Time-dependent Transformation of Episodic Memories

Although there has been over a century of research on memory and consolidation, there remains no consensus with respect to the nature of episodic memories over time. This study tests two prominent theories (Standard Consolidation Theory and Trace Transformation Hypothesis), which make opposing predictions as to the quality of remote episodic memory, by investigating memories for film clips. Using true/false questions to test recall immediately, 3 days, and 7 days after encoding, these experiments demonstrate that details (both perceptual and story-line details) are lost, while the gist of memories is maintained over time. These data also suggest that gist and detail may be maintained independently in the brain. These results broaden our understanding of recent and remote memory, and provide support for the transformation view of consolidation. In the future, the transfer of this paradigm to neuroimaging will allow us to investigate the neural basis of episodic memory over time.MAS