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bioRxiv · 10.1101/2021.04.30.442192

EEG biomarkers of free recall

Kahana, M. J.·Katerman, B. S.·Keane, C.·Li, Y.·Pazdera, J. K.
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Abstract

Brain activity in the moments leading up to spontaneous verbal recall provide a window into the cognitive processes underlying memory retrieval. But these same recordings also subsume neural signals unrelated to mnemonic retrieval, such as response-related motor activity. Here we examined spectral EEG biomarkers of memory retrieval under an extreme manipulation of mnemonic demands: subjects either recalled items after a few seconds or after several days. This manipulation helped to isolate EEG components specifically related to long-term memory retrieval. In the moments immediately preceding recall we observed increased theta (4-8 Hz) power (+T), decreased alpha (8-20 Hz) power (-A), and increased gamma (40-128 Hz) power (+G), with this spectral pattern (+T-A+G) distinguishing the long-delay and immediate recall conditions. As subjects vocalized the same set of studied words in both conditions, we interpret the spectral +T-A+G as a biomarker of episodic memory retrieval.

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Kahana, M. J., Katerman, B. S., Keane, C., Li, Y., Pazdera, J. K.. 2021-05-01. EEG biomarkers of free recall. https://doi.org/10.1101/2021.04.30.442192

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