Female rats take longer than male rats to update reward expectancies when outcomes are worse than expected.

The ability to update predictive relationships and adjust behavior accordingly is critical for survival. Females take longer to update expectancies under conditions of outcome omission. It remains unknown whether that is also the case under conditions when outcomes are delivered such as in overexpectation. Here we examined whether male and female rats are able to learn from overexpectation using the same learning parameters. Our data show that males but not females learn from overexpectation when given just a single day of compound training, whereas both sexes learn when given extended 2 days of overexpectation training. These data provide important insight into sex differences that link with prior work and thus open an avenue for the study of how conflicting memories interact in the male and female brain. (PsycInfo Database Record (c) 2020 APA, all rights reserved).