Task-driven intra- and interarea communications in primate cerebral cortex

TL;DR

This study quantifies directional neural correlations across cortical areas during a cognitive task, revealing task-dependent communication pathways and the disappearance of correlations when sensory comparison is no longer needed.

Contribution

It introduces a nonparametric Bayesian method to analyze directional neural correlations in multiple cortical areas during different task stages.

Findings

Neural correlations involve feedforward and feedback paths during decision making.

Correlations significantly delay across cortical areas during certain task intervals.

Majority of correlations vanish when sensory comparison is not required.

Abstract

Neural correlations during a cognitive task are central to study brain information processing and computation. However, they have been poorly analyzed due to the difficulty of recording simultaneous single neurons during task performance. In the present work, we quantified neural directional correlations using spike trains that were simultaneously recorded in sensory, premotor, and motor cortical areas of two monkeys during a somatosensory discrimination task. Upon modeling spike trains as binary time series, we used a nonparametric Bayesian method to estimate pairwise directional correlations between many pairs of neurons throughout different stages of the task, namely, perception, working memory, decision making, and motor report. We find that solving the task involves feedforward and feedback correlation paths linking sensory and motor areas during certain task intervals. Specifically, information is communicated by task-driven neural correlations that are significantly delayed across secondary somatosensory cortex, premotor, and motor areas when decision making takes place. Crucially, when sensory comparison is no longer requested for task performance, a major proportion of directional correlations consistently vanish across all cortical areas.