Mirror NeuronsIrene Losa Aguado

Elena Domingo CalveteKaitlyn McNabb

Maddison NortonEmily Stevens

Discovery of Mirror Neurons

• Discovered in the 1980s and 1990s

• Discovered by Giuseppe Di Pellegrino, Luciano Fadiga, Leonardo Fogassi, and Vittorio Gallese who worked at the University of Parma in Italy.

What is a Mirror Neuron?

• A neuron that fires when• An animal performs an action• The animal observes the same action performed

by another

• Thus, the neuron “mirrors” the behavior of the other, as though the observer were performing the task.

• Directly observed in primate species

• Birds • Imitative resonance behaviors • Form of mirroring system

Development

• Human infant data using eye-tracking measures suggest that the mirror neuron system develops before 12 months of age. • This system may help human infants

understand other people's actions.

• A critical question concerns how mirror neurons acquire mirror properties.

Development

• It’s unclear how newborn babies are able to mimic the facial gestures of another person.

• One possibility is that the sight of tongue protrusion recruits an innate releasing mechanism in neonates.

Brain Areas Composed of Mirror Neurons

Premotor Cortex

• Location:• Frontal Lobe• Supplementary Motor Cortex

• Active immediately before movement

• Receives information about the target to which the body is directing its movement and information about the body’s current position and posture (Kalat, 2013).

Brain Areas Composed of Mirror Neurons

Supplementary Motor Cortex

• Location:• Frontal Lobe

• Active during preparation of a rapid sequence of movements

Inferior Parietal Lobe

• Location: • Lower part of Postcentral Gyrus

• Perception of emotions in facial stimuli

• Interpretation of sensory information

Brain Areas Composed of Mirror Neurons

Primary Somatosensory Cortex

• Location:• Parietal Lobe• Postcentral Gyrus

• Receives sensations from:• Touch receptors• Muscle-stretch receptors• Joint receptors

Gender Differences

• Yawei Cheng

• Neurophysiological measures: • MEG• Spinal Reflex Excitability • Electroencephalography

• Presence of gender differences: • Female participants exhibit stronger

motor resonance than men participants

Gender Differences

• Emotional social interactions:• Better empathetic ability in females

compared to males • Females have greater ability in emotional

perspective taking than do males in face-to-face interactions.

• Recognizing emotions• Male and female ability is similar

Mirror Neurons in Monkeys• Macaque monkey

• Mirror neurons are found in the inferior frontal gyrus and the inferior parietal lobe.

• They found that some of the neurons they recorded from would respond when the monkey saw a person pick up a piece of food as well as when the monkey picked up the food.

*Infants can imitate a human’s face movements*

Article from New York Times

• Other animals:• Monkeys, apes, elephants, dolphins, and dogs.• Rudimentary mirror neurons

• Humans, with their huge working memory, carry out far more sophisticated imitations.

• Social emotions • Guilt, shame, pride, embarrassment, disgust, and

lust.• Based on a uniquely human mirror neuron system

found in a part of the brain called the insula.

Comparison Between Human and Monkey Mirror Neurons

• Both the human and monkey mirror neuron system mediates the same function of understanding actions completed by others and the intentions behind them.

• Infant monkeys and humans can imitate facial gestures of other’s. • Evidence that mirror neurons develop at an

early stage in both monkeys and humans

• Location of the mirror neurons within the brains of monkeys and humans is slightly different.

Evolution • Premotor Neurons

• Types types of training: •Hebbian Learning• Presynaptic cells are constantly activating postsynaptic cells

• Associative Learning• Association between two stimuli of a behavior and a stimuli

Evolution• Premotor neurons need to be trained

in order to acquire mirror properties.

• However, it is unclear how babies are able to mimic the facial gestures of another person.

• The sight of tongue protrusion recruits an innate releasing mechanism in neonates.

Empathy• Research on mirror neurons and “phantom limbs”

suggests an extraordinary human capacity for empathy.

• Example: (Marsh, 2012)• Insular Cortex: Experience a painful sensation• Anterior Cingulate: Cells respond to pain

(agony)• Fire when observing someone else being

poked by a needle

• Mirror neurons are most likely involved in empathy for pain

Empathy Video

https://www.youtube.com/watch?v=Fl8Tc3qNhCc

Language• fMRI studies found areas homologous to the

monkey mirror neuron system in the inferior frontal cortex, proximal to Broca’s Area.

• Broca’s Area: Region of the brain associated with language.

• Suggestion that human language evolved from a gesture performance/understanding system implemented in mirror neurons.

Language• Mirror neurons have the potential to provide a

mechanism for:• Action-understanding• Imitation-learning• Simulation of other people’s behavior

• New word pronunciation in children is linked to mirror neurons

• Speech repetition occurs automatically, fast, and separately in the brain to speech perception.

Language

• Brain activity of two participants was measured using fMRI while they were gesturing words to each other.

• Analysis of data using the Granger Causality

• Supported the idea that the motor concept associated with words is transmitted from one brain to another using the mirror neuron system.

Motor Mimicry Video

https://www.youtube.com/watch?v=dVFKVCQPIjo

Imitation• Two kinds of imitation:

• Automatic Imitation• Mirror neuron system contributes to

cognitive functioning.• Motor mimicry promotes prosocial attitudes

and behavior.• Motor Mimicry

• Both depend on the same psychological and neural processes.

• Both affected and controlled by the mirror neurons.

Theory of Mind"Theory of mind" refers to our ability to infer another person's mental state (i.e., beliefs and desires) from experiences or

their behavior.

Theory of Mind

According to simulation theory, theory of mind is available because we

subconsciously empathize with the person we’re observing and, accounting for relevant differences, imagine what

we would desire and believe in that scenario.

Schizophrenia Schizophrenia is a psychotic disorder in which personal, social, and occupational functioning deteriorate as a result of strange perceptions, unusual emotions, and motor abnormalities

(Comer, 2014).

• The discovery of “mirror neurons” provided an understanding of social cognition at a cellular level (Burns, 2006).

• The biological explanation of these abnormalities may be explained by an abnormal functioning of the mirror system (Burns, 2006).

Schizophrenia • The imitation and observation of others’

actions is an important component of social cognition, which is altered in schizophrenia (McCormick, 2012).

• Processing of social and emotional information has been shown to be disturbed in patients with schizophrenia (McCormick, 2012).

• Mirror neuron system forms the basis for the interpersonal experience and provides a basis for human empathy (McCormick, 2012).

Schizophrenia • One of the main barriers to recovery for

many people with schizophrenia are their profound and enduring difficulties with social interactions.

• Experience great difficulty forming relationships and maintaining employment

• Social impairments manifest in several different ways, ranging from paranoia of people intending to hurt them to withdrawing completely from social interactions.

Mirror Neurons Linked to Schizophrenia

• Neuroscientists at Vanderbilt University • Supported theory that an impaired ability

to imitate may underline the profound difficulty with social interactions that characterize schizophrenia.

• American Journal of Psychiatry• Researchers reported that people who

were asked to imitate simple hand movements exhibited abnormal brain activity in areas associated with the ability to imitate (Salisbury).

Study“The fact that patients with schizophrenia show abnormal brain activity when they

imitate simple hand gestures is significant because action imitation is a primary building

block of social abilities”.

• Katherine Thakkar

• The ability to imitate is present early in life and is crucial for learning how to navigate within the social world.

Study • Functional Magnetic Resonance Imagining

(fMRI): Maps levels of brain activity by measuring associated changes in the blood flow.

• The study uses fMRI to examine the brain activity of schizophrenic patients while they perform basic imitation tasks.

• Performed on sixteen medicated schizophrenic patients and sixteen healthy participants

• Confirmed that patients with schizophrenia have an impaired ability to imitate.

Autism Autism Spectrum Disorder (ASD) is a severe

neurodevelopmental disorder that is characterized by extreme unresponsiveness to people, severe

communication deficits, and rigid and repetitive behaviors, interests, and activities (Comer, 2014).

• Symptoms: • Lack of social skills• Absence of empathy• Language deficits• Poor imitation

• Dysfunction of mirror neuron system in individuals diagnosed with autism.

The Mirror Neuron Revolution: Explaining What Makes Humans

Social• Marco Iacoboni (Lehrer, 2008).

• Mirror neuron dysfunction has been associated with:• Social Deficits • Difficult time understanding mental states of others

•Motor Deficits• Language Deficits

The Anatomy of Autism

Inferior Frontal Gyrus• Reduced mirror neuron activity • Inability to assess intensions of others

Insula & Anterior Cingulate• Dysfunction of mirror neurons• Cause related symptoms (absence of empathy)

Angular Gyrus • Deficits that result in language difficulties • Structural changes in brain stem and cerebellum

The Anatomy of Autism

Mirror Neuron Dysfunction in Children with Autism

• Electroencephalogram (EEG): Measure brain waves

• Mu wave: Blocked when a person watches someone else perform the same action

• Study: (Ramachandran & Oberman, 2006)• High-functioning children with autism • Monitored mu waves as they made

voluntary muscle movements and then watched the same actions on video.

Mirror Neuron Dysfunction in Children with Autism

• Results: • Mu wave suppressed when completing a

voluntary muscle movement• Mu wave showed no suppression when

watching someone else perform the action.

Video

https://www.youtube.com/watch?v=_8WV1zAh9zU

ReferencesBlakeslee, Sandra. “Cells that Read Minds.” The New York Times. The New York Times Company, 10 Jan. 2006. Web. 19 April 2015,www.nytimes.com/2006/01/10/science/10mirr.html.

Burns, J. (2006). The social brain hypothesis of schizophrenia. World Psychiatry. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1525115/

Comer, R. (2014). Abnormal Psychology. (8th ed.) New York, NY: Worth Publishers.

Kalat, J. (2013). Biological Psychology. (11th ed.) Belmont, CA: Wadsworth.

Lehrer, J. “The Mirror Neuron Revolution: Explaining What Makes Humans Social.” Scientific American. 1 July 2008. Web. 19 April 2015,

http://www.scientificamerican.com/article/the-mirror-neuron-revolut/.

Marsh, J. (2012). “Do Mirror Neurons Give Us Empathy”. Greater Good Science Center. Web. 11. Apr. 2015,

http://greatergood.berkeley.edu/article/item_mirror_neurons_give_empathy.

References McCormick, LM.. (2012). Mirror neuron function, psychosis, and empathy in schizophrenia. NCBI Web: http://www.ncbi.nlm.nih.gov/pubmed/22510432.

Meltzoff, A.N. (2005). Imitation and other minds: The “Like Me” Hypothesis. In S. Hurley and N. Chater (Eds.), Perspectives on Imitation: From Neuroscience to Social Science. (Vol. 2), 55-77. Cambridge, MA: MIT Press.

“Mirror Neurons.” Wikipedia. Wikimedia Foundation, Jan. 2015. Web. 11. Apr. 2015, http://en.wikipedia.org/wiki/Mirror_neuron.

Ramachandran, V.S. & Oberman, L.M. (2006). “Broken Mirrors”. Scientific American Inc. Web. 12. 2015. Retrieved from:

http://cbc.ucsd.edu/pdf/brokenmirrors_asd.pdf.

Salisbury, David. “Brain Mapping Confirms Patients with Schizophrenia Have Impaired Ability to Imitate.”Vanderbilt Research. Vanderbilt University,

n.d. Web. 10 Apr. 2015, http://news.vanderbilt.edu/2014/03/schizophrenia-imitation.