Aphasic and amnesic patients' verbal vs. nonverbal retentive abilities

Four different groups of patients (aphasics, alcoholic Korsakoffs, chronic alcoholics, and control patients) were asked to detect either repeated words presented orally, repeated words presented visually, repeated pictures or repeated shapes, during the presentation of a list of similarly constructed stimuli. It was discovered that on the verbal tasks, the number of words intervening between repetitions had more effect on the aphasics than on the other groups of patients. However, for the nonverbal picture repetition and shape repetition tasks, the aphasics' performance was normal, while the alcoholic Korsakoff patients were most affected by the number of intervening items. It was concluded that the aphasics' memory deficit demonstrated by the use of this paradigm was specific to the presentation of verbal material.