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Attention and affect in dysphoria: Insights from startle reflex modulation and cardiac deceleration.Behaviour Research and Therapy Aug 2020The present study investigated the interplay between attention and affective disposition during emotional processing in dysphoria. Attentional and affective startle...
The present study investigated the interplay between attention and affective disposition during emotional processing in dysphoria. Attentional and affective startle modulation and cardiac deceleration were assessed during the viewing of emotional pictures in 38 individuals with dysphoria and in 52 controls. Startle probes during picture viewing were presented at 300, 1500, 3500, 4500 ms after picture onset. Whereas controls showed the expected startle potentiation to unpleasant stimuli as compared to neutral and pleasant ones, individuals with dysphoria did not show any significant increase in startle reflex amplitude in response to unpleasant stimuli. Of note, startle potentiation during the viewing of unpleasant stimuli was significantly attenuated in the group with dysphoria relative to controls. Conversely, no significant effect concerning attentional startle modulation was noted. However, whereas individuals with dysphoria showed a prolonged cardiac deceleration when viewing unpleasant compared to neutral stimuli, the same effect was observed in controls only in the initial stage of stimuli processing. This study suggests that dysphoria is characterized by underactivation of the defensive motivational system and by prolonged attentional allocation to unpleasant stimuli. The assessment of affective startle modulation and cardiac deceleration is a valuable paradigm for unraveling dysfunctions in affective disposition and attention in dysphoria.
Topics: Affect; Attention; Depression; Emotions; Female; Heart Rate; Humans; Male; Reflex, Startle; Young Adult
PubMed: 32387705
DOI: 10.1016/j.brat.2020.103626 -
Scientific Reports Jan 2021Zebrafish is an established animal model for the reproduction and study of neurobiological pathogenesis of human neurological conditions. The 'startle reflex' in...
Zebrafish is an established animal model for the reproduction and study of neurobiological pathogenesis of human neurological conditions. The 'startle reflex' in zebrafish larvae is an evolutionarily preserved defence response, manifesting as a quick body-bend in reaction to sudden sensory stimuli. Changes in startle reflex habituation characterise several neuropsychiatric disorders and hence represent an informative index of neurophysiological health. This study aimed at establishing a simple and reliable experimental protocol for the quantification of startle reflex response and habituation. The fish were stimulated with 20 repeated pulses of specific vibratory frequency, acoustic intensity/power, light-intensity and interstimulus-interval, in three separate studies. The cumulative distance travelled, namely the sum of the distance travelled (mm) during all 20 stimuli, was computed as a group-level description for all the experimental conditions in each study. Additionally, by the use of bootstrapping, the data was fitted to a model of habituation with a first-order exponential representing the decay of locomotor distance travelled over repeated stimulation. Our results suggest that startle habituation is a stereotypic first-order process with a decay constant ranging from 1 to 2 stimuli. Habituation memory lasts no more than 5 min, as manifested by the locomotor activity recovering to baseline levels. We further observed significant effects of vibratory frequency, acoustic intensity/power and interstimulus-interval on the amplitude, offset, decay constant and cumulative distance travelled. Instead, the intensity of the flashed light did not contribute to significant behavioural variations. The findings provide novel insights as to the influence of different stimuli parameters on the startle reflex habituation and constitute a helpful reference framework for further investigation.
Topics: Acoustic Stimulation; Animals; Computer Simulation; Habituation, Psychophysiologic; Larva; Models, Animal; Reflex, Startle; Zebrafish
PubMed: 33436805
DOI: 10.1038/s41598-020-79923-6 -
Scientific Reports Aug 2023Two studies examined the amplitude of the startle response as a function of the Dark Tetrad of personality (narcissism, Machiavellianism, psychopathy, and sadism). We...
Two studies examined the amplitude of the startle response as a function of the Dark Tetrad of personality (narcissism, Machiavellianism, psychopathy, and sadism). We measured electromyographic activity of the orbicularis oculi muscle evoked by a startle stimulus while participants viewed images on a computer screen. Both studies revealed a negative correlation between general startle reactivity (averaged across positive, negative, and neutral images) and sadistic tendencies. In Study 2, all four dark traits were negative correlates of general startle reactivity. Study 2 also examined the personality correlates of aversive startle potentiation (ASP; indexed by greater reactivity while viewing negatively-valenced images than positive or neutral images). ASP correlated negatively with a variety of personality measures of psychopathy and sadism, their facets, and related personality tendencies (callousness, risk-taking, and restricted affect). These findings suggest that ordinary people with high levels of callousness and antagonism display physiological evidence of non-reactivity (i.e., blunted acoustic startle in general), whereas psychopathy and sadism are preferentially associated with reduced ASP.
Topics: Humans; Reflex, Startle; Sadism; Antisocial Personality Disorder; Personality Disorders; Personality
PubMed: 37648765
DOI: 10.1038/s41598-023-41043-2 -
Asian Journal of Psychiatry Nov 2022
Topics: Hallucinogens; Humans; Reflex, Startle; Somatoform Disorders
PubMed: 36202002
DOI: 10.1016/j.ajp.2022.103278 -
Current Opinion in Neurobiology Feb 2019Learning is essential for animal survival under changing environments. Even in its simplest form, learning involves interactions between a handful of neuronal circuits,... (Review)
Review
Learning is essential for animal survival under changing environments. Even in its simplest form, learning involves interactions between a handful of neuronal circuits, hundreds of neurons and many thousand synapses. In this review I will focus on habituation - a form of non-associative learning during which organisms decrease their response to repetitions of identical sensory stimuli. I will discuss how recent studies of the acoustic startle reflex mediated by the Mauthner cell in the zebrafish larva are helping to understand the neuroplastic processes that underlie habituation. In addition to being a fascinating biological process, habituation is clinically relevant because it is affected in various neuropsychiatric disorders in humans, including autism, schizophrenia, Fragile-X and Tourette's syndromes.
Topics: Acoustic Stimulation; Animals; Larva; Learning; Neuronal Plasticity; Reflex, Startle; Zebrafish
PubMed: 30359930
DOI: 10.1016/j.conb.2018.10.004 -
International Journal of... Sep 2022Intolerance of uncertainty (IU) is a key transdiagnostic feature of internalizing psychopathology. An increasing body of research suggests that IU is associated with...
OBJECTIVE
Intolerance of uncertainty (IU) is a key transdiagnostic feature of internalizing psychopathology. An increasing body of research suggests that IU is associated with increased psychophysiological reactivity in anticipation of unpredictable threat. However, most studies examining the psychophysiological correlates of IU have been conducted in adults. There is a critical need to understand the relationship between IU and psychophysiological reactivity in anticipation of unpredictable threat during adolescence, a key developmental period associated with increased exploration of situations with uncertain outcomes. Thus, the present study examined the association between (1) youth IU and (2) parental IU (as an indicator of risk) in relation to youth defensive motivation (startle reflex) and attention (startle probe N100 and P300) in anticipation of unpredictable threat.
METHODS
The sample included 193 13 to 22-year-old (M = 17.33, SD = 1.97) females and a biological parent. Participants and their parent completed a self-report measure of prospective and inhibitory IU. Youth startle potentiation, probe N100 enhancement, and probe P300 suppression (indicating increased attention to threat) were measured in anticipation of predictable and unpredictable threat.
RESULTS
Youth prospective IU and inhibitory IU were not related to youth psychophysiological reactivity to predictable or unpredictable threat. Greater parental prospective IU was associated with greater youth startle potentiation and probe N100 enhancement in anticipation of unpredictable threat.
CONCLUSION
The present study suggests that parental IU, but not concurrent IU, is associated with heightened defensive motivation and attentional engagement in anticipation of unpredictable threat in youth.
Topics: Adolescent; Adult; Anticipation, Psychological; Anxiety; Female; Humans; Mental Disorders; Motivation; Prospective Studies; Reflex, Startle; Uncertainty
PubMed: 35787438
DOI: 10.1016/j.ijpsycho.2022.06.017 -
Hearing Research Feb 2023The startle reflex (SR), a robust, motor response elicited by an intense auditory, visual, or somatosensory stimulus has been widely used as a tool to assess...
The startle reflex (SR), a robust, motor response elicited by an intense auditory, visual, or somatosensory stimulus has been widely used as a tool to assess psychophysiology in humans and animals for almost a century in diverse fields such as schizophrenia, bipolar disorder, hearing loss, and tinnitus. Previously, SR waveforms have been ignored, or assessed with basic statistical techniques and/or simple template matching paradigms. This has led to considerable variability in SR studies from different laboratories, and species. In an effort to standardize SR assessment methods, we developed a machine learning algorithm and workflow to automatically classify SR waveforms in virtually any animal model including mice, rats, guinea pigs, and gerbils obtained with various paradigms and modalities from several laboratories. The universal features common to SR waveforms of various species and paradigms are examined and discussed in the context of each animal model. The procedure describes common results using the SR across species and how to fully implement the open-source R implementation. Since SR is widely used to investigate toxicological or pharmaceutical efficacy, a detailed and universal SR waveform classification protocol should be developed to aid in standardizing SR assessment procedures across different laboratories and species. This machine learning-based method will improve data reliability and translatability between labs that use the startle reflex paradigm.
Topics: Humans; Rats; Mice; Animals; Guinea Pigs; Reflex, Startle; Acoustic Stimulation; Reproducibility of Results; Tinnitus; Disease Models, Animal; Gerbillinae
PubMed: 36566642
DOI: 10.1016/j.heares.2022.108667 -
Physiology & Behavior Oct 2016The 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)....
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.
Topics: Acoustic Stimulation; Adolescent; Adult; Affect; Analysis of Variance; Attention; Electromyography; Female; Humans; Male; Prepulse Inhibition; Psychiatric Status Rating Scales; Reflex, Startle; Stress, Psychological; Surveys and Questionnaires; Time Factors; Young Adult
PubMed: 27484698
DOI: 10.1016/j.physbeh.2016.07.022 -
Behavioural Brain Research Feb 2023Sensory-motor gating, the process of filtering sensory stimuli to modulate motor responses, is impaired in many psychiatric diseases but especially schizophrenia....
Sensory-motor gating, the process of filtering sensory stimuli to modulate motor responses, is impaired in many psychiatric diseases but especially schizophrenia. Sensory-motor gating assessed with the prepulse inhibition paradigm (PPI) measures startle in response to preceding acoustic stimuli. PPI studies in rodents have consistently found that neonatal hippocampal lesions impair sensory-motor gating in adult animals, but its applicability to primates has yet to be tested. The study examined acoustic startle responses and PPI in adult rhesus monkeys with neonatal lesions of the hippocampus (Neo-Hibo), amygdala (Neo-Aibo), and orbital frontal cortex areas 11 and 13 (Neo-Oasp) and with sham-operations (Neo-C). All monkeys were initially habituated to the startle apparatus and assayed for acoustic startle response curves. Subsequently, PPI was measured with the prepulse occurring at 60, 120, 240, 480, 1000 and 5000 msec prior to the pulse onset. No significant group differences in baseline startle were found. Compared to Neo-C monkeys, Neo-Hibo monkeys showed normal startle curves as well as normal PPI at short prepulse delays but prepulse facilitation (PPF) at longer prepulse intervals. Neo-Aibo monkeys displayed enhanced startle responses with only minor changes in PPI, whereas Neo-Oasp monkeys had severe dampening of startle responses and impaired PPI at shorter prepulse intervals. These results support prior evidence from rodent literature of the involvement of each of these areas in the development of the complex cortico-limbic circuit modulating sensory-motor gating and may shade light on the specific neural structures associated with deficits in PPI reported in neuropsychiatric disorders, such as schizophrenia, autism spectrum disorders, and post-traumatic disorders.
Topics: Animals; Prepulse Inhibition; Reflex, Startle; Amygdala; Acoustic Stimulation; Hippocampus; Frontal Lobe; Acoustics; Neural Inhibition
PubMed: 36283567
DOI: 10.1016/j.bbr.2022.114170 -
Neurological Sciences : Official... Oct 2022Tic related disorders affect 4-20% of the population, mostly idiopathic, can be grouped in a wide spectrum of severity, where the most severe end is Tourette Syndrome... (Review)
Review
Tic related disorders affect 4-20% of the population, mostly idiopathic, can be grouped in a wide spectrum of severity, where the most severe end is Tourette Syndrome (TS). Tics are arrhythmic hyperkinesias to whom execution the subject is forced by a "premonitory urge" that can be classified as sensory tic, just-right experience or urge without obsession. If an intact volitional inhibition allows patients to temporarily suppress tics, a lack or deficit in automatic inhibition is involved in the genesis of the disorder. Studies have assessed the presence of intrinsic microscopic and macroscopic anomalies in striatal circuits and relative cortical areas in association with a hyperdopaminergic state in the basal forebrain. Prepulse inhibition (PPI) of the startle reflex is a measure of inhibitory functions by which a weak sensory stimulus inhibits the elicitation of a startle response determined by a sudden intense stimulus. It is considered an operation measure of sensorimotor gating, a neural process by which unnecessary stimuli are eliminated from awareness. Evidence points out that the limbic domain of the CSTC loops, dopamine and GABA receptors within the striatum play an important role in PPI modulation. It is conceivable that a sensorimotor gating deficit may be involved in the genesis of premonitory urge and symptoms. Therefore, correcting the sensorimotor gating deficit may be considered a target for tic-related disorders therapies; in such case PPI (as well as other indirect estimators of sensorimotor gating) could represent therapeutic impact predictors.
Topics: Humans; Prepulse Inhibition; Reflex, Startle; Sensory Gating; Tics; Tourette Syndrome
PubMed: 35781754
DOI: 10.1007/s10072-022-06235-0