The functional equivalence of imagery and movement.

Abstract

A method of investigating mental imagery is presented which shows that movements and imagery of movements are functionally equivalent. Experiment I uses a short-term-motor-memory linear positioning task in which a novel movement interpolated between initial presentation and recall of a criterion movement length can bias recall. It was predicted that if a similar bias occurred when the interpolated novel movement was imagined rather than performed, then imagery of movements had effects on memory which were functionally similar to producing movements. The results showed that imagery for movements did produce a similar bias. In Experiment II a second order interference task was introduced while instructions to imagine movements were carried out. It was predicted that if imagery for movements were based on the visual/perceptual system then a simultaneous visual inspection task should inhibit imagery. If imagery were based on the motor system though, a simultaneous motor task should prohibit imagery. The results showed that a visual task inhibited imagery. The role of visual imagery in movement control is discussed in terms of spatial representations.