Intrinsic timescales of spiking activity in humans during wakefulness and sleep

Abstract

Information processing in the brain requires integration of information over time.Such an integration can be achieved if signals are maintained in the network activity for the required period, as quantified by the intrinsic timescale. While short timescales are considered beneficial for fast responses to stimuli, long timescales facilitate information storage and integration. We quantified intrinsic timescales from spiking activity in the medial temporal lobe of humans. We found extended and highly diverse timescales ranging from tens to hundreds of milliseconds, though with no evidence for differences between subareas. Notably, however, timescales differed between sleep stages and were longest during slow wave sleep. This supports the hypothesis that intrinsic timescales are a central mechanism to tune networks to the requirements of different tasks and cognitive states.

The Temporal Dynamics of Aperiodic Neural Activity Track Changes in Sleep Architecture

“…Based on this interpretation, N3 was found to have the lowest knee frequency, and as such would be interpreted as having the longest processing time, whereas REM sleep and wakefulness were found to have higher knee frequencies, and as such, faster processing timescales. These findings are consistent with other work that has examined aperiodic knees in sleep data (Lendner et al, 2023), autocorrelation analyses of sleep data (Zilio et al, 2021), as well as an analysis of timescales during sleep estimated from spiking activity (Hagemann et al, 2022).…”