The pinnacle of courage

What exactly happens in the brain when we act courageously?

Spiders, injections, exams - we all have fears. And yet, most of us, if not all of us, are sometimes able to act courageously, whether in everyday life or in emergency situations. Courage is the overcoming of fear, that is, the choice to act contrary to what the fears try to dictate to us. But what exactly happens in the brain when we act bravely?

It is difficult to study the brain mechanisms of courage, not only because acts of courage are usually one-time and unpredictable, but also because imaging brain activity while performing the behavior requires the subject to lie motionless inside the imaging device. Prof. Yadin Dodai and research student Uri Neely, from the Department of Neurobiology at the Weizmann Institute of Science, together with their colleagues Hagar Goldberg from the Weizmann Institute and Prof. Avraham Weizmann from the Gaha Medical Center, found a way to do this, and as a result were able to identify for the first time the brain area responsible for courage. To this end, they designed an experiment that allows them to examine what is going on in the minds of people who are afraid of snakes while they are trying to overcome their fear of a live snake, and thus study the neural mechanisms of courage in a controlled manner. The experiment was done with the assistance of Dr. Edna Furman-Haran, Nahum Stern and Fani Atar from the Center for Human Brain Imaging at the Institute.

The volunteers who participated in the experiment were divided into two groups, according to a questionnaire that rated their degree of fear: the fearful group, in which snakes arouse great fear, and the "fearless" group who are not afraid of snakes.

The volunteers from both groups entered an fMRI scanner. Behind their heads was installed a conveyor belt with a large snake attached to the cart with a special collar. The volunteers could control the movement of the cart - to move away from or close to their head - using a button. The task assigned to them was to bring the cart, with the moving snake on it, to their backs - as close as they dared. In addition to the fMRI scan, the scientists also tested the physiological response of the volunteers to fear, by measuring the conductivity of the skin - which is a measure of sweating, and therefore the learning of physical arousal - in a similar way to how a "truth machine" works.

The findings of the study, recently published in the journal Neuron, show that while the fearful overcame their fear and brought the snake closer to them, a specific area in the front of their brain was activated. The activity in the area was stronger as the level of fear of the volunteers was higher. This mental activity did not take place in the minds of the fearless, whose proximity to the snake did not require them to behave with special courage. Regarding this area of ​​the brain, it was previously found to be related, among other things, to depression. Increased activity of the courage center was accompanied by a decrease in sweating.

The researchers also found that the neural activity in another brain structure in the middle of the brain, known to mediate fear responses - the "tonsillar body", or the amygdala - was the opposite of that which occurred in the courage center: when the fearful overcame fear, a decrease in amygdala activity was seen, while when they succumbed to fear, it increased the activity Following the findings, the researchers proposed that there is a brain mechanism that involves a mutual reaction between nerve networks in the brain, which allows a person to overcome fear, with a momentary decision, and perform a courageous activity.

Uri Neely: "Our findings show how the activity of the 'Courage Center' suppresses certain aspects of the fear response mediated by the activity of the amygdala, thus enabling the courageous action." Prof. Dudai: "These findings shed light on the brain activity that underlies essential and noble human behavior. In addition, they will be able to lead to a better understanding of what happens in the brain when fear acquires excessive control over it - as, for example, in cases of various anxiety disorders. Such an understanding can lead, in the future, to the development of methods that will affect the activity in these areas of the brain, in order to treat anxiety disorders."