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Transcript of Social Cognition and the Mirror Neuron System of the Brain Jaime A. Pineda, Ph.D. Cognitive...
Social Cognition and the Mirror Neuron System of the Brain
Jaime A. Pineda, Ph.D.
Cognitive Neuroscience Laboratory
COGS1 class
Motivating Questions
How do our brains perceive the mental states of others despite their inaccessibility?
How do we understand the
actions, emotions and the intentions of others?
Rationally? Intuitively?
How do we understand first- and third-person experiences?
Classic Explanation
Theory-Theory (argument from analogy; disembodied
knowledge; visual hypothesis)
Involves striate, extrastriate, inferotemporal lobe and superior temporal sulcus, among others
A Different Perspective
Simulation Theory (Direct-matching hypothesis; embodied knowledge)
Map visual information onto motor representations of the same action
Mirroring systems bridges between perception
and action that allow for simulation
Mirror neurons EEG Mu rhythms
A Different Perspective
Simulation Theory (Direct-matching hypothesis; embodied
knowledge) Map visual information onto
motor representations of the same action
Mirroring systems bridges between perception and
action that allow for simulation Mirror neurons EEG Mu rhythms
The Mirror Neuron System
Iacoboni and Dapretto, Nature Reviews, 2006,7:942-951 Pineda, Beh & Brain Functions, 2008, 4, 47
Biological Motion
Visual system's ability to recover object information from sparse input
Gender Activity engaged in Emotional state
Biological Motion Perception: Monkeys
Perret and colleagues
(1989; 1990; 1994)
Cells in superior temporal polysensory area (STPa) of the macaque temporal cortex appear sensitive to biological motion
Oram & Perrett, J. Cog. Neurosci., 1994, 6(2), 99-116
Biological Motion Perception: Humans
An area in the superior temporal sulcus (STS) in humans responds to biological motion
Other areas do as well, including frontal cortex, SMA, insula, thalamus, amygdala
Grossman et al. J. Cog. Neurosci., 2000, 12(5), 711-720
Brain Circuit for Social Perception (SP)
Allison et al., Trends in Cog. Sci., 2000, 4, 267-272
• SP is processing of information that results in the accurate analysis of the intentions of others
• STS involved in the processing of a variety of social signals
Mirror Neurons
A specific class of neurons that discharge both when the monkey performs an action and when it observes a similar action done by another monkey or an experimenter
Found in: area F5 (homolog of Broca’s
area); 10-20% inferior parietal cortex (PF/7b)
Activated by: Goal directed actions
(reaching, grasping, holding) Observation of similar actions
performed by “biological” agents
Di Pellegrino et al., Exp. Brain Res., 1992, 91, 176-80
Rizzolatti et al., Cogn. Brain Res., 1996, 3:131-141
Mirror Neuron Activity
Perception-to-Action Mapping Selectivity
Action
Logically-Related(effector independent; 2X)
Congruent(effector dependent)
Perception
Understanding Intentions
Umilta et al. Neuron, 2001, 32: 91-101
Grasping Mimicking
Inferior parietal
lobule
Superior temporalsulcus
Inferior frontal gyrus
Sensorimotorcortex
Mirror Neuron System
Response facilitation Mimicry Simulation Imitation learning Understanding actions Understanding intentions Empathy Theory of Mind Language
Functional Significance
MNS activity No MNS Activity
intentionality?anthropomorphism?
biological realism?motivational significance?
transitive/intransitive actions?
generalizability?
Characterizing the System
learning?
social relevance?
Mu Rhythm
8-13 Hz oscillation over sensorimotor cortex
Normal Oscillation Self Action Observed Action
Frequency Analysis of Mu Rhythm
Power
Frequency
(8-13 Hz)
(10-14 Hz)
Pineda et al., IEEE Trans. Rehab. Engr., 2000, 8(2): 219-222
Does Mu Suppression Reflect Mirror Activity?
Baseline
Move
Observe
Imagine
Action Observation and Social Interaction
To what degree do mu rhythms, like mirror neurons, reflect social interaction?
Oberman et al., Social Cognitive and Affective Neuroscience, 2007, 2, 62-66
Measured mu power (2 min of EEG) in normals (n=20) ages 18-34 (mean=21.1, SD=3.40 ) under different observation conditions:
Non-interacting Social Action - Spectator Social Action - Interactive Visual white noise
Engaged in continuous performance task during observation
Experimental Paradigm
Non-interacting Social Action - Spectator
Social Action - Interactive
0
0.5
1
1.5
2
2.5
3
3.5
4
Non-Interacting Social Action,Spectator
Social Action,Interactive
De
gre
e o
f S
oc
ial
Inte
rac
tio
nResults
Results
Autism Spectrum Disorder (ASD)
Problems in the following domains: Social ability Language development Behavior
Common Characteristics
Impairment in social play and imagination Impaired ability to initiate conversations with others Repetitive behaviors Impaired sustained attention Trouble Imitating others Difficulty interpreting actions and intentions of others Absence of empathy
Autism: A Dysfunctional Mirror System?
No common underlying mechanism has been identified
Deficits in imitation learning – Rogers and Pennington, 1991
Deficits in mirror neuron system - Williams et al., 2001
Hypothesis
If mu rhythms reflect MNS activity and the capacity to understand actions as well as learn through imitation, then autistics should show differences in mu rhythms compared to controls
Oberman et al., Cog. Brain Res. 2005, 24: 190-198
Experimental Paradigm
Measured mu power (2 min of EEG) in normals (n=12) and autistics (n=10) under different conditions:
Self-movement of hand
Watching video of someone moving their hand
Watching a video of a ball moving up and down
Oberman et al., Brain Res Cogn Brain Res. 2005, 24(2):190-8.
Results
Results
Oberman et al., Neuropsychologia, 2008 Jan 19 [Epub ahead of print]
Creating a Temporary “Autistic” Brain
Do sensorimotor mu rhythms reflect downstream modulation from cells in premotor cortex?
RATIONALEIf mirror neurons in IFG are involved in the direct modulation of mu rhythms, then temporary inhibition of these neurons should prevent suppression of mu rhythms and cause “autistic-like” behaviors.
Method
Measured EEG mu power in typically developing adults (n=8) under different conditions before and after IFG stimulation
Observation of movement (4 videos) Simple (hand movements) and complex (social
interactions) Baron-Cohen’s Eyes Task
Emotion and gender discrimination
1 Hz rTMS (5 min at ~ 40-50% MEP threshold) targeted at left IFG
Eyes Task
Results
0
5
10
15
20
25
30
Emotion Recognition Gender Recognition
Rea
ctio
n T
ime
(sec
)
Before IFG stimulation After IFG stimulation
0
0.2
0.4
0.6
0.8
1
Emotion Recognition Gender Recognition
Acc
ura
cy
Before IFG stimulation After IFG stimulation
Reaction Time Accuracy
Results
IFG STIMULATION
-0.1
-0.08
-0.06
-0.04
-0.02
0
0.02
0.04
0.06
0.08
0.1
C3 C4 C3 C4
SIMPLE COMPLEX
MOVEMENT TYPE
MU
SU
PP
RE
SS
ION
PRE
POST
Frontoparietal areas in an ASD brain may be underconnected
If we change the dynamics of the sensorimotor mu oscillations,
And these oscillations are functionally linked to the MNS network (IFG, IPL, STS),
Then we may change functional connectivity and recover MNS engagement,
Leading to positive changes.
IPL
STS
SM Cortex
IFG
Plasticity Induced Rehabilitation Training
Reversing Social Deficits in Autism?
Training 30 min x 3/week x 10 weeks HF ASD: 7-17 yr olds; n=20
Experimental/Control groups Mu activity above threshold (E) EMG activity below threshold
(E/C)
Pineda et al., Research in ASD, 2008
Pre/Post Assessments
Verification of diagnosis (IQ, ADI, ADOS)
Quantitative EEG (QEEG) Test of Variable Attention (TOVA) Imitation ability (Apraxia imitation test) Mu suppression index (MSI) Autism Treatment Evaluation
Checklist (ATEC) Neuroimaging (fMRI, fcMRI)
Facial Emotions (n-back) Eyes Emotion Task - ToM
Physical Causation - ToM
Mental Attribution- ToM
Pre/Post Assessments
R2 = 0.7068
0
50
100
150
200
250
300
350
400
0 2 4 6 8 10 12 14 16 18
SESSIONS
(HIT
S/M
IN)*
TH
RE
SH
R2 = 0.7673
0
50
100
150
200
250
300
350
400
0 5 10 15 20 25
SESSIONS
(HIT
S/M
IN)*
TH
RE
SH
ASD
TD
Behavioral Performance
Mu Suppression Index
MU SUPPRESSION INDEX
-0.1
-0.08
-0.06
-0.04
-0.02
0
0.02
0.04
0.06
HAND SOCIAL HAND SOCIAL
PRE-TRAINING POST-TRAINING
LO
G [
CO
ND
ITIO
N/B
AS
EL
INE
]
CONTROLS
EXPERIMENTALS
EEG Coherence
Sustained Attention
Reduction trend in ADHD score for
experimental group
Autism Treatment Evaluation Checklist
Functional connectivity
Diffusion Tensor Imaging structural
functional
Future: Neuroimaging Techniques
A Fundamental Organizational Feature of the Brain?
“Understanding others as intentional agents may be grounded
in the relational nature of our interactions with the world”
Beyond understanding actions emotions: the root of empathy? sounds and other senses language
Other problems in “mirroring” Aberrant imitation learning: addiction?
What Is It Like To Be…?
Thomas Nagel, The Philosophical Review 83 (1974).
Can aspects of subjective experience be reduced to brain activity?
Collaborators and Students
Vilayanur Ramachandran
Lindsay Oberman Eric Altschuler Andrey Vankov Bill Skinner Chulie Ulloa Brendan Allison Ed Hubbard Joe McCleery Erin Hecht David Brang Scott Carey
Adrienne Moore Rajiv Rao Chris Robinson Hanie Elfenbein Alex Bressler Steven Thurman Jena Davis Dong Suk Christa Futagaki Judith Kaye Lee Edwards Ralph-Axel Mueller Brandon Keehn
Oriana Clark Jia-Min Bai Derrick Asher Dane Chambers Matt Earhardt Heather Pelton Alicia Trigerio Albert Ayala Stephen Johnson Steve Gilmore Nick Pojman Kelly Head