When learning hurts control: inducing cross-task-covariance causes multitasking costs

Abstract

Performing two tasks concurrently typically leads to performance costs. Historically, multitasking costs have been assumed to reflect fundamental constraints of cognitive architectures. A new perspective proposes that multitasking costs reflect information sharing between constituent tasks; shared information gains representational efficiency, at the expense of multitasking capability. We test this theory by determining whether increasing cross-task information harms multitasking. 48 participants performed multitasks where they mapped keypresses to four shapes. In a subsequent statistical learning task, these shapes then formed pairs that were predictive or non-predictive of an upcoming target judgement. When participants again responded to these shapes in the multitasking context, performance was poorer when the shape pair had been predictive of target outcomes in the learning phase, relative to non-predictive. Thus, associating common information to shape pairings transferred to negatively impact multitasking performance, providing the first causal evidence for the shared representational account of multitasking performance.

Individual differences fill the uncharted intersections between cognitive structure, flexibility, and plasticity in multitasking.

“…With a focus on multitasking, variance in structure creates the basis for different manifestations of multitasking performance and related costs. In that respect, dual-task costs can be considered as resulting from insufficient attentional resources and/or the (in)ability to inhibit interfering tasks or stimuli acting together with basic processes prone to interference from other tasks (Garner et al, 2021).…”