Abstract
Words and faces have vastly different visual properties but increasing evidence suggests that word and face processing involve 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 object types in the left and right hemispheres, respectively. Furthermore, individuals with prosopagnosia and dyslexia exhibit deficits in both face and word perception. To investigate whether overlapping neural mechanisms of face and word processing can manifest in perceptual interference in healthy individuals, we presented images using rapid serial visual presentations at 10Hz. In three experiments, participants (N = 42, 20, 20) discriminated two face, word and glasses targets (T1 and T2) embedded in the image stream. As expected, second target discrimination was impaired when it followed the first target by 200-300ms relative to longer inter-target intervals, the so-called "attentional blink". Interestingly, T2 identification was much lower at short inter-target intervals when a face target was followed by a word compared with glasses-word and word-word combinations, indicating that face processing interfered with word perception. Faces did not cause a larger "blink" for the other stimulus types. The opposite effect was not observed; that is, a word T1 did not impair face T2 discrimination more than the other object types. The same pattern of results was observed for different target identification tasks and relative image sizes. EEG results indicated face T1 processing impaired word T2 processing at the N170 component. Taken together, the results suggest face processing specifically interferes with word processing, providing evidence for overlapping neural mechanisms of these two object types. Furthermore, asymmetrical face-word interference points to a difference in the temporal aspects of face and word processing such that faces processing interferes with word perception but not vice versa.
Meeting abstract presented at VSS 2016