Until a few years ago, research on our emotions used to focus on those that are negative, such as anxiety, sadness and phobias. Today several groups of scientists also study positive emotions, as well as the changes that they cause in the brain.
Emotions are experienced in a very personal way that we are generally not aware of, but which manifests itself in facial expression, body posture and in specific mental states. Emotions influence our mood, motivation and even our character and behavior. They also cause physiological reactions because they are related to hormones such as cortisol and norepinephrine, and neurotransmitters such as dopamine and serotonin, which alter appetite, sleep and the ability to concentrate.
Some experts on emotions, such as the Swiss Klaus Scherer, from the University of Geneva, or the late Richard Lazarus, from the University of California at Berkeley, proposed that an important factor in emotions is cognition—that is, the skills and mental processes related to knowledge, such as attention, memory, judgment, reasoning and decision making, which allow us to interpret events consciously or unconsciously and decide how to react. However, other researchers, such as neuroscientist Antonio Damasio, from the University of Southern California, think that the body’s responses are more important than any interpretation of emotions, a point of view that is controversial. His main argument is that changes in the body that accompany emotions can alter the experience. For example, in a recent experiment German and Canadian scientists led by Johannes Michalak of the University of Hildesheim found that just as mood affects our walking position, the way we move also influences our mood. The researchers showed the 39 participants in the experiment a list of positive and negative words. They were then put on treadmills with a meter that moved to one side or the other depending on whether the walking style was “happy” or “depressed.” Participants did not know this about the meter and were asked to walk so that the meter moved to the left or right. At the end of the exercise they had to write the words they remembered from the list. Those who walked “depressed” remembered many more negative words than the others.
There are other models that consider that emotions and cognition are interdependent processes and that each can produce effects on the other. What is increasingly clear is that there is a direct and bidirectional communication between the brain and the rest of the body. For example, fear causes an acceleration in heart rate and breathing, makes us sweat, and keeps our muscles tense.
A correspondence has been identified between emotions and the activity of various parts of the brain. Since the last century, research has pointed out the participation in emotions of a group of structures in the center of the brain that together form the limbic system. Among others are the amygdala, central to the appearance of emotions such as fear and anger, the hypothalamus, which modulates the physiological expression of emotion by producing substances called neurohormones, and the cingulate gyrus and the hippocampus; The latter is a structure very vulnerable to chronic stress and important for the formation of memories. In recent studies on emotions and the brain, it has been found that other structures and brain regions also participate in them.
Dissection of the affections
In the last 40 years, much research has been done to identify brain systems or circuits associated with emotions. It is about knowing, for example, whether each emotion is related to different processing of emotions in the brain with changes in other parts of the body and how this processing interacts with cognition, movement, language and motivation. Recent findings have given rise to a new discipline: the neuroscience of affects or affective neuroscience, which studies the neural bases of emotions and moods; That is, which neurons in the brain are activated when we feel or evoke an emotion.
The same advances have made it possible to observe in real time the parts of the brain that are activated when we feel certain emotions. Dr. Richard Davidson, who directs the Center for Investigating Healthy Minds at the University of Wisconsin-Madison, is, along with the late Paul Ekman, one of the pioneers in exploring the relationship between cognitive and emotional brain. In interview with As you see? He explained that emotion research uses many different techniques. For example, participants in experiments are placed in an fMRI machine (see As you see? No. 181), which records the blood flow of different areas of the brain to measure their activity, and then they are asked to evoke some emotion from photographs or film fragments, or to remember a past experience, and it is observed which areas of the brain become more activated when doing so. Patients with some brain injury are also studied and “the pathologies of brain function in patients with various psychiatric and neuronal disorders that involve abnormalities in emotions,” in the words of Davidson and his collaborators in a 2000 article published in the journal American Psychologist. Until a few years ago, research tended to focus on negative emotions such as anxiety, depression, and phobias. But Dr. Davidson was intrigued by why some people are more positive than others or better able to overcome emotional pain or adverse situations, which is now known as resilience. He found that the difference in level of resilience translates into important differences in brain activity.
In one of their studies on resilience, the results of which were published in the journal NeuroImage in 2012, Davidson and his team discovered that people who used cognitive strategies to modulate their emotions (for example, imagining that a difficult situation represented in a photograph was resolved successfully) had less activity in the amygdala and greater activity in the middle portion of the prefrontal cortex, an area that directs the so-called executive functions of the brain, such as the planning of programs and goals, the ability to anticipate the future and to predict both the results as the consequences of current actions, as well as controlling socially unacceptable impulses.
These results are encouraging, as they suggest that there is a direct relationship between more complex brain regions that are part of our cognitive system, the limbic system, a much older and more primitive region in evolutionary terms. If all our emotional patterns were anchored to the limbic system we would have no escape, we would be slaves to our emotions. Fortunately, emotional circuits are connected to thought and are therefore more accessible to our conscious will.
This does not mean that we can feel what we want; It means that we can modulate emotions. For example, in the aforementioned study, the prefrontal cortex of resilient people sent inhibitory signals to their amygdala that are calming and as a result the negative emotions generated by it decreased. On the contrary, less resilient participants, or those who had depression, presented weaker signals between both regions.
The most interesting thing is that both Davidson and other experts in emotions and the brain have found evidence that we can teach our brain to modulate emotions. The trick could be precisely in the brain’s ability to change: neuroplasticity (see As you see? No. 118).
Capacity for change The main discoveries in neuroscience in the last 15 years are related to different mechanisms of neuroplasticity. Among them the most prominent is the growth of new brain cells or neurons called neurogenesis. “We know that stress can impair neurogenesis, and we know that certain types of activities can promote it,” says Davidson.
It has also been observed that neuronal connection circuits, or synapses, can also be modified. This happens when people become experts at some activity, such as playing the piano, practicing chess, or playing tennis. With the accumulation of hours of practice, a new communication route between neurons in different brain regions is outlined and reinforced in your brain, and this facilitates improvement. It has also been found that the brain maps that represent parts of the body such as hands or legs in the brain are modified after the loss of one of them to cover its lack, as discovered by Vilayanur S. Ramachandran, a specialist in the syndrome known as “phantom limb”, with a patient who was missing an arm and who said his fingers felt missing when someone touched his face. The neuroscientist deduced that an impressive change had been made in this patient’s somatosensory cortex, his brain map. Since his cerebral cortex no longer received stimuli through the lost hand, the region that processes the sensations of the face had been added to that of the hand.
One of the most dramatic evidence of this ability to change is related to modifications in gene expression due to environmental changes, which do not affect the organization of the genome. For example, neuroscientist Eric Nestler discovered that chronic social stress can alter the expression of genes that regulate the hippocampus and nucleus accumbens (a brain region associated with positive emotions), and that these changes affect the physiology and behavior of individuals. individuals, with the addition that they can be inherited to the next generation (see As you see? No. 133).
Davidson notes: “I think our brain exhibits much more plasticity than we thought possible.” And since both the environment and our behavior can cause a reorganization and relocation of certain brain functions, there are now physical therapies that seek to remodel parts of the brain so that they can take over the tasks left behind by another region damaged by a stroke or stroke. There are also cognitive behavioral therapies that allow you to get rid of certain types of phobia.
Brain plasticity allows us to modify our emotions, or at least the way we experience them. “We found that most people can learn to transform their emotions through certain techniques and practices. This does not…