Dynamics of neuronal interactions: Relation to behavior, firing rates, and distance between neurons

This report describes exploration of the hypothesis that cortical function is mediated by dynamic modulation of coherent firing in groups of neurons. We recorded neuronal activity in the frontal cortex of behaving monkeys and found that correlation between neurons changed frequently within a fraction of a second and in relation to behavior. Those modulations can happen without modulation of firing rates. When firing rates are modulated, the modulation of correlation is not related to it in a simple way. Moreover, the dynamic patterns of correlation depend on the distance between neurons. These findings support the notion that, in order to perform a computational task, neurons can associate rapidly into a functional group, while dissociating from concurrently activated competing groups.