HEMISPHERIC-DIFFERENCES IN IMAGE GENERATION AND USE IN THE HAPTIC MODALITY

Forty adults and 40 children, all right-handed, were presented with ei ther of two series of six nonsense shapes to palpate: Those who were d ivided into sections by grid lines and thus provided categorical infor mation or those who provided a whole shape and coordinate information that could be processed globally. Subjects were given an Input conditi on where they formed a mental representation of the shape while palpat ing the unseen tactual stimulus with either hand, followed by an Evalu ation condition in which they attempted to solve the task by generatin g and using the previously stored image. Evaluation response times sho wed that the left hemisphere was significantly faster at generating im ages from categorically stored information. Neither hemisphere had an advantage when generating an image from globally stored information. ( C) 1994 Academic Press, Inc.