Evidence map›Paper›PMID 42555601›Full record

ArticlePloS one2026

Automated sleep scoring in hibernating and non-hibernating American black bears.

Øivind Tøien, Elsa Cecile Pittaras, Yi-Ge Huang, Paul J N Brodersen, Giancarlo Allocca, Brian M Barnes, H Craig Heller

Abstract read
In one paragraph

Article in PloS one, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
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0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

7 authors.

Øivind TøienInstitute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America.ORCID https://orcid.org/0000-0001-5967-2483
Elsa Cecile PittarasDepartment of Biology, Stanford University, Stanford, California, United States of America.ORCID https://orcid.org/0000-0002-4048-9504
Yi-Ge HuangRadcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
Paul J N BrodersenDepartment of Pharmacology, University of Oxford, Oxford, United Kingdom.
Giancarlo AlloccaFlorey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia.
Brian M BarnesInstitute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America.
H Craig HellerDepartment of Biology, Stanford University, Stanford, California, United States of America.

Funding

The Administrative CoreP20GM103395 · NIGMS · UNIVERSITY OF ALASKA FAIRBANKS · PI BRIAN M BARNES · 2012 to 2026
$66.1M
Renovation of LARS for Arctic Ground Squirrel BreedingP20GM130443 · NIGMS · UNIVERSITY OF ALASKA FAIRBANKS · PI Maegan M Weltzin · 2019 to 2026
$16.4M
NIGMS NIH HHS P20 GM103395NIGMS NIH HHS P20 GM130443
6 · The paper itself

Abstract

Hibernating bears show remarkable metabolic suppression. Their decline in core body temperature (Tb) is moderate (from 38°C to 30-35°C), but their metabolism declines as much as 75%. To understand the role of sleep in this hypometabolic state, we recorded biotelemetrically EEG, EOG and EMG data over 3500 days from 16 captive American black bears in and out of hibernation under semi-natural conditions. This data set is too large to score manually for Wake, REM- and NREM sleep, so we tested two machine learning classifiers: (1) Somnotate trained on multiple one-day recordings, and (2) Somnivore, trained on a small subset from each recording. As automated scoring methods have not been applied to hibernating species before, a major concern is the effect changing brain temperature has on the EEG and on the machine learning based detection. Therefore, we selected reference data using consensus by 3 manual sleep scorers from each of 6 bears, two one-day recordings at the highest and lowest body temperatures during hibernation when Tb was oscillating in multiday cycles, and a non-hibernating one-day recording in summer. Somnotate results were excellent when trained separately for hibernating and non-hibernating data. Training Somnotate separately for high and low Tb within hibernation did not improve results further. Sleep times in hibernation were about 2x that in summer for both automated scores and manual scores (p < 0.0001). There were no significant differences in occupancy of vigilance states between automated and manual scores in hibernation (p > 0.05), but a small overestimate of sleep time in summer (p < 0.05). Both applications yielded F-measures against manual scores in the 0.90-0.98 range. Outliers in the 0.67-0.88 range were correlated between the two applications, indicating that specific files are more challenging to annotate. We conclude that both applications have accuracies approaching that of manual scorers when trained on high quality data.

Indexed as

HibernationSleepUrsidaeAnimalsBody TemperatureElectroencephalographyElectromyographyFemaleMachine LearningMale

Identifiers

PMID42555601
PMCPMC13440796

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.