Abstract Reading aloud of morphologically complex words has been consistently found to be impaired in acquired dyslexia. This morphological disorder is characterized by the production of larger numbers of errors with complex than with simple words and by the production of so-called morphological errors, i.e. errors that reflect the internal morphological structure of words and are dissociable from purely visual errors. However, most previous research has focused on suffixed words (e.g., payment payment), while much less is known about how prefixed words (e.g., prepay prepay) are affected. In the present study, we report three experiments involving a German speaker with acquired phonological dyslexia. We aimed to provide a characterization of the impairment of prefixed words, as well as to test whether there are systematic differences in how prefixes and suffixes are impaired. Our findings suggest that prefixed words show the same general pattern of morphological impairment previously reported for other types of complex words; however, prefixes tend to be more severely impaired than suffixes. This aligns with accounts proposing that prefixes are acquired and processed less easily than suffixes, and more vulnerable in language loss.
Ciaccio et al. (Tue,) studied this question.