What the visual word recognition skills of prelingually deafened readers tell about their reading comprehension problems

The objective of this study was to clarify the nature and efficiency of the word recognition skills of prelingually deafened Hebrew readers and the way these skills relate to their reading comprehension level. Relevant data were gathered by means of a research paradigm demanding the same/different categorization of phonologically or formationally manipulated word pairs and by a sentence comprehension test (SCT). Participants were prelingually deafened individuals (n=22, mean grade=8.7) who attested to using sign language as their preferred means for communication, and a task-matched hearing control group (n=40, mean grade=8.9). In general, findings suggest that both hearing readers and readers with prelingual deafness rely upon orthographic knowledge rather than upon their primary language for mediating the processing of written words in the working memory (WM). As predicted, in comparison to their hearing counterparts, the reading comprehension of the prelingually deafened participants, as a group, was significantly impaired. Comparative analyses of quantitative and qualitative aspects of the same/different categorizations of word pairs by the participant groups, and the way these correlated with performance on the SCT clearly indicated, however, that this weakness is not rooted in poor word recognition skills but probably reflects a lack of syntactic knowledge crucial for the adequate, post-lexical processing of recognized words. Finally, the findings convincingly show that, despite their profound hearing loss, some individuals who were prelingually deaf acquired rule-based knowledge for the adequate processing of written text.