Primate Brain (IMAGE) KU Leuven Caption The researchers temporarily switched off the connection between the ventral tegmental area (VTA) and the nucleus accumbens (NAc). As a result, the monkeys' motivation to work harder for a bigger reward decreased. Credit Wim Vanduffel et al. (2020) 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.