The Hemispheres Myths

Dragoş Cîrneci                                     15 may 2011

We often listen to people talking about the fact that they are using their right hemisphere more than they use their left hemisphere or the other way around. Usually, the most “emotional” of them declare themselves users of the right hemisphere and the “rational” ones, the left hemisphere. Also, we sometimes hear reproaches saying that "Somebody does not use his full potential." We immediately think of the percentage of the brain a normal person activates (the numbers vary, some say it is 9%, others say it is 5% etc.). But is this how the things really are? Is it really true that the right hemisphere is responsible with emotions and the left one with reason? And should we learn how to activate our entire brain in order to perform better or even become geniuses?

The left or right? In the last couple of years new technologies were developed in order to help us observ what is happening in the brain while we are performing various tasks. Including the times when we get emotional or when we are reasoning. And surprise! It is discovered that the two hemispheres are both equally “emotional” and “rational”. For example, the right hemisphere manages math and new problems solving so we can say it is “rational” and the left hemisphere handles emotions like pleasure or frustration and aggressiveness so we can say it is “emotional”. But there are, nevertheless, differences between those two: as I already said, the right hemisphere especially handles new things, unfamiliar or risky, and handles as well spatiality, while the left hemisphere deals with familiar things, habits and details. In terms of language the common belief is that it is situated in the left hemisphere. But the reality is more complex. Both hemispheres handle the language but the left one deals with the meaning of the words and sentences while the right one interprets the tone of voice and intonation.

The stress and relaxation hemisphere. There is still a bit of truth. People differ in terms of how “active” an hemisphere is in a relaxation state, when we have nothing to do. At some people the left hemisphere is more “active”, while at others the right hemisphere “surpasses” the left one. Because of this, the first ones are more relaxed and predisposed to positive emotions while others are more tense, stressed out and excessively cautious. As for the differences between men and women there are two myths: the first one states that the women, being more talkative, have the left hemisphere more active, another one states that the women are more emotional, so the right hemisphere is more active. The truth is there aren’t any activation differences between men and women but interconnectivity differences. To be more specific, women have the two hemispheres better connected than the men. And they have a maximum connectivity “in that period of the month”. At men, the two hemispheres are a little bit more independent of each other.

Fortunately, we use just a little bit of our brain! As for how much we are using our brain...this is one of the most popular neuromyths. It was unjustly assigned to Einstein and it represented the “beating horse” of New Age Era back in the 70-80s. The truth is quite the opposite. If we use a difficult mental exercise and ask a six years old child, a 20 years old person and a 70 years old man to solve it, meanwhile watching on a fMRI what is happening in their brains, we can see the following: most mistakes – explicitly – are registered by the child and the old man, and the fewest by the young man. But in terms of brain “activation”... the most active is the brain of the person who mistakes the most. The brain operates under the economy of resources policy – at the beginning of a difficult task it consumes a lot of resources and then, as it learns, it consumes fewer, only in the areas specifically dedicated to that activity. Large activations in the brain are specific to some serious mental disorders like schyzophrenia, depression or panic, as well as – on a normal person- to low performance or feeling of lack of control. Brain practice leads to a normalized resources consumption during difficult or new tasks.