The relationship between executive functioning ability and communicative success in aphasic adults

The purpose of this study was to test the hypothesis that some aphasic subjects demonstrate a specific impairment in executive function ability, and that this impairment may be related to subjects\u27 use of trained symbols in functional communication situations.^ Fifteen nonfluent aphasic subjects were trained with 20 symbols in three communicative modalities: Communication Board, Gesture, and Verbal. All subjects acquired all symbols in at least one nonverbal modality and maintained at least 80% accuracy in the two nonverbal modalities. Only four of the subjects reached the 80% criteria in the verbal modality. Subjects\u27 use of the symbols was tested during two functional communication tasks: Structured Conversation and Referential Communication. In addition, subjects\u27 executive function ability was examined during performance on four nonverbal problem solving tasks: Porteus Maze, Tower of London, Block Design, and Wisconsin Card Sorting Test. Aphasic subjects\u27 executive function performance was compared to that of neurologically normal controls.^ Results demonstrated that as a group, aphasic subjects spontaneously used approximately 50% of the trained symbols correctly on both communication tasks. Performance significantly increased following a cue. The Verbal modality was used significantly more than Gesture or the Communication Board. Subjects switched modalities only an average of 39% of the time an opportunity was present on the communication tasks. Examination of executive function ability on the nonverbal problem solving tasks demonstrated that aphasic subjects performed significantly worse than normal controls on eight of the ten variables.^ Very few significant correlations were found between executive function performance and both use of trained symbols (5/20) and switching behavior (4/60) on the functional communication tasks. Thus, the relationship between executive function ability and communication remains unclear. However, the manner in which subjects performed on both problem solving and communication tasks was similar. Specifically, performance was characterized by inefficiency, inflexibility, and a need for structure.^ The results of this study are consistent with the theory that the communication deficits observed in aphasic patients result from more than solely impaired linguistic processing. However, further research is necessary to determine the additional processes that contribute to overall communicative behavior.