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Lookup NU author(s): Olga Procenko, Professor Jenny ReadORCiD, Dr Vivek Nityananda
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Emotion-like states in animals are commonly assessed using judgment bias tests that measure judgements of ambiguous cues. Some studies have used these tests to argue for emotion-like states in insects. However, most of these results could have other explanations, including changes in motivation and attention. To control for these explanations, we developed a novel judgment bias test, requiring bumblebees to make an active choice indicating their interpretation of ambiguous stimuli. Bumblebees were trained to associate high or low rewards, in two different reward chambers, with distinct colours. We subsequently presented bees with ambiguous colours between the two learnt colours. In response, physically stressed bees were less likely than control bees to enter the reward chamber associated with high reward. Signal detection and drift diffusion models showed that stressed bees were more likely to choose low reward locations in response to ambiguous cues. The signal detection model further showed that the behaviour of stressed bees was explained by a reduction in the estimated probability of high rewards. We thus provide strong evidence for judgement biases in bees and suggest that their stress-induced behaviour is explained by reduced expectation of higher rewards, as expected for a pessimistic judgement bias.
Author(s): Procenko O, Read JCA, Nityananda V
Publication type: Article
Publication status: Published
Journal: Proceedings of the Royal Society B: Biological Sciences
Year: 2024
Volume: 291
Issue: 2032
Print publication date: 01/10/2024
Online publication date: 09/10/2024
Acceptance date: 13/08/2024
Date deposited: 13/08/2024
ISSN (print): 0962-8452
ISSN (electronic): 1471-2954
Publisher: The Royal Society Publishing
URL: https://doi.org/10.1098/rspb.2024.0512
DOI: 10.1098/rspb.2024.0512
Data Access Statement: All relevant data and code used for analysis to support this paper are available as electronic supplementary material
PubMed id: 39378898
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