Pantomime comprehension and ideomotor apraxia.

In a prior study it was shown that apraxic patients with posterior infarctions that included the parietal lobe could not discriminate between gestures. In this study these observations were replicated using a nonverbal paradigm in which the subjects did not have to discriminate between gestures, but instead had to comprehend their meaning. Pantomimed acts on videotape were shown to six apraxic-aphasic patients, seven nonapraxic-aphasic patients, and six normal subjects. Four drawings were also shown, one of which matched the pantomime (for example, if the pantomime was of hammering, one drawing was of a nail and three were foils). Subjects responded by pushing a button corresponding to the desired picture. The apraxics made more errors than the aphasics or controls.