What does neuroimaging tell us about the role of prefrontal cortex in memory retrieval?

The past five years have seen an outpouring of neuroimaging studies of memory - using both positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). These studies have convincingly demonstrated that neuroimaging can be used to study the functional anatomy of normal human memory and that neuroimaging can precisely localize memory related brain activations within small areas of cortex. To illustrate the application of neuroimaging in the study of memory, this review shows how several laboratories have produced data that converge on the notion that specific areas in the prefrontal cortex are active during long-term memory retrieval. Moreover, the data further suggest that distinct prefrontal brain areas might make differential contributions to different kinds of long-term memory retrieval.