The influence of inter-trial behaviour on decision making

Abstract

Animals quickly learn to approach sources of food. Here, we characterize a form of behaviour in which rats made volitional orofacial contact with inactive feeders between trials of a self-paced operant task. This extraneous feeder sampling (EFS) was never reinforced and therefore imposed opportunity and effort costs. EFS decreased during initial training but persisted thereafter. The relative rate of EFS to operant responding increased with either novel changes to the operant chamber, or reward devaluation. We speculate this may function to increase exploration when the task is uncertain (early in learning or introduction of novel components), when the opportunity cost is low, or when the learned sensorimotor solution is compromised. Analysis of sex differences revealed females have a higher propensity for EFS, further supporting our speculations that EFS is rooted in exploratory systems. Preliminary results suggest the anterior cingulate cortex (ACC) is involved in the expression of this behaviour.