FEB 26, 2018

Searching for "Normal" in Brain Function

WRITTEN BY: Brenda Kelley Kim

There are many assessments of health that have definite parameters. We know what blood pressure numbers should be, heart rate, weight, cholesterol levels and so many other indicators that have defined standards of what is normal.

The same is not entirely true of brain function. While researchers are always trying to find ways to understand and treat neurological illnesses, some of the newest information shows that there may not be a “normal” level for brain function.

Senior author of the work, clinical psychologist Avram Holmes of Yale University explained, "I would argue that there is no fixed normal. There's a level of variability in every one of our behaviors. Healthy variation is the raw material that natural selection feeds on, but there are plenty of reasons why evolution might not arrive at one isolated perfect version of a trait or behavior. Any behavior is neither solely negative or solely positive. There are potential benefits for both, depending on the context you're placed in.”

By looking at different neurological traits, the team sought to find out if specific characteristics that are normally thought of as negative, might be positive. One of these traits is impulsive sensation seeking, also known as being an adrenaline junkie. This trait often goes hand in hand with actions like risky sexual behavior, dangerous sports or recreational pursuits, drug abuse or criminal activity. However, when humans were first evolving, this trait could be helpful, because it would spur someone to take risks necessary to find food sources and safe shelter. In present day, however, there are careers that people who have this trait are well-suited for, such as stunt professionals in movies or a guide for high adventure trips.

Another trait that is considered a negative is anxiety. People who get anxious in some situations are seen as having a mental problem, but that feeling of dread is sometimes what causes behaviors that are beneficial. Students who have test anxiety usually study more for their exams. Those who fear social situations, prepare more if they have to speak publicly or are involved in sales or presentations. That bit of fear or nervousness might be the push that motivates a larger effort or better work habits.

So does that mean that no matter what the mental situation, everyone is healthy and no one has a disorder? Not at all says, Holmes. Disordered psychological function is a very real problem, but the way medical research has gone to date focuses on finding genetic markers and biological abnormalities that are associated with mental disorders and then try to find a way to treat or detect the illness. Holmes explains how that needs to change, including an understanding that no disorder is a result of just one cause. He wrote, “It may be the case that if you focus on a single phenotype, there isn't a specific line that separates health from disease, and that we must consider multiple phenotypes simultaneously.”

Holmes’ work is focused on developing ways to look at different traits of human behavior, not as separate issues but instead as combinations of phenotypes along a continuum. Solving the issues of mental health and brain function has to be a collaborative effort. In this information age, there is enough big data floating around to look at more than just single traits like anxiety or impulsiveness as being normal or abnormal, but that requires getting different researchers and institutions to work together, which can be difficult. It comes down to changing the outlook of society, says Holmes, "This is a broader issue with our society. But we're all striving towards some artificial, archetypal ideal, whether it's physical appearance or youthfulness or intelligence or personality. But we need to recognize the importance of variability, both in ourselves and in the people around us. Because it does serve an adaptive purpose in our lives."

Sources: Yale University via EurekAlert!, Cell Press, Geek