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.

Effects of the FITKids randomized controlled trial on executive control and brain function

OBJECTIVE

To assess the effect of a physical activity (PA) intervention on brain and behavioral indices of executive control in preadolescent children.

METHODS

Two hundred twenty-one children (7-9 years) were randomly assigned to a 9-month afterschool PA program or a wait-list control. In addition to changes in fitness (maximal oxygen consumption), electrical activity in the brain (P3-ERP) and behavioral measures (accuracy, reaction time) of executive control were collected by using tasks that modulated attentional inhibition and cognitive flexibility.

RESULTS

Fitness improved more among intervention participants from pretest to posttest compared with the wait-list control (1.3 mL/kg per minute, 95% confidence interval [CI]: 0.3 to 2.4; d = 0.34 for group difference in pre-to-post change score). Intervention participants exhibited greater improvements from pretest to posttest in inhibition (3.2%, 95% CI: 0.0 to 6.5; d = 0.27) and cognitive flexibility (4.8%, 95% CI: 1.1 to 8.4; d = 0.35 for group difference in pre-to-post change score) compared with control. Only the intervention group increased attentional resources from pretest to posttest during tasks requiring increased inhibition (1.4 µV, 95% CI: 0.3 to 2.6; d = 0.34) and cognitive flexibility (1.5 µV, 95% CI: 0.6 to 2.5; d = 0.43). Finally, improvements in brain function on the inhibition task (r = 0.22) and performance on the flexibility task correlated with intervention attendance (r = 0.24).

CONCLUSIONS

The intervention enhanced cognitive performance and brain function during tasks requiring greater executive control. These findings demonstrate a causal effect of a PA program on executive control, and provide support for PA for improving childhood cognition and brain health.

The negative association of childhood obesity to cognitive control of action monitoring

The global epidemic of childhood obesity has become a major public health concern. Yet, evidence regarding the association between childhood obesity and cognitive health has remained scarce. This study examined the relationship between obesity and cognitive control using neuroelectric and behavioral measures of action monitoring in preadolescent children. Healthy weight and obese children performed compatible and incompatible stimulus-response conditions of a modified flanker task, while task performance and the error-related negativity (ERN) were assessed. Analyses revealed that obese children exhibited a longer reaction time (RT) relative to healthy weight children for the incompatible condition, whereas no such difference was observed for the compatible condition. Further, obese children had smaller ERN amplitude relative to healthy weight children with lower post-error response accuracy. In addition, healthy weight children maintained post-error response accuracy between the compatible and incompatible conditions with decreased ERN amplitude in the incompatible condition, whereas obese children exhibited lower post-error response accuracy for the incompatible relative to the compatible condition with no change in ERN amplitude between the compatibility conditions. These results suggest that childhood obesity is associated with a decreased ability to modulate the cognitive control network, involving the prefrontal cortex and anterior cingulate cortex, which supports action monitoring.

Physical activity and trial-by-trial adjustments of response conflict

The relationship of physical activity to trial-by-trial adjustments of response conflict was assessed using behavioral task performance, the N2 event-related brain potential component, and phase-locking values (PLVs) in a lower gamma band during a perceptual conflict task. Nineteen physically active and 19 inactive young adults (mean age = 21.3 years) performed a Navon task, using a global letter made up of local letters of either the same kind (congruent trials) or a different kind (incongruent trials). Findings revealed that active individuals exhibited smaller N2 amplitudes and greater PLVs on incongruent trials that were preceded by incongruent trials compared with those preceded by congruent trials. Such phenomena were not observed for inactive individuals. These results suggest that greater physical activity is associated with larger trial-by-trial adjustments of response conflict, which we attribute to upregulation of top-down cognitive control and reductions in response conflict.

The relation of adiposity to cognitive control and scholastic achievement in preadolescent children

Adiposity may be negatively associated with cognitive function in children. However, the findings remain controversial, in part due to the multifaceted nature of cognition and perhaps the lack of accurate assessment of adiposity. The aim of this study was to clarify the relation of weight status to cognition in preadolescent children using a comprehensive assessment of cognitive control, academic achievement, and measures of adiposity. Preadolescent children between 7 and 9 years (n = 126) completed Go and NoGo tasks, as well as the Wide Range Achievement Test 3rd edition (WRAT3), which measures achievement in reading, spelling, and arithmetic. In addition to BMI, fat mass was measured using dual-energy X-ray absorptiometry (DXA). Data were analyzed with multiple regression analysis, controlling for confounding variables. Analyses revealed that BMI and fat mass measured via DXA were negatively associated with cognitive control, as children with higher BMI and fat mass exhibited poorer performance on the NoGo task requiring extensive amounts of inhibitory control. By contrast, no relation of weight status to performance was observed for the Go task requiring smaller amounts of cognitive control. Higher BMI and fat mass were also associated with lower academic achievement scores assessed on the WRAT3. These data suggest that adiposity is negatively and selectively associated with cognitive control in preadolescent children. Given that cognitive control has been implicated in academic achievement, the present study provides an empirical basis for the negative relationship between adiposity and scholastic performance.

The effects of an afterschool physical activity program on working memory in preadolescent children

The present study examined the effects of a 9-month randomized control physical activity intervention aimed at improving cardiorespiratory fitness on changes in working memory performance in preadolescent children relative to a waitlist control group. Participants performed a modified Sternberg task, which manipulated working memory demands based on encoding set sizes, while task performance and the contingent negative variation (CNV) event-related brain potential were measured. Analyses revealed that the physical activity intervention led to increases in cardiorespiratory fitness and improved Sternberg task performance. Further, the beneficial effects of the physical activity intervention were greater for a task condition requiring greater working memory demands. In addition, the intervention group exhibited larger initial CNV at the frontal electrode site, relative to the waitlist group at post-test; an effect not observed during the pre-test. These results indicate that increases in cardiorespiratory fitness are associated with improvements in the cognitive control of working memory in preadolescent children.

A review of chronic and acute physical activity participation on neuroelectric measures of brain health and cognition during childhood

BACKGROUND

A growing body of research has detailed the beneficial relation of chronic participation in--and acute responses to--physical activity on aspects of cognition that underlie scholastic achievement. Here, we review the relevant neuroelectric findings on this beneficial relation in children, providing support for the influence of physical activity on specific cognitive processes that comprise academic performance.

METHOD

A review of studies examining physical activity and neuroelectric concomitants of cognition during childhood is described. When applicable, research involving adult populations is also described to better inform on this relationship in children.

RESULTS

Collectively, the data support a beneficial relation of chronic and acute participation in physical activity to brain health and cognition. The results suggest more effective allocation of cognitive processes involved in stimulus engagement and action monitoring during tasks requiring variable amounts of cognitive control in children.

CONCLUSION

Physical activity may influence brain health and cognition in children, leading to enhanced scholastic performance and greater overall effective functioning across the lifespan.

The relation of aerobic fitness to neuroelectric indices of cognitive and motor task preparation

The relation of aerobic fitness to task preparation was examined in a sample of young adults separated into higher- and lower-fit groups according to their maximal oxygen consumption. Participants performed a modified Sternberg working memory task under speed and accuracy instructions while measures of task performance and contingent negative variation (CNV) were collected. Analyses revealed no significant fitness differences between groups on task performance measures. However, frontal CNV amplitude was significantly larger for lower-fit participants compared to higher-fit participants during the speed instructions, an effect not found for the accuracy instructions. These results suggest that lower-fit individuals may rely to a greater extent on cognitive control processes to respond under speeded conditions, whereas higher-fit individuals may maintain a more constant level of control irrespective of the task instructions.

General physical activity levels influence positive and negative priming effects in young adults

OBJECTIVE

To investigate the relationship between general physical activity level and the cognitive functions of executive control in young adults using behavioral measures and event-related brain potentials.

METHODS

Forty young adults (mean age=21.1 yrs; 19 females) were differentiated on the basis of their regular physical activity level into two groups: active and sedentary. They performed a spatial priming task consisting of three conditions: control, positive, and negative priming. Spatial priming effects, which are related to executive control and occur automatically, were assessed as indicators of cognitive functioning.

RESULTS

Negative priming effects on reaction time and P3 latency in the active group were larger than in the sedentary group. By contrast, positive priming effects were only observed in the sedentary group.

CONCLUSIONS

The cognitive effects of regular physical activity could be observed using a relatively simple paradigm. The results indicate that regular physical activity has a beneficial effect on the cognitive processes on executive control in young adults.

SIGNIFICANCE

The present study provides additional evidence of the beneficial effects of regular physical activity on cognitive functioning in young adults.

The interactive effect of exercise intensity and task difficulty on human cognitive processing

The interactive effect of exercise intensity and task difficulty on human cognitive processing was investigated using the P3 component of an event-related brain potential (ERP). Exercise intensity was established using Borg's rating of perceived exertion (RPE) scale, and task difficulty was manipulated using a modified flanker task comprised of incongruent and neutral trials. Twelve participants (22 to 30 y) performed the flanker task during a baseline session, and again after light (RPE: 11), moderate (RPE: 13), and hard (RPE: 15) cycling exercise. Results indicated that the P3 amplitude increases across task conditions following light and moderate cycling, but not during hard cycling, relative to baseline, suggesting that P3 amplitude may change in an inverted U fashion by as a result of acute exercise intensity. Additionally, the expected delay in P3 latency for incongruent relative to neutral trials was observed during the baseline condition. However, following acute exercise these task condition differences diminished across exercise intensities. Moreover, reaction times following all exercise conditions were shorter when compared to the baseline condition. These findings suggest that P3 latency is more sensitive to task difficulty manipulated by a flanker task than behavioral measures, and P3 latency during trials requiring greater executive control processes might be more sensitive to the effects of acute exercise than tasks requiring minimal effort.