Imagery of voluntary movement of fingers, toes, and tongue activates corresponding body-part-specific motor representations

Abstract

voluntary movement of fingers, toes, and tongue activates correspond-ing body-part–specific motor representations. J Neurophysiol 90: 3304–3316, 2003; 10.1152/jn.01113.2002. We investigate whether imagery of voluntary movements of different body parts activates somatotopical sections of the human motor cortices. We used func-tional magnetic resonance imaging to detect the cortical activity when 7 healthy subjects imagine performing repetitive (0.5-Hz) flexion/ extension movements of the right fingers or right toes, or horizontal movements of the tongue. We also collected functional images when the subjects actually executed these movements and used these data to define somatotopical representations in the motor areas. In this study, we relate the functional activation maps to cytoarchitectural popula-tion maps of areas 4a, 4p, and 6 in the same standard anatomical space. The important novel findings are 1) that imagery of hand movements specifically activates the hand sections of the contralatera