Perceptual Learning of Tooling Affordances of a Jointed Object via Dynamic Touch

We investigated whether perceptual learning via dynamic touch can facilitate the discovery of tooling affordances. Twelve blindfolded participants manipulated two structurally identical aluminum objects consisting of a blade and a shaft; one object was seven and a half times heavier than and twice as large as the other object. Flexions/extensions at two joints in the shaft changed the configuration and functionality of each object. A rigid shaft (one of four possible configurations) rendered each object a functional hoe. The number of changes in the configuration produced prior to determining that the grasped object had been rendered a functional hoe greatly exceeded the number of possible configurations and declined with experience, whereas the rate of change in configuration increased with experience. Inertial properties specifically support perception via dynamic touch and explained the observed differences in actions with the two objects. These findings demonstrate that perceptual learning via dynamic touch can facilitate the discovery of tooling affordances.