Decisions are best made when you are full. Researchers have found that the hormone ghrelin-released before meals and is known to increase appetite has a negative effect on both decision making and impulse control.
“For the first time, we have been able to show that increased levels of ghrelin seen before meals or during fasting, cause the brain to act impulsively and also affect the ability to make rational decisions,” he said one of the researchers Karolina Skibicka at the Sahlgrenska Academy, University of Gothenburg in Sweden.
When you’re hungry, ghrelin hormone is produced in the stomach. In the new study conducted in rats, the hormone has been shown to have a negative effect on the ability of decision making and impulse control.
Rats can be trained to be rewarded (with sugar) when executing an action such as pressing a lever ( “go”), or instead can be rewarded only when they are reluctant to press the lever ( “no-go”) when an appropriate signal is given.
They learn this repeatedly receiving a signal. For example, a flash of light or a buzzing sound that tells them what action should be executed for them to receive their reward.
An inability to withstand the pressure on the lever, when the “no-go” signal is given, is a sign of impulsivity.
The researchers found that the rats that received ghrelin directly into the brain; mimics the way the stomach warn us of the need to eat, they were more likely to press the lever instead of waiting, although causing them to lose their reward.
The highest levels of ghrelin prevented rats from being able to wait for the larger reward.