RESPONSE PREPARATION BEGINS BEFORE MENTAL ROTATION IS FINISHED - EVIDENCE FROM EVENT-RELATED BRAIN POTENTIALS

Behavioral data (response time (RT) and accuracy) and psychophysiologi cal data (event-related brain potentials or ERPs, and lateralized read iness potential or LRP) were studied in an experiment in which rotated alphanumeric characters were presented normally or mirror-reversed. I n half of the trials, character classification (letter versus digit) d etermined whether or not the response was to be executed (go versus no go) and parity determined the responding hand. In the other half, clas sification determined the responding hand and parity determined go ver sus nogo. LRP data indicated that response preparation occurred before mental rotation was finished. These data contradict strictly sequenti al discrete models of information processing and suggest continuous fl ow of information. (C) 1998 Elsevier Science B.V. All rights reserved.