Mirror Neurons and Autism: A Social Perspective
by Sammy Ahmed
The ability to interpret others’ behavior is crucial to everyday social functioning and enables learning about the world through interaction with other people. As early as 42 hours after birth, the ability to imitate others is evident, allowing imitation to develop as an innate form of learning (Kana, Wadsworth & Travers, 2011). Infants’ ability to imitate adult facial expressions, movements and vocalizations from within hours of birth is regarded by many theorists as the foundation from which more sophisticated forms of communication develop (Nagy & Molnar, 2004). Therefore, early imitation is pivotal to human development, as it provides a sense of connectedness between an infant and its world, and more importantly serves as the platform for future social development and competence. More specifically, early imitation plays a substantial role in the development of motor control, communication, and social abilities (Kana et al., 2011). Early imitation also allows children to become capable not only of mimicking actions but also learning novel actions from others. Previous literature regarding imitation and social cognition emphasizes social aspects of imitative learning; however, most recent research has centered on the neural mechanisms that are responsible for imitation.
The recent shift in the literature from the social factors to the neural substrates responsible for imitation is a result of the recent discovery of mirror neurons. Originally studied in monkeys, mirror neurons are a system of neurons located in the premotor cortex, which is the part of the brain relevant to the planning, selection and execution of actions. These neurons fired, not only when the monkey executed a certain action, but also when the monkey observed a similar action (Rizzolatti & Craighero, 2004). Mirror neurons are thought to be responsible for certain imitative behaviors that allow the understanding of other’s actions by mapping them into motor pathways for similar actions performed by the self (McEwan, 2005). Many studies since the discovery of mirror neurons in monkeys have been devoted to proving that they play the same role in humans as they do in monkeys. Although it is difficult to study this phenomenon in humans, numerous neuropsychological studies have found evidence that mirror neurons do in fact exist in humans (Iacoboni, Woods, Brass, Bekkering, Mazziotta, & Rizzolatti, 1999; Buccino, Lui, Canessa, Patteri, & Lagravinese, 2004). For example, Iacoboni et al. (1999) found that the part of the brain that is activated when making a facial gesture is the same part of the brain that is working when observing others’ facial expressions. He further suggested that when people look at faces, they react according to whether expressions are positive or negative. Therefore, it appears as though by sending signals to emotional systems in the brain, mirror neurons also help facilitate and translate the emotions of others. "The mirror system seems also to be involved in the way that we tap into and harness our abilities and put them to use in the world. People are uncommonly adept at watching and translating what they see. Perhaps that is why sports fans tense with the action of the game, grimace and jump up and down; when you know the game, then your neurons are firing as if you’re playing the game" (Mitrani, 2010, p. 248). It is apparent that mirror neurons play an important role in how humans view and understand the world. Furthermore, if mirror neurons truly operate in this manner, then we may have stumbled upon a psychological breakthrough that traces back to how humans socially developed and flourished.
According to Icoboni et al. (1999), "mirror neurons were likely selected during the evolutionary process because they provide the advantage of understanding the mental states of other people in an effortless and automatic way’’ (p. 132). Thus, it can be assumed that mirror neurons have meaningful implications on the way human socialize and learn through observation at both a conscious and unconscious level. Furthermore, these neural mechanisms may underlie our ability to understand intentions, emotions and behaviors of other people, which render us empathetic and social beings.
While mirror neurons may enable us to understand and mimic other peoples’ behavior at a neurological level, all individuals may not be equally equipped to perform such action. For instance, individuals with Autism Spectrum Disorder (ASD) tend to lack essential action comprehension and imitative skills (Marsh & Hamilton, 2011). According to the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev; DSM-IV-TR; American Psychiatric Association, 2000), individuals with ASD markedly display impaired or abnormal social interaction and communication skills, as well as having difficulties engaging in simple imitation games or imaginative play. Although the onset of these disorders has not been fully discerned, understanding mirror neurons and their normal functions may provide insight about how individuals with ASD may lack certain neurological tools that enable normal social functioning.
One theory that may provide insight into the social difficulties experienced by individuals with ASD is the "Broken Mirror Hypothesis". The "Broken Mirror Hypothesis" claims that individuals with ASD have impairments to their mirror neuron system (Press, Richardson & Bird, 2010) and further suggest that the dysfunction of the mirror neuron system is a primary cause of the poor social skills in individuals with Autism (Marsh & Hamilton, 2011). The Broken Mirror Hypothesis has received widespread attention because numerous studies show the link between mirror neurons and socio-cognitive functions that enable individuals to understand another person’s perspective, emotions, behavior and theory of mind (Rizzolatti & Craighero, 2004).
The increase in the diagnosis of ASD and its relationship to mirror neurons has aroused the interest of scholars across various disciplines. For example, neuroscientists Ramachandran and Oberman (2006) designed an experiment by using electroencephalography (EEG) to test children’s brainwaves while performing and observing actions. For most children, the same brainwaves were detected whether they were performing or observing a specific action. However, for children with ASD, brainwaves were only detected when they were performing an action and not detected when they were observing someone else perform the same action, or even when they were imitating another’s action. This finding supports the "broken mirror hypothesis" and clearly depicts the relationship between mirror neurons and the poor social skills observed in children with ASD (Ramachandran & Oberman, 2006). Since mirror neurons systems are responsible for humans’ ability to understand and mimic other peoples’ behavior, the lack of this skill within individuals with ASD can be attributed to an impaired mirror neuron system. Furthermore, the presence of markedly abnormal social interaction and communication skills in individuals with ASD can be a consequence of their "broken mirrors".
Despite the appealing straightforwardness of the Broken Mirror Hypothesis, empirical studies have provided mixed results and ambivalent evidence supporting the hypothesis. Although many studies clearly display the link between ASD and mirror neurons, there are many skeptics that believe studies examining the Broken Mirror Hypothesis do not make clear whether the low imitative skills displayed by individuals who have ASD are due to specific impairments in the mirror neuron system, or impairments in other neurological systems (Press et al., 2010). Furthermore, some studies actually show that some individuals with ASD have functioning mirror neurons systems (Fan Decety, Yang, Liu, & Yawei, 2010) and believe that there is still much to learn about the "broken mirror hypothesis".
Numerous studies claim to have found the link between mirror neurons and ASD, however, an extensive amount of research needs to be done before making clear-cut claims and bridging the gap in the literature. Despite the controversy surrounding mirror neurons and autism, the findings within the literature offer a solid framework from which researchers can build upon. Furthermore, with the dramatic increase in the diagnosis of autism spectrum disorders, gaining a clearer understanding of the role that mirror neurons play in human learning and sociality is essential and may offer an explanation for the core social and cognitive deficits in individuals with ASD. Firmly establishing the link between mirror neurons and ASD can enhance scientist’s understanding of this disorder and serve as platform in developing treatments and procedures to "fix the broken mirrors."
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Sammy Ahmed is a senior in the Applied Psychology program and part of the newly developed Inside Scoop! peer mentorship program. He is currently conducting an independent study focusing on the "Immigrant Paradox" under Dr. Selcuk Sirin's mentorship. Aside from his interests in acculturation and immigration, he is also interested in medicine. He volunteers at the emergency room at New York Presbyterian and upon graduation plans on pursuing a medical degree, with hopes of conducting research in public health and biomedicine.