8. Pre-stimulus interhemispheric coupling of brain rhythms predicts cognitive-motor performance in healthy humans

Abstract

Human actions are characterized by time-varying engagement of functional distributed networks within the brain. We investigated whether specific pre-stimulus interhemispheric connectivity, as a measure of synchronized network between the two brain hemispheres, could lead to a better performance (as revealed by reaction-time) in a simple visuomotor task. Eighteen healthy adults underwent electroencephalographic recording during a visual go/no-go task. In the go/no go task, were presented random visual stimulus (50% green or red). Subjects had to press the mouse button after the green stimuli. Interhemispheric coupling was evaluated by the spectral coherence among all the electrodes covering one hemisphere and matched with those on the other. The task-related results showed that interhemispheric connectivity decreased in delta and increased in alpha band. Furthermore, were observed positive delta and negative alpha correlations with the reaction time. The best performance is anticipated by the better functional coupling of cortical circuits involved during the processing of the sensorimotor information, occurring between the two hemispheres pending cognitive go/no-go task. The present study provides direct confirmation for a stochastic linking of cortical areas, as revealed by oscillatory synchronization of the two hemispheres in selected EEG rhythms, in determining behaviour performance in a cognitive-motor task.