Hemisphere memory of concrete and abstract information determined with the intracarotid Sodium Amytal test.

An extended version of the bilateral intracarotid Sodium Amytal test was administered pre-operatively to 13 patients with intractable complex partial epileptic seizures, to determine cerebral hemisphere speech and memory. There were 6 patients with left temporal lobe lesions and 7 patients with right temporal lobe lesions. Amobarbital (175 mg, 10%), injected on 2 occasions, determined the left hemisphere to be speech dominant in all cases. Memory assessed with recall, cued recall, and recognition of concrete/abstract words and pictures, was studied on 3 occasions: in a baseline test considered to indicate the degree of patient cooperation and the bilateral hemisphere memory; in a right hemisphere Amytal test; and in a left hemisphere Amytal test. The specific data pattern obtained, that abstract pictorial information is most efficiently processed by an intact right hemisphere and that verbal information is processed best by an intact left hemisphere, demonstrates the reliability of the approach taken here to present abstract and concrete to be remembered information.