Is All Thinking Unconscious (SLIDES)

7/30/2019 Is All Thinking Unconscious (SLIDES)

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Is All Thinking Unconscious?


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Libets Experiments

Set One:

Backward Referral of Sensations

Setup:

Performed on patients undergoing open brain surgery

Libet stimulated their brains and their hands withelectrodes, while timing their verbal responses andmonitoring their brain activity


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Results:

Consciousness of sensations lags behind the stimuli byabout half a second (500 ms)

But the timing of consciousness of thesensations is referred backward to thetime of the stimulus

Conclusion:

Fast movements, such as in playing tennisor playing video games, must be implementedunconsciously, and become conscious onlyabout half a second afterwards.


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Set Two: Unconscious Initiation of VoluntaryActions

Setup:

Subjects fitted with electrodes on theirscalps attached to an

electroencephalogram (EEG) tomeasure their brain activity.

An oscilloscope was set up -- a speciallydesigned clock with a spot of lightrevolving around the face approximately25 times per second.


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Subjects then asked to make small movements with theirhands, e.g. flick their wrists, spontaneously, when they feelthe urge (in other words, to make a small, voluntarymovement of their own free will)

At the same time, subjects wereinstructed to watch the oscilloscope

and report the exact position of therevolving circle at the moment whenthey first decide to flick their wrists(in other words, to record the exact

timing of their free decision).


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Results:

Subjects reported deciding to make a movement approximately 200milliseconds (ms) prior to actual movements.

However, the EEG recorded electrical charges in the brain building up tothe time of the movements, which started around 500 ms (up to 2000 ms)before the movement. He called these electrical charges readinesspotentials (RPs).

In other words, the brain apparently began preparing for a movement 300ms before subjects had the conscious impulse to move.


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Conclusion:

Conscious decisions are preceded byunconscious processes in the brain by about athird of a second.

In other words, decisions are not madeconsciously. Decisions are made unconsciouslyand then become conscious.

Conscious initiation of decisions in an illusion.

Note:

Libets results and interpretation of data are verycontroversial, because of the difficulty of timing

intentions.


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But:

Libets results are replicable: other people havehad the same results.

Libets results support Jackendoffs and Wegnerstheories (discussed below).

fMRI:

Chun Siong Soon, Marcel Brass, Hans-JochenHeinze, John-Dylan Haynes: Unconsciousdeterminants of free decisions in the human brain.http://www.nature.com/neuro/journal/v11/n5/abs/nn.2112.html


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Jackendoffs TheoryRay 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.


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Three levels of mental representations

1) The external level

Specialized modules of perception (vision, hearing, taste, etc.),proprioceptive system (perception of body states)

and motor system

Informationally encapsulated and inaccessible toconsciousness

Only the results of perceptual faculties become available toconsciousness


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2) The internal level

The inner core

The location of thought and understanding

Operates through the manipulation of non-imagisticconceptual structures, i.e. symbols with semantic content(via mentalese)

Where syntax is processed, spatial relationships

are understood, and music is understood

Completely inaccessible to awareness


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3) The intermediate level

The only level that is conscious.

Images received from perceptual modules, or memory ortranslated from thoughts generated in the inner core.

Images include visual images, auditory images (primarilywords), and sensory images (e.g. tastes, smells, bodily

sensations).

These images are the only mental representationsavailable to consciousness.

Consciousness consists only of images of thoughts.

Images of thoughts are distinct from thoughts themselves.


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The

Intermediate-Level

Theory of Mental

Representations


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Thoughts are formed unconsciously.

After they are formed unconsciously, they are translatedinto imagery, i.e. a thought is formed in mentalese, thentranslated in natural language and the phonetic form ofthe thought (the sound of the words) is projected intoconsciousness.

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 ofwords, or pictures, or even smells, sensations, etc., butyou cannot become aware of your thoughts in theiroriginal non-imagistic form.

Summary of Jackendoffs Theory


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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


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Reasons continued

Introspective evidence: thoughts pop into your head. Youcannot 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).


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Wegners Illusion of Conscious Will

Daniel Wegner

Psychologist

The Illusion of Conscious Will (2002)

The minds best trick: how we experienceconscious will (2003)

Conscious will is an illusion.


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Illusions of conscious will

Three ways in which the experience of conscious willcan be wrong:

1) Someone thinks they have not caused an action thatthey actually have caused.

2) Someone thinks they have caused an action that theyactually havent caused.

These two show double dissociation: the feeling of havingwilled an action can be doubly dissociated fromactually having caused an action.

3) Confabulation: someone is mistaken about how theyhave caused an action


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1) 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 occupyingthe same brain


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Alien hand syndrome

sometimes occurs in split-brain patients

(Split-brain patients have had the corpus collosumconnecting the left and right hemisphere of their braincut drastically reducing communication between thetwo 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


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Automatisms

Complex voluntary actions produced with no sense ofwill and attributed to spirits or other strange forces

E.g.

Spirit possession

Dowsing

Table turning

Ouija board writing


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PAbelieve

causeP

cause

Grailog for 1):

P believes that P has not caused an action A,and P has caused the action A.

negation


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2) Someone thinks they have caused an

action that they actually havent caused(illusion of control)

I-Spy study

Participants were set up at a computer lookingat a picture of many random objects and sharinga mouse with a confederate

Meanwhile, they heard words over a headphone.

When they heard a certain word (e.g. swan), the confederate gently forcedthem 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 heardover the headphones

Conclusion: participants thought they had willed an action that they had not.


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PAbelieve

causeP

cause

Grailog for 2):

P believes that P has caused an action A,and P has not caused the action A.

negation


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3) Confabulation:

Confabulation occurs when people are wrong about why theyperformed an action.

They come up with a reason for acting, but they do not know thetrue reason of their action.

e.g. I hypnotize you to stand up at 3:00. At 3:00 you stand up. I askyou 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 insplit brain patients.

Maybe occurs in normal people all the time.


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PA

causeP

cause

Grailog for 3):

P believes that P has caused an action A,and P has caused the action A.P believes that Ps causation of A has reason X,

and Ps causation of A has different reason Y.

believe

X

believe reason

Y

reason

unequal


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Wegner makes a spectrum of claims:

From The minds best trick: how we experience conscious will:

Does this mean that conscious thought does not cause action? Itdoes not mean this at all The point made here is that the minds

own system for computing these relations provides the person withan 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 areagents it is sobering and ultimately accurate to call all this anillusion (Wegner 2002).

All feeling of doing is an illusion (Wegner 2002).


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Conscious Will is always an illusion

Wegners boldest claim.

Actions usually follow conscious thoughts. Hence we conclude thethoughts cause the actions.

We think, Ill 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.


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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 havingconsciously willed an action.

Conscious willing of actions is an illusion.


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How the illusion is generated


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Readings for next week

Focus:

Libet, Benjamin (1999) Do we have free will?, Journal ofConsciousness 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 ofConsciousness Studies 10, 42-61.http://cogprints.org/3382/1/Cogprints_PRECONSCIOUS_FREE_WILL.htm

Searle, John (2000), Consciousness, Free Action and the Brain, Journal ofConsciousness Studies 7, Vol. 10, No. 10 (October)Abstract: http://www.imprint.co.uk/jcs_7_10.html#John

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