Diane L. Santesso

Electrophysiological Changes during Adolescence: A Review.

While psychological research has long shown that adolescence is a period of major cognitive and affective transition, recent neurophysiological research has shown that adolescence is also accompanied by observable maturational changes in the brain, both in terms of structure and neurotransmitter function. Given this situation, we would expect that there should be observable and perhaps major changes in electrocortical activity and responses. In this review, we discuss developmental reductions in EEG power and alterations in the dominant band of EEG oscillation frequency, moderated by developmental factors such as growth-related changes in grey and white matter, and in the developmental history of cognitive and sociocultural stressors. Similarly, we summarize alterations in event-related potential components reflecting stimulus processing, response monitoring, and response anticipation. We review the literature on such changes in EEG and event-related potentials during the adolescent period and summarize some of the new developments in the field as well as interpretative difficulties.

Error-related electrocortical responses are enhanced in children with obsessive-compulsive behaviors.

The error-related negativity (ERN or Ne) and positivity (Pe) are event-related potential components elicited during simple discrimination tasks after an error response. The ERN and Pe have a fronto-central scalp distribution and may be an indirect measure of anterior cingulate (AC) activity as it relates to performance monitoring. Brain imaging studies suggest that obsessive–compulsive disorder (OCD) is associated with exaggerated activity of the AC while electrophysiological studies have found an association between OCD and pronounced ERNs in adults. The present study explored the relation between obsessive–compulsive behaviors, the ERN, and the Pe in a sample of nonclinical 10-year-old children. It was found that more parent-reported obsessive–compulsive behaviors were associated with larger ERN and Pe components in the children. Results suggest unique contributions of the ERN and Pe in predicting obsessive–compulsive behaviors.

Retest reliability of medial frontal negativities during performance monitoring.

The error-related negativity (ERN) and feedback-related negativity (FRN) have been used as electrophysiological indices of performance monitoring produced in response to internally generated (errors) and externally generated (feedback) activations of the anterior cingulate cortex (ACC). No studies to date have systematically examined the measurement reliability of these components. In this article, we present the retest reliability of the ERN and FRN during response tasks designed to elicit errors or feedback responses on two occasions. Data from four experiments are presented in which participants performed tasks over various periods of time. Results indicate good retest reliability of the ERN and FRN amplitudes and source generation of these components. The present article provides important validation of the ERN and FRN as stable and trait-like electrophysiological reflections of performance monitoring and ACC functional integrity.

ERP correlates of error monitoring in 10-year olds are related to socialization.

Research suggests that the anterior cingulate cortex (ACC) generates the error-related negativity (ERN or Ne), an event-related potential component that reflects response monitoring and is influenced by individual differences in personality. The present study examined the relation between personality as indexed by the Junior Eysenck Personality Questionnaire (Extraversion, Neuroticism, Psychoticism, and Lie scale) and the ERN in 10-year-old children. High scores on the Psychoticism and low scores on the Lie scale, which are taken to reflect low socialization in children, were associated with smaller ERNs. Results lend support to previous studies finding this association in adults. We argue that the ERN may be an indirect measure of ACC activity and is affected by ones concern with task performance. The results of the present study extend findings previously reported in adults to a population of normally developing children and show that similar mechanisms of performance monitoring may underlie individual differences in personality across development.

Age, sex and individual differences in punishment sensitivity: Factors influencing the feedback-related negativity

The anterior cingulate cortex (ACC) is central to evaluating performance outcomes and has been linked to individual differences in affective responses to feedback. We used electrophysiological source localization to examine the feedback-related negativity (FRN) and related ACC activity during a gambling task in relation to punishment and reward sensitivity among 16- to 17-year-old adolescents (n=20) and 18- to 29-year-old adults (n=30). The FRN was larger for monetary loss compared to win feedback and larger for high relative to low monetary value feedback, with no age differences in the FRN for win or loss feedback. Self-reported sensitivity to punishment accounted for unique variance (over sex and sensitivity to reward) in FRNs, with higher scores relating to larger FRNs and increased rostral ACC activity. These results support the ACC role in experiencing negative performance feedback, especially for individuals highly sensitive to punishment.

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.

Adolescent peer interaction and trait surgency weaken medial prefrontal cortex responses to failure

Adolescent risk taking has been known to increase in the presence of peers. We hypothesized that peer interaction reduces the activation of the medial prefrontal cortex (mPFC) that is required for self-regulation of reward-driven behavior. We also expected that mPFC activity would be reduced more in those with greater surgency, a composite trait of behavioral approach, sensation seeking and positive affect. In our study, 20 15-year-old boys played a simulated driving video game alone and in the presence of peers who were encouraged to call out advice while we recorded the feedback-related negativity (FRN) event-related potential in response to an impending car crash. FRN amplitude was reduced both as a function of peer presence and increased surgency. More importantly, we also calculated intracerebral current source density at the time of the FRNs, and found that both greater surgency and peer presence are associated with reduced activity specifically in the mPFC. Riskier performance resulting in more car crashes resulted from the presence of peers only as an interaction with surgency, this interaction being related strongly to reduced activity in the ventromedial PFC.

Autonomic predictors of Stroop performance in young and middle-aged adults.

Although changes in autonomic activity have been extensively examined as responses to cognitive challenges, relatively few studies have used individual differences in autonomic parameters to predict executive performance in healthy adults. Here we examined baseline and task-related changes in heart rate and heart rate variability (measured by respiratory sinus arrhythmia (RSA)) to predict performance of a pictorial Stroop task in a group of 81 healthy adults aged 17-55. Greater autonomic reactivity (increased heart rate and reduced RSA for task performance) was associated with faster colour naming of faces in the Stroop task. Dividing the group by median age revealed that middle-aged adults reduced RSA to a greater degree than their younger counterparts in the context of equivalent performance across groups. Findings suggest that performance of executive function tasks that evoke attentional control may depend in part on the responsiveness of autonomic control parameters via age-dependent mechanisms.

Changes in EEG Cross-Frequency Coupling During Cognitive Behavioral Therapy for Social Anxiety Disorder

Coupling between EEG delta and beta oscillations is enhanced among anxious and healthy individuals during anticipatory anxiety. EEG coupling patterns associated with psychotherapy have not yet been quantified in socially anxious individuals. In this study, we used a double baseline, repeated measures design, in which 25 adults with a principal diagnosis of social anxiety disorder completed 12 weekly sessions of standardized group cognitive behavioral therapy and four EEG assessments: two at pretreatment, one at midtreatment, and one at posttreatment. Treatment was associated with reductions in symptom severity across multiple measures and informants, as well as reductions in delta-beta coupling at rest and during speech anticipation. Moreover, the clinical group exhibited greater coupling at pretreatment than did post hoc control participants with low social anxiety. The EEG cross-frequency profiles in the clinical group normalized by the posttreatment assessment. These findings provide evidence of concomitant improvement in neural and behavioral functioning among socially anxious adults undergoing psychotherapy.

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.