Transcript February 19

Motivation, Incentives,
Drives, and Rewards
Next:
Sleep, dreams, & emotion
© Kip Smith, 2003
Where we are at
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Psychology is the science of mind and
behavior
Behavior is directed at goals
Motivation orients the mind toward a
particular goal
There are two categories of things that
motivate:
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Incentives and drives
© Kip Smith, 2003
Goal-directed behavior
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Is oriented by the current combination of
incentives and drives
In order for behavior to be directed at a
specific goal:
If incentives are weak, the drive must be
strong
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This is what ‘character’ is all about
If the drive is weak, the incentives must
be strong
© Kip Smith, 2003
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This is what marketing is all about
Incentives and Drives
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External motives are called incentives.
Examples:
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Pay
Grades
Popularity
Internal motives are called drives.
Examples:
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Hunger
Sex
Curiosity
Self-esteem
© Kip Smith, 2003
Where we are going
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Today, a discussion of
some of the better
understood drives and
rewards and related
issues
Homeostasis
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Sex
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Next
Sleep & dreams
Emotion & arousal
Emotions
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Gender
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Rewards
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Hunger
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Money
Drugs
© Kip Smith, 2003
Anger
Anxiety, Fear
Disgust
Joy
Sadness
Surprise
Homeostasis: the fundamental
regulatory drive
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The body must maintain ± constant levels
of:
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Temperature
Oxygen
Water
Salt
Sugar
…
Homeostasis is the drive to maintain
those ± constant levels
© Kip Smith, 2003
Drives vary with time
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Sometimes you would rather sleep
Sometimes you just gotta eat
When you change your goal (e.g., from
sleep to food), something in your mind
has changed
One drive has become dominant
The other drives are still there but are not
determining your goal orientation
© Kip Smith, 2003
Tissue need
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Homeostatic drives seek to satisfy
metabolic goals
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You don’t meet the goal, you die
= ‘tissue need’
= a ‘regulatory’ drive (e.g., thermoregulation)
© Kip Smith, 2003
Elective (non-regulatory) drives
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Other drives seek to satisfy other types of
goals.
Example: self-esteem
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You don’t meet the goal, you don’t die
= an elective drive
These drives seek some other purpose
© Kip Smith, 2003
Maslow’s
hierarchy
of needs
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Homeostasis
Central drive systems
© Kip Smith, 2003
Functional differentiation
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Different drives are supported by different
neuronal networks in the brain
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E.g., The neural circuits that make you want to
eat are different than the circuits that make
you want sex
The neural circuits that support drives are
called central drive systems
© Kip Smith, 2003
The hypothalamus
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The hypothalamus is the part of the brain
that supports most central drive systems
Different parts of the hypothalamus
support different drives
How do we know this?
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Conduct the experiment in the Psych Inquiry
activity for Chapter 6 called The Hypothalamus
and Hunger.
Hand in the results next time
© Kip Smith, 2003
Rewards
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Real-time connotation
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Historical connotation
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stimuli and activities that create a behavioral
disposition to resist interruption of ongoing
behavior
stored representation of strength, rate,
amount, delay, kind, and spatio-temporal
distribution
Future-oriented connotation
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anticipation
selection of behavioral objectives
© Kip Smith, 2003
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Three ways to study the neuronal
basis for drives and rewards
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1
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Lesion studies
Stoke patients
Ablation in laboratory animals
2
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Stimulation studies
Electrical stimulation of specific bundles of
neurons
The foundational studies were done by Olds
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3
© Kip Smith, 2003
You are responsible for knowing the content of Old’s
review paper which is included in the paperback of
Scientific American articles.
Neuroimaging
1
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Lesion studies
Stroke patients often display abnormal
behavior, e.g., the sudden inability
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to swallow,
to speak,
to see the left side of everything
We can use neuroimaging techniques to
identify which parts of the brain have
been injured by the stoke
© Kip Smith, 2003
Relation between BSR & other
rewards
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Rewarding effect can compete with,
summate with, and substitute for
rewarding effect of natural stimuli such as
sucrose solutions
Rewarding effect is modulated by selfadministered drugs
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e.g., heroin, cocaine, & amphetamine all boost
the rewarding effect
© Kip Smith, 2003
A first pass
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Assessing the relationship between brain
reward circuitry in rats and the
anticipation and experience of reward in
humans
Trace circuitry underlying BSR in rats
By means of functional neuroimaging,
assess activation of circuit components in
humans performing reward-related tasks
© Kip Smith, 2003
BSR sites in the rat
© Kip Smith, 2003
BSR sites in the rat
medial forebrain bundle
(MFB)
lateral hypothalamus
(LH)
ventral tegmental area
(VTA)
© Kip Smith, 2003
Some cell groups implicated in BSR
"descending
path"
PPT = pedunculopontine
nucleus
DA = dopaminergic
VTA neurons
© Kip Smith, 2003
DA
PPT
© Kip Smith, 2003
3
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Neuroimaging takes pictures of the brain
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Neuroimaging
More exactly, of the demand for blood by
clusters of neurons
The assumption:
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The more active the neurons, the more energy
they need (O2, sugars, etc.).
Regional cerebral bloodflow responds to that
need
© Kip Smith, 2003
Brain Stimulation and
Neuroimaging Research
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Neuroimaging observations are
correlational.
Stimulation experiments assess causal
relationships.
© Kip Smith, 2003
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Read:
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Chapter 6
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Article 4 in the Scientific American
booklet:
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James Olds (1956). Pleasure centers in the
brain
Conduct the experiment in the Psych
Inquiry activity for Chapter 6 called The
Hypothalamus and Hunger
© Kip Smith, 2003