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Sample records for acoustic startle stimuli

  1. 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.

  2. 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.

  3. 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

  4. 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. PMID:27547181

  5. Cocaine: effects on acoustic startle and startle elicited electrically from the cochlear nucleus.

    PubMed

    Harty, T P; Davis, M

    1985-01-01

    Startle-like responses can be elicited by single pulse electrical stimulation of nuclei within the acoustic startle pathway. Compared with acoustically-elicited startle, this technique provides a method for localizing the ultimate sites of action of a drug that affects the acoustic startle response. Strychnine (1 mg/kg) increased both acoustically-elicited startle and startle elicited from the ventral cochlear nucleus (VCN), the first central nucleus in the acoustic startle pathway. In contrast, cocaine (10 mg/kg) increased acoustically-elicited startle but depressed VCN-elicited startle. These results suggest that cocaine increases startle by acting on sensory rather than final motor systems and are discussed in relation to the putative effect of cocaine on dopamine neurotransmission and the involvement of dopamine in sensorimotor reactivity. PMID:3001807

  6. 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…

  7. 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.

  8. 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

  9. Effects of selected anticholinergics on acoustic startle response in rats.

    PubMed

    Sipos, M L; Burchnell, V; Galbicka, G

    2001-12-01

    The present study compared the effects of the anticholinergics aprophen hydrochloride, atropine sulfate, azaprophen hydrochloride, benactyzine hydrochloride, biperiden hydrochloride, diazepam, procyclidine hydrochloride, scopolamine hydrobromide and trihexyphenidyl hydrochloride on acoustic startle response in rats. Peak startle amplitude, latency to peak startle amplitude and prepulse inhibition following 100- and 120-dB tones were recorded 15 min following drug administration in food-restricted rats. Aprophen, atropine, azaprophen, benactyzine, biperiden and scopolamine significantly increased peak startle amplitude and decreased latency to peak startle amplitude following 100-dB pulses. In contrast, only biperiden increased peak startle amplitude following 120-dB pulses, whereas atropine and trihexyphenidyl decreased latency to peak startle amplitude following 120-dB pulses. Benactyzine decreased prepulse inhibition following both 100- and 120-dB pulses, whereas both biperiden and scopolamine decreased prepulse inhibition following 120-dB pulses. Acoustic startle response measures were effective in differentiating the effects of anticholinergic compounds. The comparison of drug effects on the acoustic startle response may be useful in selecting efficacious anticholinergic drug therapies with a minimal range of side-effects. In addition, these data may be useful in down-selecting the number of anticholinergic drugs that need to be tested in comparison studies involving more complex behavioral tests. PMID:11920928

  10. Lipopolysaccharide does not affect acoustic startle reflex in mice.

    PubMed

    Juszczak, Grzegorz R; Blaszczyk, Janusz; Sadowski, Bogdan; Sliwa, Adam T; Wolak, Patrycja; Tymosiak-Zielinska, Agnieszka; Lisowski, Pawel; Swiergiel, Artur H

    2008-01-01

    Bacterial endotoxin (lipopolysaccharide; LPS) evokes in rodents an adaptive sickness behavior. It also produces changes in stress hormones secretion and activity of brain serotonergic and noradrenergic systems that have been implicated in stress responses, fear, and anxiety. Acoustic startle reflex (ASR) is regarded as a protective behavioral response that is enhanced in threatening situations or following an aversive event, and it can be modulated by physiological and emotional state of an animal. Effects of intraperitoneal injections of LPS on ASR, prepulse inhibition (PPI), locomotor activity in open field, and blood plasma corticosterone concentration were studied in lines of mice that display high (HA line) or low (LA line) swim stress-induced analgesia and also differ in emotional behaviors, including the magnitude of ASR. In both lines LPS produced robust sickness behavior, as evidenced by a decrease in locomotion and body weight, and an increase in corticosterone concentration. However, in neither line LPS injections affected responses to acoustic stimuli as assessed by the ASR and PPI magnitudes. The findings suggest that in sickness behavior induced by LPS the protective responses to salient environmental stimuli are not impaired. The significance of this finding for the concept of sickness behavior is discussed. PMID:17651939

  11. 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

  12. 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.

  13. 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…

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

    PubMed

    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.

  15. 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

  16. Repeated elicitation of the acoustic startle reflex leads to sensitisation in subsequent avoidance behaviour and induces fear conditioning

    PubMed Central

    2011-01-01

    Background Autonomous reflexes enable animals to respond quickly to potential threats, prevent injury and mediate fight or flight responses. Intense acoustic stimuli with sudden onsets elicit a startle reflex while stimuli of similar intensity but with longer rise times only cause a cardiac defence response. In laboratory settings, habituation appears to affect all of these reflexes so that the response amplitude generally decreases with repeated exposure to the stimulus. The startle reflex has become a model system for the study of the neural basis of simple learning processes and emotional processing and is often used as a diagnostic tool in medical applications. However, previous studies did not allow animals to avoid the stimulus and the evolutionary function and long-term behavioural consequences of repeated startling remain speculative. In this study we investigate the follow-up behaviour associated with the startle reflex in wild-captured animals using an experimental setup that allows individuals to exhibit avoidance behaviour. Results We present evidence that repeated elicitation of the acoustic startle reflex leads to rapid and pronounced sensitisation of sustained spatial avoidance behaviour in grey seals (Halichoerus grypus). Animals developed rapid flight responses, left the exposure pool and showed clear signs of fear conditioning. Once sensitised, seals even avoided a known food source that was close to the sound source. In contrast, animals exposed to non-startling (long rise time) stimuli of the same maximum sound pressure habituated and flight responses waned or were absent from the beginning. The startle threshold of grey seals expressed in units of sensation levels was comparable to thresholds reported for other mammals (93 dB). Conclusions Our results demonstrate that the acoustic startle reflex plays a crucial role in mediating flight responses and strongly influences the motivational state of an animal beyond a short-term muscular response by

  17. 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. PMID:20814814

  18. Increased sensitization of acoustic startle response in spasmodic mice with a mutation of the glycine receptor alpha1-subunit gene.

    PubMed

    Plappert, C F; Pilz, P K; Becker, K; Becker, C M; Schnitzler, H U

    2001-06-01

    The spontaneous mutant mouse spasmodic (spd) carries a missense mutation affecting the glycine receptor alpha1-subunit gene. This results in a decreased binding affinity to glycine. Spd mutants show exaggerated acoustic startle responses (ASR). The present study sought to elucidate whether this increased ASR is due to a changed auditory processing or to stronger motor output resulting from a disinhibited motor system or, alternatively, to changes in modulatory influences on the startle pathway, namely in the mechanisms underlying habituation and sensitization. We found that in homozygous spd/spd mutants the startle threshold was lower, and the recorded slope of input/output (i/o) function, which reflects the relation between sensory input and motor output, was steeper. During repetitive presentation of high sound pressure level (SPL) startle stimuli (25 dB above startle threshold), ASR amplitudes did not decrease in spd/spd mutants as they do in the wildtype. In contrast, ASR amplitudes decreased when low SPL startle stimuli were presented. Footshocks presented after high SPL startle stimuli did not cause a further increase in ASR amplitudes of spd/spd mutants as in the wildtype. In heterozygous spd/+ mutants all these parameters were between those of spd/spd mutants and wildtype mice but closer to those of the wildtype. The steeper slope of i/o function in spd/spd mutants may be caused by both an increased sensory input and an increased motor output. The altered course of ASR amplitudes during repetitive stimulation and the deficit in additional footshock sensitization, however, can only be explained by an increased sensitization level in the spd/spd mutants. In accordance with the "dual process theory" strong sensitization evoked by high SPL startle stimuli supposedly counteracts habituation, leading to a constant high ASR amplitude. Furthermore, additional footshock sensitization is prevented. The increased sensitization level may be due to a change in auditory

  19. 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…

  20. Combined prenatal and chronic postnatal vitamin D deficiency in rats impairs prepulse inhibition of acoustic startle.

    PubMed

    Burne, Thomas H J; Féron, François; Brown, Jillanne; Eyles, Darryl W; McGrath, John J; Mackay-Sim, Alan

    2004-06-01

    There is growing evidence that 1,25-dihydroxyvitamin D3 is involved in normal brain development. The aim of this study was to examine the impact of prenatal and postnatal hypovitaminosis D on prepulse inhibition (PPI) of acoustic startle in adult rats. We compared six groups of rats: control rats with normal vitamin D throughout life and normal litter size (Litter); control rats with normal vitamin D but with a reduced litter size of two (Control); offspring from reduced litters of vitamin D deplete mothers who were repleted at birth (Birth), repleted at weaning (Weaning) or remained on a deplete diet until 10 weeks of age (Life); or control rats that were placed on a vitamin D-deficient diet from 5 to 10 weeks of age (Adult). All rats were tested in acoustic startle chambers at 5 and 10 weeks of age for acoustic startle responses and for PPI. There were no significant group differences at 5 weeks of age on the acoustic startle response or on PPI. At 10 weeks of age, rats in the Life group only had impaired PPI despite having normal acoustic startle responses. We conclude that combined prenatal and chronic postnatal hypovitaminosis D, but not early life hypovitaminosis D, alters PPI. PMID:15178159

  1. 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

  2. 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.

  3. Habituation of the acoustic and the tactile startle responses in mice: two independent sensory processes.

    PubMed

    Pilz, Peter K D; Carl, Thomas D; Plappert, Claudia F

    2004-10-01

    To test whether habituation is specific to the stimulus modality, the authors analyzed cross-habituation between the tactile startle response' (TSR) and the acoustic startle response (ASR). The acoustic artifacts of airpuffs used to elicit the TSR were reduced by using a silencer and were effectively masked by background noise of 90-100 dB sound-pressure level. ASR was elicited by 14-kHz tones. TSR and ASR habituated in DBA and BALB mice: both the TSR and ASR habituated to a greater extent in DBA mice than in BALB mice. In both strains, habituation of the TSR did not generalize to the ASR, and vice versa. From this, the authors concluded that habituation of startle is located in the sensory afferent branches of the pathway.

  4. 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 with…

  5. Dependence of the Startle Response on Temporal and Spectral Characteristics of Acoustic Modulatory Influences in Rats and Gerbils

    PubMed Central

    Steube, Natalie; Nowotny, Manuela; Pilz, Peter K. D.; Gaese, Bernhard H.

    2016-01-01

    The acoustic startle response (ASR) and its modulation by non-startling prepulses, presented shortly before the startle-eliciting stimulus, is a broadly applied test paradigm to determine changes in neural processing related to auditory or psychiatric disorders. Modulation by a gap in background noise as a prepulse is especially used for tinnitus assessment. However, the timing and frequency-related aspects of prepulses are not fully understood. The present study aims to investigate temporal and spectral characteristics of acoustic stimuli that modulate the ASR in rats and gerbils. For noise-burst prepulses, inhibition was frequency-independent in gerbils in the test range between 4 and 18 kHz. Prepulse inhibition (PPI) by noise-bursts in rats was constant in a comparable range (8–22 kHz), but lower outside this range. Purely temporal aspects of prepulse–startle-interactions were investigated for gap-prepulses focusing mainly on gap duration. While very short gaps had no (rats) or slightly facilitatory (gerbils) influence on the ASR, longer gaps always had a strong inhibitory effect. Inhibition increased with durations up to 75 ms and remained at a high level of inhibition for durations up to 1000 ms for both, rats and gerbils. Determining spectral influences on gap-prepulse inhibition (gap-PPI) revealed that gerbils were unaffected in the limited frequency range tested (4–18 kHz). The more detailed analysis in rats revealed a variety of frequency-dependent effects. Gaps in pure-tone background elicited constant and high inhibition (around 75%) over a broad frequency range (4–32 kHz). For gaps in noise-bands, on the other hand, a clear frequency-dependency was found: inhibition was around 50% at lower frequencies (6–14 kHz) and around 70% at high frequencies (16–20 kHz). This pattern of frequency-dependency in rats was specifically resulting from the inhibitory effect by the gaps, as revealed by detailed analysis of the underlying startle amplitudes. An

  6. 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

  7. 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. PMID:27445773

  8. 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

  9. 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.

  10. 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. PMID:26829110

  11. 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

  12. 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. PMID:22522185

  13. Gamma butyrolactone (GBL) and gamma valerolactone (GVL): similarities and differences in their effects on the acoustic startle reflex and the conditioned enhancement of startle in the rat.

    PubMed

    Marinetti, Laureen J; Leavell, Bonita J; Jones, Calleen M; Hepler, Bradford R; Isenschmid, Daniel S; Commissaris, Randall L

    2012-06-01

    Gamma butyrolactone (GBL) is metabolized to gamma hydroxybutyrate (GHB) in the body. GHB is a DEA Schedule 1 compound; GBL is a DEA List 1 chemical. Gamma valerolactone (GVL) is the 4-methyl analog of GBL; GVL is metabolized to 4-methyl-GHB; GVL is NOT metabolized to GBL or GHB. The effects of GBL (18.75-150 mg/kg), GVL (200-1600 mg/kg) or vehicle on the acoustic startle reflex (ASR), and the classically-conditioned enhancement of startle, the Startle Anticipated Potentiation of Startle (SAPS) response were studied in male rats. Both compounds produced a dose-dependent reduction of ASR, with GBL 5-7 times more potent than GVL. In contrast, GBL treatment significantly reduced SAPS at doses that exerted only moderate effects on ASR, whereas GVL exerted little or no effect on the SAPS, except at doses that produced pronounced reductions in Noise Alone ASR. In a second experiment, rats were tested for Noise Alone ASR behavior following treatment with a single mid-range dose of GBL (75 mg/kg), GVL (400mg/kg) or vehicle; immediately following startle testing the animals were sacrificed and their brains and blood were collected for determination of GHB, 4-methyl-GHB, GBL and GVL. GHB was found in measurable concentrations in all of the blood specimens and 6 (of 8) of the brain specimens from the GBL-treated subjects. 4-Methyl-GHB was found in measurable concentrations in all of the blood and brain specimens of the GVL-treated subjects; the change in startle amplitude was inversely correlated to the brain concentrations of these compounds. These findings confirm the differences in the metabolic fate of GBL and GVL as pro-drugs for the formation of GHB and 4-methyl-GHB, respectively. Moreover, the dissimilarity in effect profile for GBL and GVL on ASR versus SAPS behaviors suggests that different receptor(s) may be involved in mediating these behavioral effects. PMID:22349589

  14. Methodological optimization of tinnitus assessment using prepulse inhibition of the acoustic startle reflex.

    PubMed

    Longenecker, R J; Galazyuk, A V

    2012-11-16

    Recently prepulse inhibition of the acoustic startle reflex (ASR) became a popular technique for tinnitus assessment in laboratory animals. This method confers a significant advantage over the previously used time-consuming behavioral approaches utilizing basic mechanisms of conditioning. Although this technique has been successfully used to assess tinnitus in different laboratory animals, many of the finer details of this methodology have not been described enough to be replicated, but are critical for tinnitus assessment. Here we provide detail description of key procedures and methodological issues that provide guidance for newcomers with the process of learning to correctly apply gap detection techniques for tinnitus assessment in laboratory animals. The major categories of these issues include: refinement of hardware for best performance, optimization of stimulus parameters, behavioral considerations, and identification of optimal strategies for data analysis. This article is part of a Special Issue entitled: Tinnitus Neuroscience.

  15. Toxoplasma gondii exposure affects neural processing speed as measured by acoustic startle latency in schizophrenia and controls.

    PubMed

    Pearce, Bradley D; Hubbard, Sydney; Rivera, Hilda N; Wilkins, Patricia P; Fisch, Marylynn C; Hopkins, Myfanwy H; Hasenkamp, Wendy; Gross, Robin; Bliwise, Nancy; Jones, Jeffrey L; Duncan, Erica

    2013-10-01

    The prevalence of Toxoplasma gondii (TOXO) infection in schizophrenia (SCZ) is elevated compared to controls (odds ratio=2.73). TOXO infection is associated with psychomotor slowing in rodents and non-psychiatric humans. Latency of the acoustic startle response, an index of neural processing speed, is the time it takes for a startling stimulus to elicit the reflexive response through a three-synapse subcortical circuit. We report a significant slowing of latency in TOXO seropositive SCZ vs. seronegative SCZ, and in TOXO seropositive controls vs. seronegative controls. Latency was likewise slower in SCZ subjects than in controls. These findings indicate a slowing of neural processing speed with chronic TOXO infection; the slowest startle latency was seen in the TOXO seropositive SCZ group.

  16. Prepulse inhibition of the acoustic startle reflex vs. auditory brainstem response for hearing assessment.

    PubMed

    Longenecker, R J; Alghamdi, F; Rosen, M J; Galazyuk, A V

    2016-09-01

    The high prevalence of noise-induced and age-related hearing loss in the general population has warranted the use of animal models to study the etiology of these pathologies. Quick and accurate auditory threshold determination is a prerequisite for experimental manipulations targeting hearing loss in animal models. The standard auditory brainstem response (ABR) measurement is fairly quick and translational across species, but is limited by the need for anesthesia and a lack of perceptual assessment. The goal of this study was to develop a new method of hearing assessment utilizing prepulse inhibition (PPI) of the acoustic startle reflex, a commonly used tool that measures detection thresholds in awake animals, and can be performed on multiple animals simultaneously. We found that in control mice PPI audiometric functions are similar to both ABR and traditional operant conditioning audiograms. The hearing thresholds assessed with PPI audiometry in sound exposed mice were also similar to those detected by ABR thresholds one day after exposure. However, three months after exposure PPI threshold shifts were still evident at and near the frequency of exposure whereas ABR thresholds recovered to the pre-exposed level. In contrast, PPI audiometry and ABR wave one amplitudes detected similar losses. PPI audiometry provides a high throughput automated behavioral screening tool of hearing in awake animals. Overall, PPI audiometry and ABR assessments of the auditory system are robust techniques with distinct advantages and limitations, which when combined, can provide ample information about the functionality of the auditory system. PMID:27349914

  17. [Early social isolation increases aggression and impairs a short-term habituation in acoustic startle reflex in rats].

    PubMed

    Krupina, N A; Khlebnikova, N N; Orlova, I N

    2015-01-01

    Prolonged social isolation in early ontogeny leads to various changes in behavior and cognitive dysfunction in adult rats; however, data on the disorders are contradictory. In the present work, we studied the effects of early social isolation in Wistar rats by indices of psychomotor activity, aggression, anxiety, depression-like behavior, sensorimotor reactivity and short-term habituation of acoustic startle reflex. On the 24th postnatal day, rats were weaned from the dams and housed in individual cages for nine consecutive weeks. Animal behavior was evaluated at the age of one, two and three months. Immediately after weaning from the dam rats in the experimental group did not differ from the control on any of the indices. After four weeks of social isolation, rats showed an increased aggression in the social contact test. In rats isolated for an 8-weeks period, the increase in active non-aggressive contacts with a slight increase in motor activity in the elevated plus maze (E PM) accompanied increased aggression. At any terms of examination, isolated rats did not differ from the control in the anxiety in EPM, in the anxiety-phobic score, which is evaluated in a battery of tests, and in the duration of immobility which characterizes depression in the forced swimming test. Rats isolated for an 8-weeks period increased daily liquid intake by increasing the consumption of sucrose. After nine weeks of isolation, basal startle amplitude and prepulse inhibition that is, the characteristics of sensorimotor gating did not differ from the control, but there was a lack of short-term habituation of the acoustic startle reflex. Based on the data obtained, Wistar rats subjected to prolonged social isolation can be seen as a model of increased aggression with signs of cognitive deficits by indices of non-associative learning in the acoustic startle reflex.

  18. [Early social isolation increases aggression and impairs a short-term habituation in acoustic startle reflex in rats].

    PubMed

    Krupina, N A; Khlebnikova, N N; Orlova, I N

    2015-01-01

    Prolonged social isolation in early ontogeny leads to various changes in behavior and cognitive dysfunction in adult rats; however, data on the disorders are contradictory. In the present work, we studied the effects of early social isolation in Wistar rats by indices of psychomotor activity, aggression, anxiety, depression-like behavior, sensorimotor reactivity and short-term habituation of acoustic startle reflex. On the 24th postnatal day, rats were weaned from the dams and housed in individual cages for nine consecutive weeks. Animal behavior was evaluated at the age of one, two and three months. Immediately after weaning from the dam rats in the experimental group did not differ from the control on any of the indices. After four weeks of social isolation, rats showed an increased aggression in the social contact test. In rats isolated for an 8-weeks period, the increase in active non-aggressive contacts with a slight increase in motor activity in the elevated plus maze (E PM) accompanied increased aggression. At any terms of examination, isolated rats did not differ from the control in the anxiety in EPM, in the anxiety-phobic score, which is evaluated in a battery of tests, and in the duration of immobility which characterizes depression in the forced swimming test. Rats isolated for an 8-weeks period increased daily liquid intake by increasing the consumption of sucrose. After nine weeks of isolation, basal startle amplitude and prepulse inhibition that is, the characteristics of sensorimotor gating did not differ from the control, but there was a lack of short-term habituation of the acoustic startle reflex. Based on the data obtained, Wistar rats subjected to prolonged social isolation can be seen as a model of increased aggression with signs of cognitive deficits by indices of non-associative learning in the acoustic startle reflex. PMID:27116871

  19. 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

  20. Chords and harmonies in mixed optical and acoustical stimuli

    NASA Astrophysics Data System (ADS)

    Hahlweg, Cornelius; Dannenberg, Florian; Dörfler, Joachim; Weber, Bernhard; Weyer, Cornelia; Gercke-Hahn, Harald; Freimuth, Steffen; Heucke, Sören; Gutzmann, Holger Ludwig

    2014-09-01

    The paper is a follow up of the work presented in last year's Optics and Music session on the perception of coherence between low frequency power modulated light and periodical acoustic stimuli. The composition of chords and harmonies from power modulated light sources and their effect as stand-alone stimulus and in conjunction with the equivalent acoustic signal is discussed. Of special interest here is the modulation near perceptible flicker frequency. The substitution of acoustical chord components by their optical counterpart and vice versa is investigated. Further, concepts of a training application for trombone players and other instrumentalists are presented: since the mean slide of the trombone does not have fixed positions, the note must be found and two players might influence each other. The possibility of helping them to synchronize by optical stimuli derived from their playing is investigated. Beside possible applications in emotional reinforcing multimedia oriented entertainment and training support for musicians, again implications for occupational medicine are discussed.

  1. 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…

  2. 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.

  3. 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.

  4. Evidence for a response preparation bottleneck during dual-task performance: effect of a startling acoustic stimulus on the psychological refractory period.

    PubMed

    Maslovat, Dana; Chua, Romeo; Spencer, Hunter C; Forgaard, Christopher J; Carlsen, Anthony N; Franks, Ian M

    2013-11-01

    The present study was designed to investigate the mechanism associated with dual-task interference in a psychological refractory period (PRP) paradigm. We used a simple reaction time paradigm consisting of a vocal response (R1) and key-lift task (R2) with a stimulus onset asynchrony (SOA) between 100ms and 1500ms. On selected trials we implemented a startling acoustic stimulus concurrent with the second stimulus to determine if we could involuntarily trigger the second response. Our results indicated that the PRP delay in the second response was present for both control and startle trials at short SOAs, suggesting the second response was not prepared in advance. These results support a response preparation bottleneck and can be explained via a neural activation model of preparation. In addition, we found that the reflexive startle activation was reduced in the dual-task condition for all SOAs, a result we attribute to prepulse inhibition associated with dual-task processing.

  5. Hemispheric specialization in dogs for processing different acoustic stimuli.

    PubMed

    Siniscalchi, Marcello; Quaranta, Angelo; Rogers, Lesley J

    2008-01-01

    Considerable experimental evidence shows that functional cerebral asymmetries are widespread in animals. Activity of the right cerebral hemisphere has been associated with responses to novel stimuli and the expression of intense emotions, such as aggression, escape behaviour and fear. The left hemisphere uses learned patterns and responds to familiar stimuli. Although such lateralization has been studied mainly for visual responses, there is evidence in primates that auditory perception is lateralized and that vocal communication depends on differential processing by the hemispheres. The aim of the present work was to investigate whether dogs use different hemispheres to process different acoustic stimuli by presenting them with playbacks of a thunderstorm and their species-typical vocalizations. The results revealed that dogs usually process their species-typical vocalizations using the left hemisphere and the thunderstorm sounds using the right hemisphere. Nevertheless, conspecific vocalizations are not always processed by the left hemisphere, since the right hemisphere is used for processing vocalizations when they elicit intense emotion, including fear. These findings suggest that the specialisation of the left hemisphere for intraspecific communication is more ancient that previously thought, and so is specialisation of the right hemisphere for intense emotions. PMID:18843371

  6. Hemispheric specialization in dogs for processing different acoustic stimuli.

    PubMed

    Siniscalchi, Marcello; Quaranta, Angelo; Rogers, Lesley J

    2008-01-01

    Considerable experimental evidence shows that functional cerebral asymmetries are widespread in animals. Activity of the right cerebral hemisphere has been associated with responses to novel stimuli and the expression of intense emotions, such as aggression, escape behaviour and fear. The left hemisphere uses learned patterns and responds to familiar stimuli. Although such lateralization has been studied mainly for visual responses, there is evidence in primates that auditory perception is lateralized and that vocal communication depends on differential processing by the hemispheres. The aim of the present work was to investigate whether dogs use different hemispheres to process different acoustic stimuli by presenting them with playbacks of a thunderstorm and their species-typical vocalizations. The results revealed that dogs usually process their species-typical vocalizations using the left hemisphere and the thunderstorm sounds using the right hemisphere. Nevertheless, conspecific vocalizations are not always processed by the left hemisphere, since the right hemisphere is used for processing vocalizations when they elicit intense emotion, including fear. These findings suggest that the specialisation of the left hemisphere for intraspecific communication is more ancient that previously thought, and so is specialisation of the right hemisphere for intense emotions.

  7. An improved approach to separating startle data from noise

    PubMed Central

    Grimsley, Calum A; Longenecker, Ryan J; Rosen, Merri J; Young, Jesse W; Grimsley, Jasmine M; Galazyuk, Alexander V

    2015-01-01

    Background The acoustic startle reflex (ASR) is a rapid, involuntary movement to sound, found in many species. The ASR can be modulated by external stimuli and internal state, making it a useful tool in many disciplines. ASR data collection and interpretation varies greatly across laboratories making comparisons a challenge New method Here we investigate the animal movement associated with a startle in mouse (CBA/CaJ). Movements were simultaneously captured with high-speed video and a piezoelectric startle plate. We also use simple mathematical extrapolations to convert startle data (force) into center of mass displacement (“height”), which incorporates the animal’s mass. Results Startle plate force data revealed a stereotype waveform associated with a startle that contained three distinct peaks. This waveform allowed researchers to separate trials into ‘startles’ and ‘no-startles’ (termed ‘manual classification). Fleiss’ kappa and Krippendorff’s alpha (0.865 for both) indicate very good levels of agreement between researchers. Further work uses this waveform to develop an automated startle classifier. The automated classifier compares favorably with manual classification. A two-way ANOVA reveals no significant difference in the magnitude of the 3 peaks as classified by the manual and automated methods (P1: p=0.526, N1: p=0.488, P2: p=0.529). Comparison with existing method(s) The ability of the automated classifier was compared with three other commonly used classification methods; the automated classifier far outperformed these methods. Conclusions The improvements made allow researchers to automatically separate startle data from noise, and normalize for an individual animal’s mass. These steps ease inter-animal and inter-laboratory comparisons of startle data. PMID:26165984

  8. Origin and function of short-latency inputs to the neural substrates underlying the acoustic startle reflex

    PubMed Central

    Gómez-Nieto, Ricardo; Horta-Júnior, José de Anchieta C.; Castellano, Orlando; Millian-Morell, Lymarie; Rubio, Maria E.; López, Dolores E.

    2014-01-01

    The acoustic startle reflex (ASR) is a survival mechanism of alarm, which rapidly alerts the organism to a sudden loud auditory stimulus. In rats, the primary ASR circuit encompasses three serially connected structures: cochlear root neurons (CRNs), neurons in the caudal pontine reticular nucleus (PnC), and motoneurons in the medulla and spinal cord. It is well-established that both CRNs and PnC neurons receive short-latency auditory inputs to mediate the ASR. Here, we investigated the anatomical origin and functional role of these inputs using a multidisciplinary approach that combines morphological, electrophysiological and behavioral techniques. Anterograde tracer injections into the cochlea suggest that CRNs somata and dendrites receive inputs depending, respectively, on their basal or apical cochlear origin. Confocal colocalization experiments demonstrated that these cochlear inputs are immunopositive for the vesicular glutamate transporter 1 (VGLUT1). Using extracellular recordings in vivo followed by subsequent tracer injections, we investigated the response of PnC neurons after contra-, ipsi-, and bilateral acoustic stimulation and identified the source of their auditory afferents. Our results showed that the binaural firing rate of PnC neurons was higher than the monaural, exhibiting higher spike discharges with contralateral than ipsilateral acoustic stimulations. Our histological analysis confirmed the CRNs as the principal source of short-latency acoustic inputs, and indicated that other areas of the cochlear nucleus complex are not likely to innervate PnC. Behaviorally, we observed a strong reduction of ASR amplitude in monaural earplugged rats that corresponds with the binaural summation process shown in our electrophysiological findings. Our study contributes to understand better the role of neuronal mechanisms in auditory alerting behaviors and provides strong evidence that the CRNs-PnC pathway mediates fast neurotransmission and binaural summation

  9. Longterm-habituation of the startle response in mice is stimulus modality, but not context specific

    PubMed Central

    Pilz, Peter K. D.; Arnold, Stephan W.; Rischawy, Anja T.; Plappert, Claudia F.

    2014-01-01

    In mice, the specificity of longterm-habituation (LTH) of startle was tested in two experiments. In two strains of mice (C57Bl/6 and C3H) there was pronounced LTH over 10 days of acoustic stimulation in two different contexts of startle measurement. (We found LTH to be greater after stimulation with 14 kHz sine stimuli compared to noise or tactile stimuli). A change of context showed LTH to be independent of context, i.e., startle LTH in mice is a non-associative learning process. In the second experiment, 9 days of acoustic or tactile stimulation were given to C57B/6 mice. Both stimulus modalities produced LTH. When on the 10th day stimuli of the other modality were given, in both cases the long term habituated group showed no lower startle amplitude than a non-stimulated control group. This indicates LTH is stimulus-modality specific. Altogether, our results show that in mice—very similar to rats—LTH of startle is stimulus modality, but not context specific. In addition we found two indications that the LTH action site is on the sensory branch of the startle circuit. PMID:24409126

  10. Acoustic startle reactivity while processing reward-related food cues during food deprivation: evidence from women in different menstrual cycle phases and men.

    PubMed

    Ferreira de Sá, Diana S; Plein, Debora E; Schulz, André; Oitzl, Melly S; Blumenthal, Terry D; Schächinger, Hartmut

    2014-02-01

    Previous research has shown that food deprivation enhances the acoustic startle reflex when it is elicited during presentation of visual food cues. Frustrative nonreward may explain this effect, since visual food cues are also rated to be more appetitive and arousing during food deprivation. However, the impact of menstrual cycle and sex on this effect remains unclear, and it is also not known whether this effect is influenced by hunger and motivation to eat. According to a within-study design, 20 healthy women in different menstrual cycle phases and 14 healthy men participated twice, in normal and food-deprived conditions. After 18  h of food deprivation, acoustic startle was attenuated by appetitive nonfood foreground pictures, but enhanced by presentation of food pictures. No differences between menstrual cycle phases and sexes appeared. The effect correlated with hunger changes, suggesting that motivational factors play a role.

  11. 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

  12. 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

  13. Processing of Voiced and Unvoiced Acoustic Stimuli in Musicians

    PubMed Central

    Ott, Cyrill Guy Martin; Langer, Nicolas; Oechslin, Mathias S.; Meyer, Martin; Jäncke, Lutz

    2011-01-01

    Past research has shown that musical training induces changes in the processing of supra-segmental aspects of speech, such as pitch and prosody. The aim of the present study was to determine whether musical expertise also leads to an altered neurophysiological processing of sub-segmental information available in the speech signal, in particular the voice-onset-time. Using high-density EEG-recordings we analyzed the neurophysiological responses to voiced and unvoiced consonant-vowel-syllables and noise-analogs in 26 German speaking adult musicians and non-musicians. From the EEG the N1 amplitude of the event-related potential and two microstates from the topographical EEG analysis (one around the N1 amplitude and one immediately preceding the N1 microstate) were calculated to the different stimuli. Similar to earlier studies the N1 amplitude was different to voiced and unvoiced stimuli in non-musicians with larger amplitudes to voiced stimuli. The more refined microstate analysis revealed that the microstate within the N1 time window was shorter to unvoiced stimuli in non-musicians. For musicians there was no difference for the N1 amplitudes and the corresponding microstates between voiced and unvoiced stimuli. In addition, there was a longer very early microstate preceding the microstate at the N1 time window to non-speech stimuli only in musicians. Taken together, our findings suggest that musicians process unvoiced stimuli (irrespective whether these stimuli are speech or non-speech stimuli) differently than controls. We propose that musicians utilize the same network to analyze unvoiced stimuli as for the analysis of voiced stimuli. As a further explanation it is also possible that musicians devote more neurophysiological resources into the analysis of unvoiced segments. PMID:21922011

  14. Multidimensional scaling between acoustic and electric stimuli in cochlear implant users with contralateral hearing

    PubMed Central

    Vermeire, Katrien; Landsberger, David M.; Schleich, Peter; Van de Heyning, Paul H.

    2013-01-01

    This study investigated the perceptual relationship between acoustic and electric stimuli presented to CI users with functional contralateral hearing. Fourteen subjects with unilateral profound deafness implanted with a MED-EL CI scaled the perceptual differences between pure tones presented to the acoustic hearing ear and electric biphasic pulse trains presented to the implanted ear. The differences were analyzed with a multidimensional scaling (MDS) analysis. Additionally, speech performance in noise was tested using sentence material presented in different spatial configurations while patients listened with both their acoustic hearing and implanted ears. Results of alternating least squares scaling (ALSCAL) analysis consistently demonstrate that a change in place of stimulation is in the same perceptual dimension as a change in acoustic frequency. However, the relative perceptual differences between the acoustic and the electric stimuli varied greatly across subjects. A degree of perceptual separation between acoustic and electric stimulation (quantified by relative dimensional weightings from an INDSCAL analysis) was hypothesized that would indicate a change in perceptual quality, but also be predictive of performance with combined acoustic and electric hearing. Perceptual separation between acoustic and electric stimuli was observed for some subjects. However, no relationship between the degree of perceptual separation and performance was found. PMID:24055624

  15. [Unconscious Acoustical Stimuli Effects on Event-related Potentials in Humans].

    PubMed

    Kopeikina, E A; Choroshich, V V; Aleksandrov, A Y; Ivanova, V Y

    2015-01-01

    Unconscious perception essentially affects human behavior. The main results in this area obtained in experiments with visual stimuli. However, the acoustical stimuli play not less important role in behavior. The main idea of this paper is the electroencephalographic investigation of unconscious acoustical stimulation effects on electro-physiological activity of the brain. For this purpose, the event-related potentials were acquired under unconscious stimulus priming paradigm. The one syllable, three letter length, Russian words and pseudo-words with single letter substitution were used as primes and targets. As a result, we find out that repetition and alternative priming similarly affects the event-related potential's component with 200 ms latency after target application in frontal parietal and temporal areas. Under alternative priming the direction of potential amplitude modification nearby 400 ms was altered for word and semi-word targets. Alternative priming reliably increase ERP's amplitude in 400 ms locality with pseudo-word targets and decrease it under word targets. Taking into account, that all participants were unable to distinguish the applied prime stimuli, we can assume that the event-related potential changes evoked by unconscious perception of acoustical stimuli. The ERP amplitude dynamics revealed in current investigation demonstrate the opportunity of subliminal acoustical stimuli to modulate the electrical activity evoked by verbal acoustical stimulation. PMID:26237945

  16. Effects of Previous Acoustic Experience on Behavioral Responses to Experimental Sound Stimuli and Implications for Research.

    PubMed

    Voellmy, Irene K; Purser, Julia; Simpson, Stephen D; Radford, Andrew N

    2016-01-01

    Ambient noise differs considerably between habitats. Increased ambient noise can affect the physiology and behavior in a variety of taxa. Previous acoustic experience can modify behavior and potentially affect research conclusions in natural and laboratory environments. Acoustic conditions should thus be accounted for, especially in experiments involving experimental sound stimuli. Methods sections should contain acoustic specifications, and a consensus should be achieved over which measurements to include for comparability between researchers. Further investigation of how previous and repeated exposure to sound affects behavior and research conclusions is needed to improve our knowledge of acoustic long-term effects in animal welfare and conservation.

  17. Effects of smoking on the acoustic startle response and prepulse inhibition in smokers with and without posttraumatic stress disorder

    PubMed Central

    Vrana, Scott R.; Calhoun, Patrick S.; McClernon, F. Joseph; Dennis, Michelle F.; Lee, Sherman T.

    2013-01-01

    Rationale Cigarette smokers smoke in part because nicotine helps regulate attention. Prepulse inhibition (PPI) of the startle reflex is a measure of early attentional gating that is reduced in abstinent smokers and in groups with attention regulation difficulties. Attention difficulties are found in people with posttraumatic stress disorder (PTSD). Objectives The aim of this study is to assess whether smoking and abstinence differentially affect the startle response and PPI in smokers with and without PTSD. Methods Startle response and PPI (prepulses at 60, 120, or 240 ms) were measured in smokers with (N=39) and without (N=61) PTSD, while smoking and again while abstinent. Results Participants with PTSD produced both larger magnitude and faster latency startle responses than controls. Across groups, PPI was greater when smoking than when abstinent. The PTSD and control group exhibited different patterns of PPI across prepulse intervals when smoking and when abstinent. Older age was associated with reduced PPI, but only when abstinent from smoking. Conclusions The effects of PTSD on startle magnitude and of smoking on PPI replicate earlier studies. The different pattern of PPI exhibited in PTSD and control groups across prepulse intervals, while smoking and abstinent suggests that previous research on smoking and PPI has been limited by not including longer prepulse intervals, and that nicotine may affect the time course as well as increasing the level of PPI. The reduced PPI among older participants during abstinence suggests that nicotine may play a role in maintaining attention in older smokers, which may motivate continued smoking in older individuals. PMID:23828156

  18. Prediction and perception: Defensive startle modulation.

    PubMed

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

    2015-12-01

    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 uncued 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.

  19. Prediction and perception: Defensive startle modulation.

    PubMed

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

    2015-12-01

    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 uncued 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

  20. 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

  1. Effects of (+)-methamphetamine on path integration and spatial learning, but not locomotor activity or acoustic startle, align with the stress hyporesponsive period in rats.

    PubMed

    Vorhees, Charles V; Skelton, Matthew R; Grace, Curtis E; Schaefer, Tori L; Graham, Devon L; Braun, Amanda A; Williams, Michael T

    2009-05-01

    Rats treated with (+)-methamphetamine (MA) on postnatal days (P) 11-20 exhibit long-term spatial and path integration (Morris water maze (MWM) and Cincinnati water maze (CWM)) learning deficits whereas those treated on P1-10 do not. MA treatment increases corticosterone release in an age-dependent U-shaped pattern that corresponds to the stress hyporesponsive period (SHRP; P4-15). Here we tested the hypothesis that the cognitive effects induced by MA are associated with treatment that begins within the SHRP. Three treatment regimens were compared, P1-10, P6-15, and P11-20. One male/female pair/litter received 0, 10, or 25mg/kg MA/dose (four doses/day at 2h intervals given s.c. with 19-21 litters/regimen). Locomotor activity and acoustic startle were tested as behaviors not predicted to be associated with the SHRP. Cincinnati and Morris water maze findings were consistent with the hypothesis in that MA-treated animals exposed from P6-15 or P11-20 showed impaired learning compared to those exposed from P1-10; however, on probe trials in the Morris water maze, MA-induced memory impairments were not regimen-specific and were contributed to by all treatment regimens. All MA treatment regimens induced reductions in locomotor activity and acoustic startle facilitation as expected. No differential effect on prepulse trials was seen suggesting no impairment in sensory gating. Cognitive deficits from neonatal MA treatment are associated with the SHRP and may be the product of hypothalamic-pituitary-adrenal (HPA) axis dysregulation during critical periods of brain development.

  2. Short-term selective breeding for high and low prepulse inhibition of the acoustic startle response; pharmacological characterization and QTL mapping in the selected lines.

    PubMed

    Hitzemann, Robert; Malmanger, Barry; Belknap, John; Darakjian, Priscila; McWeeney, Shannon

    2008-10-01

    Selective breeding offers several important advantages over using inbred strain panels in detecting genetically correlated traits to the selection phenotype. The purpose of the current study was to selectively breed for prepulse inhibition (PPI) of the acoustic startle response (ASR), to pharmacologically and behaviorally characterize the selected lines and to use the lines for quantitative trait loci (QTL) mapping. Starting with heterogeneous stock mice formed by crossing the C57BL/6J, DBA/2J, BALB/cJ and LP/J inbred strains and using a short-term selective breeding strategy, animals were selected for High and Low PPI. The selection phenotype was the 80 dB prepulse tone (15 dB above the background noise). After five generations of selection, the High and Low lines differed significantly (78.1 +/- 3.1 vs. 45.2 +/- 3.9 [percent inhibition], p < 0.00001). The effects of haloperidol and MK-801 on PPI were not different between the High and Low lines. However, at the highest dose tested (10 mg/kg), the High line was more sensitive than the Low line to the disruptive PPI effects of methamphetamine. The lines did not differ in terms of basal activity or methamphetamine-induced changes in locomotor activity. The High and Low lines were genotyped using a panel of 768 SNPs. Significant QTLs (LOD > 10) were detected on chromosomes 11 and 16 that appeared similar to those detected previously [Hitzemann, R., Bell, J., Rasmussen, E., McCaughran, J. Mapping the genes for the acoustic startle response (ASR) and prepulse inhibition of the ASR in the BXD recombinant inbred series: effect of high-frequency hearing loss and cochlear pathology. In: Willott JF, editor. Handbook of mouse auditory research: From behavior to molecular biology. New York: CRC Press; 2001, p. 441-455.; Petryshen, T. L, Kirby, A., Hammer, R.P. Jr, Purcell, S., O'Leary, S.B., Singer, J.B., et al. Two quantitative trait loci for prepulse inhibition of startle identified on mouse chromosome 16 using chromosome

  3. Modulation of the blink reflex and P3 component of the startle response during an interoceptive challenge.

    PubMed

    Alius, Manuela G; Pané-Farré, Christiane A; Löw, Andreas; Hamm, Alfons O

    2015-01-01

    The blink reflex component of the startle response is potentiated during processing of exteroceptive unpleasant stimuli. In contrast, blink magnitudes are often inhibited during interoceptive challenges. We measured respiration, blink magnitudes, and the P3 component to the acoustic startle probes in 34 participants while breathing against a mild resistance (mask-with-tubing) compared to breathing with no mask. Breathing through a mask with tubing resulted in increased inspiratory resistance as indicated by increased flow rate and tidal volume, a compensatory breathing pattern. Blink magnitudes to probes presented during the mask-with-tubing condition were inhibited compared to no-mask. Likewise, the probe P3 component was smaller during breathing through a mild resistance. These data suggest that startle inhibition during interoceptive challenges might be due to a shift in attention towards the mildly unpleasant interoceptive stimuli.

  4. Generalization of fear-potentiated startle in the presence of auditory cues: a parametric analysis

    PubMed Central

    Norrholm, Seth Davin; Jovanovic, Tanja; Briscione, Maria A.; Anderson, Kemp M.; Kwon, Cliffe K.; Warren, Victor T.; Bosshardt, Lauren; Bradley, Bekh

    2014-01-01

    Intense fear responses observed in trauma-, stressor-, and anxiety-related disorders can be elicited by a wide range of stimuli similar to those that were present during the traumatic event. The present study investigated the experimental utility of fear-potentiated startle paradigms to study this phenomenon, known as stimulus generalization, in healthy volunteers. Fear-potentiated startle refers to a relative increase in the acoustic startle response to a previously neutral stimulus that has been paired with an aversive stimulus. Specifically, in Experiment 1 an auditory pure tone (500 Hz) was used as the conditioned stimulus (CS+) and was reinforced with an unconditioned stimulus (US), an airblast to the larynx. A distinct tone (4000 Hz) was used as the nonreinforced stimulus (CS−) and was never paired with an airblast. Twenty-four hours later subjects underwent Re-training followed by a Generalization test, during which subjects were exposed to a range of generalization stimuli (GS) (250, 1000, 2000, 4000, 8000 Hz). In order to further examine the point at which fear no longer generalizes, a follow-up experiment (Experiment 2) was performed where a 4000 Hz pure tone was used as the CS+, and during the Generalization test, 2000 and 8000 Hz were used as GS. In both Experiment 1 and 2 there was significant discrimination in US expectancy responses on all stimuli during the Generalization Test, indicating the stimuli were perceptually distinct. In Experiment 1, participants showed similar levels of fear-potentiated startle to the GS that were adjacent to the CS+, and discriminated between stimuli that were 2 or more degrees from the CS+. Experiment 2 demonstrated no fear-potentiated startle generalization. The current study is the first to use auditory cues to test generalization of conditioned fear responses; such cues may be especially relevant to combat posttraumatic stress disorder (PTSD) where much of the traumatic exposure may involve sounds. PMID:25368559

  5. Mice Lacking Serotonin 2C Receptors Have increased Affective Responses to Aversive Stimuli

    PubMed Central

    Bonasera, Stephen J.; Schenk, A. Katrin; Luxenberg, Evan J.; Wang, Xidao; Basbaum, Allan; Tecott, Laurence H.

    2015-01-01

    Although central serotonergic systems are known to influence responses to noxious stimuli, mechanisms underlying serotonergic modulation of pain responses are unclear. We proposed that serotonin 2C receptors (5-HT2CRs), which are expressed within brain regions implicated in sensory and affective responses to pain, contribute to the serotonergic modulation of pain responses. In mice constitutively lacking 5-HT2CRs (2CKO mice) we found normal baseline sensory responses to noxious thermal, mechanical and chemical stimuli. In contrast, 2CKO mice exhibited a selective enhancement of affect-related ultrasonic afterdischarge vocalizations in response to footshock. Enhanced affect-related responses to noxious stimuli were also exhibited by 2CKO mice in a fear-sensitized startle assay. The extent to which a brief series of unconditioned footshocks produced enhancement of acoustic startle responses was markedly increased in 2CKO mice. As mesolimbic dopamine pathways influence affective responses to noxious stimuli, and these pathways are disinhibited in 2CKO mice, we examined the sensitivity of footshock-induced enhancement of startle to dopamine receptor blockade. Systemic administration of the dopamine D2/D3 receptor antagonist raclopride selectively reduced footshock-induced enhancement of startle without influencing baseline acoustic startle responses. We propose that 5-HT2CRs regulate affective behavioral responses to unconditioned aversive stimuli through mechanisms involving the disinhibition of ascending dopaminergic pathways. PMID:26630489

  6. Expression of freezing and fear-potentiated startle during sustained fear in mice.

    PubMed

    Daldrup, T; Remmes, J; Lesting, J; Gaburro, S; Fendt, M; Meuth, P; Kloke, V; Pape, H-C; Seidenbecher, T

    2015-03-01

    Fear-potentiated acoustic startle paradigms have been used to investigate phasic and sustained components of conditioned fear in rats and humans. This study describes a novel training protocol to assess phasic and sustained fear in freely behaving C57BL/6J mice, using freezing and/or fear-potentiated startle as measures of fear, thereby, if needed, allowing in vivo application of various techniques, such as optogenetics, electrophysiology and pharmacological intervention, in freely behaving animals. An auditory Pavlovian fear conditioning paradigm, with pseudo-randomized conditioned-unconditioned stimulus presentations at various durations, is combined with repetitive brief auditory white noise burst presentations during fear memory retrieval 24 h after fear conditioning. Major findings are that (1) a motion sensitive platform built on mechano-electrical transducers enables measurement of startle responses in freely behaving mice, (2) absence or presence of startle stimuli during retrieval as well as unpredictability of a given threat determine phasic and sustained fear response profiles and (3) both freezing and startle responses indicate phasic and sustained components of behavioral fear, with sustained freezing reflecting unpredictability of conditioned stimulus (CS)/unconditioned stimulus (US) pairings. This paradigm and available genetically modified mouse lines will pave the way for investigation of the molecular and neural mechanisms relating to the transition from phasic to sustained fear.

  7. Cortisol levels in hair reflect behavioural reactivity of dogs to acoustic stimuli.

    PubMed

    Siniscalchi, M; McFarlane, J R; Kauter, K G; Quaranta, A; Rogers, L J

    2013-02-01

    Cortisol levels in hair samples were examined in fourteen domestic dogs and related to the dogs' responses to different acoustic stimuli. Stimuli were playbacks of species-typical vocalizations recorded during three different situations ("disturbance", "isolation" and "play" barks) and the sounds of a thunderstorm. Hair samples were collected at 9:00 h and 17:00 h two weeks after the behavioural tests. Results showed that behavioural reactivity to playback of the various stimuli correlates with cortisol levels in hair samples collected at 9:00 h, and the same was the case for the separate measures of behaviour (i.e. hiding, running away, seeking attention from the tester, panting and lowering of the body posture). Hence, levels of cortisol in hair appear to reflect the dog's chronic state of emotional reactivity, or temperament. PMID:22449333

  8. Cortisol levels in hair reflect behavioural reactivity of dogs to acoustic stimuli.

    PubMed

    Siniscalchi, M; McFarlane, J R; Kauter, K G; Quaranta, A; Rogers, L J

    2013-02-01

    Cortisol levels in hair samples were examined in fourteen domestic dogs and related to the dogs' responses to different acoustic stimuli. Stimuli were playbacks of species-typical vocalizations recorded during three different situations ("disturbance", "isolation" and "play" barks) and the sounds of a thunderstorm. Hair samples were collected at 9:00 h and 17:00 h two weeks after the behavioural tests. Results showed that behavioural reactivity to playback of the various stimuli correlates with cortisol levels in hair samples collected at 9:00 h, and the same was the case for the separate measures of behaviour (i.e. hiding, running away, seeking attention from the tester, panting and lowering of the body posture). Hence, levels of cortisol in hair appear to reflect the dog's chronic state of emotional reactivity, or temperament.

  9. Developmental Trajectories of Auditory Cortex Synaptic Structures and Gap-Prepulse Inhibition of Acoustic Startle Between Early Adolescence and Young Adulthood in Mice.

    PubMed

    Moyer, Caitlin E; Erickson, Susan L; Fish, Kenneth N; Thiels, Edda; Penzes, Peter; Sweet, Robert A

    2016-05-01

    Cortical excitatory and inhibitory synapses are disrupted in schizophrenia, the symptoms of which often emerge during adolescence, when cortical excitatory synapses undergo pruning. In auditory cortex, a brain region implicated in schizophrenia, little is known about the development of excitatory and inhibitory synapses between early adolescence and young adulthood, and how these changes impact auditory cortex function. We used immunohistochemistry and quantitative fluorescence microscopy to quantify dendritic spines and GAD65-expressing inhibitory boutons in auditory cortex of early adolescent, late adolescent, and young adult mice. Numbers of spines decreased between early adolescence and young adulthood, during which time responses increased in an auditory cortex-dependent sensory task, silent gap-prepulse inhibition of the acoustic startle reflex (gap-PPI). Within-bouton GAD65 protein and GAD65-expressing bouton numbers decreased between late adolescence and young adulthood, a delay in onset relative to spine and gap-PPI changes. In mice lacking the spine protein kalirin, there were no significant changes in spine number, within-bouton GAD65 protein, or gap-PPI between adolescence and young adulthood. These results illustrate developmental changes in auditory cortex spines, inhibitory boutons, and auditory cortex function between adolescence and young adulthood, and provide insights into how disrupted adolescent neurodevelopment could contribute to auditory cortex synapse pathology and auditory impairments.

  10. 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.

  11. Discrimination of Speech Stimuli Based on Neuronal Response Phase Patterns Depends on Acoustics But Not Comprehension

    PubMed Central

    Poeppel, David

    2010-01-01

    Speech stimuli give rise to neural activity in the listener that can be observed as waveforms using magnetoencephalography. Although waveforms vary greatly from trial to trial due to activity unrelated to the stimulus, it has been demonstrated that spoken sentences can be discriminated based on theta-band (3–7 Hz) phase patterns in single-trial response waveforms. Furthermore, manipulations of the speech signal envelope and fine structure that reduced intelligibility were found to produce correlated reductions in discrimination performance, suggesting a relationship between theta-band phase patterns and speech comprehension. This study investigates the nature of this relationship, hypothesizing that theta-band phase patterns primarily reflect cortical processing of low-frequency (<40 Hz) modulations present in the acoustic signal and required for intelligibility, rather than processing exclusively related to comprehension (e.g., lexical, syntactic, semantic). Using stimuli that are quite similar to normal spoken sentences in terms of low-frequency modulation characteristics but are unintelligible (i.e., their time-inverted counterparts), we find that discrimination performance based on theta-band phase patterns is equal for both types of stimuli. Consistent with earlier findings, we also observe that whereas theta-band phase patterns differ across stimuli, power patterns do not. We use a simulation model of the single-trial response to spoken sentence stimuli to demonstrate that phase-locked responses to low-frequency modulations of the acoustic signal can account not only for the phase but also for the power results. The simulation offers insight into the interpretation of the empirical results with respect to phase-resetting and power-enhancement models of the evoked response. PMID:20484530

  12. 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

  13. [Evoked potentials to joint presentation of photic and acoustic stimuli in the human EEG].

    PubMed

    Boldyreva, G N; Gnezditskiĭ, V V

    1977-01-01

    The results are outlined of a comparative estimation of averaged EP recorded in response to simultaneous and separate presentation of photic and acoustic stimuli on EEG of fifteen healthy subjects and twelve patients with focal lesions of the diencephalic structures. Investigation of the EP components and integral-temporal parameters has revealed that in healthy subjects EP to a combined heteromodal stimulation considerably exceeded by amplitude the one recorded in response to a separate presentation of stimuli. In case of lesion of the diencephalic formations, the converging effect of polysensory stimulation for the main waves of the response was less pronounced than in healthy subjects. At the same time, in pathological cases the summation effect of the afteraction potential (recorded after the main EP components as a slow negative oscillation) was manifested most distinctly, especially in the central zone of the cortex.

  14. Intermodal transfer in temporal discrimination. [of visual and acoustic stimuli duration

    NASA Technical Reports Server (NTRS)

    Warm, J. S.; Stutz, R. M.; Vassolo, P. A.

    1975-01-01

    This study determined if training for accuracy in temporal discrimination would transfer across sensory modalities. A fractionation method was used in which subjects bisected the durations of acoustic and visual signals at three standard intervals (6, 12, and 18 sec). Absolute error was the performance index. Half of the subjects were trained with acoustic stimuli and then tested in vision; the remainder were trained in vision and tested in audition. Similar negatively accelerated acquisition functions were noted for both modalities. Positive intermodal transfer, characterized by symmetry across modalities, was obtained at all standard durations. The results were considered to provide support for the notion that a common mechanism underlies temporal discriminations in different sensory systems.

  15. Age-related affective modulation of the startle eyeblink response: older adults startle most when viewing positive pictures.

    PubMed

    Feng, Michelle C; Courtney, Christopher G; Mather, Mara; Dawson, Michael E; Davison, Gerald C

    2011-09-01

    Previous studies reveal age by valence interactions in attention and memory, such that older adults focus relatively more on positive and relatively less on negative stimuli than younger adults. In the current study, eyeblink startle response was used to measure differences in emotional reactivity to images that were equally arousing to both age groups. Viewing positive and negative pictures from the International Affective Picture System had opposite effects on startle modulation for older and younger adults. Younger adults showed the typical startle blink pattern, with potentiated startle when viewing negative pictures compared to positive pictures. Older adults, on the other hand, showed the opposite pattern, with potentiated startle when viewing positive pictures compared to viewing negative and neutral pictures. Potential underlying mechanisms for this interaction are evaluated. This pattern suggests that, compared with younger adults, older adults are more likely to spontaneously suppress responses to negative stimuli and process positive stimuli more deeply.

  16. Nicotine blocks apomorphine-induced disruption of prepulse inhibition of the acoustic startle in rats: possible involvement of central nicotinic alpha7 receptors.

    PubMed

    Suemaru, Katsuya; Yasuda, Kayo; Umeda, Kenta; Araki, Hiroaki; Shibata, Kazuhiko; Choshi, Tominari; Hibino, Satoshi; Gomita, Yutaka

    2004-07-01

    Nicotine has been reported to normalize deficits in auditory sensory gating in the cases of schizophrenia, suggesting an involvement of nicotinic acetylcholine receptors in attentional abnormalities. However, the mechanism remains unclear. The present study investigated the effects of nicotine on the disruption of prepulse inhibition (PPI) of the acoustic startle response induced by apomorphine or phencyclidine in rats. Over the dose range tested, nicotine (0.05-1 mg kg(-1), s.c.) did not disrupt PPI. Neither methyllycaconitine (0.5-5 mg kg(-1), s.c.), an alpha(7) nicotinic receptor antagonist, nor dihydro-beta-erythroidine (0.5-2 mg kg(-1), s.c.), an alpha(4)beta(2) nicotinic receptor antagonist, had any effect on PPI. Nicotine (0.01-0.2 mg kg(-1), s.c.) dose-dependently reversed the disruption of PPI induced by apomorphine (1 mg kg(-1), s.c.), but had no effect on the disruption of PPI induced by phencyclidine (2 mg kg(-1), s.c.). The reversal of apomorphine-induced PPI disruption by nicotine (0.2 mg kg(-1)) was eliminated by mecamylamine (1 mg kg(-1), i.p.), but not by hexamethonium (10 mg kg(-1), i.p.), indicating the involvement of central nicotinic receptors. The antagonistic action of nicotine on apomorphine-induced PPI disruption was dose-dependently blocked by methyllycaconitine (1 and 2 mg kg(-1), s.c.). However, dihydro-beta-erythroidine (1 and 2 mg kg(-1), s.c.) had no effect. These results suggest that nicotine reverses the disruption of apomorphine-induced PPI through central alpha(7) nicotinic receptors.

  17. Effect of stimuli presentation method on perception of room size using only acoustic cues

    NASA Astrophysics Data System (ADS)

    Hunt, Jeffrey Barnabas

    People listen to music and speech in a large variety of rooms and many room parameters, including the size of the room, can drastically affect how well the speech is understood or the music enjoyed. While multi-modal (typically hearing and sight) tests may be more realistic, in order to isolate what acoustic cues listeners use to determine the size of a room, a listening-only tests is conducted here. Nearly all of the studies to-date on the perception of room volume using acoustic cues have presented the stimuli only over headphones and these studies have reported that, in most cases, the perceived room volume is more highly correlated with the perceived reverberation (reverberance) than with actual room volume. While reverberance may be a salient acoustic cue used for the determination or room size, the actual sound field in a room is not accurately reproduced when presented over headphones and it is thought that some of the complexities of the sound field that relate to perception of geometric volume, specifically directional information of reflections, may be lost. It is possible that the importance of reverberance may be overemphasized when using only headphones to present stimuli so a comparison of room-size perception is proposed where the sound field (from modeled and recorded impulse responses) is presented both over headphones and also over a surround system using higher order ambisonics to more accurately produce directional sound information. Major results are that, in this study, no difference could be seen between the two presentation methods and that reverberation time is highly correlated to room-size perception while real room size is not.

  18. 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…

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

    PubMed

    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.

  20. 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

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

    PubMed

    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

  2. Physiological and behavioral reactions elicited by simulated and real-life visual and acoustic helicopter stimuli in dairy goats

    PubMed Central

    2011-01-01

    Background Anecdotal reports and a few scientific publications suggest that flyovers of helicopters at low altitude may elicit fear- or anxiety-related behavioral reactions in grazing feral and farm animals. We investigated the behavioral and physiological stress reactions of five individually housed dairy goats to different acoustic and visual stimuli from helicopters and to combinations of these stimuli under controlled environmental (indoor) conditions. The visual stimuli were helicopter animations projected on a large screen in front of the enclosures of the goats. Acoustic and visual stimuli of a tractor were also presented. On the final day of the study the goats were exposed to two flyovers (altitude 50 m and 75 m) of a Chinook helicopter while grazing in a pasture. Salivary cortisol, behavior, and heart rate of the goats were registered before, during and after stimulus presentations. Results The goats reacted alert to the visual and/or acoustic stimuli that were presented in their room. They raised their heads and turned their ears forward in the direction of the stimuli. There was no statistically reliable rise of the average velocity of moving of the goats in their enclosure and no increase of the duration of moving during presentation of the stimuli. Also there was no increase in heart rate or salivary cortisol concentration during the indoor test sessions. Surprisingly, no physiological and behavioral stress responses were observed during the flyover of a Chinook at 50 m, which produced a peak noise of 110 dB. Conclusions We conclude that the behavior and physiology of goats are unaffected by brief episodes of intense, adverse visual and acoustic stimulation such as the sight and noise of overflying helicopters. The absence of a physiological stress response and of elevated emotional reactivity of goats subjected to helicopter stimuli is discussed in relation to the design and testing schedule of this study. PMID:21496239

  3. Affect modulated startle in schizophrenia: subjective experience matters.

    PubMed

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

    2014-12-15

    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.

  4. Emotional processing and rTMS: does inhibitory theta burst stimulation affect the human startle reflex?

    PubMed

    Vennewald, Nadja; Winter, Bernward; Limburg, Karina; Diemer, Julia; Notzon, Swantje; Fohrbeck, Inga; Arolt, Volker; Domschke, Katharina; Pauli, Paul; Zwanzger, Peter

    2016-10-01

    Repetitive transcranial magnetic stimulation (rTMS) enables the local and non-invasive modulation of cortical activity and has proved to achieve antidepressant effects. To a lesser extent, rTMS is investigated as a treatment option for anxiety disorders. As the prefrontal cortex and the amygdala represent key components of human emotion regulation, we investigated how prefrontally applied rTMS affects the responsiveness of the subcortical amygdala during a fear-relevant study paradigm to examine potential cortico-limbic effects. Sham-controlled, randomised inhibitory rTMS (continuous theta burst stimulation, TBS) was applied to 102 healthy subjects (female = 54) over the right dorsolateral prefrontal cortex. Subsequently, the emotion-potentiated (unpleasant, neutral, and pleasant International Affective Picture System pictures) acoustic startle response was investigated. Subjective anxiety ratings (anxiety sensitivity, trait and state anxiety) were considered. Picture category affected the startle magnitude as expected for both TBS intervention groups (highest startle response for unpleasant, lowest for pleasant pictures). However, no modulatory effects of TBS on startle potentiation were discerned. No significant interaction effects of TBS intervention, subjective anxiety ratings, and gender were identified. Interestingly, startle habituation was influenced by TBS intervention on a trend-level, with verum TBS leading to an accelerated habituation. We found no evidence for the hypothesis that prefrontal inhibitory TBS affects the responsiveness of the amygdala during the presentation of emotionally relevant stimuli in healthy subjects. Instead, we found accelerated habituation under verum TBS on a statistical trend-level. Hence, some preliminary hints for modulatory effects of inhibitory TBS on basic learning mechanisms could be found.

  5. Startle activation is additive with voluntary cortical activation irrespective of stimulus modality.

    PubMed

    Maslovat, Dana; Drummond, Neil M; Carter, Michael J; Carlsen, Anthony N

    2015-10-01

    When a startling acoustic stimulus (SAS) is presented during a simple reaction time (RT) task, it can trigger the prepared response through an involuntary initiation pathway. Previous research modelling the effects of presenting a SAS at various intervals following a non-startling auditory imperative signal (IS) suggested that involuntary initiation-related neural activation is additive with the voluntary initiation processes. The current study tested the predictions of this additive model when the SAS and IS are of different modalities by using a visual rather than auditory go-signal. Because voluntary RT latencies are delayed for visual stimuli compared to acoustic stimuli, it was hypothesised that the time course of additive activation would be similarly delayed. Participants performed 150 RT trials requiring a targeted 20° wrist extension task with a SAS presented 0-125 ms following a visual go-signal. Results were not different to those predicted by an additive model (p=0.979), yet were significantly different to those predicted by a horse-race model (p=0.037), indicating a joint contribution of voluntary and involuntary activation, even when the IS and SAS are of different modalities. Furthermore, the results indicated that voluntary RT differences due to stimulus modality are attributable to processes that occur prior to the increase in initiation-related activation.

  6. 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. PMID:23166784

  7. 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.

  8. 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

  9. Automatic facial responses to affective stimuli in high-functioning adults with autism spectrum disorder.

    PubMed

    Mathersul, Danielle; McDonald, Skye; Rushby, Jacqueline A

    2013-01-17

    Individuals with autism spectrum disorder (ASD) demonstrate atypical behavioural responses to affective stimuli, although the underlying mechanisms remain unclear. Investigating automatic responses to these stimuli may help elucidate these mechanisms. 18 high-functioning adults with ASDs and 18 typically developing controls viewed 54 extreme pleasant (erotica), extreme unpleasant (mutilations), and non-social neutral images from the International Affective Picture System (IAPS). Two-thirds of images received an acoustic startle probe 3s post-picture onset. Facial electromyography (EMG) activity (orbicularis, zygomaticus, corrugator), skin conductance (SCR) and cardiac responses were recorded. The adults with ASDs demonstrated typical affective startle modulation and automatic facial EMG responses but atypical autonomic (SCRs and cardiac) responses, suggesting a failure to orient to, or a deliberate effort to disconnect from, socially relevant stimuli (erotica, mutilations). These results have implications for neural systems known to underlie affective processes, including the orbitofrontal cortex and amygdala. PMID:23142408

  10. 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.

  11. Role of nicotinic receptors in the lateral habenula in the attenuation of amphetamine-induced prepulse inhibition deficits of the acoustic startle response in rats

    PubMed Central

    Larrauri, José A.; Burke, Dennis A.; Hall, Brandon J.; Levin, Edward D.

    2015-01-01

    Rationale Prepulse inhibition (PPI) refers to the reduction of the startle response magnitude when a startling stimulus is closely preceded by a weak stimulus. PPI is commonly used to measure sensorimotor gating. In rats, the PPI reduction induced by the dopamine-agonist apomorphine can be reversed by systemic administration of nicotine. A high concentration of nicotinic receptors is found in the lateral habenula (LHb), an epithalamic structure with efferent projections to brain regions involved in the modulation of PPI, which has been shown to regulate the activity of midbrain dopamine neurons. Objectives The prospective role of nicotinic receptors in the LHb in the regulation of PPI was assessed in this study, using different pharmacological models of sensorimotor gating deficits. Methods Interactions between systemic amphetamine and haloperidol and intra-LHb infusions of mecamylamine (10 µg/side) or nicotine (30 µg/side) on PPI were analyzed in Experiments 1 and 2. Intra-LHb infusions of different nicotine doses (25, and 50 µg/side) and their interactions with systemic administration of amphetamine or dizocilpine on PPI were examined in Experiments 3 and 4. Results Infusions of nicotine into the LHb dose-dependently attenuated amphetamine-induced PPI deficits, but had no effect on PPI disruptions caused by dizocilpine. Intra-LHb mecamylamine infusions did not affect PPI nor interact with dopaminergic manipulations. Conclusions These results are congruent with previous reports of systemic nicotine effects on PPI, suggesting a role of the LHb in the attenuation of sensorimotor gating deficits caused by the hyperactivity of dopamine systems. PMID:25912180

  12. Exposure to acoustic stimuli promotes the development and differentiation of neural stem cells from the cochlear nuclei through the clusterin pathway.

    PubMed

    Xue, Tao; Wei, Li; Zha, Ding-Jun; Qiao, Li; Lu, Lian-Jun; Chen, Fu-Quan; Qiu, Jian-Hua

    2015-03-01

    Stem cell therapy has attracted widespread attention for a number of diseases. Recently, neural stem cells (NSCs) from the cochlear nuclei have been identified, indicating a potential direction for the treatment of sensorineural hearing loss. Acoustic stimuli play an important role in the development of the auditory system. In this study, we aimed to determine whether acoustic stimuli induce NSC development and differentiation through the upregulation of clusterin (CLU) in NSCs isolated from the cochlear nuclei. To further clarify the underlying mechanisms involved in the development and differentiation of NSCs exposed to acoustic stimuli, we successfully constructed animal models in which was CLU silenced by an intraperitoneal injection of shRNA targeting CLI. As expected, the NSCs from rats treated with LV-CLU shRNA exhibited a lower proliferation ratio when exposed to an augmented acoustic environment (AAE). Furthermore, the inhibition of cell apoptosis induced by exposure to AAE was abrogated after silencing the expression of the CLU gene. During the differentiation of acoustic stimuli-exposed stem cells into neurons, the number of astrocytes was significantly reduced, as evidenced by the expression of the cell markers, microtubule associated protein‑2 (MAP-2) and glial fibrillary acidic protein (GFAP), which was markedly inhibited when the CLU gene was silenced. Our results indicate that acoustic stimuli may induce the development and differentiation of NSCs from the cochlear nucleus mainly through the CLU pathway. Our study suggests that CLU may be a novel target for the treatment of sensorineural hearing loss.

  13. The Gap-Startle Paradigm for Tinnitus Screening in Animal Models: Limitations and Optimization

    PubMed Central

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

    2012-01-01

    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 rats neck. Furthermore, it was found that transient unilateral conductive hearing loss, which was not likely to induce tinnitus, caused an impairment in gap prepulse inhibition

  14. Affective modulation of eyeblink startle with reward and threat.

    PubMed

    Skolnick, Alexander I; Davidson, Richard I

    2002-11-01

    An emotion-modulated acoustic startle paradigm for inducing positive and negative affect was used to address pregoal and postgoal affect. Participants played a computerized lottery task in which they chose digits that could match a subsequently displayed, random set of numbers. In the positive conditions, matches led to monetary rewards. In the negative condition, matches led to an aversive noise blast. In three experiments, we found eyeblink startle magnitude was potentiated just prior to feedback concerning reward outcome, suppressed following the feedback that a monetary reward was won, and potentiated when threatened with an aversive noise. When presented with a 0%, 45%, 90%, or 100% chance of winning, higher probabilities suppressed startle response after feedback whereas the 45% trials did not. These data indicate that postgoal positive affect (winning reward) reliably suppressed the startle response whereas pregoal positive affect did not.

  15. ENU-mutagenesis mice with a non-synonymous mutation in Grin1 exhibit abnormal anxiety-like behaviors, impaired fear memory, and decreased acoustic startle response

    PubMed Central

    2013-01-01

    Background The Grin1 (glutamate receptor, ionotropic, NMDA1) gene expresses a subunit of N-methyl-D-aspartate (NMDA) receptors that is considered to play an important role in excitatory neurotransmission, synaptic plasticity, and brain development. Grin1 is a candidate susceptibility gene for neuropsychiatric disorders, including schizophrenia, bipolar disorder, and attention deficit/hyperactivity disorder (ADHD). In our previous study, we examined an N-ethyl-N-nitrosourea (ENU)-generated mutant mouse strain (Grin1Rgsc174/Grin1+) that has a non-synonymous mutation in Grin1. These mutant mice showed hyperactivity, increased novelty-seeking to objects, and abnormal social interactions. Therefore, Grin1Rgsc174/Grin1+ mice may serve as a potential animal model of neuropsychiatric disorders. However, other behavioral characteristics related to these disorders, such as working memory function and sensorimotor gating, have not been fully explored in these mutant mice. In this study, to further investigate the behavioral phenotypes of Grin1Rgsc174/Grin1+ mice, we subjected them to a comprehensive battery of behavioral tests. Results There was no significant difference in nociception between Grin1Rgsc174/Grin1+ and wild-type mice. The mutants did not display any abnormalities in the Porsolt forced swim and tail suspension tests. We confirmed the previous observations that the locomotor activity of these mutant mice increased in the open field and home cage activity tests. They displayed abnormal anxiety-like behaviors in the light/dark transition and the elevated plus maze tests. Both contextual and cued fear memory were severely deficient in the fear conditioning test. The mutant mice exhibited slightly impaired working memory in the eight-arm radial maze test. The startle amplitude was markedly decreased in Grin1Rgsc174/Grin1+ mice, whereas no significant differences between genotypes were detected in the prepulse inhibition (PPI) test. The mutant mice showed no obvious

  16. 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

  17. Cardiac modulation of startle is altered in depersonalization-/derealization disorder: Evidence for impaired brainstem representation of baro-afferent neural traffic.

    PubMed

    Schulz, André; Matthey, Jan Hendrik; Vögele, Claus; Schaan, Violetta; Schächinger, Hartmut; Adler, Julia; Beutel, Manfred E; Michal, Matthias

    2016-06-30

    Patients with depersonalization-/derealization disorder (DPD) show altered heartbeat-evoked brain potentials, which are considered psychophysiological indicators of cortical representation of visceral-afferent neural signals. The aim of the current investigation was to clarify whether the impaired CNS representation of visceral-afferent neural signals in DPD is restricted to the cortical level or is also present in sub-cortical structures. We used cardiac modulation of startle (CMS) to assess baro-afferent signal transmission at brainstem level in 22 DPD and 23 healthy control individuals. The CMS paradigm involved acoustic startle stimuli (105dB(A), 50ms) elicited 0, 100, 200, 300, 400 and 500ms after a cardiac R-wave. In healthy control individuals, we observed lower startle responses at 100 and 300ms than at 0 and 400ms after an R-wave. In DPD patients, no effect of the cardiac cycle on startle response magnitude was found. We conclude that the representation of visceral-afferent neural signals at brainstem level may be deficient in DPD. This effect may be due to increased peripheral sympathetic tone or to dysregulated signal processing at brainstem level. PMID:27078753

  18. Mescaline increases startle responding equally in normal and raphe-lesioned rats.

    PubMed

    Geyer, M A; Rose, G J; Petersen, L R

    1979-02-01

    To test the possible involvement of serotonin-containing cells of the midbrain in mediating the effects of mescaline on startle responding, electrolytic lesions were made in either the dorsal or median raphe nucleus in rats. Decreases in either striatal or hippocampal tryptophan hydroxylase activity confirmed the effectiveness of the lesions. One week later, startle was measured in response to 30 air-puff stimuli for each rat. Median, but not dorsal, raphe lesions increased startle magnitudes throughout the test session. The following day each group was divided into matched halves and were given 60 trials, 30 minutes after intraperitoneal injection of either saline or 10 mg/kg mescaline. Despite the large differences in baseline startle among the groups, mescaline produced comparable 25% increases in startle magnitudes in both sham- and raphe-lesioned animals. This result fails to support the hypothesis that increased startle responding produced by mescaline is mediated by the midbrain raphe nuclei.

  19. The involvement of ventral tegmental area cholinergic muscarinic receptors in classically conditioned fear expression as measured with fear-potentiated startle.

    PubMed

    Greba, Q; Munro, L J; Kokkinidis, L

    2000-07-01

    Accumulating evidence suggests that dopamine (DA) neurons in the ventral tegmental area (VTA) contribute to the complex amygdala-based neurocircuitry that mediates fear-motivated behaviors. Because of acetylcholine's (ACh) role in DA neuronal activation, the involvement of VTA cholinergic muscarinic receptors in Pavlovian conditioned fear responding was evaluated in the present study. Fear-potentiated startle was used to assess the effects of intraVTA infused methylscopolamine on conditioned fear performance in laboratory rats. Application of this nonspecific muscarinic receptor antagonist to VTA neurons was observed to inhibit the ability of a conditioned stimulus (CS) previously paired with footshock to enhance the amplitude of the acoustic startle reflex. Doses of methylscopolamine that blocked conditioned fear expression did not alter baseline sensorimotor responding. These results identify ACh neurotransmission in the VTA as a potential excitatory mechanism underlying the fear-arousing properties of threatening environmental stimuli.

  20. The biological significance of acoustic stimuli determines ear preference in the music frog.

    PubMed

    Xue, Fei; Fang, Guangzhan; Yang, Ping; Zhao, Ermi; Brauth, Steven E; Tang, Yezhong

    2015-03-01

    Behavioral and neurophysiological studies support the idea that right ear advantage (REA) exists for perception of conspecific vocal signals in birds and mammals. Nevertheless, few studies have focused on anuran species that typically communicate through vocalization. The present study examined the direction and latencies of orientation behaviors in Emei music frogs (Babina daunchina) produced in response to six auditory stimuli emitted by a speaker placed directly behind the subjects. The stimuli included male advertisement calls produced from within burrow nests, which have been shown to be highly sexually attractive (HSA), calls produced from outside burrows, which are of low sexual attractiveness (LSA), screech calls produced when frogs are attacked by snakes, white noise, thunder and silence. For all sound stimuli except the screech, the frogs preferentially turned to the right. Right ear preference was strongest for HSA calls. For the screech and thunder stimuli, there was an increased tendency for subjects to move further from the speaker rather than turning. These results support the idea that in anurans, right ear preference is associated with perception of positive or neutral signals such as the conspecific advertisement call and white noise, while a left ear preference is associated with perception of negative signals such as predatory attack.

  1. Oxytocin Reduces Background Anxiety in a Fear-Potentiated Startle Paradigm: Peripheral vs Central Administration

    PubMed Central

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

    2011-01-01

    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. PMID:21796104

  2. 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).

  3. Neurons Differentiated from Transplanted Stem Cells Respond Functionally to Acoustic Stimuli in the Awake Monkey Brain.

    PubMed

    Wei, Jing-Kuan; Wang, Wen-Chao; Zhai, Rong-Wei; Zhang, Yu-Hua; Yang, Shang-Chuan; Rizak, Joshua; Li, Ling; Xu, Li-Qi; Liu, Li; Pan, Ming-Ke; Hu, Ying-Zhou; Ghanemi, Abdelaziz; Wu, Jing; Yang, Li-Chuan; Li, Hao; Lv, Long-Bao; Li, Jia-Li; Yao, Yong-Gang; Xu, Lin; Feng, Xiao-Li; Yin, Yong; Qin, Dong-Dong; Hu, Xin-Tian; Wang, Zheng-Bo

    2016-07-26

    Here, we examine whether neurons differentiated from transplanted stem cells can integrate into the host neural network and function in awake animals, a goal of transplanted stem cell therapy in the brain. We have developed a technique in which a small "hole" is created in the inferior colliculus (IC) of rhesus monkeys, then stem cells are transplanted in situ to allow for investigation of their integration into the auditory neural network. We found that some transplanted cells differentiated into mature neurons and formed synaptic input/output connections with the host neurons. In addition, c-Fos expression increased significantly in the cells after acoustic stimulation, and multichannel recordings indicated IC specific tuning activities in response to auditory stimulation. These results suggest that the transplanted cells have the potential to functionally integrate into the host neural network.

  4. Neurons Differentiated from Transplanted Stem Cells Respond Functionally to Acoustic Stimuli in the Awake Monkey Brain.

    PubMed

    Wei, Jing-Kuan; Wang, Wen-Chao; Zhai, Rong-Wei; Zhang, Yu-Hua; Yang, Shang-Chuan; Rizak, Joshua; Li, Ling; Xu, Li-Qi; Liu, Li; Pan, Ming-Ke; Hu, Ying-Zhou; Ghanemi, Abdelaziz; Wu, Jing; Yang, Li-Chuan; Li, Hao; Lv, Long-Bao; Li, Jia-Li; Yao, Yong-Gang; Xu, Lin; Feng, Xiao-Li; Yin, Yong; Qin, Dong-Dong; Hu, Xin-Tian; Wang, Zheng-Bo

    2016-07-26

    Here, we examine whether neurons differentiated from transplanted stem cells can integrate into the host neural network and function in awake animals, a goal of transplanted stem cell therapy in the brain. We have developed a technique in which a small "hole" is created in the inferior colliculus (IC) of rhesus monkeys, then stem cells are transplanted in situ to allow for investigation of their integration into the auditory neural network. We found that some transplanted cells differentiated into mature neurons and formed synaptic input/output connections with the host neurons. In addition, c-Fos expression increased significantly in the cells after acoustic stimulation, and multichannel recordings indicated IC specific tuning activities in response to auditory stimulation. These results suggest that the transplanted cells have the potential to functionally integrate into the host neural network. PMID:27425612

  5. Emotion regulation of the affect-modulated startle reflex during different picture categories.

    PubMed

    Conzelmann, Annette; McGregor, Victoria; Pauli, Paul

    2015-09-01

    Previous studies on emotion regulation of the startle reflex found an increase in startle amplitude from down-, to non-, to up-regulation for pleasant and unpleasant stimuli. We wanted to clarify whether this regulation effect remains stable for different picture categories within pleasant and unpleasant picture sets. We assessed startle amplitude of 31 participants during down-, non-, or up-regulation of feelings elicited by pleasant erotic and adventure and unpleasant victim and threat pictures. Startle amplitude was smaller during adventure and erotic compared to victim and threat pictures and increased from down-, to non-, to up-regulation independently of the picture category. Results indicate that the motivational priming effect on startle modulation elicited by different picture categories is independent of emotion regulation instructions. In addition, the emotion regulation effect is independent of motivational priming effects. PMID:26061976

  6. 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

  7. Emotion Potentiated Startle in Fragile X Syndrome

    PubMed Central

    Ballinger, Elizabeth C.; Cordeiro, Lisa; Chavez, Alyssa D.; Hagerman, Randi J.; Hessl, David R.

    2014-01-01

    Social avoidance and anxiety are prevalent in fragile X syndrome (FXS) and are potentially mediated by the amygdala, a brain region critical for social behavior. Unfortunately, fMRI investigation of the amygdala in FXS is limited by the difficulties experienced by intellectually impaired and anxious participants. We investigated the relationship between social avoidance and emotion-potentiated startle, a probe of amygdala activation, in children and adolescents with FXS, developmental disability without FXS (DD), and typical development. Individuals with FXS or DD demonstrated significantly reduced potentiation to fearful faces than a typically developing control group (p<.05). However, among individuals with FXS, social avoidance correlated positively with fearful-face potentiation (p<.05). This suggests that general intellectual disability blunts amygdalar response, but differential amygdala responsiveness to social stimuli contributes to phenotypic variability among individuals with FXS. PMID:24816942

  8. Meditation and the Startle Response: A Case Study

    PubMed Central

    Levenson, Robert W.; Ekman, Paul; Ricard, Matthieu

    2013-01-01

    The effects of two kinds of meditation (open presence and focused) on the facial and physiological aspects of the defensive response to an aversive startle stimulus were studied in a Buddhist monk with approximately 40 years of meditation experience. The participant was exposed to a 115 db, 100 ms acoustic startle stimulus under the two meditation conditions, a distraction condition (to control for cognitive and attentional load) and an unanticipated condition (startle presented without warning or instruction). A completely counterbalanced 24-trial single-subject design was used, with each condition repeated six times. Most aspects of the participant’s responses in the unanticipated condition did not differ from those of a comparison group of 12 age-matched male controls. Both kinds of meditation produced physiological and facial responses to the startle that were smaller than in the distraction condition. Within meditation conditions, open presence meditation produced smaller physiological and facial responses than focused meditation. These results from a single highly expert meditator indicate that these two kinds of meditation can differentially alter the magnitude of a primitive defensive response. PMID:22506498

  9. 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.

  10. In vivo Ca2+ imaging reveals that decreased dendritic excitability drives startle habituation

    PubMed Central

    Marsden, Kurt C.; Granato, Michael

    2015-01-01

    Summary 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 Ca2+ dynamics in Mauthner neurons, the startle command neurons, during startle habituation in vivo. Using the Ca2+ reporter GCaMP6s we find that the amplitude of Ca2+ signals in the lateral dendrite of the Mauthner neuron determines startle probability and that depression of this dendritic activity rather than downstream inhibition mediates short-term habituation 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. PMID:26655893

  11. 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

  12. 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

  13. 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

  14. Evolution of a Communication System by Sensory Exploitation of Startle Behavior.

    PubMed

    Ter Hofstede, Hannah M; Schöneich, Stefan; Robillard, Tony; Hedwig, Berthold

    2015-12-21

    New communication signals can evolve by sensory exploitation if signaling taps into preexisting sensory biases in receivers [1, 2]. For mate attraction, signals are typically similar to attractive environmental cues like food [3-6], which amplifies their attractiveness to mates, as opposed to aversive stimuli like predator cues. Female field crickets approach the low-frequency calling song of males, whereas they avoid high-frequency sounds like predatory bat calls [7]. In one group of crickets (Eneopterinae: Lebinthini), however, males produce exceptionally high-frequency calling songs in the range of bat calls [8], a surprising signal in the context of mate attraction. We found that female lebinthines, instead of approaching singing males, produce vibrational responses after male calls, and males track the source of vibrations to find females. We also demonstrate that field cricket species closely related to the Lebinthini show an acoustic startle response to high-frequency sounds that generates substrate vibrations similar to those produced by female lebinthine crickets. Therefore, the startle response is the most likely evolutionary origin of the female lebinthine vibrational signal. In field crickets, the brain receives activity from two auditory interneurons; AN1 tuned to male calling song controls positive phonotaxis, and AN2 tuned to high-frequency bat calls triggers negative phonotaxis [9, 10]. In lebinthine crickets, however, we found that auditory ascending neurons are only tuned to high-frequency sounds, and their tuning matches the thresholds for female vibrational signals. Our results demonstrate how sensory exploitation of anti-predator behavior can evolve into a communication system that benefits both senders and receivers. PMID:26687622

  15. Evolution of a Communication System by Sensory Exploitation of Startle Behavior.

    PubMed

    Ter Hofstede, Hannah M; Schöneich, Stefan; Robillard, Tony; Hedwig, Berthold

    2015-12-21

    New communication signals can evolve by sensory exploitation if signaling taps into preexisting sensory biases in receivers [1, 2]. For mate attraction, signals are typically similar to attractive environmental cues like food [3-6], which amplifies their attractiveness to mates, as opposed to aversive stimuli like predator cues. Female field crickets approach the low-frequency calling song of males, whereas they avoid high-frequency sounds like predatory bat calls [7]. In one group of crickets (Eneopterinae: Lebinthini), however, males produce exceptionally high-frequency calling songs in the range of bat calls [8], a surprising signal in the context of mate attraction. We found that female lebinthines, instead of approaching singing males, produce vibrational responses after male calls, and males track the source of vibrations to find females. We also demonstrate that field cricket species closely related to the Lebinthini show an acoustic startle response to high-frequency sounds that generates substrate vibrations similar to those produced by female lebinthine crickets. Therefore, the startle response is the most likely evolutionary origin of the female lebinthine vibrational signal. In field crickets, the brain receives activity from two auditory interneurons; AN1 tuned to male calling song controls positive phonotaxis, and AN2 tuned to high-frequency bat calls triggers negative phonotaxis [9, 10]. In lebinthine crickets, however, we found that auditory ascending neurons are only tuned to high-frequency sounds, and their tuning matches the thresholds for female vibrational signals. Our results demonstrate how sensory exploitation of anti-predator behavior can evolve into a communication system that benefits both senders and receivers.

  16. Effects of REM sleep deprivation on sensorimotor gating and startle habituation in rats: role of social isolation in early development.

    PubMed

    Chang, Hsin-An; Liu, Yia-Ping; Tung, Che-Se; Chang, Chuan-Chia; Tzeng, Nian-Sheng; Huang, San-Yuan

    2014-07-11

    The present study examined the role of rapid eye movement (REM) sleep on sensorimotor gating function in a developmentally rodent model of schizophrenic-spectrum disorders. Startle magnitude, prepulse inhibition (PPI) and startle habituation in an acoustic startle test were measured after 72-h of REM sleep deprivation (REMSD) in 14-week-old rats that were reared in one of the following conditions: control social interaction, 2-week isolation, and continuous isolation, since weaning. The results showed that REMSD significantly inhibited rats' PPI in socially controlled rats, and rats in two isolation groups appeared less sensitive to REMSD. After REMSD, startle habituation was significantly reduced in continuous-isolated rats but not in 2-week-isolated rats. These data indicate that REM sleep is essential for PPI; REMSD inhibits startle habituation in rats with continuous social isolation. In addition, social interaction, in early life or for the whole life, functions differently to the sensorimotor gating.

  17. 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

  18. Immediate and long-lasting effects of chronic stress in the prepubertal age on the startle reflex.

    PubMed

    Maslova, Larissa N; Bulygina, Veta V; Popova, Nina K

    The immediate and long-lasting effects of two models of chronic stress during the prepubertal period of life (21-32 days) on the acoustic startle response (ASR) were studied in outbred Wistar normotensives and rats with inherited stress-induced arterial hypertension (ISIAH) derived from them. Chronic variable stress (CVS) and repeated handling were used as chronic treatment. The obtained data showed a significantly attenuated ASR and a greater magnitude of prepulse inhibition (PPI) in juvenile and adult ISIAH compared to Wistar rats. The immediate effects of prolonged stress on the ASR were genotype-dependent. Young ISIAH rats exposed to both types of prepubertal stimulation had higher ASR than the age-matched controls. No significant stress-induced changes in the ASR were found in young Wistar rats. The long-lasting consequences of prolonged prepubertal stress were similar in the two strains and were determined by the specificity of stress stimulation: chronic handling had no effect on the ASR, while CVS enhanced it. The long-lasting effect of CVS experienced in prepubertal life appears to produce ASR changes similar to those seen in patients with posttraumatic stress disorder (PTSD). The magnitude of PPI increased from early age to adulthood and it was tolerant to environmental influences. The two rat strains did not differ in the rate of short-term habituation to repeated acoustic stimuli, which was unaffected by prepubertal stress. Evidence was obtained indicating that genetic and environmental background in childhood may contribute to the truncation of the startle response.

  19. 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…

  20. 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…

  1. Diminished appetitive startle modulation following targeted inhibition of prefrontal cortex.

    PubMed

    Hurlemann, René; Arndt, Stephan; Schlaepfer, Thomas E; Reul, Juergen; Maier, Wolfgang; Scheele, Dirk

    2015-01-01

    From an evolutionary perspective the startle eye-blink response forms an integral part of the human avoidance behavioral repertoire and is typically diminished by pleasant emotional states. In major depressive disorder (MDD) appetitive motivation is impaired, evident in a reduced interference of positive emotion with the startle response. Given the pivotal role of frontostriatal neurocircuitry in orchestrating appetitive motivation, we hypothesized that inhibitory transcranial magnetic stimulation (TMS) would reduce appetitive neuromodulation in a manner similar to MDD. Based on a pre-TMS functional MRI (fMRI) experiment we selected the left dorsolateral and dorsomedial prefrontal cortices as target regions for subsequent sham-controlled inhibitory theta-burst TMS (TBS) in 40 healthy male volunteers. Consistent with our hypothesis, between-group comparisons revealed a TBS-induced inhibition of appetitive neuromodulation, manifest in a diminished startle response suppression by hedonic stimuli. Collectively, our results suggest that functional integrity of left dorsolateral and dorsomedial prefrontal cortex is critical for mediating a pleasure-induced down-regulation of avoidance responses which may protect the brain from a depressogenic preponderance of defensive stress. PMID:25752944

  2. 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.

  3. Behavioral determination of stimulus pair discrimination of auditory acoustic and electrical stimuli using a classical conditioning and heart-rate approach.

    PubMed

    Morgan, Simeon J; Paolini, Antonio G

    2012-06-06

    Nucleus, guided by the monitoring of neural responses to acoustic stimuli, and the fixation of the electrode into place for chronic use is likewise shown.

  4. The Role of Dopamine in the Context of Aversive Stimuli with Particular Reference to Acoustically Signaled Avoidance Learning

    PubMed Central

    Ilango, Anton; Shumake, Jason; Wetzel, Wolfram; Scheich, Henning; Ohl, Frank W.

    2012-01-01

    Learning from punishment is a powerful means for behavioral adaptation with high relevance for various mechanisms of self-protection. Several studies have explored the contribution of released dopamine (DA) or responses of DA neurons on reward seeking using rewards such as food, water, and sex. Phasic DA signals evoked by rewards or conditioned reward predictors are well documented, as are modulations of these signals by such parameters as reward magnitude, probability, and deviation of actually occurring from expected rewards. Less attention has been paid to DA neuron firing and DA release in response to aversive stimuli, and the prediction and avoidance of punishment. In this review, we first focus on DA changes in response to aversive stimuli as measured by microdialysis and voltammetry followed by the change in electrophysiological signatures by aversive stimuli and fearful events. We subsequently focus on the role of DA and effect of DA manipulations on signaled avoidance learning, which consists of learning the significance of a warning cue through Pavlovian associations and the execution of an instrumental avoidance response. We present a coherent framework utilizing the data on microdialysis, voltammetry, electrophysiological recording, electrical brain stimulation, and behavioral analysis. We end by outlining current gaps in the literature and proposing future directions aimed at incorporating technical and conceptual progress to understand the involvement of reward circuit on punishment based decisions. PMID:23049495

  5. 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.

  6. 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

  7. 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

  8. Degraded expression of learned feedforward control in movements released by startle.

    PubMed

    Wright, Zachary A; Carlsen, Anthony N; MacKinnon, Colum D; Patton, James L

    2015-08-01

    Recent work has shown that preplanned motor programs can be rapidly released via fast conducting pathways using a startling acoustic stimulus. Our question was whether the startle-elicited response might also release a recently learned internal model, which draws on experience to predict and compensate for expected perturbations in a feedforward manner. Our initial investigation using adaptation to robotically produced forces showed some evidence of this, but the results were potentially confounded by co-contraction caused by startle. In this study, we eliminated this confound by asking subjects to make reaching movements in the presence of a visual distortion. Results show that a startle stimulus (1) decreased performance of the recently learned task and (2) reduced after-effect magnitude. Since the recall of learned control was reduced, but not eliminated during startle trials, we suggest that multiple neural centers (cortical and subcortical) are involved in such learning and adaptation. These findings have implications for motor training in areas such as piloting, teleoperation, sports, and rehabilitation.

  9. 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.

  10. Fmrp is required for the establishment of the startle response during the critical period of auditory development.

    PubMed

    Yun, Seong-Wook; Platholi, Jimcy; Flaherty, Maria Sol; Fu, Weimin; Kottmann, Andreas H; Toth, Miklos

    2006-09-19

    Fragile X syndrome, the most common form of inherited mental retardation, is caused by the absence of the FMR-1 gene product FMRP. In addition to the hallmark cognitive defect, other symptoms are also apparent including hyperactivity, seizures and sensory abnormalities including a characteristic increase in sensitivity to auditory, tactile, visual, and olfactory stimuli. Fragile X is a developmental disorder with the first symptoms apparent in the first year of life but little is known about the role of FMRP in developmental processes. The sensory hyperreactivity of fragile X can be reproduced in fmr-1 knockout (KO) mice evident as abnormal audiogenic startle response and increased audiogenic seizure susceptibility. Here, we studied the onset and emergence of the startle deficit in fmr-1 KO mice during development. The startle response was first detectable at the end of the 2nd postnatal week in wild-type mice. The amplitude of startle response showed a substantial increase until the 4th postnatal week followed by a further but moderate increase up to adulthood. Expression of the fmr1 gene was detectable in the startle circuit before the onset and throughout the development of the startle response. Although the onset and amplitude of the startle response were not altered in fmr1 KO mice until the 3rd-4th postnatal week, beyond this age it failed to develop further resulting in an overall response deficit in adult KO mice. This indicates that although Fmrp is dispensable at the initial steps of startle response development, it is necessary for the full development of the response.

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

    PubMed Central

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

    2013-01-01

    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 in context 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 to wild-type (WT) mice, PNMT-KO mice displayed reduced context fear but normal cued fear. Mice exhibited normal memory performance in the short-term version of the novel object recognition task suggesting 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 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 while 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. PMID:23268986

  12. 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.

  13. Prospective Prediction of PTSD Symptoms Using Fear Potentiated Auditory Startle Responses

    PubMed Central

    Pole, Nnamdi; Neylan, Thomas C.; Otte, Christian; Henn-Hasse, Clare; Metzler, Thomas J.; Marmar, Charles R.

    2009-01-01

    Background PTSD has been most consistently associated with exaggerated physiological reactivity to startling sounds when such sounds occur in threatening contexts. There is conflicting evidence about whether startle hyperreactivity is a pre-existing vulnerability factor for PTSD or an acquired result of post-trauma neural sensitization. Until now, there have been no prospective studies of physiological reactivity to startling sounds in threatening contexts as predictors of PTSD symptoms. Methods One hundred and thirty-eight police academy cadets without current psychopathology were exposed to repeated 106 dB startling sounds under increasing (low, medium, or high) threat of mild electric shock while their eyeblink electromyogram, skin conductance, heart rate, and subjective fear responses were recorded. Measures of response habituation were also calculated. Following one year of exposure to police-related trauma, these participants were assessed for PTSD symptom severity. Results After accounting for other baseline variables that were predictive of PTSD symptom severity (age and general psychiatric distress), more severe PTSD symptoms were prospectively and independently predicted by the following startle measures: greater subjective fear under low threat, greater skin conductance under high threat, and slower skin conductance habituation. Conclusions These results imply that hypersensitivity to contextual threat (indexed by greater fear under low threat), elevated sympathetic nervous system reactivity to explicit threat (indexed by larger responses under high threat), and failure to adapt to repeated aversive stimuli (evidenced by slower habituation) are all unique pre-existing vulnerability factors for greater PTSD symptom severity following traumatic stress exposure. These measures may eventually prove useful for preventing PTSD. PMID:18722593

  14. Corticotropin-releasing factor (CRF) and α 2 adrenergic receptors mediate heroin withdrawal-potentiated startle in rats.

    PubMed

    Park, Paula E; Vendruscolo, Leandro F; Schlosburg, Joel E; Edwards, Scott; Schulteis, Gery; Koob, George F

    2013-09-01

    Anxiety is one of the early symptoms of opioid withdrawal and contributes to continued drug use and relapse. The acoustic startle response (ASR) is a component of anxiety that has been shown to increase during opioid withdrawal in both humans and animals. We investigated the role of corticotropin-releasing factor (CRF) and norepinephrine (NE), two key mediators of the brain stress system, on acute heroin withdrawal-potentiated ASR. Rats injected with heroin (2 mg/kg s.c.) displayed an increased ASR when tested 4 h after heroin treatment. A similar increase in ASR was found in rats 10-20 h into withdrawal from extended access (12 h) to i.v. heroin self-administration, a model that captures several aspects of heroin addiction in humans. Both the α 2 adrenergic receptor agonist clonidine (10 μg/kg s.c.) and CRF1 receptor antagonist N,N-bis(2-methoxyethyl)-3-(4-methoxy-2-methylphenyl)-2,5-dimethyl-pyrazolo[1,5-a] pyrimidin-7-amine (MPZP; 20 mg/kg s.c.) blocked heroin withdrawal-potentiated startle. To investigate the relationship between CRF1 and α 2 adrenergic receptors in the potentiation of the ASR, we tested the effect of MPZP on yohimbine (1.25 mg/kg s.c.)-potentiated startle and clonidine on CRF (2 μg i.c.v.)-potentiated startle. Clonidine blocked CRF-potentiated startle, whereas MPZP partially attenuated but did not reverse yohimbine-potentiated startle, suggesting that CRF may drive NE release to potentiate startle. These results suggest that CRF1 and α 2 receptors play an important role in the heightened anxiety-like behaviour observed during acute withdrawal from heroin, possibly via CRF inducing the release of NE in stress-related brain regions.

  15. Synaptic depression and short-term habituation are located in the sensory part of the mammalian startle pathway

    PubMed Central

    Simons-Weidenmaier, Nadine S; Weber, Maruschka; Plappert, Claudia F; Pilz, Peter KD; Schmid, Susanne

    2006-01-01

    Background Short-term habituation of the startle response represents an elementary form of learning in mammals. The underlying mechanism is located within the primary startle pathway, presumably at sensory synapses on giant neurons in the caudal pontine reticular nucleus (PnC). Short trains of action potentials in sensory afferent fibers induce depression of synaptic responses in PnC giant neurons, a phenomenon that has been proposed to be the cellular correlate for short-term habituation. We address here the question whether both this synaptic depression and the short-term habituation of the startle response are localized at the presynaptic terminals of sensory afferents. If this is confirmed, it would imply that these processes take place prior to multimodal signal integration, rather than occurring at postsynaptic sites on PnC giant neurons that directly drive motor neurons. Results Patch-clamp recordings in vitro were combined with behavioral experiments; synaptic depression was specific for the input pathway stimulated and did not affect signals elicited by other sensory afferents. Concordant with this, short-term habituation of the acoustic startle response in behavioral experiments did not influence tactile startle response amplitudes and vice versa. Further electrophysiological analysis showed that the passive properties of the postsynaptic neuron were unchanged but revealed some alterations in short-term plasticity during depression. Moreover, depression was induced only by trains of presynaptic action potentials and not by single pulses. There was no evidence for transmitter receptor desensitization. In summary, the data indicates that the synaptic depression mechanism is located presynaptically. Conclusion Our electrophysiological and behavioral data strongly indicate that synaptic depression in the PnC as well as short-term habituation are located in the sensory part of the startle pathway, namely at the axon terminals of sensory afferents in the Pn

  16. 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.

  17. 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.

  18. Affect-Modulated Startle: Interactive Influence of Catechol-O-Methyltransferase Val158Met Genotype and Childhood Trauma

    PubMed Central

    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. PMID:22745815

  19. 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. PMID:26841102

  20. 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.

  1. Meclizine enhancement of sensorimotor gating in healthy male subjects with high startle responses and low prepulse inhibition.

    PubMed

    Larrauri, José A; Kelley, Lisalynn D; Jenkins, Mason R; Westman, Eric C; Schmajuk, Nestor A; Rosenthal, M Zachary; Levin, Edward D

    2014-02-01

    Histamine H1 receptor systems have been shown in animal studies to have important roles in the reversal of sensorimotor gating deficits, as measured by prepulse inhibition (PPI). H1-antagonist treatment attenuates the PPI impairments caused by either blockade of NMDA glutamate receptors or facilitation of dopamine transmission. The current experiment brought the investigation of H1 effects on sensorimotor gating to human studies. The effects of the histamine H1 antagonist meclizine on the startle response and PPI were investigated in healthy male subjects with high baseline startle responses and low PPI levels. Meclizine was administered to participants (n=24) using a within-subjects design with each participant receiving 0, 12.5, and 25 mg of meclizine in a counterbalanced order. Startle response, PPI, heart rate response, galvanic skin response, and changes in self-report ratings of alertness levels and affective states (arousal and valence) were assessed. When compared with the control (placebo) condition, the two doses of meclizine analyzed (12.5 and 25 mg) produced significant increases in PPI without affecting the magnitude of the startle response or other physiological variables. Meclizine also caused a significant increase in overall self-reported arousal levels, which was not correlated with the observed increase in PPI. These results are in agreement with previous reports in the animal literature and suggest that H1 antagonists may have beneficial effects in the treatment of subjects with compromised sensorimotor gating and enhanced motor responses to sensory stimuli. PMID:24045586

  2. Meclizine Enhancement of Sensorimotor Gating in Healthy Male Subjects with High Startle Responses and Low Prepulse Inhibition

    PubMed Central

    Larrauri, José A; Kelley, Lisalynn D; Jenkins, Mason R; Westman, Eric C; Schmajuk, Nestor A; Rosenthal, M Zachary; Levin, Edward D

    2014-01-01

    Histamine H1 receptor systems have been shown in animal studies to have important roles in the reversal of sensorimotor gating deficits, as measured by prepulse inhibition (PPI). H1-antagonist treatment attenuates the PPI impairments caused by either blockade of NMDA glutamate receptors or facilitation of dopamine transmission. The current experiment brought the investigation of H1 effects on sensorimotor gating to human studies. The effects of the histamine H1 antagonist meclizine on the startle response and PPI were investigated in healthy male subjects with high baseline startle responses and low PPI levels. Meclizine was administered to participants (n=24) using a within-subjects design with each participant receiving 0, 12.5, and 25 mg of meclizine in a counterbalanced order. Startle response, PPI, heart rate response, galvanic skin response, and changes in self-report ratings of alertness levels and affective states (arousal and valence) were assessed. When compared with the control (placebo) condition, the two doses of meclizine analyzed (12.5 and 25 mg) produced significant increases in PPI without affecting the magnitude of the startle response or other physiological variables. Meclizine also caused a significant increase in overall self-reported arousal levels, which was not correlated with the observed increase in PPI. These results are in agreement with previous reports in the animal literature and suggest that H1 antagonists may have beneficial effects in the treatment of subjects with compromised sensorimotor gating and enhanced motor responses to sensory stimuli. PMID:24045586

  3. Persistence of pain induced by startle and forehead cooling after sympathetic blockade in patients with complex regional pain syndrome

    PubMed Central

    Drummond, P; Finch, P

    2004-01-01

    Background: Stimuli arousing sympathetic activity can increase ratings of clinical pain in patients with complex regional pain syndrome (CRPS). Objective: To determine whether the increase in pain is mediated by peripheral sympathetic activity. Methods: The effect of sympathetic ganglion blockade on pain evoked by a startle stimulus and cooling the forehead was investigated in 36 CRPS patients. Results: Loss of vasoconstrictor reflexes and warming of the limb indicated that sympathetic blockade was effective in 26 cases. Before sympathetic blockade, pain increased in 12 of these 26 patients when they were startled. Pain increased in seven of the 12 patients and in another five cases when their forehead was cooled. As expected, pain that increased during sympathetic arousal generally subsided in patients with signs of sympathetic blockade. However, pain still increased in three of 12 of patients after the startle stimulus and in six of 12 of patients during forehead cooling, despite indisputable sympathetic blockade. Conclusions: These findings suggest that stimuli arousing sympathetic activity act by a central process to exacerbate pain in some patients, independent of the peripheral sympathetic nervous system. This may account for the lack of effect of peripheral sympathetic blockade on pain in some CRPS patients. PMID:14707316

  4. 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

  5. Headphone localization of speech stimuli

    NASA Technical Reports Server (NTRS)

    Begault, Durand R.; Wenzel, Elizabeth M.

    1991-01-01

    Recently, three dimensional acoustic display systems have been developed that synthesize virtual sound sources over headphones based on filtering by Head-Related Transfer Functions (HRTFs), the direction-dependent spectral changes caused primarily by the outer ears. Here, 11 inexperienced subjects judged the apparent spatial location of headphone-presented speech stimuli filtered with non-individualized HRTFs. About half of the subjects 'pulled' their judgements toward either the median or the lateral-vertical planes, and estimates were almost always elevated. Individual differences were pronounced for the distance judgements; 15 to 46 percent of stimuli were heard inside the head with the shortest estimates near the median plane. The results infer that most listeners can obtain useful azimuth information from speech stimuli filtered by nonindividualized RTFs. Measurements of localization error and reversal rates are comparable with a previous study that used broadband noise stimuli.

  6. 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.

  7. The impact of early neglect on defensive and appetitive physiology during the pubertal transition: a study of startle and postauricular reflexes.

    PubMed

    Quevedo, Karina; Johnson, Anna E; Loman, Michelle M; Lafavor, Theresa; Moua, Bao; Gunnar, Megan R

    2015-04-01

    This study tested the effect of early neglect on defensive and appetitive physiology during puberty. 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. 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. 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.

  8. Prediction of drilling site-specific interaction of industrial acoustic stimuli and endangered whales: Beaufort Sea (1985). Final report, July 1985-March 1986

    SciTech Connect

    Miles, P.R.; Malme, C.I.; Shepard, G.W.; Richardson, W.J.; Bird, J.E.

    1986-10-01

    Research was performed during the first year (1985) of the two-year project investigating potential responsiveness of bowhead and gray whales to underwater sounds associated with offshore oil-drilling sites in the Alaskan Beaufort Sea. The underwater acoustic environment and sound propagation characteristics of five offshore sites were determined. Estimates of industrial noise levels versus distance from those sites are provided. LGL Ltd. (bowhead) and BBN (gray whale) jointly present zones of responsiveness of these whales to typical underwater sounds (drillship, dredge, tugs, drilling at gravel island). An annotated bibliography regarding the potential effects of offshore industrial noise on bowhead whales in the Beaufort Sea is included.

  9. Prepulse inhibition predicts working memory performance whilst startle habituation predicts spatial reference memory retention in C57BL/6 mice.

    PubMed

    Singer, Philipp; Hauser, Jonas; Llano Lopez, Luis; Peleg-Raibstein, Daria; Feldon, Joram; Gargiulo, Pascual A; Yee, Benjamin K

    2013-04-01

    Prepulse inhibition (PPI) of the acoustic startle reflex refers to the attenuation of the startle response to an intense pulse stimulus when it is shortly preceded by a weak non-startling prepulse stimulus. It is a well-established high-throughput translational measure of pre-attentive sensory gating, and its impairment is detected in several neuropsychiatric diseases including schizophrenia. It has been hypothesized that PPI might be associated with, or predictive of, cognitive deficiency in such diseases, and therefore provide an efficient assay for screening drugs with potential pro-cognitive efficacy. Free from any predetermined disease model, the present study evaluated in a homogeneous cohort of inbred C57BL/6 mice the presence of a statistical link between PPI expression and cognitive performance. Performance indices in a spatial reference memory test and a working memory test conducted in the Morris water maze, and contextual fear conditioning were correlated against pre-existing baseline PPI expression. A specific correlative link between working memory and PPI induced by weak (but not strong) prepulse was revealed. In addition, a correlation between habituation of the startle reflex and reference memory was identified for the first time: a stronger overt habituation effect was associated with superior spatial search accuracy. The PPI paradigm thus provides two independent predictors of dissociable cognitive traits in normal C57BL/6 mice; and they might serve as potential markers for high-throughput evaluation of potential cognitive enhancers, especially in the context of schizophrenia where deficits in startle habituation and PPI co-exist.

  10. Startle provoked epileptic seizures:features in 19 patients.

    PubMed Central

    Manford, M R; Fish, D R; Shorvon, S D

    1996-01-01

    OBJECTIVES--To define the clinical characteristics of a group of patients with startle provoked epileptic seizures (SPES). METHODS--Nineteen patients were identified during the course of a larger study of clinical seizure patterns. A witnessed seizure account was obtained in all patients; interictal EEG in 18, video-EEG-telemetry in eight, CT in 18, and high resolution MRI in eight. RESULTS--The onset of SPES was in childhood or adolescence in 14 of 19 patients. It was preceded by exclusively spontaneous seizures in nine patients and SPES had been replaced by exclusively spontaneous seizures in two patients. Sudden noise was the main triggering stimulus and somatosensory and visual stimuli were also effective in some patients. The clinical seizure pattern involved asymmetric tonic posturing in 16 of 19 patients. Focal neurological signs were present in nine patients, mental retardation in six, and 10 were clinically normal. Ictal scalp EEG showed a clear seizure discharge in only one patient with a tonic seizure pattern; over the lateral frontal electrodes contralateral to the posturing limbs. Brain CT showed a porencephalic cyst in three patients, focal frontal atrophy in one, and generalised atrophy in one. Brain MRI was undertaken in five normal subjects and three neurologically impaired patients, six with normal CT. It showed a porencephalic cyst in one patient. In six patients, there were dysplastic lesions. They affected the lateral premotor cortex in three patients and the perisylvian cortex in three patients, one with bilateral perisylvian abnormality. CONCLUSIONS--SPES are more frequent than is generally appreciated. They may be transient and occur relatively commonly without fixed deficit, by contrast with previous reports. The imaging abnormalities identified in those without diffuse cerebral damage suggest that SPES are often due to occult congenital lesions and that the lateral premotor and perisylvian cortices are important in this phenomenon. Images

  11. Individual Differences in Fear Potentiated Startle in Behaviorally Inhibited Children

    PubMed Central

    Barker, Tyson V.; Reeb-Sutherland, Bethany; Fox, Nathan A.

    2014-01-01

    Behavioral inhibition (BI) is a temperament characterized during early childhood by increased fearfulness to novelty, social reticence to unfamiliar peers, and heightened risk for the development of anxiety. Heightened startle responses to safety cues have been found among behaviorally inhibited adolescents who have an anxiety disorder suggesting that this measure may serve as a biomarker for the development of anxiety amongst this risk population. However, it is unknown if these aberrant startle patterns emerge prior to the manifestation of anxiety in this temperament group. The current study examined potentiated startle in 7-year-old children characterized with BI early in life. High behaviorally inhibited children displayed increased startle magnitude to safety cues, particularly during the first half of the task, and faster startle responses compared to low behaviorally inhibited children. These findings suggest that aberrant startle responses are apparent in behaviorally inhibited children during early childhood prior to the onset of a disorder and may serve as a possible endophenotype for the development of anxiety PMID:23341151

  12. The Role of Neuropeptide Y in the Expression and Extinction of Fear-Potentiated Startle

    PubMed Central

    Gutman, Alisa R.; Yang, Yong; Ressler, Kerry J.; Davis, Michael

    2008-01-01

    Neuropeptides are a promising target for novel treatments for anxiety and other psychiatric disorders and neuropeptide Y (NPY) has emerged as a key component of anxiolytic circuits in the brain. For this reason, we have evaluated the role of NPY in the expression and extinction of conditioned fear. We found that intracerebroventricular (i.c.v.) administration of NPY inhibits both baseline acoustic startle and the expression of fear-potentiated startle. Infusion of NPY (10 pmol/side) into the basolateral, but not the medial, nucleus of the amygdala reproduced the i.c.v. effect. Central administration of NPY (10 μg) also enhanced within-session extinction of fear-potentiated startle. This finding, coupled with the growing body of literature correlating NPY with resilience in humans, led us to the hypothesis that NPY may enhance the extinction of conditioned fear. When NPY (10 μg) is administered i.c.v. prior to extinction training, extinction retention for both the contextual and cued components of conditioned fear is enhanced when tested 48 hours later off drug. Additionally, we found that intra-basolateral amygdala administration of the NPY Y1 receptor antagonist BIBO 3304 (200 pmol/side) prior to extinction training led to a profound deficit in extinction retention. This is the first evidence that NPY facilitates and an NPY antagonist blocks the extinction of conditioned fear. We believe that the role of NPY in the extinction of conditioned fear may, at least in part, explain the mechanism underlying the association between NPY and psychobiological resilience in humans. PMID:19036961

  13. 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.

  14. The effect of choice on the physiology of emotion: An affective startle modulation study

    PubMed Central

    Genevsky, Alexander; Gard, David E.

    2014-01-01

    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. PMID:22285891

  15. AX+, BX- discrimination learning in the fear-potentiated startle paradigm: possible relevance to inhibitory fear learning in extinction.

    PubMed

    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.

  16. 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

    Davis, Michael; Walker, David L

    2014-11-01

    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.

  17. Acoustic Similarity and Dichotic Listening.

    ERIC Educational Resources Information Center

    Benson, Peter

    1978-01-01

    An experiment tests conjectures that right ear advantage (REA) has an auditory origin in competition or interference between acoustically similar stimuli and that feature-sharing effect (FSE) has its origin in assignment of features of phonetically similar stimuli. No effect on the REA for acoustic similarity, and a clear effect of acoustic…

  18. Effects of age, but not sex, on elevated startle during withdrawal from acute morphine in adolescent and adult rats.

    PubMed

    Radke, Anna K; Gewirtz, Jonathan C; Carroll, Marilyn E

    2015-08-01

    Investigations into animal models of drug withdrawal have largely found that emotional signs of withdrawal (e.g. anxiety, anhedonia, and aversion) in adolescents are experienced earlier and less severely than in their adult counterparts. The majority of these reports have examined withdrawal from ethanol or nicotine. To expand our knowledge about the emotional withdrawal state in adolescent rats, we used potentiation of the acoustic startle reflex after an acute dose of morphine (10 mg/kg, subcutaneously) as a measure of opiate withdrawal. Startle was measured at four time points after morphine injection (2, 3, 4, and 5 h) in 28-day-old and 90-day-old male and female rats. The results of this experiment revealed that peak potentiation of the startle reflex occurred at 3 h in the adolescent rats and at 5 h in the adult rats, and that the magnitude of withdrawal was larger in the adults. No sex differences were observed. Overall, these results affirm that, similar to withdrawal from ethanol and nicotine, opiate withdrawal signs are less severe in adolescent than in adult rats.

  19. Effects of age, but not sex, on elevated startle during withdrawal from acute morphine in adolescent and adult rats

    PubMed Central

    Radke, Anna K.; Gewirtz, Jonathan C.; Carroll, Marilyn E.

    2015-01-01

    Investigations into animal models of drug withdrawal have largely found that emotional signs of withdrawal (e.g., anxiety, anhedonia, and aversion) in adolescents are experienced earlier and less severely than in their adult counterparts. The majority of these reports have examined withdrawal from ethanol or nicotine. In order to expand our knowledge about the emotional withdrawal state in adolescent rats, we used potentiation of the acoustic startle reflex after an acute dose of morphine (10 mg/kg, s.c.) as a measure of opioid withdrawal. Startle was measured at four time points after morphine injection (2, 3, 4, and 5 h) in 28 and 90 day old male and female rats. The results of this experiment revealed that peak potentiation of the startle reflex occurred at 3 h in the adolescent rats and at 5 h in the adult rats, and that the magnitude of withdrawal was larger in the adults. No sex differences were observed. Overall, these results affirm that, similar to withdrawal from ethanol and nicotine, opiate withdrawal signs are less severe in adolescent than in adult rats. PMID:26154436

  20. Do infants find snakes aversive? Infants' physiological responses to "fear-relevant" stimuli.

    PubMed

    Thrasher, Cat; LoBue, Vanessa

    2016-02-01

    In the current research, we sought to measure infants' physiological responses to snakes-one of the world's most widely feared stimuli-to examine whether they find snakes aversive or merely attention grabbing. Using a similar method to DeLoache and LoBue (Developmental Science, 2009, Vol. 12, pp. 201-207), 6- to 9-month-olds watched a series of multimodal (both auditory and visual) stimuli: a video of a snake (fear-relevant) or an elephant (non-fear-relevant) paired with either a fearful or happy auditory track. We measured physiological responses to the pairs of stimuli, including startle magnitude, latency to startle, and heart rate. Results suggest that snakes capture infants' attention; infants showed the fastest startle responses and lowest average heart rate to the snakes, especially when paired with a fearful voice. Unexpectedly, they also showed significantly reduced startle magnitude during this same snake video plus fearful voice combination. The results are discussed with respect to theoretical perspectives on fear acquisition.

  1. 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

  2. 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…

  3. 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 ...

  4. Forward acoustic masking enhances the auditory brainstem response in a diotic, but not dichotic, paradigm in salicylate-induced tinnitus.

    PubMed

    Liu, Xiao-Peng; Chen, Lin

    2015-05-01

    We recently reported that forward acoustic masking can enhance the auditory brainstem response (ABR) in rats treated with a high dose of sodium salicylate (NaSal), a tinnitus inducer, when tested in open acoustic field (Liu and Chen, 2012, Brain Research 1485, 88-94). In the present study, we first replicated this experiment in closed acoustic field under two conditions: (1) the forward masker and the probe were presented to both ears (diotic paradigm); (2) the forward masker was presented to one ear and the probe to the other ear (dichotic paradigm). We found that only when the stimuli were presented by using the diotic, rather than the dichotic, paradigm could forward acoustic masking enhance the ABR in the rat treated with NaSal (300 mg/kg). The enhancement was obvious for ABR waves II and IV, but not for wave I, indicating a central origin. The enhancement occurred at the high frequencies (16, 24, 32 kHz) at which the animals demonstrated a tinnitus-like behavior as revealed by using the gap prepulse inhibition of acoustic startle paradigm. We then administered vigabatrin, a GABA transaminase inhibitor, in the animals to suppress NaSal-induced tinnitus. The vigabatrin treatment successfully prevented forward acoustic masking from enhancing the ABR. These findings demonstrate that the observed enhancement of ABRs by forward acoustic masking originates in the central auditory pathway ipsilateral to the stimulated ear. We propose that the enhancement is closely associated with NaSal-induced tinnitus. PMID:25668125

  5. 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

  6. Visual Complexity Attenuates Emotional Processing in Psychopathy: Implications for Fear-Potentiated Startle Deficits

    PubMed Central

    Sadeh, Naomi; Verona, Edelyn

    2012-01-01

    A long-standing debate is the extent to which psychopathy is characterized by a fundamental deficit in attention or emotion. We tested the hypothesis that the interplay of emotional and attentional systems is critical for understanding processing deficits in psychopathy. Sixty-three offenders were assessed using the Psychopathy Checklist: Screening Version. Event-related brain potentials (ERPs) and fear-potentiated startle (FPS) were collected while participants viewed pictures selected to disentangle an existing confound between perceptual complexity and emotional content in the pictures typically used to study fear deficits in psychopathy. As predicted, picture complexity moderated emotional processing deficits. Specifically, the affective-interpersonal features of psychopathy were associated with greater allocation of attentional resources to processing emotional stimuli at initial perception (visual N1) but only when picture stimuli were visually-complex. Despite this, results for the late positive potential indicated that emotional pictures were less attentionally engaging and held less motivational significance for individuals high in affective-interpersonal traits. This deficient negative emotional processing was observed later in their reduced defensive fear reactivity (FPS) to high-complexity unpleasant pictures. In contrast, the impulsive-antisocial features of psychopathy were associated with decreased sensitivity to picture complexity (visual N1) and unrelated to emotional processing as assessed by ERP and FPS. These findings are the first to demonstrate that picture complexity moderates FPS deficits and implicate the interplay of attention and emotional systems as deficient in psychopathy. PMID:22187225

  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. Facial Expression Recognition, Fear Conditioning, and Startle Modulation in Female Subjects with Conduct Disorder

    PubMed Central

    Fairchild, Graeme; Stobbe, Yvette; van Goozen, Stephanie H.M.; Calder, Andrew J.; Goodyer, Ian M.

    2010-01-01

    Background Recent behavioral and psychophysiological studies have provided converging evidence for emotional dysfunction in conduct disorder (CD). Most of these studies focused on male subjects and little is known about emotional processing in female subjects with CD. Our primary aim was to characterize explicit and implicit aspects of emotion function to determine whether deficits in these processes are present in girls with CD. Methods Female adolescents with CD (n = 25) and control subjects with no history of severe antisocial behavior and no current psychiatric disorder (n = 30) completed tasks measuring facial expression and facial identity recognition, differential autonomic conditioning, and affective modulation of the startle reflex by picture valence. Results Compared with control subjects, participants with CD showed impaired recognition of anger and disgust but no differences in facial identity recognition. Impaired sadness recognition was observed in CD participants high in psychopathic traits relative to those lower in psychopathic traits. Participants with CD displayed reduced skin conductance responses to an aversive unconditioned stimulus and impaired autonomic discrimination between the conditioned stimuli, indicating impaired fear conditioning. Participants with CD also showed reduced startle magnitudes across picture valence types, but there were no significant group differences in the pattern of affective modulation. Conclusions Adolescent female subjects with CD exhibited deficits in explicit and implicit tests of emotion function and reduced autonomic responsiveness across different output systems. There were, however, no differences in emotional reactivity. These findings suggest that emotional recognition and learning are impaired in female subjects with CD, consistent with results previously obtained in male subjects with CD. PMID:20447616

  9. 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.

  10. Modulation of the startle reflex by pleasant and unpleasant music.

    PubMed

    Roy, Mathieu; Mailhot, Jean-Philippe; Gosselin, Nathalie; Paquette, Sébastien; Peretz, Isabelle

    2009-01-01

    The issue of emotional feelings to music is the object of a classic debate in music psychology. Emotivists argue that emotions are really felt in response to music, whereas cognitivists believe that music is only representative of emotions. Psychophysiological recordings of emotional feelings to music might help to resolve the debate, but past studies have failed to show clear and consistent differences between musical excerpts of different emotional valence. Here, we compared the effects of pleasant and unpleasant musical excerpts on the startle eye blink reflex and associated body markers (such as the corrugator and zygomatic activity, skin conductance level and heart rate). The startle eye blink amplitude was larger and its latency was shorter during unpleasant compared with pleasant music, suggesting that the defensive emotional system was indeed modulated by music. Corrugator activity was also enhanced during unpleasant music, whereas skin conductance level was higher for pleasant excerpts. The startle reflex was the response that contributed the most in distinguishing pleasant and unpleasant music. Taken together, these results provide strong evidence that emotions were felt in response to music, supporting the emotivist stance. PMID:18725255

  11. Modulation of the startle reflex by pleasant and unpleasant music.

    PubMed

    Roy, Mathieu; Mailhot, Jean-Philippe; Gosselin, Nathalie; Paquette, Sébastien; Peretz, Isabelle

    2009-01-01

    The issue of emotional feelings to music is the object of a classic debate in music psychology. Emotivists argue that emotions are really felt in response to music, whereas cognitivists believe that music is only representative of emotions. Psychophysiological recordings of emotional feelings to music might help to resolve the debate, but past studies have failed to show clear and consistent differences between musical excerpts of different emotional valence. Here, we compared the effects of pleasant and unpleasant musical excerpts on the startle eye blink reflex and associated body markers (such as the corrugator and zygomatic activity, skin conductance level and heart rate). The startle eye blink amplitude was larger and its latency was shorter during unpleasant compared with pleasant music, suggesting that the defensive emotional system was indeed modulated by music. Corrugator activity was also enhanced during unpleasant music, whereas skin conductance level was higher for pleasant excerpts. The startle reflex was the response that contributed the most in distinguishing pleasant and unpleasant music. Taken together, these results provide strong evidence that emotions were felt in response to music, supporting the emotivist stance.

  12. Muscle group dependent responses to stimuli in a grasshopper model for tonic immobility

    PubMed Central

    Miriyala, Ashwin; Dutta-Gupta, Aparna; Joseph, Joby

    2013-01-01

    Summary Tonic Immobility (TI) is a prolonged immobile condition exhibited by a variety of animals when exposed to certain stimuli, and is thought to be associated with a specific state of arousal. In our study, we characterize this state by using the reliably inducible TI state of the grasshopper (Hieroglyphus banian) and by monitoring abdominal pulsations and body movements in response to visual and auditory stimuli. These pulsations are present during the TI and ‘awake’, standing states, but not in the CO2 anesthetized state. In response to the stimuli, animals exhibited a suppression in pulsation and a startle response. The suppression of pulsation lasted longer than the duration of stimulus application. During TI, the suppression of pulsation does not habituate over time, whereas the startle response does. In response to the translating visual stimulus, the pulsations are suppressed at a certain phase independent of the time of stimulus application. Thus, we describe TI in Hieroglyphus banian as a state more similar to an ‘awake’ state than to an anesthetized state. During TI, the circuitry to the muscle outputs controlling the abdomen pulsation and the startle response are, at least in some part, different. The central pattern generators that maintain the abdomen pulsation receive inputs from visual and auditory pathways. PMID:24244858

  13. Affective Modulation of the Startle Response among Children at High and Low Risk for Anxiety Disorders

    PubMed Central

    Kujawa, Autumn; Glenn, Catherine R.; Hajcak, Greg; Klein, Daniel N.

    2016-01-01

    Background Identifying early markers of risk for anxiety disorders in children may aid in understanding underlying mechanisms and informing prevention efforts. Affective modulation of the startle response indexes sensitivity to pleasant and unpleasant environmental contexts and has been shown to relate to anxiety, yet the extent to which abnormalities in affect-modulated startle reflect vulnerability for anxiety disorders in children has yet to be examined. The current study assessed the effects of parental psychopathology on affective modulation of startle in offspring. Methods Nine-year-old children (N=144) with no history of anxiety or depressive disorders completed a passive picture viewing task in which eye blink startle responses were measured during the presentation of pleasant, neutral, and unpleasant images. Results Maternal anxiety was associated with distinct patterns of affective modulation of startle in offspring, such that children with maternal histories of anxiety showed potentiation of the startle response while viewing unpleasant images, but not attenuation during pleasant images, whereas children with no maternal history of anxiety exhibited attenuation of the startle response during pleasant images, but did not exhibit unpleasant potentiation—even when controlling for child symptoms of anxiety and depression. No effects of maternal depression or paternal psychopathology were observed. Conclusions These findings suggest that both enhanced startle responses in unpleasant conditions and failure to inhibit startle responses in pleasant conditions may reflect early-emerging vulnerabilities that contribute to the later development of anxiety disorders. PMID:25913397

  14. 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

  15. 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. PMID:27401960

  16. 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.

  17. Genetic and environmental influences on emotion-modulated startle reflex: a twin study.

    PubMed

    Anokhin, Andrey P; Golosheykin, Simon; Heath, Andrew C

    2007-01-01

    Emotion-modulated startle reflex is an important indicator of traitlike differences in affective processing implicated in the biological basis of personality and psychopathology. This study examined heritability of startle modulation by affective pictures in 66 pairs of monozygotic and 57 pairs of dizygotic female twins. Consistent with previous studies, startle magnitude was significantly influenced by emotional valence of the picture (positive < neutral < negative). Absolute response magnitude showed high heritability in all three valence conditions (59-61%); however, there were no significant genetic influences on the amount of startle modulation. Thus, our data do not support the hypothesis that emotion-modulated startle can serve as an indicator of genetically transmitted individual differences in affective processing.

  18. Startle response and prepulse inhibition modulation by positive- and negative-induced affect.

    PubMed

    De la Casa, Luis Gonzalo; Mena, Auxiliadora; Puentes, Andrea

    2014-02-01

    The startle response, a set of reflex behaviours intended to prepare the organism to face a potentially threatening stimulus, can be modulated by several factors as, for example, changes in affective state, or previous presentation of a weak stimulus (a phenomenon termed Pre-Pulse Inhibition [PPI]). In this paper we analyse whether the induction of positive or negative affective states in the participants modulates the startle response and the PPI phenomenon. The results revealed a decrease of the startle response and an increase of the PPI effect when registered while the participants were exposed to pleasant images (Experiment 1), and an increase of the startle response and of the PPI effect when they were exposed to a video-clip of unpleasant content (Experiment 2). These data are interpreted considering that changes in affective states correlate with changes in the startle reflex intensity, but changes in PPI might be the result of an attentional process.

  19. 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

  20. Startle response and prepulse inhibition modulation by positive- and negative-induced affect.

    PubMed

    De la Casa, Luis Gonzalo; Mena, Auxiliadora; Puentes, Andrea

    2014-02-01

    The startle response, a set of reflex behaviours intended to prepare the organism to face a potentially threatening stimulus, can be modulated by several factors as, for example, changes in affective state, or previous presentation of a weak stimulus (a phenomenon termed Pre-Pulse Inhibition [PPI]). In this paper we analyse whether the induction of positive or negative affective states in the participants modulates the startle response and the PPI phenomenon. The results revealed a decrease of the startle response and an increase of the PPI effect when registered while the participants were exposed to pleasant images (Experiment 1), and an increase of the startle response and of the PPI effect when they were exposed to a video-clip of unpleasant content (Experiment 2). These data are interpreted considering that changes in affective states correlate with changes in the startle reflex intensity, but changes in PPI might be the result of an attentional process. PMID:24188916

  1. 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.

  2. Defensive eye-blink startle responses in a human experimental model of anxiety.

    PubMed

    Pinkney, Verity; Wickens, Robin; Bamford, Susan; Baldwin, David S; Garner, Matthew

    2014-09-01

    Inhalation of low concentrations of carbon dioxide (CO2) triggers anxious behaviours in rodents via chemosensors in the amygdala, and increases anxiety, autonomic arousal and hypervigilance in healthy humans. However, it is not known whether CO2 inhalation modulates defensive behaviours coordinated by this network in humans. We examined the effect of 7.5% CO2 challenge on the defensive eye-blink startle response. A total of 27 healthy volunteers completed an affective startle task during inhalation of 7.5% CO2 and air. The magnitude and latency of startle eye-blinks were recorded whilst participants viewed aversive and neutral pictures. We found that 7.5% CO2 increased state anxiety and raised concurrent measures of skin conductance and heart rate (HR). CO2 challenge did not increase startle magnitude, but slowed the onset of startle eye-blinks. The effect of CO2 challenge on HR covaried with its effects on both subjective anxiety and startle latency. Our findings are discussed with reference to startle profiles during conditions of interoceptive threat, increased cognitive load and in populations characterised by anxiety, compared with acute fear and panic. PMID:24899597

  3. Heart rate, startle response, and intrusive trauma memories

    PubMed Central

    Chou, Chia-Ying; Marca, Roberto La; Steptoe, Andrew; Brewin, Chris R

    2014-01-01

    The current study adopted the trauma film paradigm to examine potential moderators affecting heart rate (HR) as an indicator of peritraumatic psychological states and as a predictor of intrusive memories. We replicated previous findings that perifilm HR decreases predicted the development of intrusive images and further showed this effect to be specific to images rather than thoughts, and to detail rather than gist recognition memory. Moreover, a group of individuals showing both an atypical sudden reduction in HR after a startle stimulus and higher trait dissociation was identified. Only among these individuals was lower perifilm HR found to indicate higher state dissociation, fear, and anxiety, along with reduced vividness of intrusions. The current findings emphasize how peritraumatic physiological responses relate to emotional reactions and intrusive memory. The moderating role of individual difference in stress defense style was highlighted. PMID:24397333

  4. 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.

  5. Startle Modification and P50 Gating in Schizophrenia Patients and Controls: Russian Population.

    PubMed

    Storozheva, Zinaida I; Kirenskaya, Anna V; Novototsky-Vlasov, Vladimir Y; Telesheva, Klavdia Y; Pletnikov, Mikhail

    2016-01-01

    Prepulse modification of the acoustic startle response (ASR) and P50 gating are potential neurophysiological endophenotypes of schizophrenia and may be used in the construction of valid clinical biomarkers. Such approach requires a large amount of data obtained in the representative samples from different gender, socio-typological and ethnic groups, replicating studies using the similar protocols and meta-analyses. This is a replication study of ASR and the first study of P50 suppression in Russian patients with schizophrenia (n = 28) and healthy controls (n = 25). ASR and P50 were estimated according to standard protocols. Patients exhibited increased baseline ASR latency (d = 0.35, p = .026) and reduced prepulse inhibition (PPI) at 60 ms interval (d = 0.39, p = .003) and 120 ms interval (d = 0.37, p = .005) relative to controls. In the P50 test patients displayed greater S2 response amplitude (d = 0.24, p = .036) and deficit of P50 suppression (d = 0.43, p = .001). No correlations of PPI and P50 suppression were found in both groups. Only in controls prepulse ASR facilitation (at 2500 ms interval) positively correlated with P50 suppression (r = -.514, p = .013). In patients PPI displayed significant correlations with Difficulty in abstract thinking (N5: r = -.49, p = .005) and Hallucination (P3: r = .40, p = .036) PANSS scales. Logistic regression showed that the combination of PPI and P50 suppression could serve as a diagnostic predictor. Obtained results demonstrated that both PPI and P50 could be regarded as potential schizophrenia biomarkers in Russian population. PMID:26936103

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. Prenatal IV Nicotine Exposure Produces a Sex Difference in Sensorimotor Gating of the Auditory Startle Reflex in Adult Rats

    PubMed Central

    Lacy, Ryan T.; Mactutus, Charles F.; Harrod, Steven B.

    2011-01-01

    Maternal smoking during pregnancy is associated with auditory processing deficits in children; these effects have been confirmed with animal models of continuous high-dose prenatal nicotine exposure. The present experiments utilized a novel, low-dose, intermittent, intravenous (IV) gestational nicotine exposure model to investigate potential deficits on the preattentive process of sensorimotor gating, as indexed by prepulse inhibition (PPI), in preweanling and adult rat offspring. Pregnant dams received bolus IV injections of nicotine (0.05 mg/kg/injection) 3x/day on gestational days 8–21. Auditory and tactile stimulus modalities were probed with tone and air puff prepulse stimuli, respectively. These prepulse stimuli preceded a 100 dB(A) startle tone by six different interstimulus intervals (ISIs; 0, 8, 40, 80, 120, 4000 ms) to define a curve of response inhibition. The magnitude of PPI increased with age, from 59 to 81% inhibition. Preweanlings (PND 14 and 18) and adults (PND 75) gestationally exposed to nicotine exhibited altered startle responding relative to controls, but the nature of the deficit became more localized at later ages. The entire curve of response inhibition in preweanlings exposed to prenatal nicotine (PND 14) was shifted up relative to controls, and notably, did not interact with prepulse stimulus modality, suggesting a generalized increased sensorimotor responsiveness as a function of prenatal nicotine. At PND 18, a shift in the response curve across all ISIs was again noted, but varied as a function of prepulse stimulus modality; the increased sensorimotor responsiveness was specific to the auditory, but not tactile, sensory modality. In adulthood, male and females animals prenatally exposed to nicotine were differentially sensitive to modulation by the ISIs, relative to control male and female animals. Specifically, despite robust PPI, adult females exposed to gestational nicotine were relatively insensitive to changes in ISI from 8–120

  11. Worrying affects associative fear learning: a startle fear conditioning study.

    PubMed

    Gazendam, Femke J; Kindt, Merel

    2012-01-01

    A valuable experimental model for the pathogenesis of anxiety disorders is that they originate from a learned association between an intrinsically non-aversive event (Conditioned Stimulus, CS) and an anticipated disaster (Unconditioned Stimulus, UCS). Most anxiety disorders, however, do not evolve from a traumatic experience. Insights from neuroscience show that memory can be modified post-learning, which may elucidate how pathological fear can develop after relatively mild aversive events. Worrying--a process frequently observed in anxiety disorders--is a potential candidate to strengthen the formation of fear memory after learning. Here we tested in a discriminative fear conditioning procedure whether worry strengthens associative fear memory. Participants were randomly assigned to either a Worry (n = 23) or Control condition (n = 25). After fear acquisition, the participants in the Worry condition processed six worrisome questions regarding the personal aversive consequences of an electric stimulus (UCS), whereas the Control condition received difficult but neutral questions. Subsequently, extinction, reinstatement and re-extinction of fear were tested. Conditioned responding was measured by fear-potentiated startle (FPS), skin conductance (SCR) and UCS expectancy ratings. Our main results demonstrate that worrying resulted in increased fear responses (FPS) to both the feared stimulus (CS(+)) and the originally safe stimulus (CS(-)), whereas FPS remained unchanged in the Control condition. In addition, worrying impaired both extinction and re-extinction learning of UCS expectancy. The implication of our findings is that they show how worry may contribute to the development of anxiety disorders by affecting associative fear learning.

  12. 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...

  13. 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…

  14. 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.

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

    PubMed Central

    Bradford, Daniel E.; Starr, Mark J.; Shackman, Alexander J.

    2015-01-01

    Abstract 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. PMID:26372120

  16. Wind turbine acoustic standards

    NASA Technical Reports Server (NTRS)

    Stephens, D. G.; Shepherd, K. P.; Grosveld, F.

    1981-01-01

    A program is being conducted to develop noise standards for wind turbines which minimize annoyance and which can be used to design specifications. The approach consists of presenting wind turbine noise stimuli to test subjects in a laboratory listening chamber. The responses of the subjects are recorded for a range of stimuli which encompass the designs, operating conditions, and ambient noise levels of current and future installations. Results to date have established the threshold of detectability for a range of impulsive stimuli of the type associated with blade/tower wake interactions. The status of the ongoing psychoacoustic tests, the subjective data, and the approach to the development of acoustic criteria/standards are described.

  17. Phylo- and ontogenetic fears and the expectation of danger: differences between spider- and flight-phobic subjects in cognitive and physiological responses to disorder-specific stimuli.

    PubMed

    Mühlberger, Andreas; Wiedemann, Georg; Herrmann, Martin J; Pauli, Paul

    2006-08-01

    To compare specific phobias with an assumed phylogenetic or ontogenetic origin in responses to fear-relevant (FR) stimuli, 17 spider- and 17 flight-phobic participants were exposed to pictures of spiders, flight accidents, or mushrooms randomly followed by either a startling noise or nothing else. While both groups showed a disorder-specific expectancy bias, only spider-phobic participants exhibited a disorder-specific covariation bias. Spider-phobic participants also showed enhanced skin conductance responses (SCRs), event-related brain potentials (ERPs), and startle responses triggered by disorder-specific FR pictures while flight-phobic participants showed only disorder-specific enhanced SCRs. In sum, our direct comparison between ontogenetic and phylogenetic phobias revealed that the former is characterized by biased and enhanced responses triggered by disorder-specific FR stimuli presumably based on a biological preparedness.

  18. 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.

  19. 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.

  20. Tracking the startle response of guppies Poecilia reticulata in three dimensions.

    PubMed

    Vanesyan, A; Rodd, F H; Ryu, W S

    2015-10-01

    A three-dimensional analysis of startle behaviours of guppies Poecilia reticulata, in dyads or alone, from two populations that show distinct differences in shoaling behaviour was performed. During the first few seconds after a startling stimulus, changes in behaviour, which could be critical if an individual is to survive a predatory attack, and the interactions between pairs of P. reticulata were examined. The enhanced social interactions immediately after the stimulus, as a proxy for shoaling behaviour, and their dissipation were quantified. Social (individuals tested in dyads) v. asocial (tested alone) responses to the startling stimulus were also compared. The three-dimensional reconstruction, from a two-camera, high-frame-rate tracking system allowed for the tracking of the individuals' speed and speed recovery and, for P. reticulata in dyads, interindividual distance and orientation. For the dyads from the high-predation population, the closer the individuals were to each other, the more likely they were to be parallel, but no correlation was found for the low-predation P. reticulata. The startle response of P. reticulata comprised the following sequence: freezing, darting and skittering and recovery to pre-stimulus swimming behaviour. Upon repeated encounters with the stimulus, a reduced shoaling and startle response was observed, although the rate of reduction was faster in P. reticulata from the high-predation population than those from the low-predation population. The results are discussed in light of what is known about the anti-predator behaviour of this species.

  1. Tracking the startle response of guppies Poecilia reticulata in three dimensions.

    PubMed

    Vanesyan, A; Rodd, F H; Ryu, W S

    2015-10-01

    A three-dimensional analysis of startle behaviours of guppies Poecilia reticulata, in dyads or alone, from two populations that show distinct differences in shoaling behaviour was performed. During the first few seconds after a startling stimulus, changes in behaviour, which could be critical if an individual is to survive a predatory attack, and the interactions between pairs of P. reticulata were examined. The enhanced social interactions immediately after the stimulus, as a proxy for shoaling behaviour, and their dissipation were quantified. Social (individuals tested in dyads) v. asocial (tested alone) responses to the startling stimulus were also compared. The three-dimensional reconstruction, from a two-camera, high-frame-rate tracking system allowed for the tracking of the individuals' speed and speed recovery and, for P. reticulata in dyads, interindividual distance and orientation. For the dyads from the high-predation population, the closer the individuals were to each other, the more likely they were to be parallel, but no correlation was found for the low-predation P. reticulata. The startle response of P. reticulata comprised the following sequence: freezing, darting and skittering and recovery to pre-stimulus swimming behaviour. Upon repeated encounters with the stimulus, a reduced shoaling and startle response was observed, although the rate of reduction was faster in P. reticulata from the high-predation population than those from the low-predation population. The results are discussed in light of what is known about the anti-predator behaviour of this species. PMID:26376772

  2. Association between violent behaviour and impaired prepulse inhibition of the startle response in antisocial personality disorder and schizophrenia.

    PubMed

    Kumari, Veena; Das, Mrigen; Hodgins, Sheilagh; Zachariah, Elizabeth; Barkataki, Ian; Howlett, Michael; Sharma, Tonmoy

    2005-03-01

    Violent behaviour has a strong association with antisocial personality disorder (APD) and schizophrenia. Although developments in the understanding of socio-environmental factors associated with violence should not be ignored, advances in prevention and treatment of violent behaviour would benefit by improved understanding of its neurobiological and cognitive basis. The authors, therefore, investigated prepulse inhibition (PPI) of the startle response in APD and schizophrenia in relation to a history of serious violence. The neural substrates of PPI, especially the hippocampus, amygdala, thalamus and basal ganglia, are implicated in violence as well as in APD and schizophrenia. The study included four groups: (i) patients with APD and a history of violence, (ii) patients with schizophrenia and a history of violence, (iii) patients with schizophrenia without a history of violence, and (iv) healthy subjects with no history of violence or a mental disorder. All subjects were assessed identically on acoustic PPI. Compared to healthy subjects, significantly reduced PPI occurred in APD, violent schizophrenia and non-violent schizophrenia patients. Although PPI did not significantly differentiate the three clinical groups, high ratings of violence were modestly associated with reduced PPI across the entire study sample. Violent patients with impulsive and premeditated violence showed comparable PPI. The association between violent behaviour and impaired PPI suggests that neural structures and functions underlying PPI are implicated in (inhibition of) violence.

  3. Accommodation for flickering stimuli.

    PubMed

    Owens, D A; Wolfe, J M

    1985-01-01

    A laser optometer was used to measure accommodative responses of three observers for sinusoidal gratings presented in Maxwellian view at optical distances ranging from 0 to 4 diopters. Contrast of the stimuli was modulated spatially at 1.0, 4.2 and 6.5 cycles deg.-1 (cpd), and temporally at six frequencies ranging from 3.0 to 40 Hz. Accommodation was consistently more accurate for the 4.2 cpd than for either the 1.0 or 6.5 cpd gratings. Furthermore, accommodative responsiveness for the 4.2 cpd was not affected by temporal modulation, while that for the other spatial frequencies improved monotonically as a function of temporal frequency. These results reinforce earlier reports that accommodation is most responsive for contrast of intermediate spatial frequencies and they indicate that stimulus flicker generally degrades accommodation for spatial contrast.

  4. Isolation rearing of mice induces deficits in prepulse inhibition of the startle response.

    PubMed

    Varty, Geoffrey B; Powell, Susan B; Lehmann-Masten, Virginia; Buell, Mahalah R; Geyer, Mark A

    2006-04-25

    Male 129T2 and C57BL/6J mice were housed either in groups of three (socials) or singly (isolates) at weaning. Six and seven weeks later, prepulse inhibition (PPI), startle reactivity, and locomotor activity (LMA) were measured. Isolation-reared mice of both strains exhibited PPI deficits compared to socially reared controls in at least one of the two PPI test sessions. Isolation rearing had no effect on startle reactivity or habituation and only 129T2 isolates exhibited increased LMA. Isolation rearing induced locomotor hyperactivity and PPI deficits in mice and may be an effective developmental manipulation to use in combination with studies of genetically altered mice.

  5. Modulation of the startle reflex across time by unpleasant pictures distinguishes dysphoric from non-dysphoric women.

    PubMed

    Taubitz, Lauren E; Robinson, Jordan S; Larson, Christine L

    2013-02-01

    While several investigators have examined differences in affective startle modulation between individuals with and without Major Depressive Disorder, fewer researchers have evaluated the time course of this response, particularly in dysphoric individuals. The purpose of this study was to evaluate emotion modulation of the startle reflex during and after the presentation of affective pictures in dysphoric and non-dysphoric women. Dysphoric subjects showed attenuated startle for unpleasant compared to neutral pictures 1.5s post-stimulus onset relative to non-dysphoric subjects and potentiated startle for unpleasant compared to neutral pictures 3s post-stimulus offset. These findings extend the literature on the time course of affective startle modulation in dysphoria, and mirror results of studies in which other psychophysiological responses were examined in this population with regard to negative emotion.

  6. 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…

  7. Effects of the hallucinogen psilocybin on habituation and prepulse inhibition of the startle reflex in humans.

    PubMed

    Gouzoulis-Mayfrank, E; Heekeren, K; Thelen, B; Lindenblatt, H; Kovar, K A; Sass, H; Geyer, M A

    1998-11-01

    Schizophrenic patients exhibit deficits in indices of sensorimotor gating, such as habituation and prepulse inhibition (PPI) of the startle reflex. Hallucinogenic drug-induced states are putative models for the early and acute stages of schizophrenic and schizophrenia-spectrum disorders. Hallucinogenic drugs have been shown to disrupt PPI and/or retard habituation of the startle reflex in animal models of schizophrenia, consistent with the view of hallucinogen-induced states as 'model psychoses'. We evaluated the effects of the hallucinogen psilocybin on PPI and habituation of the startle reflex in a double-blind, placebo-controlled human study with 12 healthy subjects. In contrast to animal studies, in our small human sample, psilocybin increased PPI, while having no clear effect on habituation (n = 6). These findings must be considered preliminary because several factors, including dose regimens and experimental parameters, may influence the results of studies on startle plasticity. Further investigations both with psychotic patients in different stages of the disease and with human and animal models of schizophrenia are needed in order to explore the effects of hallucinogens on sensorimotor gating and the relationship between information processing in hallucinogenic drug-induced states and the naturally occurring psychoses.

  8. Acoustical standards in engineering acoustics

    NASA Astrophysics Data System (ADS)

    Burkhard, Mahlon D.

    2001-05-01

    The Engineering Acoustics Technical Committee is concerned with the evolution and improvement of acoustical techniques and apparatus, and with the promotion of new applications of acoustics. As cited in the Membership Directory and Handbook (2002), the interest areas include transducers and arrays; underwater acoustic systems; acoustical instrumentation and monitoring; applied sonics, promotion of useful effects, information gathering and transmission; audio engineering; acoustic holography and acoustic imaging; acoustic signal processing (equipment and techniques); and ultrasound and infrasound. Evident connections between engineering and standards are needs for calibration, consistent terminology, uniform presentation of data, reference levels, or design targets for product development. Thus for the acoustical engineer standards are both a tool for practices, for communication, and for comparison of his efforts with those of others. Development of many standards depends on knowledge of the way products are put together for the market place and acoustical engineers provide important input to the development of standards. Acoustical engineers and members of the Engineering Acoustics arm of the Society both benefit from and contribute to the Acoustical Standards of the Acoustical Society.

  9. 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.

  10. 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. PMID:18032886

  11. 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.

  12. 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.

  13. Acoustic Neuroma

    MedlinePlus

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

  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. 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.

  16. [Stimuli-sensitive polymer systems].

    PubMed

    Le Cerf, D

    2014-11-01

    The polymers can be found in different forms in solution (particles, capsules, pseudo-micelles, hydrogels…) or on surface with important prospects in many field applications. These polymer systems are particularly very good candidates to entrap, transport and deliver an active substance in biomedical applications however with many limitations on control of release of a given target. The stimuli-sensitive polymers, also called smart or environmentally sensitive polymers, present physical or chemical changes under the action of small variations of an external stimulus. This signal acts as a stimulus which causes the change of conformation and/or solvation of the macromolecular chains by modifying their various interactions. The stimuli are classified into two broad categories: physical or external stimuli: temperature, mechanical stress, light, magnetic and electric fields; chemical and biochemical or internal stimuli: pH, ionic strength, chemical molecule (glucose, redox) or biochemical (enzymes, antigens…). The use of stimuli-sensitive pathway is widely used in the literature to enhance or trigger the release of an active compound. In this paper, we present the different stimuli addressing the theoretical aspects, polymers corresponding to these stimuli. Some examples illustrate these systems for the controlled release of active compounds.

  17. Timing and classifying brief acoustic stimuli by songbirds and humans.

    PubMed

    Weisman, R; Brownlie, L; Olthof, A; Njegovan, M; Sturdy, C; Mewhort, D

    1999-04-01

    The durations of animals' brief vocalizations provide conspecifics with important recognition cues. In the present experiments, zebra finches and humans (trained musicians) were rewarded for responding after S+ (standard) auditory signals from 56 to 663 ms and not for responding after shorter or longer S- (comparison) durations from 10 to 3684 ms. With either a single standard (Experiment 1) or multiple standards (Experiment 2), both zebra finches and humans timed brief signals to about the same level of accuracy. The results were in qualitative agreement with predictions from scalar timing theory and its connectionist implementation in both experiments. The connectionist model provides a good quantitative account of temporal gradients with a single standard (Experiment 1) but not with multiple standards (Experiment 2). PMID:10331915

  18. Children's Acquisition of Phonology: The Learning of Acoustic Stimuli?

    ERIC Educational Resources Information Center

    Locke, John L.

    This paper takes issue with the position that children's phoneme acquisition schedule is dictated primarily by auditory perceptual factors and suggests the alternative position that ease of production accounts for age of acquisition. It is felt that perceptual theory cannot adequately explain phonological development, e.g. three-year-olds produce…

  19. Crowding of biological motion stimuli.

    PubMed

    Ikeda, Hanako; Watanabe, Katsumi; Cavanagh, Patrick

    2013-01-01

    It is difficult to identify a target in the peripheral visual field when it is flanked by distractors. In the present study, we investigated this "crowding" effect for biological motion stimuli. Three walking biological motion stimuli were presented horizontally in the periphery with various distances between them, and observers reported the walking direction of the central figure. When the inter-walker distance was small, discriminating the direction became difficult. Moreover, the reported direction for the central target was not simply noisier, but reflected a degree of pooling of the three directions from the target and two flankers. However, when the two flanking distractors were scrambled walking biological motion stimuli, crowding was not seen. This result suggests that the crowding of biological motion stimuli occurs at a high-level of motion perception.

  20. 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.

  1. 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

  2. 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.

  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. PMID:25447471

  4. Topological Acoustics

    NASA Astrophysics Data System (ADS)

    Yang, Zhaoju; Gao, Fei; Shi, Xihang; Lin, Xiao; Gao, Zhen; Chong, Yidong; Zhang, Baile

    2015-03-01

    The manipulation of acoustic wave propagation in fluids has numerous applications, including some in everyday life. Acoustic technologies frequently develop in tandem with optics, using shared concepts such as waveguiding and metamedia. It is thus noteworthy that an entirely novel class of electromagnetic waves, known as "topological edge states," has recently been demonstrated. These are inspired by the electronic edge states occurring in topological insulators, and possess a striking and technologically promising property: the ability to travel in a single direction along a surface without backscattering, regardless of the existence of defects or disorder. Here, we develop an analogous theory of topological fluid acoustics, and propose a scheme for realizing topological edge states in an acoustic structure containing circulating fluids. The phenomenon of disorder-free one-way sound propagation, which does not occur in ordinary acoustic devices, may have novel applications for acoustic isolators, modulators, and transducers.

  5. Topological acoustics.

    PubMed

    Yang, Zhaoju; Gao, Fei; Shi, Xihang; Lin, Xiao; Gao, Zhen; Chong, Yidong; Zhang, Baile

    2015-03-20

    The manipulation of acoustic wave propagation in fluids has numerous applications, including some in everyday life. Acoustic technologies frequently develop in tandem with optics, using shared concepts such as waveguiding and metamedia. It is thus noteworthy that an entirely novel class of electromagnetic waves, known as "topological edge states," has recently been demonstrated. These are inspired by the electronic edge states occurring in topological insulators, and possess a striking and technologically promising property: the ability to travel in a single direction along a surface without backscattering, regardless of the existence of defects or disorder. Here, we develop an analogous theory of topological fluid acoustics, and propose a scheme for realizing topological edge states in an acoustic structure containing circulating fluids. The phenomenon of disorder-free one-way sound propagation, which does not occur in ordinary acoustic devices, may have novel applications for acoustic isolators, modulators, and transducers.

  6. No Impact of Deep Brain Stimulation on Fear-Potentiated Startle in Obsessive–Compulsive Disorder

    PubMed Central

    Baas, Johanna M. P.; Klumpers, Floris; Mantione, Mariska H.; Figee, Martijn; Vulink, Nienke C.; Schuurman, P. Richard; Mazaheri, Ali; Denys, Damiaan

    2014-01-01

    Deep brain stimulation (DBS) of the ventral internal capsule is effective in treating therapy refractory obsessive–compulsive disorder (OCD). Given the close proximity of the stimulation site to the stria terminalis (BNST), we hypothesized that the striking decrease in anxiety symptoms following DBS could be the result of the modulation of contextual anxiety. However, the effect of DBS in this region on contextual anxiety is as of yet unknown. Thus, the current study investigated the effect of DBS on contextual anxiety in an experimental threat of shock paradigm. Eight patients with DBS treatment for severe OCD were tested in a double-blind crossover design with randomly assigned 2-week periods of active and sham stimulation. DBS resulted in significant decrease of obsessive–compulsive symptoms, anxiety, and depression. However, even though the threat manipulation resulted in a clear context-potentiated startle effect, none of the parameters derived from the startle recordings was modulated by the DBS. This suggests that DBS in the ventral internal capsule is effective in treating anxiety symptoms of OCD without modulating the startle circuitry. We hypothesize that the anxiety symptoms present in OCD are likely distinct from the pathological brain circuits in defensive states of other anxiety disorders. PMID:25249953

  7. No impact of deep brain stimulation on fear-potentiated startle in obsessive-compulsive disorder.

    PubMed

    Baas, Johanna M P; Klumpers, Floris; Mantione, Mariska H; Figee, Martijn; Vulink, Nienke C; Schuurman, P Richard; Mazaheri, Ali; Denys, Damiaan

    2014-01-01

    Deep brain stimulation (DBS) of the ventral internal capsule is effective in treating therapy refractory obsessive-compulsive disorder (OCD). Given the close proximity of the stimulation site to the stria terminalis (BNST), we hypothesized that the striking decrease in anxiety symptoms following DBS could be the result of the modulation of contextual anxiety. However, the effect of DBS in this region on contextual anxiety is as of yet unknown. Thus, the current study investigated the effect of DBS on contextual anxiety in an experimental threat of shock paradigm. Eight patients with DBS treatment for severe OCD were tested in a double-blind crossover design with randomly assigned 2-week periods of active and sham stimulation. DBS resulted in significant decrease of obsessive-compulsive symptoms, anxiety, and depression. However, even though the threat manipulation resulted in a clear context-potentiated startle effect, none of the parameters derived from the startle recordings was modulated by the DBS. This suggests that DBS in the ventral internal capsule is effective in treating anxiety symptoms of OCD without modulating the startle circuitry. We hypothesize that the anxiety symptoms present in OCD are likely distinct from the pathological brain circuits in defensive states of other anxiety disorders. PMID:25249953

  8. Risk for eating disorders modulates startle-responses to body words.

    PubMed

    Herbert, Cornelia; Kübler, Andrea; Vögele, Claus

    2013-01-01

    Body image disturbances are core symptoms of eating disorders (EDs). Recent evidence suggests that changes in body image may occur prior to ED onset and are not restricted to in-vivo exposure (e.g. mirror image), but also evident during presentation of abstract cues such as body shape and weight-related words. In the present study startle modulation, heart rate and subjective evaluations were examined during reading of body words and neutral words in 41 student female volunteers screened for risk of EDs. The aim was to determine if responses to body words are attributable to a general negativity bias regardless of ED risk or if activated, ED relevant negative body schemas facilitate priming of defensive responses. Heart rate and word ratings differed between body words and neutral words in the whole female sample, supporting a general processing bias for body weight and shape-related concepts in young women regardless of ED risk. Startle modulation was specifically related to eating disorder symptoms, as was indicated by significant positive correlations with self-reported body dissatisfaction. These results emphasize the relevance of examining body schema representations as a function of ED risk across different levels of responding. Peripheral-physiological measures such as the startle reflex could possibly be used as predictors of females' risk for developing EDs in the future.

  9. Reflex Modification by Acoustic Signals in Newborn Infants and in Adults.

    ERIC Educational Resources Information Center

    Hoffman, Howard S.; And Others

    1985-01-01

    Five experiments using identical reflex modification procedures on neonates and adults suggest developmental differences in processing auditory stimuli. Neonates failed to exhibit reflex inhibition by either prior acoustic or tactile stimuli. Adults exhibited robust reflex inhibition to these same stimuli. Developmental processes implied by these…

  10. How do people order stimuli?

    PubMed

    Kemp, Simon; Grace, Randolph C

    2014-08-01

    People may find it easier to construct an order after first representing stimuli on a scale or categorizing them, particularly when the number of stimuli to be ordered is large or when some of them must be remembered. Five experiments tested this hypothesis. In two of these experiments (1 and 3), we asked participants to rank line lengths or to rank photographs by artistic value. The participants provided evidence of how they performed these tasks, and this evidence indicated that they often made use of some preliminary representation--either a metric or a categorization. Two further experiments (2 and 4) indicated that people rarely produced rankings when given a choice of assessment measures for either the length of lines or the artistic value of photographs. In Experiment 5, when the number of lines was larger or lines were only visible one at a time, participants were faster at estimating line lengths as a percentage of the card covered than at rank ordering the lengths. Overall, the results indicate that ordering stimuli is not an easy or natural process when the number of stimuli is large or when the stimuli are not all perceptible at once. An implication is that the psychological measures available to individuals are not likely to be purely ordinal when many of the elements being measured must be recalled.

  11. Stimuli-responsive polymer films.

    PubMed

    Zhai, Lei

    2013-09-01

    Stimuli-responsive polymer films undergo interesting structural and property changes upon external stimuli. Their applications have extended from smart coatings to controlled drug release, smart windows, self-repair and other fields. This tutorial review summarizes non-covalent bonding, reversible reactions and responsive molecules that have played important roles in creating stimuli-responsive systems, and presents the recent development of three types of responsive polymer systems: layer-by-layer polymer multilayer films, polymer brushes, and self-repairing polymer films, with a discussion of their response mechanism. Future research efforts include comprehensive understanding of the response mechanism, producing polymer systems with controlled response properties regarding single or multiple external signals, combining polymer film fabrication with nanotechnology, improving the stability of polymer films on substrates, and evaluating the toxicity of the degradation products. PMID:23749141

  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 metafluids.

    PubMed

    Norris, Andrew N

    2009-02-01

    Acoustic metafluids are defined as the class of fluids that allow one domain of fluid to acoustically mimic another, as exemplified by acoustic cloaks. It is shown that the most general class of acoustic metafluids are materials with anisotropic inertia and the elastic properties of what are known as pentamode materials. The derivation uses the notion of finite deformation to define the transformation of one region to another. The main result is found by considering energy density in the original and transformed regions. Properties of acoustic metafluids are discussed, and general conditions are found which ensure that the mapped fluid has isotropic inertia, which potentially opens up the possibility of achieving broadband cloaking. PMID:19206861

  14. Interactions of auditory and visual stimuli in space and time.

    PubMed

    Recanzone, Gregg H

    2009-12-01

    The nervous system has evolved to transduce different types of environmental energy independently, for example light energy is transduced by the retina whereas sound energy is transduced by the cochlea. However, the neural processing of this energy is necessarily combined, resulting in a unified percept of a real-world object or event. These percepts can be modified in the laboratory, resulting in illusions that can be used to probe how multisensory integration occurs. This paper reviews studies that have utilized such illusory percepts in order to better understand the integration of auditory and visual signals in primates. Results from human psychophysical experiments where visual stimuli alter the perception of acoustic space (the ventriloquism effect) are discussed, as are experiments probing the underlying cortical mechanisms of this integration. Similar psychophysical experiments where auditory stimuli alter the perception of visual temporal processing are also described. PMID:19393306

  15. Stimuli, Reinforcers, and Private Events

    ERIC Educational Resources Information Center

    Nevin, John A.

    2008-01-01

    Radical behaviorism considers private events to be a part of ongoing observable behavior and to share the properties of public events. Although private events cannot be measured directly, their roles in overt action can be inferred from mathematical models that relate private responses to external stimuli and reinforcers according to the same…

  16. 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.

  17. Context and explicit threat cue modulation of the startle reflex: Preliminary evidence of distinctions between adolescents with principal fear disorders versus distress disorders

    PubMed Central

    Waters, Allison M.; Nazarian, Maria; Mineka, Susan; Zinbarg, Richard E.; Griffith, James W.; Naliboff, Bruce; Ornitz, Edward M.; Craske, Michelle G.

    2014-01-01

    Anxiety and depression are prevalent, impairing disorders. High comorbidity has raised questions about how to define and classify them. Structural models emphasise distinctions between “fear” and “distress” disorders while other initiatives propose they be defined by neurobiological indicators that cut across disorders. This study examined startle reflex (SR) modulation in adolescents with principal fear disorders (specific phobia; social phobia) (n = 20), distress disorders (unipolar depressive disorders, dysthymia, generalized anxiety disorder; post-traumatic stress disorder) (n = 9), and controls (n = 29) during (a) baseline conditions, (b) threat context conditions (presence of contraction pads over the biceps muscle), and (c) an explicit threat cue paradigm involving phases that signalled safety from aversive stimuli (early and late stages of safe phases; early stages of danger phases) and phases that signalled immediate danger of an aversive stimulus (late stages of danger phases). Adolescents with principal fear disorders showed larger SRs than other groups throughout safe phases and early stages of danger phases. SRs did not differ between groups during late danger phases. Adolescents with principal distress disorders showed attenuated SRs during baseline and context conditions compared to other groups. Preliminary findings support initiatives to redefine emotional disorders based on neurobiological functioning. PMID:24679992

  18. Evidence for impaired sound intensity processing during prepulse inhibition of the startle response in a rodent developmental disruption model of schizophrenia

    PubMed Central

    Ewing, Samuel G.; Grace, Anthony A.

    2013-01-01

    A number of studies have implicated disruptions in prepulse inhibition (PPI) of the startle response in both schizophrenia patients and animal models of this disorder. These disruptions are believed to reflect deficits in sensorimotor gating and are ascribed to aberrant filtering of sensory inputs leading to sensory overload and enhanced “noise” in neural structures. Here we examined auditory evoked potentials in a rodent model of schizophrenia (MAM-GD17) during an auditory PPI paradigm to better understand this phenomenon. MAM rats exhibited reductions in specific components of auditory evoked potentials in the orbtiofrontal cortex and an abolition of the graded response to stimuli of differing intensities indicating deficient intensity processing in the orbitofrontal cortex. These data indicate that aberrant sensory information processing, rather than being attributable to enhanced noise in neural structures, may be better attributed to diminished evoked amplitudes resulting in a reduction in the “signal-to-noise” ratio. Therefore, the ability for sensory input to modulate the ongoing background activity may be severely disrupted in schizophrenia yielding an internal state which is insufficiently responsive to external input. PMID:23932574

  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. Acoustic trauma

    MedlinePlus

    Acoustic trauma is a common cause of sensory hearing loss . Damage to the hearing mechanisms within the inner ... Symptoms include: Partial hearing loss that most often involves ... The hearing loss may slowly get worse. Noises, ringing in ...

  1. Acoustic Neuroma

    MedlinePlus

    ... slow growing tumor which arise primarily from the vestibular portion of the VIII cranial nerve and lie ... you have a "brain tumor" called acoustic neuroma (vestibular schwannoma). You think you are the only one ...

  2. Underwater Acoustics.

    ERIC Educational Resources Information Center

    Creasey, D. J.

    1981-01-01

    Summarizes the history of underwater acoustics and describes related research studies and teaching activities at the University of Birmingham (England). Also includes research studies on transducer design and mathematical techniques. (SK)

  3. 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.

  4. Dendritic Distributions of Dopamine D1 Receptors in the Rat Nucleus Accumbens are Synergistically Affected by Startle-Evoking Auditory Stimulation and Apomorphine

    PubMed Central

    Hara, Yuko; Pickel, Virginia M.

    2007-01-01

    Prepulse inhibition of the startle response to auditory stimulation (AS) is a measure of sensorimotor gating that is disrupted by the dopamine D1/D2 receptor agonist, apomorphine. The apomorphine effect on prepulse inhibition is ascribed in part to altered synaptic transmission in the limbic-associated shell and motor-associated core subregions of the nucleus accumbens (Acb). We used electron microscopic immunolabeling of dopamine D1 receptors (D1Rs) in the Acb shell and core to test the hypothesis that region-specific redistribution of D1Rs is a short-term consequence of AS and/or apomorphine administration. Thus, comparisons were made in the Acb of rats sacrificed one hour after receiving a single subcutaneous injection of vehicle (VEH) or apomorphine (APO) alone or in combination with startle-evoking AS (VEH+AS, APO+AS). In both regions of all animals, the D1R immunoreactivity was present in somata and large, as well as small, presumably more distal dendrites and dendritic spines. In the Acb shell, compared with the VEH+AS group, the APO+AS group had more spines containing D1R immunogold particles, and these particles were more prevalent on the plasma membranes. This suggests movement of D1Rs from distal dendrites to the plasma membrane of dendritic spines. Small- and medium-sized dendrites also showed a higher plasmalemmal density of D1R in the Acb shell of the APO+AS group compared with the APO group. In the Acb core, the APO+AS group had a higher plasmalemmal density of D1R in medium-sized dendrites compared with the APO or VEH+AS group. Also in the Acb core, D1R-labeled dendrites were significantly smaller in the VEH+AS group compared to all other groups. These results suggest that alerting stimuli and apomorphine synergistically affect distributions of D1R in Acb shell and core. Thus adaptations in D1R distribution may contribute to sensorimotor gating deficits that can be induced acutely by apomorphine or develop over time in schizophrenia. PMID:17490822

  5. Aversive Startle Potentiation and Fear Pathology: Mediating Role of Threat Sensitivity and Moderating Impact of Depression

    PubMed Central

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

    2015-01-01

    Enhanced startle 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. PMID:25448265

  6. Alcohol selectively reduces anxiety but not fear: Startle response during unpredictable vs. predictable threat

    PubMed Central

    Moberg, Christine A.; Curtin, John J.

    2009-01-01

    Recent theory and empirical research has suggested that fear and anxiety are distinct processes with separable neurobiological substrates. Furthermore, a laboratory procedure has been developed to manipulate fear vs. anxiety independently via administration of predictable or unpredictable electric shock, respectively. Benzodiazepines appear to selectively reduce anxiety but not fear in this procedure. The primary aim of this experiment was to determine if alcohol produced a similar selective reduction in anxiety. Intoxicated (target blood alcohol concentration of 0.08%) and non-intoxicated participants viewed a series of colored squares separated by variable inter-trial intervals (ITI) in three conditions. In the predictable shock condition, shocks were administered contingently during every square. In the unpredictable shock condition, shocks were administered non-contingently during both squares and ITIs. In the no-shock condition, no shocks were administered at any time. Alcohol significantly reduced startle potentiation during cues signaling unpredictable but not predictable shock, consistent with the thesis that alcohol selectively reduces anxiety but not fear. In addition, alcohol’s effect on startle potentiation during unpredictable shock was mediated by vigilance. This anxiolytic effect may clarify the nature of alcohol’s reinforcing effects in social and problem drinkers. PMID:19413408

  7. Startle Response to Unpredictable Threat in Comorbid Panic Disorder and Alcohol Dependence

    PubMed Central

    Gorka, Stephanie M.; Nelson, Brady D.; Shankman, Stewart A.

    2013-01-01

    Background Although the adverse consequences of comorbid panic disorder (PD) and alcohol dependence (AD) are well-established, relatively little is known about the mechanisms underlying their co-occurrence. Several researchers have postulated that alcohol's ability to dampen response to unpredictable threat may be an important motivational factor in comorbid PD and AD. To date, no research has examined these processes using a clinical sample and it is unclear whether individuals with PD and AD evidence different reactivity to unpredictable threat relative to individuals with PD-only. Methods The aim of the current study was to examine differences in aversive responding during predictable and unpredictable threat-of-shock in three groups of individuals with: 1) current PD and remitted AD (PD and AD), 2) current PD but no lifetime diagnosis of AD (PD-only), and 3) no lifetime diagnoses of PD or AD (controls). Aversive responding was assessed using a well-established electromyography (EMG) startle paradigm. Results Results indicated that PD and AD individuals evidenced greater startle potentiation during unpredictable (but not predictable) threat relative to controls and PD-only individuals (who did not differ). Conclusions These findings suggest that heightened reactivity to unpredictable threat may be an important process in PD and AD comorbidity and a possible key motivational factor underlying engagement in alcohol use. PMID:23465734

  8. Alcohol selectively reduces anxiety but not fear: startle response during unpredictable versus predictable threat.

    PubMed

    Moberg, Christine A; Curtin, John J

    2009-05-01

    Recent theory and empirical research have suggested that fear and anxiety are distinct processes with separable neurobiological substrates. Furthermore, a laboratory procedure has been developed to manipulate fear versus anxiety independently via administration of predictable or unpredictable electric shock, respectively. Benzodiazepines appear to selectively reduce anxiety but not fear in this procedure. The primary aim of this experiment was to determine if alcohol produced a similar selective reduction in anxiety. Intoxicated (target blood alcohol concentration of .08%) and nonintoxicated participants viewed a series of colored squares separated by variable intertrial intervals (ITIs) in 3 conditions. In the predictable shock condition, shocks were administered contingently during every square. In the unpredictable shock condition, shocks were administered noncontingently during both squares and ITIs. In the no-shock condition, no shocks were administered at any time. Alcohol significantly reduced startle potentiation during cues signaling unpredictable but not predictable shock, consistent with the thesis that alcohol selectively reduces anxiety but not fear. In addition, alcohol's effect on startle potentiation during unpredictable shock was mediated by vigilance. This anxiolytic effect may clarify the nature of alcohol's reinforcing effects in social and problem drinkers.

  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. 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.

  11. 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.

  12. Intensity perception. VIII. Loudness comparisons between different types of stimuli.

    PubMed

    Lim, J S; Rabinowtiz, W M; Braida, L D; Durlach, N I

    1977-11-01

    In this paper, we describe an extension of our preliminary theory of intensity resolution [Durlach and Braida, J. Acoust. Soc. Am. 46, 372-383 (1969)] to include loudness comparisons among different types of stimuli. The extended theory relates mean loudness matches to discrimination and provides a framework for the interpretation of results on the intrasubject variability of loudness comparisons. The predicted relation between mean loudness matches and discrimination is essentially the same as that proposed by Riesz [J. Acoust. Soc. Am. 5, 211-216 (1933)]. With regard to the variability of loudness comparisons, the extended model is essentially the same as the preliminary model except that a new term is included in the trace-mode memory variance to account for the dissimilarity of the stimuli being compared. The model is compared to some published data on loudness matching and discrimination and to some new data of our own on the variability of loudness comparisons obtained in a two-interval, roving-level, loudness-discrimination experiment. PMID:915119

  13. Acoustic startle/escape reactions in tethered flying locusts: motor patterns and wing kinematics underlying intentional steering.

    PubMed

    Dawson, J W; Leung, F-H; Robertson, R M

    2004-07-01

    We simultaneously recorded flight muscle activity and wing kinematics in tethered, flying locusts to determine the relationship between asymmetric depressor muscle activation and the kinematics of the stroke reversal at the onset of wing depression during attempted intentional steering manoeuvres. High-frequency, pulsed sounds produced bilateral asymmetries in forewing direct depressor muscles (M97, 98, 99) that were positively correlated with asymmetric forewing depression and asymmetries in stroke reversal timing. Bilateral asymmetries in hindwing depressor muscles (M127 and M128 but not M129) were positively correlated with asymmetric hindwing depression and asymmetries in the timing of the hindwing stroke reversal; M129 was negatively correlated with these shifts. Hindwing depressor asymmetries and wing kinematic changes were smaller and shifted in opposite direction than corresponding measurements of the forewings. These findings suggest that intentional steering manoeuvres employ bulk shifts in depressor muscle timing that affect the timing of the stroke reversals thereby establishing asymmetric wing depression. Finally, we found indications that locusts may actively control the timing of forewing rotation and speculate this may be a mechanism for generating steering torques. These effects would act in concert with forces generated by asymmetric wing depression and angle of attack to establish rapid changes in direction. PMID:15127218

  14. 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

  15. 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. PMID:27365040

  16. Emotional Stimuli and Motor Conversion Disorder

    ERIC Educational Resources Information Center

    Voon, Valerie; Brezing, Christina; Gallea, Cecile; Ameli, Rezvan; Roelofs, Karin; LaFrance, W. Curt, Jr.; Hallett, Mark

    2010-01-01

    Conversion disorder is characterized by neurological signs and symptoms related to an underlying psychological issue. Amygdala activity to affective stimuli is well characterized in healthy volunteers with greater amygdala activity to both negative and positive stimuli relative to neutral stimuli, and greater activity to negative relative to…

  17. Lateralization produced by interaural intensitive disparities appears to be larger for high- vs low-frequency stimuli

    PubMed Central

    Bernstein, Leslie R.; Trahiotis, Constantine

    2011-01-01

    The purpose of this communication is to report the results of a study indicating that a given magnitude of interaural intensitive disparity (IID) produced a larger extent of laterality, as measured via an acoustic pointer, for stimuli centered at 4 kHz than for stimuli centered at 500 Hz. The data and their analysis, taken together, suggest that the findings reflect true across-frequency differences rather than being manifestations of response-related factors. PMID:21302976

  18. 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…

  19. Becoming the center of attention in social anxiety disorder: Startle reactivity to a virtual audience during speech anticipation

    PubMed Central

    Cornwell, Brian R.; Heller, Randi; Biggs, Arter; Pine, Daniel S.; Grillon, Christian

    2012-01-01

    Objective A detailed understanding of how individuals diagnosed with social anxiety disorder (SAD) respond physiologically under social-evaluative threat is lacking. We aimed to isolate the specific components of public speaking that trigger fear in vulnerable individuals and best discriminate among SAD and healthy individuals. Method Sixteen individuals diagnosed with SAD and 16 healthy individuals were asked to prepare and deliver a short speech in a virtual reality (VR) environment. The VR environment simulated standing center stage before a live audience and allowed us to gradually introduce social cues during speech anticipation. Startle eye-blink responses were elicited periodically by white noise bursts presented during anticipation, speech delivery, and recovery in VR, as well as outside VR during an initial habituation phase. Results SAD individuals reported greater distress and state anxiety than healthy individuals across the entire procedure (ps < .005). Analyses of startle reactivity revealed a robust group difference during speech anticipation in VR, specifically as audience members directed their eye gaze and turned their attention toward participants (p < .05, Bonferroni corrected). Conclusions The VR environment is sufficiently realistic to provoke fear and anxiety in individuals highly vulnerable to socially threatening situations. SAD individuals showed potentiated startle, indicative of a strong phasic fear response, specifically when they perceived themselves as occupying the focus of others' attention as speech time approached. Potentiated startle under social-evaluative threat indexes SAD-related fear of negative evaluation. PMID:21034683

  20. Variation in acoustic overstimulation changes tinnitus characteristics.

    PubMed

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

    2015-12-01

    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.

  1. Depersonalization Disorder: Disconnection of Cognitive Evaluation from Autonomic Responses to Emotional Stimuli

    PubMed Central

    Michal, Matthias; Koechel, Ansgar; Canterino, Marco; Adler, Julia; Reiner, Iris; Vossel, Gerhard; Beutel, Manfred E.; Gamer, Matthias

    2013-01-01

    Background Patients with depersonalization disorder (DPD) typically complain about emotional detachment. Previous studies found reduced autonomic responsiveness to emotional stimuli for DPD patients as compared to patients with anxiety disorders. We aimed to investigate autonomic responsiveness to emotional auditory stimuli of DPD patients as compared to patient controls. Furthermore, we examined the modulatory effect of mindful breathing on these responses as well as on depersonalization intensity. Methods 22 DPD patients and 15 patient controls balanced for severity of depression and anxiety, age, sex and education, were compared regarding 1) electrodermal and heart rate data during a resting period, and 2) autonomic responses and cognitive appraisal of standardized acoustic affective stimuli in two conditions (normal listening and mindful breathing). Results DPD patients rated the emotional sounds as significantly more neutral as compared to patient controls and standardized norm ratings. At the same time, however, they responded more strongly to acoustic emotional stimuli and their electrodermal response pattern was more modulated by valence and arousal as compared to patient controls. Mindful breathing reduced severity of depersonalization in DPD patients and increased the arousal modulation of electrodermal responses in the whole sample. Finally, DPD patients showed an increased electrodermal lability in the rest period as compared to patient controls. Conclusions These findings demonstrated that the cognitive evaluation of emotional sounds in DPD patients is disconnected from their autonomic responses to those emotional stimuli. The increased electrodermal lability in DPD may reflect increased introversion and cognitive control of emotional impulses. The findings have important psychotherapeutic implications. PMID:24058547

  2. Transposed stimuli improve sensitivity to envelope-based interaural timing information for stimuli having center frequencies of up to 10 kHz

    NASA Astrophysics Data System (ADS)

    Bernstein, Leslie R.; Trahiotis, Constantine

    2002-05-01

    Threshold interaural temporal disparities (ITDs) at high frequencies are larger than threshold ITDs obtained at low frequencies. Colburn and Esquissaud [J. Acoust. Soc. Am. Suppl. 1 59, S23 (1976)], hypothesized that this reflects differences in peripheral processing of the stimuli rather than in binaural mechanisms that mediate performance. Previously [L. R. Bernstein and C. Trahiotis, J. Acoust. Soc. Am. 109, 2485 (2001)] this hypothesis was supported in ITD-discrimination experiments employing high-frequency ``transposed stimuli'' centered at 4 kHz that were designed to provide high-frequency channels with envelope-based information mimicking that normally available only in low-frequency channels. Here, we report new results using stimuli centered at 4, 6, and 10 kHz. It was found that (1) transposed stimuli can yield relatively small threshold ITDs, even at 6 and 10 kHz, (2) the data could be well accounted for in terms of a constant-criterion change in normalized interaural correlation computed subsequent to bandpass filtering, compression, rectification, and low-pass filtering. In addition, it was found necessary to incorporate a specific limitation to capture the inability of the auditory system to follow envelope fluctuations greater than 150 Hz. [Work supported by NIH DC 04147.

  3. 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.

  4. Deficient aversive-potentiated startle and the triarchic model of psychopathy: The role of boldness.

    PubMed

    Esteller, Àngels; Poy, Rosario; Moltó, Javier

    2016-05-01

    This study examined the contribution of the phenotypic domains of boldness, meanness, and disinhibition of the triarchic conceptualization of psychopathy (Patrick, Fowles, & Krueger, 2009) to deficient aversive-potentiated startle in a mixed-gender sample of 180 undergraduates. Eyeblink responses to noise probes were recorded during a passive picture-viewing task (erotica, neutral, threat, and mutilation). Deficient threat vs. neutral potentiation was uniquely related to increased boldness scores, thus suggesting that the diminished defensive reaction to aversive stimulation is specifically linked to the charm, social potency and venturesomeness features of psychopathy (boldness), but not to features such as callousness, coldheartedness and cruelty traits (meanness), even though both phenotypes theoretically share the same underlying low-fear disposition. Our findings provide further evidence of the differential association between distinct psychopathy components and deficits in defensive reactivity and strongly support the validity of the triarchic model of psychopathy in disentangling the etiology of this personality disorder.

  5. Deficient aversive-potentiated startle and the triarchic model of psychopathy: The role of boldness.

    PubMed

    Esteller, Àngels; Poy, Rosario; Moltó, Javier

    2016-05-01

    This study examined the contribution of the phenotypic domains of boldness, meanness, and disinhibition of the triarchic conceptualization of psychopathy (Patrick, Fowles, & Krueger, 2009) to deficient aversive-potentiated startle in a mixed-gender sample of 180 undergraduates. Eyeblink responses to noise probes were recorded during a passive picture-viewing task (erotica, neutral, threat, and mutilation). Deficient threat vs. neutral potentiation was uniquely related to increased boldness scores, thus suggesting that the diminished defensive reaction to aversive stimulation is specifically linked to the charm, social potency and venturesomeness features of psychopathy (boldness), but not to features such as callousness, coldheartedness and cruelty traits (meanness), even though both phenotypes theoretically share the same underlying low-fear disposition. Our findings provide further evidence of the differential association between distinct psychopathy components and deficits in defensive reactivity and strongly support the validity of the triarchic model of psychopathy in disentangling the etiology of this personality disorder. PMID:27033014

  6. Reactions to sonic booms: a report of two studies and a general evaluation of startle effects.

    PubMed

    Thackray, R I; Touchstone, R M; Bailey, J P

    1975-04-01

    Two separate studies are reported. The first attempted to determine a sonic boom level below which startle would not occurr. Subjects were exposed indoors to six simulated sonic booms having outside overpressures of 50, 30, and 16 N/m-2 (inside levels of 74, 71, and 65 dBA). Approximately 20% of the subjects gave small arm-hand responses to the two higher exposure levels, while none responded to the lowest level. In the second study, subjects were exposed indoors to a series of 12 simulated booms in order to assess habituation effects. Outside overpressures were 130 and 50 N/m-2 (indoor levels of 81 and 72 dBA). Significant, but not complete, habituation occurred to booms of both levels. Autonomic and eyeblink responses, as well as ratings of annoyance, were obtained in both studies. The final section summarizes the expected behavioral, autonomic, and subjective effects of exposure to various levels of sonic booms. PMID:1147871

  7. 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

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

    PubMed

    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

  9. 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.

  10. 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.

  11. 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.

  12. The Effect of Intertalker Variations on Acoustic-Perceptual Mapping in Cantonese and Mandarin Tone Systems

    ERIC Educational Resources Information Center

    Peng, Gang; Zhang, Caicai; Zheng, Hong-Ying; Minett, James W.; Wang, William S.-Y.

    2012-01-01

    Purpose: This study investigates the impact of intertalker variations on the process of mapping acoustic variations on tone categories in two different tone languages. Method: Pitch stimuli manipulated from four voice ranges were presented in isolation through a blocked-talker design. Listeners were instructed to identify the stimuli that they…

  13. Visual stimuli: past and present

    NASA Astrophysics Data System (ADS)

    Westheimer, Gerald

    2013-03-01

    The fundamental properties of light and the principles of the structure and function of the visual system were discovered at a time when the only light sources were the sun and the flame of a candle. Contributions by Newton, Huygens, Thomas Young and Purkinje, Helmholtz's ophthalmoscope - all preceded the first incandescent filament. Light bulbs, Xenon arcs, lasers, light-emitting diodes (LEDs), computer monitors then sequentially enlarged the arsenal, and so did the steps from Nicol prism to Polaroid in polarizing light, and from glass and interference filters to laser light in generating monochromatic light. Technological advances have a deep impact on the research topics at any one time, expanding their scope. In particular, utilization of computers now allows the generation and manipulation of targets permitting questions to be approached that could not have been envisaged at the dawn of the technological era of vision research. Just beyond the immediate grasp of even the most thoughtful vision scientist, however, is the concern that stimulus sets originating in mathematicians' and physicists' toolboxes fail to capture some essential ingredients indigenous to human vision. The quest to study vision with stimuli in its own terms continues.

  14. Cardiorespiratory interactions to external stimuli.

    PubMed

    Bernardi, L; Porta, C; Spicuzza, L; Sleight, P

    2005-09-01

    Respiration is a powerful modulator of heart rate variability, and of baro- or chemo-reflex sensitivity. This occurs via a mechanical effect of breathing that synchronizes all cardiovascular variables at the respiratory rhythm, particularly when this occurs at a particular slow rate coincident with the Mayer waves in arterial pressure (approximately 6 cycles/min). Recitation of the rosary prayer (or of most mantras), induces a marked enhancement of these slow rhythms, whereas random verbalization or random breathing does not. This phenomenon in turn increases baroreflex sensitivity and reduces chemoreflex sensitivity, leading to increases in parasympathetic and reductions in sympathetic activity. The opposite can be seen during either verbalization or mental stress tests. Qualitatively similar effects can be obtained even by passive listening to more or less rhythmic auditory stimuli, such as music, and the speed of the rhythm (rather than the style) appears to be one of the main determinants of the cardiovascular and respiratory responses. These findings have clinical relevance. Appropriate modulation of breathing, can improve/restore autonomic control of cardiovascular and respiratory systems in relevant diseases such as hypertension and heart failure, and might therefore help improving exercise tolerance, quality of life, and ultimately, survival.

  15. 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.

  16. 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.

  17. The pivotal role of the supplementary motor area in startle epilepsy as demonstrated by SEEG epileptogenicity maps.

    PubMed

    Job, Anne-Sophie; De Palma, Luca; Principe, Alessandro; Hoffmann, Dominique; Minotti, Lorella; Chabardès, Stephan; David, Olivier; Kahane, Philippe

    2014-08-01

    Startle seizures belong to reflex epilepsy syndromes. They usually occur in patients with mental deficiency and showing widely extended cortical lesions, often involving the sensorimotor area. Here we report three cases who did not fulfill these criteria, and in whom stereotactic electroencephalography (SEEG) recordings demonstrated the prominent involvement of the supplementary motor area (SMA). Visual analysis was complemented by time-frequency analysis of SEEG signals using a neuroimaging approach (Epileptogenicity Maps), which showed at seizure onset a significant increase of high frequency oscillations (HFOs, 60-100 Hz) over the premotor and prefrontal areas. Critically, in all cases, the SMA showed ictal HFOs at seizure onset and was included in the surgical resection. All patients became seizure-free after surgery, and histopathological examinations showed no specific lesion. These cases suggest the prominent but not exclusive role of SMA in startle seizures, and highlight the fact that surgery can be considered even in the absence of any magnetic resonance imaging (MRI) lesion.

  18. ADORA2A Gene Variation, Caffeine, and Emotional Processing: A Multi-level Interaction on Startle Reflex

    PubMed Central

    Domschke, Katharina; Gajewska, Agnieszka; Winter, Bernward; Herrmann, Martin J; Warrings, Bodo; Mühlberger, Andreas; Wosnitza, Katherina; Glotzbach, Evelyn; Conzelmann, Annette; Dlugos, Andrea; Fobker, Manfred; Jacob, Christian; Arolt, Volker; Reif, Andreas; Pauli, Paul; Zwanzger, Peter; Deckert, Jürgen

    2012-01-01

    There is converging evidence for genetic, biochemical, and neuropsychological factors to increase the risk for anxiety and anxiety disorders. The pathogenesis of anxiety disorders is assumed to be influenced by a complex interaction of these individual risk factors on several levels, affecting intermediate phenotypes of anxiety such as the startle reflex. Thus, in the present double-blind, placebo-controlled study we attempted to paradigmatically investigate a multi-level pathogenetic model of anxiety by testing the effect of 300 mg caffeine citrate as an antagonist at the adenosine A2A receptor vs placebo on the emotion-potentiated (unpleasant, neutral, and pleasant International Affective Picture System pictures) startle reflex in 110 healthy individuals (male=56, female=54) stratified for the adenosine A2A receptor (ADORA2A) 1976T>C polymorphism (rs5751876). In addition to the expected main effect of picture category (highest startle amplitude for unpleasant, lowest for pleasant pictures) groups across all ADORA2A 1976T>C genotype and intervention (caffeine vs placebo) groups, an interaction effect of genotype, intervention, and picture category was discerned: In ADORA2A 1976TT risk genotype carriers, highest startle magnitudes were observed after caffeine administration in response to unpleasant pictures, with this effect arising particularly from the female subgroup. Our data point to a complex, multi-level, and potentially gender-specific pathogenetic model of anxiety, with genetic and biochemical factors interactively increasing the risk of maladaptive emotional processing and thereby possibly also anxiety disorders. The present findings may eventually aid in improving primary and secondary prevention by sharpening the risk profiles of anxiety-prone individuals. PMID:22012471

  19. 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

  20. Controllable optical transparency using an acoustic standing-wave device

    NASA Astrophysics Data System (ADS)

    Moradi, Kamran; El-Zahab, Bilal

    2015-09-01

    In this paper, a suspended-particle device with controllable light transmittance was developed based on acoustic stimuli. Using a glass compartment and carbon particle suspension in an organic solvent, the device responded to acoustic stimulation by alignment of particles. The alignment of light-absorbing carbon particles afforded an increase in light transmittance as high as 84.5% and was controllable based on the control of the frequency and amplitude of the acoustic waves. The device also demonstrated alignment memory rendering it energy-efficient.

  1. Binocular coordination in response to stereoscopic stimuli

    NASA Astrophysics Data System (ADS)

    Liversedge, Simon P.; Holliman, Nicolas S.; Blythe, Hazel I.

    2009-02-01

    Humans actively explore their visual environment by moving their eyes. Precise coordination of the eyes during visual scanning underlies the experience of a unified perceptual representation and is important for the perception of depth. We report data from three psychological experiments investigating human binocular coordination during visual processing of stereoscopic stimuli.In the first experiment participants were required to read sentences that contained a stereoscopically presented target word. Half of the word was presented exclusively to one eye and half exclusively to the other eye. Eye movements were recorded and showed that saccadic targeting was uninfluenced by the stereoscopic presentation, strongly suggesting that complementary retinal stimuli are perceived as a single, unified input prior to saccade initiation. In a second eye movement experiment we presented words stereoscopically to measure Panum's Fusional Area for linguistic stimuli. In the final experiment we compared binocular coordination during saccades between simple dot stimuli under 2D, stereoscopic 3D and real 3D viewing conditions. Results showed that depth appropriate vergence movements were made during saccades and fixations to real 3D stimuli, but only during fixations on stereoscopic 3D stimuli. 2D stimuli did not induce depth vergence movements. Together, these experiments indicate that stereoscopic visual stimuli are fused when they fall within Panum's Fusional Area, and that saccade metrics are computed on the basis of a unified percept. Also, there is sensitivity to non-foveal retinal disparity in real 3D stimuli, but not in stereoscopic 3D stimuli, and the system responsible for binocular coordination responds to this during saccades as well as fixations.

  2. 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.

  3. 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.

  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. Effective Stimuli for Constructing Reliable Neuron Models

    PubMed Central

    Druckmann, Shaul; Berger, Thomas K.; Schürmann, Felix; Hill, Sean; Markram, Henry; Segev, Idan

    2011-01-01

    The rich dynamical nature of neurons poses major conceptual and technical challenges for unraveling their nonlinear membrane properties. Traditionally, various current waveforms have been injected at the soma to probe neuron dynamics, but the rationale for selecting specific stimuli has never been rigorously justified. The present experimental and theoretical study proposes a novel framework, inspired by learning theory, for objectively selecting the stimuli that best unravel the neuron's dynamics. The efficacy of stimuli is assessed in terms of their ability to constrain the parameter space of biophysically detailed conductance-based models that faithfully replicate the neuron's dynamics as attested by their ability to generalize well to the neuron's response to novel experimental stimuli. We used this framework to evaluate a variety of stimuli in different types of cortical neurons, ages and animals. Despite their simplicity, a set of stimuli consisting of step and ramp current pulses outperforms synaptic-like noisy stimuli in revealing the dynamics of these neurons. The general framework that we propose paves a new way for defining, evaluating and standardizing effective electrical probing of neurons and will thus lay the foundation for a much deeper understanding of the electrical nature of these highly sophisticated and non-linear devices and of the neuronal networks that they compose. PMID:21876663

  6. Acoustic emission descriptors

    NASA Astrophysics Data System (ADS)

    Witos, Franciszek; Malecki, Ignacy

    The authors present selected problems associated with acoustic emission interpreted as a physical phenomenon and as a measurement technique. The authors examine point sources of acoustic emission in isotropic, homogeneous linearly elastic media of different shapes. In the case of an unbounded medium the authors give the analytical form of the stress field and the wave shift field of the acoustic emission. In the case of a medium which is unbounded plate the authors give a form for the equations which is suitable for numerical calculation of the changes over time of selected acoustic emission values. For acoustic emission as a measurement technique, the authors represent the output signal as the resultant of a mechanical input value which describes the source, the transient function of the medium, and the transient function of specific components of the measurement loop. As an effect of this notation, the authors introduce the distinction between an acoustic measurement signal and an acoustic measurement impulse. The authors define the basic parameters of an arbitrary impulse. The authors extensively discuss the signal functions of acoustic emission impulses and acoustic emission signals defined in this article as acoustic emission descriptors (or signal functions of acoustic emission impulses) and advanced acoustic emission descriptors (which are either descriptors associated with acoustic emission applications or the signal functions of acoustic emission signals). The article also contains the results of experimental research on three different problems in which acoustic emission descriptors associated with acoustic emission pulses, acoustic emission applications, and acoustic emission signals are used. These problems are respectively: a problem of the amplitude-load characteristics of acoustic emission pulses in carbon samples subjected to compound uniaxial compression, the use of acoustic emission to predict the durability characteristics of conveyor belts, and

  7. 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.

  8. 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.

  9. 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.

  10. Stimuli, Reinforcers, and the Persistence of Behavior

    ERIC Educational Resources Information Center

    Nevin, John A.

    2009-01-01

    This article reviews evidence from basic and translational research with pigeons and humans suggesting that the persistence of operant behavior depends on the contingency between stimuli and reinforcers, and considers some implications for clinical interventions. (Contains 4 figures.)

  11. Emotional stimuli and motor conversion disorder.

    PubMed

    Voon, Valerie; Brezing, Christina; Gallea, Cecile; Ameli, Rezvan; Roelofs, Karin; LaFrance, W Curt; Hallett, Mark

    2010-05-01

    Conversion disorder is characterized by neurological signs and symptoms related to an underlying psychological issue. Amygdala activity to affective stimuli is well characterized in healthy volunteers with greater amygdala activity to both negative and positive stimuli relative to neutral stimuli, and greater activity to negative relative to positive stimuli. We investigated the relationship between conversion disorder and affect by assessing amygdala activity to affective stimuli. We conducted a functional magnetic resonance imaging study using a block design incidental affective task with fearful, happy and neutral face stimuli and compared valence contrasts between 16 patients with conversion disorder and 16 age- and gender-matched healthy volunteers. The patients with conversion disorder had positive movements such as tremor, dystonia or gait abnormalities. We also assessed functional connectivity between the amygdala and regions associated with motor preparation. A group by affect valence interaction was observed. Post hoc analyses revealed that whereas healthy volunteers had greater right amygdala activity to fearful versus neutral compared with happy versus neutral as expected, there were no valence differences in patients with conversion disorder. There were no group differences observed. The time course analysis also revealed greater right amygdala activity in patients with conversion disorder for happy stimuli (t = 2.96, P = 0.006) (with a trend for fearful stimuli, t = 1.81, P = 0.08) compared with healthy volunteers, with a pattern suggestive of impaired amygdala habituation even when controlling for depressive and anxiety symptoms. Using psychophysiological interaction analysis, patients with conversion disorder had greater functional connectivity between the right amygdala and the right supplementary motor area during both fearful versus neutral, and happy versus neutral 'stimuli' compared with healthy volunteers. These results were confirmed with

  12. The apparent immunity of high-frequency ``transposed'' stimuli to low-frequency binaural interference

    NASA Astrophysics Data System (ADS)

    Bernstein, Leslie R.; Trahiotis, Constantine

    2004-11-01

    Discrimination of interaural temporal disparities (ITDs) was measured with either conventional or transposed ``targets'' centered at 4 kHz. The targets were presented either in the presence or absence of a simultaneously gated diotic noise centered at 500 Hz, the interferer. As expected, the presence of the low-frequency interferer resulted in substantially elevated threshold-ITDs for the conventional high-frequency stimuli. In contrast, these interference effects were absent for ITDs conveyed by the high-frequency transposed targets. The binaural interference effects observed with the conventional high-frequency stimuli were well accounted for, quantitatively, by the model described by Heller and Trahiotis [L. M. Heller and C. Trahiotis, J. Acoust. Soc. Am. 99, 3632-3637 (1996)]. The lack of binaural interference effects observed with the high-frequency transposed stimuli was not predicted by that model. It is suggested that transposed stimuli may be one of a class of stimuli that do not foster an obligatory combination of binaural information between low- and high-frequency regions. Under those conditions that do foster such an obligatory combination, one could still consider models of binaural interference, such as the one described in Heller and Trahiotis, to be valid descriptors of binaural processing. .

  13. Effects of Consonant-Vowel Transitions in Speech Stimuli on Cortical Auditory Evoked Potentials in Adults

    PubMed Central

    Doellinger, Michael; Burger, Martin; Hoppe, Ulrich; Bosco, Enrico; Eysholdt, Ulrich

    2011-01-01

    We examined the neural activation to consonant-vowel transitions by cortical auditory evoked potentials (AEPs). The aim was to show whether cortical response patterns to speech stimuli contain components due to one of the temporal features, the voice-onset time (VOT). In seven normal-hearing adults, the cortical responses to four different monosyllabic words were opposed to the cortical responses to noise stimuli with the same temporal envelope as the speech stimuli. Significant hemispheric asymmetries were found for speech but not in noise evoked potentials. The difference signals between the AEPs to speech and corresponding noise stimuli revealed a significant negative component, which correlated with the VOT. The hemispheric asymmetries can be referred to rapid spectral changes. The correlation with the VOT indicates that the significant component in the difference signal reflects the perception of the acoustic change within the consonant-vowel transition. Thus, at the level of automatic processing, the characteristics of speech evoked potentials appear to be determined primarily by temporal aspects of the eliciting stimuli. PMID:21643536

  14. Extinction of fear-potentiated startle: blockade by infusion of an NMDA antagonist into the amygdala.

    PubMed

    Falls, W A; Miserendino, M J; Davis, M

    1992-03-01

    Data derived from in vitro preparations indicate that NMDA receptors play a critical role in synaptic plasticity in the CNS. More recently, in vivo pharmacological manipulations have suggested that an NMDA-dependent process may be involved in specific forms of behavioral plasticity. All of the work thus far has focused on the possible role of NMDA receptors in the acquisition of responses. However, there are many examples in the behavioral literature of learning-induced changes that involve the reduction or elimination of a previously acquired response. Experimental extinction is a primary example of the elimination of a learned response. Experimental extinction is well described in the behavioral literature, but has not received the same attention in the neurobiological literature. As a result, the neural mechanisms that underlie this important form of learning are not at all understood. In the present experiments, the fear-potentiated startle paradigm was employed to begin to investigate neural mechanisms of extinction. The results show that infusion of the NMDA antagonist D,L-2-amino-5-phosphonovaleric acid (AP5) into the amygdala, a limbic structure known to be important for fear conditioning, dose-dependently blocked extinction of conditioned fear. Control experiments showed that the blockade of extinction was neither the result of the permanent disruption of amygdaloid function nor the result of decreased sensitivity of the animals to the conditioned stimulus. Infusion of AP5 into the interpositus nucleus of the cerebellum, a control site, did not block extinction. Finally, intra-amygdala infusion of a selected dose of the non-NMDA antagonist 6-cyano-7-nitroquinoxaline-2,3-dione did not block extinction of conditioned fear. These results, together with a previous report from our laboratory (Miserendino et al., 1990), demonstrate the importance of the amygdala in the elaboration of conditioned fear and suggest that an NMDA-dependent process might underlie the

  15. Automatic detection of unattended changes in room acoustics.

    PubMed

    Frey, Johannes Daniel; Wendt, Mike; Jacobsen, Thomas

    2015-01-01

    Previous research has shown that the human auditory system continuously monitors its acoustic environment, detecting a variety of irregularities (e.g., deviance from prior stimulation regularity in pitch, loudness, duration, and (perceived) sound source location). Detection of irregularities can be inferred from a component of the event-related brain potential (ERP), referred to as the mismatch negativity (MMN), even in conditions in which participants are instructed to ignore the auditory stimulation. The current study extends previous findings by demonstrating that auditory irregularities brought about by a change in room acoustics elicit a MMN in a passive oddball protocol (acoustic stimuli with differing room acoustics, that were otherwise identical, were employed as standard and deviant stimuli), in which participants watched a fiction movie (silent with subtitles). While the majority of participants reported no awareness for any changes in the auditory stimulation, only one out of 14 participants reported to have become aware of changing room acoustics or sound source location. Together, these findings suggest automatic monitoring of room acoustics.

  16. Acoustic hemostasis

    NASA Astrophysics Data System (ADS)

    Crum, Lawrence; Beach, Kirk; Carter, Stephen; Chandler, Wayne; Curra, Francesco; Kaczkowski, Peter; Keilman, George; Khokhlova, Vera; Martin, Roy; Mourad, Pierre; Vaezy, Shahram

    2000-07-01

    In cases of severe injury, physicians speak of a "golden hour"—a brief grace period in which quickly applied, proper therapy can save the life of the patient. Much of this mortality results from exsanguination, i.e., bleeding to death—often from internal hemorrhage. The inability of a paramedic to treat breaches in the vascular system deep within the body or to stem the loss of blood from internal organs is a major reason for the high level of mortality associated with blunt trauma. We have undertaken an extensive research program to treat the problem of internal bleeding. Our approach is as follows: (a) We use scanning ultrasound to identify internal bleeding and hemorrhage, (b) we use ultrasound imaging to locate specific breaches in the vascular system, both from damaged vessels and gross damage to the capillary bed, and (c) we use High Intensity Focused Ultrasound (HIFU) to treat the damaged region and to induce hemostasis. We present a general review of this research with some emphasis on the role of nonlinear acoustics.

  17. [Segmentation, grouping and accentuation during stimuli perception].

    PubMed

    Sokolov, E N; Nezlina, N I

    2009-01-01

    The paper is concerned with grouping, segmentation and accentuation occurring in the processes of stimuli perception. An universal model of these events is based on vector coding in neuronal networks. Grouping is unification of objects or events into collections according to their similarity. Segmentation is separation of such groups up to small ensembles of units. In neuroscience grouping and segmentation are regarded as referred to neural mechanisms underlying perceptual and semantic processes resulting in a phenomenal attachment or separation. It is assumed that stimuli in neuronal nets are encoded by combinations of excitations of cardinal neurons constituting excitation vectors. Differences among stimuli are formed as absolute values of their excitation vector differences. The more different are stimuli the separate are their perceptual and semantic representations. The more similar are respective stimuli, the less is their separation. It suggests that stimuli having similar excitation vectors would be grouped together. On the contrary stimuli with opposed excitation vectors would be segmented and pushed to different ensembles. The vector encoding is expressed also for location in space. Thus spatial separation of objects is increasing with the increasing of their spatial excitation vector differences. The universal principle of vector encoding of differences can be illustrated by color contrast: differences of contrast colors rise with increase of their excitation vector differences. Objects having similar excitation vectors constitute a group accentuated due to summation of their excitation vectors. Groups of objects characterized by different excitation vectors are mutually accentuated by a contrast mechanism. A plastic accentuation depends on novelty of stimulation being habituated during repeated stimulus presentations.

  18. Short term memory for tactile stimuli.

    PubMed

    Gallace, Alberto; Tan, Hong Z; Haggard, Patrick; Spence, Charles

    2008-01-23

    Research has shown that unreported information stored in rapidly decaying visual representations may be accessed more accurately using partial report than using full report procedures (e.g., [Sperling, G., 1960. The information available in brief visual presentations. Psychological Monographs, 74, 1-29.]). In the 3 experiments reported here, we investigated whether unreported information regarding the actual number of tactile stimuli presented in parallel across the body surface can be accessed using a partial report procedure. In Experiment 1, participants had to report the total number of stimuli in a tactile display composed of up to 6 stimuli presented across their body (numerosity task), or else to detect whether or not a tactile stimulus had previously been presented in a position indicated by a visual probe given at a variable delay after offset of a tactile display (i.e., partial report). The results showed that participants correctly reported up to 3 stimuli in the numerosity judgment task, but their performance was significantly better than chance when up to 5 stimuli were presented in the partial report task. This result shows that short-lasting tactile representations can be accessed using partial report procedures similar to those used previously in visual studies. Experiment 2 showed that the duration of these representations (or the time available to consciously access them) depends on the number of stimuli presented in the display (the greater the number of stimuli that are presented, the faster their representation decays). Finally, the results of a third experiment showed that the differences in performance between the numerosity judgment and partial report tasks could not be explained solely in terms of any difference in task difficulty. PMID:18083147

  19. Neural circuits containing olfactory neurons are involved in the prepulse inhibition of the startle reflex in rats

    PubMed Central

    Niu, Haichen; He, Xiaobin; Zhou, Ting; Shi, Xi; Zhang, Qiang; Zhang, Zhijian; Qiao, Yuehua; Xu, Fuqiang; Hu, Min

    2015-01-01

    Many neuropsychiatric disorders, such as schizophrenia, have been associated with olfactory dysfunction and abnormalities in the prepulse inhibition (PPI) response to a startle reflex. However, whether these two abnormalities could be related is unclear. The present investigations were designed to determine whether theblockage of olfactory sensory input by zinc sulfate infusion in the olfactory naris (0.5 ml, 0.17 M, ZnE) can disturb the PPI response. Furthermore, a bilateral microinjection of lidocaine/MK801 in the olfactory bulb (OB) was administered to examine whether the blockage of olfactory sensory input could impair the PPI response. To identify the neural projection between olfaction and PPI-related areas, trans-synaptic retrograde tracing with the recombinant pseudorabies virus (PRV) was used. Our results demonstrated that blockage of olfactory sensory input could disturb olfactory behavior. In the function studies, we demonstrated that blockage of olfactory sensory input could impair the pre-pulse inhibition of the startle response following decreased c-Fos expression in relevant brain regions during the PPI responses. Furthermore, similar and more robust findings indicated that blockage of olfactory sensory input by microinjection of lidocaine/MK801 in the OB could impair the PPI response. In the circuit-level studies, we demonstrated that trans-synaptic retrograde tracing with PRV exhibited a large portion of labeled neurons in several regions of the olfactory cortices from the pedunculopontine tegmental nucleus (PPTg). Thus, these data suggest that the olfactory system participates in the PPI regulating fields and plays a role in the pre-pulse inhibition of the startle response in rats. PMID:25859195

  20. 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

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

    PubMed

    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. Lateralization of high-frequency transposed stimuli under conditions of binaural interference

    NASA Astrophysics Data System (ADS)

    Bernstein, Leslie R.; Trahiotis, Constantine

    2005-04-01

    The purpose of this study was to determine whether binaural interference would occur if ITD-based extents of laterality were measured using high-frequency transposed stimuli as targets. The results of an earlier study [L. R. Bernstein and C. Trahiotis, J. Acoust. Soc. Am. 116, 3062-3069 (2004)], which focused on threshold-ITDs rather than extents of laterality, suggested that high-frequency transposed stimuli might be immune to binaural interference effects resulting from the addition of a spectrally-remote, low-frequency interferer. In contrast to the earlier findings, the data from this study indicate that high-frequency transposed targets can, indeed, be susceptible to binaural interference. High-frequency transposed targets, even when presented along with an interferer, yielded greater extents of ITD-based laterality than did Gaussian noise targets presented in isolation. That is, the enhanced potency of ITDs conveyed by transposed stimuli persisted even in the presence of a low-frequency interferer. Predictions made using an extension of the model of Heller and Trahiotis [L. M. Heller and C. Trahiotis, J. Acoust. Soc. Am. 99, 3632-3637 (1996)] accounted well for binaural interference obtained with conventional Gaussian noise targets but generally over-predicted the amounts of interference found with the transposed targets.

  3. Measures of extents of laterality for high-frequency ``transposed'' stimuli under conditions of binaural interference

    NASA Astrophysics Data System (ADS)

    Bernstein, Leslie R.; Trahiotis, Constantine

    2005-09-01

    Our purpose in this study was to determine whether across-frequency binaural interference would occur if ITD-based extents of laterality were measured using high-frequency transposed stimuli as targets. The results of an earlier study [L. R. Bernstein and C. Trahiotis, J. Acoust. Soc. Am. 116, 3062-3069 (2004)], which focused on threshold-ITDs, rather than extents of laterality, suggested that high-frequency transposed stimuli might be ``immune'' to binaural interference effects resulting from the addition of a spectrally remote, low-frequency interferer. In contrast to the earlier findings, the data from this study indicate that high-frequency transposed targets are susceptible to binaural interference. Nevertheless, high-frequency transposed targets, even when presented along with an interferer, yielded greater extents of ITD-based laterality than did high-frequency Gaussian noise targets presented in isolation. That is, the ``enhanced potency'' of ITDs conveyed by transposed stimuli persisted, even in the presence of a low-frequency interferer. Predictions made using an extension of the model of Heller and Trahiotis [L. M. Heller and C. Trahiotis, J. Acoust. Soc. Am. 99, 3632-3637 (1996)] accounted well for across-frequency binaural interference obtained with conventional Gaussian noise targets but, in all but one case, overpredicted the amounts of interference found with the transposed targets.

  4. 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.

  5. Cannabidiol, among Other Cannabinoid Drugs, Modulates Prepulse Inhibition of Startle in the SHR Animal Model: Implications for Schizophrenia Pharmacotherapy.

    PubMed

    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

  6. 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.

  7. 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

  8. NESSTI: Norms for Environmental Sound Stimuli

    PubMed Central

    Hocking, Julia; Dzafic, Ilvana; Kazovsky, Maria; Copland, David A.

    2013-01-01

    In this paper we provide normative data along multiple cognitive and affective variable dimensions for a set of 110 sounds, including living and manmade stimuli. Environmental sounds are being increasingly utilized as stimuli in the cognitive, neuropsychological and neuroimaging fields, yet there is no comprehensive set of normative information for these type of stimuli available for use across these experimental domains. Experiment 1 collected data from 162 participants in an on-line questionnaire, which included measures of identification and categorization as well as cognitive and affective variables. A subsequent experiment collected response times to these sounds. Sounds were normalized to the same length (1 second) in order to maximize usage across multiple paradigms and experimental fields. These sounds can be freely downloaded for use, and all response data have also been made available in order that researchers can choose one or many of the cognitive and affective dimensions along which they would like to control their stimuli. Our hope is that the availability of such information will assist researchers in the fields of cognitive and clinical psychology and the neuroimaging community in choosing well-controlled environmental sound stimuli, and allow comparison across multiple studies. PMID:24023866

  9. Recall and recognition hypermnesia for Socratic stimuli.

    PubMed

    Kazén, Miguel; Solís-Macías, Víctor M

    2016-01-01

    In two experiments, we investigate hypermnesia, net memory improvements with repeated testing of the same material after a single study trial. In the first experiment, we found hypermnesia across three trials for the recall of word solutions to Socratic stimuli (dictionary-like definitions of concepts) replicating Erdelyi, Buschke, and Finkelstein and, for the first time using these materials, for their recognition. In the second experiment, we had two "yes/no" recognition groups, a Socratic stimuli group presented with concrete and abstract verbal materials and a word-only control group. Using signal detection measures, we found hypermnesia for concrete Socratic stimuli-and stable performance for abstract stimuli across three recognition tests. The control group showed memory decrements across tests. We interpret these findings with the alternative retrieval pathways (ARP) hypothesis, contrasting it with alternative theories of hypermnesia, such as depth of processing, generation and retrieve-recognise. We conclude that recognition hypermnesia for concrete Socratic stimuli is a reliable phenomenon, which we found in two experiments involving both forced-choice and yes/no recognition procedures.

  10. Stimuli-responsive materials in analytical separation.

    PubMed

    Lorenzo, Rosa A; Carro, Antonia M; Concheiro, Angel; Alvarez-Lorenzo, Carmen

    2015-07-01

    This review focuses on the fundamentals of stimuli-responsive materials and their applications to three common separation techniques, namely extraction, chromatography, and electrophoresis. Although still little investigated, materials that switch their affinity for the analyte on and off as a function of tiny changes in physical and biochemical variables offer relevant advantages for analyte extraction, concentration, and separation. Temperature and/or pH-responsive polymers in the form of chains or networks, which are dispersed in the sample as free entities or after being grafted onto beads (which may incorporate magnetic cores), enable quantitative capture and/or elution of the analyte under mild conditions and without needing organic solvents. Regarding liquid-chromatography separation, responsive stationary phases enable the implementation of "all-in-water" procedures in which retention times are modulated by means of temperature or pH gradients. Other stimuli that can be externally applied, for example light or magnetic fields, can also be used for efficient extraction or separation of the target substance without altering the composition of the sample matrix. Moreover, stimuli-responsiveness enables straightforward recycling of solid and/or stationary phases for a prolonged lifetime. Improved understanding of the phase transitions of stimuli-responsive materials and design of suitable formats for analytical applications should enable wider and more successful application of stimuli-responsive materials in analytical separations. PMID:25910881

  11. 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.

  12. What Is an Acoustic Neuroma

    MedlinePlus

    ... Acoustic Neuroma An acoustic neuroma, also called a vestibular schwannoma, is a rare benign tumor of the ... Acoustic Neuroma? An acoustic neuroma, known as a vestibular schwannoma, is a benign (non-cancerous) growth that ...

  13. Time-instant sampling based encoding of time-varying acoustic spectrum

    NASA Astrophysics Data System (ADS)

    Sharma, Neeraj Kumar

    2015-12-01

    The inner ear has been shown to characterize an acoustic stimuli by transducing fluid motion in the inner ear to mechanical bending of stereocilia on the inner hair cells (IHCs). The excitation motion/energy transferred to an IHC is dependent on the frequency spectrum of the acoustic stimuli, and the spatial location of the IHC along the length of the basilar membrane (BM). Subsequently, the afferent auditory nerve fiber (ANF) bundle samples the encoded waveform in the IHCs by synapsing with them. In this work we focus on sampling of information by afferent ANFs from the IHCs, and show computationally that sampling at specific time instants is sufficient for decoding of time-varying acoustic spectrum embedded in the acoustic stimuli. The approach is based on sampling the signal at its zero-crossings and higher-order derivative zero-crossings. We show results of the approach on time-varying acoustic spectrum estimation from cricket call signal recording. The framework gives a time-domain and non-spatial processing perspective to auditory signal processing. The approach works on the full band signal, and is devoid of modeling any bandpass filtering mimicking the BM action. Instead, we motivate the approach from the perspective of event-triggered sampling by afferent ANFs on the stimuli encoded in the IHCs. Though the approach gives acoustic spectrum estimation but it is shallow on its complete understanding for plausible bio-mechanical replication with current mammalian auditory mechanics insights.

  14. "Glass fairies" and "bone children": adolescents and young adults with anorexia nervosa show positive reactions towards extremely emaciated body pictures measured by the startle reflex paradigm.

    PubMed

    Reichel, Valeska A; Schneider, Nora; Grünewald, Barbara; Kienast, Thorsten; Pfeiffer, Ernst; Lehmkuhl, Ulrike; Korte, Alexander

    2014-02-01

    In this study, we investigated the emotional processing of extremely emaciated body cues in adolescents and young adults with (n  =  36) and without (n =  36) anorexia nervosa (AN), introducing a new picture type, which was taken from websites that promote extreme thinness and is targeted specifically at adolescents interested in extreme thinness. A startle reflex paradigm was used for implicit reactions, while a self-assessment instrument was used for subjective responses. We found a significant group difference with a startle inhibition (appetitive response) among the patients and a startle potentiation (aversive response) among the controls, whereas no such difference for subjective measures was found. The results are in contrast to previous studies, which proposed a general failure to activate the appetitive motivational system in AN, but in keeping with findings from other addictions, where the same response pattern has been found. Implications for prevention and therapy are discussed.

  15. 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

  16. Virtual acoustic displays

    NASA Technical Reports Server (NTRS)

    Wenzel, Elizabeth M.

    1991-01-01

    A 3D auditory display can potentially enhance information transfer by combining directional and iconic information in a quite naturalistic representation of dynamic objects in the interface. Another aspect of auditory spatial clues is that, in conjunction with other modalities, it can act as a potentiator of information in the display. For example, visual and auditory cues together can reinforce the information content of the display and provide a greater sense of presence or realism in a manner not readily achievable by either modality alone. This phenomenon will be particularly useful in telepresence applications, such as advanced teleconferencing environments, shared electronic workspaces, and monitoring telerobotic activities in remote or hazardous situations. Thus, the combination of direct spatial cues with good principles of iconic design could provide an extremely powerful and information-rich display which is also quite easy to use. An alternative approach, recently developed at ARC, generates externalized, 3D sound cues over headphones in realtime using digital signal processing. Here, the synthesis technique involves the digital generation of stimuli using Head-Related Transfer Functions (HRTF's) measured in the two ear-canals of individual subjects. Other similar approaches include an analog system developed by Loomis, et. al., (1990) and digital systems which make use of transforms derived from normative mannikins and simulations of room acoustics. Such an interface also requires the careful psychophysical evaluation of listener's ability to accurately localize the virtual or synthetic sound sources. From an applied standpoint, measurement of each potential listener's HRTF's may not be possible in practice. For experienced listeners, localization performance was only slightly degraded compared to a subject's inherent ability. Alternatively, even inexperienced listeners may be able to adapt to a particular set of HRTF's as long as they provide adequate

  17. Modulation rate discrimination using half-wave rectified and sinusoidally amplitude modulated stimuli in cochlear-implant users.

    PubMed

    Kreft, Heather A; Oxenham, Andrew J; Nelson, David A

    2010-02-01

    Detection and modulation rate discrimination were measured in cochlear-implant users for pulse-trains that were either sinusoidally amplitude modulated or were modulated with half-wave rectified sinusoids, which in acoustic hearing have been used to simulate the response to low-frequency temporal fine structure. In contrast to comparable results from acoustic hearing, modulation rate discrimination was not statistically different for the two stimulus types. The results suggest that, in contrast to binaural perception, pitch perception in cochlear-implant users does not benefit from using stimuli designed to more closely simulate the cochlear response to low-frequency pure tones. PMID:20136187

  18. Verbal Establishing Stimuli: Testing the Motivative Effect of Stimuli in a Derived Relation with Consequences

    ERIC Educational Resources Information Center

    Ju, Winifred C.; Hayes, Steven C.

    2008-01-01

    The present study examined whether the presentation of stimuli in equivalence relations with consequences increases the operant behavior that produces these consequences. In Experiment 1, both normal words and experimentally trained equivalence stimuli did so with young children. In Experiment 2, results were similar with college students. Here, a…

  19. 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 ...

  20. Acoustic Neuroma Educational Video

    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 ...

  1. 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.

  2. 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).

  3. 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

  4. 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

  5. Auditory evoked potentials to speech and nonspeech stimuli are associated with verbal skills in preschoolers.

    PubMed

    Kuuluvainen, Soila; Leminen, Alina; Kujala, Teija

    2016-06-01

    Children's obligatory auditory event-related potentials (ERPs) to speech and nonspeech sounds have been shown to associate with reading performance in children at risk or with dyslexia and their controls. However, very little is known of the cognitive processes these responses reflect. To investigate this question, we recorded ERPs to semisynthetic syllables and their acoustically matched nonspeech counterparts in 63 typically developed preschoolers, and assessed their verbal skills with an extensive set of neurocognitive tests. P1 and N2 amplitudes were larger for nonspeech than speech stimuli, whereas the opposite was true for N4. Furthermore, left-lateralized P1s were associated with better phonological and prereading skills, and larger P1s to nonspeech than speech stimuli with poorer verbal reasoning performance. Moreover, left-lateralized N2s, and equal-sized N4s to both speech and nonspeech stimuli were associated with slower naming. In contrast, children with equal-sized N2 amplitudes at left and right scalp locations, and larger N4s for speech than nonspeech stimuli, performed fastest. We discuss the possibility that children’s ERPs reflect not only neural encoding of sounds, but also sound quality processing, memory-trace construction, and lexical access. The results also corroborate previous findings that speech and nonspeech sounds are processed by at least partially distinct neural substrates. PMID:27131343

  6. Potential bronchoconstrictor stimuli in acid fog.

    PubMed

    Balmes, J R; Fine, J M; Gordon, T; Sheppard, D

    1989-02-01

    Acid fog is complex and contains multiple stimuli that may be capable of inducing bronchoconstriction. These stimuli include sulfuric and niric acids, the principal inorganic acids present; sulfites, formed in the atmosphere as a reaction product of sulfur dioxide and water droplets; fog water itself, a hypoosmolar aerosol; the organic acid hydroxymethanesulfonate, the bisulfite adduct of formaldehyde; and gaseous pollutants, e.g., sulfur dioxide, oxides of nitrogen, ozone. Given this complexity, evaluation of the respiratory health effects of naturally occurring acid fog requires assessment of the bronchoconstrictor potency of each component stimulus and possible interactions among these stimuli. We summarize the results of three studies that involve characterization of the bronchoconstrictor potency of acid fog stimuli and/or their interaction in subjects with asthma. The results of the first study indicate that titratable acidity appears to be a more important stimulus to bronchoconstriction than is pH. The results of the second study demonstrate that sulfite species are capable of inducing bronchoconstriction, especially when inhaled at acid pH. The results of the third study suggest that acidity can potentiate hypoosmolar fog-induced bronchoconstriction.

  7. Potential bronchoconstrictor stimuli in acid fog

    SciTech Connect

    Balmes, J.R.; Fine, J.M.; Gordon, T.; Sheppard, D.

    1989-02-01

    Acid fog is complex and contains multiple stimuli that may be capable of inducing bronchoconstriction. These stimuli include sulfuric and nitric acids, the principal inorganic acids present; sulfites, formed in the atmosphere as a reaction product of sulfur dioxide and water droplets; fog water itself, a hypoosmolar aerosol; the organic acid hydroxymethanesulfonate, the bisulfite adduct of formaldehyde; and gaseous pollutants, e.g., sulfur dioxide, oxides of nitrogen, ozone. Given this complexity, evaluation of the respiratory health effects of naturally occurring acid fog requires assessment of the bronchoconstrictor potency of each component stimulus and possible interactions among these stimuli. We summarize the results of three studies that involve characterization of the bronchoconstrictor potency of acid fog stimuli and/or their interaction in subjects with asthma. The results of the first study indicate that titratable acidity appears to be a more important stimulus to bronchoconstriction than is pH. The results of the second study demonstrate that sulfite species are capable of inducing bronchoconstriction, especially when inhaled at acid pH. The results of the third study suggest that acidity can potentiate hypoosmolar fog-induced bronchoconstriction.

  8. Computer programming for generating visual stimuli.

    PubMed

    Bukhari, Farhan; Kurylo, Daniel D

    2008-02-01

    Critical to vision research is the generation of visual displays with precise control over stimulus metrics. Generating stimuli often requires adapting commercial software or developing specialized software for specific research applications. In order to facilitate this process, we give here an overview that allows nonexpert users to generate and customize stimuli for vision research. We first give a review of relevant hardware and software considerations, to allow the selection of display hardware, operating system, programming language, and graphics packages most appropriate for specific research applications. We then describe the framework of a generic computer program that can be adapted for use with a broad range of experimental applications. Stimuli are generated in the context of trial events, allowing the display of text messages, the monitoring of subject responses and reaction times, and the inclusion of contingency algorithms. This approach allows direct control and management of computer-generated visual stimuli while utilizing the full capabilities of modern hardware and software systems. The flowchart and source code for the stimulus-generating program may be downloaded from www.psychonomic.org/archive.

  9. Categorization of Multidimensional Stimuli by Pigeons

    ERIC Educational Resources Information Center

    Berg, Mark E.; Grace, Randolph C.

    2011-01-01

    Six pigeons responded in a visual category learning task in which the stimuli were dimensionally separable Gabor patches that varied in frequency and orientation. We compared performance in two conditions which varied in terms of whether accurate performance required that responding be controlled jointly by frequency and orientation, or…

  10. Contingent Stimuli Signal Subsequent Reinforcer Ratios

    ERIC Educational Resources Information Center

    Boutros, Nathalie; Davison, Michael; Elliffe, Douglas

    2011-01-01

    Conditioned reinforcer effects may be due to the stimulus' discriminative rather than its strengthening properties. While this was demonstrated in a frequently-changing choice procedure, a single attempt to replicate in a relatively static choice environment failed. We contend that this was because the information provided by the stimuli was…

  11. Long-range Acoustic Interactions in Insect Swarms: An Adaptive Gravity Model

    NASA Astrophysics Data System (ADS)

    Gorbonos, Dan; Ianconescu, Reuven; Puckett, James G.; Ni, Rui; Ouellette, Nicholas T.; Gov, Nir S.

    The collective motion of groups of animals emerges from the net effect of the interactions between individual members of the group. In many cases, such as birds, fish, or ungulates, these interactions are mediated by sensory stimuli that predominantly arise from nearby neighbors. But not all stimuli in animal groups are short range. Here, we consider mating swarms of midges, which interact primarily via long-range acoustic stimuli. We exploit the similarity in form between the decay of acoustic and gravitational sources to build a model for swarm behavior. By accounting for the adaptive nature of the midges' acoustic sensing, we show that our ``adaptive gravity'' model makes mean-field predictions that agree well with experimental observations of laboratory swarms. Our results highlight the role of sensory mechanisms and interaction range in collective animal behavior. The adaptive interactions that we present here open a new class of equations of motion, which may appear in other biological contexts.

  12. Relations among pure-tone sound stimuli, neural activity, and the loudness sensation

    NASA Technical Reports Server (NTRS)

    Howes, W. L.

    1972-01-01

    Both the physiological and psychological responses to pure-tone sound stimuli are used to derive formulas which: (1) relate the loudness, loudness level, and sound-pressure level of pure tones; (2) apply continuously over most of the acoustic regime, including the loudness threshold; and (3) contain no undetermined coefficients. Some of the formulas are fundamental for calculating the loudness of any sound. Power-law formulas relating the pure-tone sound stimulus, neural activity, and loudness are derived from published data.

  13. ACOUSTICAL STANDARDS NEWS.

    PubMed

    Stremmel, Neil; Struck, Christopher J

    2016-07-01

    American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, S3/SC 1, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, animal bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes a catalog of Acoustical American National Standards. To receive a copy of the latest Standards catalog, please contact Neil Stremmel.Comments are welcomed on all material in Acoustical Standards News.This Acoustical Standards News section in JASA, as well as the National Catalog of Acoustical Standards and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org. PMID:27475185

  14. 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

  15. 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

  16. Rapid recovery following short-term acoustic disturbance in two fish species.

    PubMed

    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. Sound source localization by hearing preservation patients with and without symmetric, low-frequency acoustic hearing

    PubMed Central

    Loiselle, Louise H.; Dorman, Michael F.; Yost, William A.; Gifford, Rene H.

    2015-01-01

    The aim of this paper was to study sound source localization by cochlear implant (CI) listeners with low-frequency (LF) acoustic hearing in both the operated ear and in the contralateral ear. Eight CI listeners had symmetrical LF acoustic hearing (symm) and four had asymmetric LF acoustic hearing (asymm). The effects of two variables were assessed: (i) the symmetry of the LF thresholds in the two ears and (ii) the presence/absence of bilateral acoustic amplification. Stimuli consisted of low-pass, high pass, and wide-band noise bursts presented in the frontal horizontal plane. Localization accuracy was 23 degrees of error for the symm listeners and 76 degrees of error for the asymm listeners. The presence of a unilateral CI used in conjunction with bilateral LF acoustic hearing does not impair sound source localization accuracy, but amplification for acoustic hearing can be detrimental to sound source localization accuracy. PMID:25832907

  18. Differential effects of subchronic phencyclidine on anxiety in the light-enhanced startle-, light/dark exploration- and open field tests.

    PubMed

    Enkel, Thomas; Thomas, Mara; Bartsch, Dusan

    2013-04-15

    Subchronic treatment with the N-methyl-d-aspartate receptor antagonist phencyclidine (PCP) is a valuable approach to model the symptomatology of schizophrenia, a multi-facetted psychiatric disorder, in rodents. We addressed the question whether subchronic PCP (scPCP) treatment (5 mg/kg bidaily for 7 days) would affect anxiety in rats, since contradictory findings have been reported so far. Anxiety-like behaviour was assessed using the light-enhanced startle paradigm (LES), a method which measures the effect of the natural aversion to light on the startle reflex and does not depend on motivated behaviour or exploratory drive. For comparison, anxiety-like behaviour was measured in the light-dark exploration test (LDT) and in an open field environment (OFT). The scPCP-treatment did not affect baseline startle reactivity or light-enhanced startle, suggesting normal anxiety levels in treated animals. Further, normal anxiety-like behaviour was also found in the OFT. In the LDT, scPCP treated rats displayed shorter latencies to enter the lit compartment and shuttled more between the dark and lit compartments, behaviours indicative of decreased anxiety and/or increased exploratory activity. Our findings therefore suggest that the effects of scPCP-treatment on anxiety-like behaviour are task-dependent and recommend the additional use of tests independent from exploratory drive or other motivated behaviours, such as the LES paradigm.

  19. 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

    2016-04-01

    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. PMID:26923670

  20. The temporal primacy of self-related stimuli and negative stimuli: an ERP-based comparative study.

    PubMed

    Zhu, Min; Luo, Junlong; Zhao, Na; Hu, Yinying; Yan, Lingyue; Gao, Xiangping

    2016-10-01

    Numerous studies have shown there exist attention biases for self-related and negative stimuli. Few studies, however, have been carried out to compare the effects of such stimuli on the neural mechanisms of early attentional alertness and subsequent cognitive processing. The purpose of the present study was to examine the temporal primacy of both self-related stimuli and negative stimuli in the neurophysiologic level. In a modified oddball task, event-related potentials of the deviant stimuli (i.e., self-face, negative face and neutral face) were recorded. Results revealed that larger P2 amplitudes were elicited by self-related and negative stimuli than by neutral stimuli. Negative stimuli, however, elicited shorter P2 latencies than self-related and neutral stimuli. As for the N2 component, self-related and negative stimuli elicited smaller amplitudes and shorter latencies than neutral stimuli, but otherwise did not differ. Self-related stimuli also elicited larger P3 and late positive component (LPC) amplitudes than negative and neutral stimuli. The pattern of results suggests that the primacy of negative stimuli occurred at an early attention stage of processing, while the primacy of self-related stimuli occurred at the subsequent cognitive evaluation and memory stage.

  1. Perception of power modulation of light in conjunction with acoustic stimulation

    NASA Astrophysics Data System (ADS)

    Hahlweg, Cornelius F.; Weyer, Cornelia; Gercke-Hahn, Harald; Gutzmann, Holger L.; Brahmann, Andre; Rothe, Hendrik

    2013-09-01

    The present paper is derived from an ongoing study on the human perception of combined optical and acoustical periodical stimuli. Originating from problems of occupational medicine concerning artificial illumination and certain machinery with coherent optical and acoustical emissions there are effects which are interesting in the context of Optics and Music. Because of the difficulties in evaluation of physical and psychological effects of such coherent stimuli in a first step we questioned if such coherence is perceivable at all. Concept, experimental set-up and first results are discussed in short.

  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. Photonic water dynamically responsive to external stimuli

    NASA Astrophysics Data System (ADS)

    Sano, Koki; Kim, Youn Soo; Ishida, Yasuhiro; Ebina, Yasuo; Sasaki, Takayoshi; Hikima, Takaaki; Aida, Takuzo

    2016-08-01

    Fluids that contain ordered nanostructures with periodic distances in the visible-wavelength range, anomalously exhibit structural colours that can be rapidly modulated by external stimuli. Indeed, some fish can dynamically change colour by modulating the periodic distance of crystalline guanine sheets cofacially oriented in their fluid cytoplasm. Here we report that a dilute aqueous colloidal dispersion of negatively charged titanate nanosheets exhibits structural colours. In this `photonic water', the nanosheets spontaneously adopt a cofacial geometry with an ultralong periodic distance of up to 675 nm due to a strong electrostatic repulsion. Consequently, the photonic water can even reflect near-infrared light up to 1,750 nm. The structural colour becomes more vivid in a magnetic flux that induces monodomain structural ordering of the colloidal dispersion. The reflective colour of the photonic water can be modulated over the entire visible region in response to appropriate physical or chemical stimuli.

  4. Photonic water dynamically responsive to external stimuli.

    PubMed

    Sano, Koki; Kim, Youn Soo; Ishida, Yasuhiro; Ebina, Yasuo; Sasaki, Takayoshi; Hikima, Takaaki; Aida, Takuzo

    2016-01-01

    Fluids that contain ordered nanostructures with periodic distances in the visible-wavelength range, anomalously exhibit structural colours that can be rapidly modulated by external stimuli. Indeed, some fish can dynamically change colour by modulating the periodic distance of crystalline guanine sheets cofacially oriented in their fluid cytoplasm. Here we report that a dilute aqueous colloidal dispersion of negatively charged titanate nanosheets exhibits structural colours. In this 'photonic water', the nanosheets spontaneously adopt a cofacial geometry with an ultralong periodic distance of up to 675 nm due to a strong electrostatic repulsion. Consequently, the photonic water can even reflect near-infrared light up to 1,750 nm. The structural colour becomes more vivid in a magnetic flux that induces monodomain structural ordering of the colloidal dispersion. The reflective colour of the photonic water can be modulated over the entire visible region in response to appropriate physical or chemical stimuli. PMID:27572806

  5. Blind Braille readers mislocate tactile stimuli.

    PubMed

    Sterr, Annette; Green, Lisa; Elbert, Thomas

    2003-05-01

    In a previous experiment, we observed that blind Braille readers produce errors when asked to identify on which finger of one hand a light tactile stimulus had occurred. With the present study, we aimed to specify the characteristics of this perceptual error in blind and sighted participants. The experiment confirmed that blind Braille readers mislocalised tactile stimuli more often than sighted controls, and that the localisation errors occurred significantly more often at the right reading hand than at the non-reading hand. Most importantly, we discovered that the reading fingers showed the smallest error frequency, but the highest rate of stimulus attribution. The dissociation of perceiving and locating tactile stimuli in the blind suggests altered tactile information processing. Neuroplasticity, changes in tactile attention mechanisms as well as the idea that blind persons may employ different strategies for tactile exploration and object localisation are discussed as possible explanations for the results obtained.

  6. Discrimination of auditory stimuli during isoflurane anesthesia.

    PubMed

    Rojas, Manuel J; Navas, Jinna A; Greene, Stephen A; Rector, David M

    2008-10-01

    Deep isoflurane anesthesia initiates a burst suppression pattern in which high-amplitude bursts are preceded by periods of nearly silent electroencephalogram. The burst suppression ratio (BSR) is the percentage of suppression (silent electroencephalogram) during the burst suppression pattern and is one parameter used to assess anesthesia depth. We investigated cortical burst activity in rats in response to different auditory stimuli presented during the burst suppression state. We noted a rapid appearance of bursts and a significant decrease in the BSR during stimulation. The BSR changes were distinctive for the different stimuli applied, and the BSR decreased significantly more when stimulated with a voice familiar to the rat as compared with an unfamiliar voice. These results show that the cortex can show differential sensory responses during deep isoflurane anesthesia.

  7. Photonic water dynamically responsive to external stimuli

    PubMed Central

    Sano, Koki; Kim, Youn Soo; Ishida, Yasuhiro; Ebina, Yasuo; Sasaki, Takayoshi; Hikima, Takaaki; Aida, Takuzo

    2016-01-01

    Fluids that contain ordered nanostructures with periodic distances in the visible-wavelength range, anomalously exhibit structural colours that can be rapidly modulated by external stimuli. Indeed, some fish can dynamically change colour by modulating the periodic distance of crystalline guanine sheets cofacially oriented in their fluid cytoplasm. Here we report that a dilute aqueous colloidal dispersion of negatively charged titanate nanosheets exhibits structural colours. In this ‘photonic water', the nanosheets spontaneously adopt a cofacial geometry with an ultralong periodic distance of up to 675 nm due to a strong electrostatic repulsion. Consequently, the photonic water can even reflect near-infrared light up to 1,750 nm. The structural colour becomes more vivid in a magnetic flux that induces monodomain structural ordering of the colloidal dispersion. The reflective colour of the photonic water can be modulated over the entire visible region in response to appropriate physical or chemical stimuli. PMID:27572806

  8. 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.

  9. Observing of chain-schedule stimuli.

    PubMed

    Slezak, Jonathan M; Anderson, Karen G

    2014-06-01

    A classical-conditioning account of the processes maintaining behavior under chained schedules entails a backward transmission of conditioned-reinforcement effects. Assessing this process in traditional chain schedules is limited because the response maintained by stimulus onset accompanied by each link in a chain schedule may also be maintained by the primary reinforcer. In the present experiment, an observing response was used to measure the conditioned-reinforcing effects of stimuli associated with a three-link chain variable-time (VT) food schedule, and resistance-to-change tests (extinction and prefeeding) were implemented to examine if a backward transmission of reinforcement effects occur. Four pigeons served as subjects. Observing was maintained by the production of stimuli correlated with links of a three-link chain VT schedule with the middle-link stimulus maintaining the highest rate of observing, followed by the initial-link stimulus and the terminal-link stimulus maintaining the lowest observing rate. Results from resistance-to-change tests of extinction and prefeeding were not supportive of a backward transmission of reinforcement effects and in general, the pattern of resistance-to-change was forward. Based on past and current research, it appears that a backward pattern of relative rate decreases in responses maintained by stimuli correlated with a chain schedule due to disruption (i.e., extinction and prefeeding) is not a ubiquitous process that is evident within different chain-schedule arrangements.

  10. Anagrus breviphragma Soyka Short Distance Search Stimuli

    PubMed Central

    Chiappini, Elisabetta; Berzolla, Alessia; Oppo, Annalisa

    2015-01-01

    Anagrus breviphragma Soyka (Hymenoptera: Mymaridae) successfully parasitises eggs of Cicadella viridis (L.) (Homoptera: Cicadellidae), embedded in vegetal tissues, suggesting the idea of possible chemical and physical cues, revealing the eggs presence. In this research, three treatments were considered in order to establish which types of cue are involved: eggs extracted from leaf, used as a control, eggs extracted from leaf and cleaned in water and ethanol, used to evaluate the presence of chemicals soluble in polar solvents, and eggs extracted from leaf and covered with Parafilm (M), used to avoid physical stimuli due to the bump on the leaf surface. The results show that eggs covered with Parafilm present a higher number of parasitised eggs and a lower probing starting time with respect to eggs washed with polar solvents or eggs extracted and untreated, both when the treatments were singly tested or when offered in sequence, independently of the treatment position. These results suggest that the exploited stimuli are not physical due to the bump but chemicals that can spread in the Parafilm, circulating the signal on the whole surface, and that the stimuli that elicit probing and oviposition are not subjected to learning. PMID:26543865

  11. Visual stimuli recruit intrinsically generated cortical ensembles.

    PubMed

    Miller, Jae-eun Kang; Ayzenshtat, Inbal; Carrillo-Reid, Luis; Yuste, Rafael

    2014-09-23

    The cortical microcircuit is built with recurrent excitatory connections, and it has long been suggested that the purpose of this design is to enable intrinsically driven reverberating activity. To understand the dynamics of neocortical intrinsic activity better, we performed two-photon calcium imaging of populations of neurons from the primary visual cortex of awake mice during visual stimulation and spontaneous activity. In both conditions, cortical activity is dominated by coactive groups of neurons, forming ensembles whose activation cannot be explained by the independent firing properties of their contributing neurons, considered in isolation. Moreover, individual neurons flexibly join multiple ensembles, vastly expanding the encoding potential of the circuit. Intriguingly, the same coactive ensembles can repeat spontaneously and in response to visual stimuli, indicating that stimulus-evoked responses arise from activating these intrinsic building blocks. Although the spatial properties of stimulus-driven and spontaneous ensembles are similar, spontaneous ensembles are active at random intervals, whereas visually evoked ensembles are time-locked to stimuli. We conclude that neuronal ensembles, built by the coactivation of flexible groups of neurons, are emergent functional units of cortical activity and propose that visual stimuli recruit intrinsically generated ensembles to represent visual attributes. PMID:25201983

  12. Stimuli-responsive polymersomes for cancer therapy.

    PubMed

    Thambi, Thavasyappan; Park, Jae Hyung; Lee, Doo Sung

    2016-01-01

    Cancer is the leading cause of mortality and remains a major challenge for modern chemotherapy. Recent advances in cancer therapy have made a modest impact on patient survival. Nanomedicine represents an innovative field with significant potential to improve cancer treatment. Nanomedicine utilizes numerous nanoconstructs, including polymersomes, micelles, and drug conjugates, to deliver therapeutic agents at the target site of interest. In particular, polymeric vesicles, also known as polymersomes, are self-assembled amphiphilic polymers in which an aqueous compartment is enclosed by a thick bilayer membrane. Unlike liposomes, polymersomes consist of high-molecular-weight amphiphilic polymer analogues. Since polymersomes are prepared using synthetic amphiphilic polymers, the bilayer membrane thickness can be readily altered by tuning the molecular weight of hydrophobic blocks. As a consequence, the polymersomes prepared from high-molecular-weight amphiphiles strengthen their membranes, making them inherently more stable than liposomes. The intriguing aggregation of polymersomes offers numerous advantages, including stability, tunable membrane properties, and the capability of encapsulating hydrophilic and hydrophobic agents. Owing to these properties, polymersomes are attractive candidates for various applications such as drug delivery, gene therapy, and tissue engineering. Although these properties have placed polymersomes at the forefront of drug delivery applications, to attain an enhanced therapeutic effect polymersomes are supposed to rapidly release the drug at the target site. To fulfill this requirement, stimuli-responsive polymersomes that respond to various internal or external stimuli have been developed. This review focuses on recently developed stimuli-responsive polymersomes and their potential application in cancer therapy.

  13. Spatial Brightness Perception of Trichromatic Stimuli

    SciTech Connect

    Royer, Michael P.; Houser, Kevin W.

    2012-11-16

    An experiment was conducted to examine the effect of tuning optical radiation on brightness perception for younger (18-25 years of age) and older (50 years of age or older) observers. Participants made forced-choice evaluations of the brightness of a full factorial of stimulus pairs selected from two groups of four metameric stimuli. The large-field stimuli were created by systematically varying either the red or the blue primary of an RGB LED mixture. The results indicate that light stimuli of equal illuminance and chromaticity do not appear equally bright to either younger or older subjects. The rank-order of brightness is not predicted by any current model of human vision or theory of brightness perception including Scotopic to Photopic or Cirtopic to Photopic ratio theory, prime color theory, correlated color temperature, V(λ)-based photometry, color quality metrics, linear brightness models, or color appearance models. Age may affect brightness perception when short-wavelength primaries are used, especially those with a peak wavelength shorter than 450 nm. The results suggest further development of metrics to predict brightness perception is warranted, and that including age as a variable in predictive models may be valuable.

  14. Liquid Helium Acoustic Microscope.

    NASA Astrophysics Data System (ADS)

    Steer, Andrew Paul

    Available from UMI in association with The British Library. In an acoustic microscope, images are generated by monitoring the intensity of the ultrasonic reflection, or echo, from the surface of a sample. In order to achieve this a pulse of acoustic energy is produced by the excitation of a thin film transducer. The pulse thus generated propagates through a crystal and is incident upon the acoustic lens surface, which is the boundary between the crystal and an acoustic coupling liquid. The acoustic lens is a converging element, and brings the ultrasonic beam to a focus within the liquid. A sample, placed at the focus, can act as a reflector, and the returned pulse then contains information regarding the acoustic reflectivity of this specimen. Acoustic pulses are repeatedly launched and detected while the acoustic lens is scanned over the surface of the sample. In this manner an acoustic image is constructed. Acoustic losses in room temperature liquid coupling media represent a considerable source of difficulty in the recovery of acoustic echo signals. At the frequencies of operation required in a microscope which is capable of high resolution, the ultrasonic attenuation is not only large but increases with the square of frequency. In superfluid liquid helium at temperatures below 0.1 K, however, the ultrasonic attenuation becomes negligible. Furthermore, the low sound velocity in liquid helium results in an increase in resolution, since the acoustic wavelength is proportional to velocity. A liquid helium acoustic microscope has been designed and constructed. Details of the various possible detection methods are given, and comparisons are made between them. Measurements of the performance of the system that was adopted are reported. The development of a cooled preamplifier is also described. The variation of reflected signal with object distance has been measured and compared with theoretical predictions. This variation is important in the analysis of acoustic

  15. Nonlinear Acoustics in Fluids

    NASA Astrophysics Data System (ADS)

    Lauterborn, Werner; Kurz, Thomas; Akhatov, Iskander

    At high sound intensities or long propagation distances at in fluids sufficiently low damping acoustic phenomena become nonlinear. This chapter focuses on nonlinear acoustic wave properties in gases and liquids. The origin of nonlinearity, equations of state, simple nonlinear waves, nonlinear acoustic wave equations, shock-wave formation, and interaction of waves are presented and discussed. Tables are given for the nonlinearity parameter B/A for water and a range of organic liquids, liquid metals and gases. Acoustic cavitation with its nonlinear bubble oscillations, pattern formation and sonoluminescence (light from sound) are modern examples of nonlinear acoustics. The language of nonlinear dynamics needed for understanding chaotic dynamics and acoustic chaotic systems is introduced.

  16. Acoustic Levitator Maintains Resonance

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Gaspar, M. S.

    1986-01-01

    Transducer loading characteristics allow resonance tracked at high temperature. Acoustic-levitation chamber length automatically adjusted to maintain resonance at constant acoustic frequency as temperature changes. Developed for containerless processing of materials at high temperatures, system does not rely on microphones as resonance sensors, since microphones are difficult to fabricate for use at temperatures above 500 degrees C. Instead, system uses acoustic transducer itself as sensor.

  17. Interaural differences in the bottlenose dolphin (Tursiops truncatus) auditory nerve response to jawphone click stimuli.

    PubMed

    Mulsow, Jason; Finneran, James J; Houser, Dorian S

    2014-09-01

    Suction cup transducers, also known as "jawphones," are now commonly used to deliver acoustic stimuli to odontocete cetaceans during hearing studies. It is often assumed that stimulation is primarily limited to the ear ipsilateral to a jawphone; however, the actual differences in auditory stimulation at the two ears are not well understood. To examine these differences, auditory evoked potentials (AEPs) were simultaneously recorded from both ears during jawphone stimulation in two bottlenose dolphins. The amplitudes and latencies of auditory nerve responses (ANRs) elicited by broadband clicks were measured as functions of stimulus level and used to estimate the difference in received level and interaural time difference (ITD) between the two ears. Results indicated that clicks received at the ear contralateral to the jawphone were attenuated by approximately 20 dB relative to the level at the ipsilateral ear. The ITD between the contralateral and ipsilateral ears was 70 μs for the first dolphin and 118 μs for the second dolphin. While these results provide support for a notable degree of acoustic isolation of the ears for jawphone-delivered stimuli, there are implications for studies involving processes such as sound localization and unilateral hearing loss.

  18. 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

  19. Localized acoustic surface modes

    NASA Astrophysics Data System (ADS)

    Farhat, Mohamed; Chen, Pai-Yen; Bağcı, Hakan

    2016-04-01

    We introduce the concept of localized acoustic surface modes. We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

  20. 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.

  1. The facilitation of motor actions by acoustic and electric stimulation.

    PubMed

    Marinovic, Welber; Milford, Magdalene; Carroll, Timothy; Riek, Stephan

    2015-12-01

    The presentation of a loud acoustic stimulus during the preparation of motor actions can both speed movement initiation and increase response vigor. Several recent studies have explored this phenomenon as a means to investigate the mechanisms and neural correlates of movement preparation. Here, we sought to determine the generality of this effect across sensory modalities, and in particular whether unexpected somatosensory stimulation can facilitate movements in a manner similar to loud sounds. We show that electric and acoustic stimuli can be similarly effective in inducing the early release of motor actions, in both reaction time and anticipatory timing tasks. Consistent with recent response activation models of motor preparation, we also demonstrate that increasing the intensity of electric stimuli induces both progressive decreases in reaction time and increases in response vigor. Additionally, we show that the early release of motor actions can be induced by electric stimuli targeting predominantly either muscle afferents or skin afferents. Finally, we show that simultaneous acoustic and electric stimulation leads to earlier releases of anticipatory actions than either unimodal stimulus. These findings may lead to new avenues for experimental and clinical exploitation of the effects of accessory sensory information on movement preparation and initiation. PMID:26338375

  2. Acoustic Levitation With Less Equipment

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Jacobi, N.

    1983-01-01

    Certain chamber shapes require fewer than three acoustic drivers. Levitation at center of spherical chamber attained using only one acoustic driver. Exitation of lowest spherical mode produces asymmetric acoustic potential well.

  3. Auditory ERP response to successive stimuli in infancy.

    PubMed

    Chen, Ao; Peter, Varghese; Burnham, Denis

    2016-01-01

    Background. Auditory Event-Related Potentials (ERPs) are useful for understanding early auditory development among infants, as it allows the collection of a relatively large amount of data in a short time. So far, studies that have investigated development in auditory ERPs in infancy have mainly used single sounds as stimuli. Yet in real life, infants must decode successive rather than single acoustic events. In the present study, we tested 4-, 8-, and 12-month-old infants' auditory ERPs to musical melodies comprising three piano notes, and examined ERPs to each individual note in the melody. Methods. Infants were presented with 360 repetitions of a three-note melody while EEG was recorded from 128 channels on the scalp through a Geodesic Sensor Net. For each infant, both latency and amplitude of auditory components P1 and N2 were measured from averaged ERPs for each individual note. Results. Analysis was restricted to response collected at frontal central site. For all three notes, there was an overall reduction in latency for both P1 and N2 over age. For P1, latency reduction was significant from 4 to 8 months, but not from 8 to 12 months. N2 latency, on the other hand, decreased significantly from 4 to 8 to 12 months. With regard to amplitude, no significant change was found for either P1 or N2. Nevertheless, the waveforms of the three age groups were qualitatively different: for the 4-month-olds, the P1-N2 deflection was attenuated for the second and the third notes; for the 8-month-olds, such attenuation was observed only for the middle note; for the 12-month-olds, the P1 and N2 peaks show relatively equivalent amplitude and peak width across all three notes. Conclusion. Our findings indicate that the infant brain is able to register successive acoustic events in a stream, and ERPs become better time-locked to each composite event over age. Younger infants may have difficulties in responding to late occurring events in a stream, and the onset response to the

  4. Auditory ERP response to successive stimuli in infancy

    PubMed Central

    Peter, Varghese; Burnham, Denis

    2016-01-01

    Background. Auditory Event-Related Potentials (ERPs) are useful for understanding early auditory development among infants, as it allows the collection of a relatively large amount of data in a short time. So far, studies that have investigated development in auditory ERPs in infancy have mainly used single sounds as stimuli. Yet in real life, infants must decode successive rather than single acoustic events. In the present study, we tested 4-, 8-, and 12-month-old infants’ auditory ERPs to musical melodies comprising three piano notes, and examined ERPs to each individual note in the melody. Methods. Infants were presented with 360 repetitions of a three-note melody while EEG was recorded from 128 channels on the scalp through a Geodesic Sensor Net. For each infant, both latency and amplitude of auditory components P1 and N2 were measured from averaged ERPs for each individual note. Results. Analysis was restricted to response collected at frontal central site. For all three notes, there was an overall reduction in latency for both P1 and N2 over age. For P1, latency reduction was significant from 4 to 8 months, but not from 8 to 12 months. N2 latency, on the other hand, decreased significantly from 4 to 8 to 12 months. With regard to amplitude, no significant change was found for either P1 or N2. Nevertheless, the waveforms of the three age groups were qualitatively different: for the 4-month-olds, the P1–N2 deflection was attenuated for the second and the third notes; for the 8-month-olds, such attenuation was observed only for the middle note; for the 12-month-olds, the P1 and N2 peaks show relatively equivalent amplitude and peak width across all three notes. Conclusion. Our findings indicate that the infant brain is able to register successive acoustic events in a stream, and ERPs become better time-locked to each composite event over age. Younger infants may have difficulties in responding to late occurring events in a stream, and the onset response to

  5. Acoustic and non-acoustic factors in modeling listener-specific performance of sagittal-plane sound localization

    PubMed Central

    Majdak, Piotr; Baumgartner, Robert; Laback, Bernhard

    2014-01-01

    The ability of sound-source localization in sagittal planes (along the top-down and front-back dimension) varies considerably across listeners. The directional acoustic spectral features, described by head-related transfer functions (HRTFs), also vary considerably across listeners, a consequence of the listener-specific shape of the ears. It is not clear whether the differences in localization ability result from differences in the encoding of directional information provided by the HRTFs, i.e., an acoustic factor, or from differences in auditory processing of those cues (e.g., spectral-shape sensitivity), i.e., non-acoustic factors. We addressed this issue by analyzing the listener-specific localization ability in terms of localization performance. Directional responses to spatially distributed broadband stimuli from 18 listeners were used. A model of sagittal-plane localization was fit individually for each listener by considering the actual localization performance, the listener-specific HRTFs representing the acoustic factor, and an uncertainty parameter representing the non-acoustic factors. The model was configured to simulate the condition of complete calibration of the listener to the tested HRTFs. Listener-specifically calibrated model predictions yielded correlations of, on average, 0.93 with the actual localization performance. Then, the model parameters representing the acoustic and non-acoustic factors were systematically permuted across the listener group. While the permutation of HRTFs affected the localization performance, the permutation of listener-specific uncertainty had a substantially larger impact. Our findings suggest that across-listener variability in sagittal-plane localization ability is only marginally determined by the acoustic factor, i.e., the quality of directional cues found in typical human HRTFs. Rather, the non-acoustic factors, supposed to represent the listeners' efficiency in processing directional cues, appear to be

  6. Children's Preference for Stimuli Associated with Being Imitated.

    ERIC Educational Resources Information Center

    Parton, David A.; Priefert, Maria J.

    Forty-eight preschool children were run under a classical conditioning paradigm in which some neutral stimuli were repeatedly associated with an adult matching the behavior of the subject, and other neutral stimuli were associated with the same adult mismatching the behavior of the subject. Preference for the stimuli associated with being matched…

  7. Developmental Changes in Infant Attention to Dynamic and Static Stimuli

    ERIC Educational Resources Information Center

    Shaddy, D. Jill; Colombo, John

    2004-01-01

    This study examined 4- and 6-month-olds' responses to static or dynamic stimuli using behavioral and heart-rate-defined measures of attention. Infants looked longest to dynamic stimuli with an audio track and least to a static stimulus that was mute. Overall, look duration declined with age to the different stimuli. The amount of time spent in…

  8. Olfactory Stimuli Increase Presence in Virtual Environments

    PubMed Central

    Munyan, Benson G.; Neer, Sandra M.; Beidel, Deborah C.; Jentsch, Florian

    2016-01-01

    Background Exposure therapy (EXP) is the most empirically supported treatment for anxiety and trauma-related disorders. EXP consists of repeated exposure to a feared object or situation in the absence of the feared outcome in order to extinguish associated anxiety. Key to the success of EXP is the need to present the feared object/event/situation in as much detail and utilizing as many sensory modalities as possible, in order to augment the sense of presence during exposure sessions. Various technologies used to augment the exposure therapy process by presenting multi-sensory cues (e.g., sights, smells, sounds). Studies have shown that scents can elicit emotionally charged memories, but no prior research has examined the effect of olfactory stimuli upon the patient’s sense of presence during simulated exposure tasks. Methods 60 adult participants navigated a mildly anxiety-producing virtual environment (VE) similar to those used in the treatment of anxiety disorders. Participants had no autobiographical memory associated with the VE. State anxiety, Presence ratings, and electrodermal (EDA) activity were collected throughout the experiment. Results Utilizing a Bonferroni corrected Linear Mixed Model, our results showed statistically significant relationships between olfactory stimuli and presence as assessed by both the Igroup Presence Questionnaire (IPQ: R2 = 0.85, (F(3,52) = 6.625, p = 0.0007) and a single item visual-analogue scale (R2 = 0.85, (F(3,52) = 5.382, p = 0.0027). State anxiety was unaffected by the presence or absence of olfactory cues. EDA was unaffected by experimental condition. Conclusion Olfactory stimuli increase presence in virtual environments that approximate those typical in exposure therapy, but did not increase EDA. Additionally, once administered, the removal of scents resulted in a disproportionate decrease in presence. Implications for incorporating the use of scents to increase the efficacy of exposure therapy is discussed. PMID

  9. Ultrasonographic Investigation of Human Fetus Responses to Maternal Communicative and Non-communicative Stimuli.

    PubMed

    Ferrari, Gabriella A; Nicolini, Ylenia; Demuru, Elisa; Tosato, Cecilia; Hussain, Merhi; Scesa, Elena; Romei, Luisa; Boerci, Maria; Iappini, Emanuela; Dalla Rosa Prati, Guido; Palagi, Elisabetta; Ferrari, Pier F

    2016-01-01

    During pregnancy fetuses are responsive to the external environment, specifically to maternal stimulation. During this period, brain circuits develop to prepare neonates to respond appropriately. The detailed behavioral analysis of fetus' mouth movements in response to mothers' speech may reveal important aspects of their sensorimotor and affective skills; however, to date, no studies have investigated this response. Given that newborns at birth are capable of responding with matched behaviors to the social signals emitted by the caregiver, we hypothesize that such precocious responses could emerge in the prenatal period by exploiting infants' sensitivity to their mother's voice. By means of a two-dimensional (2D) ultrasonography, we assessed whether fetuses at 25 weeks of gestation, showed a congruent mouthmotor response to maternal acoustic stimulation. Mothers were asked to provide different stimuli, each characterized by a different acoustic output (e.g., chewing, yawning, nursery rhymes, etc.) and we recorded the behavioral responses of 29 fetuses. We found that, when mothers sang the syllable LA in a nursery rhyme, fetuses significantly increased mouth openings. Other stimuli provided by the mother did not produce other significant changes in fetus' behavior. This finding suggests that fetuses are sensitive only to specific maternal vocalizations (LA) and that fetal matched responses are rudimentary signs of early mirroring behaviors that become functional in the postnatal period. In conclusion, fetuses seem to be predisposed to respond selectively to specific maternal stimuli. We propose that such responses may play a role in the development of behavioral and emotional attunement with their mothers long before birth.

  10. Ultrasonographic Investigation of Human Fetus Responses to Maternal Communicative and Non-communicative Stimuli

    PubMed Central

    Ferrari, Gabriella A.; Nicolini, Ylenia; Demuru, Elisa; Tosato, Cecilia; Hussain, Merhi; Scesa, Elena; Romei, Luisa; Boerci, Maria; Iappini, Emanuela; Dalla Rosa Prati, Guido; Palagi, Elisabetta; Ferrari, Pier F.

    2016-01-01

    During pregnancy fetuses are responsive to the external environment, specifically to maternal stimulation. During this period, brain circuits develop to prepare neonates to respond appropriately. The detailed behavioral analysis of fetus’ mouth movements in response to mothers’ speech may reveal important aspects of their sensorimotor and affective skills; however, to date, no studies have investigated this response. Given that newborns at birth are capable of responding with matched behaviors to the social signals emitted by the caregiver, we hypothesize that such precocious responses could emerge in the prenatal period by exploiting infants’ sensitivity to their mother’s voice. By means of a two-dimensional (2D) ultrasonography, we assessed whether fetuses at 25 weeks of gestation, showed a congruent mouthmotor response to maternal acoustic stimulation. Mothers were asked to provide different stimuli, each characterized by a different acoustic output (e.g., chewing, yawning, nursery rhymes, etc.) and we recorded the behavioral responses of 29 fetuses. We found that, when mothers sang the syllable LA in a nursery rhyme, fetuses significantly increased mouth openings. Other stimuli provided by the mother did not produce other significant changes in fetus’ behavior. This finding suggests that fetuses are sensitive only to specific maternal vocalizations (LA) and that fetal matched responses are rudimentary signs of early mirroring behaviors that become functional in the postnatal period. In conclusion, fetuses seem to be predisposed to respond selectively to specific maternal stimuli. We propose that such responses may play a role in the development of behavioral and emotional attunement with their mothers long before birth. PMID:27014160

  11. Ultrasonographic Investigation of Human Fetus Responses to Maternal Communicative and Non-communicative Stimuli.

    PubMed

    Ferrari, Gabriella A; Nicolini, Ylenia; Demuru, Elisa; Tosato, Cecilia; Hussain, Merhi; Scesa, Elena; Romei, Luisa; Boerci, Maria; Iappini, Emanuela; Dalla Rosa Prati, Guido; Palagi, Elisabetta; Ferrari, Pier F

    2016-01-01

    During pregnancy fetuses are responsive to the external environment, specifically to maternal stimulation. During this period, brain circuits develop to prepare neonates to respond appropriately. The detailed behavioral analysis of fetus' mouth movements in response to mothers' speech may reveal important aspects of their sensorimotor and affective skills; however, to date, no studies have investigated this response. Given that newborns at birth are capable of responding with matched behaviors to the social signals emitted by the caregiver, we hypothesize that such precocious responses could emerge in the prenatal period by exploiting infants' sensitivity to their mother's voice. By means of a two-dimensional (2D) ultrasonography, we assessed whether fetuses at 25 weeks of gestation, showed a congruent mouthmotor response to maternal acoustic stimulation. Mothers were asked to provide different stimuli, each characterized by a different acoustic output (e.g., chewing, yawning, nursery rhymes, etc.) and we recorded the behavioral responses of 29 fetuses. We found that, when mothers sang the syllable LA in a nursery rhyme, fetuses significantly increased mouth openings. Other stimuli provided by the mother did not produce other significant changes in fetus' behavior. This finding suggests that fetuses are sensitive only to specific maternal vocalizations (LA) and that fetal matched responses are rudimentary signs of early mirroring behaviors that become functional in the postnatal period. In conclusion, fetuses seem to be predisposed to respond selectively to specific maternal stimuli. We propose that such responses may play a role in the development of behavioral and emotional attunement with their mothers long before birth. PMID:27014160

  12. Acoustics Critical Readiness Review

    NASA Technical Reports Server (NTRS)

    Ballard, Kenny

    2010-01-01

    This presentation reviews the status of the acoustic equipment from the medical operations perspective. Included is information about the acoustic dosimeters, sound level meter, and headphones that are planned for use while on orbit. Finally there is information about on-orbit hearing assessments.

  13. Introduction to acoustic emission

    NASA Technical Reports Server (NTRS)

    Possa, G.

    1983-01-01

    Typical acoustic emission signal characteristics are described and techniques which localize the signal source by processing the acoustic delay data from multiple sensors are discussed. The instrumentation, which includes sensors, amplifiers, pulse counters, a minicomputer and output devices is examined. Applications are reviewed.

  14. 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.

  15. Acoustic ground impedance meter

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J. (Inventor)

    1984-01-01

    A method and apparatus are presented for measuring the acoustic impedance of a surface in which the surface is used to enclose one end of the chamber of a Helmholz resonator. Acoustic waves are generated in the neck of the resonator by a piston driven by a variable speed motor through a cam assembly. The acoustic waves are measured in the chamber and the frequency of the generated acoustic waves is measured by an optical device. These measurements are used to compute the compliance and conductance of the chamber and surface combined. The same procedure is followed with a calibration plate having infinite acoustic impedance enclosing the chamber of the resonator to compute the compliance and conductance of the chamber alone. Then by subtracting, the compliance and conductance for the surface is obtained.

  16. Ocean acoustic hurricane classification.

    PubMed

    Wilson, Joshua D; Makris, Nicholas C

    2006-01-01

    Theoretical and empirical evidence are combined to show that underwater acoustic sensing techniques may be valuable for measuring the wind speed and determining the destructive power of a hurricane. This is done by first developing a model for the acoustic intensity and mutual intensity in an ocean waveguide due to a hurricane and then determining the relationship between local wind speed and underwater acoustic intensity. From this it is shown that it should be feasible to accurately measure the local wind speed and classify the destructive power of a hurricane if its eye wall passes directly over a single underwater acoustic sensor. The potential advantages and disadvantages of the proposed acoustic method are weighed against those of currently employed techniques. PMID:16454274

  17. Ocean acoustic hurricane classification.

    PubMed

    Wilson, Joshua D; Makris, Nicholas C

    2006-01-01

    Theoretical and empirical evidence are combined to show that underwater acoustic sensing techniques may be valuable for measuring the wind speed and determining the destructive power of a hurricane. This is done by first developing a model for the acoustic intensity and mutual intensity in an ocean waveguide due to a hurricane and then determining the relationship between local wind speed and underwater acoustic intensity. From this it is shown that it should be feasible to accurately measure the local wind speed and classify the destructive power of a hurricane if its eye wall passes directly over a single underwater acoustic sensor. The potential advantages and disadvantages of the proposed acoustic method are weighed against those of currently employed techniques.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Attentional orienting towards smoking-related stimuli.

    PubMed

    Hogarth, L C; Mogg, K; Bradley, B P; Duka, T; Dickinson, A

    2003-03-01

    According to incentive salience theory, conditioned stimuli (CS+) associated with drug reinforcement acquire the capacity to elicit a conditioned attentional orienting response, which controls drug-seeking and drug-taking behaviour. We sought evidence for this proposal by measuring visual attentional orienting towards smoking pictures presented briefly in the periphery of the visual field, versus control pictures likewise presented, in smokers versus non-smokers. In each trial, smokers and non-smokers responded manually to a dot probe stimulus that appeared in a location previously occupied by either a smoking picture or a control picture. Attentional bias scores were calculated by subtracting the median reaction time (RT) in the former condition from the median RT in the latter condition. In two experiments, light-smokers (smokers of fewer than 20 cigarettes/day) produced a mean bias score that was significantly greater than that of heavy-smokers (smokers of 20 or more cigarettes/day) and non-smokers. In addition, when smokers from the two experiments were pooled, a significant quadratic relationship was found between cigarettes/day and the attentional bias for the smoking stimuli. These findings are consistent with incentive salience theories and dual-process theories of addiction.

  3. Stimuli-Responsive Nanomaterials for Biomedical Applications

    PubMed Central

    2015-01-01

    Nature employs a variety of tactics to precisely time and execute the processes and mechanics of life, relying on sequential sense and response cascades to transduce signaling events over multiple length and time scales. Many of these tactics, such as the activation of a zymogen, involve the direct manipulation of a material by a stimulus. Similarly, effective therapeutics and diagnostics require the selective and efficient homing of material to specific tissues and biomolecular targets with appropriate temporal resolution. These systems must also avoid undesirable or toxic side effects and evade unwanted removal by endogenous clearing mechanisms. Nanoscale delivery vehicles have been developed to package materials with the hope of delivering them to select locations with rates of accumulation and clearance governed by an interplay between the carrier and its cargo. Many modern approaches to drug delivery have taken inspiration from natural activatable materials like zymogens, membrane proteins, and metabolites, whereby stimuli initiate transformations that are required for cargo release, prodrug activation, or selective transport. This Perspective describes key advances in the field of stimuli-responsive nanomaterials while highlighting some of the many challenges faced and opportunities for development. Major hurdles include the increasing need for powerful new tools and strategies for characterizing the dynamics, morphology, and behavior of advanced delivery systems in situ and the perennial problem of identifying truly specific and useful physical or molecular biomarkers that allow a material to autonomously distinguish diseased from normal tissue. PMID:25474531

  4. Mimicking biophysical stimuli within bone tumor microenvironment*

    PubMed Central

    Marturano-Kruik, A.; Yeager, K.; Bach, D.; Villasante, A.; Cimetta, E.; Vunjak-Novakovic, G.

    2016-01-01

    In vivo, cells reside in a complex environment regulating their fate and function. Most of this complexity is lacking in standard in vitro models, leading to readouts falling short of predicting the actual in vivo situation. The use of engineering tools, combined with deep biological knowledge, leads to the development and use of bioreactors providing biologically sound niches. Such bioreactors offer new tools for biological research, and are now also entering the field of cancer research. Here we present the development and validation of a modular bioreactor system providing: (i) high throughput analyses, (ii) a range of biological conditions, (iii) high degree of control, and (iv) application of physiological stimuli to the cultured samples. The bioreactor was used to engineer a three-dimensional (3D) tissue model of cancer, where the effects of mechanical stimulation on the tumor phenotype were evaluated. Mechanical stimuli applied to the engineered tumor model activated the mechanotransduction machinery and resulted in measurable changes of mRNA levels towards a more aggressive tumor phenotype. PMID:26737062

  5. Dynamic stimuli: accentuating aesthetic preference biases.

    PubMed

    Friedrich, Trista E; Harms, Victoria L; Elias, Lorin J

    2014-01-01

    Despite humans' preference for symmetry, artwork often portrays asymmetrical characteristics that influence the viewer's aesthetic preference for the image. When presented with asymmetrical images, aesthetic preference is often given to images whose content flows from left-to-right and whose mass is located on the right of the image. Cerebral lateralization has been suggested to account for the left-to-right directionality bias; however, the influence of cultural factors, such as scanning habits, on aesthetic preference biases is debated. The current research investigates aesthetic preference for mobile objects and landscapes, as previous research has found contrasting preference for the two image types. Additionally, the current experiment examines the effects of dynamic movement on directionality preference to test the assumption that static images are perceived as aesthetically equivalent to dynamic images. After viewing mirror-imaged pairs of pictures and videos, right-to-left readers failed to show a preference bias, whereas left-to-right readers preferred stimuli with left-to-right directionality regardless of the location of the mass. The directionality bias in both reading groups was accentuated by the videos, but the bias was significantly stronger in left-to-right readers. The findings suggest that scanning habits moderate the leftward bias resulting from hemispheric specialization and that dynamic stimuli further fluent visual processing.

  6. Escape from serial stimuli leading to food

    PubMed Central

    Dinsmoor, James A.; Lee, Diana M.; Brown, Marceline M.

    1986-01-01

    If the functional relations governing the strength of a conditioned reinforcer correspond to those obtained with other Pavlovian procedures (e.g., Kaplan, 1984), the termination of stimuli appearing early in the interval between successive food deliveries should be reinforcing. During initial training we presented four key colors, followed by food, in a recurrent sequence to each of 6 pigeons. This established a baseline level of autoshaped pecking. In later sessions, we terminated each of these colors or only the first color for a brief period following each peck, replacing the original color with a standard substitute to avoid darkening the key. Pecking decreased in the presence of the last color in the sequence but increased in the presence of the first. In accord with contemporary models of Pavlovian conditioning, these and other data suggest that the behavioral effects of stimuli in a chain may be better understood in terms of what each stimulus predicts, as measured by relative time to the terminal reinforcer, than in the exclusively positive terms of the traditional formulation (Skinner, 1938). The same model may also account for the initial pause under fixed-interval and fixed-ratio schedules of reinforcement. PMID:16812462

  7. Reaction time to changes in the tempo of acoustic pulse trains.

    NASA Technical Reports Server (NTRS)

    Smith, R. P.; Warm, J. S.; Westendorf, D. H.

    1973-01-01

    Investigation of the ability of human observers to detect accelerations and decelerations in the rate of presentation of pulsed stimuli, i.e., changes in the tempo of acoustic pulse trains. Response times to accelerations in tempo were faster than to decelerations. Overall speed of response was inversely related to the pulse repetition rate.

  8. Chills in Different Sensory Domains: Frisson Elicited by Acoustical, Visual, Tactile and Gustatory Stimuli

    ERIC Educational Resources Information Center

    Grewe, Oliver; Katzur, Bjorn; Kopiez, Reinhard; Altenmuller, Eckart

    2011-01-01

    "Chills" (frisson manifested as goose bumps or shivers) have been used in an increasing number of studies as indicators of emotions in response to music (e.g., Craig, 2005; Guhn, Hamm, & Zentner, 2007; McCrae, 2007; Panksepp, 1995; Sloboda, 1991). In this study we present evidence that chills can be induced through aural, visual, tactile, and…

  9. 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.

  10. 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.

  11. 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.

  12. Contextual fear conditioning in virtual reality is affected by 5HTTLPR and NPSR1 polymorphisms: effects on fear-potentiated startle

    PubMed Central

    Glotzbach-Schoon, Evelyn; Andreatta, Marta; Reif, Andreas; Ewald, Heike; Tröger, Christian; Baumann, Christian; Deckert, Jürgen; Mühlberger, Andreas; Pauli, Paul

    2013-01-01

    The serotonin (5-HT) and neuropeptide S (NPS) systems are discussed as important genetic modulators of fear and sustained anxiety contributing to the etiology of anxiety disorders. Sustained anxiety is a crucial characteristic of most anxiety disorders which likely develops through contextual fear conditioning. This study investigated if and how genetic alterations of the 5-HT and the NPS systems as well as their interaction modulate contextual fear conditioning; specifically, function polymorphic variants in the genes coding for the 5-HT transporter (5HTT) and the NPS receptor (NPSR1) were studied. A large group of healthy volunteers was therefore stratified for 5HTTLPR (S+ vs. LL carriers) and NPSR1 rs324981 (T+ vs. AA carriers) polymorphisms resulting in four genotype groups (S+/T+, S+/AA, LL/T+, LL/AA) of 20 participants each. All participants underwent contextual fear conditioning and extinction using a virtual reality (VR) paradigm. During acquisition, one virtual office room (anxiety context, CXT+) was paired with an unpredictable electric stimulus (unconditioned stimulus, US), whereas another virtual office room was not paired with any US (safety context, CXT−). During extinction no US was administered. Anxiety responses were quantified by fear-potentiated startle and ratings. Most importantly, we found a gene × gene interaction on fear-potentiated startle. Only carriers of both risk alleles (S+/T+) exhibited higher startle responses in CXT+ compared to CXT−. In contrast, anxiety ratings were only influenced by the NPSR1 polymorphism with AA carriers showing higher anxiety ratings in CXT+ as compared to CXT−. Our results speak in favor of a two level account of fear conditioning with diverging effects on implicit vs. explicit fear responses. Enhanced contextual fear conditioning as reflected in potentiated startle responses may be an endophenotype for anxiety disorders. PMID:23630477

  13. Group Behavioural Responses of Atlantic Salmon (Salmo salar L.) to Light, Infrasound and Sound Stimuli

    PubMed Central

    Bui, Samantha; Oppedal, Frode; Korsøen, Øyvind J.; Sonny, Damien; Dempster, Tim

    2013-01-01

    Understanding species-specific flight behaviours is essential in developing methods of guiding fish spatially, and requires knowledge on how groups of fish respond to aversive stimuli. By harnessing their natural behaviours, the use of physical manipulation or other potentially harmful procedures can be minimised. We examined the reactions of sea-caged groups of 50 salmon (1331±364 g) to short-term exposure to visual or acoustic stimuli. In light experiments, fish were exposed to one of three intensities of blue LED light (high, medium and low) or no light (control). Sound experiments included exposure to infrasound (12 Hz), a surface disturbance event, the combination of infrasound and surface disturbance, or no stimuli. Groups that experienced light, infrasound, and the combination of infrasound and surface disturbance treatments, elicited a marked change in vertical distribution, where fish dived to the bottom of the sea-cage for the duration of the stimulus. Light treatments, but not sound, also reduced the total echo-signal strength (indicative of swim bladder volume) after exposure to light, compared to pre-stimulus levels. Groups in infrasound and combination treatments showed increased swimming activity during stimulus application, with swimming speeds tripled compared to that of controls. In all light and sound treatments, fish returned to their pre-stimulus swimming depths and speeds once exposure had ceased. This work establishes consistent, short-term avoidance responses to these stimuli, and provides a basis for methods to guide fish for aquaculture applications, or create avoidance barriers for conservation purposes. In doing so, we can achieve the manipulation of group position with minimal welfare impacts, to create more sustainable practices. PMID:23691087

  14. Face and Voice as Social Stimuli Enhance Differential Physiological Responding in a Concealed Information Test

    PubMed Central

    Ambach, Wolfgang; Assmann, Birthe; Krieg, Bennet; Vaitl, Dieter

    2012-01-01

    Attentional, intentional, and motivational factors are known to influence the physiological responses in a Concealed Information Test (CIT). Although concealing information is essentially a social action closely related to motivation, CIT studies typically rely on testing participants in an environment lacking of social stimuli: subjects interact with a computer while sitting alone in an experimental room. To address this gap, we examined the influence of social stimuli on the physiological responses in a CIT. Seventy-one participants underwent a mock-crime experiment with a modified CIT. In a between-subjects design, subjects were either questioned acoustically by a pre-recorded male voice presented together with a virtual male experimenter’s uniform face or by a text field on the screen, which displayed the question devoid of face and voice. Electrodermal activity (EDA), respiration line length (RLL), phasic heart rate (pHR), and finger pulse waveform length (FPWL) were registered. The Psychopathic Personality Inventory – Revised (PPI-R) was administered in addition. The differential responses of RLL, pHR, and FPWL to probe vs. irrelevant items were greater in the condition with social stimuli than in the text condition; interestingly, the differential responses of EDA did not differ between conditions. No modulatory influence of the PPI-R sum or subscale scores was found. The results emphasize the relevance of social aspects in the process of concealing information and in its detection. Attentional demands as well as the participants’ motivation to avoid detection might be the important links between social stimuli and physiological responses in the CIT. PMID:23293613

  15. Group behavioural responses of Atlantic salmon (Salmo salar L.) to light, infrasound and sound stimuli.

    PubMed

    Bui, Samantha; Oppedal, Frode; Korsøen, Øyvind J; Sonny, Damien; Dempster, Tim

    2013-01-01

    Understanding species-specific flight behaviours is essential in developing methods of guiding fish spatially, and requires knowledge on how groups of fish respond to aversive stimuli. By harnessing their natural behaviours, the use of physical manipulation or other potentially harmful procedures can be minimised. We examined the reactions of sea-caged groups of 50 salmon (1331 ± 364 g) to short-term exposure to visual or acoustic stimuli. In light experiments, fish were exposed to one of three intensities of blue LED light (high, medium and low) or no light (control). Sound experiments included exposure to infrasound (12 Hz), a surface disturbance event, the combination of infrasound and surface disturbance, or no stimuli. Groups that experienced light, infrasound, and the combination of infrasound and surface disturbance treatments, elicited a marked change in vertical distribution, where fish dived to the bottom of the sea-cage for the duration of the stimulus. Light treatments, but not sound, also reduced the total echo-signal strength (indicative of swim bladder volume) after exposure to light, compared to pre-stimulus levels. Groups in infrasound and combination treatments showed increased swimming activity during stimulus application, with swimming speeds tripled compared to that of controls. In all light and sound treatments, fish returned to their pre-stimulus swimming depths and speeds once exposure had ceased. This work establishes consistent, short-term avoidance responses to these stimuli, and provides a basis for methods to guide fish for aquaculture applications, or create avoidance barriers for conservation purposes. In doing so, we can achieve the manipulation of group position with minimal welfare impacts, to create more sustainable practices. PMID:23691087

  16. Human Superior Temporal Gyrus Organization of Spectrotemporal Modulation Tuning Derived from Speech Stimuli

    PubMed Central

    Hullett, Patrick W.; Hamilton, Liberty S.; Mesgarani, Nima; Schreiner, Christoph E.

    2016-01-01

    The human superior temporal gyrus (STG) is critical for speech perception, yet the organization of spectrotemporal processing of speech within the STG is not well understood. Here, to characterize the spatial organization of spectrotemporal processing of speech across human STG, we use high-density cortical surface field potential recordings while participants listened to natural continuous speech. While synthetic broad-band stimuli did not yield sustained activation of the STG, spectrotemporal receptive fields could be reconstructed from vigorous responses to speech stimuli. We find that the human STG displays a robust anterior–posterior spatial distribution of spectrotemporal tuning in which the posterior STG is tuned for temporally fast varying speech sounds that have relatively constant energy across the frequency axis (low spectral modulation) while the anterior STG is tuned for temporally slow varying speech sounds that have a high degree of spectral variation across the frequency axis (high spectral modulation). This work illustrates organization of spectrotemporal processing in the human STG, and illuminates processing of ethologically relevant speech signals in a region of the brain specialized for speech perception. SIGNIFICANCE STATEMENT Considerable evidence has implicated the human superior temporal gyrus (STG) in speech processing. However, the gross organization of spectrotemporal processing of speech within the STG is not well characterized. Here we use natural speech stimuli and advanced receptive field characterization methods to show that spectrotemporal features within speech are well organized along the posterior-to-anterior axis of the human STG. These findings demonstrate robust functional organization based on spectrotemporal modulation content, and illustrate that much of the encoded information in the STG represents the physical acoustic properties of speech stimuli. PMID:26865624

  17. Stimuli dependent impedance of conductive magnetorheological elastomers

    NASA Astrophysics Data System (ADS)

    Wang, Yu; Xuan, Shouhu; Dong, Bo; Xu, Feng; Gong, Xinglong

    2016-02-01

    The structure dependent impedance of conductive magnetorheological elastomers (MREs) under different loads and magnetic fields has been studied in this work. By increasing the weight fraction of iron particles, the conductivity of the MREs increased. Dynamic mechanical measurements and synchrotron radiation x-ray computed tomography (SR-CT) were used and they provided reasons for the electrical properties changing significantly under pressure and magnetic field stimulation. The high sensitivity of MREs to external stimuli renders them suitable for application in force or magnetic field sensors. The equivalent circuit model was proposed to analyze the impedance response of MREs and it fits the experimental results very well. Each circuit component reflected the change of the inner interface under different conditions, thus relative changes in the microstructure could be distinguished. This method could be used not only to detect the structural changes in the MRE but also to provide a great deal of valuable information for the further understanding of the MR mechanism.

  18. Termination of pinned spirals by local stimuli

    NASA Astrophysics Data System (ADS)

    Chen, Jiang-Xing; Guo, Ming-Ming; Ma, Jun

    2016-02-01

    The termination of pinned spirals on a defect by means of local stimuli is studied. On a completely unexcitable defect, the elimination process is discussed and its corresponding mechanism is presented. Especially, the mechanism of unpinning spirals on a partially unexcitable defect, which has not been investigated so far, is explored. With fixed pacing frequency ω L , there exists a maximal radius R max above which the pinned spiral cannot be removed. It is found that the value of R max does not increase as ω L in a dynamical regime, forming a platform in the R\\textit{max}\\text-ωL curves. Based on analyzing the dispersion relation on the spiral tip around the obstacle, the underlying mechanism is clarified. Also, it is found that when multiple spirals are pinned, the value of R max decreases on a partially unexcitable defect while the change is very slight on a completely unexcitable one.

  19. Working memory of emotional stimuli: Electrophysiological characterization.

    PubMed

    Kessel, Dominique; García-Rubio, María J; González, E Kirstin; Tapia, Manuel; López-Martín, Sara; Román, Francisco J; Capilla, Almudena; Martínez, Kenia; Colom, Roberto; Carretié, Luis

    2016-09-01

    Memorizing emotional stimuli in a preferential way seems to be one of the adaptive strategies brought on by evolution for supporting survival. However, there is a lack of electrophysiological evidence on this bias in working memory. The present study analyzed the influence of emotion on the updating component of working memory. Behavioral and electrophysiological indices were measured from a 3-back task using negative, neutral, and positive faces. Electrophysiological data evidenced an emotional influence on the working memory sensitive P3 component, which presented larger amplitudes for negative matching faces compared to neutral ones. This effect originated in the superior parietal cortex, previously reported to be involved in N-back tasks. Additionally, P3 results showed a correlation with reaction times, where higher amplitudes were associated with faster responses for negative matching faces. These findings indicate that electrophysiological measures seem to be very suitable indices of the emotional influence on working memory.

  20. MULTIFUNCTIONAL AND STIMULI-SENSITIVE PHARMACEUTICAL NANOCARRIERS

    PubMed Central

    Torchilin, Vladimir

    2011-01-01

    Currently used pharmaceutical nanocarriers, such as liposomes, micelles, and polymeric nanoparticles, demonstrate a broad variety of useful properties, such as longevity in the body; specific targeting to certain disease sites; enhanced intracellular penetration; contrast properties allowing for direct carrier visualization in vivo; stimili-sensitivity, and others. Some of those pharmaceutical carriers have already made their way into clinic, while others are still under preclinical development. In certain cases, the pharmaceutical nanocarriers combine several of the listed properties. Long-circulating immunoliposomes capable of prolonged residence in the blood and specific target recognition represent one of examples of this kind. The engineering of multifunctional pharmaceutical nanocarriers combining several useful properties in one particle can significantly enhance the efficacy of many therapeutic and diagnostic protocols. This paper considers the current status and possible future directions in the emerging area of multifunctional nanocarriers with primary attention on the combination of such properties as longevity, targetability, intracellular penetration, contrast loading, and stimuli sensitivity. PMID:18977297

  1. Stimuli-sensitive intrinsically disordered protein brushes

    NASA Astrophysics Data System (ADS)

    Srinivasan, Nithya; Bhagawati, Maniraj; Ananthanarayanan, Badriprasad; Kumar, Sanjay

    2014-10-01

    Grafting polymers onto surfaces at high density to yield polymer brush coatings is a widely employed strategy to reduce biofouling and interfacial friction. These brushes almost universally feature synthetic polymers, which are often heterogeneous and do not readily allow incorporation of chemical functionalities at precise sites along the constituent chains. To complement these synthetic systems, we introduce a biomimetic, recombinant intrinsically disordered protein that can assemble into an environment-sensitive brush. This macromolecule adopts an extended conformation and can be grafted to solid supports to form oriented protein brushes that swell and collapse dramatically with changes in solution pH and ionic strength. We illustrate the value of sequence specificity by using proteases with mutually orthogonal recognition sites to modulate brush height in situ to predictable values. This study demonstrates that stimuli-responsive brushes can be fabricated from proteins and introduces them as a new class of smart biomaterial building blocks.

  2. Calibration of acoustic transients.

    PubMed

    Burkard, Robert

    2006-05-26

    This article reviews the appropriate stimulus parameters (click duration, toneburst envelope) that should be used when eliciting auditory brainstem responses from mice. Equipment specifications required to calibrate these acoustic transients are discussed. Several methods of calibrating the level of acoustic transients are presented, including the measurement of peak equivalent sound pressure level (peSPL) and peak sound pressure level (pSPL). It is hoped that those who collect auditory brainstem response thresholds in mice will begin to use standardized methods of acoustic calibration, so that hearing thresholds across mouse strains obtained in different laboratories can more readily be compared.

  3. 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.

  4. 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.

  5. Acoustic rotation control

    NASA Technical Reports Server (NTRS)

    Elleman, D. D.; Croonquist, A. P.; Wang, T. G. (Inventor)

    1983-01-01

    A system is described for acoustically controlled rotation of a levitated object, which avoids deformation of a levitated liquid object. Acoustic waves of the same wavelength are directed along perpendicular directions across the object, and with the relative phases of the acoustic waves repeatedly switched so that one wave alternately leads and lags the other by 90 deg. The amount of torque for rotating the object, and the direction of rotation, are controlled by controlling the proportion of time one wave leads the other and selecting which wave leads the other most of the time.

  6. 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.

  7. 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.

  8. Underwater acoustic omnidirectional absorber

    NASA Astrophysics Data System (ADS)

    Naify, Christina J.; Martin, Theodore P.; Layman, Christopher N.; Nicholas, Michael; Thangawng, Abel L.; Calvo, David C.; Orris, Gregory J.

    2014-02-01

    Gradient index media, which are designed by varying local element properties in given geometry, have been utilized to manipulate acoustic waves for a variety of devices. This study presents a cylindrical, two-dimensional acoustic "black hole" design that functions as an omnidirectional absorber for underwater applications. The design features a metamaterial shell that focuses acoustic energy into the shell's core. Multiple scattering theory was used to design layers of rubber cylinders with varying filling fractions to produce a linearly graded sound speed profile through the structure. Measured pressure intensity agreed with predicted results over a range of frequencies within the homogenization limit.

  9. Sensitivity to intermodal asynchrony between acoustic and structural vibrations

    NASA Astrophysics Data System (ADS)

    Walker, Kent; Martens, William L.

    2005-04-01

    The purpose of this study was to discover the attributes of musical stimuli which facilitate sensory integration in bi-modal music reproduction systems incorporating sound and whole-body vibration. It was hypothesized that subjective judgments regarding bimodal synchrony would vary depending on the spectral, temporal, and spatial properties of the stimuli. To test this hypothesis, musical instruments with significant low frequency energy and a variety of spectra-temporal envelopes were recorded. These stimuli were then reproduced with varying intermodal delay and overlap in frequency content between displayed vibratory and acoustic components. The air-born component of the bimodal stimuli was presented via a multichannel loudspeaker array, with a direct sound component, as well as a reproduced indirect sound arriving from all around the observer. Psychometric functions were constructed for time order judgment (TOJ) over a range of intermodal delay values. Changes in the slope and intercept of the transformed psychometric functions gave a clear picture of the influence of spectra-temporal and spatial parameters of the multimodal stimuli, the most striking results being the decreased tolerance for intermodal asynchrony associated with instruments recorded in reverberant environments. [Work supported by a Grant from VRQ of the Government of Quebec.

  10. Investigation of correlation of LF power modulation of light in natural and artificial illumination situations and acoustic emission

    NASA Astrophysics Data System (ADS)

    Kleeberg, Florian P.; Gutzmann, Holger L.; Weyer, Cornelia; Weiß, Jürgen; Dörfler, Joachim; Hahlweg, Cornelius F.

    2014-09-01

    The present paper is a follow up of a paper presented in 2013 at the Novel Optical Systems conference in the session on Optics and Music. It is derived from an ongoing study on the human perception of combined optical and acoustical periodical stimuli. Originating from problems concerning artificial illumination and certain machinery with coherent optical and acoustical emissions there are effects to be observed which are interesting in the context of occupational medicine. It seems, that acoustic stimuli in the frequency range of the flicker fusion and below might lead to unexpected perceptible effects beyond those of the single stimuli. The effect of infrasound stimuli as a whole body perception seems to be boosted. Because of the difficulties in evaluation of physical and psychological effects of such coherent stimuli in a first step we question if such coherence is perceivable at all. Further, the problem of modulation of optical signals by acoustical signal is concerned. A catalogue of scenarios and 'effects to look for' including measurement concepts is presented and discussed.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Acoustic Neuroma Association

    MedlinePlus

    ... Platinum Sponsors More from this sponsor... Platinum Sponsor Gold Sponsor University of Colorado Acoustic Neuroma Program Rocky Mountain Gamma Knife Center Gold Sponsor NYU Langone Medical Center Departments of Neurosurgery ...

  16. Acoustic-Levitation Chamber

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Granett, D.; Lee, M. C.

    1984-01-01

    Uncontaminated environments for highly-pure material processing provided within completely sealed levitation chamber that suspends particles by acoustic excitation. Technique ideally suited for material processing in low gravity environment of space.

  17. Multimode Acoustic Research

    NASA Technical Reports Server (NTRS)

    Barmatz, M.

    1985-01-01

    There is a need for high temperature containerless processing facilities that can efficiently position and manipulate molten samples in the reduced gravity environment of space. The goal of the research is to develop sophisticated high temperature manipulation capabilities such as selection of arbitrary axes rotation and rapid sample cooling. This program will investigate new classes of acoustic levitation in rectangular, cylindrical and spherical geometries. The program tasks include calculating theoretical expressions of the acoustic forces in these geometries for the excitation of up to three acoustic modes (multimodes). These calculations are used to: (1) determine those acoustic modes that produce stable levitation, (2) isolate the levitation and rotation capabilities to produce more than one axis of rotation, and (3) develop methods to translate samples down long tube cylindrical chambers. Experimental levitators will then be constructed to verify the stable levitation and rotation predictions of the models.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Predator Stress-Induced CRF Release Causes Enduring Sensitization of Basolateral Amygdala Norepinephrine Systems that Promote PTSD-Like Startle Abnormalities

    PubMed Central

    Rajbhandari, Abha K.

    2015-01-01

    The neurobiology of post-traumatic stress disorder (PTSD) remains unclear. Intense stress promotes PTSD, which has been associated with exaggerated startle and deficient sensorimotor gating. Here, we examined the long-term sequelae of a rodent model of traumatic stress (repeated predator exposure) on amygdala systems that modulate startle and prepulse inhibition (PPI), an operational measure of sensorimotor gating. We show in rodents that repeated psychogenic stress (predator) induces long-lasting sensitization of basolateral amygdala (BLA) noradrenergic (NE) receptors (α1) via a corticotropin-releasing factor receptor 1 (CRF-R1)-dependent mechanism, and that these CRF1 and NE α1 receptors are highly colocalized on presumptive excitatory output projection neurons of the BLA. A profile identical to that seen with predator exposure was produced in nonstressed rats by intra-BLA infusions of CRF (200 ng/0.5 μl), but not by repeated NE infusions (20 μg/0.5 μl). Infusions into the adjacent central nucleus of amygdala had no effect. Importantly, the predator stress- or CRF-induced sensitization of BLA manifested as heightened startle and PPI deficits in response to subsequent subthreshold NE system challenges (with intra-BLA infusions of 0.3 μg/0.5 μl NE), up to 1 month after stress. This profile of effects closely resembles aspects of PTSD. Hence, we reveal a discrete neural pathway mediating the enhancement of NE system function seen in PTSD, and we offer a model for characterizing potential new treatments that may work by modulating this BLA circuitry. SIGNIFICANCE STATEMENT The present findings reveal a novel and discrete neural substrate that could underlie certain core deficits (startle and prepulse inhibition) that are observed in post-traumatic stress disorder (PTSD). It is shown here that repeated exposure to a rodent model of traumatic stress (predator exposure) produces a long-lasting sensitization of basolateral amygdala noradrenergic substrates [via a

  3. Stimuli-Responsive Materials for Controlled Release of Theranostic Agents

    PubMed Central

    Wang, Yucai; Shim, Min Suk; Levinson, Nathanael S.; Sung, Hsing-Wen

    2014-01-01

    Stimuli-responsive materials are so named because they can alter their physicochemical properties and/or structural conformations in response to specific stimuli. The stimuli can be internal, such as physiological or pathological variations in the target cells/tissues, or external, such as optical and ultrasound radiations. In recent years, these materials have gained increasing interest in biomedical applications due to their potential for spatially and temporally controlled release of theranostic agents in response to the specific stimuli. This article highlights several recent advances in the development of such materials, with a focus on their molecular designs and formulations. The future of stimuli-responsive materials will also be explored, including combination with molecular imaging probes and targeting moieties, which could enable simultaneous diagnosis and treatment of a specific disease, as well as multi-functionality and responsiveness to multiple stimuli, all important in overcoming intrinsic biological barriers and increasing clinical viability. PMID:25477774

  4. Gating of attention towards food stimuli in binge eating disorder.

    PubMed

    Schmitz, Florian; Naumann, Eva; Biehl, Stefanie; Svaldi, Jennifer

    2015-12-01

    Cognitive models of eating disorders propose that attentional biases for disorder-relevant stimuli contribute to eating disorder pathology. Empirical evidence of a contribution of attentional biases for binge eating disorder (BED) is still scarce. The aim of the present study was to assess attention engagement towards, and disengagement from, food stimuli in overweight females with BED (n = 25) and a group of overweight and obese women without BED (OW; n = 30). Participants completed a rapid serial visual presentation (RSVP) paradigm with food and neutral words as target stimuli. This task can be used to decompose an attentional bias for food stimuli into its stimulus engagement and stimulus disengagement components. Findings indicate that facilitated stimulus engagement for food stimuli over neutral stimuli was more pronounced in the BED group compared to the OW group. Conversely, there were no substantial disengagement effects in either group. Thereby, results support the idea that early attentional processes are biased in BED.

  5. Gating of attention towards food stimuli in binge eating disorder.

    PubMed

    Schmitz, Florian; Naumann, Eva; Biehl, Stefanie; Svaldi, Jennifer

    2015-12-01

    Cognitive models of eating disorders propose that attentional biases for disorder-relevant stimuli contribute to eating disorder pathology. Empirical evidence of a contribution of attentional biases for binge eating disorder (BED) is still scarce. The aim of the present study was to assess attention engagement towards, and disengagement from, food stimuli in overweight females with BED (n = 25) and a group of overweight and obese women without BED (OW; n = 30). Participants completed a rapid serial visual presentation (RSVP) paradigm with food and neutral words as target stimuli. This task can be used to decompose an attentional bias for food stimuli into its stimulus engagement and stimulus disengagement components. Findings indicate that facilitated stimulus engagement for food stimuli over neutral stimuli was more pronounced in the BED group compared to the OW group. Conversely, there were no substantial disengagement effects in either group. Thereby, results support the idea that early attentional processes are biased in BED. PMID:26212270

  6. Acoustic detection of pneumothorax

    NASA Astrophysics Data System (ADS)

    Mansy, Hansen A.; Royston, Thomas J.; Balk, Robert A.; Sandler, Richard H.

    2003-04-01

    This study aims at investigating the feasibility of using low-frequency (<2000 Hz) acoustic methods for medical diagnosis. Several candidate methods of pneumothorax detection were tested in dogs. In the first approach, broadband acoustic signals were introduced into the trachea during end-expiration and transmitted waves were measured at the chest surface. Pneumothorax was found to consistently decrease pulmonary acoustic transmission in the 200-1200-Hz frequency band, while less change was observed at lower frequencies (p<0.0001). The ratio of acoustic energy between low (<220 Hz) and mid (550-770 Hz) frequency bands was significantly different in the control (healthy) and pneumothorax states (p<0.0001). The second approach measured breath sounds in the absence of an external acoustic input. Pneumothorax was found to be associated with a preferential reduction of sound amplitude in the 200- to 700-Hz range, and a decrease of sound amplitude variation (in the 300 to 600-Hz band) during the respiration cycle (p<0.01 for each). Finally, chest percussion was implemented. Pneumothorax changed the frequency and decay rate of percussive sounds. These results imply that certain medical conditions may be reliably detected using appropriate acoustic measurements and analysis. [Work supported by NIH/NHLBI #R44HL61108.

  7. 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. PMID:26723303

  8. 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.

  9. A compact acoustic recorder

    NASA Astrophysics Data System (ADS)

    Stein, Ronald

    1989-09-01

    The design and operation of a portable compact acoustic recorder is discussed. Designed to be used in arctic conditions for applications that require portable equipment, the device is configured to fit into a lightweight briefcase. It will operate for eight hours at -40 F with heat provided by a hot water bottle. It has proven to be an effective scientific tool in the measurement of underwater acoustic signals in arctic experiments. It has also been used successfully in warmer climates, e.g., in recording acoustic signals from small boats with no ac power. The acoustic recorder's cost is moderate since it is based on a Sony Walkman Professional (WM-D6C) tape recorder playback unit. A speaker and battery assembly and a hydrophone interface electronic assembly complete the system electronics. The interface assembly supplies a number of functions, including a calibration tone generator, an audio amplifier, and a hydrophone interface. Calibrated acoustic recordings can be made by comparing the calibration tone amplitude with the acoustic signal amplitude. The distortion of the recording is minimized by using a high quality, consumer tape recorder.

  10. Acoustic communication by ants

    NASA Astrophysics Data System (ADS)

    Hickling, Robert

    2002-05-01

    Many ant species communicate acoustically by stridulating, i.e., running a scraper over a washboard-like set of ridges. Ants appear to be insensitive to airborne sound. Consequently, myrmecologists have concluded that the stridulatory signals are transmitted through the substrate. This has tended to diminish the importance of acoustic communication, and it is currently believed that ant communication is based almost exclusively on pheromones, with acoustic communication assigned an almost nonexistent role. However, it can be shown that acoustic communication between ants is effective only if the medium is air and not the substrate. How, then, is it possible for ants to appear deaf to airborne sound and yet communicate through the air? An explanation is provided in a paper [R. Hickling and R. L. Brown, ``Analysis of acoustic communication by ants,'' J. Acoust. Soc. Am. 108, 1920-1929 (2000)]. Ants are small relative to the wavelengths they generate. Hence, they create a near field, which is characterized by a major increase in sound velocity (particle velocity of sound) in the vicinity of the source. Hair sensilla on the ants' antennae respond to sound velocity. Thus, ants are able to detect near-field sound from other ants and to exclude extraneous airborne sound.

  11. Invisible visual stimuli elicit increases in alpha-band power.

    PubMed

    Bareither, Isabelle; Chaumon, Maximilien; Bernasconi, Fosco; Villringer, Arno; Busch, Niko A

    2014-09-01

    The cerebral cortex responds to stimuli of a wide range of intensities. Previous studies have demonstrated that undetectably weak somatosensory stimuli cause a functional deactivation or inhibition in somatosensory cortex. In the present study, we tested whether invisible visual stimuli lead to similar responses, indicated by an increase in EEG alpha-band power-an index of cortical excitability. We presented subliminal and supraliminal visual stimuli after estimating each participant's detection threshold. Stimuli consisted of peripherally presented small circular patches that differed in their contrast to a background consisting of a random white noise pattern. We demonstrate that subliminal and supraliminal stimuli each elicit specific neuronal response patterns. Supraliminal stimuli evoked an early, strongly phase-locked lower-frequency response representing the evoked potential and induced a decrease in alpha-band power from 400 ms on. By contrast, subliminal visual stimuli induced an increase of non-phase-locked power around 300 ms that was maximal within the alpha-band. This response might be due to an inhibitory mechanism, which reduces spurious visual activation that is unlikely to result from external stimuli. PMID:24872526

  12. Multi-Stimuli Responsive Macromolecules and Their Assemblies

    PubMed Central

    Zhuang, Jiaming; Gordon, Mallory; Ventura, Judy; Li, Longyu; Thayumanavan, S.

    2013-01-01

    In this review, we outline examples that illustrate the design criteria for achieving macromolecular assemblies that incorporate a combination of two or more chemical, physical or biological stimuli-responsive components. Progress in both fundamental investigation into the phase transformations of these polymers in response to multiple stimuli and their utilization in a variety of pratical applications have been highlighted. Using these examples, we aim to explain the origin of employed mechanisms of stimuli responsiveness which may serve as a guideline to inspire future design of multi-stimuli responsive materials. PMID:23765263

  13. Invisible visual stimuli elicit increases in alpha-band power.

    PubMed

    Bareither, Isabelle; Chaumon, Maximilien; Bernasconi, Fosco; Villringer, Arno; Busch, Niko A

    2014-09-01

    The cerebral cortex responds to stimuli of a wide range of intensities. Previous studies have demonstrated that undetectably weak somatosensory stimuli cause a functional deactivation or inhibition in somatosensory cortex. In the present study, we tested whether invisible visual stimuli lead to similar responses, indicated by an increase in EEG alpha-band power-an index of cortical excitability. We presented subliminal and supraliminal visual stimuli after estimating each participant's detection threshold. Stimuli consisted of peripherally presented small circular patches that differed in their contrast to a background consisting of a random white noise pattern. We demonstrate that subliminal and supraliminal stimuli each elicit specific neuronal response patterns. Supraliminal stimuli evoked an early, strongly phase-locked lower-frequency response representing the evoked potential and induced a decrease in alpha-band power from 400 ms on. By contrast, subliminal visual stimuli induced an increase of non-phase-locked power around 300 ms that was maximal within the alpha-band. This response might be due to an inhibitory mechanism, which reduces spurious visual activation that is unlikely to result from external stimuli.

  14. Predator and heterospecific stimuli alter behaviour in cattle.

    PubMed

    Kluever, Bryan M; Howery, Larry D; Breck, Stewart W; Bergman, David L

    2009-05-01

    Wild and domestic ungulates modify their behaviour in the presence of olfactory and visual cues of predators but investigations have not exposed a domestic species to a series of cues representing various predators and other ungulate herbivores. We used wolf (Canis lupus), mountain lion (Puma concolor), and mule deer (Odocoileus hemionus) stimuli (olfactory and visual), and a control (no stimuli) to experimentally test for differences in behaviour of cattle (Bos taurus) raised in Arizona. We measured (1) vigilance, (2) foraging rates, (3) giving up density (GUD) of high quality foods and (4) time spent in high quality forage locations in response to location of stimuli treatments. In general, we found a consistent pattern in that wolf and deer treatments caused disparate results in all 4 response variables. Wolf stimuli significantly increased cattle vigilance and decreased cattle foraging rates; conversely, deer stimuli significantly increased cattle foraging rate and increased cattle use of high quality forage areas containing stimuli. Mountain lion stimuli did not significantly impact any of the 4 response variables. Our findings suggest that domestic herbivores react to predatory stimuli, can differentiate between stimuli representing two predatory species, and suggest that cattle may reduce antipredatory behaviour when near heterospecifics. PMID:19429201

  15. Auditory evoked potentials in the auditory system of a beluga whale Delphinapterus leucas to prolonged sound stimuli.

    PubMed

    Popov, Vladimir V; Sysueva, Evgenia V; Nechaev, Dmitry I; Rozhnov, Vyatcheslav V; Supin, Alexander Ya

    2016-03-01

    The effects of prolonged (up to 1500 s) sound stimuli (tone pip trains) on evoked potentials (the rate following response, RFR) were investigated in a beluga whale. The stimuli (rhythmic tone pips) were of frequencies of 45, 64, and 90 kHz at levels from 20 to 60 dB above threshold. Two experimental protocols were used: short- and long-duration. For the short-duration protocol, the stimuli were 500-ms-long pip trains that repeated at a rate of 0.4 trains/s. For the long-duration protocol, the stimuli were continuous pip successions lasting up to 1500 s. The RFR amplitude gradually decreased by three to seven times from 10 ms to 1500 s of stimulation. Decrease of response amplitude during stimulation was approximately proportional to initial (at the start of stimulation) response amplitude. Therefore, even for low stimulus level (down to 20 dB above the baseline threshold) the response was never suppressed completely. The RFR amplitude decay that occurred during stimulation could be satisfactorily approximated by a combination of two exponents with time constants of 30-80 ms and 3.1-17.6 s. The role of adaptation in the described effects and the impact of noise on the acoustic orientation of odontocetes are discussed.

  16. Processing of pure-tone and FM stimuli in the auditory cortex of the FM bat, Myotis lucifugus.

    PubMed

    Shannon-Hartman, S; Wong, D; Maekawa, M

    1992-08-01

    FM bats perceive their surroundings during echolocation by analyzing frequency-modulated (FM) acoustic signals. Results from this study indicate a cortical organization in Myotis lucifugus which is largely made up of neurons sensitive to FM sounds (FM-sensitive neurons). Three types of neurons were distinguished by their responses to pure-tone and FM stimuli: (1) Type I FM-sensitive units (83%), Type II FM-sensitive units (13%) and pure-tone sensitive units (4%). Type I FM-sensitive units responded to pure tones, but exhibited greater response magnitudes to FM stimuli when the best FM swept through the BF. An orderly frequency representation was found when the frequencies of pure tones essential for response (EPTs) in Type I units were mapped along the cortical surface. The EPTs for Type I neurons were usually found within the last millisecond of a downward FM sweep. As outlined by two neuronal network models, both the responses of Type I and II units could likely result from the convergence of excitatory and inhibitory lower level neurons with slightly differing BFs. Type II units were selective for an FM sweep and showed negligible to no response to pure-tone stimuli. Pure-tone sensitive units exhibited weak or no responses to FM stimuli. These neurons were clustered in a small area located rostrodorsal to the tonotopic zone and had significantly lower best frequencies than adjacent EPT frequencies of Type I FM-sensitive neurons. PMID:1326505

  17. Auditory evoked potentials in the auditory system of a beluga whale Delphinapterus leucas to prolonged sound stimuli.

    PubMed

    Popov, Vladimir V; Sysueva, Evgenia V; Nechaev, Dmitry I; Rozhnov, Vyatcheslav V; Supin, Alexander Ya

    2016-03-01

    The effects of prolonged (up to 1500 s) sound stimuli (tone pip trains) on evoked potentials (the rate following response, RFR) were investigated in a beluga whale. The stimuli (rhythmic tone pips) were of frequencies of 45, 64, and 90 kHz at levels from 20 to 60 dB above threshold. Two experimental protocols were used: short- and long-duration. For the short-duration protocol, the stimuli were 500-ms-long pip trains that repeated at a rate of 0.4 trains/s. For the long-duration protocol, the stimuli were continuous pip successions lasting up to 1500 s. The RFR amplitude gradually decreased by three to seven times from 10 ms to 1500 s of stimulation. Decrease of response amplitude during stimulation was approximately proportional to initial (at the start of stimulation) response amplitude. Therefore, even for low stimulus level (down to 20 dB above the baseline threshold) the response was never suppressed completely. The RFR amplitude decay that occurred during stimulation could be satisfactorily approximated by a combination of two exponents with time constants of 30-80 ms and 3.1-17.6 s. The role of adaptation in the described effects and the impact of noise on the acoustic orientation of odontocetes are discussed. PMID:27036247

  18. Hearing tongue loops: Perceptual sensitivity to acoustic signatures of articulatory dynamics

    PubMed Central

    Nam, Hosung; Mooshammer, Christine; Iskarous, Khalil; Whalen, D. H.

    2013-01-01

    Previous work has shown that velar stops are produced with a forward movement during closure, forming a forward (anterior) loop for a VCV sequence, when the preceding vowels are back or mid. Are listeners aware of this aspect of articulatory dynamics? The current study used articulatory synthesis to examine how such kinematic patterns are reflected in the acoustics, and whether those acoustic patterns elicit different goodness ratings. In Experiment I, the size and direction of loops was modulated in articulatory synthesis. The resulting stimuli were presented to listeners for a naturalness judgment. Results show that listeners rate forward loops as more natural than backward loops, in agreement with typical productions. Acoustic analysis of the synthetic stimuli shows that forward loops exhibit shorter and shallower VC transitions than CV transitions. In Experiment II, three acoustic parameters were employed incorporating F3-F2 distance, transition slope, and transition length to systematically modulate the magnitude of VC and CV transitions. Listeners rated the naturalness in accord with those of Experiment I. This study reveals that there is sufficient information in the acoustic signature of “velar loops” to affect perceptual preference. Similarity to typical productions seemed to determine preferences, not acoustic distinctiveness. PMID:24180790

  19. A Corticosteroid-Responsive Transcription Factor, Promyelocytic Leukemia Zinc Finger Protein, Mediates Protection of the Cochlea from Acoustic Trauma

    PubMed Central

    Peppi, Marcello; Kujawa, Sharon G.; Sewell, William F.

    2012-01-01

    Animals can be induced to resist cochlear damage associated with acoustic trauma by exposure to a variety of “conditioning” stimuli, including restraint stress, moderate level sound, heat stress, hypoxia, and corticosteroids. Here we identify in mice a corticosteroid-responsive transcription factor, PLZF (promyelocytic leukemia zinc finger protein), which mediates conditioned protection of the cochlea from acoustic trauma. PLZF mRNA levels in the cochlea are increased following conditioning stimuli, including restraint stress, dexamethasone administration, and moderate-to-high level acoustic stimulation. Heterozygous mutant (luxoid.Zbtb16LU/J) mice deficient in PLZF have hearing and responses to acoustic trauma similar to their wild type littermates but are unable to generate conditioning-induced protection from acoustic trauma. PLZF immunoreactivity is present in the spiral ganglion, lateral wall of the cochlea, and organ of Corti, all targets for acoustic trauma. PLZF is also present in the brain and PLZF mRNA in brain is elevated following conditioning stimuli. The identification of a transcription factor that mediates conditioned protection from trauma provides a tool for understanding the protective action of corticosteroids, which are widely used in treating acute hearing loss, and has relevance to understanding the role of corticosteroids in trauma protection. PMID:21228182

  20. Happiness increases distraction by auditory deviant stimuli.

    PubMed

    Pacheco-Unguetti, Antonia Pilar; Parmentier, Fabrice B R

    2016-08-01

    Rare and unexpected changes (deviants) in an otherwise repeated stream of task-irrelevant auditory distractors (standards) capture attention and impair behavioural performance in an ongoing visual task. Recent evidence indicates that this effect is increased by sadness in a task involving neutral stimuli. We tested the hypothesis that such effect may not be limited to negative emotions but reflect a general depletion of attentional resources by examining whether a positive emotion (happiness) would increase deviance distraction too. Prior to performing an auditory-visual oddball task, happiness or a neutral mood was induced in participants by means of the exposure to music and the recollection of an autobiographical event. Results from the oddball task showed significantly larger deviance distraction following the induction of happiness. Interestingly, the small amount of distraction typically observed on the standard trial following a deviant trial (post-deviance distraction) was not increased by happiness. We speculate that happiness might interfere with the disengagement of attention from the deviant sound back towards the target stimulus (through the depletion of cognitive resources and/or mind wandering) but help subsequent cognitive control to recover from distraction. PMID:26302716

  1. Happiness increases distraction by auditory deviant stimuli.

    PubMed

    Pacheco-Unguetti, Antonia Pilar; Parmentier, Fabrice B R

    2016-08-01

    Rare and unexpected changes (deviants) in an otherwise repeated stream of task-irrelevant auditory distractors (standards) capture attention and impair behavioural performance in an ongoing visual task. Recent evidence indicates that this effect is increased by sadness in a task involving neutral stimuli. We tested the hypothesis that such effect may not be limited to negative emotions but reflect a general depletion of attentional resources by examining whether a positive emotion (happiness) would increase deviance distraction too. Prior to performing an auditory-visual oddball task, happiness or a neutral mood was induced in participants by means of the exposure to music and the recollection of an autobiographical event. Results from the oddball task showed significantly larger deviance distraction following the induction of happiness. Interestingly, the small amount of distraction typically observed on the standard trial following a deviant trial (post-deviance distraction) was not increased by happiness. We speculate that happiness might interfere with the disengagement of attention from the deviant sound back towards the target stimulus (through the depletion of cognitive resources and/or mind wandering) but help subsequent cognitive control to recover from distraction.

  2. Stereotypic vision: how stereotypes disambiguate visual stimuli.

    PubMed

    Correll, Joshua; Wittenbrink, Bernd; Crawford, Matthew T; Sadler, Melody S

    2015-02-01

    Three studies examined how participants use race to disambiguate visual stimuli. Participants performed a first-person-shooter task in which Black and White targets appeared holding either a gun or an innocuous object (e.g., a wallet). In Study 1, diffusion analysis (Ratcliff, 1978) showed that participants rapidly acquired information about a gun when it appeared in the hands of a Black target, and about an innocuous object in the hands of a White target. For counterstereotypic pairings (armed Whites, unarmed Blacks), participants acquired information more slowly. In Study 2, eye tracking showed that participants relied on more ambiguous information (measured by visual angle from fovea) when responding to stereotypic targets; for counterstereotypic targets, they achieved greater clarity before responding. In Study 3, participants were briefly exposed to targets (limiting access to visual information) but had unlimited time to respond. In spite of their slow, deliberative responses, they showed racial bias. This pattern is inconsistent with control failure and suggests that stereotypes influenced identification of the object. All 3 studies show that race affects visual processing by supplementing objective information. PMID:25603373

  3. Anchoring in Numeric Judgments of Visual Stimuli

    PubMed Central

    Langeborg, Linda; Eriksson, Mårten

    2016-01-01

    This article investigates effects of anchoring in age estimation and estimation of quantities, two tasks which to different extents are based on visual stimuli. The results are compared to anchoring in answers to classic general knowledge questions that rely on semantic knowledge. Cognitive load was manipulated to explore possible differences between domains. Effects of source credibility, manipulated by differing instructions regarding the selection of anchor values (no information regarding anchor selection, information that the anchors are randomly generated or information that the anchors are answers from an expert) on anchoring were also investigated. Effects of anchoring were large for all types of judgments but were not affected by cognitive load or by source credibility in either one of the researched domains. A main effect of cognitive load on quantity estimations and main effects of source credibility in the two visually based domains indicate that the manipulations were efficient. Implications for theoretical explanations of anchoring are discussed. In particular, because anchoring did not interact with cognitive load, the results imply that the process behind anchoring in visual tasks is predominantly automatic and unconscious. PMID:26941684

  4. Anchoring in Numeric Judgments of Visual Stimuli.

    PubMed

    Langeborg, Linda; Eriksson, Mårten

    2016-01-01

    This article investigates effects of anchoring in age estimation and estimation of quantities, two tasks which to different extents are based on visual stimuli. The results are compared to anchoring in answers to classic general knowledge questions that rely on semantic knowledge. Cognitive load was manipulated to explore possible differences between domains. Effects of source credibility, manipulated by differing instructions regarding the selection of anchor values (no information regarding anchor selection, information that the anchors are randomly generated or information that the anchors are answers from an expert) on anchoring were also investigated. Effects of anchoring were large for all types of judgments but were not affected by cognitive load or by source credibility in either one of the researched domains. A main effect of cognitive load on quantity estimations and main effects of source credibility in the two visually based domains indicate that the manipulations were efficient. Implications for theoretical explanations of anchoring are discussed. In particular, because anchoring did not interact with cognitive load, the results imply that the process behind anchoring in visual tasks is predominantly automatic and unconscious. PMID:26941684

  5. Anchoring in Numeric Judgments of Visual Stimuli.

    PubMed

    Langeborg, Linda; Eriksson, Mårten

    2016-01-01

    This article investigates effects of anchoring in age estimation and estimation of quantities, two tasks which to different extents are based on visual stimuli. The results are compared to anchoring in answers to classic general knowledge questions that rely on semantic knowledge. Cognitive load was manipulated to explore possible differences between domains. Effects of source credibility, manipulated by differing instructions regarding the selection of anchor values (no information regarding anchor selection, information that the anchors are randomly generated or information that the anchors are answers from an expert) on anchoring were also investigated. Effects of anchoring were large for all types of judgments but were not affected by cognitive load or by source credibility in either one of the researched domains. A main effect of cognitive load on quantity estimations and main effects of source credibility in the two visually based domains indicate that the manipulations were efficient. Implications for theoretical explanations of anchoring are discussed. In particular, because anchoring did not interact with cognitive load, the results imply that the process behind anchoring in visual tasks is predominantly automatic and unconscious.

  6. Stereotypic vision: how stereotypes disambiguate visual stimuli.

    PubMed

    Correll, Joshua; Wittenbrink, Bernd; Crawford, Matthew T; Sadler, Melody S

    2015-02-01

    Three studies examined how participants use race to disambiguate visual stimuli. Participants performed a first-person-shooter task in which Black and White targets appeared holding either a gun or an innocuous object (e.g., a wallet). In Study 1, diffusion analysis (Ratcliff, 1978) showed that participants rapidly acquired information about a gun when it appeared in the hands of a Black target, and about an innocuous object in the hands of a White target. For counterstereotypic pairings (armed Whites, unarmed Blacks), participants acquired information more slowly. In Study 2, eye tracking showed that participants relied on more ambiguous information (measured by visual angle from fovea) when responding to stereotypic targets; for counterstereotypic targets, they achieved greater clarity before responding. In Study 3, participants were briefly exposed to targets (limiting access to visual information) but had unlimited time to respond. In spite of their slow, deliberative responses, they showed racial bias. This pattern is inconsistent with control failure and suggests that stereotypes influenced identification of the object. All 3 studies show that race affects visual processing by supplementing objective information.

  7. Fingertip skin-inspired microstructured ferroelectric skins discriminate static/dynamic pressure and temperature stimuli.

    PubMed

    Park, Jonghwa; Kim, Marie; Lee, Youngoh; Lee, Heon Sang; Ko, Hyunhyub

    2015-10-01

    In human fingertips, the fingerprint patterns and interlocked epidermal-dermal microridges play a critical role in amplifying and transferring tactile signals to various mechanoreceptors, enabling spatiotemporal perception of various static and dynamic tactile signals. Inspired by the structure and functions of the human fingertip, we fabricated fingerprint-like patterns and interlocked microstructures in ferroelectric films, which can enhance the piezoelectric, pyroelectric, and piezoresistive sensing of static and dynamic mechanothermal signals. Our flexible and microstructured ferroelectric skins can detect and discriminate between multiple spatiotemporal tactile stimuli including static and dynamic pressure, vibration, and temperature with high sensitivities. As proof-of-concept demonstration, the sensors have been used for the simultaneous monitoring of pulse pressure and temperature of artery vessels, precise detection of acoustic sounds, and discrimination of various surface textures. Our microstructured ferroelectric skins may find applications in robotic skins, wearable sensors, and medical diagnostic devices.

  8. Fingertip skin–inspired microstructured ferroelectric skins discriminate static/dynamic pressure and temperature stimuli

    PubMed Central

    Park, Jonghwa; Kim, Marie; Lee, Youngoh; Lee, Heon Sang; Ko, Hyunhyub

    2015-01-01

    In human fingertips, the fingerprint patterns and interlocked epidermal-dermal microridges play a critical role in amplifying and transferring tactile signals to various mechanoreceptors, enabling spatiotemporal perception of various static and dynamic tactile signals. Inspired by the structure and functions of the human fingertip, we fabricated fingerprint-like patterns and interlocked microstructures in ferroelectric films, which can enhance the piezoelectric, pyroelectric, and piezoresistive sensing of static and dynamic mechanothermal signals. Our flexible and microstructured ferroelectric skins can detect and discriminate between multiple spatiotemporal tactile stimuli including static and dynamic pressure, vibration, and temperature with high sensitivities. As proof-of-concept demonstration, the sensors have been used for the simultaneous monitoring of pulse pressure and temperature of artery vessels, precise detection of acoustic sounds, and discrimination of various surface textures. Our microstructured ferroelectric skins may find applications in robotic skins, wearable sensors, and medical diagnostic devices. PMID:26601303

  9. Fingertip skin-inspired microstructured ferroelectric skins discriminate static/dynamic pressure and temperature stimuli.

    PubMed

    Park, Jonghwa; Kim, Marie; Lee, Youngoh; Lee, Heon Sang; Ko, Hyunhyub

    2015-10-01

    In human fingertips, the fingerprint patterns and interlocked epidermal-dermal microridges play a critical role in amplifying and transferring tactile signals to various mechanoreceptors, enabling spatiotemporal perception of various static and dynamic tactile signals. Inspired by the structure and functions of the human fingertip, we fabricated fingerprint-like patterns and interlocked microstructures in ferroelectric films, which can enhance the piezoelectric, pyroelectric, and piezoresistive sensing of static and dynamic mechanothermal signals. Our flexible and microstructured ferroelectric skins can detect and discriminate between multiple spatiotemporal tactile stimuli including static and dynamic pressure, vibration, and temperature with high sensitivities. As proof-of-concept demonstration, the sensors have been used for the simultaneous monitoring of pulse pressure and temperature of artery vessels, precise detection of acoustic sounds, and discrimination of various surface textures. Our microstructured ferroelectric skins may find applications in robotic skins, wearable sensors, and medical diagnostic devices. PMID:26601303

  10. Direct Intracochlear Acoustic Stimulation Using a PZT Microactuator.

    PubMed

    Luo, Chuan; Omelchenko, Irina; Manson, Robert; Robbins, Carol; Oesterle, Elizabeth C; Cao, Guo Zhong; Shen, I Y; Hume, Clifford R

    2015-01-01

    Combined electric and acoustic stimulation has proven to be an effective strategy to improve hearing in some cochlear implant users. We describe an acoustic microactuator to directly deliver stimuli to the perilymph in the scala tympani. The 800 µm by 800 µm actuator has a silicon diaphragm driven by a piezoelectric thin film (e.g., lead-zirconium-titanium oxide or PZT). This device could also be used as a component of a bimodal acoustic-electric electrode array. In the current study, we established a guinea pig model to test the actuator for its ability to deliver auditory signals to the cochlea in vivo. The actuator was placed through the round window of the cochlea. Auditory brainstem response (ABR) thresholds, peak latencies, and amplitude growth were calculated for an ear canal speaker versus the intracochlear actuator for tone burst stimuli at 4, 8, 16, and 24 kHz. An ABR was obtained after removal of the probe to assess loss of hearing related to the procedure. In some animals, the temporal bone was harvested for histologic analysis of cochlear damage. We show that the device is capable of stimulating ABRs in vivo with latencies and growth functions comparable to stimulation in the ear canal. Further experiments will be necessary to evaluate the efficiency and safety of this modality in long-term auditory stimulation and its ability to be integrated with conventional cochlear implant arrays. PMID:26631107

  11. Direct Intracochlear Acoustic Stimulation Using a PZT Microactuator

    PubMed Central

    Luo, Chuan; Omelchenko, Irina; Manson, Robert; Robbins, Carol; Oesterle, Elizabeth C.; Cao, Guo Zhong; Hume, Clifford R.

    2015-01-01

    Combined electric and acoustic stimulation has proven to be an effective strategy to improve hearing in some cochlear implant users. We describe an acoustic microactuator to directly deliver stimuli to the perilymph in the scala tympani. The 800 µm by 800 µm actuator has a silicon diaphragm driven by a piezoelectric thin film (e.g., lead-zirconium-titanium oxide or PZT). This device could also be used as a component of a bimodal acoustic-electric electrode array. In the current study, we established a guinea pig model to test the actuator for its ability to deliver auditory signals to the cochlea in vivo. The actuator was placed through the round window of the cochlea. Auditory brainstem response (ABR) thresholds, peak latencies, and amplitude growth were calculated for an ear canal speaker versus the intracochlear actuator for tone burst stimuli at 4, 8, 16, and 24 kHz. An ABR was obtained after removal of the probe to assess loss of hearing related to the procedure. In some animals, the temporal bone was harvested for histologic analysis of cochlear damage. We show that the device is capable of stimulating ABRs in vivo with latencies and growth functions comparable to stimulation in the ear canal. Further experiments will be necessary to evaluate the efficiency and safety of this modality in long-term auditory stimulation and its ability to be integrated with conventional cochlear implant arrays. PMID:26631107

  12. 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

  13. Acoustic Imaging in Helioseismology

    NASA Astrophysics Data System (ADS)

    Chou, Dean-Yi; Chang, Hsiang-Kuang; Sun, Ming-Tsung; LaBonte, Barry; Chen, Huei-Ru; Yeh, Sheng-Jen; Team, The TON

    1999-04-01

    The time-variant acoustic signal at a point in the solar interior can be constructed from observations at the surface, based on the knowledge of how acoustic waves travel in the Sun: the time-distance relation of the p-modes. The basic principle and properties of this imaging technique are discussed in detail. The helioseismic data used in this study were taken with the Taiwan Oscillation Network (TON). The time series of observed acoustic signals on the solar surface is treated as a phased array. The time-distance relation provides the phase information among the phased array elements. The signal at any location at any time can be reconstructed by summing the observed signal at array elements in phase and with a proper normalization. The time series of the constructed acoustic signal contains information on frequency, phase, and intensity. We use the constructed intensity to obtain three-dimensional acoustic absorption images. The features in the absorption images correlate with the magnetic field in the active region. The vertical extension of absorption features in the active region is smaller in images constructed with shorter wavelengths. This indicates that the vertical resolution of the three-dimensional images depends on the range of modes used in constructing the signal. The actual depths of the absorption features in the active region may be smaller than those shown in the three-dimensional images.

  14. [Acoustic characteristics of classrooms].

    PubMed

    Koszarny, Zbigniew; Chyla, Andrzej

    2003-01-01

    Quality and usefulness of school rooms for transmission of verbal information depends on the two basic parameters: form and quantity of the reverberation time, and profitable line measurements of school rooms from the acoustic point of view. An analysis of the above-mentioned parameters in 48 class rooms and two gymnasiums in schools, which were built in different periods, shows that the most important problem is connected with too long reverberation time and inappropriate acoustic proportions. In schools built in the 1970s, the length of reverberation time is mostly within a low frequency band, while in schools built contemporarily, the maximum length of disappearance time takes place in a quite wide band of 250-2000 Hz. This exceeds optimal values for that kind of rooms at least twice, and five times in the newly built school. A long reverberation time is connected with a low acoustic absorption of school rooms. Moreover, school rooms are characterised by inappropriate acoustic proportions. The classrooms, in their relation to the height, are too long and too wide. It is connected with deterioration of the transmission of verbal information. The data show that this transmission is unequal. Automatically, it leads to a speech disturbance and difficulties with understanding. There is the need for adaptation of school rooms through increase of an acoustic absorption.

  15. 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.

  16. Exploring Visuomotor Priming Following Biological and Non-Biological Stimuli

    ERIC Educational Resources Information Center

    Gowen, E.; Bradshaw, C.; Galpin, A.; Lawrence, A.; Poliakoff, E.

    2010-01-01

    Observation of human actions influences the observer's own motor system, termed visuomotor priming, and is believed to be caused by automatic activation of mirror neurons. Evidence suggests that priming effects are larger for biological (human) as opposed to non-biological (object) stimuli and enhanced when viewing stimuli in mirror compared to…

  17. Inhibition of premature ventricular extrastimuli by subthreshold conditioning stimuli.

    PubMed

    Skale, B T; Kallok, M J; Prystowsky, E N; Gill, R M; Zipes, D P

    1985-07-01

    The purpose of this study was to determine whether trains of subthreshold high frequency conditioning stimuli (333 Hz, 1 ms duration, 2 ms interval) delivered to the canine ventricle inhibited the response to a premature stimulus (S2) more effectively than did a single subthreshold conditioning stimulus. It was found that trains of conditioning stimuli (mean 1.21 mA) inhibited the response to S2 152 ms beyond expiration of the ventricular effective refractory period, whereas a single conditioning stimulus inhibited S2 only 20 ms or less beyond the ventricular effective refractory period. In late diastole, trains of conditioning stimuli failed to inhibit S2 when the train of stimuli caused ventricular depolarization or the latter occurred in response to the next sinus impulse. Trains of conditioning stimuli did not induce ventricular arrhythmias. Lidocaine or autonomic blockade did not alter the response to trains of conditioning stimuli. Trains of conditioning stimuli or a single conditioning stimulus inhibited the response to S2 only when they were delivered at the same electrode site. By lengthening the ventricular effective refractory period, trains of conditioning stimuli could prevent or terminate tachycardias, but this possibility is constrained, at present, by the spatial limitations of the technique.

  18. Conditional Reinforcers and Informative Stimuli in a Constant Environment

    ERIC Educational Resources Information Center

    Boutros, Nathalie; Davison, Michael; Elliffe, Douglas

    2009-01-01

    Five pigeons responded on steady-state concurrent variable-interval variable-interval schedules of food presentation in which half of the foods were removed and replaced with nonfood stimuli. Across conditions, the stimuli were either paired or unpaired with food, and the correlation between the ratio of food deliveries on the two alternatives and…

  19. Freeze or Flee? Negative Stimuli Elicit Selective Responding

    ERIC Educational Resources Information Center

    Estes, Zachary; Verges, Michelle

    2008-01-01

    Humans preferentially attend to negative stimuli. A consequence of this automatic vigilance for negative valence is that negative words elicit slower responses than neutral or positive words on a host of cognitive tasks. Some researchers have speculated that negative stimuli elicit a general suppression of motor activity, akin to the freezing…

  20. Logical Rules and the Classification of Integral-Dimension Stimuli

    ERIC Educational Resources Information Center

    Little, Daniel R.; Nosofsky, Robert M.; Donkin, Christopher; Denton, Stephen E.

    2013-01-01

    A classic distinction in perceptual information processing is whether stimuli are composed of separable dimensions, which are highly analyzable, or integral dimensions, which are processed holistically. Previous tests of a set of logical-rule models of classification have shown that separable-dimension stimuli are processed serially if the…

  1. X-ray motion analysis of the vertebral column during the startle response in striped bass, Morone saxatilis.

    PubMed

    Nowroozi, B N; Brainerd, E L

    2013-08-01

    Whole-body stiffness has a substantial impact on propulsive wave speed during axial undulatory locomotion in fishes. The connective tissues of the vertebral column may contribute to body stiffness, but without mechanical and kinematic analysis it is unclear whether the in vivo range of motion of intervertebral joints (IVJs) is great enough to stress IVJ tissues, thus generating stiffness. The present study used 2D videoradiography and 3D X-ray reconstruction of moving morphology (XROMM) to quantify vertebral kinematics during the startle response in striped bass (Morone saxatilis). X-ray video revealed two distinct patterns of bending: pattern I begins in the abdominal region and then proceeds to maximum IVJ angles in the caudal region, whereas pattern II begins in the cervical region and proceeds to maximum IVJ angles in the abdominal and then the caudal joints. In pattern II bends, the cervical joints exhibit a greater in vivo range of motion than previously reported in other species. XROMM analysis of caudal IVJs suggests primarily lateral bending: mean axial and dorsoventral rotations were less than 2 deg and inconsistent across 51 sequences analyzed from five individuals, whereas mean maximum lateral bending angles were 10.4±3.57 deg. These angles, combined with previous investigations of mechanical properties, reveal that the maximum angles all occur within the neutral zone of bending, indicating that little stress is experienced about the joint. This suggests that the IVJs of striped bass are quite compliant and likely do not contribute significantly to whole-body stiffness or elastic recoil during swimming in vivo. PMID:23842627

  2. X-ray motion analysis of the vertebral column during the startle response in striped bass, Morone saxatilis.

    PubMed

    Nowroozi, B N; Brainerd, E L

    2013-08-01

    Whole-body stiffness has a substantial impact on propulsive wave speed during axial undulatory locomotion in fishes. The connective tissues of the vertebral column may contribute to body stiffness, but without mechanical and kinematic analysis it is unclear whether the in vivo range of motion of intervertebral joints (IVJs) is great enough to stress IVJ tissues, thus generating stiffness. The present study used 2D videoradiography and 3D X-ray reconstruction of moving morphology (XROMM) to quantify vertebral kinematics during the startle response in striped bass (Morone saxatilis). X-ray video revealed two distinct patterns of bending: pattern I begins in the abdominal region and then proceeds to maximum IVJ angles in the caudal region, whereas pattern II begins in the cervical region and proceeds to maximum IVJ angles in the abdominal and then the caudal joints. In pattern II bends, the cervical joints exhibit a greater in vivo range of motion than previously reported in other species. XROMM analysis of caudal IVJs suggests primarily lateral bending: mean axial and dorsoventral rotations were less than 2 deg and inconsistent across 51 sequences analyzed from five individuals, whereas mean maximum lateral bending angles were 10.4±3.57 deg. These angles, combined with previous investigations of mechanical properties, reveal that the maximum angles all occur within the neutral zone of bending, indicating that little stress is experienced about the joint. This suggests that the IVJs of striped bass are quite compliant and likely do not contribute significantly to whole-body stiffness or elastic recoil during swimming in vivo.

  3. Violent Reactions from Non-Shock Stimuli

    NASA Astrophysics Data System (ADS)

    Sandusky, Harold

    2007-06-01

    Most reactions are thermally initiated, whether from direct heating or dissipation of energy from mechanical, shock, or electrical stimuli. For other than prompt shock initiation, the reaction must be able to spread through porosity or over large surface area to become more violent than just rupturing any confinement. While burning rates are important, high-strain mechanical properties are nearly so, either by reducing existing porosity or generating additional surface area through fracture. The first example is deflagration-to-detonation transition (DDT) in porous beds. During the early stages, weak compressive waves ahead of the convective ignition front will reduce porosity, thereby restricting the spread of combustion and the pressure buildup. If, however, pressure increases faster than can be relieved by loss of confinement, coalescing compressive waves can initiate reaction at hot spots from rapid pore collapse. This compressive reaction can drive a shockwave that transits to detonation, the most violent reaction in any scenario. It has been shown that reaction violence is reduced in DDT experiments if the binder is softened, either by raising the initial temperature or adding a solvent. An example of the role of mechanical properties in enhancing reaction violence through fracturing occurs when cavities in projectile fills collapse during acceleration in the gun barrel, which is referred to as setback. Explosives with soft rubber binders will deform and undergo mild reaction from shear heating within the explosive and adiabatic compression of any gas in the cavity. Stiff explosives are similarly ignited, but also fracture and generate additional surface area for a violent event. The last example to be considered is slow cook-off, where thermal damage can increase burning rate as well as provide porosity to enhance the pressure buildup. As reaction spreads from the zone of thermal run-away, an explosive binder that resists breakup will limit the violence.

  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. Optimal Decision Stimuli for Risky Choice Experiments: An Adaptive Approach.

    PubMed

    Cavagnaro, Daniel R; Gonzalez, Richard; Myung, Jay I; Pitt, Mark A

    2013-02-01

    Collecting data to discriminate between models of risky choice requires careful selection of decision stimuli. Models of decision making aim to predict decisions across a wide range of possible stimuli, but practical limitations force experimenters to select only a handful of them for actual testing. Some stimuli are more diagnostic between models than others, so the choice of stimuli is critical. This paper provides the theoretical background and a methodological framework for adaptive selection of optimal stimuli for discriminating among models of risky choice. The approach, called Adaptive Design Optimization (ADO), adapts the stimulus in each experimental trial based on the results of the preceding trials. We demonstrate the validity of the approach with simulation studies aiming to discriminate Expected Utility, Weighted Expected Utility, Original Prospect Theory, and Cumulative Prospect Theory models. PMID:24532856

  6. Optimal Decision Stimuli for Risky Choice Experiments: An Adaptive Approach

    PubMed Central

    Cavagnaro, Daniel R.; Gonzalez, Richard; Myung, Jay I.; Pitt, Mark A.

    2014-01-01

    Collecting data to discriminate between models of risky choice requires careful selection of decision stimuli. Models of decision making aim to predict decisions across a wide range of possible stimuli, but practical limitations force experimenters to select only a handful of them for actual testing. Some stimuli are more diagnostic between models than others, so the choice of stimuli is critical. This paper provides the theoretical background and a methodological framework for adaptive selection of optimal stimuli for discriminating among models of risky choice. The approach, called Adaptive Design Optimization (ADO), adapts the stimulus in each experimental trial based on the results of the preceding trials. We demonstrate the validity of the approach with simulation studies aiming to discriminate Expected Utility, Weighted Expected Utility, Original Prospect Theory, and Cumulative Prospect Theory models. PMID:24532856

  7. Emotional attention for erotic stimuli: Cognitive and brain mechanisms.

    PubMed

    Sennwald, Vanessa; Pool, Eva; Brosch, Tobias; Delplanque, Sylvain; Bianchi-Demicheli, Francesco; Sander, David

    2016-06-01

    It has long been posited that among emotional stimuli, only negative threatening information modulates early shifts of attention. However, in the last few decades there has been an increase in research showing that attention is also involuntarily oriented toward positive rewarding stimuli such as babies, food, and erotic information. Because reproduction-related stimuli have some of the largest effects among positive stimuli on emotional attention, the present work reviews recent literature and proposes that the cognitive and cerebral mechanisms underlying the involuntarily attentional orientation toward threat-related information are also sensitive to erotic information. More specifically, the recent research suggests that both types of information involuntarily orient attention due to their concern relevance and that the amygdala plays an important role in detecting concern-relevant stimuli, thereby enhancing perceptual processing and influencing emotional attentional processes. PMID:26179894

  8. The effect of hearing impairment on localization dominance for single-word stimuli.

    PubMed

    Akeroyd, Michael A; Guy, Fiona H

    2011-07-01

    Localization dominance (one of the phenomena of the "precedence effect") was measured in a large number of normal-hearing and hearing-impaired individuals and related to self-reported difficulties in everyday listening. The stimuli (single words) were made-up of a "lead" followed 4 ms later by a equal-level "lag" from a different direction. The stimuli were presented from a circular ring of loudspeakers, either in quiet or in a background of spatially diffuse babble. Listeners were required to identify the loudspeaker from which they heard the sound. Localization dominance was quantified by the weighting factor c [B.G. Shinn-Cunningham et al., J. Acoust. Soc. Am. 93, 2923-2932 (1993)]. The results demonstrated large individual differences: Some listeners showed near-perfect localization dominance (c near 1) but many showed a much reduced effect. Two-thirds (64/93) of the listeners gave a value of c of at least 0.75. There was a significant correlation with hearing loss, such that better hearing listeners showed better localization dominance. One of the items of the self-report questionnaire ("Do you have the impression of sounds being exactly where you would expect them to be?") showed a significant correlation with the experimental results. This suggests that reductions in localization dominance may affect everyday auditory perception. PMID:21786901

  9. Surface Acoustic Wave Microfluidics

    NASA Astrophysics Data System (ADS)

    Yeo, Leslie Y.; Friend, James R.

    2014-01-01

    Fluid manipulations at the microscale and beyond are powerfully enabled through the use of 10-1,000-MHz acoustic waves. A superior alternative in many cases to other microfluidic actuation techniques, such high-frequency acoustics is almost universally produced by surface acoustic wave devices that employ electromechanical transduction in wafer-scale or thin-film piezoelectric media to generate the kinetic energy needed to transport and manipulate fluids placed in adjacent microfluidic structures. These waves are responsible for a diverse range of complex fluid transport phenomena - from interfacial fluid vibration and drop and confined fluid transport to jetting and atomization - underlying a flourishing research literature spanning fundamental fluid physics to chip-scale engineering applications. We highlight some of this literature to provide the reader with a historical basis, routes for more detailed study, and an impression of the field's future directions.

  10. Acoustic particle separation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Stoneburner, J. D.; Jacobi, N.; Wang, T. (Inventor)

    1985-01-01

    A method is described which uses acoustic energy to separate particles of different sizes, densities, or the like. The method includes applying acoustic energy resonant to a chamber containing a liquid of gaseous medium to set up a standing wave pattern that includes a force potential well wherein particles within the well are urged towards the center, or position of minimum force potential. A group of particles to be separated is placed in the chamber, while a non-acoustic force such as gravity is applied, so that the particles separate with the larger or denser particles moving away from the center of the well to a position near its edge and progressively smaller lighter particles moving progressively closer to the center of the well. Particles are removed from different positions within the well, so that particles are separated according to the positions they occupy in the well.

  11. Acoustic Levitation Containerless Processing

    NASA Technical Reports Server (NTRS)

    Whymark, R. R.; Rey, C. A.

    1985-01-01

    This research program consists of the development of acoustic containerless processing systems with applications in the areas of research in material sciences, as well as the production of new materials, solid forms with novel and unusual microstructures, fusion target spheres, and improved optical fibers. Efforts have been focused on the containerless processing at high temperatures for producing new kinds of glasses. Also, some development has occurred in the areas of containerlessly supporting liquids at room temperature, with applications in studies of fluid dynamics, potential undercooling of liquids, etc. The high temperature area holds the greatest promise for producing new kinds of glasses and ceramics, new alloys, and possibly unusual structural shapes, such as very uniform hollow glass shells for fusion target applications. High temperature acoustic levitation required for containerless processing has been demonstrated in low-g environments as well as in ground-based experiments. Future activities include continued development of the signals axis acoustic levitator.

  12. Acoustic energy shaping

    NASA Technical Reports Server (NTRS)

    Wang, T. G.; Elleman, D. D. (Inventor)

    1977-01-01

    A suspended mass is shaped by melting all or a selected portion of the mass and applying acoustic energy in varying amounts to different portions of the mass. In one technique for forming an optical waveguide slug, a mass of oval section is suspended and only a portion along the middle of the cross-section is heated to a largely fluid consistency. Acoustic energy is applied to opposite edges of the oval mass to press the unheated opposite edge portions together so as to form bulges at the middle of the mass. In another technique for forming a ribbon of silicon for constructing solar cells, a cylindrical thread of silicon is drawn from a molten mass of silicon, and acoustic energy is applied to opposite sides of the molten thread to flatten it into a ribbon.

  13. 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.

  14. Latticed pentamode acoustic cloak.

    PubMed

    Chen, Yi; Liu, Xiaoning; Hu, Gengkai

    2015-01-01

    We report in this work a practical design of pentamode acoustic cloak with microstructure. The proposed cloak is assembled by pentamode lattice made of a single-phase solid material. The function of rerouting acoustic wave round an obstacle has been demonstrated numerically. It is also revealed that shear related resonance due to weak shear resistance in practical pentamode lattices punctures broadband feature predicted based on ideal pentamode cloak. As a consequence, the latticed pentamode cloak can only conceal the obstacle in segmented frequency ranges. We have also shown that the shear resonance can be largely reduced by introducing material damping, and an improved broadband performance can be achieved. These works pave the way for experimental demonstration of pentamode acoustic cloak. PMID:26503821

  15. Latticed pentamode acoustic cloak

    PubMed Central

    Chen, Yi; Liu, Xiaoning; Hu, Gengkai

    2015-01-01

    We report in this work a practical design of pentamode acoustic cloak with microstructure. The proposed cloak is assembled by pentamode lattice made of a single-phase solid material. The function of rerouting acoustic wave round an obstacle has been demonstrated numerically. It is also revealed that shear related resonance due to weak shear resistance in practical pentamode lattices punctures broadband feature predicted based on ideal pentamode cloak. As a consequence, the latticed pentamode cloak can only conceal the obstacle in segmented frequency ranges. We have also shown that the shear resonance can be largely reduced by introducing material damping, and an improved broadband performance can be achieved. These works pave the way for experimental demonstration of pentamode acoustic cloak. PMID:26503821

  16. 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)

  17. Brainstem encoding of speech and musical stimuli in congenital amusia: evidence from Cantonese speakers

    PubMed Central

    Liu, Fang; Maggu, Akshay R.; Lau, Joseph C. Y.; Wong, Patrick C. M.

    2015-01-01

    Congenital amusia is a neurodevelopmental disorder of musical processing that also impacts subtle aspects of speech processing. It remains debated at what stage(s) of auditory processing deficits in amusia arise. In this study, we investigated whether amusia originates from impaired subcortical encoding of speech (in quiet and noise) and musical sounds in the brainstem. Fourteen Cantonese-speaking amusics and 14 matched controls passively listened to six Cantonese lexical tones in quiet, two Cantonese tones in noise (signal-to-noise ratios at 0 and 20 dB), and two cello tones in quiet while their frequency-following responses (FFRs) to these tones were recorded. All participants also completed a behavioral lexical tone identification task. The results indicated normal brainstem encoding of pitch in speech (in quiet and noise) and musical stimuli in amusics relative to controls, as measured by FFR pitch strength, pitch error, and stimulus-to-response correlation. There was also no group difference in neural conduction time or FFR amplitudes. Both groups demonstrated better FFRs to speech (in quiet and noise) than to musical stimuli. However, a significant group difference was observed for tone identification, with amusics showing significantly lower accuracy than controls. Analysis of the tone confusion matrices suggested that amusics were more likely than controls to confuse between tones that shared similar acoustic features. Interestingly, this deficit in lexical tone identification was not coupled with brainstem abnormality for either speech or musical stimuli. Together, our results suggest that the amusic brainstem is not functioning abnormally, although higher-order linguistic pitch processing is impaired in amusia. This finding has significant implications for theories of central auditory processing, requiring further investigations into how different stages of auditory processing interact in the human brain. PMID:25646077

  18. Early influence of auditory stimuli on upper-limb movements in young human infants: an overview

    PubMed Central

    Ferronato, Priscilla A. M.; Domellöf, Erik; Rönnqvist, Louise

    2014-01-01

    Given that the auditory system is rather well developed at the end of the third trimester of pregnancy, it is likely that couplings between acoustics and motor activity can be integrated as early as at the beginning of postnatal life. The aim of the present mini-review was to summarize and discuss studies on early auditory-motor integration, focusing particularly on upper-limb movements (one of the most crucial means to interact with the environment) in association with auditory stimuli, to develop further understanding of their significance with regard to early infant development. Many studies have investigated the relationship between various infant behaviors (e.g., sucking, visual fixation, head turning) and auditory stimuli, and established that human infants can be observed displaying couplings between action and environmental sensory stimulation already from just after birth, clearly indicating a propensity for intentional behavior. Surprisingly few studies, however, have investigated the associations between upper-limb movements and different auditory stimuli in newborns and young infants, infants born at risk for developmental disorders/delays in particular. Findings from studies of early auditory-motor interaction support that the developing integration of sensory and motor systems is a fundamental part of the process guiding the development of goal-directed action in infancy, of great importance for continued motor, perceptual, and cognitive development. At-risk infants (e.g., those born preterm) may display increasing central auditory processing disorders, negatively affecting early sensory-motor integration, and resulting in long-term consequences on gesturing, language development, and social communication. Consequently, there is a need for more studies on such implications. PMID:25278927

  19. 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.

  20. 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.

  1. 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.

  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. Densitometry By Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Trinh, Eugene H.

    1989-01-01

    "Static" and "dynamic" methods developed for measuring mass density of acoustically levitated solid particle or liquid drop. "Static" method, unknown density of sample found by comparison with another sample of known density. "Dynamic" method practiced with or without gravitational field. Advantages over conventional density-measuring techniques: sample does not have to make contact with container or other solid surface, size and shape of samples do not affect measurement significantly, sound field does not have to be know in detail, and sample can be smaller than microliter. Detailed knowledge of acoustic field not necessary.

  4. 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

  5. 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 ...

  6. Variable-Position Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Stoneburner, J. D.; Jacobi, N.; Wang, T. G.

    1983-01-01

    Method of acoustic levitation supports objects at positions other than acoustic nodes. Acoustic force is varied so it balances gravitational (or other) force, thereby maintaining object at any position within equilibrium range. Levitation method applicable to containerless processing. Such objects as table-tennis balls, hollow plastic spheres, and balsa-wood spheres levitated in laboratory by new method.

  7. How Attention Modulates Encoding of Dynamic Stimuli

    PubMed Central

    Oren, Noga; Shapira-Lichter, Irit; Lerner, Yulia; Tarrasch, Ricardo; Hendler, Talma; Giladi, Nir; Ash, Elissa L.

    2016-01-01

    When encoding a real-life, continuous stimulus, the same neural circuits support processing and integration of prior as well as new incoming information. This ongoing interplay is modulated by attention, and is evident in regions such as the prefrontal cortex section of the task positive network (TPN), and in the posterior cingulate cortex (PCC), a hub of the default mode network (DMN). Yet the exact nature of such modulation is still unclear. To investigate this issue, we utilized an fMRI task that employed movies as the encoded stimuli and manipulated attentional load via an easy or hard secondary task that was performed simultaneously with encoding. Results showed increased intersubject correlation (inter-SC) levels when encoding movies in a condition of high, as compared to low attentional load. This was evident in bilateral ventrolateral and dorsomedial prefrontal cortices and the dorsal PCC (dPCC). These regions became more attuned to the combination of the movie and the secondary task as the attentional demand of the latter increased. Activation analyses revealed that at higher load the prefrontal TPN regions were more activated, whereas the dPCC was more deactivated. Attentional load also influenced connectivity within and between the networks. At high load the dPCC was anti-correlated to the prefrontal regions, which were more functionally coherent amongst themselves. Finally and critically, greater inter-SC in the dPCC at high load during encoding predicted lower memory strength when that information was retrieved. This association between inter-SC levels and memory strength suggest that as attentional demands increased, the dPCC was more attuned to the secondary task at the expense of the encoded stimulus, thus weakening memory for the encoded stimulus. Together, our findings show that attentional load modulated the function of core TPN and DMN regions. Furthermore, the observed relationship between memory strength and the modulation of the dPCC points

  8. Stimuli-Responsive Mechanically Adaptive Polymer Nanocomposites

    PubMed Central

    Shanmuganathan, Kadhiravan; Capadona, Jeffrey R.; Rowan, Stuart J.; Weder, Christoph

    2010-01-01

    A new series of biomimetic stimuli-responsive nanocomposites, which change their mechanical properties upon exposure to physiological conditions, was prepared and investigated. The materials were produced by introducing percolating networks of cellulose nanofibers or “whiskers” derived from tunicates into poly(vinyl acetate) (PVAc), poly(butyl methacrylate) (PBMA), and blends of these polymers, with the objective of determining how the hydrophobicity and glass-transition temperature (Tg) of the polymer matrix affect the water-induced mechanically dynamic behavior. Below the Tg (~60–70 °C), the incorporation of whiskers (15.1 – 16.5% v/v) modestly increased the tensile storage moduli (E′) of the neat polymers from 0.6 to 3.8 GPa (PBMA) and from 2 to 5.2 GPa (PVAc). The reinforcement was much more dramatic above Tg, where E′ increased from 1.2 to 690 MPa (PVAc) and ~1 to 1.1 GPa (PBMA). Upon exposure to physiological conditions (immersion in artificial cerebrospinal fluid, ACSF, at 37 °C) all materials displayed a decrease of E′. The most significant contrast was seen in PVAc; for example the E′ of a 16.5% v/v PVAc/whisker nanocomposite decreased from 5.2 GPa to 12.7 MPa. Only a modest modulus decrease was measured for PBMA/whisker nanocomposite; here the E′ of a 15.1% v/v PBMA/whisker nanocomposite decreased from 3.8 to 1.2 GPa. A systematic investigation revealed that the magnitude of the mechanical contrast was related to the degree of swelling with ACSF, which was shown to increase with whisker content, temperature, and polarity of the matrix (PVAc > PBMA). The mechanical morphing of the new materials can be described in the framework of both the percolation and Halpin-Kardos models for nanocomposite reinforcement, and is the result of changing interactions among the nanoparticles and plasticization of the matrix upon swelling. PMID:20305827

  9. Dynamic bioactive stimuli-responsive polymeric surfaces

    NASA Astrophysics Data System (ADS)

    Pearson, Heather Marie

    This dissertation focuses on the design, synthesis, and development of antimicrobial and anticoagulant surfaces of polyethylene (PE), polypropylene (PP), and poly(tetrafluoroethylene) (PTFE) polymers. Aliphatic polymeric surfaces of PE and PP polymers functionalized using click chemistry reactions by the attachment of --COOH groups via microwave plasma reactions followed by functionalization with alkyne moieties. Azide containing ampicillin (AMP) was synthesized and subsequently clicked into the alkyne prepared PE and PP surfaces. Compared to non-functionalized PP and PE surfaces, the AMP clicked surfaces exhibited substantially enhanced antimicrobial activity against Staphylococcus aureus bacteria. To expand the biocompatibility of polymeric surface anticoagulant attributes, PE and PTFE surfaces were functionalized with pH-responsive poly(2-vinyl pyridine) (P2VP) and poly(acrylic acid) (PAA) polyelectrolyte tethers terminated with NH2 and COOH groups. The goal of these studies was to develop switchable stimuli-responsive polymeric surfaces that interact with biological environments and display simultaneous antimicrobial and anticoagulant properties. Antimicrobial AMP was covalently attached to --COOH terminal ends of protected PAA, while anticoagulant heparin (HEP) was attached to terminal --NH2 groups of P2VP. When pH < 2.3, the P2VP segments are protonated and extend, but for pH > 5.5, they collapse while the PAA segments extend. Such surfaces, when exposed to Staphylococcus aureus, inhibit bacterial growth due to the presence of AMP, as well as are effective anticoagulants due to the presence of covalently attached HEP. Comparison of these "dynamic" pH responsive surfaces with "static" surfaces terminated with AMP entities show significant enhancement of longevity and surface activity against microbial film formation. The last portion of this dissertation focuses on the covalent attachment of living T1 and Φ11 bacteriophages (phages) on PE and PTFE surface

  10. 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.

  11. 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.

  12. Numerosity judgments for tactile stimuli distributed over the body surface.

    PubMed

    Gallace, Alberto; Tan, Hong Z; Spence, Charles

    2006-01-01

    A large body of research now supports the claim that two different and dissociable processes are involved in making numerosity judgments regarding visual stimuli: subitising (fast and nearly errorless) for up to 4 stimuli, and counting (slow and error-prone) when more than 4 stimuli are presented. We studied tactile numerosity judgments for combinations of 1-7 vibrotactile stimuli presented simultaneously over the body surface. In experiment 1, the stimuli were presented once, while in experiment 2 conditions of single presentation and repeated presentation of the stimulus were compared. Neither experiment provided any evidence for a discontinuity in the slope of either the RT or error data suggesting that subitisation does not occur for tactile stimuli. By systematically varying the intensity of the vibrotactile stimuli in experiment 3, we were able to demonstrate that participants were not simply using the 'global intensity' of the whole tactile display to make their tactile numerosity judgments, but were, instead, using information concerning the number of tactors activated. The results of the three experiments reported here are discussed in relation to current theories of counting and subitising, and potential implications for the design of tactile user interfaces are highlighted. PMID:16583769

  13. Psychophysical definition of S-cone stimuli in the macaque

    PubMed Central

    Hall, Nathan; Colby, Carol

    2013-01-01

    We used the perceptual reports of nonhuman primates to perform psychophysical calibrations of S-cone isolating stimuli. S-cone stimuli were calibrated separately at several spatial locations for each monkey. To do this we exploited the effect of transient tritanopia, which causes a selective decrease of sensitivity in the observer's S-cone channel. At the start of each transient tritanopia trial monkeys were visually adapted to a bright yellow background. This type of adaptation is known to induce transient tritanopia. Calibrated S-cone isolating stimuli were determined by finding a near S-cone stimulus whose detection threshold was maximally elevated during transient tritanopia. At the start of each control trial, monkeys were adapted to a bright white background. In these trials, monkeys' detection thresholds for near S-cone stimuli were unchanged. We found that S-cone isolating stimuli could be determined at most locations tested in each monkey. Calibrated S-cone stimuli were particular to both spatial location and animal. To understand the visual system as a whole in vivo requires physiological methods not possible in human subjects. The present results open the door to novel behavioral and physiological experiments by showing that S-cone isolating stimuli can be calibrated in monkeys. PMID:23412341

  14. Transitive responding in hooded crows requires linearly ordered stimuli.

    PubMed Central

    Lazareva, Olga F; Smirnova, Anna A; Bagozkaja, Maria S; Zorina, Zoya A; Rayevsky, Vladimir V; Wasserman, Edward A

    2004-01-01

    Eight crows were taught to discriminate overlapping pairs of visual stimuli (A+ B-, B+ C-, C+ D-, and D+ E-). For 4 birds, the stimuli were colored cards with a circle of the same color on the reverse side whose diameter decreased from A to E (ordered feedback group). These circles were made available for comparison to potentially help the crows order the stimuli along a physical dimension. For the other 4 birds, the circles corresponding to the colored cards had the same diameter (constant feedback group). In later testing, a novel choice pair (BD) was presented. Reinforcement history involving stimuli B and D was controlled so that the reinforcement/nonreinforcement ratios for the latter would be greater than for the former. If, during the BD test, the crows chose between stimuli according to these reinforcement/nonreinforcement ratios, then they should prefer D; if they chose according to the diameter of the feedback stimuli, then they should prefer B. In the ordered feedback group, the crows strongly preferred B over D; in the constant feedback group, the crows' choice did not differ significantly from chance. These results, plus simulations using associative models, suggest that the orderability of the postchoice feedback stimuli is important for crows' transitive responding. PMID:15484868

  15. Phonetically Trained and Untrained Adults' Transcription of Place of Articulation for Intervocalic Lingual Stops with Intermediate Acoustic Cues

    ERIC Educational Resources Information Center

    Mayo, Catherine; Gibbon, Fiona; Clark, Robert A. J.

    2013-01-01

    Purpose: In this study, the authors aimed to investigate how listener training and the presence of intermediate acoustic cues influence transcription variability for conflicting cue speech stimuli. Method: Twenty listeners with training in transcribing disordered speech, and 26 untrained listeners, were asked to make forced-choice labeling…

  16. Neural Processing of Emotional Musical and Nonmusical Stimuli in Depression

    PubMed Central

    Atchley, Ruth Ann; Chrysikou, Evangelia; Martin, Laura E.; Clair, Alicia A.; Ingram, Rick E.; Simmons, W. Kyle; Savage, Cary R.

    2016-01-01

    Background Anterior cingulate cortex (ACC) and striatum are part of the emotional neural circuitry implicated in major depressive disorder (MDD). Music is often used for emotion regulation, and pleasurable music listening activates the dopaminergic system in the brain, including the ACC. The present study uses functional MRI (fMRI) and an emotional nonmusical and musical stimuli paradigm to examine how neural processing of emotionally provocative auditory stimuli is altered within the ACC and striatum in depression. Method Nineteen MDD and 20 never-depressed (ND) control participants listened to standardized positive and negative emotional musical and nonmusical stimuli during fMRI scanning and gave subjective ratings of valence and arousal following scanning. Results ND participants exhibited greater activation to positive versus negative stimuli in ventral ACC. When compared with ND participants, MDD participants showed a different pattern of activation in ACC. In the rostral part of the ACC, ND participants showed greater activation for positive information, while MDD participants showed greater activation to negative information. In dorsal ACC, the pattern of activation distinguished between the types of stimuli, with ND participants showing greater activation to music compared to nonmusical stimuli, while MDD participants showed greater activation to nonmusical stimuli, with the greatest response to negative nonmusical stimuli. No group differences were found in striatum. Conclusions These results suggest that people with depression may process emotional auditory stimuli differently based on both the type of stimulation and the emotional content of that stimulation. This raises the possibility that music may be useful in retraining ACC function, potentially leading to more effective and targeted treatments. PMID:27284693

  17. 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…

  18. Improved acoustic levitation apparatus

    NASA Technical Reports Server (NTRS)

    Berge, L. H.; Johnson, J. L.; Oran, W. A.; Reiss, D. A.

    1980-01-01

    Concave driver and reflector enhance and shape levitation forces in acoustic resonance system. Single-mode standing-wave pattern is focused by ring element situated between driver and reflector. Concave surfaces increase levitating forces up to factor of 6 as opposed to conventional flat surfaces, making it possible to suspend heavier objects.

  19. 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.

  20. Acoustic leak detection system

    SciTech Connect

    Peacock, M.J.

    1993-08-03

    An acoustic leak detection system is described for determining the location of leaks in storage tanks, comprising: (a) sensor means for detecting a leak signal; (b) data acquisition means for digitizing and storing leak signals meeting preset criterion; and (c) analysis means for analyzing the digitized signals and computing the location of the source of the leak signals.