Motivating Questions Social Cognition and the Mirror How do our brains perceive the Neuron System of the Brain mental states of others despite their inaccessibility? How do we understand the actions, emotions and the intentions of others? Rationally? Intuitively? Jaime A. Pineda, Ph.D. Cognitive Neuroscience Laboratory How do we understand first- COGS1 class and third-person experiences? Classic Explanation A Different Perspective Theory-Theory (argument from analogy; disembodied Simulation Theory knowledge; visual hypothesis) (Direct-matching hypothesis; embodied knowledge) Map visual information onto Involves striate, extrastriate, motor representations of the inferotemporal lobe and same action superior temporal sulcus, among others Mirroring systems bridges between perception and action that allow for simulation Mirror neurons EEG Mu rhythms A Different Perspective The Mirror Neuron System 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 Iacoboni and Dapretto, Nature Reviews, 2006,7:942-951 1 Biological Motion Biological Motion Perception: Monkeys Visual system's ability to Gender recover object information Activity engaged in Perret and colleagues from sparse input Emotional state (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 Brain Circuit for Social Perception (SP) An area in the superior • SP is processing of temporal sulcus (STS) in information that results in humans responds to the accurate analysis of biological motion the intentions of others • STS involved in the Other areas do as well, processing of a variety of including frontal cortex, social signals SMA, insula, thalamus, amygdala Grossman et al. J. Cog. Neurosci., 2000, 12(5), 711-720 Allison et al., Trends in Cog. Sci., 2000, 4, 267-272 Mirror Neurons Mirror Neuron Activity 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 2 Perception-to-Action Mapping Selectivity Understanding Intentions Congruent Logically-Related Grasping Mimicking (effector dependent) (effector independent; 2X) Perception Action Umilta et al. Neuron, 2001, 32: 91-101 Functional Significance Characterizing the System Response facilitation generalizability? motivational significance? Mimicry biological realism? Simulation intentionality? social relevance? Imitation learning anthropomorphism? Understanding actions transitive/intransitive actions? learning? Understanding intentions Empathy Theory of Mind Language MNS activity No MNS Activity The Mirror Neuron System Mu Rhythm 8-13 Hz oscillation over sensorimotor cortex Normal Oscillation Self Action Observed Action Iacoboni and Dapretto, Nature Reviews, 2006,7:942-951 3 Frequency Analysis of Mu Rhythm Does Mu Suppression Reflect Mirror Activity? (8-13 Hz) P Baseline o (10-14 Hz) w e Move r Observe Frequency Imagine Pineda et al., IEEE Trans. Rehab. Engr., 2000, 8(2): 219-222 Action Observation and Social Interaction Experimental Paradigm Measured mu power (2 min of EEG) in normals (n=20) ages 18-34 (mean=21.1, SD=3.40 ) under different To what degree do mu rhythms, like mirror neurons, observation conditions: reflect social interaction? Non-interacting Social Action - Spectator Social Action - Interactive Visual white noise Engaged in continuous performance task during observation Oberman et al., Social Cognitive and Affective Neuroscience, 2007, 2, 62-66 Non-interacting Social Action - Spectator Results 4 n o i 3.5 t c a r 3 e t n I 2.5 l a i 2 c o S 1.5 f o Social Action - Interactive e 1 e r g 0.5 e D 0 Non-Interacting Social Action, Social Action, Spectator Interactive 4 Results Autism Spectrum Disorder (ASD) Problems in the following domains: 0.1 Social ability C3 CZ C4 0 intelligence Language acquisition -0.1 -0.2 -0.3 Social Action, Interactive Social Action, Spectator Non-Interacting -0.4 Common Characteristics Autism: A Dysfunctional Mirror System? Impairment in social play and imagination No common underlying Impaired ability to initiate conversations with others mechanism has been Repetitive behaviors identified Impaired sustained attention Deficits in imitation learning – Trouble Imitating others Rogers and Pennington, 1991 Deficits in mirror neuron system Difficulty interpreting actions and intentions of others - Williams et al., 2001 Absence of empathy Hypothesis Experimental Paradigm Measured mu power (2 min of If mu rhythms reflect MNS activity and the capacity to EEG) in normals (n=12) and understand actions as well as learn through imitation, autistics (n=10) under different then autistics should show differences in mu rhythms conditions: compared to controls Self-movement of hand Watching video of someone moving their hand Watching a video of a ball moving up and down Oberman et al., Cog. Brain Res. 2005, 24: 190-198 Oberman et al., Brain Res Cogn Brain Res. 2005, 24(2):190-8. 5 Results Results Oberman et al., Neuropsychologia, 2008 Jan 19 [Epub ahead of print] Creating a Temporary “Autistic” Brain Method Do sensorimotor mu rhythms reflect downstream Measured EEG mu power in typically developing modulation from cells in premotor cortex? adults (n=8) under different conditions before and after IFG stimulation Observation of movement (4 videos) RATIONALE Simple (hand movements) and complex (social If mirror neurons in IFG are involved in the direct interactions) modulation of mu rhythms, then temporary inhibition Baron-Cohen’s Eyes Task of these neurons should prevent suppression of mu Emotion and gender discrimination rhythms and cause “autistic-like” behaviors. 1 Hz rTMS (5 min at ~ 40-50% MEP threshold) targeted at left IFG Pineda et al., in prep 6.