The characteristics of arabic orthography slow its processing.

The present study was designed to evaluate whether the complexity of Arabic orthography increases its perceptual load, thus slowing word identification. Adolescent Arabic speakers who mastered Hebrew as a second language completed oral and visual versions of the Trail Making Test (TMT; J. E. Parington & R. G. Lieter, 1949) in both languages. Oral TMT required declaiming consecutive numbers or alternation between numbers and letters. Visual TMT required connecting Arabic or Indian numbers and alternation between letters and numbers. Performance in Hebrew and Arabic oral TMT did not differ. Performance was significantly slower in Arabic visual TMT. These results indicate that Arabic speakers process Arabic orthography (1st language) slower than Hebrew orthography (2nd language) and suggest that this is due to the complexity of Arabic orthography.