Our brain can be perhaps categorized as one of the most important organs in our body. Yet, it is, unfortunately, an organ that we know very little about despite the vast amount of research that has been conducted on it. Since the time of the ancient Greeks, people have talked of mind and body, and reason and emotion as dualities, different, without any dependencies. It was the French philosopher Rene Descartes, after whom the Cartesian Dualism was named.

The concept of mind-body and reason-emotion dualism cannot stand up to scientific reasoning today. This is because unlike 19th-century belief, mind, body, reason, and emotion are inextricably linked. Descartes’ Error (1995) by Antonio Damasio attempts at helping us view and understand the brain in a different light, and how these are all intimately linked.

Scientists have been studying the varied consequences of brain damage in order to understand how it works, and mapping the exact functions of the brain’s different parts, much like how an engineer dismantles a machine part by part to understand how each part functions.

Experimental neuropsychologists and neuroscientists have delved deeper into brain studies by examining different case studies, and have made remarkable discoveries, enabling us to know a little more about the vast abyss that our brain is.

Descartes’ Error by Antonio Damasio
Descartes’ Error by Antonio Damasio

The Case Of Phineas Gage 

Phineas Gage was a railroad construction foreman in the 19th century, working in Rutland & Burlington Railroad Company in Vermont. Known as a diligent and dependable, and efficient employee, he had one of the most demanding, delicate, and dangerous jobs – to set-up demolition explosive charges. 

In 1948, Gage met with an unfortunate accident where a sudden explosion sent an iron rod through his skull. The slender rod pierced his left cheek and passed through from the top of his head, landing a few feet away. Shockingly, he survived the accident, as well as was able to sit up a few minutes later and talk. Gage lived for more than a decade after the accident.

After recovery, while gage showed normal brain functioning in areas of intelligence, cognition, perception, memory, and language, according to his friends, he was no longer the same person he was before. He lost respect for social conventions, started swearing, lying, ignoring sound advice, and became impulsive.

He never seemed to be able to stick to any goals or follow a plan of action. He would come up with a number of schemes, only to drop them off mid-way. Sadly, Gage lost his job and finally worked as a sideshow in a circus.

Though scientists did not have Gage’s brain to study, his skull was preserved in the Harvard Medical School. Advanced simulation technology has enabled doctors and scientists to replicate the trajectory of the rod in simulation. They found out that in probability, the ventromedial prefrontal cortex (VPC) of Gage’s brain was damaged in the accident.  

Elliot: A Real-Life Study

Elliot (a pseudonym given by the author), another person who suffered damage to the VPC, though due to a brain tumor, like Gage, was a well-to-do, happy businessman, and a father. His symptoms were similar to that of Gage’s – normal to above average functioning of language, abstract moral reasoning, facial recognition, visual perception, memory, and general intelligence, etc., yet displaying questionable practical reasoning skills.

He struggled to prioritize his tasks in a day, couldn’t make sound business decisions, and spent his time doing work that was absolutely irrelevant. He, like Gage, lost his job, got caught in ill-fated and ill-advised money-making schemes, and ended up unemployed, divorced, and bankrupt. 

There’s More To Practical Reasoning Than Just VPC 

Both these cases, along with 12 other cases that were studied by the author and the author’s colleagues confirm the fact that damage to the VPC thwarts practical reasoning abilities. However, considering that there is a difference between correlation and causation, one cannot say that disability in practical reasoning is caused by damage to VPC and the VPC alone.

While functions are assigned to different parts of the brain, different parts do not function in isolation. Therefore it is possible that damage to two different parts of the brain can result in similar symptoms as that of damage to the VPC; for example, any damage to the anterior cingulate and the amygdala (parts of the limbic system responsible for processing emotion), or damage to the somatosensory cortex responsible for the visceral states such as sensations of the gut, heart, skin, lungs, etc. and functions such as touch, temperature, pain, joint position.

Therefore to put in an equation –  

Practical reasoning = the VPC + the limbic system + the somatosensory cortex.

However, it’s not as simple as arithmetic. That’s because scientists do not know how these big 3 functions together to bring about practical reasoning. 

Additionally, how do physical sensations and emotions add into the equation of practical reasoning? 

The author found the answer in an “Aha!” moment during his hypothesis and research on Elliot. He noticed something funny in the manner in which Elliot narrated his life during many of their sessions. Despite his life story being a sad one, filled to the brim with divorce, financial problems, and losing his job, he never displayed any emotions such as sadness, grief, regret, at all. He didn’t show any annoyance either at the endless questions asked either. The author found out that Elliot responded to everyone and everything flatly, without any display of emotions. While he did have bouts of anger, he would go back to being neutral in an instant.

To study this further, Elliot was subjected to another experiment where he was shown strong emotional pictures, like those of burning houses, injuries. That is when Elliot himself flatly declared that he did not feel any emotions any longer. It was an observation that was seen even in the 12 other patients with damage to the VPC.

 Therefore, in addition to deficits in practical reasoning, they also found flat emotions a symptom in VPC damage.

How Emotions Work Vis A Vis The Big Three

With this new information, the author found a correlation between emotions and practical reasoning. It seemed counterintuitive, as, with emotions out of the way, practical reasoning should have thrived.  However, emotions have a lot more value than we think.

Emotions can be divided into  – 

  • Body State, and 
  • Emotional Body State

The Body State is the change that a person has inside their body, for example, the joints, internal organs, muscles, etc.  This information is passed on from the brain to the organs and back via electrical and chemical signals.

The Emotional Body State, on the other hand, is the sensation that we feel in our body when we experience feelings, for example, relaxing muscles, flushed face while feeling happy and blanching, sweating, and nausea when scared.

Additionally, one can also experience mental images of something that could trigger the emotional body state. These perceptions are representative of anything, such as the sound of a friend’s familiar voice, the memory of the taste of something you ate with the friend, etc., that can trigger an emotional body state.

When we combine these mental images, the body state, and the emotional body state, we get an emotion. These feelings – positive or negative – are the brain’s way of understanding if something’s bad or good. We call these bad or good emotions.

In context to Elliot’s life after the tumor and the VPC damage, his emotions were diminished. However, he still experienced emotions such as anger, sadness, fear, happiness, and disgust in flashes, because these are primary emotions that are hardwired into humans from birth.  

To illustrate let us see how emotional response and practical reasoning take place in situations of fear, and how the big 3 – VPC, Somatosensory cortex, and the limbic system work in tandem.

A person suddenly sees a slithering snake ahead of him. His brain relays the information of the ‘slithering motion’ to the limbic system, which then registers it as danger. It signals to fire the fear response via a series of biological and neurological changes that shift the emotional body state to fear, and the person experiences cold sweat, shallow breathing, and heart-pounding.

Next, based on these body states, the somatosensory cortex analyses the situation as dangerous, and signals the body to experience the fear and the person feels scared. This triggers action and the person runs away.

In this situation, we can see that the VPC isn’t anywhere in the picture yet. It is the reason why people like Elliot can still experience primary emotions. Secondary emotions, being more complicated, are a different matter. 

Our emotions are much more useful and valuable than we think
Our emotions are much more useful and valuable than we think

The More Complicated Secondary Emotions

Secondary emotions are developed over time and experiences. These are dependant on the VPC. To understand how we take the same example as above.

The person sees the snake but is a herpetologist. The snake is a harmless and rare species that delights the person. The delight is a secondary emotion.

We already know that emotion is a mixture of the body state and the emotional body state, and the mental images that are triggered by these two states. To cite the example above, the images of the snake, the perception of the sound of the slithering, etc. are at play, possibly triggered by previous experiences with snakes, or by reading about them in a book. 

Our experiences throughout our lives get collected in our brains and thus we are able to make associations with the millions of things we see and feel daily. For example, a memory of a favorite teacher teaching a person about snakes started the association of snakes with a feeling of happiness. Next, a pet store visit with his dad in the past would have made the association stronger. Finally, the experiences as a herpetologist might have been the full blast that made the person so delighted on seeing the snake.

The somatosensory cortex keeps us aware of the emotional body state whereas the limbic system creates that body state. However, it is the VPC in the prefrontal cortex that ties the two with experiences of secondary emotions.

The Final Clue To Practical Reasoning

The big three – somatosensory cortex, the limbic system, and the VPC – come together to make humans experience their secondary emotions in full glory. Yet, the question that still remains is how is practical reasoning affected by secondary emotions?

In Elliot’s case, during one interview, the author asked Elliot to choose between two likely dates, a few days apart, for their next appointment. Elliot took out his planner and started to enumerate all the possible pros and cons of the two dates. The author did not stop Elliot. He wanted to see how far could Elliot go. After about half an hour, and after considering factors right from other scheduled appointments to the possible weather on those days, the author proposed one of the two. At this, Elliot simply replied, “Fine.” And then left.

The author noted that decision was not important to Elliot at all. It was just that he was unable to make up his mind. While Elliot was able to think about the choices given to him, he was unable to make the choice, which was all about practical reasoning. 

If there is a very important consideration to make when given choices, half an hour of thinking seems considerable, however, in trivial situations, it seems like a complete waste of time. Which is exactly what Elliot was unable to get.

This mystery, of how practical reasoning is affected by secondary emotions, was called the somatic marker hypothesis. The somatic markers are special types of secondary emotions that help in decision-making. Essentially, the secondary emotions – positive or negative – that one feels while trying to arrive at a conclusion help in steering the decision towards either choice.

When the secondary emotions are negative, we have a ‘gut feeling’ making it easier to take the other choice. However in Elliot’s case, because the somatic markers were missing, he got lost in the possibilities he had to choose from, simply unable to decide because he couldn’t ascertain the positivity or negativity of his secondary emotions.


Emotions play an essential role in one’s ability for practical reasoning. thus people are able to make decisions by weighing choices and reasoning on options. Practical reasoning depends on the ability of the brain to read and assess the emotional body state. Therefore, the brain and the body, and emotion and reason all depend on each other to help us make decisions.