Interhemispheric relations and the functions of the minor hemisphere

Luria AR , Simernitskaya EG. Neuropsychologia 1977; 15: 175-178.

The authors propose a novel theory of brain reorganization wherein active, intentional memorization is governed by the dominant hemisphere, and involuntary or incidental memory depends upon the nondominant hemisphere. They introduce their relucatance to divide the hemispheres into verbal and nonverbal realm, but to further parse. He quotes Goldstein (1948) regarding the dedifferentiation of figure and background, and Bernstein NA (M0scow, 1948 in Russian) for the disorganization of movement.

The subjects were given lists of 10 unrelated 2 and 3 syllable words and asked to memorize them. The percentage retrieved was an indication of voluntary memory. In the second experiment subjects were asked to count the number of words with the letter K or thenumber of letters in the series. Then, retrieval was assessed as a measure of passive memory. The subjects were fifteen patients with left hemisphere lesions, fifteen with right hemisphere lesions, and fifteen normal controls (college students). The results showed that left hemisphere lesions were particularly impaired on active memorizing, whereas the right hemisphere patients were severely impaired on passive memorization. The right hemisphere lesion group showed catastrophic results on passive memorization. The authors speculate the findings indicated the concentration of attention on the conscious non memory task blocked the retrieval of background traces.

Caplan B (Hemispheric dominance for intentional and automatic processes: a test of the Luria and Simernitskaya hypotheses Neuropsychologia 22:247 1984) proposes the results were more consistent with material specific deficits following unilateral lesions.