Visual hand primes and manipulable objects

In three experiments we assessed whether priming a handshape activated motor information. Primes consisted ofphotographs of hands displaying one of three postures(precision, power, open hand). Targets consisted ofphotographs (Experiment 1 and 3) or words (Experiment 2) ofobjects, artifacts and natural kinds, manipulable with aprecision (pencil) or with a power grip (bottle). Participantshad to categorize objects into artifacts or natural kinds bypressing a different key. They had to respond to target-objectsonly when the targets followed the precision and the powerprimes, while they didn't have to respond when the targetsfollowed the open hand (catch-trial). In Experiments 1 and 2,artifacts were processed slower than natural kinds, and naturalkinds graspable with a power grip were processed faster thanthose graspable with a precision grip. These results confirmthat visual primes activate general motor information onobjects. However, only in Experiment 3, in which a motortraining phase lead participants to associate a specific visualprime with a motor action, we found an interaction betweenKind of Prime (precision, power) and Kind of Grip (precision,power grip). Results suggest that vision and motorinformation are strictly interwoven and support theoriesaccording to which object concepts are grounded insensorimotor experience.