The ideation of movement is supported by fronto-temporal cortical regions involved in the retrieval of semantic knowledge

Abstract

Background and aim of the work: The neurofunctional correlates of movement ideation, which should be distinguished from motor imagery, have not been fully investigated. This functional Magnetic Resonance Imaging (fMRI) experiment revealed the brain activation patterns associated with different motor processes, including ideation. Methods: Fifteen healthy participants underwent fMRI and performed three tasks using the right index finger: 1. execution of a simple prespecified movement; 2. execution of a simple voluntary movement; 3. ideation of a simple voluntary movement without execution. A number of t-test comparisons across conditions were carried out. Results: The execution of a simple prespecified finger movement activated the right inferior parietal cortex and substantia nigra, the left middle frontal gyrus ,and thalamus, and bilaterally the post-central gyri, the superior parietal lobule and the cerebellum. Execution of a simple voluntary movement activated the left anterior cingulate cortex. The ideation of a voluntary simple movement activated the left inferior, middle and superior temporal gyri and the inferior frontal gyri bilaterally. Conclusions: The execution of a prespecified action involves structures within the somatosensory cortex, such as the post-central gyrus. The execution of a voluntary action is achieved with the support of the anterior cingulate cortex, a structure active when resolution of conflict is required. The ideation of a voluntary action requires the contribution of associative areas of the left frontal and temporal lobes, which support the retrieval of semantic knowledge necessary in the planning of a voluntary act.