Behavioural and Physiological Effects of Finely Balanced Decision-Making in Chickens
2014 (English)In: PLoS ONE, ISSN 1932-6203, Vol. 9, no 10, e108809- p.Article in journal (Refereed) Published
In humans, more difficult decisions result in behavioural and physiological changes suggestive of increased arousal, butlittle is known about the effect of decision difficulty in other species. A difficult decision can have a number ofcharacteristics; we aimed to monitor how finely balanced decisions, compared to unbalanced ones, affected the behaviourand physiology of chickens. An unbalanced decision was one in which the two options were of unequal net value (1 (Q1) vs.6 (Q6) pieces of sweetcorn with no cost associated with either option); a finely balanced decision was one in which theoptions were of equal net value (i.e. hens were "indifferent" to both options). To identify hens’ indifference, a titrationprocedure was used in which a cost (electromagnetic weight on an access door) was applied to the Q6 option, to find theindividual point at which hens chose this option approximately equally to Q1 via a non-weighted door. We then comparedbehavioural and physiological indicators of arousal (head movements, latency to choose, heart-rate variability and surfacebody temperature) when chickens made decisions that were unbalanced or finely balanced. Significant physiological (heartratevariability) and behavioural (latency to pen) differences were found between the finely balanced and balancedconditions, but these were likely to be artefacts of the greater time and effort required to push through the weighted doors.No other behavioural and physiological measures were significantly different between the decision categories. We suggestthat more information is needed on when best to monitor likely changes in arousal during decision-making and that futurestudies should consider decisions defined as difficult in other ways.
Place, publisher, year, edition, pages
Public Library of Science , 2014. Vol. 9, no 10, e108809- p.
IdentifiersURN: urn:nbn:se:liu:diva-111660DOI: 10.1371/journal.pone.0108809ISI: 000342591500033PubMedID: 25275440OAI: oai:DiVA.org:liu-111660DiVA: diva2:758736