Formal terms 1 Object-learning Social imitation Emulation - PDF document

24/03/2015 Formal terms 1 Object-learning Social imitation • Emulation • Mimicry – copying only an action form • Affordance learning What is imitation? • Overimitation – copying unnecessary actions 2 Antonia Hamilton UCL 3 Goal Directed Imitation Participants • 3-6 year olds imitate goals Autistic Spectrum not means Control Difference Disorder • Revealed by hand errors on Number 26 25 contralateral trials Chronological 8 y 2 m 4 y 2 m Sig • Good imitation on all other Age (2 y 1 m) (7 m) p < 0.001 trials Verbal Mental 4 y 3 m 4 y 9 m n.s. Age (1 y 2 m) (1 y 0m) p= 0.11 • Do children with ASD show Theory of 3.2 / 13 7.0 / 13 sig the same pattern of errors? Mind Score (2.9) (3.4) p < 0.01 Bekkering, et al, 2000 Gattis et al, 2002 Goal directed imitation Normal emulation in autism Ipsi-contra p<0.001, dots p=0.023, interaction p=0.034 Good performance on: Group p>0.6 • goal directed imitation (Hamilton et al) • intention imitation (Aldridge et al, asd 4 Carpenter et al) control hand errors • Goal imitation (Hobson & Lee) 2 0 ipsi contra both ipsi contra both dots absent dots present • Both groups replicate Bekkering et al • No problems with goals in children with ASD 1

24/03/2015 So far … Over-imitation • Copying of visibly unnecessary actions Object-learning Social imitation • Present in toddlers (and adults) 3 • Emulation • Mimicry – copying only • Often studied with novel / complex objects an action form • Affordance learning • Overimitation – copying unnecessary actions https://www.youtube.com/watch?v=20Smx_nD9cw Social overimitation Results • Familiar objects (no causal reasoning) Overimitation … • Present for familiar objects • Older children (n=94, age 5-8 years) • Increases with age • Judge rationality – was it sensible or silly? • Increases with social cues • Increases when children % overimitation judge action is ‘silly’ Overimitation is SOCIAL Marsh et al, PlosOne, 2014 Overimitation in autism Results Group ASC CA- match VMA- match p=0.0018 Good explicit n 31 30 30 rationality p<0.0001 discrimination 9.4 ± 2.3 8.66 ± 2.0 6.0 ± 1.3 p=0.024 Age (5.2 - 13.6) (4.9 - 12.7) (4.2 - 8.6) p=0.0076 66.7 ± 21.5 94.5 ± 19.9 65.9 ± 20.6 BPVS raw (33 - 119) (57 - 137) (35 - 122) 9.2 ± 4.6 27.6 ± 4.7 24.1 ± 4.1 SAS (0 - 19) (10 - 39) (17 - 32) Theory of Mind 57.7 ± 28.7 not collected not collected (%) (0 - 100) Poor explicit 25.5 ± 4.9 SCQ scores not collected not collected rationality (15-33) discrimination Marsh et al, 2013 2

24/03/2015 So far … Brain systems for imitation Object-learning Social imitation Medial Prefrontal Cortex - Theory of Mind 3 • Emulation • Mimicry – copying only an action form • Affordance learning • Overimitation – mPFC aIPS copying unnecessary 7 actions IFG Mirror neuron systems Anterior Intraparietal sulcus & Inferior frontal gyrus fMRI of action observation in ASD Normal goal responses in aIPS 18 adults with ASD Hands > Shapes 19 age & IQ matched typical adults response in left anterior rational irrational intraparietal sulcus in both Repetition suppression for goals in aIPS for both Marsh & Hamilton, NeuroImage 2010 Observation of irrational Summary action in autism Goal emulation • Normal behavior 7 mPFC • Normal brain activity 3 aIPS in aIPS • Normal mirror neurons Overimitation • Reduced behavior • Different brain Marsh & Hamilton, 2011 activity in mPFC 3

24/03/2015 Implications Cognitive model: STORM (Social Topdown Response Modulation) Children with autism can imitate object-actions and when instructed Need help with Social mPFC response - When to imitate IPL modulation - Who to imitate IFG LO When do typical people imitate? Visuo-motor mapping - Gaze as a social cue mirror neuron system (Rizzolatti) perception-behaviour expressway (Bargh) Wang & Hamilton, FiHNS, 2012 Measuring mimicry in adults Does eye contact modulate mimicry? mimicry direct gaze averted gaze Reaction Time Congruent Incongruent mimicry no mimicry Wang, Newport & Hamilton, Biology Letters, 2010 So far The technology • Being watched increases imitation projector magnetic Good ecological validity marker on head & hand Polhemus Liberty magnetic motion tracker interactive avatar on projection screen participant participant graphics rendering computer data recording computer Good experimental control 4

24/03/2015 Take home message Autism@icn group – participant recruitment Thank you Paul Forbes Sylvia Pan Imitation is complex Harry Farmer - More than one behaviour Jo Hale - More than one brain network UCL Lauren Marsh - Social imitation matters Yin Wang - Control of (social) imitation differs in Amy Pearson autism Lorcan Kenny Liz Renner Lots more to do … Indu Dubey www.antoniahamilton.com 5