Delay discounting task in pigs reveals response strategies related to dopamine metabolite

摘要: We developed a novel delay discounting task to investigate outcome impulsivity in pigs. As can affect aggression, and might also relate proactive reactive coping styles, eight (HR) (LR) pigs identified manual restraint test ("Backtest", after Bolhuis et al., 2003) were weaned mixed four pens of unfamiliar pigs, so that each pen had two HR LR aggression was scored the 9h mixing. In task, pig chose between levers, one always delivering small immediate reward, other large delayed reward with daily increasing delays, impulsive individuals being ones value quicker. Two strategies emerged: some gradually switched their preference towards ('Switchers') as predicted, but others persistently preferred until they stopped making choices ('Omitters'). Outcome itself unrelated these strategies, urinary serotonin metabolite (5-HIAA) or dopamine (HVA) levels, at weaning, style. However, HVA relatively higher Omitters than Switchers, positively correlated behavioural measures indecisiveness frustration during choosing. The thus revealed response seemed be related activity system indicate difference execution, rather outcome, impulsivity.