Frontal effective connectivity increases with task demands and time on task: a Dynamic Causal Model of electrocorticogram in macaque monkeys

TL;DR

This study uses Dynamic Causal Models to analyze electrocorticogram data from macaque monkeys, revealing that frontal effective connectivity increases with task difficulty and over time, reflecting heightened attentional effort.

Contribution

It provides a computational model linking task demands and time-on-task effects to changes in frontal effective connectivity in macaques.

Findings

Forward connectivity between fronto-parietal regions increases with task difficulty.

Effective connectivity strengthens as the session progresses.

Changes in connectivity relate to increased attentional effort.

Abstract

We apply Dynamic Causal Models to electrocorticogram recordings from two macaque monkeys performing a problem-solving task that engages working memory, and induces time-on-task effects. We thus provide a computational account of changes in effective connectivity within two regions of the fronto-parietal network, the dorsolateral prefrontal cortex and the pre-supplementary motor area. We find that forward connections between the two regions increased in strength when task demands increased, and as the experimental session progressed. Similarities in the effects of task demands and time on task allow us to interpret changes in frontal connectivity in terms of increased attentional effort allocation that compensates cognitive fatigue.