MEMORY DYSFUNCTION IN MILD APHASICS

The effect of mild aphasia (n = 9), as a result of subarachnoid haemor rhage (SAH), was evaluated against one matched (sex, age, and educatio n) control group suffering from SAH of unknown origin without aphasia, and against one matched healthy control group. According to aphasia t esting (Reinvang & Engvik, 1980), criteria for a classical diagnosis w ere not met. Therefore, the patients were characterized as mild aphasi cs: They generally displayed intact audo-verbal comprehension and repe tition abilities, and they demonstrated a fluent, spontaneous speech. However, they showed phonemic and semantic paraphasias, with self-corr ections; a few patients displayed alexia and agraphia. Memory performa nce of these three groups was evaluated by a neuropsychological test b attery, designed to tap various components of verbal memory function. From the results it was concluded that: (a) Short-term memory is impai red, as regards the phonological loop and the central executive in wor king memory, whereas maintenance rehearsal is unaffected, given that t he demands on phonological coding is minimized, (b) long-term memory i s also generally impaired, whereas long-term learning and forgetting b y means of subject-performed tasks proceeds within a normal range. Imp airments were hypothesized to reflect less efficient central executive functions of working memory, involving generation of less appropriate semantic codes and phonological representations, (c) mildy aphasic pa tients are not subjectively aware of their own memory deficits, and (d ) aphasia classification by means of standard procedures do not suffic iently characterize the nature of a mildy aphasic patient's memory pro blems.