The effect of the internal orthographic connectivity of written Arabic words on the process of the visual recognition: A comparison between skilled and dyslexic readers

Previous research has suggested that reading Arabic is more challenging than reading Hebrew or English, even among native Arabic readers due to the visual complexity of the Arabic orthography. In particular, the fact that most of the Arabic letters connect to each other and change their basic form according to their place in the written word (beginning, middle or end) has been hypothesised to constitute a visual load affecting reading efficiency. Here, we tested this visual complexity hypothesis by manipulating word-internal orthographic connectivity during visual word recognition. Fifty-eight adult skilled readers and 20 disabled readers of Arabic performed a lexical-decision task using words (and nonwords) whose letters were naturally fully connected (Cw), partially connected (PCw) and nonconnected (NCw). Behavioural measures for words as a function of word connectivity (and word frequency) were analysed using repeated measures analysis of variance. The results revealed that within both groups of readers, higher accuracy rates were measured for the Cw rather than for the NCw, with PCw falling in between. The analysis of the individual standard deviations of the response times within each word condition revealed that Cw yielded a response variance lower than NCw, again with PCw in between. These results indicate that Cw tend to be processed more efficiently and accurately than NCw, in both reader groups. The results presented here extend recent findings in normal readers and indicate that word connectivity does not negatively impact word recognition processes among adults. The psycholinguistic and neurolinguistic implications of these findings are discussed.