| Reference code: | PT/FB/BL-2020-391.05 |
| Location: | BF-GMS
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Title:
| How does closing one’s ‘dream’ eyes affect alpha power and visual content in lucid REM sleep?
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| Publication year: | 2024
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URL:
| https://doi.org/10.1016/j.sleep.2023.11.136
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| Abstract/Results: | ABSTRACT:
Introduction: When asleep, we experience strong visual imagery (a.k.a. dreams) in the absence of external stimuli and although our physical eyes are closed. During wake, closing one's eyes is robustly accompanied by the appearance of EEG alpha oscillations. We aim to test whether this fundamental property of the waking visual system is maintained during REM sleep and whether it is associated with dream visual content.
To do so, we took advantage of the unique peculiarities of lucid dreamers, who are aware of dreaming during REM sleep, can perform a predefined task while dreaming and even signal it via muscular codes, allowing to timestamp the EEG segment corresponding to a dream of interest.
Materials and Methods: We recruited 4 lucid dreamers with narcolepsy, based on their ability to easily reach lucid REM sleep in a laboratory setting. Each participant had five 40-min naps monitored by polysomnography. We instructed participants to: i) successively close and open their eyes in their dreams and sniff twice for ‘close’ and once for ‘open’ (measured by a nasal cannula); ii) report whether they had a visual content or not in both conditions by smiling (‘yes’, zygomatic EMG) or frowning (‘no’, corrugator EMG). We woke participants up when they transitioned from REM sleep to NREM sleep stage 2 and immediately collected a dream report.
We used spectral power analysis in the 5 s window after a response code (sniff or facial EMG) to determine whether occipital alpha power during (lucid) REM sleep varies when the dreamer’s eyes are open or closed and in function of the presence or absence of visual content.
Results: Lucid dreamers with narcolepsy reached REM sleep in 21/26 naps and were lucid in 8 of these naps. In total, they were able to perform a closed eyes signal 29 times and an open eyes signal 19 times.Surprisingly, eyes’ closure during dreams was not always accompanied with a loss of visual content (6/16 cases without visual content vs. 10/16 cases with visual content; no visual code for the remaining 13 closed eyes signals). Conversely, participants always reported visual content when their eyes were open (8/8; no visual code for the remaining 11 eyes closed signal). All isolated closed/open signals without information on the visual content were excluded from the spectral power analysis.
In our preliminary results, we found no main effect of eyes condition (closed vs. open), of the visual content condition (no visual vs. visual content), or their interaction on the occipital alpha band power.
Conclusions: Closing our eyes in dreams does not seem to prevent the occurrence of visual content or to reliably increase occipital alpha power as it is the case during wakefulness. However, our results have to be confirmed with a larger sample size.
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| Accessibility: | Document exists in file
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Copyright/Reproduction:
| By permission
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Language:
| eng
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Author:
| Al-Youssef, S.
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Secondary author(s):
| Konkoly, K., Arnulf, I., Paller, K., Oudiette, D.
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Document type:
| Conference abstract
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Number of reproductions:
| 1
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Reference:
| Al-Youssef, S., Konkoly, K., Arnulf, I., Paller, K., & Oudiette, D. (2024). How does closing one’s ‘dream’ eyes affect alpha power and visual content in lucid REM sleep? Sleep Medicine, 115(Supplement 1), S36. https://doi.org/10.1016/j.sleep.2023.11.136
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| Indexed document: | No
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| Keywords: | Lucid REM sleep / Alpha power / EEG / Visual content
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