1 / 34

Mirror Neurons

Mirror Neurons. Melissa Cinquina Briana Colantonio Mallory DelMauro Lauren Haviland Amanda McKelvey. Mirror Neurons. Mirror Neurons are:. I mportant in understanding actions of other people , learning new skills by imitation U nderlie cognitive disorders such as autis m

palila
Télécharger la présentation

Mirror Neurons

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Mirror Neurons Melissa Cinquina Briana Colantonio Mallory DelMauro Lauren Haviland Amanda McKelvey

  2. Mirror Neurons Mirror Neurons are: Important in understanding actions of other people, learning new skills by imitation Underlie cognitive disorders such as autism First ‘discovered’ in the 1980s and 1990s in premotor cortex of monkeys when observing hand-mouth motions and actions, and later studied in humans. Mirror Neurons might be: • “active both during preparation for a movement and while watching someone else perform the same or a similar movement,” (Kalat 243)

  3. Experiences with Mirror Neurons • Yawning • Autism • Automatic Imitation • Empathy

  4. Yawning • Why are yawns so contagious? • Cause for contagious yawning may be mirror neurons because of their correlation with imitation and empathy. • 2011 behavioral study shows that the emotional closeness to another individual directly affects the contagiousness of the yawn.

  5. Autism • Anatomical evidence shows that mirror neurons of those with autism spectrum disorders have thinner mirror neurons. • Mirror Neurons may not be the only cause for autism. • http://www.youtube.com/watch?v=xmEsGQ3JmKg 3.06-4.30

  6. Automatic Imitation • Individuals who observe a behavior attempt to perform a similar behavior. • http://www.youtube.com/watch?v=kU9MuM4lP18

  7. Empathy • Based on these pictures how do you feel? • Most people feel happy when they see the first picture and sad when they see the second. This is empathy. http://www.youtube.com/watch?v=xmEsGQ3JmKg (0-2.00)

  8. What parts of the Brain are active when mirror neurons are active? • Premotor cortex • Supplementary Motor Area • Primary Somatosensory Cortex • Inferior Parietal Cortex

  9. Premotor Cortex • Area of motor cortex • In frontal lobe of the brain • Projects directly into the spinal • cord • Subdivided into regions • Mirror Neurons found in area F5 in a monkey brain • Are both sensory and motor • May: Play a role in direct control of behavior, planning movement, spatial guidance of movement, sensory guidance of movement, understanding actions of others

  10. Supplementary Motor Area • Part of cerebral cortex • Controls movement • Is anterior to primary motor cortex • Neurons project into the spinal cord • May: play a role in direct control of movement, coordination of both sides of the body, control of movements that are internally generated, control of sequence of movements

  11. Primary Somatosensory Cortex • In the parietal lobe, • 3 areas discovered by Brodmann • 3, 1, and 2 • Area 3 subdivided, sensitive to somatosensory stimuli, • Area 1 and 2 relays texture information, size and shape

  12. Inferior Parietal Cortex • In the Parietal lobe • Integrates sensory information from different modalities • Comprises somatosensory cortex and dorsal stream of the visual system • Important in language processing • Processes information bout the sense of touch, visuospatial process

  13. Function of Mirror Neurons • It is hard to classify mirror neurons as having a unique singular functional role, rather they represent a mechanism that maps the pictorial description of actions carried out in the higher order areas of the brain. This matching mechanism may underlie a variety of functions including: • Understanding intention • Empathy • Human Self-Awareness • Language • Automatic Imitation • Theory of Mind

  14. Function of Mirror Neurons:Understanding Intention • Understanding intention- Inferior parietal lobe (IPL) • The IPL is an association cortex that integrates sensory information. • Study (by Fogassi et al. in 2005) recorded activity of 41 mirror neurons in the IPL of two rhesus monkeys. • Monkeys watched an experimenter either grasp an apple and bring it to his mouth or place it in a cup. • 15 mirror neurons fired when monkey observed “grasp to eat” but registered no activity while exposed to “grasp to place” condition • Remaining 4 other mirror neurons, reverse held true • Result: IPL neurons code the same act (grasping in this case) in a different way according to the final goal of the action in which the act is embedded • Helps link mirror neurons to understanding goals and intentions

  15. Function of Mirror Neurons:Empathy • Empathy- Anterior insula, anterior cingulate cortex, and inferior frontal cortex • Large number of experiments using fMRI, EEG, and MEG have shown that certain brain regions including the anterior insula, anterior cingulate cortex, and inferior frontal cortex are active when people experience an emotion: • o Disgust • o Happiness • o Pain • Also active when they see another person experiencing an emotion • These brain regions are not exactly the same as the ones which mirror hand actions, and mirror neurons for emotional states or empathy have not been described in monkeys yet • HOWEVER, Christian Keysers and colleagues have shown that people who are more empathic according to self-report questionnaires have stronger activations both in mirror system for hand actions and emotions. This provides more direct support for idea that mirror system is linked to empathy.

  16. Function of Mirror Neuron:Human Self-Awareness • Ramachandran argued that mirror neurons can not only help simulate other people’s behavior but can be turned “inward” • By turning inward, creates second-order representation of your own earlier brain processes • Could be neural basis of introspection and reciprocity of self awareness • Main point- the two co-evolved and create the representation of self

  17. Function of Mirror Neurons:Language • Language- inferior frontal cortex, close to Broca’s area • Functional MRI studies have reported finding areas homologous to monkey mirror neuron system in the hypothesized language regions of the brain (inferior frontal cortex, Broca’s area) • Leads to suggestions that human language evolved from a gesture performance/ understanding system in mirror neurons • Mirror neurons have been said to have the potential to provide a mechanism for • Action understanding • Imitation learning • Simulation of other people’s behavior • Rates of vocabulary expansion link ability of children to vocally mirror non-words acquire new word pronunciations • Study measured two participants gesturing words via hand gestures in game of charades • Analysis revealed that the mirror-neuron system of observer reflected pattern of activity of the activity in motor system of sender • This supported idea that the motor concept associated with words is transmitted from one brain to another using the mirror system

  18. Function of Mirror Neurons:Automatic Imitation • Automatic imitation is a covert form of imitation and distinct from spatial compatibility. • Refers to cases when an individual observes a body movement and deliberately performs a similar one • Rarely involves behavioral execution of matching responses • Subject to input modulation by attentional processes and output modulation by inhibitory processes • Mediated by long-term sensorimotor associations that cannot be altered directly by intentional processes • many researchers believe it is mediated by mirror neuron system

  19. Function of Mirror Neurons:Theory of Mind • Refers to our ability to infer another person’s mental state from experiences of their behavior • Simulation theory states the theory of mind is available because we subconsciously empathize with the person we’re observing and imagining what they would believe in a specific scenario. • Mirror neurons have been interpreted as the mechanism by which we simulate others in order to better understand them

  20. Dysfunction of Mirror Neurons Plays a Role in Autism: "Broken Mirror Hypothesis" 2005 University of California, San Diego study: The EEG recordings of 10, high-functioningautistic boys was compared to those of subjects’ controls. "Subjects were tested while they moved their own hands and while they watchedvideosvisual white noise, of bouncing balls, and of a movinghand.” The EEG data was analyzed for mu rhythmsuppression (a human brain wave pattern). The mu wave suppression was recorded in the control subjects both when they moved and when they watched others move. (Normal motor neuron activity). In contrast, the mirror neurons of the autistic subjects were only suppressed when they moved, not when they watched others move. Conclusion: A dysfunctional mirror neuron system may explain many of the social deficits that are characteristic of autism (i.e. lack of empathy, difficulty understanding others' actions and intentions).

  21. Further Support of Broken Mirror Hypothesis 2005 study by Marco Iacoboni and Mirella Dapretto of UCLA Experiment: "Used fMRi to image the brains of 20 children—10 with autism and 10 without—as the children viewed photographs of young people displaying different emotions. In the first five-minute scan, the children just observed the emotions; in the second five-minute scan, they were asked to imitate the expressions.” Results: Both groupsperformedthe tasks equally well, but children with autism showed no mirror neuron activity in the inferior frontal gyrus. Strong inverse relationship between symptom severity and mirror neuron activity: The more extremepeople's autism is, the lessactive their motor neurons will be.

  22. Anatomical Support for Broken Mirror Hypothesis • Studies have found that the mirror neuron related brain areas were thinner in adults with autism as compared to non-autistic adults. • The degree of thinning was directly related to symptom severity. (The thinner the brain areas, the more severe the autism.

  23. Possible Implications of Broken Mirror Hypothesis and More Research EEG can be used for earlier diagnosis of high functioning autistics, who are presently not diagnosed until age 3 or 4 or sometimes even later. Younger siblings of children who have been diagnosed have a greater genetic chance of also have the disorder, and therefore, they should definitely be tested this way. Earlier diagnosis will lead to earlier intervention. Present research is being done to see if mirror neurons are somehow involved in the ability to understand metaphors. If they are, a dysfunctional mirror neuron system may explain why autistic people usually have trouble understanding them, and they interpret them literally.

  24. Criticism of the Broken Mirror Hypothesis and a Conflicting Finding Overly simplistic: Mirror neurons alone cannot explain the social deficits in people with autism (may play supporting roles, but are most likely not the sole cause). None of the studies that support the Broken Mirror Hypothesis were explicit measures of mirror neuron activity. Mu-wave suppression cannot be used to accurately measure mirror neuron systems because experiments have found conflicting results. In a 2008 study, "Oberman and Ramachandran found typical mu-suppression for familiar stimuli, but not for unfamiliar stimuli, leading them to conclude that the mirror neuron system of children with ASD was functional, but less sensitive than that of typical children.”

  25. Another Conflicting Finding • In 2010, Ilan Dinstein and colleagues at NYU designed "a more sensitive test for mirrorneuron activIty.” • 13 autistic adults with the most severe form of autism, and 10 controls had to watch or perform a series of six different hand signals (i.e. rock, paper, scissors) while in a functional MRI scanner. • "In some trials they performed or watched the same hand movement over and over again; in others they performed or watched successions of different signals." • Findings: Brain areas linked to the mirror neuron system lit up in both autistic subjects and control subjects, whether they watched or performed a hand-movement. Also, "the mirror neuron activity quieted when both groups observed or performed the same signal over and over again, but not when they performed a succession of different movements.” • Importance: the mirrorneuron system may work normally in people with autism after all. Autism may instead be the result of "noisy brain networks" that don't communicate as predictably as those in normal people.

  26. Mirror Neuron System in Autism is Not Broken, Just Slowly Developing Study led by Dr. Christian Keysers in 2011 Findings: While most people have the strongest mirror activity while they are young, people with autism seem to have a weak mirror system in their youth. However, their mirror activity increases with age, is normal by about age 30, and is unusually high from then on. This improvement "may be related to increased capacity forsocial function or responsiveness to rehabilitative treatments."

  27. Bottom Line • Dysfunction of mirror neurons probably plays some kind of role in explaining at least some of the social impairments associated with autism, but until there is a more accurate way to assess this complex relationship, disagreements among researchers will surely continue. *Much more research needs to be done. .

  28. Research Articles http://www.youtube.com/watch?v=pToyPkrj u1o

  29. Background on fMRI • Magnetic Resonance Imaging (MRI) scanner • (fMRI) allows investigators to measure changes in blood flow to particular areas of the brain • When neurons in a particular brain area get more • active, they need more energy, and so more blood flows to those areas to help supply the energy and oxygen needed • So, blood flow= activity.

  30. Experiment • Either yawns played to them, normal breathing, or yawns that were scrambled up so that they had all of the same auditory properties of yawns, but didn't really sound like a yawn • Then rated how much they needed to yawn on a 4-point scale

  31. Results • Amount that they felt they needed to yawn was related to blood flow (remember= activity) in a particular area of the brain called the posterior inferior frontal gyrus • Contains mirror neurons • So mirror neurons may be responsible for yawning!

  32. Mirror Neurons in Stroke Patients • Stroke is a leading cause of disability among adults • Usually damage to extremities in one hemisphere • Intense physical therapy is often used, but for more severe cases, it does not always work • Another treatment option uses mirror neurons

  33. Stroke Treatment using Mirror Neurons • Mirror neurons are active when observing and executing actions • Representing observed actions in the motor cortex may be an alternative way to access the motor system after stroke • Regardless of impairments, it could rebuild voluntary motor actions

  34. References http://www.sciencedaily.com/releases/2005/04/050411204511.htm http://en.wikipedia.org/wiki/Mirror_neurons http://news.sciencemag.org/sciencenow/2010/05/a-crack-in-the-mirror-neuron-hyp.html http://seedmagazine.com/content/article/reflections_on_mirror_neurons/ http://www.sciencedaily.com/releases/2011/05/110503081159.htm http://web.ebscohost.com/ehost/detail?sid=b1f2edf1-72da-478c-94d9-6f528b1318a7%40sessionmgr14&vid=5&hid=11 http://www.psychologytoday.com/blog/ulterior-motives/200908/playing-yawn-tennis-mirror-neurons http://en.wikipedia.org/wiki/Yawn Kalat, J. (2013). Biological Psychology.Ohio; Cenage Learning. Aronson, E., Wilson, T.D., & Akert, R.M. (2013). Social Psychology. New Jersey: Pearson Education, Inc. http://web.ebscohost.com/ehost/detail?sid=89b0f92b-17c6-47d9-a346-c2e7c7c6d9a5%40sessionmgr13&vid=5&hid=11

More Related