The Mind-Body Problem and the Puzzle of Consciousness Minds and Machines

The Mind-Body Problem and the Puzzle of Consciousness

Minds and Machines

What is the Mind-Body Connection?

• Our body and mind seem to be intimately connected:– When I hit your foot with hammer, you will

feel pain.– When you decide to raise your hand, you do

it• But what exactly is this connection

between our body and mind? Why is there such a connection? How does it work?

Obvious Answer: The Brain!

• The brain is part of the body, and the brain is responsible for the mind

• … OK, but what do you mean by ‘responsible’?

• What exactly is the mind-brain connection?!

Descartes’ Argument

– I am certain that my mind exists

– I am not certain that my body exists • (or any part thereof (incl. brain), or anything else physical)

– Therefore, my mind is not the same as my body • (or any part thereof (incl. brain) , or anything else physical)

Idealism

• Idealism: the mind is all that exists– the ‘physical world’ we perceive to be

around us is just a construction of our mind.

• Solipsism: only my own mind exists!

Dualism

• Both Mind and Body exist, but they are completely distinct!– Body is physical– Mind is non-physical

Cartesian (Interactive) Dualism

• Mind and Body exist, but are distinct• Mind and Body causally interact

(through the brain)

But What About the Brain?

• The brain seems to be more than a ‘mere’ communication device.

• In fact, it seems to regulate a lot of behavior, simply by it being ‘wired up’ the way that it is, connecting sensory input with motor output.

• So what is this ‘extra’ mind for?!

Descartes: ‘Automatons’ vs ‘Deliberators’

• Descartes responded that it is true that the brain by itself can account for a lot of behavior.

• However, he suggested that there was a fundamental difference between humans and animals:– Animals are mere ‘automatons’: their brain allows them to

behave in ways advantageous to them, but since they do not have a mind, they can never get away from their purely ‘mechanical’ behavior.

– Humans, on the other hand, do have a mind. So they can perform deliberative reasoning and decision-making, be creative and do new things.

Intuitive Argument for Dualism

• Also, there is an even more straightforward argument for Dualism:

• Physical stuff is ‘tangible’:– It takes up space– It has mass– It can be touched, kicked, painted, observed, etc.

• Our mind is not like that at all!

Classical Dualism

• Oldest form of dualism• Mind and body exist but are distinct

– Mind can survive bodily death• The mind controls the body

– Without the mind, the body would do nothing– Animism

Materialism

• The mind is part of a purely physical universe.– No ‘non-physical mind-stuff’– ‘Mind’ is an abstraction … describing our cognitive

capabilities such a perception, reasoning, decision-making … which we have due to our brain!

– ‘mind is what brain does’– No brain -> no mind! No ghosts, no souls, no

spirits.

Materialism vs Dualism:Science vs Religion?

• Materialists and Dualists have been fighting hard.

• During this fight, I often hear the following argument:– “Dualism is old and unscientific. In fact, most dualists are religious

people who still believe in souls and spirits. Materialism is modern and scientific, and is free from any religious thinking. Therefore, dualism is false and materialism is true.”

• Please don’t do this!! You’re not making any arguments that delve into the issue, but instead you are making cheap ad hominems and circumstantial reasoning. Do not frame this debate as a “religion vs science” fight!

The Puzzle of Consciousness… in Pictures!

Our Eyes as a Window to the World

What is Really out there?

?

I see a tree

What do You See?

?

I see a tree

Invertoids

?

I see a tree

Who Is the Invertoid? …

?

I see a tree

Weirdoids

I see a tree

Science:‘Publicly Observable’

1 tree31,437 leavesE = mc2

etc.

!

Zombies

?

I see a tree

The Zombie Paradox

I have a conscious experience of seeing a tree

BlindsightI don’t have any conscious experience, but I think there is a tree

Blindsight Video

Materialist Theories of Consciousness

• Consciousness is:– quantum collapses in microtubules internal to neurons (Penrose,

Hameroff)– thalamically modulated patterns of cortical activation (Llinas)– left hemisphere based interpretative processes (Gazzaniga)– emotive somatosensory hemostatic processes based in the frontal-

limbic nexus (Damasio) – synchronous neural oscillations at 40-70Hz in the claustrum (Crick,

Koch)– spatiotemporal patterns in electro-magnetic field produced by the

brain (McFadden, Pockett)– global workspace of cognitive activity (Baars)– integrated information (Tononi)

“Consciousness is a fascinating but elusive phenomenon; it is impossible to specify what it is, what it does, or why it evolved. Nothing worth reading has been written on it.”

– Stuart Sutherland, International Dictionary of Psychology

Epiphenomenalism

• The puzzle of consciousness lead to another form of Dualism: Epiphenomenalism

• Epiphenomenalists state that the mind is the result of (i.e. caused by) physical processes, but that it is causally inert itself.

• Our conscious thoughts, experiences, and feelings are like the ‘sparks’ produced by a running ‘machine’ (the brain): they are produced by the machine, but have no effect on the functioning of the machine.

Non-Interactionist Dualism

• How can something non-physical interact with something physical?!?

• E.g On Descartes’ view, how does the brain communicate with the mind?

• Thus, some Dualists not only proposed that the mind and body are completely distinct, but that they don’t even interact!

Positions on the Mind-Body Problem

Monism Dualism

Materialism IdealismNon-InteractionistDualism

InteractionistDualism

ClassicalDualism

CartesianDualism

Epiphenomenalism

: causal relationship

Quiz Question 1

• “Without a mind, physical entities wouldn’t do anything by themselves. A mind is like a ‘captain of the ship’ or ‘ghost in the machine’ that controls the behavior of the physical entity it inhabits.”. This is a description of:

• A. Classical Dualism• B. Cartesian Dualism• C. Non-Interactive Dualism• D. Epiphenomenalism

Quiz Question 2

• “The proponents of dualism are probably the same people who deny evolution, and everything else science. Therefore, dualism is false.”

• Is this a good argument?• A. Yes• B. No

Quiz Question 3• The Zombie Argument is:• “According to Materialism, consciousness has a purely physical

basis. This means that it is impossible to have that physical basis without being conscious. However, we can conceive of zombies, which are beings that are physically identical to us, but that aren’t conscious. Therefore, Materialism must be false.”

• “The Problem of Other Minds states that you don’t know if someone other than yourself is conscious. However, if we wouldn’t be conscious, then we would be like zombies. Since we can see that no one behaves like a zombie, we know that other people in fact are conscious. So there is no Problem of Other Minds.”