© Kip Smith, 2003

Motivation, Incentives, Drives, and Rewards

Next:Sleep, dreams, & emotion

© Kip Smith, 2003

Where we are at

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:

Incentives and drives

© Kip Smith, 2003

Goal-directed behavior

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 This is what ‘character’ is all about

If the drive is weak, the incentives must be strong

This is what marketing is all about

© Kip Smith, 2003

Incentives and Drives

External motives are called incentives. Examples: Pay Grades Popularity

Internal motives are called drives. Examples: Hunger Sex Curiosity Self-esteem

Psychology is more interested in drives Economics is more interested in incentives

© Kip Smith, 2003

Where we are going

Today, a discussion of some of the better understood drives and rewards and related issues

Homeostasis Hunger

Sex Gender

Rewards Money Drugs

Next Sleep & dreams Emotion & arousal Emotions

Anger Anxiety, Fear Disgust Joy Sadness Surprise

© Kip Smith, 2003

Homeostasis: the fundamental regulatory drive

The body must maintain ± constant levels of:

Temperature Oxygen Water Salt Sugar …

Homeostasis is the drive to maintain those ± constant levels

© Kip Smith, 2003

Drives vary with time

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

Homeostatic drives seek to satisfy metabolic goals

You don’t meet the goal, you die = ‘tissue need’ = a ‘regulatory’ drive (e.g., thermoregulation)

© Kip Smith, 2003

Elective (non-regulatory) drives

Other drives seek to satisfy other types of goals.

Example: self-esteem 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

Homeostasis Central drive systems

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Functional differentiation

Different drives are supported by different neuronal networks in the brain

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

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? 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

Real-time connotation stimuli and activities that create a behavioral

disposition to resist interruption of ongoing behavior

Historical connotation stored representation of strength, rate, amount,

delay, kind, and spatio-temporal distribution

Future-oriented connotation anticipation selection of behavioral objectives

© Kip Smith, 2003

Three ways to study the neuronal basis for drives and rewards

1 Lesion studies Stoke patients Ablation in laboratory animals

2 Stimulation studies Electrical stimulation of specific bundles of

neurons The foundational studies were done by Olds

You are responsible for knowing the content of Old’s review paper which is included in the paperback of Scientific American articles.

3 Neuroimaging

© Kip Smith, 2003

1 Lesion studies

Stroke patients often display abnormal behavior, e.g., the sudden inability

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

Rewarding effect can compete with, summate with, and substitute for rewarding effect of natural stimuli such as sucrose solutions

Rewarding effect is modulated by self-administered drugs

e.g., heroin, cocaine, & amphetamine all boost the rewarding effect

© Kip Smith, 2003

A first pass

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

medial forebrain bundle(MFB)

lateral hypothalamus(LH)

ventral tegmental area(VTA)

BSR sites in the rat

© Kip Smith, 2003

PPTDA

"descending path"

Some cell groups implicated in BSR

PPT = pedunculopontine nucleus

DA = dopaminergic VTA neurons

© Kip Smith, 2003

© Kip Smith, 2003

3 Neuroimaging Neuroimaging takes pictures of the brain

More exactly, of the demand for blood by clusters of neurons

The assumption: 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

Neuroimaging observations are correlational.

Stimulation experiments assess causal relationships.

© Kip Smith, 2003

Read:

Chapter 6

Article 4 in the Scientific American booklet: James Olds (1956). Pleasure centers in the brain

Conduct the experiment in the Psych Inquiry activity for Chapter 6 called The Hypothalamus and Hunger

Hand in the results next time