Alterations in electrodermal activity and cardiac parasympathetic tone during hypnosis

Exploring autonomic nervous system (ANS) changes during hypnosis is critical for understanding the nature and extent of the hypnotic phenomenon and for identifying the mechanisms underlying the effects of hypnosis in different medical conditions. To assess ANS changes during hypnosis, electrodermal activity and pulse rate variability (PRV) were measured in 121 young adults. Participants either received hypnotic induction (hypnosis condition) or listened to music (control condition), and both groups were exposed to test suggestions. Blocks of silence and experimental sound stimuli were presented at baseline, after induction, and after de-induction. Skin conductance level (SCL) and high frequency (HF) power of PRV measured at each phase were compared between groups. Hypnosis decreased SCL compared to the control condition; however, there were no group differences in HF power. Furthermore, hypnotic suggestibility did not moderate ANS changes in the hypnosis group. These findings indicate that hypnosis reduces tonic sympathetic nervous system activity, which might explain why hypnosis is effective in the treatment of disorders with strong sympathetic nervous system involvement, such as rheumatoid arthritis, hot flashes, hypertension, and chronic pain. Further studies with different control conditions are required to examine the specificity of the sympathetic effects of hypnosis

Muscle fatigue assessment through electrodermal activity analysis during isometric contraction

We studied the effects of muscle fatigue on the Autonomic Nervous System (ANS) dynamics. Specifically, we monitored the electrodermal activity (EDA) on 32 healthy subjects performing isometric biceps contraction. As assessed by means of an electromyography (EMG) analysis, 15 subjects showed muscle fatigue and 17 did not. EDA signals were analyzed using the recently proposed cvxEDA model in order to decompose them into their phasic and tonic components and extract effective features to study ANS dynamics. A statistical comparison between the two groups of subjects was performed. Results revealed that relevant phasic EDA features significantly increased in the fatigued group. Moreover, a pattern recognition system was applied to the EDA dataset in order to automatically discriminate between fatigued and non-fatigued subjects. The proposed leave-one-subject-out KNN classifier showed an accuracy of 75.69%. These results suggest the use of EDA as correlate of muscle fatigue, providing integrative information to the standard indices extracted from the EMG signals

Autonoumous Nervous System biosignal processing via EDA and HRV from a wearable device

The assessment of changes in the autonomous nervous system (ANS) with certain diseases and pathologies conditions, has been demonstrated to have important prognostic and diagnostic value, so delineating the role of autonomous activity is important to prevent health diseases. There are many approaches to directly measure the sympathetic and parasympathetic nervous system, although, most of themare invasive and unable to provide continuous monitoring, leading to inaccurate assessment of the autonomous nervous system. Heart rate variability (HRV) and Electrodermal activity (EDA) are presented has noninvasive methods to assess the ANS, by computing the spectral analysis of both HRV and EDA biosignals. The combination of these signals is necessary to correctly measure the activity of the sympathetic and parasympathetic system, due to the fact that frequency analysis of HRV only provides the level of unbalance between these two systems, while EDA reflects only activity from the sympathetic system. ANS biosignal processing via HRV and EDA from a wearable device was studied in this thesis, in order to provide continuous monitoring. A wearable device is the ideal solution, as HRV can be calculated with photoplethysmography signals from the wrist and EDA from the fingers, providing wireless and continuous monitoring of the subjects. The extraction of the HRV and EDA features, that describe the activity of the sympathetic and parasympathetic system, were obtained by submitting the subjects to a mental arithmetic stress test, and then compared to the baseline values, in order to verify changes in the autonomous nervous system between the two situations. The distinct response to stress for the subjects was then predicted usingmachine-learning classification mechanisms, with the ability to predict how the subject will respond when submitted to a situation of stress, using only time-domain features, instead of frequency-domain features, which reduces the time needed to performthe classification

Sex differences in emotional concordance.

Emotions involve response synchronization across experiential, physiological, and behavioral systems, referred to as concordance or coherence. Women are thought to be more emotionally aware and expressive than men and may therefore display stronger response concordance; however, research on this topic is scant. Using a random-order film-average design, we assessed concordance among experiential (arousal, valence), autonomic (electrodermal activity, heart rate, preejection period, respiratory sinus arrhythmia), respiratory (respiratory rate), and behavioral (corrugator and zygomatic electromyography) responses to 15 two-minute films varying in valence and arousal. We then calculated for each participant and pair of measures a within-subject correlation index using averages from the 15 films. Pronounced individual concordance of up to 0.9 was observed. Arousal-physiology and valence-behavior concordances were particularly pronounced. Women displayed higher concordance than men for almost all pairs of measures. Findings indicate stronger psychophysiological response coupling in women than men and provide novel insights into affective differences between the sexes

Electrodermal Activity as an Indicator of Sensory Processing in Typically Developing Children and Children with Autism Spectrum Disorders

Objective: The purpose of this study was to test the reliability of the Sensory Challenge Protocol (SCP), a laboratory procedural tool that has been used to discriminate differences in sensory processing between typically developing (TD) children and children with Autism Spectrum Disorder (ASD). Method: Electrodermal activity (EDA) during rest and in response to sensation was measured using skin conductance. Skin conductance measures were used to calculate ICC (Intraclass Correlation Coefficient) reliability in 14 children with ASD and 18 TD children. Results: ICC reliability during rest phase (tonic) for both groups was good to moderate (.65 - .73). ICC reliability during response to sensation (phasic) was good to moderate for amplitude (.60 - .81) and magnitude (.50 - .75) of response measures. In addition, high to moderate reliability (.51 - .93) for Non-specific response (NSR) measures were found. Conclusion: This study supports the SCP as a reliable tool to measure response to sensation in TD children and children with ASD

The effects of music and auditory stimulation on autonomic arousal, cognition and attention : A systematic review

Peer reviewe

Prerequisites for Affective Signal Processing (ASP)

Although emotions are embraced by science, their recognition has not reached a satisfying level. Through a concise overview of affect, its signals, features, and classification methods, we provide understanding for the problems encountered. Next, we identify the prerequisites for successful Affective Signal Processing: validation (e.g., mapping of constructs on signals), triangulation, a physiology-driven approach, and contributions of the signal processing community. Using these directives, a critical analysis of a real-world case is provided. This illustrates that the prerequisites can become a valuable guide for Affective Signal Processing (ASP)

Parasympathetic functions in children with sensory processing disorder.

The overall goal of this study was to determine if parasympathetic nervous system (PsNS) activity is a significant biomarker of sensory processing difficulties in children. Several studies have demonstrated that PsNS activity is an important regulator of reactivity in children, and thus, it is of interest to study whether PsNS activity is related to sensory reactivity in children who have a type of condition associated with sensory processing disorders termed sensory modulation dysfunction (SMD). If so, this will have important implications for understanding the mechanisms underlying sensory processing problems of children and for developing intervention strategies to address them. The primary aims of this project were: (1) to evaluate PsNS activity in children with SMD compared to typically developing (TYP) children, and (2) to determine if PsNS activity is a significant predictor of sensory behaviors and adaptive functions among children with SMD. We examine PsNS activity during the Sensory Challenge Protocol; which includes baseline, the administration of eight sequential stimuli in five sensory domains, recovery, and also evaluate response to a prolonged auditory stimulus. As a secondary aim we examined whether subgroups of children with specific physiological and behavioral sensory reactivity profiles can be identified. Results indicate that as a total group the children with severe SMD demonstrated a trend for low baseline PsNS activity, compared to TYP children, suggesting this may be a biomarker for SMD. In addition, children with SMD as a total group demonstrated significantly poorer adaptive behavior in the communication and daily living subdomains and in the overall Adaptive Behavior Composite of the Vineland than TYP children. Using latent class analysis, the subjects were grouped by severity and the severe SMD group had significantly lower PsNS activity at baseline, tones and prolonged auditory. These results provide preliminary evidence that children who demonstrate severe SMD may have physiological activity that is different from children without SMD, and that these physiological and behavioral manifestations of SMD may affect a child\u27s ability to engage in everyday social, communication, and daily living skills

Emotional intelligence buffers the effect of physiological arousal on dishonesty

We studied the emotional processes that allow people to balance two competing desires: benefitting from dishonesty and keeping a positive self-image. We recorded physiological arousal (skin conductance and heart rate) during a computer card game in which participants could cheat and fail to report a certain card when presented on the screen to avoid losing their money. We found that higher skin conductance corresponded to lower cheating rates. Importantly, emotional intelligence regulated this effect; participants with high emotional intelligence were less affected by their physiological reactions than those with low emotional intelligence. As a result, they were more likely to profit from dishonesty. However, no interaction emerged between heart rate and emotional intelligence. We suggest that the ability to manage and control emotions can allow people to overcome the tension between doing right or wrong and license them to bend the rules