Attention and habituation: odor preferences, long-term memory, and multiple sensory cues of novel stimuli.

Investigation of and habituation to novel stimuli are part of exploratory behavior of rodents. They are necessary for assessing the environment in seeking food and sexual partners and in avoiding predators. Male and female gerbils were tested in the stimulus-elicited investigation paradigm in order to address several questions on three issues: (a) Gerbils initially showed preferences for odors of strange male bedding and for odors of home cage bedding and then habituated. There was no preference between these two odors, although they could be discriminated. The complex odor stimulus elicited more response than any of the components tested. (b) Memory of an object or of an odor was demonstrated up to 4 wk later. (c) Sensory deprivation by blinding, anosmizing, or removing somatosensation of the upper snout made only small differences in investigation. The removal of any two of these sensory inputs produced more interference with the response, but all of the gerbils investigated the stimulus. It is concluded that attention to novelty and habituation after repeated exposure are very robust behaviors and are mediated through multiple sensory channels.