Increased interhemispheric functional connectivity during non-dominant hand movement in right-handed subjects

Abstract

Hand preference is one of the behavioral expressions of lateralization in the brain. Previous fMRI studies, using conventional task-based functional MRI (fMRI), investigated the lateralization of brain function, and several regions including the motor cortex, putamen, thalamus, and cerebellum were activated during the single-hand movement. However, lateralization of functional connectivity related to hand preference has not been investigated. Here, we used the generalized psychophysiological interaction (gPPI) approach to investigate the alteration of functional connectivity during single-hand movement from the resting state in right-hand subjects. The functional connectivity in interhemispheric motor-related regions including the supplementary motor area, putamen, precentral gyrus, and cerebellum was significantly increased during non-dominant hand movement, while functional connectivity was not increased during dominant hand movement. The general linear model (GLM) showed activation in the left supplementary motor area, left precentral gyrus, and right cerebellum during right hand movement and activation in the right supplementary motor area, right precentral gyrus, and left cerebellum during left hand movement. These results indicate that a combination of GLM and gPPI analysis can detect the lateralization of hand preference more clearly in right-handed subjects.