Do we only use 10% of our brain capacity?

01/12/2023 at 05:12:16

The human brain is the most complex organ in the entire organism. Formed by neurons and glial cells, the brain is largely responsible for controlling motor activities, thinking, consciousness, cognition, memory, learning and for controlling vital functions of the human body.

Due to its complexity, many studies have not yet been fully elucidated about the anatomy and physiology of the brain. Therefore, many doubts and myths arise about its functioning and cytoarchitecture. Therefore, it is worth noting that many scientific researches were carried out with the aim of demystifying the myths and answering questions with a scientific basis, following the rigor of scientific methodology.

In this sense, the human brain was believed to be composed of approximately 100 billion neurons and 1 trillion glial cells, as presented in 1979 by Canadian neurobiologist Nobel Prize in Medicine, David Habel. The neuron is described in the literature as the cell responsible for processing information and the glial cells as support cells. Following the ratio of 10% neurons to 90% glial cells implies that only a part of the entire human brain is used.

We can also evidence the myth's roots when we historically evaluate neuroscientific texts. Psychologist William James, who wrote in his 1907 text, The Energies of Men, that "we are using only a small part of our possible mental and physical resources."

However, it is now known from functional magnetic resonance (fMRI) experiments that the entire brain is active, even during sleep.

According to neuroscientist professor Suzana Herculano, in her review published in the European Journal of Neuroscience “at least four basic concepts of neuroscience need to be rethought”.

Among them, the total number of neurons that make up the human brain. To this end, Suzana and neuroscientist Robert Lent, in studies conducted at the Laboratory of Neuroplasticity of Biomedical Sciences (ICB) at UFRJ, developed a cell fractionator and stereology techniques to calculate with greater precision the number of neurons and glial cells present in the various regions of the human brain. When performing the procedure, researchers use chemical compounds to dissolve cell membranes and count only the nuclei. To differentiate between neurons and glial cells, scientists used markers.

Herculano and Lent published without their studies that the human brain has approximately 86 billion neurons and 85 billion glial cells, with 16 billion neurons present in the brain, 69 bi in the cerebellum and 0.7 in the brainstem.

In this sense, research using fMRI and positron emission tomography (PET) shows that simple activities such as shaking hands, watching a movie or spelling words require more than 10% of brain activity. Therefore, it is worth noting that we use 100% of our brain every day. The use of only 10% of the brain is a scientific myth.

References:

ZORZETTO, R. Números em revisão: Recontagem de neurônios põe em xeque ideias da neurociência. Revista Fapesp, 2012. Disponível em :< https://revistapesquisa.fapesp.br/2012/02/23/n%C3%BAmeros-em-revis%C3%A3o/>. Acesso em: 14.01.2020

LENT, R. et al. How many neurons do you have? Some dogmas of quantitative neuroscience under revision. European Journal of Neuroscience. v 35. n. 1. jan. 2012.

HERCULANO-HOUZEL, S.; LENT, R. Isotropic fractionator: a simple, rapid method for the quantification of total cell and neurons in the brain. Journal of Neuroscience. v. 25. n. 10. p. 2.518-21. 9 mar. 2005.

HERCULANO-HOUZEL, S. Você usa apenas 10% do seu cérebro? Folha de São Paulo, 2006. Disponível em: < https://www1.folha.uol.com.br/fsp/equilibrio/eq0806200608.htm>. Acesso em: 14.01.2020

HAMMOND, C. Do we use 10% of our brains? BBC, 2012. Disponível em: < https://www.bbc.com/future/article/20121112-do-we-only-use-10-of-our-brains > Acesso em: 14.01.2020

LEWIS, J. G. "Lucy" is Wrong; We Use Way More Than 10% of Our Brains.Scitable, 2014.

Disponível em: < https://www.nature.com/scitable/blog/mind-read/lucy_is_wrong_we_use/ > Acesso em: 14.01.2020