Sex differences in rats' stationary exploration as a function of stimulus and environmental novelty

Abstract

Stationary visual scanning and sniffing of novel stimuli were measured using a head-poke response to supplement existing equivocal data on sex differences in exploration. With a short exposure to a novel apparatus, males and females showed a similar frequency of exploratory bouts, but the bouts were longer in females, showing that the sex difference is independent of a simple activity difference. With longer exposure, the difference was reversed, with males "compensating" for their initially lower level. Following familiarization to the apparatus, the sexes did not differ in exploration of an introduced novel stimulus. These results are consistent with males being more susceptible to inhibitory influences, such as disturbance and extreme novelty. Differences in within-trial changes in the level of exploration of a novel stimulus in novel and familiar environments were also observed. © 1977 Psychonomic Society, Inc.