Temporal information and trait impulsivity guide prefrontal preparatory activity
Jacqueline R. Janowich1, James F. Cavanagh1; 1University of New Mexico
Cognitive control helps guide behavior by instantiating rules. It is well-known how rule instantiation is elicited from predictable temporal demands, but it remains unknown if rules are encoded and maintained differently when temporal demands vary dynamically. To assess how control mechanisms vary by temporal delay, we recorded EEG while healthy young adult participants (n=38) performed a Dot Pattern Expectancy (DPX) task with cues indicating the upcoming rule and the length of the upcoming delay (short, long, or unknown). Trait impulsivity was measured to gauge how mechanisms for temporally-guided rule instantiation may vary by individual differences in impulsiveness/planning. Rule type and delay information significantly modulated prefrontal response to cues. Temporal Principal Component Analysis (PCA) revealed that a high degree of variance was explained by prefrontal midline (AFz) activity late in the cue-probe delay interval (750-1000 ms post-cue). The slope of anticipatory ERP activity in this window showed a significant delay x rule interaction, with rare rules of known short duration eliciting the steepest slopes, and common rules preceding a known (short/long) delay triggering the flattest slopes. Trait impulsivity scores predicted significant variance in these patterns, with more impulsive participants showing larger slopes for rare rules. These findings describe a novel mechanism by which rule timing information may instantiate divergent anticipation processes guiding behavior, and highlight how this processing is modulated by individual differences in impulsivity.
Topic Area: EXECUTIVE PROCESSES: Goal maintenance & switching