Summary second half of lectures
We accept the naturalistic perspective
John Searle: giving examples to understand consciousness
We need conscious behaviour for complex tasks → Kenneth Parks killed his
mother-in-law while sleepwalking → we don’t need consciousness for complex
tasks → are we philosophical zombies (no qualia, whatsitlikeness)
Consciousness has no function → blindsight patients do notice something though
they can’t see it in one visual feld → Young is blindsighted, experiences vision without
consciousness because he does notice something, evolutionary older path → however
not a philosophical zombie (like Lamme thought) because it’s only one side and
he admits he can’t see, zombie would never → blind sighted persons can only do
this in forced-choice experiment, they perform less → zombies would perform just as
well, superblindsight → we need spontaneous behaviour
Evolutionary younger path: eyes to visual cortex (Young lesion)
Evolutionary older bath: processing information without consciousness (this still worked)
Larry Weiskrantz: if you know which part of the brain is damaged if someone has
no consciousness → you know that this part plays an important role when
someone is consciousness
- Naturalism → science
- Natural method (Flanagan) → phenomenology, cognitive scientist and
neurologists (we need both brain and introspection (Penfeld needed both to
discover the homunculus)
- Neodarwinistic theory of evolution → evolutionary perspective, conscious
has to
have evolutionary reasons
- Induction → always problems with generalization, look at several long case
studies
Nagel: phenomenal consciousness = qualia
Flanagan: conscious experiences are homogenous (all have qualia) and
heterogenous (the whatsitlikeness of the experiences is diferent) → problem is
then we need to establish for every experience if it’s consciousness
Biological properties can be adaptive or epiphenomena (secondary phenomena,
byproducts) → they wanted foxes to be more tame, barking and black-and-white-
fur came along with it → pleiotropy, when a certain property can just be a by-
product of something else → some experiences can just be by products, not all
are adaptive
Panadaptionism: tendency to see every trait as adaptive
, Case study 1: Phantom limbs
Identity theorists/materialism think phantom pain is in the brain → dualists in the
mind → so pain might not be in the limb, this is how you can experience phantom
pain → AZ was born without limbs but can feel the pain → Ramanchandran found
representations of her hand on different parts of the skin, not on the hand itself
Explanation moving phantom limbs: the brain still thinks there is a limb that moves, so that’s
why you still feel that it’s there.
Explanation paralyzed phantom limbs: the brain learned that the arm didn’t work anymore,
so it thinks that it’s paralyzed and you don’t feel movement and touch anymore
Motor cortex sends signal to arm and parietal lobe when it has to do something → when
no success signal comes back, this hurts (clenching feeling) → Ramanchandran
used mirrors and a box to help this by opening the existing hand
Case study 2: Synesthesia
Perceiving something with one sense, activates the other → can be tested using
stroop test → conceptual (cortical, meaning) and sensory (limbic, shapes) → all
born as synasthests, defective pruning
Projection hypothesis: phenomenal experiences are projected to parts of your body and
the external world (individuals project their experiences to what normally would cause such
an experience)
Normal cases:
Case study 1: Out of body experiences
No brain activity anymore → dualists say it's between start and end of fat EEG →
materialists say it’s between fainting and coming back to life → Van Lommel tried
to defend the dualists, but was only 1 anekdote he heard, no proof so accept
materialism → can experience this partly when you see someone touching your
back, vision stronger than touch → projection hypothesis
Case study 2: Colour blindness
Naive realism: colours are real, antirealism: colours are secondary properties (just
wavelengths, but thats reductio ad absurdum) → trichromats (three), dichromats
(two, colourblind), tetrachromats (four, more colours) → colours don’t exist, we just
project colours onto things → projection hypothesis
Case study 3: Blind spot
Brain also flls in the space of the blind spot → projection hypothesis
Case study 4: After images
Seeing something red will stimulate the red cones, when after that you look at
something white, the red cones are tired so the other two fre harder, causing
after images → projection hypothesis