Susceptibility to auditory closed-loop stimulation of sleep slow oscillations changes with age

Jules Schneider; Penelope A Lewis; Dominik Koester; Jan Born; Hong-Viet V Ngo

doi:10.1093/sleep/zsaa111

Susceptibility to auditory closed-loop stimulation of sleep slow oscillations changes with age

Sleep. 2020 Dec 14;43(12):zsaa111. doi: 10.1093/sleep/zsaa111.

Authors

Jules Schneider^{1

2

3}, Penelope A Lewis^{1

2}, Dominik Koester⁴, Jan Born^{4

5}, Hong-Viet V Ngo^{4

6}

Affiliations

¹ School of Biological Sciences, University of Manchester, Manchester, UK.
² School of Psychology, Cardiff University, Cardiff, UK.
³ Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
⁴ Institute for Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany.
⁵ Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany.
⁶ Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands.

Abstract

Study objectives: Cortical slow oscillations (SOs) and thalamocortical sleep spindles hallmark slow wave sleep and facilitate memory consolidation, both of which are reduced with age. Experiments utilizing auditory closed-loop stimulation to enhance these oscillations showed great potential in young and older subjects. However, the magnitude of responses has yet to be compared between these age groups. We examined the possibility of enhancing SOs and performance on different memory tasks in a healthy middle-aged population using this stimulation and contrast effects to younger adults.

Methods: In a within-subject design, 17 subjects (55.7 ± 1.0 years) received auditory stimulation in synchrony with SO up-states, which was compared to a no-stimulation sham condition. Overnight memory consolidation was assessed for declarative word-pairs and procedural finger-tapping skill. Post-sleep encoding capabilities were tested with a picture recognition task. Electrophysiological effects of stimulation were compared to a previous younger cohort (n = 11, 24.2 ± 0.9 years).

Results: Overnight retention and post-sleep encoding performance of the older cohort revealed no beneficial effect of stimulation, which contrasts with the enhancing effect the same stimulation protocol had in our younger cohort. Auditory stimulation prolonged endogenous SO trains and induced sleep spindles phase-locked to SO up-states in the older population. However, responses were markedly reduced compared to younger subjects. Additionally, the temporal dynamics of stimulation effects on SOs and spindles differed between age groups.

Conclusions: Our findings suggest that the susceptibility to auditory stimulation during sleep drastically changes with age and reveal the difficulties of translating a functional protocol from younger to older populations.

Keywords: ageing; auditory closed-loop stimulation; memory; sleep; sleep spindles; slow oscillations.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acoustic Stimulation
Adult
Electroencephalography
Humans
Memory Consolidation*
Middle Aged
Sleep
Sleep, Slow-Wave*

Abstract

Publication types

MeSH terms

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