Gesture recognition in aphasia

To study the relationship between verbal and nonverbal behaviour in aphasia, a Gesture Recognition Test (GRT) was given to 111 aphasic patients and to 48 normal controls (NC). Forty-eight aphasics were impaired on the GRT. Global, Wernicke's and Transcortical aphasics performed worse than Broca’s, Conduction and Anomic aphasics, whose scores did not differ from those of NC. Although a moderate to strong correlation was found between GRT and auditory comprehension performances, type of aphasia had an effect on gesture recognition that was independent of the severity of auditory comprehension impairment. This may reflect the major role played by posterior left-hemispheric areas in the identification of gestures. GRT impairment was associated with reading defects only in patients with central alexia. A strong correlation was found with constructional apraxia, suggesting that these two nonverbal tasks share common neural mechanisms. The weak association between gesture recognition impairment and ideomotor apraxia supports an independence between “receptive” and “expressive” aspects of gestural communication.