Conscious Intention and Motor Cognition Patrick Haggard, Trends in Cognitive Sciences Vol. 9, No. 6, pp. 290~295 ,2005 2010.08.04 Seung-hyun Lee Soft Computing Lab.

Contents Introduction Thought on intention: Past vs Present Libet’s experiment Action Generation Selection Urge & effect Linking urge to effect Conclusion

A) Intention to move one’s arm Introduction Q) What is left over if I subtract the fact that my arm goes up from the fact that I raise my arm?’ A) Intention to move one’s arm - prior intention - intention in action

Past Thoughts on intention A computational framework for action

Thoughts on intention(cont’d) Past Thoughts on intention(cont’d) Prevalent idea for action: Decartes Mind Action Body

Thoughts on intention(cont’d) Present Thoughts on intention(cont’d) Conscious experiences = consequences of brain activity Why? No direct nor strong tools for studying intention Evasive conscious experience of intending : lack of vivid quality of visual phenomena Changes in dominant view : action as conditioned responses to environmental stimuli

Libet’s Experiment Setup

Libet’s Experiment(Cont’d) Result  Conscious intention is not the cause of action

Libet’s Experiment(Cont’d) Possibilities Conscious intention could be part of an illusion of mental causation, retrospectively inferred to explain behavior Conscious intention could be an immediate consequence of the brain processes which prepare action

Libet’s Experiment(Cont’d) Supporting experiments Lau et al. Used fMRI Judging action vs judging intention Greater activation on pre-supplementary motor area & intra-parietal sulcus for judging intentions Sirigu et al. Patients with focal cerebellar or parietal lesions Parietal group showed delay in the awareness of conscious intention Preparatory activity in the motor areas Action Conscious intention

Action Generation Features Two aspects of will Internal generation Goal-directed. Intention through to the intended effect == Ideomotor Involving a pervasive process of information expansion Two aspects of will Internal generation Ex) reflexes Selection or choice between alternative possible actions

? Action Selection Haggard and Eimer’ s study Selection process Two subject groups: showing early and late judgement of intention Readiness potential  W judgement (X) Lateralised readiness potential  W judgement (O)  Conscious intention is linked to the specific preparation to perform a particular movements Selection process Motor command Conscious intention

Action Selection(cont’d) ? Selection process Unconscious process Studies Ammon & Gandevia : Transcranial Magnetic Stimulation(TMS)  no awareness of altered responding Brasil-Neto et al. : TMS go signal  later responses were unaffected

Conscious Intention Urge Effect(Agency) Definition being about to move Urge & Agency Conscious Intention Urge Effect(Agency) Definition being about to move prediction of the goal state Neuron motoric sensory Focus internal external Corresponding theory Libet's W judgement Jame's ideomotor theory of action

Conscious Intention(Cont’d) Urge Conscious Intention(Cont’d) Fried et al.’s experiment Stimulations of the cerebral cortex via electronodes Result Feeling of an urge to move a specific body part during the low intensity stimulation Real movement under higher stimulation  conscious intentions are at least partly preconstructions rather than reconstructions

Conscious Intention(Cont’d) Sense of Agency Conscious Intention(Cont’d) Reflexive feeling that ‘I’ control events in the outside world Agency as an illusion of mental causation Post-hoc reconstruction of agency People can incorrectly infer agency based on repeated associations between events which are in fact unrelated An experiment by Wegner and Weatley Conscious thought Thought-about event Action Experience that I cause the event

Conscious Intention(Cont’d) Sense of Agency Conscious Intention(Cont’d) Anarchic Hand Syndrome(AHS) by Marcel Patients with frontal lobe and callosal damage Perform well-formed actions in response to environmental cues But actions are contrary to the patient’s will, and occur without preceding conscious intention Della Sala et al’s supporting example Two sources of actions Ownership of action - agency Ownership of the source of action - urge

Conscious Intention(Cont’d) Linking Urge to Agency Conscious Intention(Cont’d) Haggard et al. Experiment: Indicate time of action and effect Result

Conclusion It seems extremely HARD to apply in agent system Studies on imitation People typically imitate other’s goal Not the movements they use to achieve them Bekkering, H. et al., “Imitation of gestures in children is goal directed,” Q. J. Exp. Psychol. A 53, 153–164, 2000 Additional reference(decision making) A. Dijksterhuis, et al., “On Making the Right Choice: The Deliberation-Without-Attention Effect,” Science, vol. 311, no. 5763, pp. 1005-100

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