Defects of immediate memory related to the cerebral blood flow distribution

Different forms of memory defects were studied in 16 patients with organic dementia. The test performance was related to the regional cerebral blood flow (rCBF) in the left (dominant) hemisphere. Verbal memory (Paired Associates) correlated to the blood flow in temporal and parietal regions. Spatial recognition (Memory for Objects, Memory for Geometrical Design) correlated to the temporal and lower frontal regions. One spatial memory test (Visual Retention test) correlated to the temporal region only. Another spatial memory test (Memory for Design) did not show correlations to any regions of the dominant hemisphere. Finally it was found that the hemisphere mean flow values did not correlate to performance. This emphasizes the main finding—the regional correlations. It is concluded that memory performance involves various extratemporal regions depending upon the specific quality of the memory task to be performed.