Single and multi-finger movements are correlated in neuronal population activities as well as in natural behaviors

Behaviorally multi-finger movements can be treated as a direct combination of individual finger motions. Although physical interactions among multi-fingers are easy to identify, corresponding simultaneous activation or correlation of M1 neurons is not readily evident. By exploiting neuronal correlation between single and multi-finger movements, this paper presented an answer on whether neurons encode multi-finger movements independently or as a certain neuronal network of single finger movements. Data were recorded from 115 task-related neurons in the M1 hand representation of a male rhesus monkey (Macaca mulatta) performing 18 different types of single and multi-finger movement. We observed very clear neuronal correlation during finger movements, especially, for the high responding neuron group. Also, the results in the paper may trigger an application for controlling dexterous prosthetic hand.