Visual Arabic Word Recognition during Subliminal and Supraliminal Presentations: A Lexical Decision Study in Normal and Disabled Readers

This study aimed at assessing visual word recognition in normal skilled (NRs) and disabled adult Arabic readers (DRs) using masked subliminal and supraliminal word presentations in a lexical decision task (LDT). The main assumption of this investigation was that, as a consequence of their reading disability, DRs would exhibit slower reaction times (RTs) and lower performance than NR in the supraliminal condition. By contrast, since words identified subliminally are thought to occur thanks to advanced orthographic (not phonological skills), it was assumed that this presentation mode would diminish the differences between DRs and NRs. RTs and d’ detection measures were analyzed in 59 NRs and 21 DRs who had to decide whether visually presented letter strings corresponded to real Arabic words or to pseudowords. The statistical analyses conducted on RTs and d’ showed that, although both groups showed a lexicality effect (faster RTs for words than for pseudowords), the DRs compared to NRs showed longer RTs and lower detection measures in the supraliminal mode. Importantly, in the subliminal mode, no group effect was found in terms of RTs and the size of the difference between groups in terms of detection decreased. Also, in this latter presentation condition, we observed that the lexicality effect was significant in the DRs but not in the NRs. These findings are discussed in relation to other studies indicating that DRs might have benefited from good orthographic skills, on which they rely to compensate for their phonological deficits.