Habitual exercise affects inhibitory processing in young and middle age men and women

Inhibitory processing is an aspect of cognitive control susceptible to cognitive decline due to aging. Engaging in habitual exercise could attenuate these declines in middle age. In the present study, the event-related potential (ERP) activity of 40 middle age adults (21 females) and 42 young adults (24 females) was recorded with electroencephalography (EEG) as participants completed two cognitive tasks that elicit inhibitory processing, one indexing interference control (i.e., the Flanker Task), and the other response inhibition (i.e., the Stop-Signal task). Congruent arrays elicited significantly earlier peaks in P3b activity compared to incongruent arrays in the Flanker task for non-exercisers and young habitual exercisers. For middle age habitual exercisers, this difference was of much smaller magnitude, and non-significant. This finding suggests that the timing of interference control, as indexed by P3b latency, was similar in the congruent and congruent conditions for middle age adults who engaged in regular exercise. On the Stop-Signal task, the P3b activity of habitual exercisers was larger and peaked earlier than that of non-exercisers, indicating that ERP activity signalling response inhibition was enhanced in young and middle age adult regular exercisers. Sex differences were also observed in peak P3b activity on the Flanker task, results which suggest the relationship between regular exercise and interference control differs between men and women. The findings of this study suggest that it is important to consider individual differences, for example sex, when examining the effectiveness of exercise interventions targeting cognitive decline.