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Was that me? Probing the neurocognitive basis of the sense of agency

Was that me? Probing the neurocognitive basis of the sense of agency. Matthis Synofzik Dept. of Neurodegeneration Hertie-Institute for Clinical Brain Research University of Tübingen Germany. Definitions. Sense of agency= the registration that we are the initiators of our actions

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Was that me? Probing the neurocognitive basis of the sense of agency

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  1. Was that me? Probing the neurocognitive basis of the sense of agency Matthis Synofzik Dept. of NeurodegenerationHertie-Institute for Clinical Brain ResearchUniversity of TübingenGermany

  2. Definitions Sense of agency= the registration that we are the initiators of our actions - does not require: - any direct phenomenal awareness (≠ Gallagher, 2007) - any meta-representations of self-agency (Frith, 2005; Stephens & Graham (2000) - the conceptual ability to register self-agency (de Vignemont & Fourneret, 2004) ≠ Sense of body ownership= the sense that my body is moving regardless of whether the movement is voluntary or involuntary - does not require: - any active movement - any efferent action information/forward models

  3. A multifactorial two-step account of the sense of agency Hypothesis: The sense of agency is a complex supramodal, internal representation of largely heterogeneous functional and (self-)representational levels. Charlie‘s action! My action! • Judgement of agency • = conceptual, interpretative representation • - specific belief formation about the • origins of the sensation • essentially an ad hoc theorizing about • oneself as influenced by contextual • cues and belief states Self-caused Not self-caused • Feeling of agency • = preconceptual, perceptual representation • - weighting and integration of different • sensorimotor authorship cues: • congruency= experience of self-agency by coherent flow of action processing • incongruency= action as peculiar/strange Synofzik, Vosgerau & Newen, Consc & Cog, 2007

  4. The feeling of agency (FoA) • Hypothesis: • The feeling of agency is produced by a gradual and highly plastic subpersonal weighting process of different action-related perceptual and motor cues. • A sensory prediction of one’s movements is one of the factors entering the FoA. • This prediction is adaptable by sensory feedback. ? Synofzik et al., J Neurophysiol, 2006

  5. Condition 1: Feedback Trials 90° PD Pointing Direction Visual Feedback 0° Synofzik et al., J Neurophysiol, 2006

  6. Condition 1: Feedback Trials 90° PD Pointing Direction PPD Perceived PD Visual Feedback 0° Synofzik et al., J Neurophysiol, 2006

  7. Condition 2: Perceptual Control Trials 90° PD Pointing Direction PPD Perceived PD 0° Synofzik et al., J Neurophysiol, 2006

  8. Condition 2: Perceptual Control Trials 90° PD Pointing Direction PPD Perceived PD 0° Synofzik et al., J Neurophysiol, 2006

  9. Results normal subjects • Subjects‘ perception of their hand movements • adapted by 15° in the direction of visual feedback rotation. • 2) This effect was independent from the fact whether • visual feedback was presented immediately before or not. (i) We use external agency cues – especially visual feedback- to inform the SoA. (ii) The SoA per se, however, is internal, supramodal in nature ( main thesis!). • An „internalization“ of one‘s own „external“ reafferences 3) We did not test for qualitative, dichotomic agency judgements („Was the movement you have seen caused by yourself or not?“), but for the gradual amount o afferent information for which self-agency is claimed („Indicate the movement you have performed“).  measure of the FoA 4) The only partial adaptation reflects a fundamental dilemma when interacting with the world: Don‘t rely too much on exafferent feedback vs. use this feedback for recalibrating our sensory predictions/ the FoA. 5)  The FoA should not be seen in terms of a static dichotomy between self-produced and not self-produced, but as a result of a gradual and – as shown here – highly plastic process that constantly allows the subject to redefine the causal relations to its surroundings. Synofzik et al., J Neurophysiol, 2006

  10. Results schizophrenia patients • 1) Schizophrenia patients over-rely on external reafferences. • fail if external feedback is temporarily not available or ambigous 2) Internal predictions for perception per se are not impaired. • Delusions of influence might result from an insufficient exploitation of internal predictions/proprioception within the multi-modal integration of action-related information.  Problem of integrating multimodal sensorimotor authorship information (rather than of a problem of the internal prediction per se). Feedback Trials Perceptual Control Trials Synofzik et al., in preparation

  11. Interim summary Thesis: The feeling of agency is the result of weighting and integrating different sensorimotor authorship cues. Experiment 1 (normal subjects) 2. 1. Synofzik, Vosgerau & Newen, Consc & Cog, 2007

  12. Interim summary (cont`) Thesis: The feeling of agency is the result of weighting and integrating different sensorimotor authorship cues. Experiment 2 (schizophrenia patients) Synofzik, Vosgerau & Newen, Consc & Cog, 2007

  13. How can we explain delusions of control? Thesis: Delusions of control are best accounted for by a two-step account. • Impairment in belief formation (JoA): • an alien experience is not accepted as a strange experience. • a delusional agency hypothesis about the perceived fact is formed out. • (iii) this is maintained despite different stored encyclopedic knowledge about their behaviour and despite the testimony of others. Synofzik, Vosgerau & Newen, Consc & Cog, 2007

  14. Shortcomings in present research on the SoA • Most experiments investigating the SoA explore the level of JoA, but not the level of FoA. • The diversity of neural correlates of the SoA results from differences of conceptual notions of the SoA. Daprati et al., 1997; Franck et al., 2001; Farrer et al., 2003, David et al., 2007

  15. Conclusions Overall thesis: The sense of agency is a complex supramodal, internal representation of largely heterogeneous functional and (self-)representational levels. 1) The basic feeling of agency is produced by a gradual and highly plastic subpersonal weighting process of different action-related perceptual and motor cues. 2) This preconceptual core is further processed by conceptual capacities and belief stances to form a judgement and attribution of agency. 3) The extent to which the feeling and the judgement of agency, respectively, contribute to the overall SoA depends on the context and task requirements (e.g. ambiguity, complexity, context conditions, psychological and social situation). 4) Thus, the SoA is a dialectic combination of both, bottom-up processes (as emphasized by Frith et al., 2000) and top-down processes (as emphasized by Stephens & Graham, 2000).

  16. Cognitive Neuroscience Philosophy Gottfried Vosgerau Axel Lindner Albert Newen Peter Thier Thank you!

  17. The gradual contributions of the two agency representations unstable, ambigous circumstances SoA JoA SoA FoA stable, unequivocal circumstances

  18. Limitations of the comparator model:1) it‘s not sufficient • (i) can explain a peculiar perceptual experience, but not the actual agency attribution (especially not the exact external agent) • (ii) even in cases of mismatch the action is sometimes attributed to oneself • (iii) even when sufficient information for an internal comparison, i.e. efference copy and visual feedback, is given, persons might not be able to self-attribute their own actions (e.g. patients with impaired proprioceptive feedback, Fourneret et al., 2002) • (iv) there are other sources of peculiar action experiences and of self-attribution, which do not even need to involve motor actions at all

  19. Limitations of the comparator model:2) it‘s not necessary Wegner et al., 2004 Aarts et al., 2005 Perceptual self-attribution Priming

  20. SoA ≠ sense of initiation • - the representational content of the SoA is not only determined by the action initiation per se • - but also refers to the guidance and consequences of one’s actions and the causal relation between action intention, action performance, and action consequences • (ii) patient GL has a SoI, but not a SoA Agency of an action Relates to bodily consequences and/or action effects Action initiation Independent from any sensory bodily consequences or sensory effects ≠

  21. SoA ? How should we individuate the SoA ? SoA ? SoA ?

  22. Outlook 1) Test the differential contributions of the various factors to the FoA. • Dissociate FoA and JoA within one experiment (behavioural/neuroimaging). And, in a next step: double dissociate FoA, FoO, JoA, and JoO. 3) Explore pathological disruptions of agency for the specific factor/level that is disrupted (e.g. alien hand; anosognosia for one’s own hemiparesis, anarchic hand).

  23. A multifactorial two-step account of the sense of ownership Hypothesis: Also the sense of ownership is a complex supramodal phenomenon of largely heterogeneous functional and (self-)representational levels. „alien hand“ Rubber hand illusion( e.g. Haggard/Tsakiris)

  24. 1. The explanation of the sense of ownership Gallagher, TICS, 2000; similar in Gallagher, 2005. • Critique: • There is no need for any comparator for having a sense of ownership. • There is not even the need for any intentional stance or for multimodal feedback. • Unimodal sensory feedback (e.g. proprioception) can be sufficient

  25. 2. The explanation of the sense of agency Gallagher, TICS, 2000; similar in Gallagher, 2005. • Critique: • There is no information about the actual movement and action effects available. • A match at the “feed-forward comparator” can only provide a sense of initiation. • Sense of intiation ≠ sense of agency!

  26. Threshold paradigm: Exemplary Trial 90° PD Pointing Direction Visual Feedback 0° Clockwise!

  27. Threshold paradigm: An exemplary trial 90° Visual Feedback PD Pointing Direction 0° counterclowise!

  28. Impairments in perceiving one’s own hand movements correlate with delusions of control

  29. The feeling of agency is gradual

  30. Lindner et al., Curr Biol 2005  Schizophrenia patients with delusions of control are impaired in perceiving the sensory consequences of their actions, i.e. to compensate for self-induced retinal image motion.

  31. No need for a comparator Wegner et al., 2004

  32. The experimental paradigm

  33. Was sind “interne sensorische Vorhersagen”? Das Grundprinzip Ein Beispiel Wolpert and Flanagan, 2001

  34. Interne sensorische Vorhersagen im Kleinhirn? Blakemore et al., 2001 fMRI-Aktivität im Kleinhirn korreliert mit der Verzögerung zwischen Bewegung und selbstinduzierter taktiler Stimulation  Kleinhirn: signalisiert die sensorische Differenz zwischen vorhergesagten und tatsächlichen sensorischen Konsequenzen einer Bewegung

  35. Bedingung 3: Motor Control Trials PD Pointing Direction TF Target Flash a aMotor Error

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