Trajectories of resting frontal brain activity and psychopathology in female adolescents exposed to child maltreatment

Resting frontal electroencephalogram (EEG) alpha asymmetry patterns reflecting different affective and motivational tendencies have been proposed as a putative mechanism underlying resilience among maltreated youth. This 2‐year prospective study examined whether developmental stability of resting frontal alpha asymmetry moderated the relation between child maltreatment severity and psychopathology in female adolescents (n = 43; ages 12–16) recruited from child protection agencies. Results identified two trajectories of resting frontal asymmetry: 60.5% displayed stable right and 39.5% displayed stable left frontal alpha asymmetry. Although individuals with these alpha asymmetry profiles experienced comparable childhood trauma severity, adolescents with stable left alpha asymmetry and lower levels of trauma were less likely to present symptoms or an episode of posttraumatic stress disorder (PTSD) and depression over 2 years than those with stable right alpha asymmetry and lower levels of trauma. These findings suggest that developmental patterns of resting left frontal brain activity may buffer against psychopathology in maltreated female youth.     

Frontal asymmetry: A novel biomarker for physical activity and sedentary behavior

Past research has demonstrated that regular physical activity provides a myriad of physical, mental, and emotional benefits. The decision of whether to partake in physical activity (PA) or remain sedentary appears to be partially influenced by motivational and emotional systems. Research suggests left frontal alpha asymmetry is a neural marker of approach motivation. However, studies have not explored whether habitual levels of PA and sedentary behavior relate to this neurophysiological signal. Across two studies, individuals completed measures of habitual PA and sedentary behavior using the International Physical Activity Questionnaire-Short Form. Then, resting electroencephalography activity was recorded. Results of Study 1 (N = 32, 72% women) indicated that more time spent sitting on both weekdays and weekend days were associated with less left frontal asymmetry (r = −.45, p = .027, and r = −.55, p = .005, respectively). Study 2 recruited a larger sample (N = 96, 31% women) and investigated moderators. Greater levels of moderate (r = .27) and total (r = .29) PA were associated with greater left frontal asymmetry (ps < .05), and the relationship between sedentary behavior and less left frontal asymmetry was moderated by sex (weekday: β = .62, p = .011; weekend day: β = .41, p = .034). Our results suggest that left frontal asymmetry may be a novel neurophysiological marker for PA and sedentary behavior.     

The influence of frontal alpha‐asymmetry on the processing of approach‐ and withdrawal‐related stimuli—A multichannel psychophysiology study

The approach‐withdrawal model of hemispheric activation suggests that left frontal cortical areas mediate approach, while right frontal cortical areas mediate withdrawal motivation. Within this framework, the present study investigates the association of frontal cortical asymmetry with attentional and emotional responses toward approach‐ and withdrawal‐related emotional stimuli. Resting frontal asymmetry was measured from 43 students before they passively viewed negative, neutral, and positive emotional pictures. The startle reflex, skin conductance response, and subjective ratings of valence and arousal were assessed to quantify emotional responding, while attention was assessed with ERPs. We also assessed frontal asymmetry in response to the pictures. Results indicated that relatively stronger right frontal cortical activation was associated with increased N1 amplitudes and more negative subjective emotional evaluation of all stimuli. Furthermore, enhanced right frontal asymmetry (state and trait) was associated with diminished emotional modulation of the late positive potential. In contrast, no association of frontal asymmetry with defensive reflex physiology or activation of sympathetic nervous system activity was found. The current data suggest dissociable influence of resting frontal brain asymmetry on attentional and physiological processing of withdrawal‐ and approach‐related stimuli. That is, asymmetrical frontal cortical brain activation might not modulate approach‐/withdrawal‐related motor responses and sympathetic arousal directly, but instead enhances allocation of attentional resources to subjectively significant stimuli. The results are discussed in terms of their potential importance for emotion perception in anxiety disorders and their contribution to the understanding of frontal asymmetry.     

Approach-related left prefrontal EEG asymmetry predicts muted error-related negativity

In two studies, we used electroencephalography (EEG) to test whether approach-motivation-related brain activity would predict reduced sensitivity to negative outcomes. In both studies, participants (Study 1, N=26; Study 2, N=56) were first recorded for baseline EEG to measure approach-related left frontal EEG activity. They then completed either the color-naming Stroop task (Study 1) or the Multi-Source Interference Task (Study 2) to measure error-related negativity (ERN), an event-related potential that has been associated with aversive motivation and distress. In both studies, higher leftward frontal EEG asymmetry predicted reduced ERN amplitude. Hierarchical regression analyses of the separate frontal nodes that comprised the asymmetry score further showed that left frontal activity predicted reduced ERN amplitude whereas right frontal activity predicted greater ERN amplitude. Results have implications for understanding emotion and motivation and for understanding the personal resilience associated with approach motivated states.     

Physical activity does not disturb the measurement of startle and corrugator responses during affective picture viewing

Healthy college females (n=24) completed counterbalanced conditions of 20 min of very low and low intensity cycling exercise and seated rest. Startle and corrugator supercilii responses, and baseline orbicularis oculi and corrugator supercilii electromyographic (EMG) activity, were measured during each exercise condition while participants viewed pleasant, neutral and unpleasant pictures. The exercise conditions did not alter the magnitude of the startle or corrugator responses compared with the resting control condition. Baseline orbicularis EMG increased slightly and baseline corrugator EMG increased significantly, during the low intensity exercise condition. In conclusion, low intensity physical activity is not sufficient to alter emotional responsiveness as assessed by the acoustic startle eyeblink response and corrugator supercilii EMG responses during the viewing of pleasant, neutral, and unpleasant pictures. Despite modestly increased baseline EMG levels, reliable startle and corrugator EMG responses can be obtained in healthy college females during picture viewing while performing low intensity cycling exercise.     

Affective modulation of tactile startle

Two studies were conducted to investigate affective modulation of startle responses to unilateral tactile probes and to determine whether such modulation is lateralized. Right-handed undergraduates received airpuffs to the left or right temple while viewing pleasant, neutral, and unpleasant pictures. Side of probe presentation was varied between the two trial blocks of the experiment in Study 1 (n= 48) but varied randomly within trial blocks in Study 2 (n= 48). Primary results were consistent across studies. Replicating and extending the findings for acoustic probes, eyeblink responses to tactile probes were larger during unpleasant than during pleasant pictures. However, affective modulation of startle did not differ reliably between the two sides of probe presentation (sensory laterality) or the two sides of the response (motor lateralily) in either study or in a combined analysis.     

Psychometric properties of startle and corrugator response in NPU,affective picture viewing,and resting state tasks

The current study provides a comprehensive evaluation of critical psychometric properties of commonly used psychophysiology laboratory tasks/measures within the NIMH RDoC. Participants (N = 128) completed the no‐shock, predictable shock, unpredictable shock (NPU) task, affective picture viewing task, and resting state task at two study visits separated by 1 week. We examined potentiation/modulation scores in NPU (predictable or unpredictable shock vs. no‐shock) and affective picture viewing tasks (pleasant or unpleasant vs. neutral pictures) for startle and corrugator responses with two commonly used quantification methods. We quantified startle potentiation/modulation scores with raw and standardized responses. We quantified corrugator potentiation/modulation in the time and frequency domains. We quantified general startle reactivity in the resting state task as the mean raw startle response during the task. For these three tasks, two measures, and two quantification methods, we evaluated effect size robustness and stability, internal consistency (i.e., split‐half reliability), and 1‐week temporal stability. The psychometric properties of startle potentiation in the NPU task were good, but concerns were noted for corrugator potentiation in this task. Some concerns also were noted for the psychometric properties of both startle and corrugator modulation in the affective picture viewing task, in particular, for pleasant picture modulation. Psychometric properties of general startle reactivity in the resting state task were good. Some salient differences in the psychometric properties of the NPU and affective picture viewing tasks were observed within and across quantification methods.     

Impact of maternal childhood trauma on child behavioral problems: The role of child frontal alpha asymmetry

Childhood trauma is associated with many long-term negative outcomes, and is not limited to the individual experiencing the trauma, but extends to subsequent generations. However, mechanisms underlying the association between maternal childhood trauma and child psychopathology are not well understood. Here, we targeted frontal alpha asymmetry (FAA) as a potential underlying factor of the relationship between maternal childhood trauma and child behavioral problems. Electroencephalography (EEG) was recorded from (N = 45) children (Mean age = 57.9 months, SD = 3.13) during an eyes-closed paradigm in order to evaluate FAA. Mothers reported on their childhood trauma experiences using the Childhood Trauma Questionnaire (CTQ), and on their child's behavior using the child behavior checklist (CBCL). We found that maternal childhood trauma significantly predicted child total, internalizing, and externalizing behavior at age 5 years. We also observed a role for FAA such that it acted as a moderator, but not mediator, for behavioral problems. We found that children with relative more right/less left frontal activity were more at risk to develop behavioral problems when their mother had been exposed to trauma in her childhood. These results indicate that child frontal asymmetry may serve as a susceptibility marker for child behavioral problems.     

Manipulation of frontal EEG asymmetry through biofeedback alters self-reported emotional responses and facial EMG

Individual differences in resting asymmetrical frontal brain activity have been found to predict subsequent emotional responses. The question of whether frontal brain asymmetry can cause emotional responses has yet to be addressed. Biofeedback training designed to alter the asymmetry of frontal brain activity was therefore examined. Eighteen right-handed female participants were randomly assigned to receive biofeedback training designed to increase right frontal alpha relative to left frontal alpha (n = 9) or to receive training in the opposite direction (n = 9). Five consecutive days of biofeedback training provided signals of reward or nonreward depending on whether the difference between right (F4) and left (F3) frontal alpha exceeded a criterion value in the specified direction. Systematic alterations of frontal EEG asymmetry were observed as a function of biofeedback training. Moreover, subsequent self-reported affect and facial muscle activity in response to emotionally evocative film clips were influenced by the direction of biofeedback training.     

The persistence of socially instructed threat: Two threat‐of‐shock studies

Learning to anticipate threat is crucial in guiding protective behavior. In classical conditioning, single trial learning can result in long‐lasting fear associations. To examine whether threat learned through social communication is equally stable, an instructed fear paradigm was used with two repeated sessions on 1 day (Study 1; N = 43) and with separate sessions on 3 consecutive days (Study 2; N = 30). Startle EMG, skin conductance level (SCL), and self‐report data were recorded during alternating periods of instructed threat and safety. Within 1 day, threat‐potentiated startle was present across sessions but threat‐enhanced SCL decreased (Study 1). Across days, threat effects subsided with different timing for startle EMG, SCL, and self‐report (Study 2). The present findings are a laboratory analog for the persistence of socially transmitted fear, which can be amazingly resistant to extinction (e.g., in specific phobias) even in the absence of aversive experiences.     

The temporal dynamics of cognitive reappraisal: Cardiovascular consequences of downregulation of negative emotion and upregulation of positive emotion

This study examines the effects of cognitive reappraisal on the cardiovascular response to affective stimuli. Participants (N = 53) were shown affective images and were asked either to attend to the images, or to downregulate negative affect through reappraisal of negative images or upregulate positive affect through reappraisal of positive images while continuous measures of cardiovascular activity were recorded. Reappraisal of negative images was associated with lower total peripheral resistance and larger cardiac output in the prestimulus period, whereas reappraisal of positive images was associated with less pronounced decreases of heart rate, cardiac output, and mean blood pressure in the viewing period as compared to unregulated conditions. The results indicate that cognitive reappraisal engenders adaptive hemodynamic profiles both during anticipation and during viewing of affective images depending on their valence and the regulatory goal.     

Resting and task‐elicited prefrontal EEG alpha asymmetry in depression: Support for the capability model

The capability model of frontal electroencephalographic (EEG) asymmetry suggests that brain activity during emotional challenge will be a more powerful indicator of predispositions toward psychopathology than activity observed at rest. EEG data were assessed during a resting baseline and a facial emotion task, wherein individuals with (n = 143) and without (n = 163) lifetime major depressive disorder (MDD) made approach (angry and happy) and withdrawal (afraid and sad) facial expressions. EEG asymmetry during emotional challenge was a more powerful indicator of MDD status than resting asymmetry for average, Cz, and linked mastoid references, results in support of the capability model. However, current‐source‐density (CSD) transformed asymmetry was indicative of lifetime MDD status under resting and task‐elicited conditions. Findings suggest that CSD‐transformed data may be more robust indicators of trait frontal EEG asymmetry.     

Emotional & electroencephalographic responses during affective picture viewing after exercise

We examined the effects of 30 min of cycling exercise at a moderate intensity of 50% peak oxygen uptake, compared to 30 min of rest, on changes in emotional responses to pictorial foreground stimuli that reliably elicit unpleasant, neutral, and pleasant affect. Emotional responses were measured by self-reports of valence (unpleasant to pleasant) and arousal (low to high) and by hemispheric asymmetry (R-L) of frontal and parietal brain electroencephalographic (EEG) activity in 13 females and 21 males (24+/-3 y). Compared to after rest, self-reports of arousal in response to unpleasant slides were diminished after exercise, but self-reports of valence and frontal asymmetry of alpha frequencies were generally unchanged. Even so, there were differential responses in asymmetry in the beta frequencies in the frontal region and for alpha and beta frequencies in the parietal region, indicative of decreased activity in the left frontal and right parietal regions after exercise compared to after rest. We conclude that moderately intense cycling exercise generally does not alter emotional responding to pleasant and neutral pictures, but may reduce emotional arousal during exposure to unpleasant stimuli.     

Frontal EEG asymmetry and symptom response to cognitive behavioral therapy in patients with social anxiety disorder

Although previous studies have shown that socially anxious individuals exhibit greater relative right frontal electroencephalogram (EEG) activity at rest, no studies have investigated whether improvements in symptoms as a result of treatment are associated with concomitant changes in resting brain activity. Regional EEG activity was measured at rest in 23 patients with social anxiety disorder (SAD) before and after cognitive behavioral therapy (CBT). Results indicated that patients shifted significantly from greater relative right to greater relative left resting frontal brain activity from pre- to posttreatment. Greater left frontal EEG activity at pretreatment predicted greater reduction in social anxiety from pre- to posttreatment and lower posttreatment social anxiety after accounting for pretreatment symptoms. These relations were specific to the frontal alpha EEG asymmetry metric. These preliminary findings suggest that resting frontal EEG asymmetry may be a predictor of symptom change and endstate functioning in SAD patients who undergo efficacious psychological treatment.     

Frontal EEG asymmetry and sensation seeking in young adults

Sensation seeking has been characterized as a desire to seek novel, intense sensations, and the willingness to take risks in pursuing them. In two separate studies of young adults, we examined the relation between measures of sensation seeking and the pattern of resting frontal EEG asymmetry, thought to reflect a biological predisposition to approach new experiences. As predicted, high sensation seeking was related to a greater relative left frontal activity at rest in both studies, which may be specific to men. How greater relative left frontal cortical activity at rest is related to a tendency to engage in sensation-seeking and risky behaviors is discussed.     

The startle response: Developmental effects and a paradigm for children and adults

A film paradigm was developed to examine baseline and emotion modulated startle across a broad age range from preschool to adulthood. The paradigm was tested in children (3‐, 5‐, 7‐, and 9‐year‐olds) and adults (total N = 122). The paradigm elicited a similar startle potentiation pattern across age groups; however, baseline startle changed with age: 3‐ and 5‐year‐olds showed lower response probability and magnitude of baseline startle than adults. Females exhibited larger baseline startle response probability and overall magnitude than did males; however, no sex by emotion modulated startle interaction was noted. Anxiety measures were obtained for all children. Individual differences in anxiety were associated with baseline startle magnitude among older but not younger children. No association of anxiety with startle potentiation was noted. Overall the film paradigm was applicable across a wide developmental span, revealing potential developmental and gender differences in baseline startle magnitude and response probability. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 52: 78–89, 2010     

Frontal brain asymmetry and immune function.

The relation between brain activity and the immune system was evaluated by assessing immune responses in 20 healthy women who manifested extreme differences in the asymmetry of frontal cortex activation. One group showed extreme and stable left frontal activation; the other group showed extreme and stable right frontal activation. As predicted, women with extreme right frontal activation had significantly lower levels of natural killer cell activity (at effector:target cell ratios of 33:1 and 11:1) than did left frontally activated individuals. This difference did not extend to two other immune measures, lymphocyte proliferation and T-cell subsets. However, higher immunoglobulin levels of the M class were observed in the right frontal group. In this study, the immune patterns could not be accounted for by plasma cortisol levels, anxiety- and depression-related symptomatology, or recent health histories. These findings support the hypothesis that there is a specific association between frontal brain asymmetry and certain immune responses.     

Cognitive and social processes predicting partner psychological adaptation to early stage breast cancer

Introduction. The diagnosis and subsequent treatment for early stage breast cancer is stressful for partners. Little is known about the role of cognitive and social processes predicting the longitudinal course of partners' psychosocial adaptation. This study evaluated the role of cognitive and social processing in partner psychological adaptation to early stage breast cancer, evaluating both main and moderator effect models. Moderating effects for meaning making, acceptance, and positive reappraisal on the predictive association of searching for meaning, emotional processing, and emotional expression on partner psychological distress were examined. Materials and methods. Partners of women diagnosed with early stage breast cancer were evaluated shortly after the ill partner's diagnosis (N=253), 9 (N=167), and 18 months (N=149) later. Partners completed measures of emotional expression, emotional processing, acceptance, meaning making, and general and cancer‐specific distress at all time points. Results. Lower satisfaction with partner support predicted greater global distress, and greater use of positive reappraisal was associated with greater distress. The predicted moderator effects for found meaning on the associations between the search for meaning and cancer‐specific distress were found and similar moderating effects for positive reappraisal on the associations between emotional expression and global distress and for acceptance on the association between emotional processing and cancer‐specific distress were found. Conclusions. Results indicate several cognitive–social processes directly predict partner distress. However, moderator effect models in which the effects of partners' processing depends upon whether these efforts result in changes in perceptions of the cancer experience may add to the understanding of partners' adaptation to cancer.     

Learning to fear suffocation: a new paradigm for interoceptive fear conditioning

The present study aimed to establish a new interoceptive fear conditioning paradigm. The conditioned stimulus (CS) was a flow resistor that slightly obstructs breathing; the unconditional stimulus (US) was a breathing occlusion. The paired group (N = 21) received 6 acquisition trials with paired CS–US presentations. The unpaired group (N = 19) received 6 trials of unpaired CS–US presentations. In the extinction phase, both groups were administered 6 CS‐only trials. Measurements included startle eyeblink response, electrodermal responses, and self‐reported US expectancy. In the paired group, startle blink responses were larger during CS compared to intertrial interval during acquisition and extinction. Electrodermal and US expectancies were larger for the paired than for the unpaired group during acquisition, but not during extinction. The present paradigm successfully established interoceptive fear conditioning with panic‐relevant stimuli.     

Regional brain activity and strenuous exercise: predicting affective responses using EEG asymmetry

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.