Uncertainty in Reward Timing Increases the Effect of Serotonin Promoting Waiting (image) Okinawa Institute of Science and Technology (OIST) Graduate University Share Print E-Mail Caption In a test where food rewards were always delivered after 6 seconds, serotonin's effect of extending nose-poke time was small (left). But in tests where food goes was delivered after two, six, or ten seconds later, serotonin boosted nose poke times significantly (right). Credit OIST Usage Restrictions None Share Print E-Mail 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.