23.+Consciousness

May 12, 2015
 * 23. Consciousness**

Where does consciousness come from? Altered states of consciousness Animal consciousness?
 * Outline**


 * Where does consciousness come from?**

Neurons are individuals following simple rules. Together, they create an organized whole. Brains are conscious.
 * Bees do the same thing, so are beehives conscious?

Neuronal Workspace Hypothesis
 * The brain is made up of specialized areas
 * "Workspace neurons" link these areas
 * Hypothesis: Stimuli become conscious when linked to each other via the workspace
 * The workspace allows:
 * Flexibility
 * Adjusting the processing in one system in light of what is going on elsewhere
 * Working memory
 * Working memory can contain various representations: abstract concepts, images, words...
 * Workspace neurons connect to all of these
 * Attention
 * Consciousness = attention?
 * Evidence:
 * During non-REM sleep, modules are active but they aren't communicating. So no consciousness, and no dreams.

Split brain
 * Altered states of consciousness**
 * Normally there are two cerebral hemispheres connected by the corpus callosum
 * Patient with a severed corpus callosum:
 * He can simultaneously draw different shapes with each hand, as if they're controlled by different brains
 * When a word is flashed to one side of the brain
 * Word flashed to his right (goes to his left brain), he can report it
 * Word flashed to his left (goes to right brain), he can't say it, but he can draw it
 * Sees two words: Toad + stool
 * Toad goes to nonspeaking right brain, stool goes to speaking left brain
 * First he draws a toad with his right hand. After he says stool out loud, his right hand draws a stool.
 * Confabulation - fabricating explanations for one's behavior
 * []

Vegetative states
 * Naci et al. (2014): Participants watched an eight minute episode where a 5 year old walks around with a partially loaded revolver, shooting at people and saying "bang"
 * Suspense makes normal people's brains go crazy
 * Behaviorally unresponsive patient showed activity in sensory areas only
 * Another, who had been in a "vegetative state" for 16 years, showed brain activity in sensory and executive brain areas. Indistinguishable from normal participants.
 * Owen et al. (2006) - using fMRI - when a patient in a vegetative state was asked to imagine playing tennis or moving around her home, she activated predicted cortical areas in a manner indistinguishable from that of healthy volunteers
 * Summary
 * People in vegetative states can:
 * Understand instructions
 * Engage in mental imagery
 * Appreciate suspense in a film
 * Up to 1 in 5 patients in vegetative state seem to be conscious

Anesthesia
 * Alkire et al. (2008)
 * Paralytic effects of drugs used during surgery were blocked from one forearm
 * Patients under general anesthesia can sometimes carry on conversation using hand signals
 * Postoperatively, the deny ever being awake. Thus, retrospective oblivion is no proof of unconsciousness


 * Langsjo et al. (2012)
 * Participants were under anesthesia
 * They opened their eyes on command when the higher parts of the brain were not yet "turned on"
 * Consciousness may arise (or begin to) in subcortical regions
 * Summary
 * When we are under anesthesia, we:
 * Can respond to instructions
 * Can have a simple conversation
 * Don't remember it later
 * Is it really consciousness, or is it like blindsight--responding without awareness?

Drinking
 * Assefi & Garry (2003)
 * Subjects drank plain tonic water
 * Half were told it was a vodka and tonic
 * Half were told it was just tonic
 * Took part in an eyewitness memory experiment
 * "Alcohol" group were
 * More swayed by misleading post-event information
 * More confident about the accuracy of their responses
 * Believing they had been drinking affected participants' memories
 * It also affected their social behavior
 * Thinking you've been drinking makes you drunk
 * This is an example of the placebo effect - a biologically inert treatment that has beneficial effect due to a patient's belief in the treatment

Placebo Effects
 * Placebos doesn't just affect behavior. They affect health!
 * Placebos reduce activity in brain areas associated with pain
 * Stronger placebos work better
 * Works better:
 * Big inert pills
 * 4 pills a day
 * Colored pills
 * Expensive pills
 * Works worse:
 * Small inert pills
 * 2 pills a day
 * White pills
 * Discount pills
 * Inert pills work...
 * Saline injections work better...
 * Sham surgery works even better.
 * Summary
 * Conscious expectations have meaningful effects on very low level, non-conscious health outcomes. Conscious experience is powerful!

Blindsight
 * People with blindsight:
 * Behave in ways that show they can see at least a little bit
 * Example: If a blindsight patient walks down a hall filled with objects, he picks his way around the objects
 * Consciously experience the world as if they're blind
 * Primary visual cortex doesn't work in blindsight patient
 * Necessary for conscious awareness of visual information
 * Auxiliary visual pathway works in blindsight patient

Cowey and Stoerig (1995) - tested monkeys who'd had surgery so that they had blindsight in the right visual field. They were shown a yellow dot in their right visual field.
 * Animal Consciousness**
 * Forced response trials
 * They can see the yellow dot
 * "Opt-out" trials
 * They report that they can't see the yellow dot
 * They seem to experience blindsight
 * Suggests monkeys distinguish between conscious and unconscious experiences--in the same way we do

Nisbett and Wilson (1977)
 * Products: The thoughts that we experience consciously
 * What we "see"
 * Processes: The cognitive functions that underlie the products (and everything else)
 * Perceptions that (could) feed into consciousness