Distinct hippocampal regions make unique contributions to relational memory

Neuroscientific research has shown that the hippocampus is important for binding or linking together the various components of a learning event into an integrated memory. In a prior study, we demonstrated that the anterior hippocampus is involved in memory for the relations among informational elements to a greater extent that it is involved in memory for individual elements (Giovanello et al., 2004. Hippocampus 14:5-8). In the current study, we extend those findings by further specifying the role of anterior hippocampus during relational memory retrieval. Specifically, anterior hippocampal activity was observed during flexible retrieval of learned associations, whereas posterior hippocampal activity was detected during reinstatement of study episodes. These findings suggest a functional dissociation across the long axis of human hippocampus based on the nature of the mnemonic process rather than the stage of memory processing or type of stimulus.