Intro. to the Mind Notes,
Week 2: Methods for Studying the Mind (HMW, Ch. 1)
A. Why Understanding the Mind is Difficult
"A wise man marvels at the commonplace"
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What the mind does is hard. (Dismantling the Myth of Simplicity)
a. Vision
i. The input is an array of neuron activation strengths. The
project is to convert that into a mental model of the 3D world.
ii. This is extremely difficult, in fact impossible without added
information.
iii. Doing so requires systems for: detecting object boundaries,
color, shape, etc. that depend on facts about the nature of objects that
people will encounter. (Objects do not change shape, or vary their color
as they move, etc..)
b. Movement
i. Two legged running over complex terrain is far beyond what
the best robots can manage.
ii. Controlling arms and hands is extremely complex. Consider
how adjustments for weight depend on the geometry of the situation. NASA's
arm has only a few joints, but the software was a major project.
c. Concepts and Reasoning
i. Is it so clear you know what a bachelor is? p.13
ii. Reasoning we take to be simple is extremely complex. See
p.
14 on quart of blood. Also see the story of R2D1. p. 14
d. Plans, Goals Motives require sophisticated programs. Being evil or good
require lots of code.
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What the Mind does is varied. (Dismantling the Myth of Unitary Intelligence)
a. There is no single wonder principle that explains intelligence.
b. Intelligence is composed of a multitude of different skills and
talents that interlock
c. We find evidence for this in dissociations:
i. Change in scene but no feeling of motion.
ii. Recognize objects but no faces, or faces but not the person!
d. Even vision is broken up into many separate skills processed in different
areas of cortex: color, motion, shape, etc..
B. Methods for Understanding the Mind
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Pinker claims that understanding the mind means reverse engineering the
brain.
a. This means treating the brain as if it were a machine that does
a job, and figuring out how its parts function together.
b. The process is analogous to taking a watch and figuring out what
makes it tick and keep time.
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There are a number of assumptions that guide this quest.
a. Functionalist Assumption: The Mind is the function(ing) of the Brain.
"The mind is what the brain does." (Think of Aristotle: The Soul is the
Form of an animal, that is, the principle behind what it does.)
b. Computational Assumption: What the brain does is process information.
So what matters to Cognitive Science is not the matter (neurons, silicon
chips) but the nature of the processing.
c. Modularity Assumption: The brain is composed of a variety of different
modules with special purpose functions. There is no one "organ of intelligence".
d. Genetic Assumption: The brain/mind is a genetic product ...
e. Evolutionary Assumption: of natural selection for the life of a
hunter gatherer.
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Pinker feels that the last two assumptions have been sadly ignored by the
social sciences
C. The Computational Assumption (AI, Robotics and Computational Linguistics)
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The Computational Assumption can help answer a set of puzzles:
a. The Metaphysical Problem: What is a mind?
b. The Interaction Problem: How can the mind cause and be caused
by the natural world? For example, how can a turned ankle (natural) cause
pain (mental) and a plan (mental) to call my wife to pick me up which causes
my hand to push buttons on my cell-phone? It would seem that pains and
plans are colorless, odorless, tasteless and not accessible to science.
c. The Homunculus Problem: How can we explain perception without
assuming the existence of a little person inside who receives the perception?
d. The Problem of Intentionality: How can states in the brain
be about the world - how can they have meaning?
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On the Computational view, the mind just is information processing performed
by the brain, and no more mysterious than information processing found
in a computer. In both cases there is no need for a non-natural "soul"
to explain the behavior we find. Furthermore information processing is
carried out according to the causal principles of the natural world, so
there is no mystery as to why mental states can cause and be caused by
natural states.
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On the Computational story, mental states and events are just very complicated
physical states or events which process information about the world.
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But the information processing account does not say that the brain is like
a computer in its speed, number of circuits, or its serial style of processing.
That takes the analogy with computers too literally. The view says that
the implementation details concerning the actual mechanisms used by the
brain (neurons and synapses) are irrelevant; the mind could be implemented
just as well in silicon or chemicals unknown to man. So what matters for
the existence of a mind is not the matter or material, but the form that
material takes on: an ability to pass through a complex set of information
rich states, i.e. to process information. So presumably computers, and
silicon based alien life forms can have minds also.
D. The Modularity Assumption (Neuroscience and Neuropsychology)
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The mind is composed of many different information processing modules,
each one specialized for a specific function.
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The job of cognitive science is to reverse engineer each one. This means
we must ...
a. Figure out what the modules are, and what they do, using studies
in neurosciences: neuroanatomy, neuropsychology, and our common sense.
b. Invent information processing mechanisms that could do what a module
does and then verify that those mechanisms are used by the brain.
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Vision is an example of this.
E. The Genetic/Evolutionary Assumption (Biology and Evolutionary Psychology)
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On this assumption minds are genetic products, for the brain and what it
does are the result of our genes. This does not mean that everything about
the brain/mind is innate (genetically determined), for some of the brain's
structure is the result of interaction with the world. But it is surprising
how much seems to be innate.
a. Our visual systems depend in an innate design specially adapted
to facts about how objects move, reflect light, etc. Vision would be impossible
if the brain were not to have this innate "knowledge".
b. Identical twins have astonishingly similar bodies AND minds.
c. There are universals in language and behavior that are found in
all cultures.
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It is pointless to debate what the contribution of nature (genetics) and
nurture (the environment and learning) is. Virtually all interesting behavior
is a complex mixture of both. What is interesting is to figure out the
mechanisms. For example, it is pointless to worry about whether adultery
is genetic or learned. There are no genes for adultery, but adultery is
not entirely learned either, since it depends on sexual attraction which
obviously has a genetic source.
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"Behavior itself did not evolve; what evolved was the mind." HMW p.
42
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Explanations in evolutionary psychology can be lame: p. 37 .For
example, men are bald and women not because bald men avoid being scalped
in battle. But that does mean we cannot get good explanations in evolutionary
psychology, for example the explanation of morning sickness (pp. 39
ff.).
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Explanations in evolutionary psychology are profoundly interdisciplinary.
p.
38 .
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Evolutionary psychology does not say everything about the mind is adapted
for a purpose, namely our gene's purpose, to perpetuate themselves. Organisms
can have their own goals that differ from the aim of our genes. For example,
genes explain our goals: to eat, reproduce, love, obtain protection, to
protect children, even to pay off a mortgage. But these goals are not to
be confused with our gene's goals.
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The theory of natural selection predicts that the human mind will no be
particularly well adapted to modern life. There has not been enough time
for significant genetic changes, and furthermore, modern culture tends
to take some evolutionary pressures out of the loop: example, with glasses
there is no longer pressure for good eyesight.
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It is the Naturalistic Fallacy to argue from what is the case to
what ought to be the case. Even if evolutionary psychology shows
that (say) violence is genetically programmed, that does not argue at all
that violence is good. Selection pressures and what is morally acceptable
need not coincide. So it is incorrect to argue against evolutionary psychology
on the grounds that it condones violence, war, adultery, racism or any
other feature of the mind that might have a genetic source.
F. Free Will
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One standard legal excuse for crime is to argue that the defendant was
not in control. His passions, or genes made him do it. Example: the Twinkie
defense.
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A scientific approach to the mind appears to eat away at the concept of
free will. p. 54
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Yet free will seems essential to moral responsibility.
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Therefore a cognitive scientist must take a compatibilist line on free
will: the line that free will is compatible with the idea that the brain/mind
obeys natural laws.
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One tactic for compatibilists is to argue that science and morality are
two separate spheres of reasoning.
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Garson claimed this tactic is not very satisfying since it does not allow
cognitive science to be of any help at all in the courtroom. Nor would
it allow cognitive science to aid in the process of trying to decide what
a good life for humans should be. These topics will be discussed further
in the last week of this course.
G. Class Exercise. Answer the following question.
Suppose that evolutionary psychology shows that violence is produced
by our genes. Does it follow that violence is not bad? What is Pinker's
response? Support your view with quotations from Chapter 1.