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We conducted a pilot study to examine the relations among the patterns of resting regional electroencephalogram (EEG) alpha activity, trait shyness and sociability, and positive and negative symptoms scores in 20 adults with schizophrenia, attending a community-based treatment and rehabilitation center. As predicted, patients' positive symptoms were related to greater relative resting left frontal EEG activity, replicating earlier work. When only adults with low to no positive symptoms were considered, trait shyness was related to greater relative resting right frontal EEG activity, whereas trait sociability was related to greater relative resting left frontal EEG activity. This finding is similar to what is consistently noted in healthy adults. These pilot data suggest that positive symptoms in patients with schizophrenia may obscure the relations between personality and frontal EEG asymmetry measures observed in healthy adults.

Frontal alpha asymmetry is typically computed using alpha power averaged across many overlapping epochs. Previous reports have estimated the internal consistency reliability of asymmetry by dividing resting EEG sessions into segments of equal duration (e.g. 1 min) and treating asymmetry scores for each segment as “items” to estimate internal consistency reliability using Cronbach's alpha. Cronbach's alpha partly depends on the number of items, such that this approach may underestimate reliability by using less than the number of distinct items available. Reliability estimates for resting EEG data in the present study (204 subjects, 8 sessions) were obtained using mean split-half correlations with epoch alpha power as treated as separate items. Estimates at all scalp sites and reference schemes approached 0.90 with as few as 100 epochs, suggesting the internal consistency of frontal asymmetry is greater than that previously reported.

Although the pattern of resting frontal brain electrical activity (EEG) has been suggested as a “trait-like” correlate of individual differences in affective style in adults and children, there appear to be no studies that have examined the short-term stability of resting frontal EEG asymmetry measures in typically developing infants. A new approach was examined to study the short-term stability of resting frontal EEG asymmetry measures. Second-by-second frontal EEG asymmetry scores (right power minus left power) were computed across a 90 s baseline condition in a group of 52 typically developing 9-month-old human infants. Using the distribution characteristics (i.e., mean and variance) of the individual frontal EEG asymmetry scores, each infant was assigned to one of three asymmetry groups: Stable Right, Stable Left, and Variable. As predicted, infants in the Stable Right frontal asymmetry group exhibited a significantly higher baseline heart rate and were rated higher on maternal perception of fear at age 9 months compared with infants in the other two groups, replicating earlier work. These findings provide evidence of short-term stability (i.e., trait-like features) in frontal EEG asymmetry measures that index individual differences in infant temperament. Findings are discussed in terms of the utility of second-by-second frontal asymmetry scores to address developmental and maturational questions of individual differences in temperament.

Copyright: © 2016 Machado S et al. This is an open-access article distributed under the terms of the Creative Common Attributions License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Citation: Machado S, Lattari E, Paes F, et al. Is EEG asymmetry a predictor of mood in practitioners of aerobic exercise?. 2016. 2:2.

Depressive disorders shows an alpha EEG asymmetry with higher activation in the left anterior brain. This phenomenon might be associated with the strengthened negative activities in the right side of the brain, especially the information related to self-concept. However, it is absent of direct evidence to support the relationship between the alpha EEG asymmetry and self-concept, and it is not clear what the variation of the correlation between the two factors in depressive disorders. To investigate the issues, we collected the resting EEG data with eye-closed and the self-consciousness level data to compare the relationship between alpha EEG asymmetry and self-concept in depression patients and healthy controls. Results show that both the two groups have strong correlations between the self-consciousness and alpha asymmetry in the brain, but differed in the correlation patterns. Depressions show that self-consciousness is correlated with the more anterior alpha EEG asymmetry in the brain, while the healthy group correlate with the more posterior alpha asymmetry. These results indicate that the impairment of the correlation between self-concept and alpha asymmetry in depressive disorders might be a biomarker of the disease to be considered in future study.

This study examines the moderating influences of dispositional behavioral activation system (BAS) and behavioral inhibition system (BIS) sensitivities on approach/withdrawal motivation responses measured using frontal electroencephalographic (EEG) alpha asymmetry during reading of a newspaper on the traditional print medium and a tablet. The dispositional BAS and BIS sensitivities of the participants were measured using the BIS/BAS scales. Reading the print newspaper induced relatively greater left frontal cortical activation, suggesting higher approach motivation during reading on paper than on a tablet. BAS Drive and BAS Fun Seeking showed significant moderating effects on frontal EEG asymmetry, higher Drive and Fun Seeking scores predicted lower approach motivation in the tablet reading condition than in the print condition. In contrast, higher Reward Responsiveness predicted higher approach motivation in the tablet reading condition. The conclusion of the paper is that, dispositional BAS sensitivity has a moderating influence on the approach motivation towards a reading medium.

The aim of the current study was to investigate the effect of a naturalistic stressor, examination stress, on frontal EEG asymmetry, psychological stress, hormonal stress, and negative health. Forty-nine subjects were tested during periods of low and high examination stress. During the high examination stress period, subjects reported higher levels of stress on the Spielberger State Anxiety Inventory and Cohen's Perceived Stress Scale. However, no change in cortisol was detected across the two sessions. Furthermore, a shift from relatively greater left frontal activity during the low examination session to relatively greater right frontal activity during the high examination session was also found. Moreover, the increasing right frontal activity asymmetry associated with the high exam session compared to the low exam session correlated with increasing reports of negative health. No evidence was found for the prediction that cortisol mediated either the relationship between examination stressor and right frontal asymmetry or between right frontal asymmetry and negative health. In conclusion, while the findings from this study are compelling, the mechanism mediating increases in psychological stress, relatively greater right frontal activity, and increases in negative health from naturally occurring stressors is in need of further investigation.

The current study was a multilevel investigation of resilience, emotion regulation, and hemispheric electroencephalogram (EEG) asymmetry in a sample of maltreated and nonmaltreated school age children. It was predicted that the positive emotionality and increased emotion regulatory ability associated with resilient functioning would be associated with relatively greater left frontal EEG activity. The study also investigated differences in pathways to resilience between maltreated and nonmaltreated children. The findings indicated that EEG asymmetry across central cortical regions distinguished between resilient and nonresilient children, with greater left hemisphere activity characterizing those who were resilient. In addition, nonmaltreated children showed greater left hemisphere EEG activity across parietal cortical regions. There was also a significant interaction between resilience, maltreatment status, and gender for asymmetry at anterior frontal electrodes, where nonmaltreated resilient females had greater relative left frontal activity compared to more right frontal activity exhibited by resilient maltreated females. An observational measure of emotion regulation significantly contributed to the prediction of resilience in the maltreated and nonmaltreated children, but EEG asymmetry in central cortical regions independently predicted resilience only in the maltreated group. The findings are discussed in terms of their meaning for the development of resilient functioning.

Previous research using the model proposed by Davidson has shown that resting frontal electroencephalographic (EEG) asymmetry can predict affective responses to aerobic exercise at moderate intensities. Specifically, greater relative left frontal activity has been shown to predict positive affect (i.e., energy) following exercise. The purpose of this study was to determine if resting frontal EEG asymmetry would predict affective responses following strenuous exercise. Thirty participants (13 women, 17 men) completed a maximal graded exercise test on a treadmill. EEG was recorded prior to exercise. Affect was measured by the Activation Deactivation Adjective Check List prior to the graded exercise test, immediately following, 10 and 20-min following exercise. Greater relative left frontal activity predicted tiredness and calmness during recovery from exercise, but not tension or energy. Tiredness and calmness following exercise covaried, suggesting that tiredness following exercise might not have been linked with displeasure. These findings offer further support for the link between EEG asymmetry and affective responses to exercise.

Frontal EEG asymmetry is a promising neurophysiological marker of depression risk. It predicts emotional response and negative affect hours to years later. Yet, inconsistencies in the literature may be due to differing methodological approaches between research groups. Within the past two years, a number of studies have shown this line of research may be strengthened by augmenting resting assessments with emotionally evocative tasks, utilizing optimal recording montages, and taking an integrative neuroscience approach that links frontal asymmetry to other indices of neural function. This review will focus on recent work in frontal asymmetry and depression with a particular focus on promising future directions and methodological considerations that may increase consistency between research groups.

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. Published version

Depression has been described as a process of behavioural withdrawal from overwhelming aversive stressors, and which manifests itself in the diagnostic symptomatology for Major Depressive Disorder (MDD). The underlying neurobiological pathways to that behavioural withdrawal are suggested to include greater activation in the right vs the left frontal lobes, described as frontal EEG asymmetry. However, despite a previous meta-analysis that provided overall support for this EEG asymmetry hypothesis, inconsistencies and several methodological confounds exist. The current review examines the literature on this issue, identifies inconsistencies in findings and discusses several key research issues that require addressing for this field to move towards a defensible theoretical model of depression and EEG asymmetry. In particular, the position of EEG asymmetry in the brain, measurement of severity and symptoms profiles of depression, and the effects of gender are considered as potential avenues to more accurately define the specific nature of the depression-EEG asymmetry association.

Previous research has shown that those reporting symptoms of depression and anxiety tend to exhibit greater relative right frontal electroencephalographic (EEG) activity. Thus, Davidson [Davidson, R.J., 1995. Cerebral asymmetry, emotion, and affective style. In: Davidson, R.J., Hugdahl, K. (Eds.), Brain Asymmetry. MIT, Cambridge, pp. 361-387] has suggested that greater relative right anterior activity may act as a vulnerability marker for the development of depression and anxiety disorders. This study therefore examined whether anterior and posterior EEG asymmetry patterns predicted anxiety and depressive symptoms one year later. At time 1, participants completed the Beck Depression Inventory (BDI) and State-Trait Anxiety Inventory (STAI) and had baseline EEG activity recorded. Participants then completed the BDI and STAI one year later. Those with relatively greater EEG activity in the right anterior region reported greater trait anxiety one year later. These preliminary results suggest that relative right frontal EEG activity may predict future development of anxiety symptoms.

[Purpose] The purpose of this preliminary study was to investigate the effect of manual lymph drainage (MLD) of the neck on frontal electroencephalogram (EEG) asymmetry in subjects with psychological stress. [Subjects] Thirteen subjects with psychological stress participated in the study. [Methods] Subjects received MLD of the neck for 15 min. [Results] Analysis of the frontal asymmetry index showed that the energy shift in the alpha frequency band from the left hemisphere to the right hemisphere after MLD resulted in greater left-side activation (positive asymmetry values), which could be related to the positive emotional state observed particularly in the F7–F8 area. [Conclusion] These preliminary findings suggest that frontal EEG asymmetry was significantly attenuated after MLD.

The current study examined how reactions to a negative mood manipulation and a rumination/distraction task differed between high defensive (HD) and low defensive (LD) individuals. At baseline, high defensive participants exhibited significantly greater relative left frontal EEG activity than low defensive participants. HD also exhibited greater relative left anterior activity during both the negative mood induction and during the rumination/distraction task, regardless of group assignment. Contrary to predictions, there were no differences in self-reported mood between HD and LD in either the rumination or distraction group. A significant interaction was found between gender and group, indicating that anterior alpha asymmetry patterns differed for men and women during the rumination/distraction task.

EEG responses to mothers’ and strangers’ mock facial expressions (happy, surprised and sad) during a peek-a-boo game were recorded in 60, 3- to 6-month-old infants of depressed and non-depressed mothers. The infants of depressed mothers exhibited less positive and more negative affect and were less likely to look at the facial expressions displayed by both their mother and a stranger. The infants of depressed mothers showed greater relative right frontal EEG asymmetry than the infants of non-depressed mothers throughout the different expressions of the mothers and strangers and showed elevated salivary cortisol levels after the session. Both groups of infants showed significantly greater right frontal asymmetry during their mothers’ and stranger’s sad versus happy expression. In addition, infants showed greater right frontal EEG asymmetry during the stranger’s surprised versus happy expression.

In recent years research on physiological response and frontal electroencephalographic (EEG) asymmetry in different patterns of infant and adult attachment has increased. We review research findings regarding associations between attachment classifications and frontal EEG asymmetry, the autonomic nervous system (ANS) and the hypothalamic-pituitary-adrenocortical axis (HPA). Studies indicate that insecure attachment is related to a heightened adrenocortical activity, heart rate and skin conductance in response to stress, which is consistent with the hypothesis that attachment insecurity leads to impaired emotion regulation. Research on frontal EEG asymmetry also shows a clear difference in the emotional arousal between the attachment groups evidenced by specific frontal asymmetry changes. Furthermore, we discuss neurophysiological evidence of attachment organization and present up-to-date findings of EEG-research with adults. Based on the overall patterns of results presented in this article we identify some major areas of interest and directions for future research.

Previous research relating anterior asymmetry in the electroencephalogram (EEG) to emotional states has not taken the affective context of the testing environment into account. This may be an important consideration, as the preparation procedures themselves are somewhat aversive. The purpose of this study was to assess whether self-reported mood state before and/or after EEG cap preparation was associated with EEG asymmetry. Mood state was assessed with the self-assessment manikin before and after the application of the electrode cap. Men and women showed a shift toward a more negative mood state post-preparation. Negative mood post-preparation, but not pre-preparation, predicted relative right frontal activation in men. In contrast, negative mood post-preparation, but not pre-preparation, predicted relative left frontal activation in women. Results are discussed as they relate to gender differences in interpersonal engagement.

We recorded an electroencephalogram from the two hemispheres, a neck musculature electromyogram, an electrooculogram, and respiratory acts during sleep and wakefulness on land in three 1-year-old sea lion females for 3 or 4 consecutive days. On average active wakefulness (AW) occupied 20.4+/-2.0% of the 24-h period; quiet wakefulness (QW) 54.9+/-2.5%; slow wave sleep (SWS) 15.0+/-2.5% and paradoxical sleep (PS) 9.7+/-2.0%. Between 30 and 50% (average 39.1+/-3.4%) of total sleep time was spent in PS. From 8 to 31 episodes of PS were recorded per day (average 17+/-6 per day), with the longest episode lasting 20 min (average 5.6+/-0.5 min). Episodes of interhemispheric EEG asymmetry accounted for 5.5+/-1.3% of total SWS time. Respiratory pauses in these animals varied in QW between 4 and 36 s (average 15.7+/-0.4 s), in SWS between 11 and 37 s (20.9+/-0.6 s) and in PS between 2 and 69 s (15.0+/-1.5 s). AW, QW, SWS and PS were approximately equally distributed between light (07:00-19:00) and dark time (19:00-07:00). The low amount of SWS with interhemispheric EEG asymmetry, the high proportion of PS in total sleep time and the nearly even distribution of sleep and wakefulness over the 24-h period could be both species-specific features and/or ontogenetic characteristics of the animals studied.

Based on the approach-withdrawal model of hemispheric asymmetry, anger and aggression have been linked to an approach-related pattern, characterized by stronger relative left-hemispheric anterior cortical activity. Recent work suggests that also in individuals with extremely violent tendencies, such as imprisoned offenders, approach-related asymmetry may be associated with self-reported trait anger and aggression. A putative association between alpha asymmetry and further characteristics relevant for aggression, such as callous-unemotional (CU) traits, remains to be explored. CU traits may increase the probability of aggressive behavior; nevertheless, they may also enable individuals to inhibit and postpone the overt display of aggression until circumstances grant its strongest impact. In the current exploratory study, we measured trait aggression, CU traits, and resting-state EEG asymmetry in the alpha band (8-13 Hz) in imprisoned violent offenders in a German high security prison. Results revealed that particularly trait callousness was associated with stronger relative right-hemispheric anterior cortical activity (i.e., a withdrawal-related pattern). An association between alpha asymmetry and aggression was not replicated. These preliminary findings suggest that, due to the involved emotional and interpersonal detachment, callousness might be withdrawal related, despite its potential to bring about aggressive behavior. They also imply that the identification of putative clinical subtypes in prisoners is required, as varying psychopathology might undermine an association between alpha asymmetry and aggression.

Maternal negative affect in the early environment is believed to sensitize long-term coping capacities in children. Yet, little work has identified physiological systems associated with coping responses, which may serve as mechanisms for links between early maternal negativity and child outcomes. Using a longitudinal twin sample ( N = 89), we found that high levels of maternal negative affect during infancy were associated with dysregulation of diurnal cortisol and electroencephalograph (EEG) asymmetry, two physiological systems that may support active approach-oriented coping when children are 7 years old. Flattened slopes of diurnal cortisol were also associated with greater numbers of concurrent overanxious behaviors in children. A mediation analysis supported the role of dysregulated diurnal cortisol as a mediator of the link between maternal negative affect in the early environment and childhood risk for anxiety problems.

Two motivational systems underlie behaviour and affective responses - an inhibition/avoidance system and an activation/approach system. The purpose of the present study was to explore if individual differences in these motivational systems would occur in response to common weight and body composition testing within a sample of young, adult women. Electroencephalogram was used to distinguish approach or avoidance orientations via frontal asymmetry before and after testing sessions. Clear distinctions in motivational response were found, with 65% of the sample responding with an approach motivation, while 35% responded with an avoidance motivation. Even though all participants, on average, experienced a negative affective response, only the avoidance group self-reported a subsequent increase in "comfort food" consumption of desserts and snacks the week following the testing session. As shown with other stressors, clear individual differences exist in motivational responses to common weight and body composition testing. Such testing produces a general negative affective response; however, the individual differences in motivational responses might produce different behavioural choices. Future research and interventions in health communication should be considerate to this variation in motivational responses to help explain changes in both healthy and unhealthy behaviours following interactions involving one's body weight and/or body composition.

Asymmetry in frontal electrical activity has been suggested to index tendencies in affective responding and thus may be associated with hormonal stress responses. To assess the functional role of frontal asymmetry (FA) in stress, we measured FA at rest and following exposure to acute stress induced with the Maastricht Acute Stress Task (MAST; N = 70) in the standard 8-13 Hz band as well as based on individual alpha frequency (IAF) band. IAF-based resting FA(F4-F3) was associated with the stress induced neuroendocrine response, such that left individual frontal activity predicted smaller total cortisol increases in response to the MAST. Like previous studies, we found resting left-sided FA(F8-F7) to predict trait behavioural activation measured with the BIS/BAS scales. FA remained unaffected by stress-induced cortisol response. These findings suggest that individual FA might reflect a trait-like characteristic that moderates the stress response. Our results underscore the utility of IAF in studying individual differences in stress responding. (C) 2014 Elsevier B. V. All rights reserved.

Asymmetry of frontal cortical electroencephalogram (EEG) activity in children is influenced by the social environment and considered a marker of vulnerability to emotional and behavioral problems. To determine the reliability of these associations, we used meta-analysis to test whether variation in resting frontal EEG asymmetry is consistently associated with (a) having experienced psychosocial risk (e.g., parental depression or maltreatment) and (b) internalizing and externalizing behavior outcomes in children ranging from newborns to adolescents. Three meta-analyses including 38 studies (N = 2,523) and 50 pertinent effect sizes were carried out. The studies included in the analyses reported associations between frontal EEG asymmetry and psychosocial risk (k = 20; predominantly studies with maternal depression as the risk factor) as well as internalizing (k = 20) and externalizing (k = 10) behavior outcomes. Psychosocial risk was significantly associated with greater relative right frontal asymmetry, with an effect size of d = .36 (p

Using recent regional brain activation/emotion models as a theoretical framework, we examined whether the pattern of regional EEG activity distinguished emotions induced by musical excerpts which were known to vary in affective valence (i.e., positive vs. negative) and intensity (i.e., intense vs. calm) in a group of undergraduates. We found that the pattern of asymmetrical frontal EEG activity distinguished valence of the musical excerpts. Subjects exhibited greater relative left frontal EEG activity to joy and happy musical excerpts and greater relative right frontal EEG activity to fear and sad musical excerpts. We also found that, although the pattern of frontal EEG asymmetry did not distinguish the intensity of the emotions, the pattern of overall frontal EEG activity did, with the amount of frontal activity decreasing from fear to joy to happy to sad excerpts. These data appear to be the first to distinguish valence and intensity of musical emotions on frontal electrocortical measures.

EEG recordings were conducted with preschool children during presentations of videotaped vignettes depicting a fictional young child experiencing happy, sad, angry, and fearful events. Significant EEG asymmetry in the frontal region (left frontal activation) occurred during all types of emotional vignettes, but not during baseline periods (a neutral star-field image presented before and after each vignette). This pattern of left frontal cortical activation during each emotional vignette may represent a generally positive and low intensity emotional “approach” response even in the case of the negative emotion vignettes. These children displayed mostly neutral facial expressions during the vignettes, with some evidence of lip movements during the negative episodes (suggesting that the stories were eliciting some mild emotional responses or empathy). There was no evidence of more intense emotional responses that have been associated with right frontal cortical activation. These EEG patterns may reflect cortical mechanisms underlying mild emotional responses and affective displays in preschool children, as well as their developing ability to regulate their affective systems.

Les differences entre des meres deprimees de style different, importunes et renfermees, ont ete examinees par l'utilisation des Echelles de Comportement d'Inhibition et d'Activation (abrege BIS/BAS en anglais) et une activite electroencephalographique des regions parietales et mi-frontales. Les analyses ont revele que les meres renfermees avaient une hypoactivation de l'electroencephalographie frontale gauche, un score de Comportement d'Inhibition (abrege BIS, en anglais) plus eleve et un score Comportement d'Activation (abrege BAS, en anglais) inferieur que les meres importunes. Des analyses plus poussees montrerent que le BIS, la recompense BAS et les difference de scores BAS-BIS etaient lies a une asymetrie electroencephalographique frontale et a des scores d'autorite. Les scores BIS etaient aussi lies au style d'interaction renferme des meres, ce qui soutient l'utilisation du BIS/BAS en tant qu'instrument de depistage pour identifer les meres deprimees importunes et renfermees.

Aquatic mammals (i.e., Cetaceans, eared seals and manatees) and birds show interhemispheric asymmetries (IA) in slow-wave sleep-related electroencephalographic (EEG) activity, suggesting that the depth of sleep differs between hemispheres. In birds, an association between unilateral eye closure and IA has been reported in five species from three orders (i.e., Galliformes, Charadriiformes, and Anseriformes). Moreover, unilateral eye closure has been observed during behaviorally defined sleep in 29 species from 13 avian orders, suggesting that birds in general display IA during sleep. Despite the apparent prevalence of unilateral eye closure and IA in birds, previous work did not detect IA in the pigeon, thereby challenging the conclusion that this is a general feature of birds. Using digital period amplitude analysis, an objective method for quantifying EEG power (a measure of wave amplitude) across different frequencies, we demonstrate that pigeons do, in fact, display an association between unilateral eye closure and IA. For a given hemisphere, standardized 2–4 Hz EEG power was greater when the contralateral eye was closed when compared to open. We also found that pigeons used the open eye during IA to monitor their environment. In addition, individual pigeons showed a bias for keeping one eye open more than the other. The direction (left vs. right) of this bias differed across birds, and appeared to be influenced by the structure of the surrounding environment. Finally, with the addition of pigeons (order Columbiformes), IA associated with unilateral eye closure has been recorded in four avian orders, suggesting that this form of sleep is widespread in birds.

In order to evaluate the relationship between frontal EEG asymmetry and depressive symptomology, the Center for Epidemiological Studies Depression scale [CES-D; Radloff, 1977] was given to 163 women, and their EEG was recorded from the mid frontal (F3 and F4) and parietal (P3 and P4) regions during a 3 min baseline recording. As expected from previous research on depression, CES-D scores were negatively correlated with frontal EEG alpha asymmetry scores and positively correlated with left frontal EEG alpha power. Analyses of variance further revealed that mothers scoring above the cut-off for depression (CES-D > or = 16) had significantly lower frontal EEG asymmetry scores than mothers with 0-2 and 3-12 CES-D scores but not lower scores than mothers with 13-15 CES-D scores.

We investigate the problems that might arise when two recently developed methods for detecting interdependencies between time series using state space embedding are applied to signals of different complexity. With this aim, these methods were used to assess the interdependencies between two electroencephalographic channels from 10 adult human subjects during different vigilance states. The significance and nature of the measured interdependencies were checked by comparing the results of the original data with those of different types of surrogates. We found that even with proper reconstructions of the dynamics of the time series, both methods may give wrong statistical evidence of decreasing interdependencies during deep sleep due to changes in the complexity of each individual channel. The main factor responsible for this result was the use of an insufficient number of neighbors in the calculations. Once this problem was surmounted, both methods showed the existence of a significant relationship between the channels which was mostly of linear type and increased from awake to slow wave sleep. We conclude that the significance of the qualitative results provided for both methods must be carefully tested before drawing any conclusion about the implications of such results.

Previous case studies are presented which demonstrate the effectiveness of Alpha Asymmetry EEG biofeedback training in the treatment of depression. The results of these studies suggest that this form of biofeedback training may be an effective adjunct in the treatment of depression. To date, these case studies have been conducted on adults. This is the first attempt to replicate and extend the adultstudies using an adolescent client.

In 11 non-depressed, age-matched controls, and in 13 depressed patients, we compared the frontal alpha asymmetry mean for a baseline session with the percentage of the time in the session when the asymmetry score > 0. It was found that the percent index was a better discriminator of the two groups than was the asymmetry score.

Individual differences in emotional reactivity or affective style can be decomposed into more elementary constituents. Several separable of affective style are identified such as the threshold for reactivity, peak amplitude of response, the rise time to peak and the recovery time. latter two characteristics constitute components of affective chronometry The circuitry that underlies two fundamental forms of motivation and and withdrawal-related processes-is described. Data on differences in functional activity in certain components of these are next reviewed, with an emphasis on the nomological network of surrounding individual differences in asymmetric prefrontal The relevance of such differences for understanding the nature affective dysfunction in affective disorders is then considered. The ends by considering what the prefrontal cortex “does” in certain of affective style and highlights some of the important questions for future research.

Sixty-three infants of mothers with depressive symptoms were compared on physiology and behavior to infants of nonsymptomatic mothers. The newborns of depressive mothers had greater relative right frontal EEG asymmetry (due to reduced left hemisphere activation), lower vagal tone, and less optimal scores on the Brazelton, suggesting that maternal depressive symptoms during pregnancy may be contributing to newborn neurobehavioral functioning.

Although motivational disturbances are common in schizophrenia, their neurophysiological and psychological basis is poorly understood. This electroencephalography (EEG) study examined the well-established motivational direction model of asymmetric frontal brain activity in schizophrenia. According to this model, relative left frontal activity in the resting EEG reflects enhanced approach motivation tendencies, whereas relative right frontal activity reflects enhanced withdrawal motivation tendencies. Twenty-five schizophrenia outpatients and 25 healthy controls completed resting EEG assessments of frontal asymmetry in the alpha frequency band (8–12 Hz), as well as a self-report measure of behavioral activation and inhibition system (BIS/BAS) sensitivity. Patients showed an atypical pattern of differences from controls. On the EEG measure patients failed to show the left lateralized activity that was present in controls, suggesting diminished approach motivation. On the self-report measure, patients reported higher BIS sensitivity than controls, which is typically interpreted as heightened withdrawal motivation. EEG asymmetry scores did not significantly correlate with BIS/BAS scores or with clinical symptom ratings among patients. The overall pattern suggests a motivational disturbance in schizophrenia characterized by elements of both diminished approach and elevated withdrawal tendencies.

Nowadays, there is a growing interest in measuring emotions through the estimation of cerebral variables. Several techniques and methods are used and debated in neuroscience. In such a context, the present paper provides examples of time-varying variables related to the estimation of emotional valence, arousal and Approach-Withdrawal behavior in marketing relevant contexts. In particular, we recorded electroencephalographic (EEG), galvanic skin response (GSR) and heart rate (HR) in a group of healthy subjects while they are watching different TV commercials. Specifically, results obtained in the Experiment 1 shows a significant increase of cortical power spectral density across left frontal areas in the alpha band and an enhance of cardiac activity during the observation of TV commercials that have been judged pleasant. In the Experiment 2, frontal EEG asymmetry, GSR and HR measurements are used to draw cognitive and emotional indices in order to track the subject’s internal state frame by frame of the commercial. A specific case study shows how the variations of the defined Approach-Withdrawal and emotional indices can distinguish the reactions of younger adults from the older ones during the observation of a funny spot. This technology could be of help for marketers to overcome some of the drawbacks of the standard marketing tools (e.g., interviews, focus groups) usually adopted during the analysis of the emotional perception of advertisements.

The electrophysiology technique now provides an alternative way to evaluate users' emotional states in real time, but how to confirm the valence of emotions using these techniques is still a concern to researchers. Frontal alpha asymmetry FAA is often used as an index of pleasantness or liking in neuromarketing, but results in related fields are not consistent. In this study, we investigated the emotional states of users interacting with mobile phone applications APPs using FAA. Twenty participants participated in this experiment. They were asked to complete several tasks in a scene of everyday life using three APPs of the same type. EEG data and subjective evaluations were recorded during the experiment. The FAA results showed a positive trend when using an APP that provided an excellent user experience. The mechanism of emotional change during interacting with mobile applications and the implications of this research are also discussed in this study.

Previous research has documented differences in the pattern of EEG activation between 3-month-old infants of depressed mothers and infants of nondepressed mothers. In the present study, EEG was recorded in even younger 1-month-old infants of depressed and nondepressed mothers. The infants of depressed mothers exhibited greater relative right frontal EEG asymmetry (due to reduced left frontal activation), and this pattern at 1 month was significantly related to 3-month EEG asymmetry. Right frontal EEG asymmetry was also related to more frequent negative facial expressions (sad and pre-cry faces) during the Brazelton exam. Finally, the infants of depressed mothers showed more indeterminate sleep, were less active, and cried less than infants of nondepressed mothers.

Resting anterior brain electrical activity, self-report measures of Behavioral Approach and Inhibition System (BAS and BIS) strength, and general levels of positive and negative affect (PA and NA) were collected from 46 unselected undergraduates on two separate occasions Electroencephalogram (EEG) measures of prefrontal asymmetry and the self-report measures showed excellent internal consistency reliability and adequate test-retest stability Aggregate measures across the two assessments were computed for all indices Subjects with greater relative left prefrontal activation reported higher levels of BAS strength, whereas those with greater relative right prefrontal activation reported higher levels of BIS strength Prefrontal EEG asymmetry accounted for more than 25% of the variance in the self-report measure of relative BAS-BIS strength Prefrontal EEG, however, was not significantly correlated with PA or NA, or the relative strength of PA versus NA Posterior asymmetry was unrelated to the self-report measures

Two styles of mother-infant interactions have been observed in depressed mothers, including an intrusive style (overstimulating behavior) and a withdrawn style (understimulating behavior). To examine how these styles affect infants, we assessed 87 infants and their mothers, who had been assigned to “intrusive” or “withdrawn” profiles, based on their face-to-face interactive behaviors with their 3-month-old infants. Behavioral assessments were made at 3, 6, and 12 months. The results indicated that infants of withdrawn mothers showed less optimal interactive behavior, greater relative right frontal EEG asymmetry (due to decreased left frontal EEG activation and increased right frontal EEG activation), and lower Bayley Mental Scale scores at 1 year. Infants of intrusive mothers had higher catecholamine and dopamine levels, and their EEG patterns showed greater relative left frontal EEG asymmetry (due to increased left frontal EEG activation and decreased right frontal EEG activation).

Averaged electroencephalogram (EEG) frequency spectra were studied in eight unanesthetized and unmyorelaxed adult male rats with chronically implanted carbon electrodes in symmetrical somesthetic areas when a weak microwave field, amplitude-modulated at extremely low frequency (ELF) was applied. Intermittent field exposure was used. Hemispheric asymmetry in frequency spectra of an ongoing EEG was characterized by a power decrease in the 1.5--3 Hz range on the left hemisphere and by a power decrease in the 10--14 and 20--30 Hz ranges on the right hemisphere. No differences between control and exposure experiments were shown under these routines of data averaging. Significant elevations of EEG asymmetry in 10--14 Hz range were observed during the first 20 s after four from five onsets of the MW field, when averaged spectra were obtained for every 10 s. Under neither control nor pre- and post-exposure conditions was this effect observed. These results are discussed with respect to interaction of MW fields with the EEG generators.

The Behavioral Approach System (BAS) hypersensitivity theory of bipolar disorder (BD; Alloy & Abramson, 2010; Depue & Iacono, 1989) suggests that hyperreactivity in the BAS results in the extreme fluctuations of mood characteristic of BD. In addition to risk conferred by BAS hypersensitivity, cognitive and personality variables may play a role in determining risk. We evaluated relationships among BAS sensitivity, risk taking, and an electrophysiological correlate of approach motivation, relative left-frontal electroencephalography (EEG) asymmetry. BAS sensitivity moderated the relationship between risk taking and EEG asymmetry. More specifically, individuals who were high in BAS sensitivity showed left-frontal EEG asymmetry regardless of their level of risk-taking behavior. However, among individuals who were moderate in BAS sensitivity, risk taking was positively associated with asymmetry. These findings suggest that cognitive and personality correlates of bipolar risk may evidence unique contributions to a neural measure of trait-approach motivation. Clinical implications of these findings are discussed.

We conducted an exploratory study to examine the resting electroencephalography (EEG) correlates of pseudoneglect, a phenomenon wherein neurologically intact individuals show greater attentional bias toward the left side compared with the right side of space. We took the resting EEG of 21 college students for 5 min and then had them complete a computerized line perception task, during which we asked them to judge the midpoint of horizontal lines on the screen. We computed EEG asymmetry measures for theta, alpha, beta, and gamma frequency bands for each of eight locations (right electrode activity-left electrode activity in the analogous location) and separately regressed these onto the degree of pseudoneglect using stepwise multiple regression analyses. We found significant effects for gamma, theta, and beta bands at location F3/4, indicating greater tonic right midfrontal activation in this location. These findings show that individuals with generally greater right midfrontal resting activation across theta, beta, and gamma bands also demonstrate pseudoneglect during a line perception task. These results lend a novel finding to the pseudoneglect literature, namely an individual differences corollary to current active task observations in the field.