It’s no surprise that mood affects how people view the world. But just how much it affects it may surprise you. A close look at the brain in action suggests that people who are in a good mood see the world as though they are looking through a much larger window than people in a negative mood do. They also take in more information.

Researchers at the University of Toronto looked at what parts of the brain were most active in people of differing mood. Using a technique called functional magnetic resonance imaging (FMRI), they saw that people in a good mood were using parts of the brain that those in a bad mood were not.

FMRI measures temporary changes in blood oxygen. When an area of the brain is active, it begins to use up the oxygen in the local blood supply. This is quickly followed by a rush of fresh oxygenated blood into that region. So a decrease in blood oxygenation quickly followed by an increase is taken to mean high activity in a particular region of the brain.

Subjects were shown a series of images designed to place them in a good, neutral or bad mood. They were then shown an image with a central face surrounded by a place, such as a house. After being asked about the gender of the face, to get them to focus in on it, their FMRIs were analyzed.

People in a good mood showed activity in an area of the brain called the parahippocampal place area (PPA), an area known to be involved in processing visual information about locations. This wasn’t seen in people who were in a bad mood; they appeared to be focused only on the face itself, not on the place in the background.

Credit: Image courtesy of University of Toronto

This seems to be saying that people in a good mood are looking at the big picture, or at least trying to. People in a bad mood are much more narrowly focused.

This could have a number of different applications in daily life. It suggests that you shouldn’t be doing activities that require you to be very observant when in a bad mood. Nor are you likely to be at your creative best.

On the other hand, a bad mood may be best suited to tasks that require a narrow focus, like knitting, sanding a floor, sorting through a sock drawer or filling out your taxes.

Optimists would say that this is another example of the power of positive thinking. Pessimists would like to see further studies.

The study appears in the June 3, 2009 issue of the Journal of Neuroscience.