PT  - JOURNAL ARTICLE
AU  - Christoph T. Weidemann
AU  - Michael J. Kahana
TI  - Neural measures of subsequent memory reflect endogenous variability in cognitive function
AID  - 10.1101/576173
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 576173
4099  - http://biorxiv.org/content/early/2020/08/13/576173.short
4100  - http://biorxiv.org/content/early/2020/08/13/576173.full
AB  - Human cognition exhibits a striking degree of variability: Sometimes we rapidly forge new associations whereas at other times new information simply does not stick. Correlations between neural activity during encoding and subsequent retrieval performance have implicated such “subsequent memory effects” (SMEs) as important for understanding the neural basis of memory formation. Uncontrolled variability in external factors that also predict memory performance, however, confounds the interpretation of these effects. By controlling for a comprehensive set of external variables, we investigated the extent to which neural correlates of successful memory encoding reflect variability in endogenous brain states. We show that external variables that reliably predict memory performance have relatively small effects on electroencephalographic (EEG) correlates of successful memory encoding. Instead, the brain activity that is diagnostic of successful encoding primarily reflects fluctuations in endogenous neural activity. These findings link neural activity during learning to endogenous states that drive variability in human cognition.Competing Interest StatementThe authors have declared no competing interest.