Understanding Sleep and Dreams

While human cognition during the waking state is of obvious interest, it is equally fascinating what happens while we are asleep. Despite an enormous literature on this topic remarkable little is known about the fundamental mechanisms of sleep activity in the human brain or the purpose of those activities. Our current research is focused on understanding how some of the characteristic rhythms and elements of sleep arise in the human cortex. We are also examining the role of sleep during memory formation and consolidation and how we might be able to use neuromodulatory techniques to impact this function of sleep.


Dickey CW, Sargsyan A, Madsen JR, Eskandar EN, Cash SS, Halgren E. Travelling spindles create necessary conditions for spike-timing-dependent plasticity in humans. Nat Commun. 2021 Feb 15;12(1):1027. DOI: 10.1038/s41467-021-21298-x.

Krempp C, Paulk AC, Truccolo W, Cash SS, Zelmann R. Effect of Closed-Loop Direct Electrical Stimulation during Sleep Spindles in Humans. Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:3586-3589. DOI: 10.1109/EMBC44109.2020.9175404.

Abou Jaoude M, Sun H, Pellerin KR, Pavlova M, Sarkis RA, Cash SS, Westover MB, Lam AD. Expert-level automated sleep staging of long-term scalp electroencephalography recordings using deep learning. Sleep. 2020 Nov 12;43(11):zsaa112. doi: 10.1093/sleep/zsaa112.

Eichenlaub JB, Biswal S, Peled N, Rivilis N, Golby AJ, Lee JW, Westover MB, Halgren E, Cash SS. Reactivation of Motor-Related Gamma Activity in Human NREM Sleep. Front Neurosci. 2020 May 12;14:449. doi: 10.3389/fnins.2020.00449.

Eichenlaub JB, Jarosiewicz B, Saab J, Franco B, Kelemen J, Halgren E, Hochberg LR, Cash SS. Replay of Learned Neural Firing Sequences during Rest in Human Motor Cortex. Cell Rep. 2020 May 5;31(5):107581. doi:10.1016/j.celrep.2020.107581.

Jiang X, Gonzalez-Martinez J, Cash SS, Chauvel P, Gale J, Halgren E. “Improved identification and differentiation from epileptiform activity of human hippocampal sharp wave ripples during NREM sleep”, Hippocampus. 2019 Nov 25. DOI: 10.1002/hipo.23183