Brain activity (IMAGE) Johns Hopkins Medicine Caption Average brain activity during a working memory task in a group of healthy subjects as measured by fMRI. The colors represent higher brain activity in the carriers of the G version of the GCPII enzyme, where brains are less efficient at performing the task, compared with those carriers with the A version of the enzyme. Credit Bigos laboratory 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.