Directional tuning and reference frames revealed by noninvasive EEG in humans: a computational MoBI study

Abstract

Movement directional tuning is a hallmark that characterizes the response properties of neurons in the motor-related areas found in single-unit recording studies of monkeys. This study attempted to estimate the width of directional tuning from scalp EEG signals in humans by combining of Mobile Brain/Body Imaging (MoBI) and computational modeling. First, a computational model of population of spiking neurons suggests that the width of directional tuning may be estimated from temporal correlations of simulated EEG signals, provided that responses of model neurons are temporally heterogeneous. Then, neural activities and body movements were monitored with high-density EEG and motion capture while subjects made center-out reaching movements toward one of eight targets separated by 45 degrees. As predicted by computational modeling, EEG source dipoles exhibited directional tuning with various tuning widths. MoBI combined with computational modeling provides a noninvasive alternative for understanding neural mechanisms that have hitherto required invasive recordings in animals.