Neural binding mechanisms in learning and memory

Binding mechanisms are considered as basic cognitive operations, performing different functions in learning and memory. This review will cover two of these binding mechanisms: relational binding of information about stimuli and actions with their spatio-temporal context into a circumscribed cognitive event and representational binding of feature representations common to a number of such events, thereby integrating these representations with existing knowledge and, thus, leading to decontextualized knowledge about the world. I will survey evidence from recent neuropsychological, electrophysiological and neuroimaging studies, including my own work, demonstrating that relational binding operations are performed within the hippocampal system, whereas representational binding is subserved by the surrounding medial-temporal lobe cortex and prefrontal brain areas. I then present examples of conditions that differentially implement both binding mechanisms. Lastly, summarizing the extant literature on binding mechanisms I speculate on whether these binding mechanism operate in a similar way across different cognitive domains or whether they are domain-specific. (C) 2009 Elsevier Ltd. All rights reserved.