The Brain (Pt. 1)
P S YC H 1101 P ROF. DAVID P IZ AR RO DAY 5
www.cornellpsych.net
So Far… •
psychology is the application of scientific method to the understanding of the human mind (how and why we think, feel, behave)!
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breadth in the levels of analysis with which we can explain the mind! variety in the methods that are used! today: why did it take so long for psychology to become a science?
V. S . R AM AC H AND R AN http://w w w.ted.co m/t alk s/v ila yanu r_ r amachandr an_ o n_ yo u r_ mind.html
Psychology And The Brain: Some Basic Assumptions •
The brain is a natural phenomenon, and is therefore open to scientific investigation!
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The brain is the immediate cause of our thoughts, feelings, and behaviors--the things that psychologists study.!
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Therefore: !
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Psychology is open to scientific investigation! To understand psychology (at one level of analysis, at least) we ought to understand the brain.
Neuroscience Vs Psychology !
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Neuroscience is the study of the brain (the structure and function of the nervous system)!
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Psychology is the study of the mind. !
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We seek an understanding of how the brain works as a way to inform our mental life.!
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Cognitive Neuroscience, Social Neuroscience, Clinical Neuroscience, Affective Neuroscience!
Many questions in psychology are not adequately answered at the level of analysis of the brain. (hardware vs. software)!
Why did it take so long for psychology to become a science?
The “Astonishing Hypothesis” “The Astonishing Hypothesis is that "You," your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules. As Lewis Carroll's Alice might have phrased it: ‘you're nothing but a pack of neurons.’ This hypothesis is so alien to the ideas of most people alive today that it can be truly called astonishing.”
FR ANC IS C R IC K
Philosophical Dualism
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R E NE E D E S C AR TE S ( 15 9 6 -16 5 0 )
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Bodies are physical. Minds are immaterial.!
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“I knew that I was a substance the whole essence or nature of which is to think, and that for its existence there is no need of any place, nor does it depend on any material thing … that is to say, the soul by which I am what I am, is entirely distinct from body.”
“Common Sense” Dualism
PAUL BLOOM
“Our dualistic conception isn't an airy intellectual thing; it is common sense, and rooted in a phenomenological experience. We do not feel that we are material things, physical bodies. The notion that we are machines made of meat, as Marvin Minsky once put it, is unintuitive and unnatural. Instead, we feel as if we occupy our bodies. We possess them. We own them. Because of this, we talk about my brain, or my body, using the same language of possession that we use when we talk about my car, or my child. These are things that we possess, that we are intimately related to—but not what we are.”
Dualism Seems Right • •
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We naturally use dualistic language! “my arm” “my hair” “my brain”!
Intuitions about personal identity! Body-swapping is not hard to understand! Nor are multiple identities in one body (e.g., Sybil)
Fu tu r ama S06E 10: “ The P r iso ner o f Benda”
Dualism Seems Right • •
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We naturally use dualistic language! “my arm” “my hair” “my brain”!
Intuitions about personal identity! Body-swapping is not hard to understand! Nor are multiple identities in one body (e.g., Sybil)!
Belief in intelligent entities without bodies
Dualism Seems Right •
We naturally use dualistic language!
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Intuitions about personal identity!
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“my arm” “my hair” “my brain”!
Body-swapping is not hard to understand! Nor are multiple identities in one body (e.g., Sybil)!
Belief in intelligent entities without bodies! Survival of the self after the death of the body
Most Scientists Reject Dualism • • •
It is a problematic view to defend, even philosophically! We are aware of what physical things (e.g., computers) are capable of doing! Most importantly, it is more obvious than ever that our minds are linked to our brains in a necessary way
Brain Damage = Mind Damage
Localized Psychological Processes
Drugs That Alter Brain Chemicals
How Does The Brain Work?
Neurons • • • •
About 86,000,000,000! Sensory (afferent) neurons, motor (efferent) neurons, interneurons! All-or-nothing! Intensity: expressed through number of neurons firing and frequency of firing
Neurons •
Communication over synapses; axons release neurotransmitters!
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excitatory! inhibitory!
Drugs: agonists vs. antagonists!
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curare! alcohol! amphetamines! Prozac! L-DOPA
Next •
More detail on the brain and psychology!
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Neurotransmitters and their role in what we think, feel, and do! Structures of the brain and how they are implicated in psychological functioning!
Learning about the brain through damage and disorders