Relations among neural activities recorded in premotor and motor cortex of trained monkeys during visually guided hand and arm movement tasks

Earlier we have found synchronized oscillations in motor cortical areas of awake behaving monkeys (Sanes and Donoghue, Proc. Natl. Acad. Sci. USA 90 (1993) 4470-4474 and Donoghue et al., J. Neurophysiol. 79 (1998) 159-173). In the reaching task, local held potentials (LFPs) were not directionally tuned, while neuronal responses were clearly modulated with the direction of arm movement. We are now screening the data with 7.5 s records each, using power spectra, coherence, phase and cross-correlation functions in sliding windows and averaged for 20 trials aligned for target, go cue or movement onset. Our findings indicate that unique neural activity patterns characterize different time segments of a sensorimotor task which is also reflected in LFP recordings. (C) 1999 Published by Elsevier Science B.V. All rights reserved.