PSYCH 169: Lecture 1, The problem of consciousness, Qualia, the explanatory gap, 1st/3rd person problem, conjoined twins, concept specific networks

the problem of consciousness

no generally accepted definition of "consciousness"

-the easy problem

-the hard problem

-how objective (physical) brains produce subjective qualia

consciousness

-everyday usage: "awake", "knowing something", "attending to something"

-contrasted with "unconscious"

-often refers to "subjective experience"

Qualia (singular: quale)

qualities that are experienced subjectively

-smell of coffee

-the experience of color

-pitch of a sound

-emphasis on perceptual experience instead of physical/neural mechanisms

quale

what something is like

history of consciousness

the history of explaining a gap

Mary the color scientist

-created by Australian philosopher Frank Jackson

-setting: neuroscience is complete, but has only seen black/white all her life.

-leaves black/white room and sees colors for the first time

-"Wow... I never realized red would look like that"

-"That's red, that's green, nothing new of course..."

Mary the color scientist: Frank Jackson

when Mary comes out, she obviously learns something fundamentally new - what red is like

-now she has color qualia as well as physical facts

Mary the color scientist: Chalmers

no amount of knowledge about physical facts could have prepared her for what it feels like to see a blue sky or green grass

-physical facts about the world are not all there is to know

Mary the color scientist: Objections

Mary does experience something surprising, but its because she comes to know an old fact in a new way

-or, she learned a new skill not a new fact

Mary the color scientist: Daniel Dennett

says Mary will not be surprised:

-premise of the story is false

-we did not follow instructions

-we failed to allow Mary to know everything there is to know about color

Mary the color scientist: Dennett's alternate ending

Mary's captors give her a blue banana

-she is not fooled

-"Hey you tried to trick me. Bananas are yellow, but this one is blue."

-I know everything about color vision

–I know exactly what impressions yellow and blue objects would make on the nervous system

–I know exactly what thoughts they would induce in me

–This is what it means to know all physical facts

Frank Jackson later changed his mind

-Mary will not be surprised by color

-if you think Mary will learn something new, you are biased by your own current limited knowledge

if you think Mary will be surprised:

you believe that qualia (subjective experience) is something additional to knowledge of the physical world

if you think Mary will not be surprised:

you believe that knowing all facts tells you everything, including what it is like to experience something

the explanatory gap

defined as the "gap between physical phenomenon and conscious experience"

-coined by American philosopher Joseph Levine (1984)

-William James (1890): the "chasm between the inner and the outer worlds"

-Tyndall (Irish physicist): "the passage from the physics of the brain to... consciousness"

behaviorists on the explanatory gap

didn't worry about this "great gap" because they simply avoided mentioning consciousness or subjective experience

the easy/hard problems of consciousness

coined by Australian philosopher David Chalmers

the easy problems of consciousness

studied using standard research methods in cognitive science

-attention, memory, motor control

-solved by understanding neural or computational mechanisms

the hard problem of consciousness

subjective experience

-Chalmers: even when you've explained all neural mechanisms and functions related to experience, two questions remain:

-Why are these functions accompanied by experience (why not in a zombie or a robot)?

-How physical processes in the brain give rise to subjective experience?

the first-person third-person problem in the study of consciousness

-scientific study of consciousness based on empirical findings and testable theories

-consciousness is our first-person view of the world

-most science: third-person view, things that can be verified and agreed on by others.

-Is it possible, in principle, to gain access to another person's experience (qualia)

conjoined twins (sharing parts of the brain)

Krista and Tatiana Hogan (British Columbia)

-brains connected by a "thalamic bridge"

-light flashed to eyes of one twin causes activity in visual cortex of other twin

-have same thoughts

-

the first-person third-person problem: neural networks associated with concepts

-Jennifer Aniston Neurons in the Hippocampus

-Halle Berry Neuron

insight into solving the hard problem

conjoined twins and concept specific networks