Nicotine Diminishes Anger Response

Researchers at the University of California in Irvine (UCI) have recently conducted a scientific experiment aimed at understanding how people's anger response changes when they consume nicotine. The fact that smoking eases stress is well-known, but exactly how nicotine influences the brain has remained a mystery up until now. In their studies, the experts have looked at how individuals respond to anger stimuli when they have nicotine patches on, as opposed to a control group that has placebos.

The results have revealed that, even when taking just half a nicotine patch, participants have been less likely to react to challenges than those in the control group, who have been given patches with nothing on them. The researchers believe that this conclusion implies the fact that people who are easily angered or who live under increased amounts of stress are very likely to pick up smoking and to become more addicted than others. They may also find it harder to quit the habit than those less prone to getting angry all the time.

UCI psychiatry researcher Jean Gehricke, who has been part of the investigation team, said that, “Participants who showed nicotine-induced changes in anger task performance also showed changes in brain metabolism.” For the trials, the experts have designed a simple computer game, in which test subjects have been asked to compete against a nonexistent opponent, as in a computer software. The behavior of the opponent has been designed to irritate and provoke, and the goal of the exercise has been simple – to see who clicks first on a mouse button when seeing a red square on the computer screen.

The participants could also set punishments for those who have lost, in the form of a burst of noise in the headphones they have worn. The researchers have allowed each of the test subjects to see what punishment the fake opponent, which they have controlled, has been setting up for the people in the experiment. They have noticed that those who have been on the nicotine patch have been less likely to respond violently to challenges, and have not raised the severity of their punishment too much, in response to the fake moves of their opponents.

By analyzing the brains of participants with PET scans, the team has been able to determine that nicotine works on activating a brain region known as the limbic cortex, which has been previously associated with controlling emotions. When on the patch, test subjects' brains have showed increased signs of activity in this region, LiveScience reports, whereas those in the control group have displayed normal activity levels. Details of the experiments are published in this week's issue of the journal Behavioral and Brain Functions.