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Abstract: Extensive research indicates that, in right-handed individuals, words and faces are processed by two distinct neural systems: one in the left hemisphere (LH) for words, and the other in the right hemisphere (RH) for faces. Emerging evidence suggests, however, that hemispheric selectivity for words and for faces may not be independent of each other. In fact, one recent account suggests that words become lateralized to the LH in order to be in close proximity to language regions, and subsequently, as a result of competition with words for representational space, faces become lateralized to the RH. On this account, left-handed individuals, whose cortical organization is more variable with respect to hemispheric language dominance, would also be expected to show more variability in their degree of RH lateralization of faces. The current study uses event related potential (ERPs) to compare the hemispheric specialization for both words and faces in right- and left-handed adult individuals. While both right- and left-handed groups demonstrated a LH over RH superiority for words, only the right-handed group demonstrated a RH over LH advantage for faces. Consistently, there was not a statistically significant relationship between handedness and the degree of hemispheric superiority for word processing, but increased right-handedness was related to an increase in RH superiority for face processing, as measured by the strength of the N170 ERP component. Interestingly, the degree of RH superiority for face processing could be predicted by the magnitude of the N170 ERP response to words in the LH. These results are discussed in terms of a theoretical account in which the typical RH face lateralization fails to emerge in left-handers because of a lack of competition from the LH representation of words.

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