Mapping motor representations with positron emission tomography

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.

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

“…Interestingly, the presently observed areas were part of a network showing increased activation in response to rehabilitation using action observation (Ertelt et al, 2007). The absence of more primary sensorimotor activations is in line with early reports (Decety et al, 1994) and may be explained by the chosen task instruction.…”

The Neural-Cognitive Basis of the Jamesian Stream of Thought

“…The fact that these neurons fire both to the appearance and to the performance of the appropriate movement in all these situations indicates that they do more than just control specific muscles: They code a general representation of the movement as a whole. Similar activations of motor areas have been observed in humans using PET during both imagined grasping actions and observations of such actions performed by others (Decety et al, 1994).…”

A Compensatory Mirror Cortical Mechanism for Facial Affect Processing in Schizophrenia

“…There is evidence that imaging a movement is associated with activation of the motor areas that would be normally responsible for generating such movement (Jeannerod and Frak 1999;Schnitzler et al 1997). Resonant or mirroring systems that match execution and observation of an action have been described that may help in the understanding of the behaviors, actions, and intentions of other individuals in society (Gallese et al 1996;Hari et al 1998;Iacoboni et al 1999;Rizzolatti et al 1999;Nishitani and Hari 2000;Rizzolatti and Arbib 1998;Gallese and Goldman 1998;Decety et al 1994). These systems are capable of representing "motor ideas" such as facial movements that convey emotional or intentional states of importance in social communication (Fadiga et al 2000) and thus appear crucial for social functioning and adaptation, deficits of which are well known in schizophrenia.…”

“…Single-unit activity occurring both during behavior observation and action, especially related to hand and mouth gestures, has been recorded from neurons in the premotor cortex of macaque monkeys that supports the operation of those systems, and it has been termed mirror activity (Gallese et al 1996;Rizzolatti et al 1999). Resonant or mirroring systems are believed to have a role in recognizing and interpreting actions or gestures performed by others and their meanings (Gallese et al 1996;Hari et al 1998;Iacoboni et al 1999;Nishitani and Hari 2000;Rizzolatti and Arbib 1998;Gallese and Goldman 1998), as well as in motor rehearsal (Decety et al 1994), imitation (Iacoboni et al 1999;Nishitani and Hari 2000), and learning (Decety et al 1994). Thus, they support social adaptation and functioning.…”