Avoiding sedentary behaviors requires more cortical resources than avoiding physical activity: An EEG study

Why do individuals fail to exercise regularly despite knowledge of the risks associated with physical inactivity? Automatic processes regulating exercise behaviors may partly explain this paradox. Yet, these processes have only been investigated with behavioral paradigms based on reaction times. Here, using electroencephalography, we investigated the cortical activity underlying automatic approach and avoidance tendencies toward stimuli depicting physical activity and sedentary behaviors in 29 young adults who were physically active (n=14) or physically inactive but with the intention of becoming physically active (n=15). Behavioral results showed faster reactions when approaching physical activity compared to sedentary behaviors and when avoiding sedentary behaviors compared to physical activity. These faster reactions were more pronounced in physically active individuals and were associated with changes during sensory integration (earlier onset latency and larger positive deflection of the stimulus-locked lateralized readiness potentials) but not during motor preparation (no effect on the response-locked lateralized readiness potentials). Faster reactions when avoiding sedentary behaviors compared to physical activity were also associated with higher conflict monitoring (larger early and late N1 event-related potentials) and higher inhibition (larger N2 event-related potentials), irrespective of the usual level of physical activity. These results suggest that additional cortical resources were required to counteract an attraction to sedentary behaviors. Data and Materials [https://doi.org/10.5281/zenodo.1169140].

Evidence of Change of Intention in Picking Situations

Intending to perform an action and then immediately executing it is a mundane process. The cognitive and neural mechanisms involved in this process of “proximal” intention formation and execution, in the face of multiple options to choose from, are not clear, however. Especially, it is not clear how intentions are formed when the choice makes no difference. Here we used behavioral and electrophysiological measures to investigate the temporal dynamics of proximal intention formation and “change of intention” in a free picking scenario, in which the alternatives are on a par for the participant. Participants pressed a right or left button following either an instructive visible arrow cue or a visible neutral “free-choice” cue, both preceded by a masked arrow prime. The goal of the prime was to induce a bias toward pressing the left or right button. Presumably, when the choice is arbitrary, such bias should determine the decision. EEG lateralized readiness potentials and EMG measurements revealed that the prime indeed induced an intention to move in one direction. However, we discovered a signature of “change of intention” in both the Instructed and Free-choice decisions. These results suggest that, even in arbitrary choices, biases present in the neural system for choosing one or another option may be overruled and point to a curious “picking deliberation” phenomenon. We discuss a possible neural scenario that could explain this phenomenon.