Speed of face recognition in humans: an event-related potentials study

EVENT-related potentials (ERPs) were measured while subjects passively look ed at a line drawing of a normal face or a line drawing in which parts of t he face were scattered so as not to be recognized as a face (scattered face ) in order to estimate the speed of face recognition in humans. Because the spatial frequencies of these two types of line drawings were very similar, one could minimize the potentials due to the structure coding stage of the face processing. In addition, passive viewing of these stimuli eliminates the contribution of other processing such as discrimination or memory retri eval. Comparing these two conditions, statistically significant positive po tentials were observed in frontal areas from 135 ms after stimulus onset fo r the normal face. These early positive differences mere probably due to th e face processing per se in human visual recognition. Although statisticall y significant differences were observed in frontal areas, these are probabl y related to fusiform or inferior temporal area activation that is often re ported using neuro-imaging technologies such as PET or fMRI. (C) 1999 Lippi ncott Williams & Wilkins.