Poster E125, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
Repetition enhancement for partially repeated words in left occipitotemporal cortex
Zhiheng Zhou1, Carol Whitney2, Lars Strother1; 1Department of Psychology, University of Nevada, Reno, 2Independent Researcher
A “visual word form area” (VWFA) in left occipitotemporal cortex is often implicated in the neural representation of whole words. We used a rapid event-related fMRI to investigate the effects of partial word repetition on neural responses in the VWFA. Specifically, we presented observers with three- and four-letter word pairs. During each word-pair event, the words changed either in part or in full such that three-letter words (e.g. POT) were followed by words containing the same letters (e.g. SPOT or POTS) or by a word that shared no letters. Words were presented to either the right (RVF) or to the left (LVF) of fixation, or a combination of locations within a word-pair event. Results from a previous fMRI study (Strother et al., 2016) that employed partial word changes led us to expect repetition suppression in the VWFA and more posterior regions in the left hemisphere. Surprisingly, we instead observed “repetition enhancement” for word pairs with partially repeated letters (POT-SPOT), even when successive locations of paired words differed within an event. We did not, however, observe enhancement for word pairs limited to the LVF. We propose that the observed repetition enhancement in the VWFA reflects reactivation of letters shared between two words, which requires that at least one of the words in a pair projects contralaterally to the VWFA.
Topic Area: PERCEPTION & ACTION: Vision