Study
Wake-like skin patterning and neural activity during octopus sleep
Pophale, Aditi; Shimizu, Kazumichi; Mano, Tomoyuki; Reiter, Sam
Nature, 2023
High-resolution filming of skin patterns was combined with recording of brain activity during sleep, so that surface behaviour and neural state could be compared directly.
- Studied in
- Octopus laqueus
- Sample size
- small number of individuals with simultaneous imaging and recording
During active sleep, octopuses cycled through skin patterns they also produce while awake, and brain activity resembled waking patterns rather than quiet sleep.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Active sleep in octopuses involves wake-like neural dynamics, consistent with a role in memory consolidation.
How NatureHQ reads it
This closes part of the gap the 2021 study left open: the active phase is not just twitching, the brain is doing something wake-like. It still cannot show that an octopus experiences a dream. The most defensible summary is that octopuses have a sleep state with the neural and behavioural signature of REM sleep, and that what it is like from the inside is unknown.
- Small sample, as is normal for this technique.
- A different species again from the 2021 work.
- Neural resemblance to waking does not establish subjective content.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Nature PortfolioPublished in a Nature Portfolio journal.
doi.org/10.1038/s41586-023-06203-4
This reference was resolved automatically against Crossref and OpenAlex on 2026-08-11.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-09.