Evidence map›Paper›PMID 42568400›Full record

ArticleFrontiers in veterinary science2026

Balancing consistency and flexibility: exploring trait and state optimism in rats using the cognitive judgement bias test.

Louisa Bierbaum, Rebecca Anna Mainzer, Carolin Mundinger, Sylvia Kaiser, S Helene Richter

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

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

What it found

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

5 authors.

Louisa BierbaumDepartment of Behavioural Biology, University of Münster, Münster, Germany.
Rebecca Anna MainzerDepartment of Behavioural Biology, University of Münster, Münster, Germany.
Carolin MundingerDepartment of Behavioural Biology, University of Münster, Münster, Germany.
Sylvia KaiserDepartment of Behavioural Biology, University of Münster, Münster, Germany.
S Helene RichterDepartment of Behavioural Biology, University of Münster, Münster, Germany.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Optimistic or pessimistic interpretation of ambiguous information has been widely used in animal welfare science as an indicator of emotional states. Yet, growing evidence suggests that besides this state dimension, animals differ consistently in their optimism levels, suggesting a trait dimension of optimism, too. The boundary as well as a potential interplay between these two dimensions, however, remains poorly understood. Here, we aimed to disentangle consistent trait from transient state optimism using a spatial cognitive judgement bias test in laboratory rats. Specifically, we repeatedly tested individuals for their optimism levels and assessed the repeatability to infer trait optimism. Then, we exposed the rats to either negatively valenced 22 kHz or positively valenced 50 kHz USV playbacks to manipulate state optimism. Lastly, we conducted tests for anxiety-like behavior to assess whether the manipulation was accompanied by broader changes consistent with altered emotional state. Building on previous work, we found repeatable optimism levels over 3 weeks, supporting the existence of a trait dimension of optimism. Surprisingly, however, we did not detect any statistically significant effects of the USV playbacks on optimism levels and anxiety-like behavior, hindering the systematic investigation of a state dimension. Overall, our study provides further evidence that optimism has a consistent trait dimension, while highlighting the ongoing need for future research to successfully disentangle trait and state components of behavior.

Indexed as

animal personalitycognitive judgement biasoptimismratsspatial taskstatetraitultrasonic vocalizations

Identifiers

PMID42568400
PMCPMC13447164

What Socratic holds

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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 Socratic graph.