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Psychophysiology Dec 2022Trace fear conditioning is an important research paradigm to model aversive learning in biological or clinical scenarios, where predictors (conditioned stimuli, CS) and...
Trace fear conditioning is an important research paradigm to model aversive learning in biological or clinical scenarios, where predictors (conditioned stimuli, CS) and aversive outcomes (unconditioned stimuli, US) are separated in time. The optimal measurement of human trace fear conditioning, and in particular of memory retention after consolidation, is currently unclear. We conducted two identical experiments (N = 28, N = 28) with a 15-s trace interval and a recall test 1 week after acquisition, while recording several psychophysiological observables. In a calibration approach, we explored which learning and memory measures distinguished CS+ and CS- in the first experiment and confirmed the most sensitive measures in the second experiment. We found that in the recall test without reinforcement, only fear-potentiated startle but not skin conductance, pupil size, heart period, or respiration amplitude, differentiated CS+ and CS-. During acquisition without startle probes, skin conductance responses and pupil size responses but not heart period or respiration amplitude differentiated CS+ and CS-. As a side finding, there was no evidence for extinction of fear-potentiated startle over 30 trials without reinforcement. These results may be useful to inform future substantive research using human trace fear conditioning protocols.
Topics: Humans; Fear; Conditioning, Classical; Memory; Conditioning, Operant; Learning; Reflex, Startle; Extinction, Psychological
PubMed: 35675529
DOI: 10.1111/psyp.14119 -
Parkinsonism & Related Disorders Feb 2022Latah is a culture-specific syndrome characterized by exaggerated startle response, echolalia, palilalia, echopraxia, coprolalia, forced obedience and involuntary... (Review)
Review
Latah is a culture-specific syndrome characterized by exaggerated startle response, echolalia, palilalia, echopraxia, coprolalia, forced obedience and involuntary vocalization in response to startle. Latah is stimulus-induced and is associated with behavior and psychiatric features. The aim of this review is to provide a comprehensive description on latah from a regional perspective based on previous literature and clinical experiences and highlight the clinical characteristics of latah from a movement disorders perspective. The pathophysiology of latah is complex and poorly understood although psychological stressors have been implicated. In view of the distressing psychosocial impact of latah, this neuropsychiatric startle syndrome warrants further studies to understand the pathophysiology and identify the appropriate treatments.
Topics: Humans; Movement Disorders; Reflex, Startle; Somatoform Disorders; Stiff-Person Syndrome
PubMed: 35120841
DOI: 10.1016/j.parkreldis.2022.01.013 -
Acta Psychologica Oct 2021The startle reflex has been suggested to operate as a psychophysiological marker of psychopathic personality, based on findings from studies using a range of different... (Review)
Review
The startle reflex has been suggested to operate as a psychophysiological marker of psychopathic personality, based on findings from studies using a range of different methodologies and participant samples. The present review aims at synthesizing existing evidence of the relationship between psychopathy and the startle reflex across task paradigms, psychopathic personality subtypes and subdimensions, participant samples (i.e., incarcerated/ clinical or non-offenders), and age groups using the triarchic model of psychopathy as a frame of reference. Systematic literature searches were conducted up until the 24th of March 2020 in PubMed, PsycINFO, and Web of Science. A total of 2311 potential studies were identified, out of which 40 met relevancy and quality criteria. Results indicate that reduced aversive startle potentiation is associated with psychopathic personality in general, but clusters of traits relating to the triarchic model constructs of boldness and meanness in particular. Available evidence suggest that startle paradigms could be meaningful for differentiating individuals with and without psychopathic personality. Findings support suggestions of psychopathic personality as a multifaceted, rather than a unitary construct. Reduced aversive startle potentiation has also been found in relation to psychopathic features in child-aged samples but work of this kind is limited and more research is needed. Future studies should focus on greater consistency in task paradigms and analytic strategies to enhance the capacity to compare and integrate findings across studies.
Topics: Adolescent; Affect; Aged; Antisocial Personality Disorder; Child; Humans; Reflex, Startle; Young Adult
PubMed: 34628215
DOI: 10.1016/j.actpsy.2021.103427 -
The Journal of Experimental Biology Mar 2020The acoustic startle reflex is an oligo-synaptic reflex arc elicited by rapid-onset sounds. Odontocetes evolved a range of specific auditory adaptations to aquatic...
The acoustic startle reflex is an oligo-synaptic reflex arc elicited by rapid-onset sounds. Odontocetes evolved a range of specific auditory adaptations to aquatic hearing and echolocation, e.g. the ability to downregulate their auditory sensitivity when emitting clicks. However, it remains unclear whether these adaptations also led to changes of the startle reflex. We investigated reactions to startling sounds in two bottlenose dolphins () and one false killer whale (). Animals were exposed to 50 ms, 1/3 octave band noise pulses of varying levels at frequencies of 1, 10, 25 and 32 kHz while positioned in a hoop station. Startle responses were quantified by measuring rapid muscle contractions using a three-dimensional accelerometer attached to the dolphin. Startle magnitude increased exponentially with increasing received levels. Startle thresholds were frequency dependent and ranged from 131 dB at 32 kHz to 153 dB at 1 kHz (re. 1 µPa). Startle thresholds only exceeded masked auditory AEP thresholds of the animals by 47 dB but were ∼82 dB above published behavioural audiograms for these species. We also tested the effect of stimulus rise time on startle magnitude using a broadband noise pulse. Startle responses decreased with increasing rise times from 2 to 100 ms. Models suggested that rise times of 141-220 ms were necessary to completely mitigate startle responses. Our data showed that the startle reflex is conserved in odontocetes and follows similar principles as in terrestrial mammals. These principles should be considered when assessing and mitigating the effects of anthropogenic noise on marine mammals.
Topics: Acoustic Stimulation; Animals; Auditory Threshold; Bottle-Nosed Dolphin; Dolphins; Echolocation; Female; Hawaii; Male; Reflex, Startle
PubMed: 32165452
DOI: 10.1242/jeb.208470 -
Experimental Brain Research Jan 2021Forward models are a component of the motor system that predicts the sensory consequences of our actions. These models play several key roles in motor control and are...
Forward models are a component of the motor system that predicts the sensory consequences of our actions. These models play several key roles in motor control and are hypothesized to underlie (among other things) the two phenomena under investigation in this experiment: The feeling of agency that we have over self-initiated actions (as opposed to reflexes), and "temporal binding", in which self-caused sensations are judged to have occurred earlier in time than they actually did. This experiment probes the connection between forward models and both of these phenomena using the "Startle" paradigm. In the Startle paradigm, a startlingly loud sound causes people to initiate a prepared action at a very short latency. It is hypothesized that the latency of a startle-initiated action is so short that normal cortical operations (including forward models) are circumvented. This experiment replicates the temporal-binding effect and simultaneously measures participants' sense of agency over their actions. The results show that both the temporal-binding effect and the sense of agency we have over our own actions is disrupted under the startle paradigm in line with the theory that these phenomena both rely on forward models. Furthermore, this experiment provides evidence in support of the claim that a startle-induced action is qualitatively different from other actions.
Topics: Emotions; Humans; Reflex, Startle
PubMed: 33165671
DOI: 10.1007/s00221-020-05972-y -
Ageing Research Reviews May 2020Inhibition plays a crucial role in many functional domains, such as cognition, emotion, and actions. Studies on cognitive aging demonstrate changes in inhibitory... (Review)
Review
Inhibition plays a crucial role in many functional domains, such as cognition, emotion, and actions. Studies on cognitive aging demonstrate changes in inhibitory mechanisms are age- and pathology-related. Prepulse inhibition (PPI) is the suppression of an acoustic startle reflex (ASR) to an intense stimulus when a weak prepulse stimulus precedes the startle stimulus. A reduction of PPI is thought to reflect dysfunction of sensorimotor gating which normally suppresses excessive behavioral responses to disruptive stimuli. Both human and rodent studies show age-dependent alterations of PPI of the ASR that are further compromised in Alzheimer's disease (AD). The auditory P50 gating, an index of repetition suppression, also is characterized as a putative electrophysiological biomarker of prodromal AD. This review provides the latest evidence of age- and AD-associated impairment of sensorimotor gating based upon both human and rodent studies, as well as the AD-related disruption of P50 gating in humans. It begins with a concise review of neural networks underlying PPI regulation. Then, evidence of age- and AD-related dysfunction of both PPI and P50 gating is discussed. The attentional/ emotional aspects of sensorimotor gating and the neurotransmitter mechanisms underpinning PPI and P50 gating are also reviewed. The review ends with conclusions and research directions.
Topics: Acoustic Stimulation; Aging; Alzheimer Disease; Humans; Neural Inhibition; Prepulse Inhibition; Reaction Time; Reflex, Startle
PubMed: 32092463
DOI: 10.1016/j.arr.2020.101028 -
Hearing Research Feb 2022The primary startle response (SR) is an innate reaction evoked by sudden and intense acoustic, tactile or visual stimuli. In rodents and humans the SR involves reflexive...
The primary startle response (SR) is an innate reaction evoked by sudden and intense acoustic, tactile or visual stimuli. In rodents and humans the SR involves reflexive contractions of the face, neck and limb muscles. The acoustic startle response (ASR) pathway consists of auditory nerve fibers (AN), cochlear root neurons (CRNs) and giant neurons of the caudal pontine reticular nucleus (PnC), which synapse on cranial and spinal motor neurons. The tactile startle response (TSR) is transmitted by primary sensory neurons to the principal sensory (Pr5) and spinal (Sp5) trigeminal nuclei. The ventral part of Pr5 projects directly to the PnC neurons. The SR requires rapid transmission of sensory information to initiate a fast motor response. Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPAR) are necessary to transmit auditory information to the PnC neurons and elicit the SR. AMPARs containing the glutamate AMPAR subunit 4 (GluA4) have fast kinetics, which makes them ideal candidates to transmit the SR signal. This study examined the role of GluA4 within the primary SR pathway by using GluA4 knockout (GluA4-KO) mice. Deletion of GluA4 considerably decreased the amplitude and probability of successful ASR and TSR, indicating that the presence of this subunit is critical at a common station within the startle pathway. We conclude that deletion of GluA4 affects the transmission of sensory signals from acoustic and tactile pathways to the motor component of the startle reflex. Therefore, GluA4 is required for the full response and for reliable elicitation of the startle response.
Topics: Acoustic Stimulation; Acoustics; Animals; Mice; Neurons; Reflex, Startle; Synapses
PubMed: 34915397
DOI: 10.1016/j.heares.2021.108410 -
Psychophysiology Oct 2022Studies suggest that deficits in startle reflex habituation occur in trait and clinical anxiety. Measures of habituation are affected by the magnitude of the initial...
Studies suggest that deficits in startle reflex habituation occur in trait and clinical anxiety. Measures of habituation are affected by the magnitude of the initial response, with larger initial responses predicting a steeper decline in response over repeated trials. This relationship between initial value and change, commonly called the Law of Initial Value or initial value dependence (IVD), has been partialled out as a covariate in habituation research, but variation in IVD may be informative in itself, reflecting differences in physiological reactivity. The present study explored how trait anxiety and contextual anxiety relate to habituation kinetics of the startle eyeblink response: initial value, linear habituation slope, and the relationship between them (IVD). Participants (n = 31; 15 Control, 16 Contextual Anxiety [CA]) were exposed to two blocks of acoustic startle stimuli, and CA participants were warned that they may receive an electrical shock to the wrist during block 2. Trait anxiety did not predict habituation slope, but it did predict a weaker IVD relationship, meaning that high initial startle magnitude was less predictive of a steep response decline in trait-anxious subjects. Meanwhile, CA did not impact startle habituation or IVD. The results suggest that individual differences in trait anxiety are related to the relationship between initial physiological response magnitude and subsequent change in response. IVD in startle habituation may thus serve as a better biomarker of healthy emotional responding than startle habituation per se.
Topics: Acoustic Stimulation; Anxiety; Blinking; Emotions; Habituation, Psychophysiologic; Humans; Reflex, Startle
PubMed: 35415921
DOI: 10.1111/psyp.14071 -
Depression and Anxiety Oct 2021Recent studies have found that attachment security primes can inhibit fear acquisition. This current study aimed to examine whether a brief imaginal prime of one's...
BACKGROUND
Recent studies have found that attachment security primes can inhibit fear acquisition. This current study aimed to examine whether a brief imaginal prime of one's attachment figure could impact on fear consolidation.
METHODS
A total of 75 participants underwent fear conditioning on Day 1 and fear recall was tested on Day 2. Immediately following conditioning, half the participants were instructed to imagine an attachment figure while the other half imagined a nonattachment positive situation. Fear-potentiated startle and subjective expectancy of shock ratings were used as the measures of fear learning across trials.
RESULTS
The attachment group showed significantly lower levels of fear recall on Day 2 at both physiological and subjective levels. Furthermore, this effect was moderated by attachment anxiety, such that it was greatest for individuals who were securely attached.
CONCLUSIONS
These findings suggest that attachment relationships are protective during the consolidation of fear memories, and may have implications for how social attachments may impact how anxiety disorders can develop.
Topics: Anxiety; Anxiety Disorders; Conditioning, Classical; Extinction, Psychological; Fear; Humans; Reflex, Startle
PubMed: 33949748
DOI: 10.1002/da.23166 -
Neuroscience and Biobehavioral Reviews Aug 2019Startle reflex potentiation versus startle attenuation to unpleasant versus pleasant stimuli likely reflect priming of the defensive versus appetitive motivational...
Startle reflex potentiation versus startle attenuation to unpleasant versus pleasant stimuli likely reflect priming of the defensive versus appetitive motivational systems, respectively. This review summarizes and systemizes the literature on affective startle modulation related to psychopathologies with the aim to reveal underlying mechanisms across psychopathologies. We found evidence for psychopathologies characterized by increased startle potentiation to unpleasant stimuli (anxiety disorders), decreased startle potentiation to unpleasant stimuli (psychopathy), decreased startle attenuation to pleasant stimuli (ADHD), as well as a general hyporeactivity to affective stimuli (depression). Increased versus decreased startle responses to disorder-specific stimuli characterize specific phobia and drug dependence. No psychopathology is characterized by increased startle attenuation to standard pleasant stimuli or a general hyperreactivity to affective stimuli. This review indicates that the defensive and the appetitive systems operate independently mostly in accordance with the motivational priming hypothesis and that affective startle modulation is a highly valuable paradigm to unraveling dysfunctions of the defensive and appetitive systems in psychopathologies as requested by the Research Domain Criteria initiative.
Topics: Affect; Antisocial Personality Disorder; Anxiety Disorders; Appetitive Behavior; Attention Deficit Disorder with Hyperactivity; Avoidance Learning; Depressive Disorder; Humans; Motivation; Reflex, Abnormal; Reflex, Startle
PubMed: 31129237
DOI: 10.1016/j.neubiorev.2019.05.019