There is nothing that changes your regular routine more than Christmas. From cooking a turkey – a feat you haven’t tried from one end of the year to the other – to entertaining guests you only see a few times a year. This disruption to what it knows best is the worst thing for the psyche. What the psyche loves more than anything though is to be rewarded and there is nothing more rewarding than giving someone that ideal present.
Dopamine is a neurotransmitter that is associated with the pleasure system of the brain. It provides feelings of enjoyment and reinforcement which motivate people to perform certain activities. For this reason, more than 50 years of research has gone into studying the possible links between dopamine and reward.
A textbook definition of reward is that it is the activity of neural circuits that function to maintain an animal’s contact with certain environmental stimuli, either now or in the future. By this reasoning, there must be something about the activity that the animal perceives to be pleasant. In 1954, Olds and Milner discovered that a rat would press a bar repeatedly to administer brief bursts of electrical stimulation to specific sites in the brain, a phenomenon known as intracranial self-stimulation, or brain-stimulation reward. In 1966, Wise explained this by stating that brain stimulation must be activating the system underlying reward. After almost 50 years of research, it was found that this is where dopamine comes in.
Stimulation to parts of the brain such as the lateral hypothalamus and the medial forebrain bundle activate the mesolimbic dopamine pathway, sending dopamine-containing terminals to various sites in the brain, such as the nucleus acumbens, a collection of neurons thought to play a role in reward, laughter, and other positive feelings.
There are several reasons for believing that this pathway is involved in the sensation of reward. For one, there is a marked increase in dopamine release when animals are engaged in intracranial stimulation. Also, the amount of dopamine released seems to somehow determine how rewarding an event is. As well as this, actions such as feeding, sexual activity or highly addictive drugs such as nicotine and cocaine, prove to increase the level of dopamine found in the nucleus acumbens.
All of this goes to show that there must be an important link between dopamine and reward. Like the rats pressing the bar, giving gifts has no obvious positive effect on our fitness or wellbeing. Gifts are not usually given so that the giver will get one in return. So there must be something about gift giving that the giver enjoys.
Giving presents is a brain-stimulation reward event that sets dopamine neurons firing and makes you feel happy. So there’s something to think about next Christmas or indeed any time when it all gets a bit much – give someone a present!
