Neural correlates of diacritics in Arabic: An fMRI study

Though diacritics are a central feature of Arabic reading, their cognitive and neural effects remain less well understood. The present study used functional magnetic resonance imaging (fMRI) to investigate differences between brain activation patterns associated with real words with versus without diacritics in adult Arabic readers using a lexical decision task. We found no significant difference in accuracy between real words with and without diacritics. However, real words with no diacritics yielded shorter response times and stronger activation in the hippocampus and middle temporal gyrus, possibly reflecting a search among multiple lexical entries that may be associated with these words. In contrast, real words with diacritics yielded longer response times and activated the insula and inferior frontal areas, suggesting an engagement of phonological and semantic processes in recognizing words with diacritics. Taken together, the results support a linguistic role for diacritics in isolated word recognition even in experienced Arabic readers.

► We show, for the first time, the neural correlates of word recognition in Arabic.
► Neural evidence of diacritic processing in isolated word recognition in Arabic.
► Even in experienced Arabic readers, diacritics play a linguistic role.