The present study examined the effect of event segmentation on cognitive control mode use in a sample of older adults (N = 30; Mage = 73, SDage = 4.75) using a modified AX-Continuous Performance Test (AX-CPT). This task included a perceptual event boundary between each cue and its forthcoming probe by means of a spatial shift across the left and right side of the display. Past research showed that young adults' existing proactive control bias could be enhanced in an event segmented AX-CPT relative to their performance on a standard AX-CPT. For older adults who adopt reactive control by default, the event boundary was expected to impede cue-reactivation during probe presentation, and thus further enhance their existing reactive control bias. To examine this, older adults were tested with a standard and an event segmented AX-CPT in two blocks, with error rates revealing a shift toward greater reactive control use in the event segmented relative to the standard AX-CPT. Findings supported our hypothesis that placing a spatial event boundary between each cue and forthcoming probe would further enhance older adults' reactive control bias. This study contributes to the sparse but growing literature on the effects of task-specific manipulations on cognitive control use. The results are discussed in light of the dual mechanisms of control framework and the event horizon model.
Keywords: Cognitive aging; cognitive control; dual mechanisms of control; event horizon model; event segmentation.