What Are Mirror Neurons and Why Do We Have Them?

What Are Mirror Neurons and Why Do We Have Them?

Mirror neurons activate in our brains when we watch other people do something.

Mirror neurons are nerve cells that get activated when we observe the actions of other people (di Pellegrino et al., 1992). More specifically, they are neurons that would also be activated if we were engaging in that same action ourselves.

There are two kinds of mirror neurons: strictly congruent and broadly congruent ones. Let’s keep talking about cheeseburgers to understand the difference. Suppose you pick up your cheeseburger with your left hand, using your thumb and pointer finger. Some of the mirror neurons that would activate in my brain would be strictly congruent mirror neurons, which are specific to just this action of grasping with thumb and pointer finger. Meanwhile, broadly congruent mirror neurons in my brain would also fire as you picked up the cheeseburger, but these mirror neurons might also activate if you picked up the cheeseburger with all five fingers or used both hands.

The original definition of mirror neurons as needing to relate to actions we observe visually has since been expanded to include other sensory experiences such as using a tool, hearing a sound associated with an action, or even simply observing an object (Bonini et al., 2022). For example, looking at an apple might activate some of the neurons in your brain associated with picking up food and eating it. Or if you’re sitting in my office and hear your colleague open a can of soda, it may trigger mirror neurons associated with holding a can or bottle.

Why Are Mirror Neurons Important?

It seems that mirror neurons are not limited to humans. (In fact, they were discovered in monkeys—more on that in a moment.) The fact that mirror neurons appear to exist across numerous different species, and appear to be present in many different areas of the brain, suggests that they serve some very important function for our survival and well-being (Bonini et al., 2022).

It has been proposed that the function of this is to allow us to understand the experiences and feelings of others in our species (Van Overwalle & Baetens, 2009). By internally having the same experience as another person, we get to both understand how that experience works and learn whether it is a good experience to have or not. This may be one primary reason mirror neurons are important: They help us understand if something is risky or dangerous (Porges, 2007). In other words, mirror neurons may be a factor in observational learning; when we see someone do something that hurts themselves, it often leaves a painful impression on us too. 

“All our sentiments – religious, romantic or any other – are born in the neurons.”
― Abhijit Naskar

What Is the Function of Mirror Neurons?

Let’s look a little deeper at this function of mirror neurons. Scientists think that in watching others perform an action, we try to map it onto our own bodies without actually engaging in the action—that’s where mirror neurons come in (Rizzolatti et al., 2001). If as a child you watched your older sibling touch a hot stove and recoil from it, it was probably better for you to realize that their action was painful through imitating it in your mind rather than trying it out yourself. Simply by seeing your sibling take the action and then leap away in pain, you learned that touching a hot stove—performing the same action—should be associated with a painful response.

This process also prepares us to imitate other people, even in ways that have no clear function (Rizzolatti, 2005). In this way, we may be different from monkeys, in whom mirror neurons were originally discovered. The mirror neurons in monkeys seem to activate when they witness another monkey engage in a goal-directed action such as picking up a piece of fruit to eat it. Humans have mirror neurons that activate in a more complex way, such that we understand not just why somebody is doing something but how they are doing it (Rizzolatti, 2005).

Biologists and social scientists have long known that learning through observation is an essential part of learning for many species. Mirror neurons may help explain how we understand what another person is thinking when they do things (Iacoboni, 2009). They support this learning by converting our sensory experience—what we see and hear others do—into a felt understanding of what it would be like to do those things ourselves. Then we can combine that information with the cues we get about the person’s feelings and thoughts, and, all of a sudden, we are experiencing the other person’s behavior alongside them.

Our mirror neurons are highly adaptive and get tons of input over the years (Cook et al., 2014). Think about how you might automatically squirm or feel uncomfortable when you watch somebody get injured in a movie or eat something disgusting on a reality TV show. Why should you have this reaction? You are physically unharmed, sitting there on your couch. But if you have no reaction to their experience, you might not learn to avoid that same situation yourself—and you might not come to their aid if it were a real-life situation.

In Sum

The existence of mirror neurons in our brains is beyond dispute at this point, but scientists remain cautious about drawing firm conclusions regarding just how important they are for our functioning (Heyes & Catmur, 2022). For the vast majority of us who are not neuroscientists, mirror neurons represent another fascinating component of our incredibly complex and effective brains. How cool is it that we learn so much about the world simply from imagining what another person is doing—from putting our neurons through the same experiences they are having?

References

● Bonini, L., Rotunno, C., Arcuri, E., & Gallese, V. (2022). Mirror neurons 30 years later: implications and applications. Trends in Cognitive Sciences, 26(9), 767–781.

● Cook, R., Bird, G., Catmur, C., Press, C. & Heyes, C. (2014). Mirror neurons: from origin to function. Behavioral and Brain Sciences, 37(2), 177–192.

● di Pellegrino, G., Fadiga, L., Fogassi, L., Gallese, V., & Rizzolatti, G. (1992). Understanding motor events: a neurophysiological study. Experimental Brain Research, 91, 176–180.

● Heyes, C., & Catmur, C. (2022). What happened to mirror neurons? Perspectives on Psychological Science, 17(1), 153–168.

● Iacoboni, M. (2009). Imitation, empathy, and mirror neurons. Annual Review of Psychology, 60, 653–670.

● Porges, S. W. (2007). The polyvagal perspective. Biological Psychology, 74(2), 116–143.

● Rizzolatti, G. (2005). The mirror neuron system and its function in humans. Anatomy and Embryology, 210(5–6), 419–421.

● Rizzolatti, G., Fogassi, L., & Gallese, V. (2001). Neurophysiological mechanisms underlying the understanding and imitation of action. Nature Reviews Neuroscience, 2(9), 661–670.

● Van Overwalle, F., & Baetens, K. (2009). Understanding others’ actions and goals by mirror and mentalizing systems: a meta-analysis. NeuroImage, 48(3), 564–584