COGNITIVE REPRESENTATIONS OF FUNCTIONAL INTERACTIONS WITH OBJECTS

Two studies addressed people's knowledge about the movements underlyin g functional interactions with objects, when the interactions were des cribed by simple verbal labels expressing environmental goals. In Expe riment 1, subjects rated each action with respect to six dimensions: w hich portion of the limb moved, distance moved, forcefulness, effector s involved, size of the contact surface, and resemblance to grasp. Rat ings were systematic and fell on two distinct underlying factors relat ed to limb movement and effector (usually the hand) configuration. In Experiment 2, subjects sorted a subset of the actions by similarity of movement. Clustering and multidimensional scaling solutions indicated that the six initial dimensions contributed to similarity judgments, along with additional parameters. The results support the existence of cognitively accessible, but still relatively specific, representation s of functional actions, with potential implications for motor and mem ory performance.