Sex differences in object recognition are modulated by object similarity

How females and males differ in performance in object recognition tasks appears to vary among mammalian species, with female superiority found in the laboratory rat and humans but not in the laboratory mouse. Here we assessed sex differences in object recognition in C57BL/J6 mice by varying the similarity between objects to be learned. Females outperformed males in object recognition when the novel object was similar to a previously learned object.

► Sex differences in object recognition in mice as a function of object similarity.
► Female mice are highly sensitive to differences between objects.
► Male mice show a higher threshold for detecting novelty than do females.
► Sex differences in object recognition are modulated by object similarity.