Abstract:
Brain activity was mapped in normal subjects during passive
observation of the movements of an 'alien' hand and while imagining
grasping objects with their own hand. None of the tasks required actual
movement. Shifting from one mental task to the other greatly changed the
pattern of brain activation. During observation of hand movements,
activation was mainly found in visual cortical areas, but also in
subcortical areas involved in motor behaviour, such as the basal ganglia
and the cerebellum. During motor imagery, cortical and subcortical areas
related to motor preparation and programming were strongly activated.
These data support the notion that motor learning during observation of
movements and mental practice involves rehearsal of neural pathways
related to cognitive stages of motor control