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Physiology & Behavior Jan 2015This study evaluated differences in the amplitude of startle reflex and Sensitivity to Reward (SR) and Sensitivity to Punishment (SP) personality variables of the...
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.
Topics: Blinking; Electromyography; Emotions; Eyelids; Female; Humans; Muscle, Skeletal; Personality; Photic Stimulation; Psychological Tests; Reflex, Startle; Reinforcement, Psychology; Reward; Surveys and Questionnaires; Visual Perception; Young Adult
PubMed: 25447471
DOI: 10.1016/j.physbeh.2014.09.009 -
The Journal of Maternal-fetal &... Nov 2016The aim of this study is to provide an extensive overview of the clinical features of neonatal paroxysmal motor phenomena, both self-limited, related to the immaturity... (Review)
Review
OBJECTIVE
The aim of this study is to provide an extensive overview of the clinical features of neonatal paroxysmal motor phenomena, both self-limited, related to the immaturity of the central nervous system, and pathological (epileptic and non-epileptic), in order to help the diagnostic approach.
METHODS
We reviewed the scientific literature about epileptic and non-epileptic paroxysmal motor phenomena in newborns.
RESULTS
Paroxysmal motor phenomena in newborns represent a challenge for the clinicians due to the different underlying pathophysiological mechanisms. A proper differential diagnosis is required.
CONCLUSIONS
There are some clinical features that may help clinicians with the differentiation among physiological and pathological, epileptic, and non-epileptic events. However, further investigations are often needed to identify the cause. A continuous synchronized video-electroencephalogram (EEG)-recording, interpreted by an expert in neonatal neurology, remains the gold standard to prove the epileptic origin of a paroxysmal motor phenomenon.
Topics: Diagnosis, Differential; Dyskinesias; Electroencephalography; Epilepsy; Humans; Infant, Newborn; Reflex, Startle; Video Recording
PubMed: 26918366
DOI: 10.3109/14767058.2016.1140735 -
Neuroscience and Biobehavioral Reviews May 2023The startle response consists of whole-body muscle contractions, eye-blink, accelerated heart rate, and freezing in response to a strong, sudden stimulus. It is... (Review)
Review
The startle response consists of whole-body muscle contractions, eye-blink, accelerated heart rate, and freezing in response to a strong, sudden stimulus. It is evolutionarily preserved and can be observed in any animal that can perceive sensory signals, indicating the important protective function of startle. Startle response measurements and its alterations have become a valuable tool for exploring sensorimotor processes and sensory gating, especially in the context of pathologies of psychiatric disorders. The last reviews on the neural substrates underlying acoustic startle were published around 20 years ago. Advancements in methods and techniques have since allowed new insights into acoustic startle mechanisms. This review is focused on the neural circuitry that drives the primary acoustic startle response in mammals. However, there have also been very successful efforts to identify the acoustic startle pathway in other vertebrates and invertebrates in the past decades, so at the end we briefly summarize these studies and comment on the similarities and differences between species.
Topics: Animals; Reflex, Startle; Acoustic Stimulation; Mammals
PubMed: 36914078
DOI: 10.1016/j.neubiorev.2023.105129 -
Medical Hypotheses Oct 2020Prepulse inhibition (PPI) of acoustic startle reflex is a measure of sensorimotor gating that may reflect the biological processes underlying gaiting impairments in...
Prepulse inhibition (PPI) of acoustic startle reflex is a measure of sensorimotor gating that may reflect the biological processes underlying gaiting impairments in schizophrenia. Although PPI is clinically useful, why PPI is inhibited in schizophrenia is largely unknown. Prepulse inhibition is mediated by M2-like muscarinic acetylcholine receptor on neurons in the caudal pontine reticular nucleus (PnC), activation of this receptor induces Gαi dissociation, and inhibits adenylyl cyclase, resulting in the inhibition of the neurons. On the other hand, the symptoms of schizophrenia are mainly linked to hyperactive dopaminergic activity, mediated by dopamine D2-like receptor. Interestingly, D2-like receptor also uses Gαi. This means that both M2-like acetylcholine receptor and D2-like dopamine receptor use same Gαi-protein, competitively. Thus, chronic over-activation of D2-like receptor observed in schizophrenia may disrupt normal M2-like acetylcholine receptor functions due to their shared coupling to Gαi-proteins, i.e. by reducing the amount of Gαi-protein available for M2-like acetylcholine receptors, resulting in the impairment of PPI.
Topics: Acoustic Stimulation; Humans; Prepulse Inhibition; Receptors, Dopamine; Reflex, Startle; Schizophrenia
PubMed: 32502900
DOI: 10.1016/j.mehy.2020.109901 -
Psychophysiology Dec 2023The startle response is a cross-species defensive reflex that is considered a key tool for cross-species translational emotion research. While the neural pathway... (Review)
Review
The startle response is a cross-species defensive reflex that is considered a key tool for cross-species translational emotion research. While the neural pathway mediating (affective) startle modulation has been extensively studied in rodents, human work on brain-behavior interactions has lagged in the past due to technical challenges, which have only recently been overcome through non-invasive simultaneous EMG-fMRI assessments. We illustrate key paradigms and methodological tools for startle response assessment in rodents and humans and review evidence for primary and modulatory neural circuits underlying startle responses and their affective modulation in humans. Based on this, we suggest a refined and integrative model for primary and modulatory startle response pathways in humans concluding that there is strong evidence from human work on the neurobiological pathway underlying the primary startle response while evidence for the modulatory pathway is still sparse. In addition, we provide methodological considerations to guide future work and provide an outlook on new and exciting perspectives enabled through technical and theoretical advances outlined in this work.
Topics: Humans; Reflex, Startle; Electromyography; Brain; Emotions
PubMed: 37402156
DOI: 10.1111/psyp.14364 -
Schizophrenia Research Oct 2020Latency of the acoustic startle reflex is the time from presentation of the startling stimulus until the response, and provides an index of neural processing speed....
BACKGROUND
Latency of the acoustic startle reflex is the time from presentation of the startling stimulus until the response, and provides an index of neural processing speed. Schizophrenia subjects exhibit slowed latency compared to healthy controls. One prior publication reported significant heritability of latency. The current study was undertaken to replicate and extend this solitary finding in a larger cohort.
METHODS
Schizophrenia probands, their relatives, and control subjects from the Consortium on the Genetics of Schizophrenia (COGS-1) were tested in a paradigm to ascertain magnitude, latency, and prepulse inhibition of startle. Trial types in the paradigm were: pulse-alone, and trials with 30, 60, or 120 ms between the prepulse and pulse. Comparisons of subject groups were conducted with ANCOVAs to assess startle latency and magnitude. Heritability of startle magnitude and latency was analyzed with a variance component method implemented in SOLAR v.4.3.1.
RESULTS
980 subjects had analyzable startle results: 199 schizophrenia probands, 456 of their relatives, and 325 controls. A mixed-design ANCOVA on startle latency in the four trial types was significant for subject group (F(2,973) = 4.45, p = 0.012) such that probands were slowest, relatives were intermediate and controls were fastest. Magnitude to pulse-alone trials differed significantly between groups by ANCOVA (F(2,974) = 3.92, p = 0.020) such that controls were lowest, probands highest, and relatives intermediate. Heritability was significant (p < 0.0001), with heritability of 34-41% for latency and 45-59% for magnitude.
CONCLUSION
Both startle latency and magnitude are significantly heritable in the COGS-1 cohort. Startle latency is a strong candidate for being an endophenotype in schizophrenia.
Topics: Acoustic Stimulation; Acoustics; Humans; Prepulse Inhibition; Reflex, Startle; Schizophrenia
PubMed: 33189519
DOI: 10.1016/j.schres.2020.11.003 -
Journal of Anxiety Disorders Jan 2022The clinical presentation of anxiety may differ between Hispanics/Latinx (H/L) and non-H/L, although findings on ethnic differences in self-reported anxiety symptoms...
The clinical presentation of anxiety may differ between Hispanics/Latinx (H/L) and non-H/L, although findings on ethnic differences in self-reported anxiety symptoms have been mixed. Fewer studies have focused on ethnic differences in quick and relatively automatic laboratory-assessed indicators of anxiety symptoms, which have the potential to be more objective indicators than self-report. Therefore, the present study examined ethnic differences in two laboratory-assessed indicators of threat sensitivity (an important transdiagnostic mechanism of anxiety): attentional bias to threat and electromyography startle reactivity to threat. White H/L (n = 117) and White non-H/L (n = 168) adults who were matched on demographics and lifetime psychopathology (including anxiety) completed a dot-probe task to assess attentional bias to threat and the No-Predictable-Unpredictable threat (NPU) task to assess startle reactivity to threat. Results indicated that H/L displayed less Slow Orientation (β = -0.27, p = 0.032, R = 0.02), and increased Slow Disengagement (β = 0.31, p = 0.016, R = 0.02) compared to non-H/L. H/L exhibited blunted overall startle compared to non-H/L (β = -0.30, p = 0.014, R = 0.02), but groups did not differ in startle reactivity to either predictable or unpredictable threat. In summary, H/L and non-H/L may differ in their experience and presentation of anxiety symptoms and such differences may vary across indicators of sensitivity to threat.
Topics: Adult; Anxiety; Anxiety Disorders; Fear; Humans; Reflex, Startle; Self Report
PubMed: 34864540
DOI: 10.1016/j.janxdis.2021.102508 -
Behaviour Research and Therapy May 2018Although avoidance and escape behaviors each contribute to maintaining anxiety disorders, only avoidance completely eliminates exposure to the aversive context. Current...
Although avoidance and escape behaviors each contribute to maintaining anxiety disorders, only avoidance completely eliminates exposure to the aversive context. Current research compared anticipatory defensive engagement when aversion could either be completely avoided or escaped after initial exposure; in addition, this research examined the impact of trait anxiety on coping-related defensive engagement. Cues signaled that upcoming rapid action would avoid (block), escape (terminate), or not affect subsequent aversive exposure; the acoustic startle reflex was measured during each anticipatory interval to index defensive engagement, and blink magnitudes were compared across low-, moderate-, and high-anxious individuals. For all participants, startle was potentiated when aversive exposure was uncontrollable and attenuated when aversion was avoidable. On escape trials, on the other hand, startle potentiation increased with rising participant anxiety. Results suggest 1) defensive engagement is generally reduced in avoidance contexts relative to contexts in which exposure is certain, and; 2) trait anxiety increases defensive engagement specifically when aversive exposure can be controlled but remains certain.
Topics: Adolescent; Anxiety; Autonomic Nervous System; Fear; Female; Galvanic Skin Response; Heart Rate; Humans; Male; Reaction Time; Reflex, Startle; Young Adult
PubMed: 29549752
DOI: 10.1016/j.brat.2018.03.002 -
Neurophysiologie Clinique = Clinical... May 2015We aimed to analyze functional changes at brainstem and spinal levels in essential tremor (ET), Parkinson's disease (PD) and coexisting essential tremor and Parkinson's...
OBJECTIVE
We aimed to analyze functional changes at brainstem and spinal levels in essential tremor (ET), Parkinson's disease (PD) and coexisting essential tremor and Parkinson's disease (ET-PD).
PATIENTS AND METHOD
Age- and gender-matched patients with tremor (15 ET, 7 ET with resting tremor, 25 ET-PD and 10 PD) and 12 healthy subjects were enrolled in the study. Diagnosis was established according to standardized clinical criteria. Electrophysiological studies included blink reflex (BR), auditory startle reaction (ASR) and long latency reflex (LLR).
RESULTS
Blink reflex was normal and similar in all groups. Probability of ASR was significantly lower in ET-PD group whereas it was similar to healthy subjects in ET and PD (P<0.001). LLR was recorded during voluntary activity in all three groups. LLR II was more common in ET, PD and ET-PD groups. LLR III was far more common in the PD group (n=3, 13.6% in ET; n=4, 16.0% in ET-PD and n=7, 46.7% in PD; p=0.037).
CONCLUSIONS
Despite the integrity of BR pathways, ASR and LLR show distinctive abnormalities in ET-PD. In our opinion, our electrophysiological findings support the hypothesis that ET-PD is a distinct entity.
Topics: Aged; Blinking; Brain Stem; Essential Tremor; Female; Humans; Male; Middle Aged; Parkinson Disease; Pyramidal Tracts; Reflex, Abnormal; Reflex, Startle
PubMed: 25892331
DOI: 10.1016/j.neucli.2015.01.001 -
Neuroscience Letters Jul 2019Hyperacusis may be defined as diminishing tolerance to moderate and high intensity sounds in people with normal hearing sensitivity. Serotonin plays a critical role in...
Hyperacusis may be defined as diminishing tolerance to moderate and high intensity sounds in people with normal hearing sensitivity. Serotonin plays a critical role in some of auditory tasks including startle reflex and prepulse inhibition. Serotonin deficiency can cause some diseases which can coincide with hyperacusis. The aim of the present study was to investigate the probable influence of serotonergic depletion in nucleus accumbens (NAcc) on the startle reflex. The startle reflexes were examined in Wistar rats (n: 48) in different intensities with and without the background noise. The amplitude of startle reflex significantly increased in NAcc-injected rats without background noise, while this difference disappeared in the presence of background noise in all intensities. These data proposed that the injection of 5, 7-Dihydroxytryptamine (5, 7-DHT) into nucleus accumbens will cause hyperacusis-like behavior, and strengthens the possibility of the role of serotonin and nucleus accumbens in hyperacusis.
Topics: 5,7-Dihydroxytryptamine; Acoustic Stimulation; Animals; Hyperacusis; Injections, Intraventricular; Male; Nucleus Accumbens; Rats; Reflex, Startle
PubMed: 30970270
DOI: 10.1016/j.neulet.2019.01.040