@article{9b5a2773cf6049ffa854208aa28cf149,
title = "Neural fatigue influences memory encoding in the human hippocampus",
abstract = "Here we examine the variability underlying successful memory encoding. Successful encoding of successive study items may fatigue encoding resources, thus decreasing the ability to encode subsequent items (Tulving and Rosenbaum, 2006); alternatively, successful encoding may be persistent, leading to more successful encoding (Kahana, Aggarwal, and Phan, 2018). Analyzing intracranial electroencephalographic activity while subjects studied lists of words for subsequent free recall, we examined high-frequency activity (HFA) in hippocampus and dorsolateral prefrontal cortex (DLPFC), as HFA was greater for subsequently recalled than non-recalled items in these regions. We compared non-recalled items with good encoding history (i.e. one of the two preceding items was recalled) with non-recalled items with poor encoding history (i.e. neither prior item was recalled). In the hippocampus, good encoding history led to reduced HFA, whereas in the DLPFC, good encoding history led to enhanced HFA. Hippocampal findings appear consistent with the neural fatigue hypothesis, whereas the DLPFC results appear consistent with persistent encoding states.",
keywords = "Encoding, Episodic memory, Memory, Temporal lobe, iEEG",
author = "Lohnas, {Lynn J.} and Lila Davachi and Kahana, {Michael J.}",
note = "Funding Information: We would like to especially thank Marijke Beulen, Joshua Jacobs and Mijail Serruya who carried out important preliminary analyses that informed our work. We also owe a special debt of gratitude to Endel Tulving, who suggested that we pursue this question and provided valuable discussion related to this work. We thank Blackrock Microsystems for providing neural recording and stimulation equipment. This work was supported by the DARPA Restoring Active Memory (RAM) program [Cooperative Agreement N66001-14-2-4032]; and National Institutes of Health [grant numbers MH106266, MH55687]. The views, opinions, and/or findings contained in this material are those of the authors and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government. Funding Information: We would like to especially thank Marijke Beulen, Joshua Jacobs and Mijail Serruya who carried out important preliminary analyses that informed our work. We also owe a special debt of gratitude to Endel Tulving, who suggested that we pursue this question and provided valuable discussion related to this work. We thank Blackrock Microsystems for providing neural recording and stimulation equipment. This work was supported by the DARPA Restoring Active Memory (RAM) program [Cooperative Agreement N66001-14-2-4032 ]; and National Institutes of Health [grant numbers MH106266 , MH55687 ]. The views, opinions, and/or findings contained in this material are those of the authors and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government. Publisher Copyright: {\textcopyright} 2020 Elsevier Ltd",
year = "2020",
month = jun,
doi = "10.1016/j.neuropsychologia.2020.107471",
language = "English (US)",
volume = "143",
journal = "Neuropsychologia",
issn = "0028-3932",
publisher = "Elsevier",
}