Memory for feeding in rats' spatial and visual choice behaviour

Four experiments with mazes examined the effects of feeding upon rats' subsequent choice between spatially or visually distinct alternatives. It is concluded that rats can recall both whether any food remained at the cessation of feeding (nondepletion) and whether or not feeding was interrupted; both features can be associated with the place where they occurred. The memory of nondepleted food evokes an unlearned tendency to return to the place where it was present (“win-stay” behaviour). The memory of interruption transiently had a similar effect in naive animals but eventually exerts a more nonspecific influence, which facilitates not only win-stay learning but its opposite, win-shift. The nondepletion effect was also obtained when the alternatives were defined by a visual cue (brightness) rather than spatial location. The determinants of staying and shifting are discussed in terms of reward memory and exploration.