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International Journal of... Dec 2023Examining appetitive and aversive responses toward body image stimuli of those with disordered eating may illuminate motivational systems unique to eating pathology. The...
Facial EMG startle response and self-report reactions after exposure to severely underweight and severely obese body images in individuals with disordered eating: An examination of motivational responses.
Examining appetitive and aversive responses toward body image stimuli of those with disordered eating may illuminate motivational systems unique to eating pathology. The current study extended previous literature by examining self-report and startle responses to a range of body sizes. In this cross-sectional design, female, adult participants (n = 45) were sorted into disordered eating (DE; n = 22) and healthy control (HC; n = 23) groups based on Eating Disorder Examination Questionnaire global scores that were one standard deviation above or below normative values. Participants viewed eight computer-generated female body pictures from each group: severely underweight (BMI < 16.0), average (BMI 18.5-24.99), and severely obese (BMI > 40.0). Startle responses and self-reported valence and anxiety scores were collected to assess implicit and explicit reactions. 2 × 3 ANCOVA/ANOVAs were used to examine startle responses and self-report differences between groups, in response to image types. Results indicated startle responses did not differ between groups. There was a significant main effect for body picture type (p < .001), after controlling for psychotropic medication. Startle responses were higher for severely underweight body images compared to severely obese body images, although non-significant at post-hoc. The DE group reported higher levels of anxiety and sadness when viewing body images compared to the HC group. Average bodies were rated as less anxiety provoking and more positive than severely underweight and obese bodies. Group differences in anxiety and valence scores could be due to more maladaptive cognitions related to fear of weight gain among people with disordered eating.
Topics: Adult; Humans; Female; Body Image; Self Report; Reflex, Startle; Cross-Sectional Studies; Thinness; Feeding and Eating Disorders; Obesity
PubMed: 37802389
DOI: 10.1016/j.ijpsycho.2023.112249 -
Acta Physiologica (Oxford, England) May 2016Loud acoustic stimuli can unintentionally elicit volitional acts when a person is in a state of readiness to execute them (the StartReact effect). It has been assumed... (Review)
Review
Loud acoustic stimuli can unintentionally elicit volitional acts when a person is in a state of readiness to execute them (the StartReact effect). It has been assumed that the same subcortical pathways and brain regions underlie all instances of the StartReact effect. They are proposed to involve the startle reflex pathways, and the eliciting mechanism is distinct from other ways in which sound can affect the motor system. We present an integrative review which shows that there is no evidence to support these assumptions. We argue that motor command generation for learned, volitional orofacial, laryngeal and distal limb movements is cortical and the StartReact effect for such movements involves transcortical pathways. In contrast, command generation for saccades, locomotor corrections and postural adjustments is subcortical and subcortical pathways are implicated in the StartReact effect for these cases. We conclude that the StartReact effect is not a special phenomenon mediated by startle reflex pathways, but rather is a particular manifestation of the excitatory effects of intense stimulation on the central nervous system.
Topics: Acoustic Stimulation; Animals; Central Nervous System; Humans; Movement; Reflex, Startle
PubMed: 26548462
DOI: 10.1111/apha.12627 -
Scientific Reports Nov 2021The startle reflex in larval zebrafish describes a C-bend of the body occurring in response to sudden, unexpected, stimuli of different sensory modalities. Alterations...
The startle reflex in larval zebrafish describes a C-bend of the body occurring in response to sudden, unexpected, stimuli of different sensory modalities. Alterations in the startle reflex habituation (SRH) have been reported in various human and animal models of neurological and psychiatric conditions and are hence considered an important behavioural marker of neurophysiological function. The amplitude, offset and decay constant of the auditory SRH in larval zebrafish have recently been characterised, revealing that the measures are affected by variation in vibratory frequency, intensity, and interstimulus-interval. Currently, no study provides a model-based analysis of the effect of physical properties of light stimuli on the visual SRH. This study assessed the effect of incremental light-stimulus intensity on the SRH of larval zebrafish through a repeated-measures design. Their total locomotor responses were normalised for the time factor, based on the behaviour of a (non-stimulated) control group. A linear regression indicated that light intensity positively predicts locomotor responses due to larger SRH decay constants and offsets. The conclusions of this study provide important insights as to the effect of light properties on the SRH in larval zebrafish. Our methodology and findings constitute a relevant reference framework for further investigation in translational neurophysiological research.
Topics: Animals; Behavior, Animal; Habituation, Psychophysiologic; Larva; Light; Locomotion; Models, Animal; Reflex, Startle; Zebrafish
PubMed: 34789729
DOI: 10.1038/s41598-021-00535-9 -
Biological Psychology Feb 2017Anger and aggression are frequent problems in deployed military personnel. A lowered threshold of perceiving and responding to threat can trigger impulsive aggression....
Anger and aggression are frequent problems in deployed military personnel. A lowered threshold of perceiving and responding to threat can trigger impulsive aggression. This can be indicated by an exaggerated startle response. Fifty-two veterans with anger and aggression problems (Anger group) and 50 control veterans were tested using a startle experiment with 10 startle probes and 10 prepulse trials, presented in a random order and with a random interval between the trials. Predictors (demographics, Trait Anger, State Anger, Harm Avoidance and Anxious Arousal) for the startle response within the Anger group were tested. Increased EMG responses were found to the startle probes in the Anger Group compared to the Control group, but not to the prepulse trials. Furthermore, Harm Avoidance and State Anger predicted the increased startle reflex within the Anger group, whereas Trait Anger was negatively related to the startle reflex. These findings indicate that threat reactivity is increased in anger and aggression problems. These problems are not only caused by an anxious predisposition, the degree of anger also predicts the startle reflex.
Topics: Acoustic Stimulation; Adult; Aggression; Anger; Anxiety; Humans; Male; Reflex, Startle; Veterans
PubMed: 27939701
DOI: 10.1016/j.biopsycho.2016.12.004 -
Frontiers of Medicine Jun 2017Zebrafish is an emerging animal model for studies on auditory system. This model presents high comparability with humans, good accessibility to the hearing organ, and... (Review)
Review
Zebrafish is an emerging animal model for studies on auditory system. This model presents high comparability with humans, good accessibility to the hearing organ, and high throughput capacity. To better utilize this animal model, methodologies need to be used to quantify the hearing function of the zebrafish. Zebrafish displays a series of innate and robust behavior related to its auditory function. Here, we reviewed the advantage of using zebrafish in auditory research and then introduced three behavioral tests, as follows: the startle response, the vestibular-ocular reflex, and rheotaxis. These tests are discussed in terms of their physiological characteristics, up-to-date technical development, and apparatus description. Test limitation and areas to improve are also introduced. Finally, we revealed the feasibility of these applications in zebrafish behavioral assessment and their potential in the high-throughput screening on hearing-related genes and drugs.
Topics: Animals; Behavior Rating Scale; Behavior, Animal; Hair Cells, Auditory; High-Throughput Screening Assays; Humans; Models, Animal; Reflex, Startle; Zebrafish
PubMed: 28349300
DOI: 10.1007/s11684-017-0507-x -
Human Brain Mapping Nov 2021Startle reflex is modulated when a weaker sensory stimulus ("prepulse") precedes a startling stimulus ("pulse"). Prepulse Inhibition (PPI) is the attenuation of the...
Startle reflex is modulated when a weaker sensory stimulus ("prepulse") precedes a startling stimulus ("pulse"). Prepulse Inhibition (PPI) is the attenuation of the startle reflex (prepulse precedes pulse by 30-500 ms), whereas Prepulse Facilitation (PPF) is the enhancement of the startle reflex (prepulse precedes pulse by 500-6000 ms). Here, we critically appraise human studies using functional neuroimaging to establish brain regions associated with PPI and PPF. Of 10 studies, nine studies revealed thalamic, striatal and frontal lobe activation during PPI in healthy groups, and activation deficits in the cortico-striato-pallido-thalamic circuitry in schizophrenia (three studies) and Tourette Syndrome (two studies). One study revealed a shared network for PPI and PPF in frontal regions and cerebellum, with PPF networks recruiting superior medial gyrus and cingulate cortex. The main gaps in the literature are (i) limited PPF research and whether PPI and PPF operate on separate/shared networks, (ii) no data on sex differences in neural underpinnings of PPI and PPF, and (iii) no data on neural underpinnings of PPI and PPF in other clinical disorders.
Topics: Functional Neuroimaging; Humans; Perception; Prepulse Inhibition; Reflex, Startle; Schizophrenia; Sensation; Tourette Syndrome
PubMed: 34414633
DOI: 10.1002/hbm.25631 -
Behavioural Brain Research Aug 2023Zika virus (ZIKV) infection causes severe neurological consequences in both gestationally-exposed infants and adults. Sensorial gating deficits strongly correlate to the...
Zika virus (ZIKV) infection causes severe neurological consequences in both gestationally-exposed infants and adults. Sensorial gating deficits strongly correlate to the motor, sensorial and cognitive impairments observed in ZIKV-infected patients. However, no startle response or prepulse inhibition (PPI) assessment has been made in patients or animal models. In this study, we identified different outcomes according to the age of infection and sex in mice: neonatally infected animals presented an increase in PPI and delayed startle latency. However, adult-infected male mice presented lower startle amplitude, while a PPI impairment was observed 14 days after infection in both sexes. Our data further the understanding of the functional impacts of ZIKV on the developing and mature nervous system, which could help explain other behavioral and cognitive alterations caused by the virus. With this study, we support the startle reflex testing in ZIKV-exposed patients, especially infants, allowing for early detection of functional neuromotor damage and early intervention.
Topics: Female; Male; Animals; Mice; Reflex, Startle; Prepulse Inhibition; Zika Virus; Zika Virus Infection; Acoustic Stimulation
PubMed: 37263423
DOI: 10.1016/j.bbr.2023.114519 -
Journal of Behavior Therapy and... Mar 2019Following an aversive experience, fears often generalize across contexts. Contextual fear generalization is modeled in a laboratory paradigm in which one context (CTX+)...
BACKGROUND AND OBJECTIVES
Following an aversive experience, fears often generalize across contexts. Contextual fear generalization is modeled in a laboratory paradigm in which one context (CTX+) is paired with an aversive unconditional stimulus (US), while the other context (CTX-) is not. The current study sought to validate a novel paradigm assessing contextual fear generalization, and to determine the extent to which stress and anxiety symptoms enhanced contextual fear generalization.
METHODS
Fifty-nine participants were randomized to a stress induction or control arithmetic test, followed by a differential context fear conditioning paradigm. One to three days later, participants completed a generalization gradient test with CTX+, CTX, and four generalization contexts.
RESULTS
We found successful contextual fear conditioning on measures of US expectancy, self-report fear and valence, and startle reflex, and linear generalization across the contextual gradient on expectancies and self-report measures. Acute stress induction impaired learning of the US-CTX + association during context fear acquisition. Anxiety significantly predicted greater contextual fear generalization as measured by US expectancy.
LIMITATIONS
Our study provides pilot data introducing a novel fear conditioning paradigm to assess contextual generalization of fear. There is a need for further replication to validate its utility.
CONCLUSIONS
Findings suggest that individuals high in anxiety show greater contextual fear generalization as measured by US expectancy. Results are discussed in terms of potential mechanisms that contribute to pervasive anxiety.
Topics: Adult; Anxiety; Conditioning, Classical; Fear; Female; Generalization, Psychological; Humans; Male; Pilot Projects; Reflex, Startle; Stress, Psychological; Young Adult
PubMed: 30193203
DOI: 10.1016/j.jbtep.2018.08.009 -
Neuropharmacology Jan 2020Behavioral arrest is an essential feature of an animal's survival. Acoustic startle reflex (ASR) is an involuntary whole-body contraction of the skeletal musculature to...
Behavioral arrest is an essential feature of an animal's survival. Acoustic startle reflex (ASR) is an involuntary whole-body contraction of the skeletal musculature to an unexpected auditory stimulus. This strong reaction can be decreased by prepulse inhibition (PPI) phenomenon; which, for example, is important in reducing distraction during the processing of sensory input. Several brainstem regions are involved in the PPI and startle reflex, but a previous study from our laboratory showed that the main input structure of Basal Ganglia (BG) - the striatum - modulates PPI. The pallidum and nigra are connected with striatum and these brainstem structures. Here, we investigated the role of these striatum outputs in the brain regions on startle amplitude, PPI regulation, and exploratory behavior in Wistar rats. The temporary bilateral inhibition of the globus pallidus (GP) by muscimol lead to motor impairment, without disturbing startle amplitude or PPI. Similarly, inhibition of the entopeduncular nucleus (EPN) specifically disrupted the exploratory behavior. On the other hand, the substantia nigra reticulata (SNr) inhibition interfered in all measured behaviors: decreased the PPI percentage, increased ASR and impaired the locomotor activity. The nigra is a key BG output structure which projects to the thalamus and brainstem. These findings extend our previous study showing that the striatum neurons expressing D1 receptors involvement in PPI occurs via the direct pathway to SNr, but not to the pallidum which more likely occurs by its connection with the caudal pontine nucleus, superior colliculus and/or pedunculopontine nucleus pivotal structures for startle reflex modulation.
Topics: Animals; GABA-A Receptor Agonists; Globus Pallidus; Locomotion; Microinjections; Muscimol; Pars Reticulata; Prepulse Inhibition; Rats; Rats, Wistar; Reflex, Startle
PubMed: 31563465
DOI: 10.1016/j.neuropharm.2019.107796 -
Neuroscience Letters Aug 2021We aimed to investigate the brainstem circuits to reveal if there was any abnormality in these circuits in clinically diagnosed patients with NREM parasomnias during... (Observational Study)
Observational Study
OBJECTIVE
We aimed to investigate the brainstem circuits to reveal if there was any abnormality in these circuits in clinically diagnosed patients with NREM parasomnias during wakefulness.
METHODS
Twelve patients with NREM-sleep parasomnia diagnosed according to ICSD-3 criteria and a control group of 16 healthy subjects were enrolled into our study. We analyzed the auditory startle reflex (ASR), blink reflex (BR), prepulse inhibition (PPI) of BR and recovery excitability of BR.
RESULTS
There was a trend for longer responses from orbicularis oculi and sternocleidomastoid muscles after auditory stimulation in the patients compared to those in the healthy subjects. The recovery percentages at 200 ms and 300 ms showed a borderline significance in the patients. No significant difference was found in the R2-PPI between the patients and healthy subjects.
CONCLUSIONS
Our results suggest a mildly enhanced ASR and relatively early facilitation of BR excitability in patients with NREM-sleep parasomnia during daytime. Although our findings suggest involvement of brainstem networks in NREM-sleep parasomnia during wakefulness, it would be better to study these networks at night and during daytime to see if there is any contribution.
Topics: Adult; Blinking; Brain Stem; Case-Control Studies; Electroencephalography; Female; Healthy Volunteers; Humans; Male; Nerve Net; Parasomnias; Polysomnography; Prepulse Inhibition; Reflex, Startle; Sleep Stages; Wakefulness; Young Adult
PubMed: 34153369
DOI: 10.1016/j.neulet.2021.136075