| Cardiorespiratory fitness influences on executive control function were assessed for 72 young adults (23 males). Behavioral and neuroelectric indices of action monitoring were obtained while participants completed both a modified flanker task and a modified Sternberg task under task instruction conditions that stressed speed and accuracy. A graded maximal exercise test (GXT) was used to measure cardiorespiratory fitness by assessing maximal oxygen uptake (VO2max). The error-related negativity (ERN), error positivity (Pe), and inhibitory N2 components, as well as behavioral measures of response speed, accuracy, post-error accuracy, and post-error slowing were each regressed on fitness (VO2max percentile) to determine the specific relationships present between indices of action monitoring and cardiorespiratory fitness under the different task instructions. The pattern of findings indicated that higher levels of cardiorespiratory fitness were associated with greater ERN and N2 amplitudes under accuracy instructions in the flanker task. Further, higher levels of fitness were associated with greater modulation of neuroelectric (ERN) and behavioral (post-error accuracy) indices of action monitoring across task instructions in the flanker task. In the Sternberg paradigm, higher fitness was associated with decreased reaction time (RT) for the smallest memory set size under instructions emphasizing speed. Additionally, higher fitness was positively related to improved post-error accuracy under instructions emphasizing accuracy. Finally, during the Sternberg paradigm, higher fitness was associated with greater modulation of post-error accuracy. These findings suggest that higher levels of cardiorespiratory fitness are associated with increased cognitive flexibility, evidenced through greater change in action monitoring as a function of task parameters. Thus, cardiorespiratory fitness may be beneficial to cognitive function by selectively increasing the executive control of attention under task conditions where these processes are more salient. |
