A Screen-Peck Task for Investigating Cognitive Bias in Laying Hens.

Affect-induced cognitive judgement biases occur in both humans and animals. Animals in a more negative affective state tend to interpret ambiguous cues more negatively than animals in a more positive state and vice versa. Investigating animals' responses to ambiguous cues can therefore be used...

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Main Authors: Amanda Deakin, William J Browne, James J L Hodge, Elizabeth S Paul, Michael Mendl
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2016-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4943636?pdf=render
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author Amanda Deakin
William J Browne
James J L Hodge
Elizabeth S Paul
Michael Mendl
author_facet Amanda Deakin
William J Browne
James J L Hodge
Elizabeth S Paul
Michael Mendl
author_sort Amanda Deakin
collection DOAJ
description Affect-induced cognitive judgement biases occur in both humans and animals. Animals in a more negative affective state tend to interpret ambiguous cues more negatively than animals in a more positive state and vice versa. Investigating animals' responses to ambiguous cues can therefore be used as a proxy measure of affective state. We investigated laying hens' responses to ambiguous stimuli using a novel cognitive bias task. In the 'screen-peck' task, hens were trained to peck a high/low saturation orange circle presented on a computer screen (positive cue-P) to obtain a mealworm reward, and to not peck when the oppositely saturated orange circle was presented (negative cue-N) to avoid a one second air puff. Ambiguous cues were orange circles of intermediate saturation between the P and N cue (near-positive-NP; middle-M; near-negative-NN), and were unrewarded. Cue pecking showed a clear generalisation curve from P through NP, M, NN to N suggesting that hens were able to associate colour saturation with reward or punishment, and could discriminate between stimuli that were more or less similar to learnt cues. Across six test sessions, there was no evidence for extinction of pecking responses to ambiguous cues. We manipulated affective state by changing temperature during testing to either ~20°C or ~29°C in a repeated measures cross-over design. Hens have been shown to prefer temperatures in the higher range and hence we assumed that exposure to the higher temperature would induce a relatively positive affective state. Hens tested under warmer conditions were significantly more likely to peck the M probe than those tested at cooler temperatures suggesting that increased temperature in the ranges tested here may have some positive effect on hens, inducing a positive cognitive bias.
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spelling doaj.art-0c1d1e53a1894568b795931ccdf897ca2022-12-21T19:31:14ZengPublic Library of Science (PLoS)PLoS ONE1932-62032016-01-01117e015822210.1371/journal.pone.0158222A Screen-Peck Task for Investigating Cognitive Bias in Laying Hens.Amanda DeakinWilliam J BrowneJames J L HodgeElizabeth S PaulMichael MendlAffect-induced cognitive judgement biases occur in both humans and animals. Animals in a more negative affective state tend to interpret ambiguous cues more negatively than animals in a more positive state and vice versa. Investigating animals' responses to ambiguous cues can therefore be used as a proxy measure of affective state. We investigated laying hens' responses to ambiguous stimuli using a novel cognitive bias task. In the 'screen-peck' task, hens were trained to peck a high/low saturation orange circle presented on a computer screen (positive cue-P) to obtain a mealworm reward, and to not peck when the oppositely saturated orange circle was presented (negative cue-N) to avoid a one second air puff. Ambiguous cues were orange circles of intermediate saturation between the P and N cue (near-positive-NP; middle-M; near-negative-NN), and were unrewarded. Cue pecking showed a clear generalisation curve from P through NP, M, NN to N suggesting that hens were able to associate colour saturation with reward or punishment, and could discriminate between stimuli that were more or less similar to learnt cues. Across six test sessions, there was no evidence for extinction of pecking responses to ambiguous cues. We manipulated affective state by changing temperature during testing to either ~20°C or ~29°C in a repeated measures cross-over design. Hens have been shown to prefer temperatures in the higher range and hence we assumed that exposure to the higher temperature would induce a relatively positive affective state. Hens tested under warmer conditions were significantly more likely to peck the M probe than those tested at cooler temperatures suggesting that increased temperature in the ranges tested here may have some positive effect on hens, inducing a positive cognitive bias.http://europepmc.org/articles/PMC4943636?pdf=render
spellingShingle Amanda Deakin
William J Browne
James J L Hodge
Elizabeth S Paul
Michael Mendl
A Screen-Peck Task for Investigating Cognitive Bias in Laying Hens.
PLoS ONE
title A Screen-Peck Task for Investigating Cognitive Bias in Laying Hens.
title_full A Screen-Peck Task for Investigating Cognitive Bias in Laying Hens.
title_fullStr A Screen-Peck Task for Investigating Cognitive Bias in Laying Hens.
title_full_unstemmed A Screen-Peck Task for Investigating Cognitive Bias in Laying Hens.
title_short A Screen-Peck Task for Investigating Cognitive Bias in Laying Hens.
title_sort screen peck task for investigating cognitive bias in laying hens
url http://europepmc.org/articles/PMC4943636?pdf=render
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