Just in time for back-to-school season, researchers have turned procrastinating monkeys into workaholics by suppressing a gene that encodes a receptor for a key brain chemical.
The receptor, for the neurotransmitter dopamine, is important for reward learning. By suppressing it, researchers at the US National Institute of Mental Health (NIMH) in Bethesda, Maryland caused monkeys to lose their sense of balance between reward and the work required to get it.
“Like many of us, monkeys normally slack off initially in working toward a distant goal. They work more efficiently—make fewer errors—as they get closer to being rewarded,” says Barry Richmond of the NIMH Laboratory of Neuropsychology. “But without the dopamine receptor, they consistently stayed on-task and made few errors, because they could no longer learn to use visual cues to predict how their work was going to get them a reward.”