“Non-Necessary Neural Activity in the Primate Cortex”, Sébastien Tremblay, Camille Testard, Jeanne Inchauspé, Michael Petrides2022-09-13 (neuroscience)⁠:

When neurophysiologists record neural activity from the brain, they often conclude that neural tuning to task variables indicates a functional role of the brain area studied in task performance. However, it remains unknown how reliably such correlations indicate a functional role.

To answer this question, we chronically recorded neural activity in the prefrontal cortex of monkeys during the performance of 4 cognitive tasks. Previous studies had demonstrated that only one of those tasks causally depends on the recorded area; the other 3 tasks are not impaired by lesions of this area.

We found that the prevalence and strength of single neuron and ensemble tuning were equivalently high across all 4 tasks.

This suggests that non-necessary cognitive signals are prevalent in the cerebral cortex of primates during task performance, challenging one of the fundamental assumptions of cognitive neurophysiology.