Behavioral performance modulates spike field coherence in monkey prefrontal cortex.

To investigate neuronal processing during short-term memory, we analyzed behavior-related modulations of coupling between signals on two spatial scales: first, very local multiunit activity and second, local field potentials. Coupling was assessed by spike field coherence using a new approach to overcome limitations in cases of low firing rates. We demonstrate the reliability of our approach with simulated data. Application to recordings in prefrontal cortex of two monkeys revealed that locking of spikes was differentially modulated with two different frequency bands depending on behavioral performance.