Cardiac timing and threatening stimuli influence response inhibition and ex-Gaussian parameters of reaction time in a Go/No-go task.

Sensorimotor responses vary as a function of the cardiac cycle phase. These effects, known as cardiac cycle time effects, have been explained by the inhibition of cardiac afferent signals on information processing. However, the validity of cardiac cycle time effects is challenged by mixed findings. Factors such as current information processing and affective context may modulate cardiac cycle time effects and account for inconsistencies in the literature. The current study examines the influence of cardiac cycle time and threatening stimuli on two aspects of sensorimotor processing, response speed and inhibition. Thirty-four participants (Mage  = 19.35 years; 29 female) completed an auditory Go/No-go task in no face, neutral face, and fearful face conditions. Faces were presented at either cardiac diastole or systole. Participants' reaction times (RTs) during Go trials and failures in response inhibition during No-go trials were recorded. The ex-Gaussian model was fit to RT data in each condition deriving the parameters, mu (µ) and tau (τ), that indicate response speed and attentional lapses, respectively. Repeated measures ANOVA were used to analyze behavioral data. Results showed that cardiac systole prolonged µ but decreased τ, and that cardiac diastole reduced inhibition errors in the fearful face condition but not in other conditions. These findings indicate that cardiac timing differentially modulates sensory-perceptual and top-down attentional processes and cardiac timing interacts with threatening contexts to influence response inhibition. These results highlight the specificity of cardiac cycle time effects on sensorimotor processing.

"Generalized unsafety" as fear inhibition to safety signals in adults with and without childhood trauma.

The Generalized Unsafety Theory of Stress posits that low heart rate variability contributes to a perception of "generalized unsafety" (i.e., constantly perceiving oneself to be unsafe), independent of stressful events or stress-related symptomatology. We tested this claim by examining if resting heart rate variability, trait worry, posttraumatic stress symptoms, trauma history, and age of onset predicted fear inhibition, a measure of generalized unsafety. A Pavlovian discriminant conditioning paradigm was used to assess fear inhibition level by comparing eyeblink startle potentiation to a threat cue (presented with air blast) with startle potentiation to a safety signal (never presented with air blast). Survey and laboratory responses were collected from 42 adults who were 20 years old on average, 86% Women, and 76% White. Heart rate variability did not independently predict variation in fear inhibition, as hypothesized. Rather, higher levels of posttraumatic stress symptoms and greater cumulative interpersonal trauma predicted lower fear inhibition. Individuals reporting childhood trauma had higher trait worry, which predicted more severe posttraumatic stress symptoms. These findings highlight the role of attenuated inhibitory learning in stress-related symptomatology and developmentally disruptive trauma. Ability to distinguish threat from safety is a plausible biobehavioral mechanism by which adversity impacts development.

Gender differences in the relationship between resting heart rate variability and 24-hour blood pressure variability.

The study explored the relationship between time- and frequency-domain indices of cardiac autonomic control and 24 h blood pressure variability (BPV) in a sample of healthy men and women. Vagally mediated cardiac control was inversely related to 24 h BPV, and measures of cardiac autonomic control were better predictors of systolic BPV in men and better predictors of diastolic BPV in women. These findings may help researchers to understand the disparity in cardiovascular disease morbidity and mortality between men and women.

Respiratory sinus arrhythmia: a marker for positive social functioning and receptive language skills in children with autism spectrum disorders.

The current study builds on the emerging autism spectrum disorder (ASD) literature that associates autonomic nervous system activity with social function, and examines the link between respiratory sinus arrhythmia (RSA) and both social behavior and cognitive function. The RSA response pattern was assessed in 23 4- to 7-year-old children diagnosed with an ASD. Higher baseline RSA amplitudes were associated with better social behavior (i.e., more conventional gestures, more instances of joint attention) and receptive language abilities. Similar to reports of typically developing children, ASD children with higher RSA amplitude at baseline showed greater RSA and HP reactivity during an attention-demanding task. These results highlight the importance of studying RSA as a marker of positive function in children with ASD.

Participant diversity in Psychophysiology.

The Society for Psychophysiological Research and accompanying journal, Psychophysiology, have increasingly incorporated diversity and inclusion into their posted values, conference programming, and science. Much of this focus on equity, diversity, and inclusion work has occurred since 2010. The current review content analyzed the articles published in Psychophysiology from 2010 through 2020 to determine if SPR and Psychophysiology's commitment to diversity and inclusion has resulted in changes to reporting and analysis of participant demographics. Demographic reporting practices were compared to APA reporting standards and the use of demographic variables assessed according to the guidance proffered in the introduction to Psychophysiology's 2016 Special Issue on Diversity and Representation. Results of the content analysis indicated near perfect reporting of biological sex and frequent reporting of average age. Age range and educational attainment were reported in over half of studies, while race or ethnicity were reported in only 17%. Socioeconomic status, income, gender identity, and sexual orientation were almost never reported. In over 60% of studies at least one major demographic variable was reported, but was not used in preliminary, main, or supplementary analyses as a covariate, moderator, or otherwise. SPR and Psychophysiology should continue advocating for increased reporting of major demographic variables and ethical analysis of demographic modulation of various psychophysiological mechanisms. We provide a preliminary template of reporting standards and call for the inclusion of more open science practices by psychophysiologists.

How Long Is Long Enough? Controlling for Acute Caffeine Intake in Cardiovascular Research.

Caffeine substantially affects cardiovascular functioning, yet wide variability exists in caffeine control procedures in cardiovascular reactivity research. This study was conducted in order to identify a minimal abstention duration in habitual coffee consumers whereby cardiovascular reactivity is unconfounded by caffeine; Six hours (caffeine's average half-life) was hypothesized. Thirty-nine subjects (mean age: 20.9; 20 women) completed a repeated measures study involving hand cold pressor (CP) and memory tasks. Caffeinated and decaffeinated coffee were administered. The following cardiovascular indices were acquired during pre-task, task, and post-task epochs prior to coffee intake, 30 min-, and six hours post-intake: Heart rate (HR), high-frequency heart rate variability (HF-HRV), root mean squared successive differences (RMSSD), systolic and diastolic blood pressures (SBP, DBP), mean arterial pressure (MAP), pre-ejection period (PEP), left ventricular ejection time (LVET), systemic vascular resistance (SVR), systemic vascular resistance index (SVRI). Results support the adequacy of a six-hour abstention in controlling for caffeine-elicited cardiovascular changes. The current study offers a suggested guideline for caffeine abstention duration in cardiovascular research in psychophysiology. Consistent practice in caffeine abstention protocols would promote validity and reliability across such studies.

Comparison between the Effects of Acute Physical and Psychosocial Stress on Feedback-Based Learning.

Stress modulates feedback-based learning, a process that has been implicated in declining mental function in aging and mental disorders. While acute physical and psychosocial stressors have been used interchangeably in studies on feedback-based learning, the two types of stressors involve distinct physiological and psychological processes. Whether the two types of stressors differentially influence feedback processing remains unclear. The present study compared the effects of physical and psychosocial stressors on feedback-based learning. Ninety-six subjects (Mage = 19.11 years; 50 female) completed either a cold pressor task (CPT) or mental arithmetic task (MAT), as the physical or psychosocial stressor, while electrocardiography and blood pressure were measured to assess cardiovascular stress reactivity (CVR). Self-ratings on the emotional valence of the stressors were also obtained. A probabilistic learning task was given prior to and after the stressors. Accuracy in selecting positive (Go accuracy) and avoiding negative stimuli (No-go accuracy) were recorded as learning outcomes. Repeated measures ANOVA and multiple regressions were used to compare the effects of two stressors and examine the effects of CVR and valence on the learning outcomes. The results showed that although the effects of CPT and MAT on feedback processing were not different, CVR and valence influenced Go and No-go accuracy, respectively. The results suggest that stress-modulated feedback-based learning involves multiple pathways and underscore the link between CVR and reward sensitivity. The findings have clinical implications and may contribute to a better understanding of human behavioral systems.

Only time will tell: Acute stress response patterns with time series analysis.

Acute stress is often conceptualized as a response pattern that activates the fight-or-flight response via the sympathetic nervous system (SNS). However, other stress response patterns can manifest as well, such as parasympathetic nervous system (PNS) shutdown, and SNS-PNS coactive hypervigilance. Each response pattern engages many dimensions, including physiological, emotional, and behavioral. As stress unfolds over time, these patterns can change to adjust to the changing nature of the stressor. This proof of concept study introduces novel time series methodology to track the multidimensional patterns of acute stress. The defense cascade provides a model with which to understand and predict response patterns over the time course of an acute stressor. The time series methodology introduced in this study holds promise for identifying mechanisms of change in therapy and clinical settings.

Resting heart rate variability modulates the effects of concurrent working memory load on affective startle modification.

Vagally mediated heart rate variability (vmHRV) is thought to index top-down control processes in emotion regulation. According to the Generalized Unsafety Theory of Stress (GUTS), resting vmHRV indexes top-down resources that are needed to inhibit subcortical threat circuits, which is important for context-appropriate affective responding. Although this notion has been supported by studies of affective startle (SR) modification, direct evidence that top-down resources are the linking mechanism between vmHRV and context-appropriate affective responding has been lacking. To investigate this possible mechanism, college-aged participants (n = 92) were recruited to complete a picture viewing task and a concurrent working memory (WM) task. Concurrent WM load was manipulated, and the auditory SR stimulus was delivered while viewing affective pictures. Electrocardiography and electromyography were recorded to assess vmHRV and SR eyeblink, respectively. Results showed that WM load attenuated affective SR modification. As expected, the attenuating effects of load on affective SR modification were stronger among low vmHRV relative to high vmHRV individuals, indicating that vmHRV is linked to context-appropriate affective responding through the mechanism of top-down resources. These results support the GUTS and suggest that atypical affective responding among low vmHRV individuals is attributed to the lack of WM resources. Our findings highlight the relation between vmHRV and top-down resources that have been implicated in emotion regulation and contribute to a better understanding of emotion dysregulation in psychopathology.

Comparison of Functional Connectivity in the Prefrontal Cortex during a Simple and an Emotional Go/No-Go Task in Female versus Male Groups: An fNIRS Study.

Inhibitory control is a cognitive process to suppress prepotent behavioral responses to stimuli. This study aimed to investigate prefrontal functional connectivity during a behavioral inhibition task and its correlation with the subject's performance. Additionally, we identified connections that are specific to the Go/No-Go task. The experiment was performed on 42 normal, healthy adults who underwent a vanilla baseline and a simple and emotional Go/No-Go task. Cerebral hemodynamic responses were measured in the prefrontal cortex using a 16-channel near infrared spectroscopy (NIRS) device. Functional connectivity was calculated from NIRS signals and correlated to the Go/No-Go performance. Strong connectivity was found in both the tasks in the right hemisphere, inter-hemispherically, and the left medial prefrontal cortex. Better performance (fewer errors, faster response) is associated with stronger prefrontal connectivity during the simple Go/No-Go in both sexes and the emotional Go/No-Go connectivity in males. However, females express a lower emotional Go/No-Go connectivity while performing better on the task. This study reports a complete prefrontal network during a simple and emotional Go/No-Go and its correlation with the subject's performance in females and males. The results can be applied to examine behavioral inhibitory control deficits in population with neurodevelopmental disorders.

Interplay between state anxiety, heart rate variability, and cognition: An ex-Gaussian analysis of response times.

The present study employed an ex-Gaussian model of response times (RTs) to elucidate the cognitive processes related to experimentally induced state anxiety (SA) and vagally mediated heart rate variability (vmHRV), an indicator of adaptive responses in both cognitive and affective domains. Participants (n = 110) completed a dual task composed of (i) a flanker attention and (2) working memory load task, while SA was induced by threat of noise. Electrocardiography was measured during the dual task and during four baseline periods in order to calculate vmHRV. RTs on the flanker task were fit to an ex-Gaussian distribution, which estimated three RT parameters: mu (Gaussian mean), sigma (Gaussian SD), and tau (combination of exponential mean and SD). First, findings indicate that threat of noise was associated with reductions in mu and tau, suggesting that SA might improve attention and motor responding. Second, higher resting vmHRV was associated with lower tau (averaged across conditions) and stronger threat-related decreases in tau. Third, intra-individual decreases in vmHRV were accompanied by concomitant decreases in tau. These findings support roles for trait and state vagal control in guiding adaptive anxiety-related (and anxiety-unrelated) attentional responses. Findings are consistent with extant theories that emphasize functional interrelations among emotion, cognition, and vagal function.

Probing Neurovisceral Integration via Functional Near-Infrared Spectroscopy and Heart Rate Variability.

The neurovisceral integration model (NVM) proposes that an organism's ability to flexibly adapt to its environment is related to biological flexibility within the central autonomic network (CAN). One important aspect of this flexibility is behavioral inhibition (Thayer and Friedman, 2002). During a behavioral inhibition task, the CAN, which comprises a series of feedback loops, must be able to integrate information and react to these inputs flexibly to facilitate optimal performance. The functioning of the CAN is shown to be associated with respiratory sinus arrhythmia (RSA), as the vagus nerve is part of this feedback system. Although the NVM has been examined through neural imaging and RSA, only a few studies have examined these measures simultaneously during the neuroimaging procedure. Furthermore, these studies were done at rest or used tasks that were not targeted at processes associated with the NVM, such as behavioral inhibition and cognitive flexibility. For this reason, the present study assessed RSA and neural activation in the pre-frontal cortex simultaneously while participants completed a behavior inhibition task. RSA and functional near-infrared spectroscopy were collected in 38 adults, and resting levels of pre-frontal activation were negatively related to RSA, but pre-frontal activation during the behavior inhibition task was not. The negative relationship between RSA and oxygenated hemoglobin is consistent with previous functional magnetic resonance imaging work examining the NVM at baseline and should be further studied. Additional research investigating how this relationship may change based on task demands or environmental contexts would help clarify the applicability of the model.

Restricted repetitive behaviors in autism spectrum disorder: A systematic review from the neurovisceral integration perspective.

The neurovisceral integration model posits that cognitive-behavioral inflexibility arises from biological inflexibility of feedback loops within the central autonomic network. The parasympathetic nervous system (PNS) is integral in this network. Activity of the PNS, which is normally tonically inhibited, can be indexed through respiratory sinus arrhythmia (RSA). When the PNS becomes disinhibited, indicating decreased flexibility within the network, RSA is reduced and cognitive-behavioral flexibility is impaired. Using this theoretical framework, cognitive-behavioral inflexibility is discussed from the Research Domain Criteria (RDoC) perspective. Restricted repetitive behaviors in autism spectrum disorder (ASD) are proposed as exemplars of cognitive-behavioral inflexibility, and behavioral and RSA literature in ASD are reviewed. RSA differences and their relation to inflexibility in ASD are discussed to support the model and to propose RSA as a biomarker for cognitive-behavioral inflexibility. Considerations for future research are discussed, in addition to implications the model might have on assessment and transdiagnostic treatment practices.

Autonomic response in autism spectrum disorder: Relationship to social and cognitive functioning.

Individuals with autism spectrum disorder (ASD) may exhibit chronic autonomic nervous system (ANS) hyperarousal (e.g., lower respiratory sinus arrhythmia and higher heart rate) compared to their typically developing peers, reflecting a chronic biological threat response. The sustained nature of this cardiac threat suggests tonic nervous system perception of threat in safe contexts. Herein, the cardiac literature in adult and child populations with ASD is reviewed and placed within a continuum of functioning in order to inform the relationship between cardiac response and functioning in ASD. Findings from this review support the relationship between chronic autonomic hyperarousal and emotional and behavioral difficulties observed in individuals with ASD.

Physiological feelings.

The role of peripheral physiology in the experience of emotion has been debated since the 19th century following the seminal proposal by William James that somatic responses to stimuli determine subjective emotion. Subsequent views have integrated the forebrain's ability to initiate, represent and simulate such physiological events. Modern affective neuroscience envisions an interacting network of "bottom-up" and "top-down" signaling in which the peripheral (PNS) and central nervous systems both receive and generate the experience of emotion. "Feelings" serves as a term for the perception of these physical changes whether emanating from actual somatic events or from the brain's representation of such. "Interoception" has come to represent the brain's receipt and representation of these actual and "virtual" somatic changes that may or may not enter conscious awareness but, nonetheless, influence feelings. Such information can originate from diverse sources including endocrine, immune and gastrointestinal systems as well as the PNS. We here examine physiological feelings from diverse perspectives including current and historical theories, evolution, neuroanatomy and physiology, development, regulatory processes, pathology and linguistics.

P50 sensory gating and attentional performance.

Sensory gating refers to the preattentional filtering of irrelevant sensory stimuli. This process may be impaired in schizotypy, which is a trait also associated with cigarette smoking. This association may in part stem from the positive effects of smoking on sensory gating and attention. The relationship among sensory gating, smoking, schizotypy and attention was examined in 39 undergraduates. Sensory gating was indexed by the P50 suppression paradigm, and attention was measured by the Attention Network Test (ANT) and a Stroop task. Results showed sensory gating to be positively correlated with performances on ANT and Stroop reflected in better alerting, less conflict between stimuli, faster reaction time, and greater accuracy. Smokers showed a pattern of a greater number of significant correlations between sensory gating and attention in comparison to non-smokers, although the relationship between sensory gating and attention was not affected by schizotypy. The majority of significant correlations were found in the region surrounding Cz. These findings are discussed relative to the potential modifying influence of smoking and schizotypy on sensory gating and attention.

Controlling for caffeine in cardiovascular research: A critical review.

Caffeine, the most widely consumed drug in the world, exerts numerous effects on cardiovascular activity. Thus, it is important and advisable to control for caffeine consumption in studies examining caffeine and/or cardiovascular activity and reactivity. This paper 1) reviews the literature concerning caffeine's effects on cardiovascular parameters; 2) summarizes the widely varying protocols used to control for the drug in extant cardiovascular literature, and 3) provide guidelines for caffeine control procedures to minimize potentially confounding acute and withdrawal effects of the drug. An abstention period equal to the average half-life of the drug is recommended for creation of methodological controls for caffeine. Additional methodological recommendations are described concerning factors that moderate the half-life of caffeine. When feasible, researchers should consider and aim to control for caffeine's acute and extended psychophysiological effects. This understudied issue has fundamental implications for caffeine-related investigations and research in psychophysiology and behavioral medicine.

An autonomic flexibility-neurovisceral integration model of anxiety and cardiac vagal tone.

Research on heart rate variability (HRV), cardiac vagal tone, and their relationship to anxiety is reviewed in the context of the autonomic flexibility and neurovisceral integration models of adaptive functioning. These perspectives address the qualities of response flexibility and inhibition across multiple levels, incorporating central and autonomic nervous system mechanisms of environmental engagement, as well as principles derived from non-linear dynamics. These models predict reduced HRV and vagal tone in anxiety, and the literature has generally supported this prediction, with exceptions as are noted. State, trait, and clinical expressions of anxiety are considered, along with the clinical, methodological, and theoretical implications of this research. A portrayal of anxiety as a restricted response range across biological and behavioral realms of functioning is drawn from the literature on anxiety and HRV.

Autonomic characteristics of defensive hostility: reactivity and recovery to active and passive stressors.

The autonomic characteristics of hostility and defensiveness were assessed in 55 male undergraduates based on composite Cook Medley Hostility (Chost) and Marlowe Crowne Social Desirability (MC) scores to create 4 groups: Defensive Hostile (DH; high MC, high Chost), High Hostile (HH; low MC, high Chost), Defensive (Def; high MC, low Chost) and Low Hostile (LH; low MC, low Chost). All subjects engaged in a video game (VG) and hand cold pressor (CP) task. Cardiovascular responses in DH subjects were predicted to show enhanced sympathetic alpha and beta-adrenergic activity and the least vagal control compared to others across tasks. DH and LH men showed significant heart rate reactivity to the CP task compared to HH men. LH men showed significant reductions in high frequency power (vagal assessment) to the tasks compared to HH men. Future studies may employ harassment techniques and include the factors of gender and ethnicity in their assessments.

Individual differences in behavioral activation and cardiac vagal control influence affective startle modification.

The startle response (SR) has a close relationship with stress responses. Startle modification (SRM) has been widely used to study stress disorders (e.g., posttraumatic stress disorder). The framework of the behavioral inhibition and activation systems (BIS/BAS) has been thought to correspond with withdrawal and approach motivational processes underlying affective SRM and can influence stress reactivity. Vagally-mediated cardiac activity as indexed by heart rate variability (HRV) has been associated with SRM and regulatory processes during stress. In the present study, the influence of individual differences in the BIS/BAS and resting HRV on affective SRM were examined. Eighty-six subjects viewed affective pictures while acoustic SR stimuli were delivered. Individual differences in motivation were measured by the BIS/BAS scales. The magnitude of SR was assessed as electromyographic activity of the SR eyeblink during pictures of different valences. Resting HRV was derived from electrocardiography. In contrast to previous studies, the present results showed that startle inhibition and potentiation were related to BAS and HRV, but not to BIS. There was also an interaction of BAS and HRV, indicating that the relationship between HRV and SRM strengthened as BAS scores decreased. The present findings suggest that BAS may relate to both withdrawal and approach, and trait stress reactivity is influenced by BAS and cardiac vagal activity. In addition, BAS moderates the relationship between cardiac vagal activity and SRM. These findings have both theoretical and practical implications for the study of SRM, stress disorders, and health.