Cortico-subcortical dynamics in primate working memory

Working memory is essential for cognition, facilitating the temporary maintenance and manipulation of information to produce goal-directed behavior. While both cortical and subcortical structures are involved, their precise roles and interactions are not fully understood. To investigate this, we simultaneously recorded neural activity from the frontal and parietal cortex, higher-order thalamic nuclei, and core basal ganglia structures during color and spatial working memory tasks in non-human primates. We found widespread yet differential encoding of color and spatial information, marked by area-specific temporal dynamics and modulation according to task demands. Both cortical and subcortical information increased towards working memory-dependent actions, suggesting a task-specific reloading of information. Directed interactions between cortical and subcortical regions were extensive and reciprocal, with dominant directions of information flow, especially from frontoparietal areas. These interactions were dynamically modulated and partially task specific. Our findings provide comprehensive insights into the large-scale circuit dynamics underlying primate working memory and suggest that flexible goal-directed behavior relies on the selective processing of task-relevant memory information within information-specific cortico-subcortical networks.