Partially Overlapping Neural Networks for Real and Imagined Hand Movements

Abstract

Neuroimagery findings have shown similar cerebral networks associated with imagination and execution of a movement. On the other hand, neuropsychological studies of parietal-lesioned patients suggest that these networks may be at least partly distinct. In the present study, normal subjects were asked to either imagine or execute auditory-cued hand movements. Compared with rest, imagination and execution showed overlapping networks, including bilateral premotor and parietal areas, basal ganglia and cerebellum. However, direct comparison between the two experimental conditions showed that specific cortico-subcortical areas were more engaged in mental simulation, including bilateral premotor, prefrontal, supplementary motor and left posterior parietal areas, and the caudate nuclei. These results suggest that a specific neuronal substrate is involved in the processing of hand motor representations.

Cortical activation during executed, imagined, observed, and passive wrist movements in healthy volunteers and stroke patients

“…A reason for this may be that motor imagery is more difficult for patients so that additional neural resources are recruited for task performance. However, most previous studies in healthy subjects showed that neither movement complexity (as an operationalization for movement difficulty and task demands) nor motor imagery proficiency affect the neuroanatomical correlates of MI (Boecker et al, 2002;Gerardin et al, 2000;Guillot et al, 2008;Lehericy et al, 2004) (but see Kuhtz-Buschbeck et al, 2003). Thus, an alternative explanation would be that the extended activations in patients as compared to HVs mimic the pattern observed for overt attempted execution.…”

“…These areas are involved in motor control in general (Gerardin et al, 2000;Roland, 1984;Stephan et al, 1995) and in posture control of the wrist in particular (Suminski et al, 2007). In patients, the attempt to overtly move the left (paretic) wrist recruited the same areas plus a number of additional regions.…”

Shared electrophysiology mechanisms of body ownership and motor imagery

“…These regions have been involved in a number of studies in motor imagery (see reviews from Grèzes and Decety, 2001;Munzert et al, 2009). Several studies using neuroimaging (Kosslyn et al, 2001), transcranial magnetic stimulation (Ganis et al, 2000), or clinical investigations (Sirigu et al, 1996) showed that motor imagery shares neural mechanisms with movement planning (Decety et al, 1989) and movement execution (Gerardin et al, 2000;Parsons et al, 1995), in particular in premotor cortex (e.g. Ionta et al, 2010) and parietal cortex (e.g.…”

The mechanism of self-recognition in humans

“…These studies show the existence of a cortical and subcortical network activated during both motor imagery and action observation. This network involves structures directly concerned with motor execution, such as motor cortex, dorsal and ventral premotor cortex, lateral cerebellum, basal ganglia; it also involves areas concerned with action planning, such as dorsolateral prefrontal cortex and posterior parietal cortex (see [49]). Concerning primary motor cortex itself, fMRI studies unambiguously demonstrate that pixels activated during contraction of a muscle are also activated during imagery of a movement involving the same muscle [50].…”