (ADS)

    Parker, N. G.; Mather, M. L.; Morgan, S. P.; Povey, M. J. W.

    2011-01-01

    The exclusive ability of acoustic waves to probe the structural, mechanical and fluidic properties of foams may offer novel approaches to characterise the porous scaffolds employed in tissue engineering. Motivated by this we conduct a preliminary investigation into the acoustic properties of a typical biopolymer and the feasibility of acoustic propagation within a foam scaffold thereof. Focussing on poly(lactic-co-glycolic acid), we use a pulse-echo method to determine the longitudinal speed of sound, whose temperature-dependence reveals the glass transition of the polymer. Finally, we demonstrate the first topographic and tomographic acoustic images of polymer foam tissue scaffolds.

  15. Tools to Compare Diving-Animal Kinematics with Acoustic Behavior and Exposure

    DTIC Science & Technology

    2010-09-30

    vehicle. Bioacoustic Probes have been employed as simple seafloor recorders in several studies, including a behavioral study of beluga - whale habitat usage...2005. Miniature self-contained acoustic recorders applied in a survey of beluga - whale populations in Knik Arm, Alaska (abstract). J. Acoust. Soc. Am...blue whales . Mar. Ecol-Prog. Ser. 330:269–284. [published, refereed] Tang, D. 2005. Inverting for sandy sediment sound speed in very shallow water

  16. Phase-sensitive imaging of tissue acoustic vibrations using spectrally encoded interferometry.

    PubMed

    Ilgayev, Ovadia; Yelin, Dvir

    2013-08-26

    Acoustic vibrations in tissue are often difficult to image, requiring high-speed scanning, high sensitivity and nanometer-scale axial resolution. Here we use spectrally encoded interferometry to measure the vibration pattern of two-dimensional surfaces, including the skin of a volunteer, at nanometric resolution, without the need for rapid lateral scanning and with no prior knowledge of the driving acoustic waveform. Our results demonstrate the feasibility of this technique for measuring tissue biomechanics using simple and compact imaging probes.

  17. Acoustic bubble removal method

    NASA Technical Reports Server (NTRS)

    Trinh, E. H.; Elleman, D. D.; Wang, T. G. (Inventor)

    1983-01-01

    A method is described for removing bubbles from a liquid bath such as a bath of molten glass to be used for optical elements. Larger bubbles are first removed by applying acoustic energy resonant to a bath dimension to drive the larger bubbles toward a pressure well where the bubbles can coalesce and then be more easily removed. Thereafter, submillimeter bubbles are removed by applying acoustic energy of frequencies resonant to the small bubbles to oscillate them and thereby stir liquid immediately about the bubbles to facilitate their breakup and absorption into the liquid.

  18. Broadband Acoustic Hyperbolic Metamaterial.

    PubMed

    Shen, Chen; Xie, Yangbo; Sui, Ni; Wang, Wenqi; Cummer, Steven A; Jing, Yun

    2015-12-18

    In this Letter, we report on the design and experimental characterization of a broadband acoustic hyperbolic metamaterial. The proposed metamaterial consists of multiple arrays of clamped thin plates facing the y direction and is shown to yield opposite signs of effective density in the x and y directions below a certain cutoff frequency, therefore, yielding a hyperbolic dispersion. Partial focusing and subwavelength imaging are experimentally demonstrated at frequencies between 1.0 and 2.5 kHz. The proposed metamaterial could open up new possibilities for acoustic wave manipulation and may find usage in medical imaging and nondestructive testing.

  19. Acoustic emission intrusion detector

    DOEpatents

    Carver, Donald W.; Whittaker, Jerry W.

    1980-01-01

    An intrusion detector is provided for detecting a forcible entry into a secured structure while minimizing false alarms. The detector uses a piezoelectric crystal transducer to sense acoustic emissions. The transducer output is amplified by a selectable gain amplifier to control the sensitivity. The rectified output of the amplifier is applied to a Schmitt trigger circuit having a preselected threshold level to provide amplitude discrimination. Timing circuitry is provided which is activated by successive pulses from the Schmitt trigger which lie within a selected time frame for frequency discrimination. Detected signals having proper amplitude and frequency trigger an alarm within the first complete cycle time of a detected acoustical disturbance signal.

  20. Electromechanical acoustic liner

    NASA Technical Reports Server (NTRS)

    Sheplak, Mark (Inventor); Cattafesta, III, Louis N. (Inventor); Nishida, Toshikazu (Inventor); Horowitz, Stephen Brian (Inventor)

    2007-01-01

    A multi-resonator-based system responsive to acoustic waves includes at least two resonators, each including a bottom plate, side walls secured to the bottom plate, and a top plate disposed on top of the side walls. The top plate includes an orifice so that a portion of an incident acoustical wave compresses gas in the resonators. The bottom plate or the side walls include at least one compliant portion. A reciprocal electromechanical transducer coupled to the compliant portion of each of the resonators forms a first and second transducer/compliant composite. An electrical network is disposed between the reciprocal electromechanical transducer of the first and second resonator.

  1. Broadband Acoustic Clutter

    DTIC Science & Technology

    2010-09-30

    fluidized mud, which has sound speeds at (or sometimes below) the sound speed of the water column, here 1512 m/s. Interestingly, there is a sound speed...data. 3 specular 25m Figure 1. The map shows the AUV track (red line) overlaid on multibeam bathymetry. Mean water depth is about 165m...Preston, and D.A. Abraham, Long-range acoustic scattering from a shallow- water mud volcano cluster J. Acoust. Soc. Am., 122, 1946-1958, 2007. [3

  2. Acoustic tooth cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S. (Inventor)

    1982-01-01

    An acoustic oral hygiene unit is described that uses acoustic energy to oscillate mild abrasive particles in a water suspension which is then directed in a low pressure stream onto the teeth. The oscillating abrasives scrub the teeth clean removing food particles, plaque, calculous, and other foreign material from tooth surfaces, interproximal areas, and tooth-gingiva interface more effectively than any previous technique. The relatively low power output and the basic design makes the invention safe and convenient for everyday use in the home without special training. This invention replaces all former means of home dental prophylaxis, and requires no augmentation to fulfill all requirements for daily oral hygienic care.

  3. Post Treatment of Acoustic Neuroma

    MedlinePlus

    Home What is an AN What is an Acoustic Neuroma? Identifying an AN Symptoms Acoustic Neuroma Keywords Educational Video Pre-Treatment Treatment Options Summary Treatment Options Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions ...

  4. Fundamentals of Acoustics. Psychoacoustics and Hearing. Acoustical Measurements

    NASA Technical Reports Server (NTRS)

    Begault, Durand R.; Ahumada, Al (Technical Monitor)

    1997-01-01

    These are 3 chapters that will appear in a book titled "Building Acoustical Design", edited by Charles Salter. They are designed to introduce the reader to fundamental concepts of acoustics, particularly as they relate to the built environment. "Fundamentals of Acoustics" reviews basic concepts of sound waveform frequency, pressure, and phase. "Psychoacoustics and Hearing" discusses the human interpretation sound pressure as loudness, particularly as a function of frequency. "Acoustic Measurements" gives a simple overview of the time and frequency weightings for sound pressure measurements that are used in acoustical work.

  5. Is dust acoustic wave a new plasma acoustic mode?

    NASA Astrophysics Data System (ADS)

    Dwivedi, C. B.

    1997-09-01

    In this Brief Communication, the claim of the novelty of the dust acoustic wave in a dusty plasma within the constant dust charge model is questioned. Conceptual lacunas behind the claim have been highlighted and appropriate physical arguments have been forwarded against the claim. It is demonstrated that the so-called dust acoustic wave could better be termed as a general acoustic fluctuation response with a dominant characteristic feature of the acoustic-like mode (ALM) fluctuation response reported by Dwivedi et al. [J. Plasma Phys. 41, 219 (1989)]. It is suggested that both correct and more usable nomenclature of the ALM should be the so-called acoustic mode.

  6. Acoustic subwavelength imaging of subsurface objects with acoustic resonant metalens

    SciTech Connect

    Cheng, Ying; Liu, XiaoJun; Zhou, Chen; Wei, Qi; Wu, DaJian

    2013-11-25

    Early research into acoustic metamaterials has shown the possibility of achieving subwavelength near-field acoustic imaging. However, a major restriction of acoustic metamaterials is that the imaging objects must be placed in close vicinity of the devices. Here, we present an approach for acoustic imaging of subsurface objects far below the diffraction limit. An acoustic metalens made of holey-structured metamaterials is used to magnify evanescent waves, which can rebuild an image at the central plane. Without changing the physical structure of the metalens, our proposed approach can image objects located at certain distances from the input surface, which provides subsurface signatures of the objects with subwavelength spatial resolution.

  7. Extract of Ginkgo biloba EGb761 facilitates extinction of conditioned fear measured by fear-potentiated startle.

    PubMed

    Yang, Yi-Ling; Su, Ya-Wen; Ng, Ming-Chong; Chao, Po-Kuan; Tung, Li-Chu; Lu, Kwok-Tung

    2007-02-01

    A standard extract of Ginkgo biloba (EGb761) has been used in the treatment of various common geriatric complaints including vertigo, short-term memory loss, hearing loss, lack of attention, or vigilance. We demonstrated that acute systemic administration of EGb761 facilitated the acquisition of conditioned fear. Many studies suggest the neural mechanism underlies extinction is similar to the acquisition. This raises a possibility that EGb761 may modulate and accelerate the fear extinction process. We tested this possibility by using fear-potentiated startle (FPS) on laboratory rats. Acute systemic injection of EGb761 (10, 20, or 50 mg/kg) 30 min before extinction training facilitated extinction in a dose-dependent manner. Intra-amygdaloid infusion of EGb761 (28 ng/side, bilaterally) 10 min before extinction training also facilitated extinction. Control experiments showed that facilitation effect of EGb761 was not the result of impaired expression of conditioned fear or accelerated forgetting. Rats previously injected with EGb761 showed significant FPS after retraining. Extinction of conditioned fear appeared to result from acute drug effects rather than from toxic action. Systemic administration of EGb761 immediately after extinction training did not facilitate extinction, suggested the EGb761 facilitation effect is contributed to the acquisition phase of extinction learning. Western blot results showed that extinction induced amygdaloid extracellular signal-regulated kinase (ERK1/2) phosphorylation was significantly elevated by EGb761 treatment. Intra-amygdala injection of ERK1/2 inhibitor PD98059 completely blocked the EGb761 effect. Therefore, acute EGb761 administration modulated extinction of conditioned fear by activating ERK1/2.

  8. Glutamate receptor antagonism in inferior colliculus attenuates elevated startle response of high anxiety diazepam-withdrawn rats.

    PubMed

    Cabral, A; De Ross, J; Castilho, V M; Brandão, M L; Nobre, M J

    2009-07-07

    Rats segregated according to low (LA) or high (HA) anxiety levels have been used as an important tool in the study of fear and anxiety. Since the efficacy of an anxiolytic compound is a function of the animal's basal anxiety level, it is possible that chronic treatment with a benzodiazepine (Bzp) affects LA and HA animals differently. Based on these assumptions, this study aimed to provide some additional information on the influence of acute, chronic (18 days) and withdrawal effects (48 h) from diazepam (10 mg/kg), in rats with LA or HA levels, on startle response amplitude. For this purpose, the elevated plus-maze (EPM) test was used. In addition, the role of glutamate receptors of the central nucleus of the inferior colliculus (cIC), the most important mesencephalic tectum integrative structure of the auditory pathways and a brain region that is linked to the processing of auditory information of aversive nature, was also evaluated. Our results showed that, contrary to the results obtained in LA rats, long-term treatment with diazepam promoted anxiolytic and aversive effects in HA animals that were tested under chronic effects or withdrawal from this drug, respectively. In addition, since Bzp withdrawal may function as an unconditioned stressor, the negative affective states observed in HA rats could be a by-product of GABA-glutamate imbalance in brain systems that modulate unconditioned fear and anxiety behaviors, since the blockade of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and N-methyl-D-aspartate (NMDA) glutamate receptors in the cIC clearly reduced the aversion promoted by diazepam withdrawal.

  9. Periadolescent ethanol vapor exposure produces reductions in hippocampal volume that are correlated with deficits in prepulse inhibition of the startle

    PubMed Central

    Ehlers, Cindy L.; Oguz, Ipek; Budin, Francois; Wills, Derek N.; Crews, Fulton T.

    2013-01-01

    BACKGROUND Epidemiological studies suggest that excessive alcohol consumption is prevalent among adolescents and may have lasting neurobehavioral consequences. The use of animal models allows for the separation of the effects of adolescent ethanol exposure from genetic background and other environmental insults. In the present study the effects of moderate ethanol vapor exposure, during adolescence, on structural diffusion tensor imaging (DTI) and behavioral measures were evaluated in adulthood. METHODS A total of 53 Wistar rats were received at postnatal day (PD) 21, and were randomly assigned to ethanol vapor (14 hrs on/10 hrs off/day) or air exposure for 35 days from PD 23-PD 58 (average blood ethanol concentration (BEC): 169 mg%). Animals were received in two groups that were subsequently sacrificed at two time points following withdrawal from ethanol vapor: (1) at 72 days of age, 2 weeks following withdrawal or (2) at day 128, 10 weeks following withdrawal. In the second group, behavior in the light/dark box and prepulse inhibition of the startle (PPI) were also evaluated. Fifteen animals in each group were scanned, post mortem, for structural DTI. RESULTS There were no significant differences in body weight between ethanol and control animals. Volumetric data, demonstrated that total brain, hippocampal, corpus callosum but not ventricular volume was significantly larger in the 128 day sacrificed animals as compared to the 72 day animals. The hippocampus was smaller and the ventricles larger at 128 days as compared to 72 days, in the ethanol exposed animals, leading to a significant group × time effect. Ethanol exposed animals sacrificed at 128 days also had diminished PPI and more rears in the light box that were significantly correlated with hippocampal size. CONCLUSIONS These studies demonstrate that DTI volumetric measures of hippocampus are significantly impacted by age and periadolescent ethanol exposure and withdrawal in Wistar rats. PMID:23578102

  10. Shipboard Acoustic Current Profiling during the Coastal Ocean Dynamics Experiment,

    DTIC Science & Technology

    1985-05-01

    Fig. 2.2 Range Gated Shipboard Doppler System . Four beams (fore. aft. port ard starboard) equally inclined from the ship’s vertical axis acousticallN...sarne cannot be said, however, for other beam geometries, such as the three-bean Jlanus system . M\\oreover. the effects, of finite beam width. side... System . Four beams (fore, aft, port and Sstarboard) equally inclined from the ship’s vertical axis acoustically probe the ocean. The Doppler shift in

  11. Application of guided acoustic waves to delamination detection

    NASA Technical Reports Server (NTRS)

    Sun, Keun J.

    1992-01-01

    Guided plate waves are able to interact with structural flaws such as delaminations and cracks due to their propagation properties highly sensitive to the thickness change in materials. A technique which employs an acoustic damper to probe the results of this interaction and then to locate flaws in a relatively short period of time is developed. With its technical advantages, this technique shows its potential application to large area structural integrity assessment.

  12. Frequency dependence of the acoustic field generated from a spherical cavity transducer with open ends

    SciTech Connect

    Li, Faqi; Zeng, Deping; He, Min; Wang, Zhibiao E-mail: wangzhibiao@haifu.com.cn; Song, Dan; Lei, Guangrong; Lin, Zhou; Zhang, Dong E-mail: wangzhibiao@haifu.com.cn; Wu, Junru

    2015-12-15

    Resolution of high intensity focused ultrasound (HIFU) focusing is limited by the wave diffraction. We have developed a spherical cavity transducer with two open ends to improve the focusing precision without sacrificing the acoustic intensity (App Phys Lett 2013; 102: 204102). This work aims to theoretically and experimentally investigate the frequency dependence of the acoustic field generated from the spherical cavity transducer with two open ends. The device emits high intensity ultrasound at the frequency ranging from 420 to 470 kHz, and the acoustic field is measured by a fiber optic probe hydrophone. The measured results shows that the spherical cavity transducer provides high acoustic intensity for HIFU treatment only in its resonant modes, and a series of resonant frequencies can be choosen. Furthermore, a finite element model is developed to discuss the frequency dependence of the acoustic field. The numerical simulations coincide well with the measured results.

  13. Invention of a tunable damper for use with an acoustic waveguide in hostile environments

    SciTech Connect

    Rogers, S.C.

    1984-06-01

    A damper was invented to remove undesirable stress pulses from an acoustic waveguide. Designed to be tunable, the damper was constructed to withstand a corrosive or otherwise hostile environment. It serves to simplify the design and enhance the performance of a water-level measurement system, of which the damper and acoustic waveguide are integral parts. An experimental damper was constructed and applied to an existing level probe and measurement system. The resulting damper, properly tuned, causes acoustic stress pulses that pass into it along the waveguide to be attenuated.

  14. Acoustics- Version 1.0

    SciTech Connect

    2012-09-13

    This package contains modules that model acoustic sensors and acoustic sources (hearable) in Umbra. It is typically used to represent hearing in characters within Umbra. Typically, the acoustic sensors detect acoustic sources at a given point; however, it also contains the capability to detect bullet cracks by detecting the sound along the bullet path that is closest to the sensor. A memory module, acoustic memory, represents remembered sounds within a given character. Over time, the sounds are removed, as a character forgets what it has heard.

  15. Acoustic visualizations using surface mapping.

    PubMed

    Siltanen, Samuel; Robinson, Philip W; Saarelma, Jukka; Pätynen, Jukka; Tervo, Sakari; Savioja, Lauri; Lokki, Tapio

    2014-06-01

    Sound visualizations have been an integral part of room acoustics studies for more than a century. As acoustic measurement techniques and knowledge of hearing evolve, acousticians need more intuitive ways to represent increasingly complex data. Microphone array processing now allows accurate measurement of spatio-temporal acoustic properties. However, the multidimensional data can be a challenge to display coherently. This letter details a method of mapping visual representations of acoustic reflections from a receiver position to the surfaces from which the reflections originated. The resulting animations are presented as a spatial acoustic analysis tool.

  16. Intelligent Engine Systems: Acoustics

    NASA Technical Reports Server (NTRS)

    Wojno, John; Martens, Steve; Simpson, Benjamin

    2008-01-01

    An extensive study of new fan exhaust nozzle technologies was performed. Three new uniform chevron nozzles were designed, based on extensive CFD analysis. Two new azimuthally varying variants were defined. All five were tested, along with two existing nozzles, on a representative model-scale, medium BPR exhaust nozzle. Substantial acoustic benefits were obtained from the uniform chevron nozzle designs, the best benefit being provided by an existing design. However, one of the azimuthally varying nozzle designs exhibited even better performance than any of the uniform chevron nozzles. In addition to the fan chevron nozzles, a new technology was demonstrated, using devices that enhance mixing when applied to an exhaust nozzle. The acoustic benefits from these devices applied to medium BPR nozzles were similar, and in some cases superior to, those obtained from conventional uniform chevron nozzles. However, none of the low noise technologies provided equivalent acoustic benefits on a model-scale high BPR exhaust nozzle, similar to current large commercial applications. New technologies must be identified to improve the acoustics of state-of-the-art high BPR jet engines.

  17. Concert hall acoustics

    NASA Astrophysics Data System (ADS)

    Schroeder, Manfred

    2004-05-01

    I will review some work at Bell Laboratories on artificial reverberation and concert hall acoustics including Philharmonic Hall (Lincoln Center for the Performing Arts, New York). I will also touch on sound diffusion by number-theoretic surfaces and the measurement of reverberation time using the music as played in the hall as a ``test'' signal.

  18. Acoustics in Schools.

    ERIC Educational Resources Information Center

    Singer, Miriam J.

    This paper explores the issues associated with poor acoustics within schools. Additionally, it suggests remedies for existing buildings and those under renovation, as well as concerns for new construction. The paper discusses the effects of unwanted noise on students in terms of physiological, motivational, and cognitive influences. Issues are…

  19. Micro acoustic spectrum analyzer

    DOEpatents

    Schubert, W. Kent; Butler, Michael A.; Adkins, Douglas R.; Anderson, Larry F.

    2004-11-23

    A micro acoustic spectrum analyzer for determining the frequency components of a fluctuating sound signal comprises a microphone to pick up the fluctuating sound signal and produce an alternating current electrical signal; at least one microfabricated resonator, each resonator having a different resonant frequency, that vibrate in response to the alternating current electrical signal; and at least one detector to detect the vibration of the microfabricated resonators. The micro acoustic spectrum analyzer can further comprise a mixer to mix a reference signal with the alternating current electrical signal from the microphone to shift the frequency spectrum to a frequency range that is a better matched to the resonant frequencies of the microfabricated resonators. The micro acoustic spectrum analyzer can be designed specifically for portability, size, cost, accuracy, speed, power requirements, and use in a harsh environment. The micro acoustic spectrum analyzer is particularly suited for applications where size, accessibility, and power requirements are limited, such as the monitoring of industrial equipment and processes, detection of security intrusions, or evaluation of military threats.

  20. Detecting Contaminant Particles Acoustically

    NASA Technical Reports Server (NTRS)

    Wyett, L. M.

    1986-01-01

    Apparatus "listens" for particles in interior of complex turbomachinery. Contact microphones are attached at several points on pump housing. Acoustic transducer also attached to housing to excite entire pump with sound. Frequency of sound is slowly raised until pump resonates. Microphones detect noise of loose particles scraping against pump parts. Such as machining chips in turbopumps or other machinery without disassembly.