Karen J. Mathewson

Brain bases of error-related ERPs as influenced by age and task

Age effects in the error negativity (Ne) and error positivity (Pe) were examined in a standard letter flanker task and an age-sensitive source memory exclusion task. Older adults made more errors and produced Ne and Pe components of lower amplitude in both tasks. The Ne was insensitive to task and error rate. The Pe, however, was reduced in the source memory relative to the flanker task and was correlated with error rate in both tasks. Ne and Pe dipoles were generally localized to anterior cingulate cortex, but dipoles associated with the Pe were more frontal for flanker errors and, for young adults, more posterior for source errors. These data suggest that the Ne reflects an automatic response to error as it occurs whereas the Pe, being more sensitive to age and task demands, and more closely linked to accuracy, reflects the allocation of attention to an error that has been made.

Capturing and holding attention: The impact of emotional words in rapid serial visual presentation

When two masked, to-be-attended targets are presented within approximately 500 msec of each other, accurate report of the second target (T2) suffers more than when targets are presented farther apart in time—an attentional blink (AB). In the present study, the AB was found to be larger when taboo words were presented as a first target (T1), as compared with the AB found when emotionally neutral, negative, or positive words were presented as T1, suggesting that taboo words received preferential attentional processing. Comparable results were also obtained when taboo words were presented as to-be-ignored distractors in single-target rapid serial visual presentation (RSVP). Arousal, but not valence, ratings of the emotional words predicted accuracy on subsequent targets in both dual- and single-task RSVP. Recognition memory for taboo words accounted fully for the negative relationships between arousal ratings and accuracy on subsequent targets, suggesting that arousal-triggered changes in attentional allocation influenced encoding of taboo words at the time they were encountered.

Regional EEG alpha power, coherence, and behavioral symptomatology in autism spectrum disorder

OBJECTIVE Although distinct patterns of resting brain electrical activity (EEG) and functional connectivity are believed to distinguish individuals with autism spectrum disorders (ASD) from their unimpaired peers, researchers have only recently begun to link patterns of brain activity and connectivity to behavior in ASD. METHOD We examined regional eyes-closed and eyes-open EEG alpha power and coherence at rest in relation to self-reported perceptual and social behavior in 15 adults diagnosed with ASD and a matched comparison group of 16 unimpaired adults. RESULTS The groups did not differ on eyes-closed EEG alpha power or coherence, but adults with ASD showed less alpha suppression for the eyes-open condition than did controls. In the ASD group, preferential attention to detail (perceptual domain) was associated with lower levels of alpha activity and reduced coherence in posterior regions. No relations between social interaction difficulties (social domain) and alpha measures were found for either group alone. CONCLUSIONS These relations suggest that the processing of perceptual details may be carried out by relatively less synchronized neuronal units in adults with ASD, and may be relatively automatic. SIGNIFICANCE Findings are discussed in relation to recent models of narrow minicolumnar brain structure and reduced functional neural connectivity in ASD.

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.

Aging and electrocortical response to error feedback during a spatial learning task

Event-related potentials were collected as older and younger adults responded to error feedback in an adaptation of the Groton Maze Learning Test, an age-sensitive measure of spatial learning and executive skills expected to maximally involve anterior cingulate cortex (ACC). Older adults made more errors and produced smaller feedback-related negativities (FRNs) than young controls. LORETA source localization revealed that, for young adults, neural activation associated with the FRN was focused in ACC and was stronger to negative feedback. Older adults responded with less intense and less differentiated ACC activation, but FRN amplitudes did relate to error rate for the most difficult mazes. The feedback P3 was sensitive to negative feedback but played no role in the prediction of error for either group. These data reflect the selective age-related decline of ACC response but also its continued contribution to performance monitoring in aging.

Autonomic and electrophysiological correlates of emotional intensity in older and younger adults.

Anterior cingulate cortex (ACC) is involved in the modulation of autonomic activity, emotional responsivity, and the monitoring of goal-directed behavior. However, these functions are rarely studied together to determine how they relate or whether their pattern of relation changes with age. We recorded respiratory sinus arrhythmia (RSA), an index of autonomic activity, error-related event related potentials (ERN/Pe), generated in ACC, and the self-reported intensity of 5 basic emotions in older and younger adults. Emotional intensity did not differ with age. The ERN/Pe and RSA were reduced with age and related specifically to sadness intensity for both groups. When examined together, RSA accounted for the relation between ERN/Pe and sadness. This is consistent with a model of medial prefrontal function in which autonomic processes mediate the relation between cognitive control and affective regulation, a pattern that also did not differ with age.

An event-related source localization study of response monitoring and social impairments in autism spectrum disorder.

A number of studies suggest anterior cingulate cortex (ACC) abnormalities in autism spectrum disorder (ASD), which might underlie response monitoring and social impairments exhibited by children and adolescents with ASD. The goal of the present study was to extend this work by examining error and correct response monitoring using event-related potentials (ERN, Pe, CRN) and LORETA source localization in high functioning adults with ASD and controls. Adults with ASD showed reduced ERN and Pe amplitudes and reduced rostral ACC activation compared with controls. Adults with ASD also showed less differentiation between error and correct ERP components. Social impairments and higher overall autism symptoms were related to reduced rostral ACC activity at the time of the ERN, particularly in adults with ASD. These findings suggest that reduced ACC activity may reflect a putative brain mechanism involved in the origins and maintenance of social impairments and raise the possibility of the presence of stable brain-behavior relation impairment across development in some individuals with ASD.

Mental Health of Extremely Low Birth Weight Survivors: A Systematic Review and Meta-Analysis.

Although individuals born at extremely low birth weight (ELBW; < 1,000 g) are the most vulnerable of all preterm survivors, their risk for mental health problems across the life span has not been systematically reviewed. The primary objective of this systematic review and meta-analysis was to ascertain whether the risk for mental health problems is greater for ELBW survivors than their normal birth weight (NBW) peers in childhood, adolescence, and adulthood. Forty-one studies assessing 2,712 ELBW children, adolescents, and adults and 11,127 NBW controls were reviewed. Group differences in mental health outcomes were assessed using random effects meta-analyses. The impacts of birthplace, birth era, and neurosensory impairment on mental health outcomes were assessed in subgroup analyses. Children born at ELBW were reported by parents and teachers to be at significantly greater risk than NBW controls for inattention and hyperactivity, internalizing, and externalizing symptoms. ELBW children were also at greater risk for conduct and oppositional disorders, autistic symptoms, and social difficulties. Risks for parent-reported inattention and hyperactivity, internalizing, and social problems were greater in adolescents born at ELBW. In contrast, ELBW teens self-reported lower inattention, hyperactivity, and oppositional behavior levels than their NBW peers. Depression, anxiety, and social difficulties were elevated in ELBW survivors in adulthood. Group differences were robust to region of birth, era of birth, and the presence of neurosensory impairments. The complex needs faced by children born at ELBW continue throughout development, with long-term consequences for psychological and social well-being.

Test–retest reliability of regional electroencephalogram (EEG) and cardiovascular measures in social anxiety disorder (SAD)

Although the search for psychophysiological manifestations of social anxiety has a rich history, there appear to be no published reports examining the reliability of continuous electrocortical measures that putatively index stress vulnerability and stress reactivity in socially anxious individuals. We examined the 1-week test-retest reliability of regional electroencephalogram (EEG) alpha asymmetry and power, respiratory sinus arrhythmia (RSA), heart period, and heart period variability measures at rest and during anticipation of an impromptu speech in 26 adults diagnosed with social anxiety disorder (SAD). Across the 1-week time period, we found medium-to-large correlations for regional EEG asymmetry and large correlations for regional EEG alpha power, RSA, heart period, and heart period variability measures at rest and during speech anticipation, before and after accounting for age and medication status. These results are similar to patterns observed in nonclinical samples and appear to provide the first documented evidence of test-retest reliability of psychophysiological measures that index central nervous system activity in socially anxious individuals. These findings also provide support for the notion that resting frontal EEG asymmetry and RSA constitute relatively stable individual differences in this clinical population.

Does respiratory sinus arrhythmia (RSA) predict anxiety reduction during cognitive behavioral therapy (CBT) for social anxiety disorder (SAD)

Modifying dysfunctional emotion regulation is an important goal in psychological treatments for social anxiety disorder (SAD). Antecedent-focused strategies learned in cognitive behavioral therapy (CBT), such as cognitive reappraisal, have proven more effective in reducing social anxiety than response-focused strategies, such as expressive suppression. Still, not all patients with SAD respond well to CBT. Medications and physiological factors may also influence the clinical response. The purpose of the present study was to examine the role that these factors play in determining treatment response following CBT for SAD. Using multilevel modeling, we examined associations across four separate laboratory visits between change in self-reported anxiety and indices of reappraisal, suppression, medication status, and resting respiratory sinus arrhythmia (RSA), a proxy measure of self-regulatory capacity, in 23 socially anxious adults during a 12-week program of CBT. Most participants were ultimately classified as responders to CBT (n=15), but in some, anxiety levels remained unchanged (n=8). Medication use explained substantial variance related to individual differences in anxiety among participants. When modeled separately, reappraisal, suppression, and RSA each accounted for significant variance related to anxiety. However, the best-fitting model included reappraisal and RSA. Moreover, RSA reactivity (change in RSA levels over time) was more important for predicting anxiety reduction than were baseline levels of RSA. These findings suggest that reappraisal and parasympathetic responsiveness may be important in reducing anxiety in adults with SAD who respond well to CBT.