Superimposition of the cortex of a shrew (IMAGE) Proceedings of the National Academy of Sciences Caption Superimposition of the cortex of a shrew imaged in winter (blue) and summer (orange) shows that cortex volume decreases in winter (mostly orange, indicating a larger summer cortex) Credit Image credit: Saikat Ray Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.