Some people are more impulsive than others but impulsivity affects everyone to some degree. There are two types of impulsivity: the inability to stop yourself doing something (impulsive action) and the inability to delay gratification (impulsive choice). Now a new study has shown that a hormone involved in hunger can have a big impact on your decision making.
The hormone in question is called ghrelin and it is released when the stomach is empty. When your stomach is full, ghrelin is no longer released. The function of ghrelin is twofold in that it works on the hypothalamus to produce feelings of hunger and it also prepares the body for food. However, the role of ghrelin has been shown to extend beyond hunger and these researchers wanted to examine its role in impulsive behaviour.
=Q=
To do this, the researchers trained rats to perform tasks that would allow them to measure impulsive behaviour. The first of these was a “go/no-go” test which involved the rats either pressing a lever to get a reward (“go”) or being rewarded for not pressing a lever (“no-go”), dependent on an auditory signal. In a second experiment, rats were provided with a food pellet reward only if they could withhold their response for a set period of time. In the third experiment, rats were given the option of two levers, one of which would present one food pellet as soon as it was pressed while the other would present four food pellets but only after a significant delay.
It was found that when their ghrelin levels were high the rats were three times more likely to press the no-go lever and just a short period of fasting was enough to induce this response.
The researchers say this indicates that ghrelin makes you more likely to make impulsive decisions. Mind you, given that the decisions the rats were making related to food, it might be that it will only impact your food- or appetite-related decisions. Further research is required but in the meantime it might be an idea to avoid buying a house when you’re hungry.
