Reading in deaf individuals: ERP studies at the word and sentence level

Carreiras, M. . 1, 2, 3 , Dias, P. 1 , Fariña, N. 1 & Costello, B. . 1

2 Ikerbasque, Basque Foundation for Science

Despite the difficulties associated with learning to read in the absence of audition, some deaf readers achieve proficient reading skills. We conducted a series of behavioural and EEG studies on 20 deaf proficient readers of Spanish (a language with a transparent orthography and rich inflectional morphology) to discover what processing mechanisms underlie skilled reading in deaf individuals compared to hearing controls.
At the word level, we examined the relative roles of phonological and orthographic encoding by manipulating pseudohomophone and transposed letter effects. The results reveal that skilled deaf readers can achieve lexical access without phonological encoding, contradicting previous claims that phonology is an essential step when reading a transparent language like Spanish
At the sentence level, the mechanisms underlying morphosyntactic processing were probed using grammatical violation paradigm on the features of number, transparent gender and opaque gender. The results show that deaf skilled readers handle morphsyntactic relations such as number and gender agreement similarly to hearing controls. Group differences in conditions in which relations involve explicit form patterns (e.g. transparent gender) suggest that deaf readers make greater use of any orthographic consistencies while also processing abstract features (i.e. transparent gender) without difficulty.