The influence of neural signal on neural variability during hand reaching movement: A simulation model

Neural response as a random process is noisy. The neural response to sensory stimulus is completely equivalent to a list of the spike times in the spike train. Decrease of neuronal response variability revealed in various area of cortex during motor preparatory in reaching task. The reasons of reduction in neural variability (NV) is unknown whether It could be influenced by increasing of firing rate or a result of intrinsic characteristic of cells during reaction time (RT). For this purpose, we simulated a neural response function with an underlying deterministic instantaneous firing rate signal and a random poisson process spike generator. We compared our simulated results with measured neural variability in different level of activity on our alert monkeys during motor intention on three area of brain in direct reach task. The simulation result was agreed with the experimental results a sharp reduction of NV during motor intention or execution.