Effects of hippocampal brain damage on auditory and visual recent memory: comparison with marijuana-intoxicated subjects.

A battery of tests clinically employed for the estimation of auditory and visual recent memory dysfunction was administered to eight subjects having circumscribed damage to the temporal lobe. It was hypothesized that the performance of subjects with temporal lobe lesions would qualitatively resemble that of subjects intoxicated with marijuana. Where comparisons could be made, the performance of these "temporal lobe" patients paralleled the performance of subjects acutely intoxicated with known doses of delta 9-THC. Results are discussed in terms of cannabinoid actions on hippocampal functioning and, in general, support the hypothesis that the action of marijuana in the brain may focus in the hippocampal region and produce behavioral changes similar to that resulting from traumatic injury or removal of the region.