DYNAMICS OF NEURONAL INTERACTIONS IN MONKEY CORTEX IN RELATION TO BEHAVIORAL EVENTS

IT is possible that brain cortical function is mediated by dynamic mod ulation of coherent firing in groups of neurons. Indeed, a correlation of firing between cortical neurons, seen following sensory stimuli or during motor behaviour, has been described(1-5). However, the time co urse of modifications of correlation in relation to behaviour was not evaluated systematically. Here we show that correlated firing between single neurons, recorded simultaneously in the frontal cortex of monke ys performing a behavioural task, evolves within a fraction of a secon d, and in systematic relation to behavioural events. Moreover, the dyn amic patterns of correlation depend on the distance between neurons, a nd can emerge even without modulation of the firing rates. These findi ngs support the notion that neurons can associate rapidly into a funct ional group in order to perform a computational task, at the same time becoming dissociated from concurrently activated competing groups. Th us, they call for a revision of prevailing models of neural coding tha t rely solely on single neuron firing rates(6-8).