Mirror neurons are brain cells that activate both when we perform an action and when we observe someone else performing it.
First discovered in the early 1990s by Giacomo Rizzolatti and colleagues in macaque monkeys, these neurons were found in the premotor cortex, firing not only when the monkey grasped food but also when it watched a researcher do the same.
Further research showed that monkeys have mirror neurons in both the premotor cortex and the inferior parietal lobule, forming a fronto-parietal mirror system.
By the late 1990s, neuroimaging studies began suggesting that humans have a similar network.
Mirror Neurons in Humans
While we can’t insert electrodes into healthy humans, tools like fMRI, PET, EEG, and TMS have consistently shown that watching someone else perform an action activates brain areas similar to those we use when doing the action ourselves.
This fronto-parietal network includes the inferior frontal gyrus and inferior parietal lobule—regions involved in planning and executing movements.
EEG studies reveal that mu rhythm suppression, a marker of motor activity, occurs during both action and observation. These findings suggest our brains simulate others’ actions internally—a process often outside conscious awareness.
How Mirror Neurons Work
Mirror neurons function by mapping observed actions onto our own motor systems.
If you grasp a cup, a neuron fires. That same neuron may also fire when you watch someone else grasp a cup. This internal simulation allows for intuitive understanding without deliberate reasoning.
In monkeys, mirror neurons were found in areas integrating sensory input with motor planning (e.g., ventral premotor cortex and inferior parietal lobule).
Humans show mirror-like activity in analogous regions: Broca’s area, the ventral premotor cortex (in the frontal lobes), and the inferior parietal cortex—suggesting a shared simulation system.
Even somatosensory areas show this effect, implying we might subtly “feel” the actions we observe.
Studying Mirror Neurons
Researchers study mirror neuron activity using various neuroimaging techniques:
- Functional Magnetic Resonance Imaging (fMRI) study showed that watching someone grasp an object led to increased signal in the observer’s inferior frontal cortex (a mirror neuron area) – especially when the grasp was shown in a context that revealed the person’s intention (grasping to drink vs. grasping to clean).
- Electroencephalography (EEG) shows suppression of the mu rhythm (an oscillation around 8–13 Hz seen over motor cortex) during both action execution and action observation. This suppression indicates that the motor cortex is active when watching others move, much as it is during one’s own movement.
- Transcranial Magnetic Stimulation (TMS) studies have found that the motor system’s excitability increases when a person watches someone else perform an action, like a finger movement, compared to when they watch static images, implying that the observer’s motor neurons are primed during action observation, consistent with mirror neuron activity.
Together, these methods support the existence of a mirror system in humans, though most evidence is indirect.
Key Functions of Mirror Neurons
Action Understanding
Mirror neurons are thought to help us make sense of other people’s actions. Rather than simply observing movement, we tend to intuitively understand its purpose—like recognizing that someone reaching for a cup is likely trying to drink.
This system allows us to go beyond surface-level observation. By internally mapping observed actions onto our own motor systems, we can infer intentions behind those actions.
This contributes to our ability to quickly and effortlessly grasp what others are doing and why, without needing to analyze each movement in detail.
Imitation and Learning
Mirror neurons also play a role in connecting what we see with what we do. This connection is especially important in imitation and observational learning.
From a young age, humans are natural imitators, learning gestures, skills, and behaviors simply by watching others.
This form of learning is not only practical—such as copying how to use a tool or follow a dance—but also social.
Imitation can build connection and trust, even when it’s unconscious. For instance, people often mirror each other’s posture, gestures, or tone during conversation. This subtle mimicry fosters rapport and helps us navigate social interactions smoothly.
By linking perception and action, the mirror system makes it easier to replicate what we see and to understand how others move and behave.
Empathy and Emotions
Beyond actions, the mirror system may help us resonate with the emotional states of others.
When we see someone expressing pain, joy, or disgust, we might internally experience a faint echo of those feelings ourselves.
This neural resonance supports the idea that part of empathy is automatic and embodied.
Emotional mirroring may explain why we wince when watching someone get hurt or feel uplifted by another person’s laughter.
It reflects a broader principle: the brain areas involved in our own emotional experiences can also activate when we witness those emotions in others.
This mechanism likely plays a key role in emotional contagion—the tendency to “catch” others’ moods—and helps form the basis for intuitive, affective empathy.
Social Cognition
Mirror neurons may also contribute to our understanding of others’ minds—a foundational aspect of social cognition.
This includes the ability to infer others’ thoughts, feelings, and intentions, often referred to as theory of mind.
By simulating others’ experiences internally, the brain may provide us with a kind of embodied understanding that supports more complex social reasoning.
This mirroring also shows up in everyday conversations, where people naturally sync their gestures, facial expressions, or tone of voice—an interactional rhythm that strengthens connection.
These abilities are especially important for developing social bonds and navigating the nuances of human interaction.
Mirror Neurons and Autism
The “broken mirror” theory of autism posits that reduced mirror neuron activity may underlie some social and communicative challenges.
EEG studies have found that autistic children often show reduced mu rhythm suppression when watching others move, indicating less motor system engagement.
fMRI studies have also reported lower activation in mirror areas during imitation tasks.
This may help explain differences with imitation, empathy, and interpreting social cues. For example, if a child doesn’t instinctively mirror a smile, they may not learn to smile back, hindering social development.
However, the theory remains debated. Some studies show typical mirror responses in autistic individuals under certain conditions.
Autism is highly heterogeneous, and mirror neuron function may vary across individuals. Moreover, it’s unclear whether reduced mirror activity is a cause or consequence of social differences.
Alternative explanations suggest that primary motor planning difficulties may underlie both movement and social impairments.
The Scientific Debate
While mirror neurons have generated excitement, some early claims—linking them to everything from empathy to civilization—were overstated.
Critics, like Gregory Hickok, argue that many of these claims lack strong evidence. For instance, monkeys with damaged mirror areas can still understand actions, and humans can comprehend movements or speech they can’t physically perform.
Mirror neurons are also more diverse than often assumed. Some respond to specific actions; others to sounds or pantomimes. Context and perspective matter, and not all neurons behave the same way.
This complexity suggests mirror neurons are part of a broader, dynamic system influenced by attention, motivation, and context.
Human studies often rely on indirect measures like fMRI, which can’t confirm that the same neuron fires during both action and observation.
While the mirror mechanism is well-supported, its exact role in human cognition remains an active area of research.
Why Mirror Neurons Matter
Despite the controversy, mirror neurons have reshaped our understanding of how we connect with others.
They provide a neural link between perception and action—showing how we might “feel into” others’ experiences through internal simulation.
Applications in Therapy and Learning
Mirror neuron principles inform rehabilitation strategies like action observation therapy for stroke patients.
Watching movements can help activate motor pathways and aid recovery.
In education, modeling and demonstration are now backed by neuroscience. Watching others perform tasks activates brain areas involved in doing them, priming the learner’s system for action.
This supports the use of visual learning, mentorship, and guided practice.
Early Development
Mirror neurons highlight how infants learn through social interaction. Simple games, facial imitation, and shared attention shape the mirror system and lay the groundwork for empathy, language, and social skills.
Everyday Connection
From flinching when someone stubs their toe to smiling when a friend laughs, mirror neurons help us navigate the social world.
They allow us to understand others’ actions, resonate with their feelings, and respond in kind—forming the neural basis for human connection.
References
Acharya, S., & Shukla, S. (2012). Mirror neurons: Enigma of the metaphysical modular brain. Journal of Natural Science, Biology, and Medicine, 3(2), 118. https://doi.org/10.4103/0976-9668.101878
Dapretto, M., Davies, M. S., Pfeifer, J. H., Scott, A. A., Sigman, M., Bookheimer, S. Y., & Iacoboni, M. (2006). Understanding emotions in others: Mirror neuron dysfunction in children with autism spectrum disorders. Nature Neuroscience, 9(1), 28-30. https://doi.org/10.1038/nn1611
Kilner, J. M., & Lemon, R. N. (2013). What we know currently about mirror neurons. Current biology, 23(23), R1057-R1062.
Iacoboni, M., Molnar-Szakacs, I., Gallese, V., Buccino, G., Mazziotta, J. C., & Rizzolatti, G. (2005). Grasping the intentions of others with one’s own mirror neuron system. PLoS biology, 3(3), e79.
Oberman, L. M., Hubbard, E. M., McCleery, J. P., Altschuler, E. L., Ramachandran, V. S., & Pineda, J. A. (2005). EEG evidence for mirror neuron dysfunction in autism spectrum disorders. Cognitive Brain Research, 24(2), 190-198. https://doi.org/10.1016/j.cogbrainres.2005.01.014
Rizzolatti, G., & Craighero, L. (2004). The mirror-neuron system. Annu. Rev. Neurosci., 27(1), 169-192.
Rizzolatti, G., Fadiga, L., Gallese, V., & Fogassi, L. (1996). Premotor cortex and the recognition of motor actions. Cognitive brain research, 3(2), 131-141.
