Is All Thinking Unconscious?

1. Is All Thinking Unconscious?

2. Benjamin Libet • Neuroscientist at • University of California • Died July 2007, age 91 • Two important sets of experiments in 1970s on consciousness of sensations and consciousness of decisions to act • Controversial experiments, supporting theories of“unconscious thinking”, e.g. by Jackendoff and Wegner.

3. Libet’s Experiments Set One: Backward Referral of Sensations Setup: • Performed on patients undergoing open brain surgery • Libet stimulated their brains and their hands with electrodes, while timing their verbal responses and monitoring their brain activity

4. Results: • Consciousness of sensations lags behind the stimuli by about half a second (500 ms) • But the timing of consciousness of the sensations is referred backward to the time of the stimulus Conclusion: Fast movements, such as in playing tennis or playing video games, must be implemented unconsciously, and become conscious only about half a second afterwards.

5. Set Two: Unconscious Initiation of Voluntary Actions Setup: Subjects fitted with electrodes on their scalps attached to an electroencephalogram (EEG) to measure their brain activity. An oscilloscope was set up -- a specially designed clock with a spot of light revolving around the face approximately 25 times per second.

6. Subjects then asked to make small movements with their hands, e.g. flick their wrists, spontaneously, “when they feel the urge” (in other words, to make a small, voluntary movement of their own free will) At the same time, subjects were instructed to watch the oscilloscope and report the exact position of the revolving circle at the moment when they first decide to flick their wrists (in other words, to record the exact timing of their free decision).

7. Results: • Subjects reported deciding to make a movement approximately 200 milliseconds (ms) prior to actual movements. • However, the EEG recorded electrical charges in the brain building up to the time of the movements, which started around 500 ms (up to 2000 ms) before the movement. He called these electrical charges “readiness potentials” (RPs). • In other words, the brain apparently began preparing for a movement 300 ms before subjects had the conscious impulse to move.

8. Conclusion: • Conscious decisions are preceded by unconscious processes in the brain by about a third of a second. • In other words, decisions are not made consciously. Decisions are made unconsciously and then become conscious. • Conscious initiation of decisions in an illusion. Note: • Libet’s results and interpretation of data are very controversial, because of the difficulty of timing intentions.

9. But: • Libet’s results are replicable: other people have had the same results. • Libet’s results support Jackendoff’s and Wegner’s theories (discussed below). fMRI: • Chun Siong Soon, Marcel Brass, Hans-Jochen Heinze, John-Dylan Haynes: “Unconscious determinants of free decisions in the human brain”.http://www.nature.com/neuro/journal/v11/n5/abs/nn.2112.html

10. Jackendoff’s Theory Ray Jackendoff Cognitive Scientist Tufts University (with Daniel Dennett) Intermediate Level Theory of Mental Representation Consciousness and the Computational Mind (1987)See also: http://books.google.com/books?id=XgHFPVhaeVEC Thinking is an unconscious process.

11. Three levels of mental representations • The external level Specialized modules of perception (vision, hearing, taste, etc.), proprioceptive system (perception of body states)and motor system Informationally encapsulated and inaccessible to consciousness Only the results of perceptual faculties become available to consciousness

12. 2) The internal level • The inner core • The location of thought and understanding • Operates through the manipulation of non-imagistic conceptual structures, i.e. symbols with semantic content (via mentalese) • Where syntax is processed, spatial relationshipsare understood, and music is understood • Completely inaccessible to awareness

13. 3) The intermediate level The only level that is conscious. Images received from perceptual modules, or memory or translated from thoughts generated in the inner core. Images include visual images, auditory images (primarily words), and sensory images (e.g. tastes, smells, bodily sensations). These images are the only mental representations available to consciousness. Consciousness consists only of images of thoughts. Images of thoughts are distinct from thoughts themselves.

14. The Intermediate-Level Theory of Mental Representations

15. Summary of Jackendoff’s Theory Thoughts are formed unconsciously. After they are formed unconsciously, they are translated into imagery, i.e. a thought is formed in mentalese, then translated in natural language and the phonetic form of the thought (the sound of the words) is projected into consciousness. We become aware of our thoughts only in phonetic form(or visual form, etc.), and only after this sound image(or visual image, etc.) is projected into consciousness. You can become aware of your thoughts in the form of words, or pictures, or even smells, sensations, etc., but you cannot become aware of your thoughts in their original non-imagistic form.

16. Why does Jackendoff believe this? Thoughts are unconscious, then translated to imagery. We cannot be aware of anything except mental images. But, images of thoughts = thoughts Evidence for mentalese: • Ambiguity in imagery (verbal, pictorial) = ambiguity of meaning • Tip-of-the-tongue phenomenon • Translatability of propositions • Similarities among natural languages

17. Reasons continued Introspective evidence: thoughts pop into your head. You cannot catch yourself thinking, deciding, etc. How do you decide? • You are aware of options. • You are aware of reasons. • You make an unconscious calculation. • You are aware of decision. You cannot introspect the unconscious calculation. You are only aware of the effect of the calculation(i.e. you are aware of the thought after it occurs).

18. Wegner’s Illusion of Conscious Will Daniel Wegner Psychologist The Illusion of Conscious Will (2002) “The mind’s best trick: how we experience conscious will” (2003) Conscious will is an illusion.

19. Illusions of conscious will Three ways in which the experience of conscious willcan be wrong: • Someone thinks they have not caused an action that they actually have caused. • Someone thinks they have caused an action that they actually haven’t caused. These two show double dissociation: the feeling of having willed an action can be doubly dissociated from actually having caused an action. 3) Confabulation: someone is mistaken about how they have caused an action

20. Someone thinks they have not caused an action that they actually have caused (illusion of non-control) • Many examples: • Delusion of alien control: • - a type of schizophrenia • - patients think that an alien, God, devil or the FBI is • controlling their actions • Dissociative Identity Disorder • - also called “Multiple Personality Disorder” • - actions are attributed to another personality occupying • the same brain

21. Alien hand syndrome • sometimes occurs in split-brain patients (Split-brain patients have had the corpus collosum connecting the left and right hemisphere of their brain cut – drastically reducing communication between the two hemispheres) • also occurs in non-split brain patients • patient has no control over one hand • “alien” hand can conduct complex voluntary actions, such as unbuttoning a shirt, moving a chess piece, grabbing a cigarette or trying to strangle the patient

22. Automatisms • Complex voluntary actions produced with no sense of will and attributed to spirits or other strange forces • E.g. • Spirit possession • Dowsing • Table turning • Ouija board writing

23. Grailog for 1): P believes that P has not caused an action A, and P has caused the action A. cause believe A P P cause negation

24. Someone thinks they have caused an action that they actually haven’t caused (illusion of control) I-Spy study Participants were set up at a computer looking at a picture of many random objects and sharing a mouse with a confederate Meanwhile, they heard words over a headphone. When they heard a certain word (e.g. swan), the confederate gently forced them to stop on a picture of that object (e.g. swan) When asked, participants often said they chose to stop at the swan. When not forced, participants did not generally stop at the object they heard over the headphones Conclusion: participants thought they had willed an action that they had not.

25. Grailog for 2): P believes that P has caused an action A, and P has not caused the action A. cause believe A P P cause negation

26. 3) Confabulation: Confabulation occurs when people are wrong about why they performed an action. They come up with a reason for acting, but they do not know the true reason of their action. e.g. I hypnotize you to stand up at 3:00. At 3:00 you stand up. I ask you why you stood up. You say, you needed to stretch your legs. Shows that people are not aware of their true reasons for acting, but still feel that they are acting freely for rational reasons(cf. rationalization). Occurs in cases of hypnosis and direct brain stimulation, and in split brain patients. Maybe occurs in normal people all the time.

27. Grailog for 3): P believes that P has caused an action A, and P has caused the action A. P believes that P’s causation of A has reason X, and P’s causation of A has different reason Y. cause unequal believe A P P cause believe reason reason X Y

28. Is Conscious Will Generally an Illusion? These cases show that we are often wrong when we think that our conscious thought has caused an action. We may always be wrong. Two possibilities: • The experience of conscious will is unreliable. We normally consciously will our actions, and our feeling of having willed an action is generally correct, but sometimes the feeling of conscious will is an illusion. 2) The theory of apparent mental causation The experience of conscious will is always an illusion.Conscious thoughts do not cause actions.

29. Wegner makes a spectrum of claims: From The mind’s best trick: how we experience conscious will: • “Does this mean that conscious thought does not cause action? It does not mean this at all …The point made here is that the mind’s own system for computing these relations provides the person with an experience of conscious will that is no more than a rough-and-ready guide to such causation…” (Wegner 2003). From The Illusion of Conscious Will: • “The fact is, it seems to each of us that we have conscious will. It seems we have selves. It seems we have minds. It seems we are agents … it is sobering and ultimately accurate to call all this an illusion” (Wegner 2002). • “All feeling of doing is an illusion” (Wegner 2002).

30. Conscious Will is always an illusion Wegner’s boldest claim. Actions usually follow conscious thoughts. Hence we conclude the thoughts cause the actions. We think, “I’ll have a piece of candy”, then we eat a piece of candy. But the causal relation is an illusion. Common fallacy: “post hoc propter hoc” -- if A follows B, B caused A. Also possible: A and B have a common cause.

31. The Theory of Apparent Mental Causation Unconscious thought produces conscious thought. Unconscious thought produces action. Conscious thoughts and actions have common cause: unconscious mental processes. Unconscious processes also produce the feeling of having consciously willed an action. Conscious willing of actions is an illusion.

32. How the illusion is generated

33. Readings for next week Focus: Libet, Benjamin (1999) “Do we have free will?”, Journal of Consciousness Studies, Volume 6, Numbers 8-9, pp. 47-57(11). http://pacherie.free.fr/COURS/MSC/Libet-JCS1999.pdf Extra: Velmans, Max (2002) “Preconscious free will”, Journal of Consciousness Studies 10, 42-61. http://cogprints.org/3382/1/Cogprints_PRECONSCIOUS_FREE_WILL.htm Searle, John (2000), “Consciousness, Free Action and the Brain”, Journal of Consciousness Studies 7, Vol. 10, No. 10 (October)Abstract: http://www.imprint.co.uk/jcs_7_10.html#John