Phase Dynamics as Bridge between Thought and Behavior

Ongoing thoughts play a critical role in modulating cognitive performance, with phenomena such as mind wandering consistently associated with decreased task accuracy and prolonged RTs. However, the neural mechanisms underlying the influence of thought dimensions on cognition and behavior remain unclear. To elucidate this, we used EEG to investigate how two key thought dimensions-deliberate control (deliberate vs. spontaneous thoughts) and task relatedness (on-task vs. off-task thoughts)-modulate RT during a simple RT task. Behavioral results showed that both on-task and more deliberate thoughts were associated with shorter RTs compared to off-task and more spontaneous thoughts. Neurodynamic analyses revealed that on-task and deliberate thoughts were characterized by prestimulus increases in both frequency sliding, reflecting faster phase-based neural speed, and sample entropy, reflecting higher neural uncertainty/flexibility. Both prestimulus frequency sliding and sample entropy were significantly related to the degree of poststimulus intertrial phase coherence, which, in turn, correlated with RT. This sequential relationship suggests that phase-based neural dynamics play a crucial role in mediating the relationship of thought with task-related behavior. Together, these findings suggest that phase-based neural dynamics could play a key modulatory role across the divide of prestimulus and poststimulus activity in shaping the influence of ongoing thoughts (deliberate control and task relatedness) on task execution and its related behavior (RT).