Anterior EEG asymmetries and opponent process theory

The Effect of Long-Term Learning of BaduanJin on Emotion Regulation: Evidence from Resting-State Frontal EEG Asymmetry

Purpose

Baduanjin, as a Chinese traditional fitness exercise, can help people regulate emotions and promote their physical and psychological health. However, the underlying neural mechanisms have not been thoroughly explored. This study aimed to examine the effects of differences in the level of Baduanjin learning on individuals' brain and psychological response related to emotion regulation.

Methods

Twenty-two participants with long-term Baduanjin learning (for more than one year), and 21 participants with short-term Baduanjin learning (for approximately three months) were recruited. All participants were asked to do a complete 12-minute set of Baduanjin. Before and after doing Baduanjin, their resting-state EEG signals were collected, besides, the Emotion Regulation Questionnaire (ERQ) and the Profile of Mood States-Short Form (POMS-SF) were used to assess participants' emotion regulation strategies and abilities.

Results

The results of psychological measurement indicated that participants in the long-term group were more likely to use cognitive reappraisal as an emotion regulation strategy compared to participants in the short-term group (p<0.05). Moreover, the analysis of the frontal alpha asymmetry (FAA) showed that participants in the long-term group rather than the short-term group exhibited significant left lateralization after doing Baduanjin (p<0.05).

Conclusion

The findings provide preliminary evidence for the neural mechanism underlying how long-term Baduanjin learning promotes individuals' emotion regulation indexed by FAA. The study provides a new paradigm for research on how Baduanjin affects emotional regulation.

Analysis of EEG features and study of automatic classification in first-episode and drug-naïve patients with major depressive disorder

BACKGROUND

Major depressive disorder (MDD) has a high incidence and an unknown mechanism. There are no objective and sensitive indicators for clinical diagnosis.

OBJECTIVE

This study explored specific electrophysiological indicators and their role in the clinical diagnosis of MDD using machine learning.

METHODS

Forty first-episode and drug-naïve patients with MDD and forty healthy controls (HCs) were recruited. EEG data were collected from all subjects in the resting state with eyes closed for 10 min. The severity of MDD was assessed by the Hamilton Depression Rating Scale (HAMD-17). Machine learning analysis was used to identify the patients with MDD.

RESULTS

Compared to the HC group, the relative power of the low delta and theta bands was significantly higher in the right occipital region, and the relative power of the alpha band in the entire posterior occipital region was significantly lower in the MDD group. In the MDD group, the alpha band scalp functional connectivity was overall lower, while the scalp functional connectivity in the gamma band was significantly higher than that in the HC group. In the feature set of the relative power of the ROI in each band, the highest accuracy of 88.2% was achieved using the KNN classifier while using PCA feature selection. In the explanatory model using SHAP values, the top-ranking influence feature is the relative power of the alpha band in the left parietal region.

CONCLUSIONS

Our findings reveal that the abnormal EEG neural oscillations may reflect an imbalance of excitation, inhibition and hyperactivity in the cerebral cortex in first-episode and drug-naïve patients with MDD. The relative power of the alpha band in the left parietal region is expected to be an objective electrophysiological indicator of MDD.

Is Positive Affect as a Trait Related to Higher Heart Rate Variability in a Stressful Situation?

Most of the studies on the effect of trait positive affect (PA) and cardiovascular activity have focused on heart rate (HR) and blood pressure (BP) rather than heart rate variability (HRV). However, trait PA might sustain homeostasis for the autonomic system (ANS) by reducing activity in the sympathetic system (SNS) and increasing the activity in the parasympathetic system (PNS). A common index for the PNS is the vagal tone measured indirectly through HRV. The present study assessed whether trait PA influences cardiovascular response to various stress tasks by monitoring participants' HRV measured by RMSSD (root mean square of successive differences) along with HR and interbeat interval (IBI). A total of 54 participants performed various cognitive tasks and Trier Social Stress Tasks while their vital signs were monitored, and trait PA was measured with PANAS. The cognitive tasks included both high- and low-stress tasks, including fatigue-inducing 20 min Stroop tasks. The results showed overall higher HRV as measured by RMSSD for participants who have higher levels of trait PA, indicating more PNS activity compared with low-trait-PA individuals, particularly at the end of the task performance during the fatigue induction. High-trait-PA individuals also had a lower HR during the fatigue-inducing task and a higher IBI. The results support previous work by further indicating a more adaptive response and consequently better emotional regulation for high-trait-PA individuals in a complex, prolonged task setting.

Dysfunction of Emotion Regulation in Mild Cognitive Impairment Individuals Combined With Depressive Disorder: A Neural Mechanism Study

Depression increases the risk of progression from mild cognitive impairment (MCI) to dementia, where impaired emotion regulation is a core symptom of depression. However, the neural mechanisms underlying the decreased emotion regulation in individuals with MCI combined with depressive symptoms are not precise. We assessed the behavioral performance by emotion regulation tasks and recorded event-related electroencephalography (EEG) signals related to emotion regulation tasks simultaneously. EEG analysis, including event-related potential (ERP), event-related spectral perturbation (ERSP), functional connectivity and graph theory, was used to compare the difference between MCI individuals and MCI depressed individuals in behavioral performance, the late positive potential (LPP) amplitudes, neural oscillations and brain networks during the processing of emotional stimuli. We found that MCI depressed individuals have negative preferences and are prone to allocate more attentional resources to negative stimuli. Results suggested that theta and alpha oscillations activity is increased, and gamma oscillations activity is decreased during negative stimulus processing in MCI depressed individuals, thus indicating that the decreased emotion regulation in MCI depressed individuals may be associated with enhanced low-frequency and decreased high-frequency oscillations activity. Functional connectivity analysis revealed a decrease in functional connectivity in the left cerebral hemisphere of the alpha band and an increase in functional connectivity in the right cerebral hemisphere of the alpha band in MCI depressed individuals. Graph theory analysis suggested that global network metrics, including clustering coefficients and disassortative, decreased, while nodal and modular network metrics regarding local nodal efficiency, degree centrality, and betweenness centrality were significantly increased in the frontal lobe and decreased in the parieto-occipital lobe, which was observed in the alpha band, further suggesting that abnormal alpha band network connectivity may be a potential marker of depressive symptoms. Correlational analyses showed that depressive symptoms were closely related to emotion regulation, power oscillations and functional connectivity. In conclusion, the dominant processing of negative stimuli, the increased low-frequency oscillations activity and decreased high-frequency activity, so as the decrease in top-down information processing in the frontal parieto-occipital lobe, results in the abnormality of alpha-band network connectivity. It is suggested that these factors, in turn, contribute to the declined ability of MCI depressed individuals in emotion regulation.

Transcranial Direct Current Stimulation Over the Left Dorsolateral Prefrontal Cortex Reduced Attention Bias Toward Negative Facial Expression: A Pilot Study in Healthy Subjects

Research in the cognitive neuroscience field has shown that individuals with a stronger attention bias for negative information had higher depression risk, which may be the underlying pathogenesis of depression. This dysfunction of affect-biased attention also represents a decline in emotion regulation ability. Clinical studies have suggested that transcranial direct current stimulation (tDCS) treatment can improve the symptoms of depression, yet the neural mechanism behind this improvement is still veiled. This study aims to investigate the effects of tDCS on affect-biased attention. A sample of healthy participants received 20 min active (n = 22) or sham tDCS (n = 19) over the left dorsolateral prefrontal cortex (DLPFC) for 7 consecutive days. Electroencephalographic (EEG) signals were recorded while performing the rest task and emotional oddball task. The oddball task required response to pictures of the target (positive or negative) emotional facial stimuli and neglecting distracter (negative or positive) or standard (neutral) stimuli. Welch power spectrum estimation algorithm was applied to calculate frontal alpha asymmetry (FAA) in the rest task, and the overlapping averaging method was used to extract event-related potentials (ERP) components in the oddball task. Compared to sham tDCS, active tDCS caused an obvious increment in FAA in connection with emotion regulation (p < 0.05). Also, participants in the active tDCS group show greater P3 amplitudes following positive targets (p < 0.05) and greater N2 amplitudes following negative distracters (p < 0.05), reflecting emotion-related attention biases. These results offer valuable insights into the relationship between affect-biased attention and the effects of tDCS, which may be of assistance in exploring the neuropathological mechanism of depression and anxiety and new treatment strategies for tDCS.

Psychophysiological responses to mobile reading: evidence from frontal EEG signals under a distracting reading environment and different text genres

Purpose

Reading represents a basic way by which humans understand the world and acquire knowledge; it is also central to learning and communicating. However, with the rapid development of mobile reading, an individual's cognition of objective facts may be affected by the reading environment and text genre, resulting in limited memorization and understanding of the reading material. Therefore, this study aimed to investigate the influence of the reading environment and text genre on individuals' cognitive activities from the perspective of motivational activation level using evidence from electroencephalography (EEG) signals.

Design/methodology/approach

The study employed a mixed design experiment with two reading environments (quiet and distracting) between subjects, two text genres (entertaining and scientific) within subjects and two reading tasks (memory recall and comprehension) within subjects. There were 50 participants in the experiment, and the data obtained from 44 participants while they read the materials and completed the reading tasks were analyzed.

Findings

The results showed that readers are more positively motivated to read in a quiet reading environment than in a distracting reading environment when facing the memory recall tasks of entertaining genre passages and comprehension tasks of scientific genre passages. Entertaining genres are more likely to arouse readers' reading interest but hinder the memory recall of the content details. While scientific genres are not easy to understand, they are helpful for working memory.

Originality/value

This study not only applies a new technology to mobile reading research in the field of library science and addresses the limitations of self-report data, but also provides suggestions for the further improvement of mobile reading service providers. Additionally, the results may provide useful information for learners with different learning demands.

Differentiating reactivity and regulation: Evidence for a role of prefrontal asymmetry in affect regulation

Prefrontal asymmetry (PFA) has originally been referred to as "affective style" and is said to be associated with an individual's personality. Therefore, previous research has focused on finding a link between PFA and trait variables associated with affective processing, such as the behavioral activation and inhibition systems (BAS/BIS). However, recent evidence suggests that PFA might be involved in regulatory processes rather than initial affective reactions. Here, we investigated if failure-related action orientation (AOF), as a personality variable reflecting the ability to disengage from negative experiences, is related to PFA. Forty-seven participants completed two trait questionnaires to assess BAS/BIS and AOF, followed by 8 min of resting EEG measurement. Results showed that higher AOF scores predicted a higher relative left-hemispheric PFA when BAS/BIS was controlled for. The findings suggest that a suppression effect might account for the inconsistencies in the literature regarding the association between PFA and BAS/BIS.

Working memory training improves emotion regulation in drug abstainers: Evidence from frontal alpha asymmetry

Drug addiction has been associated with unsuccessful emotion regulation, which can be improved by working memory training (WMT) in healthy populations. This study aimed to assess the effect of WMT on emotion regulation in drug abstainers. We divided 40 male drug abstainers into two groups: (i) the training group (n=20) participated in a running memory task for 20 days, and (ii) the control group (n=20) did not participate in any training task. We assessed the emotion regulation questionnaire (ERQ) and frontal electroencephalographic (EEG) activity while viewing pictures (including neutral, positive, negative and drug-related contents) for all participants before and after the training. After WMT for 20 days, the training group adopted more spontaneous emotion regulation strategies compared with control group. The asymmetry scores of training group improved while viewing negative and drug-related pictures compared to pretest, which suggests that they converted from right-brain asymmetry to left-brain asymmetry. However, the control group declined both in the ERQ scores and the asymmetry scores. These results suggest that WMT improves the emotion regulation of drug abstainers.

The Functional Role of Individual Alpha-Based Frontal Asymmetry in the Processing of Fearful Faces

The ability to quickly identify fearful faces is important for the activation of defense mechanisms that allow an individual to deal with potential emergencies. This study examined the relationship between frontal electroencephalography (EEG) alpha asymmetry and the processing of congruent and incongruent fearful faces among female participants using event-related potentials (ERPs). Behavioral results showed that individuals with more left frontal EEG alpha asymmetry had shorter response times than individuals with more right frontal EEG alpha asymmetry during the cue-target task. ERP results indicated that, for individuals with more left frontal EEG alpha asymmetry, enhanced N1 reflected more rapid processing of emotional faces in the early stage, and enhanced P3 indicated that these individuals directed more attentional and motivational resources to the evaluation of emotional faces in the late stage. For individuals with more right frontal EEG alpha asymmetry, enhanced N2 indicated that these individuals experienced more conflict for incongruent fearful faces in the late stage. The present findings suggest that frontal EEG alpha asymmetry during resting conditions can reflect individual differences in the processing of congruent and incongruent fearful faces.

Performance anxiety and the plasticity of emotional responses

Current psychological theories of performance anxiety focus heavily on relating performers' physiological and mental states to their abilities to maintain focus and execute learned skills. How task-specific expertise and past experiences moderate the degree to which individuals become anxious in a given performance context are not well accounted for within these theories. This review considers how individual differences arising from learning may shape the psychobiological, emotional, and cognitive processes that modulate anxious states associated with the performance of highly trained skills. Current approaches to understanding performance anxiety are presented, followed by a critique of these approaches. A connectionist model is proposed as an alternative approach to characterising performance anxiety by viewing performers' anxious states at a specific time point as jointly determined by experience-dependent plasticity, competition between motivational systems, and ongoing cognitive and somatic states. Clarifying how experience-dependent plasticity contributes to the emergence of socio-evaluative anxiety in challenging situations can not only help performers avoid developing maladaptive emotional responses, but may also provide new clues about how memories of past events and imagined future states interact with motivational processes to drive changes in emotional states and cognitive processing.

Dominant and opponent relations in cortical function: An EEG study of exam performance and stress

This paper analyzes the opponent dynamics of human motivational and affective processes, as conceptualized by RS Solomon, from the position of AA Ukhtomsky's neurophysiological principle of the dominant and its applications in the field of human electroencephalographic analysis. As an experimental model, we investigate the dynamics of cortical activity in students submitting university final course oral examinations in naturalistic settings, and show that successful performance in these settings depends on the presence of specific types of cortical activation patterns, involving high indices of left-hemispheric and frontal cortical dominance, whereas the lack thereof predicts poor performance on the task, and seems to be associated with difficulties in the executive regulation of cognitive (intellectual) and motivational processes in these highly demanding and stressful conditions. Based on such knowledge, improved educational and therapeutic interventions can be suggested which take into account individual variability in the neurocognitive mechanisms underlying adaptation to motivationally and intellectually challenging, stressful tasks, such as oral university exams. Some implications of this research for opponent-process theory and its closer integration into current neuroscience research on acquired motivations are discussed.

Prediction of subjective ratings of emotional pictures by EEG features

OBJECTIVE

Emotion dysregulation is an important aspect of many psychiatric disorders. Brain-computer interface (BCI) technology could be a powerful new approach to facilitating therapeutic self-regulation of emotions. One possible BCI method would be to provide stimulus-specific feedback based on subject-specific electroencephalographic (EEG) responses to emotion-eliciting stimuli.

APPROACH

To assess the feasibility of this approach, we studied the relationships between emotional valence/arousal and three EEG features: amplitude of alpha activity over frontal cortex; amplitude of theta activity over frontal midline cortex; and the late positive potential over central and posterior mid-line areas. For each feature, we evaluated its ability to predict emotional valence/arousal on both an individual and a group basis. Twenty healthy participants (9 men, 11 women; ages 22-68) rated each of 192 pictures from the IAPS collection in terms of valence and arousal twice (96 pictures on each of 4 d over 2 weeks). EEG was collected simultaneously and used to develop models based on canonical correlation to predict subject-specific single-trial ratings. Separate models were evaluated for the three EEG features: frontal alpha activity; frontal midline theta; and the late positive potential. In each case, these features were used to simultaneously predict both the normed ratings and the subject-specific ratings.

MAIN RESULTS

Models using each of the three EEG features with data from individual subjects were generally successful at predicting subjective ratings on training data, but generalization to test data was less successful. Sparse models performed better than models without regularization.

SIGNIFICANCE

The results suggest that the frontal midline theta is a better candidate than frontal alpha activity or the late positive potential for use in a BCI-based paradigm designed to modify emotional reactions.

The Functional Role of Individual-Alpha Based Frontal Asymmetry in the Evaluation of Emotional Pictures: Evidence from Event-Related Potentials

The perceptual processing of emotional stimuli is subject to the regulation of brain function. This study investigated whether frontal electroencephalography (EEG) alpha asymmetry at resting conditions predicted the evaluation of emotional picture stimuli by event-related potentials (ERPs). In this study, participants first completed a 2-min resting task, and then passively viewed emotional pictures. The results showed that left active individuals had smaller frontal EEG alpha asymmetry scores to negative pictures than to positive and neutral pictures, whereas right active individuals had similar frontal EEG alpha asymmetry scores to negative, positive, and neutral pictures. Furthermore, the study showed a larger P300 to negative pictures than to positive and neutral pictures for left active individuals; however, there were no significant ERP differences to negative, positive, and neutral pictures for right active individuals. These findings suggest that frontal EEG alpha asymmetry at resting conditions can reflect interindividual differences in emotional perception tendencies to emotional picture stimuli.

The dynamic opponent relativity model: an integration and extension of capacity theory and existing theoretical perspectives on the neuropsychology of arousal and emotion

Arousal theory as discussed within the present paper refers to those mechanisms and neural systems involved in central nervous system activation and more specifically the systems involved in cortical activation. Historical progress in the evolution of arousal theory has led to a better understanding of the functional neural systems involved in arousal or activation processes and ultimately contributed much to our current theories of emotion. Despite evidence for the dynamic interplay between the left and right cerebral hemispheres, the concepts of cerebral balance and dynamic activation have been emphasized in the neuropsychological literature. A conceptual model is proposed herein that incorporates the unique contributions from multiple neuropsychological theories of arousal and emotion. It is argued that the cerebral hemispheres may play oppositional roles in emotion partially due to the differences in their functional specializations and in their persistence upon activation. In the presence of a threat or provocation, the right hemisphere may activate survival relevant responses partially derived from hemispheric specializations in arousal and emotional processing, including the mobilization of sympathetic drive to promote heightened blood pressure, heart rate, glucose mobilization and respiratory support necessary for the challenge. Oppositional processes and mechanisms are discussed, which may be relevant to the regulatory control over the survival response; however, the capacity of these systems is necessarily limited. A limited capacity mechanism is proposed, which is familiar within other physiological systems, including that providing for the prevention of muscular damage under exceptional demand. This capacity theory is proposed, wherein a link may be expected between exceptional stress within a neural system and damage to the neural system. These mechanisms are proposed to be relevant to emotion and emotional disorders. Discussion is provided on the possible role of currently applied therapeutic interventions for emotional disorders.

Psychological Response to Sound Stimuli Evaluated by EEG

Abstract. Psychological responses to two kinds of sound stimuli (scary and soothing), as assessed by the Anterior Asymmetry and Emotion (AAE) and Comfort Vector (CV) models which are based on the prefrontal alpha wave, were investigated and the relation between their results is discussed. For the scary sound stimulus, subjects who showed greater withdrawal motivation (AAE) displayed a decreased pleasant state (CV), while subjects who showed higher approach motivation displayed opposite affective direction. There was a correlation between the AAE and CV models for the scary stimulus, but no correlation for the soothing stimulus. Both motivational and affective states could be evaluated by a combination of AAE and CV models. We suggest that joint consideration of these two models could lead to the multifaceted evaluation of a psychological state.

Unconscious and conscious processing of negative emotions examined through affective priming

This study investigated unconscious and conscious processes by which negative emotions arise. Participants (26 men, 47 women; M age = 20.3 yr.) evaluated target words that were primed with subliminally or supraliminally presented emotional pictures. Stimulus onset asynchrony was either 200 or 800 msec. With subliminal presentations, reaction times to negative targets were longer than reaction times to positive targets after negative primes for the 200-msec. stimulus onset asynchrony. Reaction times to positive targets after negative or positive primes were shorter when the stimulus onset asynchrony was 800 msec. For supraliminal presentations, reaction times were longer when evaluating targets that followed emotionally opposite primes. When emotional stimuli were consciously distinguished, the evoked emotional states might lead to emotional conflicts, although the qualitatively different effects might be caused when subliminally presented emotion evoking stimulus was appraised unconsciously; that possibility was discussed.

Predicting affective responses to exercise using resting EEG frontal asymmetry: does intensity matter?

Affective responses to exercise may be important for improving adherence to regular programs of exercise. The present study sought to determine whether resting frontal EEG asymmetry, an individual difference measure of affective style, is predictive of affective responses to exercise performed at distinct intensities standardized relative to a metabolic landmark (i.e., the ventilatory threshold, VT). Resting EEG was collected from 30 participants and used to predict affective responses following treadmill running at three exercise intensities: below-VT, at-VT, and above-VT. Affect was assessed [via Activation-Deactivation Adjective Check List, yielding measures of Energetic Arousal (EA) and Tense Arousal (TA)] before, immediately following exercise, after 5min cool down, and 10 and 20min post-cool down. Resting mid-frontal asymmetry (F4-F3) significantly predicted EA immediately following below-VT exercise; resting lateral frontal asymmetry (F8-F7) predicted EA at 20min post-cool down. Resting mid-frontal asymmetry predicted in EA immediately following and following cool down in above-VT exercise. As a whole, frontal asymmetry was predictive of affective responses following exercise, namely greater relative left frontal activity predicting lower EA. This was opposite to the predictions of the valenced motivation model, but may provide some support for the motivation direction model. This is based on the fact that low EA could be indicative of approach motivation, especially at higher exercise intensities.

Female menstrual phases modulate human prefrontal asymmetry: a magnetoencephalographic study

We previously reported that the trait/baseline prefrontal cortex (PFC) activity expresses a dynamic plasticity during female menstrual cycle. The shift of asymmetric lateralization of PFC baseline activity pinpoints a possible emotional regulation of negative affection. The current emotional Go/NoGo study aimed to investigate the state PFC responses of different menstrual phases during fear facial stimulation in fourteen healthy women. Our data disclosed that the menstrual cycle was coupled with a shift of asymmetric lateralization of frontal activation across different menstrual phases. Evoked magnetic field activity in the time window 200-300 ms (M1) and 300-450 ms (M2) after stimulus onset demonstrated significant interactions between hemispheric side and menstrual phase. The right hemispheric dominance in periovulatory phase (OV) changed to left hemispheric dominance in menstrual (MC) phase. Significant association between the anxiety score and the left PFC activation was particularly observed in MC phase. Our study revealed a plastic resilience of functional organization of human brain and a dynamic automaticity of inter-hemispheric synergism for possible adaptive regulation under the aversive confrontation in accordance with hormonal fluctuation during the menstrual cycle.