Hierarchical relational binding in the medial temporal lobe: the strong get stronger.

Controversy exists over the functional role of the medial temporal lobe (MTL) in episodic memory. Some have suggested that the hippocampus plays a unique and qualitatively different role than other MTL regions, whereas others suggest that the entire MTL has one functional role, which is to support the consolidation of declarative memories. Hierarchical relational binding theory (hRBT) purports that the functional role of the entire MTL is the binding of features associated with an episodic experience. As the hippocampus sits at the top of this hierarchy, binding at this level is particularly efficient in reinstating event features at the time of retrieval. Thus, this theory offers a unified account of MTL that yields outcomes similar to theories that suggest a special role of the hippocampus. In this way, hRBT captures features of both single- and dual-process models of MTL and reconciles controversies about the nature of episodic recollection.