Changes In Autonomic Responses Research Articles

Auditory aversive generalization learning prompts threat-specific changes in alpha-band activity.

Pairing a neutral stimulus with aversive outcomes prompts neurophysiological and autonomic changes in response to the conditioned stimulus (CS+), compared to cues that signal safety (CS-). One of these changes-selective amplitude reduction of parietal alpha-band oscillations-has been reliably linked to processing of visual CS+. It is, however, unclear to what extent auditory conditioned cues prompt similar changes, how these changes evolve as learning progresses, and how alpha reduction in the auditory domain generalizes to similar stimuli. To address these questions, 55 participants listened to three sine wave tones, with either the highest or lowest pitch (CS+) being associated with a noxious white noise burst. A threat-specific (CS+) reduction in occipital-parietal alpha-band power was observed similar to changes expected for visual stimuli. No evidence for aversive generalization to the tone most similar to the CS+ was observed in terms of alpha-band power changes, aversiveness ratings, or pupil dilation. By-trial analyses found that selective alpha-band changes continued to increase as aversive conditioning continued, beyond when participants reported awareness of the contingencies. The results support a theoretical model in which selective alpha power represents a cross-modal index of continuous aversive learning, accompanied by sustained sensory discrimination of conditioned threat from safety cues.

Stress-induced Changes in Autonomic Reactivity Vary with Adolescent Violence Exposure and Resting-state Functional Connectivity

Exposure to violence during childhood can lead to functional changes in brain regions that are important for emotion expression and regulation, which may increase susceptibility to internalizing disorders in adulthood. Specifically, childhood violence exposure can disrupt the functional connectivity among brain regions that include the prefrontal cortex (PFC), hippocampus, and amygdala. Together, these regions are important for modulating autonomic responses to stress. However, it is unclear to what extent changes in brain connectivity relate to autonomic stress reactivity and how the relationship between brain connectivity and autonomic responses to stress varies with childhood violence exposure. Thus, the present study examined whether stress-induced changes in autonomic responses (e.g., heart rate, skin conductance level (SCL)) varied with amygdala-, hippocampus-, and ventromedial prefrontal cortex (vmPFC)-whole brain resting-state functional connectivity (rsFC) as a function of violence exposure. Two hundred and ninety-seven participants completed two resting-state functional magnetic resonance imaging scans prior to (pre-stress) and after (post-stress) a psychosocial stress task. Heart rate and SCL were recorded during each scan. Post-stress heart rate varied negatively with post-stress amygdala-inferior parietal lobule rsFC and positively with post-stress hippocampus-anterior cingulate cortex rsFC among those exposed to high, but not low, levels of violence. Results from the present study suggest that post-stress fronto-limbic and parieto-limbic rsFC modulates heart rate and may underlie differences in the stress response among those exposed to high levels of violence.

Age‐related changes in autonomic response: A pupillary light reflex and heart rate variability study

AbstractBackgroundAutonomic nervous system (ANS) dysfunction has been implicated with cardiovascular diseases, sudden‐cardiac‐death, and aging. The pupillary light reflex (PLR) and heart rate variability (HRV) are noninvasive tools of autonomic evaluation. However, the former remains underutilized in clinical practice.PurposeWe investigated the relationship between PLR, HRV, and aging to determine the normal distribution of age‐adjusted PLR and HRV measurements and to determine which method is best correlated with age.MethodsHealthy participants aged 18–65 years were recruited. Following a dark adaptation period, pupillary reactivity parameters were collected using an automated, commercial pupillometer. HRV measurements were derived using a high‐resolution electrocardiogram. Correlations of PLR and HRV parameters to age were computed using linear‐regression analysis.ResultsA total of 111 healthy participants were included. Older age was correlated with lower maximum and minimum pupillary diameters following dark adaptation and illumination (R = −0.51, p < 0.001 and R = −0.47, p < 0.001, respectively). Average constriction and dilatation velocity were correlated with age (R = 0.33, p < 0.001 and R = −0.21, p = 0.025, respectively). HRV parameters were also associated inversely with age (SDNN; R = −0.31, p < 0.001 and RMSSD; R = −0.33, p < 0.001). Other parameters showed lower significance levels.ConclusionPupillary light reflex measurements demonstrated stronger age correlation than short‐term HRV time‐domain indices. Due to its merit in depicting normal age‐related ANS changes, PLR can be utilized to differentiate between pathological and physiological deviations from age‐adjusted norms, seemingly better than HRV. Further research is warranted on incorporating PLR‐based ANS dysfunction evaluation and monitoring the increasingly aging population.

Heart Rate Variability and Gastric Electrical Response to a Cold Pressor Task in Youth with Functional Dyspepsia.

While stress has been implicated in functional dyspepsia (FD), the mechanisms by which stress results in symptoms are not well defined. The aim of the current study was to assess gastric myoelectric and autonomic changes in response to a physical stressor in youth with FD. In a group of healthy controls and pediatric FD subjects, we recorded ECG and EGG signals 30min before and 60min after, a cold pressor task (CPT). Gastric EGG and heart rate variability (HRV) parameters were calculated in pre- and post-CPT stages and in short intervals. The pre-CPT percent tachygastria was higher in FD subjects as compared to controls. However, CPT did not induce any EGG changes in either controls or FD subjects and the two groups did not differ from each other post-CPT. The CPT resulted in an increase in HRV and standard deviation of NN intervals in controls; there was no change in any HRV parameter in FD subjects. Acute physical stress does not appear to induce gastric electrical abnormalities in youth with FD. Youth with FD appear to lack the normal flexible autonomic response to a physical stressor.

Influences of environmental stressors on autonomic function in 12-month-old infants: understanding early common pathways to atypical emotion regulation and cognitive performance.

Previous research has suggested that children exposed to more early-life stress show worse mental health outcomes and impaired cognitive performance in later life, but the mechanisms subserving these relationships remain poorly understood. Using miniaturised microphones and physiological arousal monitors (electrocardiography, heart rate variability and actigraphy), we examined for the first time infants' autonomic reactions to environmental stressors (noise) in the home environment, in a sample of 82 12-month-old infants from mixed demographic backgrounds. The same infants also attended a laboratory testing battery where attention- and emotion-eliciting stimuli were presented. We examined how children's environmental noise exposure levels at home related to their autonomic reactivity and to their behavioural performance in the laboratory. Individual differences in total noise exposure were independent of other socioeconomic and parenting variables. Children exposed to higher and more rapidly fluctuating environmental noise showed more unstable autonomic arousal patterns overall in home settings. In the laboratory testing battery, this group showed morelabile andshort-lived autonomic changes in response to novel attention-eliciting stimuli, along with reduced visual sustained attention. They also showed increased arousal lability in response to an emotional stressor. Our results offer new insights into the mechanisms by which environmental noise exposure may confer increased risk of adverse mental health and impaired cognitive performance during later life.

Effects of Ketamine on Pupillary Reflex Dilation: A Case Report.

Ketamine is an important component of multimodal treatment and a commonly used anesthetic drug. However, its analgesic effects have not been fully assessed intraoperatively because of difficulties in measuring this effect. In this case report, a woman underwent general anesthesia with ketamine and its pupillary reflexes were measured to detect autonomic changes in response to pain. With increasing doses of ketamine, the pupillary light reflex and the pupillary dilation response decreased. This could be caused by N-methyl-D-aspartate receptor antagonism in the pupillary reflexes pathway or by the analgesic effects of ketamine.

CBView: Merging Data in Metabolic Diagnosis

The metabolic syndrome is a set of risk factors associated with increased cardiovascular risk. These changes to the standard metabolic functions are associated with increased blood insulin and with insulin resistance, which is the common feature of disease pathophysiology. Although with admissible genetic inheritance, the metabolic syndrome symptoms increase with age, sedentarism, weight gain, tobacco, and poor dietetic habits.Due to their characteristics, clinical manifestations of metabolic diseases are perceived by the patient at advanced stages of metabolic dysfunction, when the risk of an acute cardiovascular event is high. Early detection of disturbed glucose homeostatic mechanisms, by recording efferent responses to stimuli like meal ingestion, is, therefore, a methodology with diagnostic potential acting as a predictive measure of metabolic dysfunction.This work presents a novel software (CBView) that analyses the records of physiological responses mediated by the carotid bodies to provocation tests, obtained by a new medical device (CBMeter) aiming to the early tracking of changes in autonomic responses that control metabolism, and thus providing quantitative metrics to assess metabolic dysfunction.

Is heart rate variability affected by distinct motor imagery strategies?

Although some studies have reported significant changes in autonomic responses according to the perspective-taking during motor imagery [first person perspective (1P) and third person perspective (3P)], investigations on how the strategies adopted to mentally simulate a given movement affect the heart rate variability (HRV) seem so far unexplored. Twenty healthy subjects mentally simulated the movement of middle-finger extension in 1P and 3P, while electrocardiogram was recorded. After each task, the level of easiness was self-reported. Motor imagery ability was also assessed through the revised version of Movement Imagery Questionnaire (MIQ-R) and a mental chronometry index. The traditional measures of HRV in the time- and frequency-domain were compared between 1P and 3P tasks by using Student's t-test for dependent samples. The MIQ-R results showed that subjects had the same facility to imagine movements in 1P or 3P. The mental chronometry index revealed a similar temporal course only between 1P and execution, while the 3P strategy had a shorter duration. Additionally, the subjective report was similar between the experimental tasks. Regarding the HRV measures, the low frequency component, in log-transformed unit, was significantly higher (p=0.017) in 1P than 3P, suggesting a higher activity of the sympathetic system during 1P. This log-transformed HRV parameter seems to be more sensitive than normalized values for the assessment of the motor imagery ability, together with questionnaires, scales and mental chronometry.

Developmental changes in autonomic responses are associated with future reward/punishment expectations: A study of sympathetic skin responses in the Markov decision task

ObjectiveAutonomic nervous system activity is recognized as a major component of emotional responses. Future reward/punishment expectations depend upon the process of decision making in the frontal lobe, which is considered to play an important role in executive function. The aim of this study was to investigate the relationship between autonomic responses and decision making during reinforcement tasks using sympathetic skin responses (SSR). MethodsNine adult and 9 juvenile (mean age, 10.2years) volunteers were enrolled in this study. SSRs were measured during the Markov decision task (MDT), which is a reinforcement task. In this task, subjects must endure a small immediate loss to ultimately get a large reward. The subjects had to undergo three sets of tests and their scores in these tests were assessed and evaluated. ResultsAll adults showed gradually increasing scores for the MDT from the first to third set. As the trial progressed from the first to second set in adults, SSR appearance ratios remarkably increased for both punishment and reward expectations. In comparison with adults, children showed decreasing scores from the first to second set. There were no significant inter-target differences in the SSR appearance ratio in the first and second set in children. In the third set, the SSR appearance ratio for reward expectations was higher than that in the neutral condition. ConclusionsIn reinforcement tasks, such as MDT, autonomic responses play an important role in decision making. We assume that SSRs are elicited during efficient decision making tasks associated with future reward/punishment expectations, which demonstrates the importance of autonomic function. In contrast, in children around the age of 10years, the autonomic system does not react as an organized response specific to reward/punishment expectations. This suggests the immaturity of the future reward/punishment expectations process in children.

Differences in autonomic functions as related to induced stress between children with and without cerebral palsy while performing a virtual meal-making task

BackgroundEfforts to improve the participation and performance of children with cerebral palsy (CP) are often related to the adaptation of environmental conditions to meet their cognitive and motor abilities. However, the influence of affective stimuli within the environment on emotion and performance, and their ability to improve or impede the children's participation has not been investigated in any systematic way although the emerging evidence suggests that it affects the individuals in many levels. Objectives(1) To measure autonomic responses to affective stimuli during a simulated Meal-Maker task in children with CP in comparison to children who are typically developing, and (2) to examine the interactions between autonomic functions, subjective reports of stress, and task performance among children with and without CP. MethodsFifteen children with CP and 19 typically developing peers (6 to 12 years) participated. After completing behavioral questionnaires (e.g., State and Trait Anxiety Inventories), children prepared meals within a camera tracking virtual Meal-Maker environment. Either a negative, positive, or neutral visual stimulus was displayed, selected from the International Affective Picture System. Children also passively viewed the same pictures while rating their valence and arousal levels. Heart rate (HR) and skin conductance were recorded synchronously with stimulus onset. ResultsSignificant differences in autonomic functions were found between groups, i.e., a higher “low frequency” to “high frequency” (LF:HF) ratio in the children with CP during the meals associated with a negative stimulus (p=0.011). Only children with CP had significant positive correlations between trait anxiety and LF:HF ratio during virtual meal-making associated with positive (p=0.049) and negative stimuli (p=0.003) but not during neutral stimuli. For children with CP the amplitude of skin conductance response during passive picture viewing was significantly higher for negative than for positive stimuli (p=0.017) but there were no significant changes in autonomic responses during virtual Meal-Maker task.Significant correlations between trait anxiety, autonomic activity during the calm state and Meal-Maker performance outcomes were found only for children with CP. ConclusionsIn general, the Meal-Maker virtual environment was shown to be a feasible platform for the investigation of the effect of emotionally loaded stimuli on the balance of autonomic functions in children with and without CP. Anxiety level appears to play a significant role in children with CP and should be considered as a potentially important factor during clinical evaluation and intervention. Further studies are needed to develop additional measurements of emotional responses and to refine the types of affective interference.

How the several dimention of interoception affect the changes in autonomic response?

How the several dimention of interoception affect the changes in autonomic response?

Anger in brain and body: the neural and physiological perturbation of decision-making by emotion.

Emotion and cognition are dynamically coupled to bodily arousal: the induction of anger, even unconsciously, can reprioritise neural and physiological resources toward action states that bias cognitive processes. Here we examine behavioural, neural and bodily effects of covert anger processing and its influence on cognition, indexed by lexical decision-making. While recording beat-to-beat blood pressure, the words ANGER or RELAX were presented subliminally just prior to rapid word/non-word reaction-time judgements of letter-strings. Subliminal ANGER primes delayed the time taken to reach rapid lexical decisions, relative to RELAX primes. However, individuals with high trait anger were speeded up by subliminal anger primes. ANGER primes increased systolic blood pressure and the magnitude of this increase predicted reaction time prolongation. Within the brain, ANGER trials evoked an enhancement of activity within dorsal pons and an attenuation of activity within visual occipitotemporal and attentional parietal cortices. Activity within periaqueductal grey matter, occipital and parietal regions increased linearly with evoked blood pressure changes, indicating neural substrates through which covert anger impairs semantic decisions, putatively through its expression as visceral arousal. The behavioural and physiological impact of anger states compromises the efficiency of cognitive processing through action-ready changes in autonomic response that skew regional neural activity.

The Other in Me: Interpersonal Multisensory Stimulation Changes the Mental Representation of the Self

BackgroundRecent studies have shown that the well-known effect of multisensory stimulation on body-awareness can be extended to self-recognition. Seeing someone else’s face being touched at the same time as one’s own face elicits changes in the mental representation of the self-face. We sought to further elucidate the underlying mechanisms and the effects of interpersonal multisensory stimulation (IMS) on the mental representation of the self and others.Methodology/Principal FindingsParticipants saw an unfamiliar face being touched synchronously or asynchronously with their own face, as if they were looking in the mirror. Following synchronous, but not asynchronous, IMS, participants assimilated features of the other’s face in the mental representation of their own face as evidenced by the change in the point of subjective equality for morphed pictures of the two faces. Interestingly, synchronous IMS resulted in a unidirectional change in the self-other distinction, affecting recognition of one’s own face, but not recognition of the other’s face. The participants’ autonomic responses to objects approaching the other’s face were higher following synchronous than asynchronous IMS, but this increase was not specific to the pattern of IMS in interaction with the viewed object. Finally, synchronous, as compared to asynchronous, IMS resulted in significant differences in participants’ ratings of their experience, but unlike other bodily illusions, positive changes in subjective experience were related to the perceived physical similarity between the two faces, and not to identification.Conclusions/SignificanceSynchronous IMS produces quantifiable changes in the mental representations of one’s face, as measured behaviorally. Changes in autonomic responses and in the subjective experience of self-identification were broadly consistent with patterns observed in other bodily illusions, but less robust. Overall, shared multisensory experiences between self and other can change the mental representation of one’s identity, and the perceived similarity of others relative to one’s self.

Electrooculogram based study to assess the effects of prolonged eye fixation on autonomic responses and its possible implication in man-machine interface

Need of an alternative method for communication has been seriously felt for man-machine interface (MMI) because of difficulties in the analysis of complex electroencephalogram (EEG). The proposed method analyses the alterations in autonomic responses due to prolonged eye gaze. The experimental paradigm was designed to include 20 trials of 30 s for eye gaze and 10 s for relaxation. Along with electrooculogram (EOG), electrocardiogram (ECG), pulse plethysmogram (PPG) and electrodermal activity (EDA) was recorded from the five male subjects. Results demonstrated that the eye gaze modulates heart rate, pulse rate and EDA signals that were too analyzed to occur with the latency of nearly 5 s, which is nearer to the EEG based brain-machine interfaces (BMI). The alterations in autonomic variables persist for longer duration and the maximum change in pulse rate was observed at 26.79 s (5.16 beats/minute) in comparison to the maximum change of heart rate (6.27 beats/minute) at 27.45 s, respectively. Further, the changes in EDA were found more at the onset of events. With the above findings, it can be suggested that the changes in autonomic responses with the mental effort produced by eye gaze were distinct and provides a good platform for the development of MMI.

Autonomic dysfunction and risk factors associated with Trypanosoma cruzi infection among children in Arequipa, Peru.

Chagas disease affects an estimated 8 million people in Latin America. Infected individuals have 20-30% lifetime risk of developing cardiomyopathy, but more subtle changes in autonomic responses may be more frequent. We conducted a matched case-control study of children in Arequipa, Peru, where triatomine infestation and Trypanosoma cruzi infection are emerging problems. We collected data on home environment, history, physical examination, electrocardiogram, and autonomic testing. Signs of triatomine infestation and/or animals sleeping in the child's room and household members with Chagas disease were associated with increased infection risk. Electrocardiogram findings did not differ between cases and controls. However, compared with control children, infected children had blunted autonomic responses by three different measures, the Valsalva maneuver, the cold pressor test, and the orthostatic test. T. cruzi-infected children show autonomic dysfunction, although the prognostic value of this finding is not clear. Sustained vector control programs are essential to decreasing future T. cruzi infections.

Autonomic responses to pain in aging and dementia

Increasing age and dementia are accompanied by an increased risk for undertreatment of pain owing to difficulty in assessing pain. Registration of autonomic responses to pain may contribute to a more reliable pain assessment. The aim of this review was to gain more insight into autonomic responses to pain in older persons with and without dementia. Literature searches were performed in the online databases MEDLINE and Web of Science. Seven studies on autonomic responses to pain in older people with or without dementia were included in the review. Autonomic responses to pain are present in older people with and without dementia, although they may be attenuated. Because no distinction could be made between different dementia subtypes based on these studies, predictions of changes in autonomic responses to pain have been made based on neuropathological changes. It can be concluded that autonomic responses to pain are attenuated in older people with and without dementia. Studies to specify the changes in the different autonomic responses for the different dementia subtypes are needed.

A Virtual Meal-Making Environment as a Platform to Measure the Effect of Affective Stimuli on Emotional Response and Task Performance in Children with and without Cerebral Palsy

The study examined whether a functional virtual environment (VE) may be used to provide affective stimuli (AS) that lead to changes in the emotional responses and task performance of children with and without cerebral palsy (CP). Fifteen children with CP and 19 typically developing (TD) peers (6 to 12 years) prepared seven virtual meals in a predefined order within the Emotional Meal-Maker (EMM), a virtual meal-making VE, run on a 2D video capture VR platform. Six meals included either a negative, positive, or neutral visual stimuli, selected from the International Affective Picture System (IAPS). Heart rate (HR) and skin conductance were recorded online, synchronized with stimulus onset. Significant differences were found between groups in task performance and heart rate variability (HRV) components, e.g., higher low frequency (LF)/ high frequency (HF) ratio in CP during the EMM task (U=2517.5, p<001), regardless of type of AS. No significant changes in autonomic responses as a function of AS were found. The implications of these results are discussed.

S12.4 Right middle cerebral artery stroke dampens cardiovascular responses to music, left middle cerebral artery stroke decreases blood pressure response to pleasant music

After ischemic stroke, there may be hemisphere-specific dysfunction of autonomic modulation. Processing of music is also hemisphere-specific and valence-dependent [1]. We hypothesize that patients who experienced a stroke in the middle cerebral artery territory have hemisphere- and valence-dependent changes in autonomic responses to music.

A neuroanatomical dissociation for emotion induced by music

Does feeling an emotion require changes in autonomic responses, as William James proposed? Can feelings and autonomic responses be dissociated? Findings from cognitive neuroscience have identified brain structures that subserve feelings and autonomic response, including those induced by emotional music. In the study reported here, we explored whether feelings and autonomic responses can be dissociated by using music, a stimulus that has a strong capacity to induce emotional experiences. We tested two brain regions predicted to be differentially involved in autonomic responsivity (the ventromedial prefrontal cortex) and feeling (the right somatosensory cortex). Patients with damage to the ventromedial prefrontal cortex were impaired in their ability to generate skin-conductance responses to music, but generated normal judgments of their subjective feelings in response to music. Conversely, patients with damage to the right somatosensory cortex were impaired in their self-rated feelings in response to music, but generated normal skin-conductance responses to music. Control tasks suggested that neither impairment was due to basic defects in hearing the music or in cognitively recognizing the intended emotion of the music. The findings provide evidence for a double dissociation between feeling emotions and autonomic responses to emotions, in response to music stimuli.

Heart Rate Turbulence and Heart Rate Variability in Patients with Atrial Synchronous Ventricular Pacing

Heart rate turbulence (HRT) and heart rate variability (HRV) have been shown to be independent and powerful predictors of mortality in a specific group of cardiac patients. Pacing has unfavorable effects on autonomic function. Our aim is to investigate autonomic responses to atrial synchronous ventricular pacing (VDD) by evaluating HRT and HRV parameters. The study groups comprised 12 control and 12 patients without organic heart disease and with normal sinus function who were implanted with a permanent VDD pacing system for high-degree atrioventricular block. The HRV and HRT analysis were assessed from a 24-hour Holter recording. There was no statistically significant difference between the two groups for HRV parameters. When HRT parameters were compared, turbulence onset was significantly higher in the cardiac paced group than the controls group (2.729 +/- 8.818 vs -1.565 +/- 8.301, P = 0.006), but no statistically significant difference was found between the two groups for turbulence slope (11.166 +/- 10.034 vs 31.675 +/- 28.107, P = 0.68). The number of patients who had abnormal HRT onset was significantly higher in the paced group than controls (9 vs 2, P = 0.004). Atrial synchronous pacing has unfavorable effects on autonomic function. Altered ventricular depolarization sequence may lead to changes in autonomic response. Although we found no difference in HRV parameters between the control and VDD patient groups, the HRT onset and number of patients with abnormal HRT onset was significantly higher in VDD patients. HRT onset can be a better way of noninvasive autonomic response predictor in VDD patients.