Bernard Baars. Excerpts from Conversation on Consciousness (by Susan Blackmore) Consciousness is a real working theatre. Studies Psychology at UCLA

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2 Excerpts from Conversation on Consciousness (by Susan Blackmore) Consciousness is a real working theatre Studies Psychology at UCLA Rejected behaviorism Bernard Baars Psycholinguistics Cognitive Neuroscience Global Workspace Theory

3 The Consciousness Problem Mind-body paradox How can we explain how our mental states are related to our physical states when our bodies are physical and our minds are non-physical? How to ask questions? Pose questions in a way that s answerable Treat 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?

4 William James (1890) and Binocular Rivalry 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 time One image is conscious, the other is unconscious We can now compare the representations Allows us to ask testable questions

5 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?

6 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

7 Consciousness and Object Recognition 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

8 Explanatory Gaps (Problems with this Theory) 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

9 Global Workspace Theory and the Working Theatre 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 metaphor Consciousness is a theatre Spotlight of selective attention Whatever 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

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11 Criticisms for Theatre Analogies 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 FALSE You don t have to have a theatre metaphor with a little self in the audience No coming together in the brain is necessary, the brain has more sophisticated ways of representing information Still a useful analogy

12 The Split Brain and Multiple Consciousnesses 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?

13 This is just a hypothesis! Could be false. 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

14 Multiple Personality Disorder/ Dissociative Personality Disorder One person with multiple personalities/identities Unaware/dissociated from each other Personalities have unique ages/backgrounds/appearances/memories/beliefs/ etc

15 Meditation and the Fourth State of Consiousness According to the Upanishads: four states of consciousness sleeping, dreaming, waking AND pure consciousness Pure consciousness: consciousness without content Bernard 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

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18 Bibliography Excerpts from Conversation on Consciousness, by Susan Blackmore, found in Minds and Brains (Pages ) mos/binocular%20rivalry%20tutorial.pdf e-identity-disorder-multiple-personality-disorder