Training to perform certain movements, even blindfolded, affects our subsequent ability to perceive those same movements when performed by others. That’s according to Antonino Casile and Martin Giese at the University Clinic Tubingen, who say their finding reinforces the notion of an intimate link between how we control our own body and how we perceive the movements of others.
Casile and Giese tested participants’ ability to match images made up of lights that had the appearance of a person walking with one of three different rhythms. Imagine a person walking in the pitch-black darkness with a little light on each of their joints and you have an idea of what these images look like (see here).Participants were shown pairs of these ‘point-light’ images, and had to say in each case whether the two images showed the same walking rhythm or not.
Blindfolded to prevent any visual stimulation, the participants were then taught to walk with one of these awkward, unnatural rhythms. Crucially, when they were subsequently tested on the visual matching again, the participants showed a significant improvement, but only when matching two point-light displays that moved with the same walking rhythm they’d just been trained on. Moreover, motion-capture technology was used to determine how well the participants had learned the walking rhythm, and this showed that the better the participants learned to perform the rhythm, the greater their subsequent improvement in matching the associated point-light displays.
The researchers said “Our study shows, for the first time, a direct and highly selective influence of novel acquired motor programmes on visual action recognition that is independent of visual learning”.
But how does learning a movement affect our perception of that movement? The researchers explained the effect: “…might be mediated by the visual imagination of motor patterns during the motor training”. “Indeed”, they said, “experimental evidence suggests that motor imagination, action perception, and motor production might share common neuronal substrates”.
Casile, A. & Giese, M.A. (2006). Nonvisual motor training influences biological motion perception. Current Biology, 16, 69-74.