title: Cognitive bias, hand preference and welfare of common marmosets.
abstract: Common marmosets (Callithrix jacchus) have hand preferences for grasping pieces of food and holding them while eating and these are stable throughout adult life. We report here that left-handed marmosets have negative cognitive bias compared to right-handed marmosets. Twelve marmosets were trained to expect a food reward from a bowl with a black lid and not from one with a white lid, or vice versa. In probe tests with ambiguous, grey-lidded bowls a left-handed group (N=7) were less likely to remove the lid to inspect the bowl than a right-handed group (N=5). This difference between left- and right-handed marmosets was not dependent on rate of learning, sex or age. In fact, hand-preference was not associated with rate of learning the task. Furthermore, retrospective examination of colony records of 39 marmosets revealed that more aggression was directed towards left- than right-handed marmosets. Hence, hand preference, which can be measured easily, could serve as an indicator of cognitive bias and may signal a need for particular care in laboratory environments. We explain the results by arguing that hand preference reflects more frequent (or dominant) use of the opposite hemisphere and this predisposes individuals to behave differently.
authors: Centre for Neuroscience and Animal Behaviour, School of Science and Technology, University of New England, Armidale, NSW 2351, Australia.
authors: Dianne J
authors: DJ
authors: Gordon
authors: Centre for Neuroscience and Animal Behaviour, School of Science and Technology, University of New England, Armidale, NSW 2351, Australia. Electronic address: lrogers@une.edu.au.
authors: Lesley J
authors: LJ
authors: Rogers
mesh_terms: D000374:Aggression; D000375:Aging / Q000523:psychology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002144:Callithrix / Q000523:psychology*; D003071:Cognition; D005260:Female; D005502:Food; D007839:Functional Laterality; D006225:Hand; D007858:Learning; D008297:Male; D011581:Psychological Tests; D012189:Retrospective Studies; D012201:Reward; D012727:Sex Characteristics; D014947:Wounds and Injuries
chemical_list: D000900:Anti-Bacterial Agents
keywords: Ambiguous stimulus; Cognitive bias; Common marmoset; Hand preference; Hemispheric dominance; Welfare