Motor memory – a memory of the future

Motor representations: One or many?

Two issues have been raised. The first concerns whether consciousness is attached to a given type of action. It is argued that purposive actions are represented before being executed and that motor representations can either remain implicit or become explicit according to the task. The second issue concerns whether or not mental imagery of action is independent from action. Recent evidence showing the commonality of neural mechanisms for motor imagery and action, respectively, goes against the idea of independent processes.

Response intention and imagery processes: Locus, interaction, and contribution to motor learning

By way of commentary on Jeannerod (1994), we propose that (1) intention, response imagery, and actual response processes carry equal weight in inferring from one process to another, (2) memory networks control intention, which interacts with imagery-based processing to control response imagery, and (3) response imagery will demonstrate learning effects better when imagery reconstruction and elaboration are emphasized and neutral retention tests are utilized.

Alternative origins of motor images

Jeannerod (1994) advocates studying motor images to understand the representation of action. We identify an unsettled issue that complicates the use of motor images to study the representation of action and present some evidence for a clear absence of equivalence between motor imagery and movement preparation. We then elaborate and emphasize the relevance of the mental practice literature, which was introduced in the first round of commentary. Finally, we suggest two methods that will allow motor imagery theorists to address these points.

In search of nonvisual motor images

Jeannerod's target article and a number of commentators stressed the necessity of distinguishing between motor representation and perceptual images. A patient with a lesion of the central somatosensory pathways allowed us to test for this distinction. The outcome suggests that motor images may not be visual and that the “pragmatic” framework proposed by Jeannerod for vision can apply to other sensory modalities.