1. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Distinguishing between self and other: How shared are shared representations? Marcel Brass MAX PLANCK INSTITUTE FOR HUMAN COGNITIVE AND BRAIN SCIENCES DEPARTMENT OF COGNITIVE NEUROLOGY LEIPZIG

2. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Observation and execution of action are closely linked Cognitive psychology – movement observation has a strong influence on movement execution (Brass et al., 2000, 2001, Stuermer et al., 2000) Social psychology – chameleon effect (Chartrand & Bargh, 1999) Brain imaging – activation of motor related areas by action observation (e.g. Grezes & Decety, 1999) Neurophysiology – mirror neurons (e.g. Rizzolatti & Craighero, 2004)

3. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 The direct matching hypothesis Action observation leads to an activation of an internal motor representation.

4. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Open questions Why dont we imitate all the time? Why dont we confuse internally generated and externally triggered motor representations?

5. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Neuropsychological findings Luria (1966) – prefrontal patients show echopractic response tendencies Lhermitte et al. (1986), DeRenzi et al. (1996) – patients with prefrontal lesions show overt imitative behavior

6. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 The imitation-inhibition task congruent incongruent baseline Brass et al. (2000)

7. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Brass et al. (2000) + + Lift the index finger when a `1` appears and the middle finger when a `2` appears. The imitation-inhibition task

8. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Results Brass et al. (2000) inconbase con

9. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Patients 16 patients with frontal lesions of different etiology and lesion site 14 patients with posterior lesions (temporal, parietal) 16 age-matched controls

10. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Results Brass et al. (2003) Imitation-inhibition task frontal posteriorcontrol * * interference score: incongruent errors (%) – congruent errors (%)

11. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Conclusions Patients with frontal lesions have problems to inhibit imitative response tendencies.

12. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Functional mechanisms involved in the inhibition of imitative behavior Hypothesis 1.The inhibition of imitative behavior involves general inhibitory mechanisms. 2.The inhibition of imitative behavior involves specific mechanisms related to the distinction of self-generated and externally triggered motor representations.

13. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Experimental design ten healthy right handed participants the imitation-inhibition task functional Magnetic Resonance Imaging (fMRI)

14. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Imitation-inhibition task Incongruent vs. congruent Brass, Derrfuss & von Cramon (2005) 1 2 1 2 anterior fronto-median cortex (aFMC) temporo-parietal junction area (TPJ)

15. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 The functional role of the anterior fronto-median cortex and the TPJ –sense of agency (e.g. Farrer et al., 2003) –perspective taking (Ruby & Decety, 2001, 2003) –out of body experience (Blanke et al., 2002)

16. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Conclusions The inhibition of imitative behaviour seems to involve mechanisms related to self- other distinction.

17. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 The mirroring of contextual information Are environmental constraints mapped onto the observers motor representation?

18. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Prediction Observing a physical restraint in another person should restrain the observer.

19. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Paradigm no restraint corresponding restraint non-corresponding restraint

20. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Demonstration

21. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Results

22. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Alternative hypothesis The slowing effect is due to higher perceptual difficulty in the corresponding restraint condition.

23. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Test no restraint corresponding restraint if a 1 appears if a 2 appears Stimuli Responses

24. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Results

25. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Summary There is an automatic tendency to imitate observed behaviour. Prefrontal patients have problems to inhibit imitative response tendencies. The inhibition of imitative behaviour involves functional mechanisms related to self-other distinction. Not only the action itself is mapped onto the observers motor representation but also environmental constraints.

26. Max Planck Institute for Human Cognitive and Brain Sciences04.2006 Roman Liepelt Stephanie Spengler Michael Steinborn Harold Bekkering Jan Derrfuss Wolfgang Prinz D. Yves von Cramon