Bilateral electrodermal activity: relationships to state and trait characteristics of hemisphere asymmetry

Into the Wild: The Challenges of Physiological Stress Detection in Laboratory and Ambulatory Settings

Stress and mental health have become major concerns worldwide. Research has already extensively investigated physiological signals as quantitative and continuous markers of stress. In recent years, the focus of the field has shifted from the laboratory to the ambulatory environment. We provide an overview of physiological stress detection in laboratory settings with a focus on identifying physiological sensing priorities, including electrocardiogram, skin conductance, and electromyogram, and the most suitable machine learning techniques, of which the choice depends on the context of the application. Additionally, an overview is given of new challenges ahead to move toward the ambulant environment, including the influence of physical activity, lower signal quality due to motion artifacts, the lack of a stress reference, and the subject-dependent nature of the physiological stress response. Finally, several recommendations for future research are listed, focusing on large-scale, longitudinal trials across different population groups and just-in-time interventions to move toward disease prevention and interception.

Emotion Regulation in Borderline Personality Disorder: An Experimental Investigation of the Effects of Instructed Acceptance and Suppression

Difficulties with emotion regulation are central to borderline personality disorder (BPD). Recent research suggests that avoidance of emotions in general, and emotion suppression specifically, may be commonly used among those who meet criteria for the disorder. Contemporary behavioral interventions for BPD incorporate cognitive and behavioral skills to increase emotional experiencing and acceptance while decreasing behaviors that function to escape or avoid from emotions. Few studies, however, have experimentally examined the effects of instructed emotion suppression and acceptance in BPD. The present study examined the effects of instructed use of different emotion regulation strategies on emotions, psychophysiology, and behavior in BPD. Participants with BPD, major depressive disorder (MDD), and nonpsychiatric controls (N = 193) were randomly assigned to either suppress or accept emotions during an audio recording of a social rejection scenario, and completed a behavioral measure of distress tolerance. BPD participants exhibited greater heart rate variability in the acceptance (vs. suppression) condition; this pattern was not evident within the other groups. These results suggest that deliberate use of acceptance-based emotion regulation strategies may have unique physiological effects among individuals with BPD.

Real-time mobile detection of drug use with wearable biosensors: a pilot study

While reliable detection of illicit drug use is paramount to the field of addiction, current methods involving self-report and urine drug screens have substantial limitations that hinder their utility. Wearable biosensors may fill a void by providing valuable objective data regarding the timing and contexts of drug use. This is a preliminary observational study of four emergency department patients receiving parenteral opioids and one individual using cocaine in a natural environment. A portable biosensor was placed on the inner wrist of each subject, to continuously measure electrodermal activity (EDA), skin temperature, and acceleration. Data were continuously recorded for at least 5 min prior to drug administration, during administration, and for at least 30 min afterward. Overall trends in biophysiometric parameters were assessed. Injection of opioids and cocaine use were associated with rises in EDA. Cocaine injection was also associated with a decrease in skin temperature. Opioid tolerance appeared to be associated with a blunted physiologic response as measured by the biosensor. Laterality may be an important factor, as magnitude of response varied between dominant and nondominant wrists in a single patient with bilateral wrist measurements. Changes in EDA and skin temperature are temporally associated with intravenous administration of opioids and cocaine; the intensity of response, however, may vary depending on history and extent of prior use.

Stress-induced alterations of left-right electrodermal activity coupling indexed by pointwise transinformation

In this study, we tested the hypothesis that experimental stress induces a specific change of left-right electrodermal activity (EDA) coupling pattern, as indexed by pointwise transinformation (PTI). Further, we hypothesized that this change is associated with scores on psychometric measures of the chronic stress-related psychopathology. Ninety-nine university students underwent bilateral measurement of EDA during rest and stress-inducing Stroop test and completed a battery of self-report measures of chronic stress-related psychopathology. A significant decrease in the mean PTI value was the prevalent response to the stress conditions. No association between chronic stress and PTI was found. Raw scores of psychometric measures of stress-related psychopathology had no effect on either the resting levels of PTI or the amount of stress-induced PTI change. In summary, acute stress alters the level of coupling pattern of cortico-autonomic influences on the left and right sympathetic pathways to the palmar sweat glands. Different results obtained using the PTI, EDA laterality coefficient, and skin conductance level also show that the PTI algorithm represents a new analytical approach to EDA asymmetry description.

Sensors and Sensor Systems for Psychophysiological Monitoring

Abstract. There are a wide range of sensors for acquiring signals from the human body in noninvasive ways. Some of those in use date back a few decades, and many new technologies have enabled different sensors designs in recent years. This review covers the following classes of sensors: electric, magnetic, electrochemical, mechanical, thermal, and optical. Sensor systems that are portable, safe, and low-cost are now becoming possible. This review provides an overview focussing on the technology behind sensors currently used by psychophysiologists with the objective of illuminating the choices available for acquiring signals that inform us about cognitive processes, emotional states, and behavioural patterns. In previously published encyclopaedic-type reviews of psychophysiology, the focus has been on what is measured, not how it is measured. By focussing on how the sensors and sensor systems work, this review aims to provide users of these technologies with information that will help them decide on the appropriate sensor to use, as well as to facilitate innovation and development of new sensors.

Lateralization in human nasal chemoreception: differences in bilateral electrodermal responses related to olfactory and trigeminal stimuli

The study of olfactory lateralization in humans has given rise to many publications, but the findings have often been contradictory. There is growing evidence to suggest that the nature of the olfactory stimulus influences the processes of lateralization. An important factor could be the trigeminal component. Indeed, most odorants simultaneously stimulate both olfactory (CN I) and trigeminal (CN V) systems which differ in terms of their central projections, ipsilaterally for CN I and contralaterally for CN V. The aim of this study was to investigate variations in psychophysiological measurements between a nasal input with low (phenyl ethyl alcohol (PEA)) and high (allyl isothiocyanate (AIC)) intranal trigeminal stimulation. In a first experiment (20 subjects), the intensity, hedonicity and irritation levels of stimulus were tested with a psychophysical evaluation to study the possible influences of perceptual characteristics. A second experiment (37 subjects) used bilateral electrodermal recordings and compared the skin conductance responses (SCRs) for both nasal inputs on either monorhinal and birhinal stimulations. Firstly, the electrodermal activity (EDA) results showed no differences between the two nostrils for PEA as well as AIC, but differences in relation to the type of stimulus, e.g. higher amplitude in response to AIC versus PEA. Secondly, the results indicated bilateral differences in EDA recordings related to the nature of the stimulus and are discussed in terms of hemispheric asymmetric activation.

Dissociated autonomic regulation during stress and physical complaints

OBJECTIVE

In order to evaluate the relevance of individual differences in the regulation of autonomic subsystems to psychosomatic processes, reactivity of the autonomic nervous system to an emotional stressor was related to the occurrence of physical complaints. In contrast to most other studies, the measures were related to the degree of actually experienced stress.

METHODS

In a large sample (n=111), electrodermal activity (EDA) and heart rate variability (HRV) were obtained at rest and during emotional stress. Physical complaints were assessed by a standardized symptom checklist providing subscales for different physiological systems.

RESULTS

Subjects who were actually stressed by the stress induction procedure but showed only weak reactivity of EDA, and subjects who were only slightly stressed but showed a marked EDA response reported a high amount of gastrointestinal complaints. A greater decrease of high-frequency HRV from the rest to the stress condition was associated with reports of relatively more cardiovascular complaints.

CONCLUSION

Findings indicate that the link between regulation of EDA and gastrointestinal functions has to be localized in higher brain structures and support the hypothesis that minor autonomic dysregulation may represent one pathway linking negative affect and the development of physical disorders.

Quality of odor and olfactory lateralization processes in humans

The study of olfactory lateralization processes in humans has given rise to many publications, but the resulting data have not been homogeneous. Sensorial cerebral asymmetry depends on several factors (nature of task, characteristics of subjects, etc.) and could also depend on the quality of the stimulus, especially in olfaction. This field appears to be widely unexplored and the quality of odor is a complex property. The aim of this study was to investigate variations in psychophysiological measurements (bilateral electrodermal recordings) related to the quality of odors. Electrodermal asymmetries were used as a function of differential hemispheric activation. Two major characteristics of odor were explored, the hedonic valence (pleasant/unpleasant) and the trigeminal component (irritant/non-irritant). The results obtained in a sample of 30 right-handed subjects (15 males and 15 females) showed a predominance of the right hemisphere in the treatment of olfactory information not depending on the quality of odor, except the trigeminal-nerve activation.

Associations between EEG asymmetries and electrodermal lability in low vs. high depressive and anxious normal individuals

In order to investigate one aspect of cortical-autonomic control, cortical activation asymmetries, measured by EEG, were related to activity of the sympathetic nervous system, measured by EDA (electrodermal lability, number of spontaneous fluctuations), in two large samples. Since it may help to explain the participation of psychological factors in the development of various somatic complaints and disorders, we examined whether inter-individual differences in autonomic nervous system regulation may exist that are related to stress/anxiety and depression within the normal range. Results demonstrate substantial modifications of functional hemisphere asymmetries in the modulation of EDA by these emotional factors and suggest that activation asymmetries in orbital and dorsolateral frontal regions reflect two different cortical sub-systems regulating electrodermal activity. The findings may, to some extent, provide an explanation for contradictory results in previous studies and may encourage research in psychosomatics and other clinical fields (e.g. schizophrenia).

Comparison between monorhinal and birhinal olfactory stimulations in bilateral electrodermal recordings

The study of olfactory lateralization in human subjects has given rise to many publications, but the findings have often been contradictory. Most research used either birhinal or monorhinal stimulations, but rarely a comparison between these two types of olfactory input. The aim of this study was to investigate variations in psychophysiological measurements and test each side of the nose and binasal performances. This work used bilateral electrodermal recordings and compared the skin conductance responses (SCRs) for a pleasant odorant (isoamyl acetate) and an unpleasant odorant (triethylamine) in a suprathreshold concentration on 30 dextral subjects (16 females and 14 males). First, the results reported no differences between the two nostrils but differences in electrodermal activity (EDA) in relation to the odorant: 1) higher amplitude in response to unpleasant versus pleasant odorant; 2) no differences between monorhinal and birhinal stimulations for the unpleasant odour but higher amplitude in response to birhinal versus monorhinal for the pleasant odour. Second, the results showed constant bilateral differences in EDA recordings and are discussed in terms of hemispheric asymmetry activation.

[Olfactory lateralization in humans: a review of the literature]

In the field of human perception, the chemical senses (taste and smell) have received little attention from neuroscience research when compared with auditory, visual and tactile senses. In the case of olfaction, it would appear that the publications over the last few years have been trying to overcome this lack of research. Many investigations have been carried out on lateralization, mainly in relation to specific pathologies (i.e., epilepsy, split-brain, lobotomy, etc.), while there have been few studies of healthy subjects. The results are often contradictory due particularly to special features of the olfactory system. However, consensus is emerging concerning, first, the fact that if both hemispheres are involved in the olfactory process, it is probable that one is more dominant than the other (many studies have revealed a greater impact on the right hemisphere in the treatment of olfactory information, but the dominance has not been clearly established). Second, the simple detection process would appear not to be lateralized whereas the higher-order olfactory tasks which involve memory processes and lexical aspects could be. The exact conditions governing lateralization still require more clarification by systematically taking into consideration the characteristics of the individual subjects, as well as those of the odorant stimuli and the test conditions. Finally, currently available techniques used in neurosciences and particularly cerebral imagery will contribute to a better understanding of the complexity of cerebral asymmetry in olfaction.

EEG correlates of behavioural laterality: right-handedness

Among right-handers, the magnitude of differences in proficiency between the left and right hands varies considerably. Yet significance of the extent of right-handedness is still a controversial issue. To examine whether individual differences in asymmetry of hand skill can partly be attributed to individual differences in asymmetrical hemispheric activation, handedness and electroencephalographic (EEG) laterality were correlated in two large samples (ns = 60 and 128). Analysis indicated that part of the variability in right-handedness may arise from activation asymmetries in the cortex, but whether this relation becomes apparent depends on the cortical area examined and on the experimental condition under which the EEG measures are taken.