Identification and production of graphic symbols by individuals with aphasia: efficacy of a software application

The purpose of the current study was to evaluate the ability of individuals with severe or global aphasia to identify and produce graphic symbols using a software program that turns a microcomputer into an electronic communication device. During the first phase of the treatment program, subjects were trained to identify single symbols and two-symbol combinations from different grammatical categories. The second phase involved training on production of simple subject-verb and subject-verb-object constructions using symbols correctly identified by subjects in the first phase. A single-subject, multiple-baseline design across behaviors replicated across five subjects was used to assess the effects of treatment on symbol identification. Results indicated that all subjects identified noun symbols with a greater degree of accuracy than symbols representing verb referents. Performance on symbol production task varied across subjects. The most frequently observed errors on the symbol production task were omission...