A Unifying View of the Basis of Social Cognition by: Vittorio

Document Sample
A Unifying View of the Basis of Social Cognition by: Vittorio Powered By Docstoc
					A Unifying View of the Basis
    of Social Cognition
 Vittorio Gallese, Christian Keysers, and Giacomo Rizzolatti

                   Amanda Issa
                  Angela Arreola
                   Stacy Struhs
                    Focus of the Paper
• Provide a unifying neural hypothesis on
  how individuals understand the actions
  and emotions of others
• Claims:
     • Fundamental mechanism at the basis of the
       experiential understanding of others‟ is the
       activation of the MIRROR NEURON SYSTEM
• Survival and success depends on ability to
  thrive in complex social situations
  • Our ability to understand the feelings and/or
    actions of others
     • Derived from neural mechanisms that allow us to
       experientially comprehend actions and emotions of
       others as well as mimic them
• Conceptual reasoning is NOT the fundamental
  mechanism in understanding others
• Understanding ACTION and EMOTION
    Observer and the Observed
• The observer and the observed are the
  • Why? Because both are endowed with the
    same brain-body system
  • What does this mean? The brain has the
    ability to relate the first and third person
     • Example: Connecting “I do and I feel” to “He
       does and he feels”
                Action and Emotion
• Action
  • Neural system responds both when we
    execute a particular directed action AND
    when we observe someone else performing
    a similar action
• Emotion
  • Similar mechanism to action understanding
    that bridges the first and third person
            The Neural Mechanism
• Action Understanding
  • Producing meaning for the visual representation
  • Found in the ventral premotor cortex (area F5) of
    macaque monkeys
  • Same population of neurons responds when
    monkey performs specific goal directed action and
    when it observes another performing that same
  • The action is understood because the observer
    knows the outcome of the action
• Evidence for motor involvement in
  action understanding
    • Experiment: Evaluate the activity of F5 mirror
      neurons while monkeys understand the
      meaning of the action, without access to the
      visual features that trigger mirror neurons
                              First Study
• MN tested in two conditions
  • 1: Monkey could see ENTIRE action
  • 2: Same action but hand/object interaction
    blocked by screen
• Condition One   • Condition Two
                               Second Study
• F5 MN recorded when monkeys saw and heard executed
  noisy actions, only saw, or only heard.
• 15% of MN are responsive to
  presentation of actions accompanied by
  sounds also responded to the
  presentation of the sound alone!
    • Thus, „audiovisual MN‟ represent actions
      independently of whether these actions are
      performed, heard or seen.
    • Convincing?
       Compared to Human Data

• Observation of actions performed by others
  activates cortical motor representations
  • MN system formed by cortical network make up
     • Rostral part of inferior parietal lobule
     • Caudal sector of inferior frontal gyrus
     • Adjacent part of pre-motor cortex
                 Human MN System
• Responds to wider range of actions
  • Presence of object appears to be necessary
    to MN activation in monkeys, but mimed
    actions suffice to cause firing in human
  • Motor evoked potentials are faciliated
    when individual observes meaningless
    hand gestures as well as when a transitive
    action is observed
                Summary Thus Far
• Concurrent activation of similar parts of
  the motor system when we perform and
  when we observe a particular action
• Actions are understood by having the
  ability to mimic them and know the
  purpose of the action
                    Emotion Understanding
                                     • Mirror neurons as
                                       the mechanism by
                                       which we
                                       understand the
                                       actions of others
         QuickTime™ and a
TIFF (Uncompressed) decompressor
   are needed to see this picture.

                                       • Are others‟ emotions
                                         understood the same
                                       • Yes, via neurons in
                                         the insula
                                       • Disgust
                                 Monkey Data
• Monkey insula divided into two main
     • Anterior (visceral) Sector
     • Multimodal Posterior Sector
• Anterior Sector receives input from:
     • Olfactory and Gustatory centers
     • Anterior sectors of ventral bank of superior
       temporal sulcus
        • Where there are neurons that respond to faces
                          Monkey Data
• In addition, insula receives
  interoceptive afferents
  • Stimulation causes viscero-motor
                         Human Data
• Anterior insula activated by disgusting
  olfactory and gustatory stimuli, as in
• Also activated by disgusted facial
• Elicits viscero-motor responses
                                   Insular Lesions
• Patient NK, “disgust deafness,” left insular
      • Lack of response to visual and auditory stimulation
      • Reduced experiential sensation
          • Almost two standard deviations below normal

• Patient B, bilateral lesion
      • Deficits in recognition of disgusted facial expressions
      • Ingests food indiscriminately, even inedible items
                                  fMRI Data
• Disgusting Odorants and Movie Clips
      • Wicker et al, 2003
 Neural structures associated with Disgust

• Areas involved in experience and the
  perception of disgust.
  • Insula
• Fundamental motor structures involved in
  emotion expression and action control
  • Anterior Cingulate Cortex (ACC)
  • Basal Ganglia
           Structures involved in the
                    empathy of pain
• Used FMRI to show that these
  structures also mediate empathy for
  • Anterior Insula
  • ACC
     Towards a unifying neural hypothesis of the
                        basis of social cognition
• A bridge between ourselves and others
   • The understanding of basic aspects of social cognition depends on
     activation of neural structures normally involved in our own
     personally experienced actions or emotions.
       • Network of activation: Parietal and Premotor areas
• The ‘As If ’ Theory…
   • Do we just see or hear an action or emotion?
       • No, they postulated that side by side with the sensory descriptions of
         the observed social stimuli, internal representations of the state
         associated with these actions or emotions are evoked in the observer
         ‘as if” they were performing a similar action or experiencing a similar
         The Mirror Mechanism or „As if‟
• According to their view:
   • What is crucial for both the first and third person
     comprehension of social behavior is the activation of the
     cortical motor or visero-motor centers, the outcome of which,
     when activating downstream centers, determines a specific
     „behavior‟, be it an action or an emotional state.
• Further experiments…(Box 3)
   • In favor of this theory, studies found that actions belonging
     to the motor area of the observer (biting) are mapped on the
     observer‟s motor system
   • Likewise, actions that do not belong to this area (barking) are
     mapped out on the basis of their visual properties.
             The Mirror Mechanism
• Social cognition is not only thinking about the
  contents of someone else's mind…
  • Our brains have developed a basic functional
    mechanism ( mirror mechanism) which gives us
    experiential insight into other minds.
• This mechanism provides the first unifying
  perspective of the neural basis of social
   Problems with other theories of
          understanding emotion
• Damasio and coworkers:
  • “The feeling of emotions depends on the
    activation of the somatosensory cortices in the
    broader sense, and of the insula in particular.”
  • Differs from the „as if‟ theory presented by
    authors, in regards to the underlying
     • Authors indicate motor and viscero-motor centers as
       central areas involved, not just the somatosensory area.
                 Discussion Questions
• Is the mirror system for actions and for
  emotions, functioning normally in people with
  autism, whose understanding of other minds
  is impaired?
   • No, they have observed abnormalities in the MNS
     system as well as abnormalities in other areas in
     the brain.
• Baby‟s first steps
   • http://www.youtube.com/watch?v=ua3P81gjdKg

Shared By: