Sarah M. Buck

Aerobic Fitness and Cognitive Development: Event-Related Brain Potential and Task Performance Indices of Executive Control in Preadolescent Children

The relationship between aerobic fitness and executive control was assessed in 38 higher- and lower-fit children (M-sub(age) = 9.4 years), grouped according to their performance on a field test of aerobic capacity. Participants performed a flanker task requiring variable amounts of executive control while event-related brain potential responses and task performance were assessed. Results indicated that higher-fit children performed more accurately across conditions of the flanker task and following commission errors when compared to lower-fit children, whereas no group differences were observed for reaction time. Neuroelectric data indicated that P3 amplitude was larger for higher- compared to lower-fit children across conditions of the flanker task, and higher-fit children exhibited reduced error-related negativity amplitude and increased error positivity amplitude compared to lower-fit children. The data suggest that fitness is associated with better cognitive performance on an executive control task through increased cognitive control, resulting in greater allocation of attentional resources during stimulus encoding and a subsequent reduction in conflict during response selection. The findings differ from those observed in adult populations by indicating a general rather than a selective relationship between aerobic fitness and cognition.

Aerobic Fitness and Executive Control of Relational Memory in Preadolescent Children

PURPOSE the neurocognitive benefits of an active lifestyle in childhood have public health and educational implications, especially as children in todays technological society are becoming increasingly overweight, unhealthy, and unfit. Human and animal studies show that aerobic exercise affects both prefrontal executive control and hippocampal function. This investigation attempts to bridge these research threads by using a cognitive task to examine the relationship between aerobic fitness and executive control of relational memory in preadolescent 9- and 10-yr-old children. METHOD higher-fit and lower-fit children studied faces and houses under individual item (i.e., nonrelational) and relational encoding conditions, and the children were subsequently tested with recognition memory trials consisting of previously studied pairs and pairs of completely new items. With each subject participating in both item and relational encoding conditions, and with recognition test trials amenable to the use of both item and relational memory cues, this task afforded a challenge to the flexible use of memory, specifically in the use of appropriate encoding and retrieval strategies. Hence, the task provided a test of both executive control and memory processes. RESULTS lower-fit children showed poorer recognition memory performance than higher-fit children, selectively in the relational encoding condition. No association between aerobic fitness and recognition performance was found for faces and houses studied as individual items (i.e., nonrelationally). CONCLUSIONS the findings implicate childhood aerobic fitness as a factor in the ability to use effective encoding and retrieval executive control processes for relational memory material and, possibly, in the strategic engagement of prefrontal- and hippocampal-dependent systems.

Self-Efficacy Effects on Neuroelectric and Behavioral Indices of Action Monitoring in Older Adults

The relationships between self-efficacy (SE), i.e., beliefs in personal capabilities, and behavioral and neuroelectric (i.e., ERN, Pe) indices of action monitoring were investigated in 40 older adults (13 male) during the completion of a flanker paradigm performed under task conditions emphasizing either accuracy or speed. SE relative to task performance during both conditions was assessed prior to each cognitive task. Results indicated that high-SE older adults exhibited larger ERN and Pe amplitudes compared to low-SE older adults under the accuracy instruction condition. Additionally, a moderating effect of SE on the relationship between ERN and post-error response accuracy was revealed in the accuracy condition, with greater ERN amplitude associated with greater post-error accuracy in the high-SE group. No significant relationships were evident between ERN and post-error accuracy in the low-SE group. Further, no significant relationships involving SE were observed in the speed condition. The findings suggest that SE may be related to neuroelectric and behavioral indices of action monitoring in older adults when task demands require greater attention to action monitoring processes.

Emotional responses to pictures of oneself in healthy college age females

Emotional responses related to self-perceptions were investigated in healthy college-aged females using a picture-viewing paradigm that consisted of four categories of pictures (pleasant, neutral, unpleasant, and full body pictures of themselves). The startle eye-blink reflex, facial EMG, and self-reported valence, arousal, and dominance measures were recorded for each picture. Startle reflex and facial EMG measures exhibited decreased activation for self-pictures compared to the other affective categories. Self-reports indicated self-pictures were rated as moderately pleasant, low arousing, and moderately dominant relative to the other affective picture categories. The findings of reduced startle blink reflex coupled with decreased activation for all facial EMG measures and the moderate self-report ratings suggest increased attentional processing for self-pictures. These findings provide an understanding of emotional responses to self-perceptions in healthy young females.