Wearing an eye mask during overnight sleep improves episodic learning and alertness

Abstract

Ambient light can influence sleep structure and timing. We explored how wearing an eye-mask to block light during overnight sleep impacts on memory and alertness, changes that could benefit everyday tasks like studying or driving. In Experiment 1, ninety-four 18–35-year-olds wore an eye-mask while they slept every night for a week and underwent a control condition in which light was not blocked for another week. Five habituation nights were followed by a cognitive battery on the sixth and seventh days. This revealed superior episodic encoding and an improvement on alertness when using the mask. In Experiment 2, thirty-five 18–35-year-olds used a wearable device to monitor sleep with and without the mask. This replicated the encoding benefit and showed that it was predicted by time spent in slow wave sleep. Our findings suggest that wearing an eye-mask during overnight sleep can improve episodic encoding and alertness the next day.

No clear or consistent evidence that wearing an eye mask leads to meaningful improvement in learning and alertness: a reanalysis of Greco et al. (2023)

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1 It is interesting to note that a similar overnight change analysis is presented for the motor skill learning task in the supplement but the main article reports an analysis in which the interaction of condition and day was tested for this outcome.

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“…Greco et al [1] , in the "Statement of significance" section, claim that their findings suggest that "[. .…”

“…However, these conditions did not differ in terms of an 'absolute consolidation' score, which was the difference in performance between days 6 and 7 (reported in the supplement). 1 It is not clear why the day 6 and 7 results were separated, as performance on the PAL task could have been assessed via a single model. Indeed a single model analysis is preferable if the difference between immediate and delayed recall is of interest.…”