Poster B20, Thursday, August 16, 3:05 – 4:50 pm, Room 2000AB

Encoding of abstract letter identity in deaf readers: the role of lexical feedback

Eva Gutierrez-Sigut1,2, Marta Vergara-Martínez1, Manuel Perea1,3;1University of Valencia, 2University College London, 3Basque Center on Cognition, Brain, and Language

Most deaf people find reading very difficult. Here we analyzed whether this was partly due to weaker lexical feedback during orthographic encoding. In an ERP masked identity priming experiment with hearing readers, Vergara-Martínez et al.’s (2015) behavioral data showed no advantage for matched-case over the mismatched-case (RTs: HOUSE-HOUSE = house-HOUSE) for words, whereas there was an advantage for nonwords (RTs: SOUTA-SOUTA < souta-SOUTA). Furthermore, the ERPs showed a matched-case effect in the N/P150 component that dissipated for words (but not for nonwords) in the N250 and N400 components. Vergara et al. (2015) argued that the absence of case effects in words (but not in nonwords) was due to top-down lexical modulation. Critically, in a behavioral masked priming experiment with deaf readers, Perea et al. (2016) found an advantage of the matched-case over the mismatched-case condition for both words and nonwords, and argued that this was due to a weaker lexical feedback in deaf than in hearing readers. In the present experiment, we use a more sensitive measure, ERPs, to investigate the time course of abstract letter identity encoding with the matching-case priming manipulation in a group of 20 congenitally deaf readers. Participants made lexical decisions to five-letter Spanish word and nonword targets. The target stimuli were presented in uppercase and preceded by: a) a matched-case identity prime (ALTAR-ALTAR); b) a mismatched-case identity prime (altar-ALTAR); or c) an unrelated prime. Behavioral results replicated the pattern reported by Perea et al. (2016) with deaf readers: we found an advantage for matched-case over the mismatched-case condition for both word and nonword targets. Interestingly, the ERP results showed a similar pattern to that of Vergara-Martínez et al. (2015) with hearing individuals. Specifically, we found a main effect of case N/P150, which dissipated for words (but not for nonwords) in later time windows (N250 and N400). In addition, the analysis of the relationship between this effect and several reading comprehension and phonological processing measures showed that: i) there were no significant correlations between the size of the ERP effects of case and reading/phonological processing measures; ii) the effect of case in response times for words (but not for nonwords) was positively correlated with reading ability and phonological skills, as well as with word knowledge. Taken together, these findings favor the view that processing of orthographic features during word processing may follow a different pattern in deaf readers than in hearing readers.

Topic Area: Perception: Orthographic and Other Visual Processes