Andrew C. Parks

Single bouts of exercise selectively sustain attentional processes

This study examined how single bouts of exercise may differentially modulate neuroelectric correlates of attentional orienting and processing. Using a within-participants design, ERPs and task performance were assessed in response to a perceptually challenging three-stimulus oddball task prior to and following a bout of exercise or seated rest during two separate, counterbalanced sessions. Findings revealed that, following a single bout of exercise, attentional processing was sustained relative to pretest whereas prolonged sitting resulted in attentional decrements. Focal attention resulting from attentional orienting, in contrast, does not appear to be sensitive to the influences of single bouts of physical activity. These findings suggest that acute exercise-induced changes in cognition do not originate from an overall modulation of attention but instead are specific to aspects of attentional processing.

Muscular and Aerobic Fitness, Working Memory, and Academic Achievement in Children

Purpose This study investigated the relationship between aerobic and muscular fitness with working memory and academic achievement in preadolescent children. Methods Seventy-nine 9- to 11-yr-old children completed an aerobic fitness assessment using a graded exercise test; a muscular fitness assessment consisting of upper body, lower body, and core exercises; a serial n-back task to assess working memory; and an academic achievement test of mathematics and reading. Results Hierarchical regression analyses indicated that after controlling for demographic variables (age, sex, grade, IQ, socioeconomic status), aerobic fitness was associated with greater response accuracy and d′ in the 2-back condition and increased mathematic performance in algebraic functions. Muscular fitness was associated with increased response accuracy and d′, and longer reaction time in the 2-back condition. Further, the associations of muscular fitness with response accuracy and d′ in the 2-back condition were independent of aerobic fitness. Conclusion The current findings suggest the differential relationships between the aerobic and the muscular aspects of physical fitness with working memory and academic achievement. With the majority of research focusing on childhood health benefits of aerobic fitness, this study suggests the importance of muscular fitness to cognitive health during preadolescence.

The association between a history of concussion and variability in behavioral and neuroelectric indices of cognition

Associations between a history of concussion and variability in behavioral and neuroelectric indices of cognition were assessed in college-aged adults with a history of concussion and a healthy control group, in response to a stimulus discrimination task and a more attentionally demanding flanker task. Greater intra-individual variability was observed only for behavioral indices of reaction time in response to the flanker task for those with a history of concussion. An association was also observed between the number of concussions resulting in a loss of consciousness and greater variability of reaction time regardless of the type of task. Relative to neuroelectric measures, a concussive history was associated with smaller P3 amplitude only in response to the flanker task; with no differences between groups observed in response to the oddball task or for intra-individual variability measures. Thus, increased variability associated with a history of concussion appears to be behavior and process specific. The behavioral metrics and functions assessed are important considerations for identifying subtle, yet persistent influences of concussion on cognitive performance. Further, factors such as loss of consciousness associated with a concussive injury may moderate the extent to which these increases in behavioral variability manifest. Thus, the identification of persistent cognitive impairment following concussive injuries necessitates the utilization of appropriate tasks and may be facilitated by going beyond behavioral measures of central tendency.

The Association between Physical Activity During the Day and Long-Term Memory Stability

Despite positive associations between chronic physical activity and memory; we have little understanding of how best to incorporate physical activity during the day to facilitate the consolidation of information into memory, nor even how time spent physically active during the day relates to memory processes. The purpose of this investigation was to examine the relation between physical activity during the day and long-term memory. Ninety-two young adults learned a list of paired-associate items and were tested on the items after a 12-hour interval during which heart rate was recorded continuously. Although the percentage of time spent active during the day was unrelated to memory, two critical physical activity periods were identified as relating to the maintenance of long-term memory. Engaging in physical activity during the period 1 to 2-hours following the encoding of information was observed to be detrimental to the maintenance of information in long-term memory. In contrast, physical activity during the period 1-hour prior to memory retrieval was associated with superior memory performance, likely due to enhanced retrieval processing. These findings provide initial evidence to suggest that long-term memory may be enhanced by more carefully attending to the relative timing of physical activity incorporated during the day.

VI. THE ROLE OF PHYSICAL ACTIVITY IN REDUCING BARRIERS TO LEARNING IN CHILDREN WITH DEVELOPMENTAL DISORDERS

Emerging research suggests that physical activity may be an effective non-pharmaceutical intervention approach for childhood developmental disorders. Findings indicate that both single bouts of activity and chronic physical activity associate with improved mental health and classroom performance in children with attention-deficit/hyperactivity disorder and children with autism spectrum disorders. This review describes the research in this area and identifies limitations and challenges to the translation of these findings to promote physical activity in clinical practice and educational policy.

Variability of ICA decomposition may impact EEG signals when used to remove eyeblink artifacts

Despite the growing use of independent component analysis (ICA) algorithms for isolating and removing eyeblink-related activity from EEG data, we have limited understanding of how variability associated with ICA uncertainty may be influencing the reconstructed EEG signal after removing the eyeblink artifact components. To characterize the magnitude of this ICA uncertainty and to understand the extent to which it may influence findings within ERP and EEG investigations, ICA decompositions of EEG data from 32 college-aged young adults were repeated 30 times for three popular ICA algorithms. Following each decomposition, eyeblink components were identified and removed. The remaining components were back-projected, and the resulting clean EEG data were further used to analyze ERPs. Findings revealed that ICA uncertainty results in variation in P3 amplitude as well as variation across all EEG sampling points, but differs across ICA algorithms as a function of the spatial location of the EEG channel. This investigation highlights the potential of ICA uncertainty to introduce additional sources of variance when the data are back-projected without artifact components. Careful selection of ICA algorithms and parameters can reduce the extent to which ICA uncertainty may introduce an additional source of variance within ERP/EEG studies.

A primer on investigating the after effects of acute bouts of physical activity on cognition

&NA; An emerging body of evidence has begun to document the beneficial after effects of single bouts — or doses — of physical activity for cognition. This article highlights a selection of common themes and critical delimitations that investigators new to this area of research as well as those currently working in the field may find relevant for advancing research in this area. The intent of this article is to provide a stimulus for future investigations to enhance not only the breadth and depth of the evidence, but also the experimental rigor. In doing so, a number of fundamental considerations are discussed including the aspects of cognition predominantly focused upon to date, issues related to the dose of the physical activity (i.e., how long the after effects persist, what characteristics of the dose may maximize the cognitive after effects), potential moderating variables, as well as potential underlying mechanisms. Additionally, discussion is provided regarding methodological considerations for future investigations including implications of the experimental design, control conditions, and cognitive assessment utilized, as well as statistical and reporting considerations to facilitate transparency. By calling attention to these areas, the hope is that future research may advance our understanding of the underlying mechanisms, theoretical development, and clinical relevance of the cognitive after effects of these single doses of physical activity.

Preliminary evidence for differential trajectories of recovery for cognitive flexibility following sports-related concussion.

Objective: A critical barrier to the understanding of disruptions to cognitive flexibility following sports-related concussion is the use of assessments that conflate shifts of visuospatial attention and contextual rules. Because these dissociable forms of cognitive flexibility are subserved by distinct neural networks, the utility of a cognitive flexibility assessment following concussion may be reduced, depending upon the extent to which the task requires shifting visuospatial attention relative to shifting contextual rules. Accordingly, the current investigation examined the extent to which these aspects of cognitive flexibility exhibit differential trajectories of recovery following a sports-related concussion. Method: Twenty-two athletes with sports-related concussions were assessed on a cognitive flexibility task with 2 switch conditions (i.e., perceptual-based and contextual rule−based) within 72 hr of injury, after return to play, and within 1 month following return to play. Thirty-three healthy control athletes were tested at the same intervals. Results: Findings revealed that concussed athletes demonstrated protracted disruptions in task performance on a visuospatial attention−based cognitive flexibility task relative to healthy controls, whereas disruptions in task performance on a contextual rule−based cognitive flexibility task resolved after the acute phase of injury. These findings suggest that dissociable forms of cognitive flexibility exhibit differential trajectories of recovery. Conclusions: Therefore, evaluations detecting sports-related concussion disruptions in cognitive flexibility may be reduced depending on the extent to which they rely on contextual rule−based decisions. Test batteries focusing on visuospatial attention−based demands may be useful additions to aid in the objective assessment and follow-up management of athletes following the acute phase of injury.