Functional anatomy of storage, recall, and recognition of a visual pattern in man

With the purpose of mapping the anatomical structures participating in memory of visual patterns, we measured regional cerebral blood flow (rCBF) as an indicator of synaptic metabolism in eleven volunteers during four conditions: rest, visual learning of colored geometrical patterns, recall with the eyes closed, and recognition of the patterns. Learning changed rCBF in the primary visual cortex, visual association areas, temporal pole, anterior hippocampus, dorsal thalamus, caudate nucleus, putamen, and the anterior cingulate cortex. Recall and recognition changed rCBF in other limbic, thalamic, and striatal sectors. Only the highest order parieto-occipital visual areas were activated during recall. These areas were assumed to be the storage sites. It was inferred that the limbic and striatal circuits participating in learning were replaced by other limbic and thalamic circuits to recall and recognize the learned patterns.