Scott Small, MD is using a new functional magnetic resonance imaging (fMRI) analysis to identify which sub-regions of the hippocampus correlate with memory decline. His technique measures subtle changes in oxyhemoglobin levels, allowing him to see smaller structures in the brain. He has also used fMRI to examine multiple sites across the long axis of the hippocampal formation while subjects performed different phases of an associative memory task, learning to associate faces with names. The analysis revealed hippocampal circuit mechanisms that underlie memory encoding and retrieval.