Visual similarity effects in the identification of Arabic letters: evidence with masked priming

Research using masked priming and parafoveal preview techniques has shown that visual letter similarity has an impact on word processing during the initial stages in Latin-derived scripts. However, these effects appear to be absent in Arabic. One reason for this discrepancy could be attributed to the distinctive features of the Arabic script, which includes numerous letters sharing a basic form while varying in the location or number of diacritics. To shed light on this issue, the present study employed Arabic letters rather than words in two masked priming experiments: an alphabetic decision task and a letter-matching task. Both experiments showed that visually similar letters were more effective as primes than visually dissimilar letters. These findings suggest that the processes of letter identification in Arabic and Latin scripts may be roughly alike, implying that differences in visual letter similarity across scripts may arise at later stages of processing.