Do animals dream?

Malinowski, Josie E.; Scheel, David; McCloskey, Michael

doi:10.1016/j.concog.2021.103214

Cited by 4 publications

(4 citation statements)

References 95 publications

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“…For the behaviors we observed to be interpreted as possible dream-enactment, there would need to be some ecological relevance to the sequence of behaviors we observed to the waking life of this octopus (Malinowski et al, 2021). In keeping with this, the behaviors we observed are consistent with the waking activity of octopuses in choice secondary defense behaviors outlined by Hanlon and Messenger (2008), where they describe the hierarchical structure cephalopods employ in deciding how to respond to threats.…”

Section: Discussionsupporting

confidence: 79%

“…Cameras positioned on both sides of the tank would help to reduce out-of-sight periods when an octopus can be obscured by objects in its enclosure (e.g., PVC tubes, rocks). Tests of dream-enactment in captive octopuses could involve cognitive experiments focused on memory and learning and the development of underwater electroencephalogram sensors to identify if active sleep and other sleep stages reflect waking neural activity and body patterns (Malinowski et al, 2021). If detected in captivity as in our case, detailed necropsies of afflicted individuals are needed to identify possible linkages of these behaviors to neurological damage or disorders.…”

Section: Discussionmentioning

confidence: 99%

“…Cephalopod camouflage offers a unique way to access outputs of internal states inaccessible from other non-camouflaging species. Recently Malinowski et al (2021) conjectured that the characteristic sequences of camouflage changes occurring during episodes of active sleep in a specimen of O. cyanea appear to have a narrative structure that follows a sequence of natural behaviors. The authors argue that these behaviors may represent dream-enactment in cephalopods, in which the dreamer actively acts out dream actions, driven by the possible linkages between their waking and sleep behaviors (Malinowski et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

“…Recently Malinowski et al (2021) conjectured that the characteristic sequences of camouflage changes occurring during episodes of active sleep in a specimen of O. cyanea appear to have a narrative structure that follows a sequence of natural behaviors. The authors argue that these behaviors may represent dream-enactment in cephalopods, in which the dreamer actively acts out dream actions, driven by the possible linkages between their waking and sleep behaviors (Malinowski et al, 2021). They also argue that in the active sleep states, motor responses and body pattern displays are only partially suppressed.…”

Section: Introductionmentioning

confidence: 99%

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Abnormal behavioral episodes associated with sleep and quiescence in Octopusinsularis: Possible nightmares in a cephalopod?

Ramos,

Steinblatt,

Demsey

et al. 2023

Preprint

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This paper presents some unusual behaviors observed in one single specimen of O. insularis. While nothing can be concluded rigorously from such data, we share the data and our analysis with the community, in the hope that others will be on the lookout for such rare events. Sleep is a fundamental biological function that is present in all tested vertebrates and most invertebrates. Cephalopods, such as octopuses, are cognitively complex animals that display active and inactive sleep states similar to those of vertebrates. In particular, octopuses have active sleep states during which they display sequences of camouflage patterns and modulation of basal rhythms, while remaining relatively unresponsive to outside stimuli. Some scientists have speculated that these states could be analogous to dreaming in mammals, involving episodic recall with a narrative structure. The convergent evolution of sleep in neurologically complex animals is a striking possibility, but its demonstration requires overcoming significant challenges. Towards this end, capturing abnormal sleep-associated episodes and other parasomnias in cephalopods can provide further insight into the biology of their sleep. This study reports abnormal behavioral episodes associated with transitions between activity states and sleep states observed in a male Octopus insularis. The study used continuous video monitoring to characterize the animal's activity patterns and detect rare behavioral episodes. Over the course of a month, four brief episodes (duration range: 44-290 seconds) were identified during which the octopus abruptly emerged from quiescent or active sleep, detached itself from its sleep position, and engaged in antipredator and predatory behaviors (with no predator present). The longest of these episodes resembled the species-typical response to a predatory attack, suggesting that the animal may have been responding to a negative episodic memory or exhibiting a form of parasomnia. These findings, in conjunction with recent evidence for sleep in octopuses, highlight the complexity of possible sleep-associated behavioral episodes. Investigating sleep in invertebrates is crucial to understanding the evolution of sleep across distantly related species.

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Section: Discussionsupporting

confidence: 79%

Section: Discussionmentioning

confidence: 99%