Excerpts from Conversation on Consciousness (by Susan

Blackmore)

“Consciousness is a real working theatre”

Studies Psychology at UCLA

Rejected behaviorism

Psycholinguistics Cognitive Neuroscience

Global Workspace Theory

Bernard Baars

Mind-body paradox

How can we explain how our mental states are related to our physical states when our bodiesare physical and our minds are non-physical?

How to ask questions?Pose questions in a way that’s answerableTreat Consciousness as a variable “What is the difference between two identical

pieces of knowledge, one of which is conscious, and the other one is unconscious?”

The Consciousness “Problem”

Placed an image of a monkey’s face in the left eye Placed the image of a sunburst in the right eye

Binocular Rivalry!

You cannot see both images at the same timeOne image is conscious, the other is unconsciousWe can now compare the representationsAllows us to ask testable questions

William James (1890) and Binocular Rivalry

“When the eyes are presented with images that are

sufficiently different from each other, an interesting thing happens: Rather than fusing the two images into a combined conscious percept, what transpires is a pattern of perceptual alternations where one image dominates awareness while the other is suppressed; dominance alternates between the two images, typically every few seconds.”

3D Glasses?

“Now we know what the neurons are doing in the visual cortex; we know, apparently, at what point the

neurons seem to recognize conscious events, and unconscious events.”

-Bernard Baars

Brain regions for object recognition = where contents of

consciousness emerge The staircase metaphor

Pathway from eyes to visual cortex Below visual cortex: pathway does not have consciousness The visual cortex is like a staircase

As you “climb the staircase” you add more analysis of the visual information

Object recognition is the top of the staircase at the end of the lower temporal cortex

Consciousness occurs at the top of this staircase

Consciousness and Object Recognition

How is it that neurons firing in one part of the brain

cause consciousness, while similar neurons firing in a similar way in another area of the brain doesn’t?

Still lots of gaps in our understanding (still in a primitive stage)

We know a number of basic phenomena

We have useful analogies but they still need to be improved

Explanatory Gaps(Problems with this Theory)

The "inner domain in which we can rehearse telephone numbers to

ourselves [...]. It is usually thought to include inner speech and visual imagery." (in Baars, 1997).

The theatre metaphorConsciousness is a theatre Spotlight of selective attentionWhatever is in the spotlight is the contents of

consciousness In the dark areas of the theatre are the director, stage

hands, etc.These shape what happens in the spotlight but aren’t

apparent themselves

Global Workspace Theory and the “Working Theatre”

Dan Dennett (in Consciousness Explained) : most people

believe there is a place in the brain where “everything comes together” and creates consciousness.

When this “coming together” occurs, events become conscious/apparent to a “viewer” (YOU!)

This theory is tempting, but FALSEYou don’t have to have a theatre metaphor with a little

self in the audienceNo “coming together” in the brain is necessary, the

brain has more sophisticated ways of representing information

Still a useful analogy

Criticisms for Theatre Analogies

Roger Sperry and Michael Gazzaniga Split brain: a brain where the corpus callosum connecting

the two hemispheres of the brain is severed (The two hemispheres cannot communicate)

In the study: both hemispheres were able to answer questions, report perceptual experiences unique to that hemisphere, control the opposite side of the body

Both hemispheres meet criteria for consciousness…

Multiple Consciousnesses?

The Split Brain and Multiple Consciousnesses

• So do we all have multiple consciousnesses?

• Billions of signals pass between the two hemispheres in a normal brain

• Edelman’s dynamic core hypothesis: these signals cause the areas on either side of the brain to work together

• So no… no multiple consciousnesses

This is just a hypothesis! Could be false.

One person with multiple personalities/identities

Unaware/dissociated from each other

Personalities have unique ages/backgrounds/appearances/memories/beliefs/etc…

Multiple Personality Disorder/ Dissociative Personality Disorder

According to the Upanishads: four states of consciousness sleeping, dreaming, waking AND “pure consciousness”

Pure consciousness: consciousness without contentBernard suggests an experiment to find pure consciousness Have subjects listen to noisy air conditioner and report gaps in

the experience of external sound while meditating Dilemma: Gaps may be attributed to falling asleep Having subjects wear a EEG cap would show definitively if they

were falling asleep and would solve this dilemma Dilemma: People may report falsely Testers could use artificial gaps in the noise to solve this dilemma

Meditation and the Fourth State of Consiousness

Excerpts from Conversation on Consciousness, by Susan

Blackmore, found in Minds and Brains (Pages 211-223) http://visionlab.harvard.edu/Members/Olivia/tutorialsDe

mos/Binocular%20Rivalry%20Tutorial.pdf http://www.3dglassesonline.com/learn/how-do-3d-

glasses-work http://www.swamij.com/levelsdimensions.htm http://www.scholarpedia.org/article/Binocular_rivalry https://www.psychologytoday.com/conditions/dissociativ

e-identity-disorder-multiple-personality-disorder

Bibliography