Lateral Somatotopic Organization During Imagined and Prepared Movements

Abstract

Motor imagery is a complex cognitive operation that requires memory retrieval, spatial attention, and possibly computations that are analogs of the physical movements being imagined. Likewise, motor preparation may or may not involve computations that are analogs of actual movements. To test whether motor imagery or motor preparation activate representations that are specific to the body part whose movement is imagined or prepared, participants performed, imagined, and prepared hand movements while undergoing functional MRI scanning. Actual hand movements activated components of the motor system including primary motor and somatosensory cortex, the supplementary motor area, the thalamus, and the cerebellum. All of these areas showed strong lateral organization, such that moving a given hand activated the contralateral cortex and ipsilateral cerebellum most strongly. During motor imagery and motor preparation, activity throughout the motor system was much reduced relative to overt movement. However, significant lateral organization was observed during both motor imagery and motor preparation in primary motor cortex, the supplementary motor area, and the thalamus. These results support the view that the subjective experience of imagined movement is accompanied by computations that are analogs of the physical movement that is imagined. They also suggest that in this regard motor imagery and motor preparation are similar.

Differential Contribution of Bilateral Supplementary Motor Area to the Effective Connectivity Networks Induced by Task Conditions Using Dynamic Causal Modeling

“…Thereby, these two areas have been consistently found to be significantly activated during both motor execution and motor imagery tasks (Gao et al, 2011;Gerardin et al, 2000;Guillot et al, 2008;Hanakawa et al, 2003;Jeannerod, 1994;Michelon et al, 2006;Solodkin et al, 2004;Szameitat et al, 2007). These functional results were largely in agreement with the anatomical findings in monkeys and humans, showing that the SMA was densely and reciprocally connected with the hand area of M1 (Arai et al, 2012;Johansen-Berg et al, 2004;Luppino et al, 1993;Muakkassa and Strick, 1979;Rouiller et al, 1994).…”

Evoking the Imagination as a Strategy of Influence

“…Th e results revealed that the actual hand movements activated components of the motor system, including the primary motor and somatosensory cortex, the supplementary motor area (SMA), the thalamus, and the cerebellum. When participants imagined these movements or prepared to perform them, the primary motor cortex, the SMA, and the thalamus were activated (Michelon, 2005). Similar results have been reported with imagining more complex actions such as running, rowing, or weightlift ing.…”

Neuroimaging Studies of Mental Rotation: A Meta-analysis and Review

“…Regions in the precentral cortex are associated with motor planning and execution, and have been identified with mental rotation since the first neuroimaging studies of mental rotation (Cohen & Bookheimer, 1994). It has been suggested that precentral activity may reflect the use of motor simulation (computations that map to the specifics of joint angles and/or torques; Michelon, Vettel, & Zacks, 2006) to solve mental rotation problems. In other words, participants may simulate moving objects with their hands.…”