The brain is a complex organ divided into many, many different regions and subregions. While we are far from understanding the brain’s functions completely, we do know that some regions are responsible, or at least primarily responsible, for certain things.
The region responsible for critical thinking is known as the prefrontal cortex, often abbreviated as PFC. Let’s delve into what that means.
A Little Anatomy: Regions of The Brain
The brain is divided into four lobes: The frontal, temporal, parietal, and occipital lobes. It is important to remember that the brain consists of a left and right side, or hemisphere, so there is a left and right temporal lobe, occipital lobe, and so on.
- Frontal lobe: This lobe is located at the front of the brain, hence the name “frontal”. You can imagine it as being just behind your forehead.
- Temporal lobe: This lobe is located on the sides of the brain, behind your ears.
- Parietal lobe: The parietal lobes are found above the temporal lobes and slightly behind them. Imagine them as above your ears and towards the back of your head.
- Occipital lobe: This lobe is located at the back of the head.
Functions of The Brain’s Regions
The big divisions of the brain into lobes contain a lot of different structures, each with their own names. The important one for now is the PFC, which is located in the very anterior (or forward-facing) portion of the frontal lobe. As a whole, the frontal lobe is responsible for higher-order cognition, including critical thinking, responding appropriately in social situations, and so much more.
Critical thinking is a common way of referring to what is formally called executive function in the fields of psychology and neuroscience. So if you were to try to find information about the role of the PFC in critical thinking, you might have an easier time if you searched for the role of the PFC in executive function.
But how do we know the PFC is responsible for critical thinking?
Learning About The Brain’s Functions
There are a few ways scientists can determine which areas of the brain control what functions. One way is to conduct a research study by which participants complete various tasks while undergoing brain imaging. The imaging can show which regions were most active while the participant performed certain tasks.
For example, one region might be much more active than another when performing a memory test, while another might be more active when engaging in reading comprehension. These patterns of activity hint at possible roles in the brain for these activities.
Another way is to conduct similar tests for people who have suffered brain damage. This damage might be from a stroke, brain tumor, trauma, or other injury. It could even be due to prior brain surgery that required removing a certain part of the brain.
If research participants with brain damage contained to a specific area are unable to perform tasks that those with intact brains can perform, then we can reason the said area is important for that task. For example, studies point to the dorsolateral prefrontal cortex as being responsible for general executive functioning. Dorsolateral (dorsal = toward the back, lateral = toward the side) is a directional term meant to describe where the region is located, and such terms are commonly used in science and medicine when describing anatomy.
This also means the PFC is not simply the PFC, but it is further divided into subregions that appear to have specific functions. For example, while the dorsolateral PFC, also abbreviated as the dlPFC, is involved in executive function generally, which includes critical thinking, the ventromedial (ventral = toward the front, medial = toward the middle) PFC, or vmPFC appears to be involved in social and emotional aspects of executive function.
In other words, critical thinking is not really a single activity. It can be about choosing an appropriate response in a social scenario just as much as it can be about taking a math test and using reasoning to determine the best way to solve an equation.
Translational Research
As stated above, a good way to learn more about the brain’s functions is to examine individuals who have brain damage. If the damage leads to impairments, we can speculate the damaged area, or areas, are involved in the impairment.
Of course, this type of research in humans requires seeking out and recruiting people who have suffered such injuries, which can be difficult. One way around this is to conduct translational research.
Translational research is research done on non-humans that are meant to apply to, or translate to, human beings, at least somewhat. Mice and rats are often used for this type of research, but other non-human animals can be and are used as well.
While there are obvious differences in size and complexity between a rat’s brain versus a human’s brain, it is still a worthwhile field of study because we can learn more about the various roles of the brain’s subregions and how they are being destroyed or disabled changes things.
A Summary
So the prefrontal cortex, or PFC, is responsible for critical thinking. The PFC is a portion of the frontal lobe, which is located in the furthest frontal region of the brain (behind your forehead). Critical thinking is often referred to as executive function in academic and scientific communities, so when you see executive function, remember this is a more formal term referring to critical thinking.
There are plenty of research studies on executive functioning that combine cognitive tasks with brain imaging to narrow down which regions are most active during a given task. These studies, especially in people who have suffered damage to their PFC, have shown us that the PFC plays a primary role in critical thinking because when the PFC is damaged, executive functioning diminishes greatly or is absent completely.
Research on both humans and non-human animals has been done, and all point to the importance of the PFC in critical thinking.
References
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4176938/pdf/nihms629074.pdf
https://www.edutopia.org/blog/understanding-how-the-brain-thinks-judy-willis-md#:~:text=The%20Prefrontal%20Cortex%3A%20Home%20to,%2C%20emotional%20responses%2C%20and%20behavior.
https://mayfieldclinic.com/pe-anatbrain.htm
