Not so long ago a breakthrough in neuroscience took place. It came in the form of neuroplasticity. The concept refers to the ability of the brain to change during our entire life. It puts aside the old theory that the brain fully forms early in our development and then remains static for the rest of life.

Now we know, and have proven, that everything we do alters our brain not only on the molecular and cellular level, but also leads to the rewiring of brain and sometimes significant morphological changes inside the organ. When we learn, walk around a new place, meet somebody new or achieve new experience, our brain and its connections change.

Some brain areas become larger, some others shrink in size, some become more active, while others get inactivated. The process is known to be mediated by the production and release of a protein called NGF (nerve growth factor) which creates more connections between neurons.

An interesting aspect of this new view of brain functioning is the notion that our positive or negative attitude towards life can physically shape and change our brains. Experimental evidences for that come from the Human Connectome Project.

The Human Connectome Project aims to build a “network map” of the brain and create a detailed database of the anatomical and functional connectivity in the brain and, by doing so, advance our understanding of brain’s normal and pathological functioning.

Attitude in the brain

In a recent article published in the journal Nature Neuroscience, researchers from Oxford University analyzed the fMRI data from 461 project participants. Specifically, they mapped the links between 200 regions of the brain. Each participant also filled a questionnaire that helped to establish his or her basic behavioral traits and attitudes.

Among other things, the scientists discovered that people with behavioral traits normally viewed as negative or positive had markedly different connectional and functional brain characteristics. These differences in brain connections prove that our basic attitude is indeed reflected in our brain structure. It is tempting to speculate that mechanisms of neuroplasticity may play a role in changing our attitude throughout life and thus have positive or negative effects on our health and wellbeing.

A number of other interesting experiments has demonstrated the link between our attitude and behavior and the changes in various regions of the brain.

Role of the amygdala

In a 2013 study, researchers at Stanford University School of Medicine discovered that amygdala size plays a crucial role in anxiety and negativity.

Researchers measured amygdala size in 76 participants (children aged between 7 and 9 years old) and came to the conclusion that basolateral amygdala size and strength of connection with the neocortex in children can predict the degree of anxiety. Previous experiment on laboratory animals demonstrated that when they were exposed to a stressful environment for a long time, their amygdala grew additional synapses which led to chronic stress. These findings prove once again that chronic stress and PTSD are associated with amygdala size and connection strength.

Role of the orbitofrontal cortex

Another study demonstrated a link between the size of the orbitofrontal cortex and optimism. The orbitofrontal cortex plays an extremely important role in emotional and behavioral regulation.

Researchers asked 61 young adults to complete a set of tests that provided information about their optimism and anxiety levels. After this, researchers studied the size and volume of gray matter in the orbitofrontal cortexes of participants using fMRI. The results showed that the thicker the gray matter of the orbitofrontal cortex the higher optimism level and lower anxiety level the participants demonstrated.

A Japanese study performed in the wake of devastating earthquake and tsunami of 2011 convinsingly demonstrated the link between post-traumatic stress disorder and volume of orbitofrontal gray matter.

Researchers performed repeat fMRI scans on people for whom they had the fMRI data preceding the earthquake. The results showed that orbitofrontal cortex gray matter volume was decreased due to atrophy in a number of participants. The ones who lost the most orbitofrontal cortex grey matter volume were most likely to be diagnosed with PTSD.

In a follow-up study in 2013, researchers found that those individuals who were diagnosed with PTSD had developed microstructural damage in orbitofrontal white matter. This proved that the size and connectivity of the orbitofrontal cortex plays an extremely crucial role in reducing the anxiety and maintaining optimism. Other studies have also demonstrated the link between chronic stress and long-term structural changes in grey matter in a wide range of brain regions.

On the other hand, another recent study found the brain changes associated with positive emotions. A paper published in the Journal of Neuroscience shows that higher activity of the ventral striatum is linked to the release of higher levels of cortisol, the stress relieving hormone. Release of cortisol results in reducing stress and keeps an individual in a positive state of mind. The result is rather interesting, taking into account that for a long time it was believed that ventral striatum’s only function was the regulation of the reward mechanisms.

The recent discoveries mentioned in this article change our views rather substantially. We always assumed that individual variations in various brain structures influence our behavior. But it appears now that the opposite is also true: our behavior and lifestyle choices can influence and change the structures inside our brain.

References

Dolcos S, Hu Y, Iordan AD, Moore M, & Dolcos F (2015). Optimism and the brain: trait optimism mediates the protective role of the orbitofrontal cortex gray matter volume against anxiety. Social cognitive and affective neuroscience PMID: 26371336

Heller, A., Fox, A., Wing, E., McQuisition, K., Vack, N., & Davidson, R. (2015). The Neurodynamics of Affect in the Laboratory Predicts Persistence of Real-World Emotional Responses Journal of Neuroscience, 35 (29), 10503-10509 DOI: 10.1523/JNEUROSCI.0569-15.2015

Sekiguchi, A., Sugiura, M., Taki, Y., Kotozaki, Y., Nouchi, R., Takeuchi, H., Araki, T., Hanawa, S., Nakagawa, S., Miyauchi, C., Sakuma, A., & Kawashima, R. (2012). Brain structural changes as vulnerability factors and acquired signs of post-earthquake stress Molecular Psychiatry, 18 (5), 618-623 DOI: 10.1038/mp.2012.51

Smith, S., Nichols, T., Vidaurre, D., Winkler, A., Behrens, T., Glasser, M., Ugurbil, K., Barch, D., Van Essen, D., & Miller, K. (2015). A positive-negative mode of population covariation links brain connectivity, demographics and behavior Nature Neuroscience DOI: 10.1038/nn.4125

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