Awake Sharp-Wave Ripple Replay Of Mental Experiences Critical For Learning

Jadhav SP, Kemere C, German PW, Frank LM (2012), “Awake hippocampal sharp-wave ripples support spatial memory”, Science, 336(6087): 1454-1458.
  The hippocampus is essential for storing and retrieving daily memories, and the neurophysiological basis of memory is a key question. A major focus in the field has been the activity of place cells and its role in spatial navigation, but how this relates to episodic memory is a matter of debate. Although SWRs that occur during sleep after behavior were thought to support memory consolidation, critically, neither place cell activity nor SWRs that occur in the awake state had been linked causally to memory. We hypothesized that awake replay events during SWRs could underlie memory formation and retrieval (Review in Nature Neuroscience, 2011). We addressed this important question by developing innovative techniques to detect specific hippocampal activity patterns in real-time and to eliminate them during behavior, and demonstrated that hippocampal replay during awake SWRs is required for learning and spatial memory.

Featured in a NIH news article:
“Awake mental replay of past experiences critical for learning”.