Word and Face Processing Engage Overlapping Distributed Networks: Evidence From RSVP and EEG Investigations
Words and faces have vastly different visual properties, but increasing evidence suggests that word and face processing engage overlapping distributed networks. For instance, fMRI studies have shown overlapping activity for face and word processing in the fusiform gyrus despite well-characterized lateralization of these objects to the left and right hemispheres, respectively. To investigate whether face and word perception influences perception of the other stimulus class and elucidate the mechanisms underlying such interactions, we presented images using rapid serial visual presentations. Across 3 experiments, participants discriminated 2 face, word, and glasses targets (T1 and T2) embedded in a stream of images. As expected, T2 discrimination was impaired when it followed T1 by 200 to 300 ms relative to longer intertarget lags, the so-called attentional blink. Interestingly, T2 discrimination accuracy was significantly reduced at short intertarget lags when a face was followed by a word (face–word) compared with glasses–word and word–word combinations, indicating that face processing interfered with word perception. The reverse effect was not observed; that is, word–face performance was no different than the other object combinations. EEG results indicated the left N170 to T1 was correlated with the word decrement for face–word trials, but not for other object combinations. Taken together, the results suggest face processing interferes with word processing, providing evidence for overlapping neural mechanisms of these 2 object types. Furthermore, asymmetrical face–word interference points to greater overlap of face and word representations in the left than the right hemisphere.