For Elmer, the protagonist of the Spanish series The Gardener , killing is as easy as planting petunias, since a childhood accident deprived him of feelings. Is it possible that physical changes in the brain activate or deactivate our ability to feel? The answer is yes: a brain injury not only affects speech or the mobility of a certain part of the body, but can also affect our ability to feel emotions.

Beyond the fictional story of Elmer, science has reported numerous cases of people with emotional impairment. It is these true stories that have allowed us to anatomically and physiologically locate the brain’s emotional control centers.

When reality surpasses fiction

The most famous case is that of Phineas Gage , a railroad foreman who, after an accident in 1848 in which an iron bar pierced his skull, experienced a radical change in personality . More than a century later, Antonio Damasio’s patient, Elliot , underwent a similar change after surgery to remove a brain tumor. Like Phineas, he retained his cognitive and language abilities, but his life fell apart as he became unable to make even mundane decisions wisely.

After observing similar experiences in different people, Dr. Damasio concluded that certain brain lesions (ventromedian and dorsolateral prefrontal cortex, right somatosensory cortex, anterior cingulate cortex, and amygdala) severely compromise the ability to feel emotions and thus the ability to make plans, anticipate social consequences, and, ultimately, make good decisions.

According to Damasio’s patients, the hardest thing to believe about The Gardener series is that Elmer is capable of making and following a plan, since, as has been shown, the absence of emotions greatly reduces executive functions.

Early stage injuries

When similar brain injuries occur at birth or in youth, similarly anomalous behavior occurs. Psychologists, psychiatrists, and neurosurgeons of the 1940s agreed when describing patients deprived of a theory of their own mind and the minds of those with whom they interact. These individuals’ behaviors were “stereotypical, lacking originality, creativity, or initiative; rigid and persevering in their approach to life, unable to organize their future activities or hold down a job; they tended to boast and display a favorable opinion of themselves.”

Fortunately, none of them had a mother like Elmer ‘s , who took advantage of his condition to turn him into a hitman.

Lobotomies and loss of emotions

If there is still any doubt about the role of the prefrontal cortex in emotions and of these in reasoning, we only have to review the consequences of the transorbital lobotomies that became fashionable in the mid-20th century to treat extreme psychiatric conditions.

Although they relieved certain symptoms in some cases, they often left patients with severe behavioral changes related to the loss of their emotional abilities, as happened to Rosemary Kennedy . Of course, these practices ceased.

Preserving emotions, the challenge of neurosurgery

In reality, nothing is ever that simple when it comes to the mind. Cellular plasticity makes the brain a dynamic and flexible whole, so that emotions, like language, thought, or movement, are the result of the constant and dynamic interaction of multiple neural networks.

Neurosurgeon Jesús Martín-Fernández has set out to preserve his patients’ emotions by preserving not only the important “cities” of their brains, but also the “highways” that connect them (such as the default mode network, the salience network, or the inferior fronto-occipital follicle).

Traditionally, neurosurgery in awake patients has focused on preserving language and mobility. Without diminishing these achievements, the removal of brain tissue has often had dramatic effects on patients’ emotional capacities, as the tissue was removed along with the tumor, as it could not be detected.

Martín-Fernández operates on his patients with the help of a neuropsychologist who assesses emotions and feelings live, with the goal of not damaging the connections that cause them while removing the tumor. In this way, they manage not only to preserve the person’s complete humanity (language, movement, and emotion) but also to increase our understanding of the emotional brain.

Emotions and feelings: a dynamic duo

At this point, it may be worth clarifying that emotion and feeling, although used interchangeably, are not the same thing.

Emotions are automatic and measurable physiological responses that occur in our bodies in response to a stimulus (an increase in heart rate, a facial expression, sweating). And feelings are the conscious and subjective experience of those emotions.

That is, feeling is the way the mind interprets and makes sense of these bodily changes. Joy, sadness, fear, anger, disgust, and surprise are basic emotions that, when interpreted, give rise to a wide range of feelings such as happiness, loneliness, anxiety, frustration, rejection, or enthusiasm.

Areas of the brain to put yourself in someone else’s shoes

Feeling emotions is as genuinely human as embracing the emotions of others. The insula is a region known as the brain’s mirror and is responsible for our feeling of rejection when we see someone pull a face of disgust after tasting a glass of spoiled milk. Injury to this region nullifies this capacity in any person, to the point that we might see someone vomiting and interpret it as them having a great time.

In pregnant women , changes occur in the amygdala that make them more sensitive to perceiving and responding to facial expressions of threat or well-being.

The amygdala is so important in the perception and interpretation of visual stimuli that a person with visual blindness due to damage to the visual cortex (but not the retina) is able to reproduce facial expressions shown to them even though they cannot see them. This is only possible if the connections between the eyes and the amygdala are maintained.

What does the body have to do with all this?

The body establishes a constant, two-way relationship with the brain that also affects emotions . Breathing, posture, gut microbiota, and heart rate all seem to affect our emotional perception and, therefore, how we evaluate situations.

There is solid evidence, therefore, that emotions, and with them feelings, are generated thanks to the activity and connections established between different areas of the brain. Damage to the brain areas involved could leave a person like Elmer, just as it happened to Phineas Gage or Rosmaryn Kennedy, without the ability to love, be afraid, or feel sad. What that person would become will depend fundamentally on their environment and the psychological care they receive.

Author Bio: Noelia Valle is Professor of Physiology, Creator of Noe’s Blackboard at Francisco de Vitoria University