Habituation of exploratory activity to new stimuli, to the absence of a previously presented stimulus and to new contexts, in rats

Rats trained to run a shuttle-alleyway for food exhibited exploratory behaviour to a novel visual/tactual stimulus presented in a specific place of the alley. Intermittent presentation of the same stimulus in the same place resulted in reduction of the exploratory activity (habituation), both within and between sessions. The animals also directed exploratory activity to the absence of the previously presented stimulus at the place where the stimulus had been presented before; this latter response also habituated. The presentation (1) of the same stimulus to which the animals had already habituated in another place in the alleyway or when the animals were running in an opposite direction to the previous trials of stimulus presentation, or (2) of another stimulus, resulted, again, in the appearance of exploratory activity. These results lead to the conclusion that the animals code external events, store this information, and use it to detect spatial- and directional-contextual changes and to generate predictions about that specific environment.