Theta and high-frequency activity mark spontaneous recall of episodic memories.
Publication/Presentation Date
8-20-2014
Abstract
Humans possess the remarkable ability to search their memory, allowing specific past episodes to be re-experienced spontaneously. Here, we administered a free recall test to 114 neurosurgical patients and used intracranial theta and high-frequency activity (HFA) to identify the spatiotemporal pattern of neural activity underlying spontaneous episodic retrieval. We found that retrieval evolved in three electrophysiological stages composed of: (1) early theta oscillations in the right temporal cortex, (2) increased HFA in the left hemisphere including the medial temporal lobe (MTL), left inferior frontal gyrus, as well as the ventrolateral temporal cortex, and (3) motor/language activation during vocalization of the retrieved item. Of these responses, increased HFA in the left MTL predicted recall performance. These results suggest that spontaneous recall of verbal episodic memories involves a spatiotemporal pattern of spectral changes across the brain; however, high-frequency activity in the left MTL represents a final common pathway of episodic retrieval.
Volume
34
Issue
34
First Page
11355
Last Page
11365
ISSN
1529-2401
Published In/Presented At
Burke, J. F., Sharan, A. D., Sperling, M. R., Ramayya, A. G., Evans, J. J., Healey, M. K., Beck, E. N., Davis, K. A., Lucas, T. H., 2nd, & Kahana, M. J. (2014). Theta and high-frequency activity mark spontaneous recall of episodic memories. The Journal of neuroscience : the official journal of the Society for Neuroscience, 34(34), 11355–11365. https://doi.org/10.1523/JNEUROSCI.2654-13.2014
Disciplines
Medicine and Health Sciences
PubMedID
25143616
Department(s)
Department of Medicine
Document Type
Article