When accomplishing goal-directed behavior in naturalistic settings our globalphysiological state can vary dramatically, oscillating between periods of wakefulness,
emotional stress, and physical activity. Fluctuations in global state, in turn, induce a cascade
of neuromodulatory changes that affect how the brain processes sensory information from the
external environment. Despite the inextricable link between global state and brain function,
goal-directed behavior has predominantly been studied when the body is stationary and at
rest. Thus, it is unclear as to whether perturbations in global state modulate cognitive
processes dependent on this sensory information, such as working memory (WM). The
current body of work aims to determine how changes in global state induced by an acute bout
of aerobic exercise modulate WM and its underlying neural correlates. Study 1 investigated
the relationship between acute exercise and cognition, which revealed that aerobic exercise
induces a small enhancement in general task-performance. Moderator analyses indicated that
time-dependent measures of cognition were especially improved by exercise-induced
perturbations in global state. Importantly, executive functions, such as inhibitory control and
WM, were influenced by engaging in physical activity. Building on these meta-analytic
results, Study 2 investigated whether the fidelity of spatial WM representations is impacted during an instance of aerobic exercise. Participants completed a delayed change detection
task both at rest and during a bout of low-intensity cycling while neural activity was
concurrently recorded using electroencephalography (EEG). An inverted encoding modeling
technique was employed to estimate location-selective channel response functions from
topographical patterns of alpha-band (8-12 Hz) activity. Importantly, robust spatially
selective responses were reconstructed both at rest and during exercise throughout the
stimulus encoding and retention period, demonstrating for the first time that the fidelity of
spatial WM representations could be tracked in a physiologically active state. The selectivity
of these responses was degraded during exercise relative to rest, suggesting that the fidelity
of location representations may be diminished. Study 3 further investigated the impact of
exercise on WM encoding and maintenance abilities. Participants completed a delayed
change detection task that consisted of varying set sizes. Importantly, on some of the trials
participants were required to encode target stimuli while simultaneously ignoring distractors,
thus enabling the evaluation of WM filtering efficiency. Analyses of an event-related
potential known as contralateral delay activity (CDA), which tracks the number of items
stored in WM, indicated that there was no difference in WM load between rest and exercise
conditions. Decoding analyses revealed that patterns of voltage potentials across the scalp
tracked WM load both at rest and during exercise. These results suggest that WM filtering
efficiency and the number of items that can be actively stored are robust to perturbations in
global state caused by light intensity exercise. Together, this collection of studies illuminates
the selective impact of exercise on WM processes, and highlights the importance of
considering global state when developing theoretical frameworks of cognition.