The Function of Oscillations in the Hippocampal Formation 12 Colin Lever, Raphael Kaplan, and Neil Burgess Abstract Some of the strongest experimental and computational links between oscillations and cognition concern the oscillations in the hippocampal formation supporting spatial and mnemonic processing. We review experimental and theoretical work concerning well-established hippocampal oscillations such as theta, gamma, and high-frequency ripples and how they relate to spatial, mnemonic, and anxiety- related representation and behaviour. We specifically consider the following computational roles for oscillations: organising processing into discrete chunks, as seen in encoding versus retrieval scheduling; ordinal and metric coding by oscillatory phase; temporal integration by oscillatory phase; and interregional communication. The literature on oscillations has typically been concerned with changes in band-specific power. Here, focusing on the theta oscillation, we summarise how key variables are linked not only to power but also to frequency and to coherence. We conclude that the hippocampal formation provides an invaluable model system for understanding the functional roles of neuronal oscillations and the interaction between oscillations. C. Lever ( *) Department of Psychology, University of Durham, Durham DH1 3LE, UK e-mail:
[email protected] R. Kaplan Laboratory of Brain and Cognition, National Institute of Mental Health, Bethseda, MD, USA UCL Institute of Cognitive Neuroscience, London WC1N 3AR, UK N. Burgess ( *) UCL Institute of Cognitive Neuroscience, London WC1N 3AR, UK UCL Institute of Neurology, London WC1N 3BG, UK e-mail:
[email protected] D. Derdikman and J.J. Knierim (eds.), Space, Time and Memory in the 303 Hippocampal Formation, DOI 10.1007/978-3-7091-1292-2_12, # Springer-Verlag Wien 2014 304 C.