Short answer
The idea that we could somehow increase our brain potential is very attractive. But this is a fantasy. Even defining how one’s brain potential is reflected on the brain is hard. For example, there is no single area of the brain that is not used, as if waiting to be ‘unlocked’. Furthermore, the level of brain activity is not an indicator of brain potential: low levels of activity could cause a coma, too high levels activity could cause a seizure. So, it is not true that we only use a small fraction of our brains.
Longer answer
We all have heard about the idea that ‘we only use a small percentage of our brain’. This is a ‘common knowledge’ often present in pop culture, seducing us with the idea that we can become smarter by unlocking the rest of our brain (usually in a fast and easy way!). But is there any truth in this affirmation? To answer this question, we first need to understand what it means to ‘use only a percentage of the brain’. Is it related to a more abstract concept of brain potential? Or does it refer to the number of brain cells that are active at the same time? Or even the presence of ‘silent regions’ that are inactive in the brain? Let’s try to navigate through each of those possibilities in light of what neuroscience can tell us.
First, most of what we know about ‘how the brain processes information’ comes from the study of neurons, how they interact with each other and thereby process information in the brain. Each of the approximately 20 billion neurons in our brains are connected to ~10.000 other neurons, making it an extremely complex system. And because of that, it is hard to find a way to improve the functionality of the brain. Is having a more connected brain better? Or maybe having less of one specific neuron type (yes, neurons come in different shapes, sizes etc.)? The answer is, it depends! In some brain regions, richer connections would be beneficial, while in other brain areas, it would be detrimental. If something affects the brain negatively (such as the degradation of brain connections), it does not mean that the opposite will have a positive effect.
A second way to think of the ‘10% brain’ is to consider the number of cells that are active. For example, one could say that we don’t use our full potential because not every neuron is active at the same time. That last part is true, but that is actually a good thing. The brain has a delicate balance between activation and inactivation of cells that prevents all the neurons from firing at the same time. For some people, when this balance is disturbed, their brain enters in a state of high synchrony, with multiple cells active at the same time. And this causes an epileptic seizure; not something you would want.
A last alternative to the idea of an ‘inefficient brain’ could be the existence of inactive brain regions. However, from an evolutionary perspective, it would not make sense to keep cells or whole brain regions that serve no purpose in our brain, since the brain consumes the most of our energy. In fact, imaging techniques (such as the MRI) show the activation of various brain regions even during simple tasks such as eating. There does not seem to be room for the existence of a ‘secret region’ waiting to be ‘unlocked’.
While the possibility of ‘unlocking our full brain potential’ sounds very attractive, there is no concrete evidence that we don’t already use our full potential. Maybe future researchers will discover new evidence that changes this fact. But, for now, there is no shortcut to learning. And, although we can still enjoy a good science fiction, we have to watch out for anyone trying to sell us this ‘brain myth’ in a scientific disguise.
Useful sources:
50 Great Myths of Popular Psychology: Shattering Widespread Misconceptions about Human Behaviour (2010). Scott O. Lilienfeld, Steven Jay Lynn, John Ruscio, and Barry L. Beyerstein
Movie: Lucy -> is about this topic, but not scientifically accurate 🙂