Main / Freewill Crick
Francis Crick on freewill
Readings
- Francis Crick. 1994. A Postscript on Freewill. In The Astonishing Hypothesis: The Scientific Search for the Soul. Scribner Book Company. HKU intranet
- M.F.S. Rushworth , M.E. Walton , S.W. Kennerley and D.M. Bannerman. 2004. Action sets and decisions in the medial frontal cortex. Trends in Cognitive Sciences, 8:9. doi:10.1016/j.tics.2004.07.009
- Frédéric Assal, Sophie Schwartz, Patrik Vuilleumier (2007) "Moving With or Without Will: Functional Neural Correlates of Alien Hand Syndrome," Annals of Neurology doi:10.1002/ana.21173
Crick's proposals:
- Architecture: computation → many action plans → the chosen plan → action
- We have conscious access to the action plans and the plan that is decided, but not the computations involved in producing the list of plans or in selecting the decided plan.
- We think we have freewill because the decision is unpredictable (perhaps because of chaos).
- We might be able to infer the reasons that go into the computations for the decisions, but we might also confabulate.
Empirical speculations:
- Freewill is located at the brain region known as anterior cingulate sulcus. Arguments:
- This area is damaged in the woman who has "lost her will", with "nothing to say."
- This area receives inputs from higher sensory systems and is located at the higher levels of the motor system. It is connected to the corpus striatum on both sides of the brain.
- This part is also damaged in a patient with the alien hand syndrome (together with damage in the corpus callosum.)
Some News
- June 4, 2004 American Journal of Psychiatry
@The study identified lower brain activity in the anterior cingulate gyrus of compulsive hoarders, compared with other OCD patients.@
- Rushworth et. el. (2004) ACC encodes reinforcement value of action outcomes.
The Alien hand syndrome
http://labnic.unige.ch/nic/papers/FA_SS_PV_AN2007.pdf
@For instance, his left hand could grasp and manipulate parts of clothes or objects, even tear them into pieces, while the patient was seating in his armchair and unaware of these involuntary movements.@
Video: http://www.youtube.com/v/H0uaNn_cl14
- Some old cases
- Need to distinguish between: (a) feeling that the hand does not belong to oneself, and (b) the hand behaving against one's wishes. (doi:10.1007/s10072-003-0149-4)
- Compare with Capgras syndrome
- Two interesting features:
- Triggered opportunistically by nearby objects.
- Increase incidents under fatigue or anxiety (i.e. under reduced attentional control).
- See also doi:10.1016/j.neuropsychologia.2004.06.017
Theory
- Multiple unconscious decision plans.
- Competitive network selects final decision.
- Selection moderated by attention.
Winner-take-all competitive network. White: inhibitory; Black: excitory Follow-up:
- See recent research by Assal et. el. (2007).