Selective attention to prior knowledge modulates default network activity in support of cognitive control

Poster Session A - Saturday, April 13, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Veronica Diveica¹ (veronica.diveica@mcgill.ca), Roni Setton², Gary Turner³, Nathan Spreng¹; ¹Montreal Neurological Institute, ²Harvard University, ³York University

The default network (DN) has traditionally been considered a task-negative large-scale functional network that decreases its activity during cognitively demanding tasks, such as those requiring working memory. Recent research, however, found increased DN activation when successful cognitive control benefited from access to long-term memory. Here, we investigated whether selective attention to prior knowledge modulates DN’s contribution to cognitive control. In an fMRI study, 31 healthy young adults engaged in an N-back task involving working memory for famous (linked to prior knowledge), and anonymous, faces/places. Participants were instructed to focus exclusively on famous stimuli in certain task blocks and on anonymous stimuli in others. Consequently, famous stimuli were task-relevant in the former blocks and task-irrelevant in the latter. At the whole-brain level, multivariate partial least squares analyses revealed greater activation of DN and control regions in response to task-relevant (compared to task-irrelevant) stimuli, regardless of stimulus fame. However, multivoxel pattern analyses showed that local DN activation patterns distinguished between both task-relevant and irrelevant stimuli, and between famous and anonymous stimuli. Cross-decoding analyses showed that the activity patterns distinguishing the fame of task-relevant stimuli differed from those distinguishing the fame of task-irrelevant stimuli, suggesting inter-dependence between representations of fame and task goal information within DN regions. These results demonstrate that DN activity is shaped by the interplay between prior knowledge and top-down attentional constraints. They support DN’s active involvement in orchestrating both long-term memory access and task goal representation, challenging its traditional task-negative characterization and endorsing its pivotal contribution to executive control.

Topic Area: EXECUTIVE PROCESSES: Goal maintenance & switching