chapter 1 Flashcards
A meta-theory defines
What psychology should study
The methods and standards of evaluation in the field
The kinds of theories that are acceptable in the field
Psychology is not unified by a single meta-theory
There are many different research and clinical
“cultures” in the field
Behaviorism
a philosophy (or a meta-theory) adopted by many researchers and clinicians.
Characteristics of theories
Seek to explain observable data
Theories can involve unobservable entities, forces,
or processes to explain observations.
The best theories are more precise and predict more
data (theories are “better” if they predict more)
Parsimony: If two theories predict data equally well,
the simpler theory is usually preferred.
The cognitive perspective
utilizes intervening variables,
usually in the form of hypothesized cognitive structures or processes (theoretical entities), to help explain behavior.
These variables come between an environmental event and a behavior
these unobserved theoretical entities are the direct
causes of behavior
Beliefs Sensory, short-term, long-term memory systems Cognitive schemas Expectations Semantic Networks Plans Goals/Desires A whole system of hypothesized “Cognitive Architecture”
Problems with cognitive theories
Introspection is often unreliable
Unparsimomious (think of all those mental entities)
Just where & what are those “minds” anyway?
Unobserved germs were still thought to exist in space.
But where are minds?
Reasoning from mental entities is often circular
Behaviorism in Psychology
Behaviorism in psychology is associated with John B. Watson and B.F. Skinner. The approach of B.F Skinner is the guiding meta-theory for behaviorists today. This approach is called Radical Behaviorism. Some call themselves Contextual Behaviorists.
Skinner’s Radical Behaviorism
Emphasizes the influence of the environment on
behavior, rejects the use of internal events to explain
behavior, and views thoughts and feelings as behaviors
(responses) that themselves need to be explained.
Basically, the environment simultaneously influences
overt behavior and private events.
These private events are not causal: they are just a
response like overt behavior—but only one person can
observe them.
Skinner distinguished public vs private responses by
appealing to exteroceptive vs interoceptive nervous
systems
Public vs Private
Exteroceptive Nervous System: nervous system with
sensory receptors for picking up energy from the external
world (public events).
An external stimulus can trigger the exteroceptive system of many
people.
We can all see and hear things in the external environment.
Interoceptive Nervous System: nervous system with
sensory receptors connected to muscles, joints, internal
organs – i.e., detecting energy from sources underneath
our skin.
Only I can experience my headache or stomach growling.
Does your philosophy (meta-theory) matter?
Yes, it can influence how you do research and how
you work in clinical practice.
An example: Understanding and treating depression
from two different meta-theories
Seligman’s Learned Helplessness Theory:
Depression is caused by being in a punishing (aversive)
environment in which you learn that nothing you do can change
things for the better.
Theory based on Seligman’s escape-learning research with dogs
if dogs are first given inescapable shocks for a while, in
which nothing they do leads to relief, they will stop doing anything,
curl up and whimper.
Even when new conditions arise in which escape from the shock is
easily available, these dogs will not even try to find a means of
escape.
They have learned to be helpless.
Peter Lewinsohn’s Behavioral Theory
Depressed people have low levels of positive
experiences (rewards, reinforcements) from their
environments.
Initial event (trauma, loss, defeat) disrupts their usual
behavior, making them less successful in receiving
reinforcements.
They stay isolated and confined, often in an
impoverished (unpleasant) environment
After depressed, people avoid them (they become
aversive to others, e.g., smell bad, sigh and complain)
Behavioral Activation Therapy
Targets patient apathy and inertia: Get them moving.
Assign activities (in small steps) to help them clean
up their act and eventually get out into the world
where “good things” might follow.
Assign homework for accomplishing simple activities
that are easily accomplished and are rewarding (e.g.
brushing teeth, bathing, making bed, taking out
garbage, washing dishes, etc.)
Therapists uses reinforcement (e.g., praise) to help
get them going and to increase their activities over
time.
What are some behavioral explanations for
why CBT might work?
1. The cognitive therapist, if kind and supportive, might
be a source of reinforcement for Mary (reinforcing her
returning to therapy)
Perhaps if they played cards together and had fun, instead of
challenging her beliefs, Mary might still improve.
Her beliefs (private events) change due to her new positive social
environment: her experiences are more positive, so her thoughts
are more positive.
2. Mary is now getting out of the house to go to therapy.
Perhaps she will have some pleasant experiences before
or after therapy.
3. As Mary stops talking so negatively and cleans up a
bit, she is less likely to drive other people (potential
reinforcers) away.
Cognitive Treatment
Assessment : What’s going on in your mind?
Treatment: Change what’s going on in your mind.
Therapist Role:
Reality check
Debater
Mind changer.
Behavioral Treatment
Assessment: What’s going on in your life (people & events)?
Treatment: Change what’s going on in your life.
Therapist Role:
New part of your social environment (potential reinforcer)
Housekeeper: help make the environment more rewarding
Trainer: Teach new skills for getting reinforcement and avoiding bad
outcomes
Behavior Analysis
Two Branches
Experimental Analysis of Behavior
Focus on discovering basic principles of behavior and learning
Research done in a laboratory environment with both humans
and nonhumans
Applied Behavior Analysis (ABA)
Helping improve lives by identifying significant behavior and its
controlling environmental variables
Research done in “real world” environments with humans
SAFMEDS
SAFMEDS trains for fluency of responding
Fluency = accuracy + speed
SAY ALL FAST
MINUTE EACH DAY
SHUFFLE
Go through a stack of cards as fast as you can, giving
the answer out loud.
Do as many as you can in 1 minute (put missed cards
in a separate stack; review them later).
Shuffle the cards and do it again (see clip).
Seems to be effective for vocabulary; don’t know about
complex relations among ideas.
Learning
Learning is a change in the behavior of an organism due to experience.
Behavior is anything that an organism does that can be measured.
(Some definitions use “a relatively lasting change in the behavior . . .”)
“due to experience”?
Roughly, we mean exposure to environmental events.
Exposure to the textbook and lectures could lead to a relatively permanent change in your behavior: What you do, what you think, how you feel. You will have learned about learning.
Exposure to electric shocks while eating a favorite food could lead to a relatively permanent change in a rat’s behavior when it smells that food. It has learned to fear and avoid the food.
Exposure to praise and smiles after a child has cleaned her room could lead to a relatively permanent change in the child’s housekeeping tendencies. The child has learned to be tidy
Stimulus & Response (S-R terminology)
A stimulus is any well-defined, physical event that can potentially influence behavior.
Examples:
food, stop signs, human touch, sound of a bell, odors Stimuli can originate inside the body: ruptured spleen A response is behavior that is predictably associated with a stimulus.
Examples:
salivation, putting on the brakes, feeling happy, answering the phone, opening a bottle of perfume, crying & feeling pain
Change: Environmental and Behavioral
Organisms live in specific environments and must adapt to those environments to thrive.
Problem: Environments change.
Slow Changes (beyond the life of individual organisms):
Continental drift, ice ages, global warming (?), deforestation, depopulation
Changes during a lifetime
Natural disasters, weather, predators, illness
Solutions: Organisms must change.
Change
Species Change: Evolution by Natural Selection Gradual change in the distribution of physical and behavioral characteristics in populations of organisms.
Individual Change: Learning
Natural Selection
Natural selection is NOT a theory of the origins of nature or the origins of life.
It is a theory of changes in characteristics of a species (called adaptations), and potentially of the origins of new species (called speciation).
Natural Selection 2
Natural selectionis an evolutionary process through which adaptive traits are passed on to ongoing generations because these traits help animalssurvive and reproduce.
Evolution: Try Things, Keep What Works
Natural selection follows the process:
Try things (genetic variations)
Keep what works (selection of adaptive traits)
Through natural selection, a number of broad classes of behaviors can be found in different species of organisms
Reflexes
A reflex is an automatic relationship between a specific event and a simple response to that event.
Often protect organisms from injury.
Example: Withdrawal reflex
Also: *startle response *eyeblinks *tears *sneezing *vomiting
Phenomena Assoc/w Reflexes
Sensitization: Eliciting a reflex often leads to an initial increase in the probability or intensity of a response to the same (or closely related) stimuli.
Loud noises can elicit the startle response (jump).
We are more likely to startle again immediately afterword to even weaker noises.
Sensitization is most likely to occur with very intense stimuli (potential danger).
Phenomena Assoc/w Reflexes
2
Habituation: Repeatedly evoking a reflexive response over time will often weaken or decrease the probability of a response to the same stimulus.
More likely to occur with mild to moderate intensity stimuli (not perceived as dangerous), Evgeny Sokolov: the orienting response (OR) in dogs New Stimulus looking toward stim., ears lift, wave of neural and physiological activity (HR, breathing, etc)
With time, OR fades; appears that organism no longer aware of stimulus.
Modal (Fixed) Action Patterns
MAPS
A series of interrelated actions found in most members of a species, usually triggered by specific stimuli (called “releasers,” or “releasing stimuli”)
Usually involves the whole organism (unlike reflexes, which often involve specific muscles or glands).
Are more complex than reflexes, extended over a longer period of time.
They are stereotypical, but more variable than reflexes.
Although the behaviors are innate, they can be somewhat modified through experience (getting better at the task).
Example MAP
Examples: Spider web spinning Bird nest building Egg rolling in birds to retrieve eggs that have fallen out of a nest. Courtship & mating dances
General Behavior Traits
Broad behavioral tendencies that occur across many situations (not specific releasers).
Often highly heritable:
Activity Levels
Sociability (tendency to approach and interact with others— highly variable in young children)
Emotionality (e.g., fearfulness)
Basically, temperament and personality by another name.
Domesticated & wild fox breeds differ in temperament
Learning
Reflexes, MAPS, and General Traits are often adaptive. They have likely evolved over centuries and perhaps help organisms coping with their average expectable environments.
But there are still day-to-day surprises, changes within an individual’s lifetime.
The capacity for flexible change in a lifetime is probably an evolved capacity as well.
Learning is Evolved Modifiability.
Behavioral Repertoire
a catalogue of behaviors (including reflexes, MAPS, and complex learned behaviors) that are characteristic of a species or individual.
Operational Definitions
To study specific behaviors (and their changes), we must define the behaviors.
In behavior analysis (and science in general), we define variables in terms of how they are measured—i.e., by the operations that are used to measure a behavior.
e.g.: When has a person learned to hit a golf ball?
Ball is off the tee?
Does a 30 yard “worm burner” count?
At least 50 yards off ground and in the fairway?
Topography
the shape or form of a behavior. When the shape of a behavior resembles the shape of a model or goal, learning has occurred.
(For typing, compare documents with format of a standardized test document)
Intensity
the strength of a behavior.
Sometimes the goal is to increase or to decrease intensity
(e.g., learning to kiss).
Speed
the time it takes to perform a task or reach a goal. (Typing? Perhaps the time it takes to complete a document without errors)
Duration
The length of time that an individual repeatedly or continuously performs a certain behavior.
This measure is appropriate when the aim is to either increase or decrease how long a behavior occurs.
Example:
How many hours a student studies
Latency
The length of time required for a behavior to begin.
Examples:
How soon a dog begins salivating after it hears a tone How soon a child begins to make his or her bed after being told to do so.
Rates of Behavior [the importance of “per”]
A frequencyis a simple count of how many times a behavior is observed to occur.
Simple frequencies are often less informative than rates
How many parking tickets have you had?
5
5 in 10 years?
5 this week?
Rate is a frequency standardized (often by time)
Miles per hour
Responses per minute
Errors per page
Research Designs in Learning Non-Experimental Research
Descriptive or Correlational Researcher does not manipulate any variables, simply records behaviors to see if they are related (e.g., measure study habits and grades—see if they are related).
Can’t infer causality with much certainty.
Research Designs in Learning Experimental Research
Researcher manipulates an environmental variable.
Measures the effect of the manipulation on behavior. Aimed at establishing cause and effect.
Experimental Research: Terminology
Independent Variable The variable that the researcher manipulates.
The hypothesized cause of behavior change (from a behavioral perspective, generally an environmental stimulus) Dependent Variable
The outcome variable (behavior) that is expected to change as a result of the manipulation.
IV DV
Between-Subjects Experiments
Involves at least two groups of subjects.
Subjects randomly assigned to groups to make them equal on a variety of extraneous variables.
One group (Experimental Group) gets exposed to a manipulated variable (e.g., new teaching method; rewards for correct responses; electric shock for wrong responses).
The other group (Control Group) is not exposed to the manipulation.
Compare the groups on the DV. Did exposure to the manipulation lead to differences in behavior between the groups?
Between-Subjects Experiments
group membership
•Group membership should be determined by a random processto help ensure that the two groups are roughly equalon observed and unobserved variables at the beginning of the experiment.
Characteristics of Between-Subjects Designs
Data in each group are averaged; you are comparing average change or differences between the two groups.
Individual variations around the average treated as statistical “noise.”
Large samples and complex statistics are often needed to detect an effect of the manipulation.
Within-Subjects Designs
No separate groups of subjects: each subject will serve as “his or her own control.”
Each subject is assessed before the manipulation (baseline measures), then the IV is applied to all subjects, and each subject is measured again.
Determine whether there was change in behavior from baseline to the next measurement period.
Within-subjects designs can involve large groups (but fewer are needed on statistical grounds).
Data can be averaged and tested statistically—the average change of the subjects.
But within-Ss designs can also be applied to individuals.
Behavior Analytic “Research Culture”
Behavior analysts are very fond of within-subjects research designs
Often present data for only a few subjects (sometimes only 1 subject).
Seldom average data across subjects (show each subject’s data individually).
Graphical displays preferred.
They dislike complex statistical analyses.
In these preferences they are imitating Skinner.
Simple within-subjects designs used in behavior analysis
Suppose a child is having trouble staying on his assignments in the classroom.
You might decide to give the child a dime for every minute he keeps focused on his work.
The simplest design to test the intervention is called an AB design.
Problem with AB Design
Something other than the experimental manipulation might have caused the change.
Confound—an extraneous variable (something other than the manipulation) that actually causes the DV to change.
A teacher is using the Whole Language technique to help Stephanie learn to read faster.
After two months, Stephanie’s reading fluency increases dramatically from the baseline period.
But, unknown to the teacher, Stephanie’s grandmother had started to teach Stephanie to read using old-fashioned phonics methods (sounding out the words).
Problems with Reversal Designs ABA, ABAB, etc.
Not useful if the learning is irreversible (i.e., doesn’t go back to baseline after manipulation stopped)
Ethical issues in withdrawing manipulation
e.g., if the DV is head banging in a child, and the manipulation decreases head-banging, is it ethical to remove the manipulation?
Multiple Baseline Designs
3 types
Across participants Same settings and behavior, but different participants
Across behaviors Same participant and setting, but different behaviors measured (or the same behavior measured in different ways)
Across settings Same participant and behavior, but different settings
Elicited Behaviors
behaviors that are automatically,
involuntarily produced in response to a particular
stimulus.
Elicited Behaviors: 2
Often of an emotional or physiological nature, based on
the autonomic nervous system that regulates heart rate,
digestion, breathing, and other automatic functions.
These responses seem to happen to us
sweating, salivating, feeling angry or happy or afraid
These responses are primarily studied in Classical
conditioning.
Ivan Pavlov (Russia) and John Watson (US)
Emitted Behaviors
behaviors that we typically
describe as voluntary, under our control,
purposeful
Emitted Behaviors: 2
Often associated with the somatic nervous system
These are things we do. Taking a walk, writing a letter, raising our hand in class,
doing situps, driving our car
These behaviors are primarily studied in Operant
Conditioning.
Edward Thorndike & B.F. Skinner focused on these.
The Basic Form of Classical Conditioning
A mechanism for learning with wide-ranging
implications for our emotional life.
In classical conditioning, one stimulus that does not
initially elicit a response (neutral stimulus) is associated
with a second stimulus that does.
As a result, the first stimulus also comes to elicit a
similar response.
Ivan Pavlov (1849-1936)
Russian Physiologist Specialty: Digestion Nobel Prize, 1904, for his work on the digestive system b. Ryazan, Russia Father was a poor orthodox priest Started as seminarian. Left to study physical sciences, U. St. Petersburg
Pavlov’s accidental discovery
Wanted to measure quantity and composition of
saliva in response to food in mouth.
Problem: dogs began to salivate before food was
administered, to everyone’s annoyance. Salivated researchers, door opening, footsteps, bowl
Pavlov called this phenomenon “Psychic
Secretions”
He realized he had discovered something
psychological, and, after much debate, directed his
research to understanding this phenomenon.
Nice Notation….
US UR (the unconditioned reflex pair)
N : US UR (pair a neutral stim. with the US)
CS CR (CS elicits response; now called CR)
Food Salivation
Tone : Food Salivation
Tone Salivation
The UR and CR are always the same response (or at least
similar), but elicited by different stimuli.
Of what use is Pavlovian conditioning?
Based on our experiences, classical condition builds
a set of signals or predictive cues for potentially
important things to come.
Builds an “early warning system”: we become
physiologically prepared for what might be coming
next.
Unconditioned reflexes tend to be automatic
adaptive, species-wide responses.
Classical conditioning evolved to add flexibility to
our responses (take context into account).
Factors that affect conditioning
Pairing CS and US (4 ways) Contiguity (closeness in time) Contingency (predictive value of CS) Stimulus Features Overshadowing: Salience, intensity of stimuli Sensory preconditioning Prior Experience Latent Inhibition Blocking Number of Pairings Inter-trial Interval
Ways to pair CS and US
Delayed conditioning
Trace conditioning
Simultaneous conditioning
Backward conditioning
Delayed Conditioning
The onset of the CS precedes the onset of the US, and
the two stimuli overlap. Example:
first present a tone and then, while the tone is still on, present the air puff
Trace Conditioning
The onset and offset of the CS precede the onset of the
US.
The CS begins and ends before the US, and the two stimuli
do not overlap.
The organism has to “remember” the occurrence of the
tone (“memory trace”) to be able to associate the CS and
the US
Simultaneous Conditioning
The onset and end of the CS and the US are
simultaneous.
Example:
a tone and puff coincide exactly in time
Backward Conditioning
The US is presented first and the CS is presented
afterward.
i.e., the US comes before the CS
Example:
Puff of air comes first, then the buzzer
Food is presented, then a bell sounds
Which pairing works best?
All things being equal, delayed conditioning is most
effective.
Followed very closely by trace conditioning.
Simultaneous conditioning is weak.
Backward conditioning is the weakest, almost
impossible for many organisms.
Why are the last two so ineffective?
They do not signal what is coming up.
Best to worst: DTSB
Another Factor: CS-US Contiguity
Contiguity—closeness in time between two events.
In classical conditioning, CS-US contiguity refers to
the interval of time between the CS and US.
Contiguity is defined differently for trace and
delayed conditioning
Trace Conditioning
Trace conditioning is best when the trace interval is relatively short (no more than a few seconds). Trace interval is the time between the offset of the CS and the onset of the US.
interstimulus interval (ISI) i
Delayed conditioning is best when the interstimulus
interval (ISI) is relatively short.
The interstimulus interval (ISI) is the time between the onset of
the CS and the onset of the US.
Rule of Thumb: Make the ISI as short as
possible, just short of simultaneous
presentations.
Another Factor: Contingency
Contingency is related to prediction—does one
event, A, predict another event, B
If A, then B
In classical conditioning, it has to do with the
consistency of pairing CS and US. If CS, then US (follows)
If the CS is always followed by US, you have
perfect contingency.
Contingency: Robert Rescorla (1968)
Rats Shock (US) Fear (UR) CS = Tone Four conditions CS always paired with US (perfect contingency) CS NOT paired with US 10% of time NOT paired 20% of time Not paired 40% of time (weak contingency)
Stimulus Features & Overshadowing
Almost any stimulus that can be detected can become a
CS, but some are more conditionable than others.
Compound Stimuli Studies of Pavlov
Two or more CSs presented at the same time just before the US
is presented.
[Tone & Light] : Food Salivation
Each CS then tested individually
Often, only one of the stimuli shows strong conditioning Overshadowing – if one CS is more intense or salient, the other
CS may be “ignored”
Strong light better than weak tone
Loud tone better than dim light
Sensory Preconditioning
Sensory preconditioning is another example of stimuli
influenced by compound events.
• Sensory Preconditioning- two stimuli such as a light
and tone are repeatedly presented together without the
occurrence of a US (preconditioning).
• Later, only one of these stimuli (e.g., tone) is
repeatedly paired with a US (e.g., a shock).
• Next, the other stimulus (light) is tested for
conditioning.
• Even though the second stimulus (light) was never
directly associated with the US (shock), it comes to
evoke a conditioned response as well.
Prior Experience with CS
Suppose you present a CS (e.g., a tone) repeatedly all by
itself (never with a US like food or shock).
You then start pairing the CS with a US, trying to
establish conditioning.
How will the conditioning compare to standard
procedures (where the CS isn’t at first repeatedly
presented alone)?
In general, learning is slower.
Latent Inhibition:
The repeated appearance of the CS
without the US seems to inhibit the ability of the CS to
elicit the conditioned response.
Why does latent inhibition occur?
Remember contingency effects: learning is stronger when
the CS predicts the US (if CS, then US) a greater
proportion of the time.
In latent inhibition, there is no contingency during the
initial pre-exposure period.
Basically, since the CS seems unrelated to the US for a
while, it takes more contingent presentations (if CS, then
US) before the organism “believes” there is really a
relationship.
A completely new stimulus is a better CS than an older
stimulus that didn’t seem to predict a US in the past.
Blocking in Compound Stimulus Studies
Leon Kamin discovered that sometimes a new CS
cannot be established effectively.
This occurs when this new CS is part of a
compound stimulus study with a previously
established CS.
Blocking vs Overshadowing
Blocking resembles overshadowing, in which
one CS in a compound stimulus gets
overshadowed by a stronger or more salient CS.
In overshadowing, both stimuli (CSs) in the
compound are new stimuli.
But in blocking, one of the CSs is previously
established and is known to elicit the CR.
In blocking, the presence of an established CS
blocks the conditioning of another CS.
Why Blocking?
In blocking, the new CS often doesn’t add anything
more to the established CS in predicting the US.
You have an employee who can predict the stock
market with 100% accuracy.
Would you hire another employee for the same job?
No, the new employee would be redundant (offering
no new information).
So, once a CS is an established predictor (a light), a
new predictor (tone) is unnecessary.
Number of Pairings (Trials)
Each pairing of a CS with a UC is a trial. The more trials conducted, the stronger the learning (sort
of obvious).
But the amount of learning that occurs over repeated
trials is not linear—i.e., growth in learning is not constant
over trials.
Learning occurs more rapidly during early trials, but there
appears to be diminishing returns for one’s efforts after a
while.
Intertrial Interval
The intertrial interval (ITI) is the time between each
conditioning trial.
Recall that the shorter the interstimulus interval (ISI), i.e.,
when the CS is closer to the US in time, the better the
learning.
But what about the interval between trials (ITI)? Is
learning stronger when the time between trials is brief
(say, 5 seconds) or longer (say, 20 seconds)?
Counter-intuitively, more time between trials often
produces better learning.
Similar to the fact that we learn more when we spread
our study hours out over time (distributed practice)
Learning and Age
Age: Older organisms do not condition as readily as younger organisms. This is not just Granny being unable to learn to use a computer. Even eye-blink conditioning is slower with age.
Why is learning better under stress?
Anxiety and stress occur around important or
salient events, so it is adaptive to have more
efficient learning at these times.
Better to establish cues (early warning system)
for situations that are potentially harmful or
beneficial.
Note: Stress hormones like cortisol consolidate
memory (e.g., flashbulb memories for traumatic
events)
Learning, then losing it: Extinction
Continued pairing of CS (tone) with US (food)
maintains the CR (salivation), i.e., the learning is
maintained.
Repeated presentation of the CS without US leads
to a weakening and stopping of the CR: this is
called Extinction of the CR.
Spontaneous Recovery
After complete extinction, let time pass
Present CS again by itself
Temporary, small return of CR
After successful treatment for phobias or drug cravings,
there will often be “flare-ups” later when exposed to the
old CSs. Expect this as a clinician.
Reacquisition
Establish a CSCR connection.
Extinguish CR by presenting CS alone.
Try to establish the CSCR connection again.
Will the learning be quicker or slower than in the
original conditioning trials?
Opinion?
Conditioning the second time around is much
quicker. Fewer trials required than the original
learning prior to extinction.
Theories of Classical Conditioning
There are several theories of classical conditioning,
none of which is universally accepted.
S-S (stimulus-stimulus) theories
S-R (stimulus-response) theories
The Rescorla-Wagner theory (mathematical model)
of conditioning.
S-S and S-R Theories
Both of these theories ask, “What associations are
learned in classical conditioning?”
S-S theories propose that a connection between the
CS and US is learned (between bell and food).
S-R theories propose that a connection between the
CS and the CR is learned (between bell and
salivation).
Both make proposals about neural connections in
the brain that get established through learning trials. There is no actual evidence from brain research to support any
theory of classical conditioning
S-S Theories
The CS becomes directly associated with the US
and comes to elicit the same response that is
initially related to the US.
Example:
A child who is bitten by a dog associates the dog (CS)
with the bite (US). Because of that association, the child comes to fear the
dog (CS)
Pavlov’s Substitution Theory
Pavlov’s own theory of classical conditioning is called
Substitution Theory
This is an S-S Theory
In classical conditioning, the CS becomes a substitute
for the US, which means the CS triggers the same
response as the US.
Problems with Substitution Theory
If substitution of CS for US is what is really
happening, then CR should be the same as the UR
A lot of time, this does happen, but not always
The CR is usually weaker than the UR
More troubling, however, is that the form of the CR
sometimes differs from the form of the UR.
Problems with Substitution Theory 2
When dogs are presented with food powder, they
salivate, but they also make chewing motions and
remain calm.
If a tone is paired with the food powder, dogs will
salivate to the tone, but they do not make chewing
motions, and they become agitated .
So the overall pattern of activity is different for UR
and CR.
Preparatory Response Theory
Greg Kimble (1967) introduced Preparatory Response
Theory to explain why the natural unconditioned
response (UR) often differs in some respects from the
learned conditioned response (CR).
The UR is designed to deal with the unconditioned
stimulus (US).
For example, salivation and chewing (UR) help with
swallowing the food (the US). Helps break down and swallow
the food.
The CR, however, helps prepare for the US.
When a bell signals that food (US) is on its way, the CR is just
salivation. There is no need to chew, because there is nothing
yet to chew.
Preparatory Response Theory 2
How does this apply to a rat’s jumping then freezing
when shocked, versus just freezing when the bell rings?
The UR to pain is to first jump, then freeze. Rat’s aren’t
shocked in nature, but they are often bitten (the first
step to being eaten).
By jumping when the pain is felt, the rat might escape
the jaws of a predator. Then it should freeze so it isn’t
noticed.
However, when a bell indicates that a bite is perhaps on
its way, it’s better to just freeze (and not be noticed by a
predator).
If you jump before the predator has to be dealt with, you might give your
location away.
S-R Model (Not in Book)
The CS becomes directly associated with
the UR (and is now called a CR).
Example:
When bitten by a dog (US), a child associates
the dog (CS) with the pain and fear (UR) that
were elicited by the bite (US).
She experiences fear (UR) when she next
encounters the dog (CS)
No established neurological basis.
Simply remains a theoretical possibility
awaiting evidence.
Rescorla-Wagner Model: A Mathematical Model
of Classical Conditioning
ΔVn = c( λ – Vn-1)
ΔVn = amount of change in associative strength on trial n
Vn-1 = associative strength on the previous trial
λ = Vmax = maximum possible associative strength
c = salience/intensity of the CS (with higher values meaning
greater salience/intensity).
R-W and compound stimuli
Competitive learning: The total learning available, λ , must be shared by each stimulus in a compound. Thus,
the amount of learning to each stimulus is less in a
compound than if that stimulus is alone.
Rescorla-Wagner 2
Good mathematical model, accounting for
Nonlinear learning curves with upper limit Salience/intensity of CS Extinction Overshadowing Blocking
But, doesn’t account for
Latent Inhibition (effects of prior exposure)
Spontaneous Recovery
Interpreting the RW model (know this)
Although RW is a mathematical model, an intuitive
interpretation is often given:
Learning occurs fastest when the pairing of a CS
(bell) with a US (tone) is new, unexpected,
surprising.
[In the model, this is when ( λ – Vn-1) is large.]
The more the CS & US are paired (thus expected
and boring), the slower the learning.
Understanding Phobias
Phobias seem to represent a process of over generalization. • A conditioned fear response to one event (often truly dangerous) has become overgeneralized to other (harmless) events. – This was first demonstrated by John B. Watson and his student (and wife-to-be) Rosalie Rayner in 1920.
Freud and Little Hans
Hans was a 5 year old boy with a severe phobia of horses: he was specifically afraid that a horse would bite him.
• Hans eventually was afraid of leaving the house.
• Freud’s eventual interpretation: • Horses were symbolic of Hans’ father.
• The fear of being bitten was a disguised fear relating to the Oedipal conflict, namely the fear that the father (horse) would castrate Hans (bite him) because of Hans’ desires for his mother.
• Watson hated this sort of explanation.
Little Albert
At Johns Hopkins University, Watson & Rayner conditioned a fear response in an 11-month-old infant named “Albert B.,” now simply called “Little Albert.”
• Before the training, Albert seemed to display an unusual level of emotional stability—he seemed fearless to almost all stimuli presented to him.
• For Watson and Rayner, this was an advantage:
– If they could create a phobia in a fearless child, they would have a stronger case for the importance of environment & learning (as opposed to innate biological propensities).
Real Life Phobias
Often the development of phobias requires only one pairing of the CS with an intense US to become established. • Many people with phobias are unable to recall any particular conditioning event before the development of their symptoms.
• Without treatment, phobias often grow worse over time, a process called incubation.
• Most people exposed to extremely frightening events do not develop phobias.
• Personality differences: introverts and highly anxious people (neuroticism) are more prone to phobias.
Treating Phobias
Although Watson was not able to treat Little Albert for his lab-induced phobia, we can guess how he might have done so. • Recall what Pavlov demonstrated: After a dog was conditioned to salivate to a bell (CS) by pairing the bell with food (UCS), the conditioned salivation (CR) could be eliminated by repeated presentation of the bell without the food. • Watson was certainly aware of this phenomenon of extinction, first demonstrated by his hero Pavlov.
Exposure Therapies
Exposure therapies rely on exposure to feared objects or situations under conditions of safety.
• Exposure therapies are the treatment of choice (among behavioral and cognitive-behavioral therapists) for phobias, OCD, and PTSD.
• Three commonly used versions of exposure therapy are – Flooding (prolonged exposure) – Graded (gradual) exposure – Systematic Desensitization (graded exposure + counter conditioning)
Flooding
A behavioral treatment that involves prolonged exposure to a feared stimulus. –The phobic is exposure to the maximum fear inducing stimuli. –In short, they are introduced to the thing or situation they are most afraid of. –Creates intense anxiety, maybe near panic at first • Types of flooding procedures: –Imaginal flooding –In vivo flooding –Virtual Reality Exposure Therapy (VRET): especially useful for simulating war zone in PTSD treatment
ImaginalFlooding Procedures
- The client visualizes the scenario in the therapist’s office.
- The key is continuous exposure to the stimulus, sometimes along with response prevention: the client should not be allowed to stop the session early, avoid thinking about the stimulus, or engage in any anxiety-reduction routines.
- Response prevention holds the clients feet to the fire so that extinction can take place.
- If the client avoids the stimuli, the phobia might incubate (get worse).
In vivo Flooding Procedures
The client experiences prolonged exposure to the actual feared event (real snakes, real elevators, real skyscrapers, etc.) • This can be highly effective (esp. for people who can’t use imagery effectively) • Practical drawbacks: some events can’t be reproduced (war zones, obsessive fear of house burning down).
Concerns about Flooding Therapy
• Flooding can be highly aversive and anxiety provoking.
– The stress involved may result in medical complications in a small number of cases (definitely get a medical exam— can the client’s heart take it?).
• The duration of each exposure should be sufficiently long (at least 30 to 45 minutes).
– Must not stop too soon, or fear might get worse.
– Incubation occurs when you a briefly exposed to the feared stimulus but not long enough for extinction to start. – Don’t end session until reported fear decreases at least slightly.
Graded Exposure
Clients are exposed to feared stimuli (in vivo or imaginal or VRET), but in small doses, beginning with mildly disturbing stimuli and working up to the most feared stimuli.
• If a client is afraid of heights, flooding would involve taking the client directly to the 10th floor of a building.
• With graded exposure, you would start at the second floor and wait for fear to extinguish; then move to the third and wait for extinction; and so on.
Systematic Desensitization
A graded exposure treatment that also uses a procedure called counter-conditioning.
• Counter-conditioning means trying to create a positive association with the formerly feared stimulus.
• When you present the feared stimulus, you also try to induce a positive emotional reaction:
– This usually takes the form of relaxation techniques (progressive muscle relaxation, deep breathing, happy imagery, etc.)
– Can also use humor, comfort foods, massage
Systematic Desensitization
Mary Cover Jones, a student of Watson’s, was the creator of systematic desensitization (though she did not call it that).
In 1950s, Joseph Wolpe independently discovered this method (and gave it it’s modern name).
• Whereas Jones used in vivo desensitization,Wolpe preferred imaginal desensitization.
Famous case: Peter, a 3 yr. old boy with a rabbit phobia (1924)
Gradually exposed Peter to a rabbit, starting across the room, moving closer a step at a time (stopping when Peter was distressed, continuing when he calmed down).
– Throughout the graded exposure, Peter was fed crackers and milk, his favorites (counter-conditioning)
Wolpe’s Treatment Procedure
- Training person in relaxation.
- Creation of a hierarchy of imaginary scenes that elicit progressively intense levels of fear.
– Example: fear of public speaking
– Being asked to give a talk; writing a speech; sitting in an auditorium before your talk; approaching the podium; standing at the podium, holding your notes, etc. - Pairing of each item in the hierarchy (starting with the least feared scene) with relaxation.
- Don’t move to the next scene until the fear is gone.
Aversion Therapy
- Some behavioral problems stem from events being overly enticing rather unpleasant.
- Aversion therapy reduces the attractiveness of stimulus by associating it with an unpleasant stimulus.
- Aversion therapy relies on counter-conditioning, i.e., a stimulus that was formerly associated with positive stimuli is now paired with aversive stimuli
Aversion Therapy
Examples of undesired attractions or positive emotional reactions that have been treated with aversion therapy:
–Alcohol and other drugs, including tobacco
–Foods (e.g., “chocolate addiction”)
–Paint eating
–Nail biting
–Gambling
–Unwanted sexual attractions (fetishes, pedophilia)
Aversion Therapy 2
• Unpleasant sensations presented in many forms:
• Electrical: mild electrical shocks • Olfactory: smells (e.g., feces, ammonia)
• Chemical: Use of emetics(nausea-inducing drugs)
• Many prescription emetics used medically to induce vomiting after poisoning, overdose, etc.
• Homemade: Salt water, mustard water
• Antabuse is currently popular in alcoholism treatment. It interacts with alcohol to produces anxiety, headache, and nausea within 1015 minutes after ingestion (clip)
. • Smoking and alcohol can simply be applied in such great quantities that nausea is induced (nicotine clip: King of the Hill)
• Physical: elastic straps, rubber bands for pain
. • Humiliation
What works best?
aversion
• Nausea-inducing stimuli seem to be generally more effective than other stimuli in aversive conditioning. • Seems we are more innately likely to quickly associate to potentially deadly ingestion. –Single-pairing food aversions greatly enhance survival.
Covert Sensitization
- Aversion therapy carried out with the use of imaginal unpleasant stimuli rather than real stimuli.
- Example: – A person addicted to smoking might imagine experiencing extreme illness and vomiting each time she tries to smoke.
- This therapy is dependent on the client’s ability to visualize images clearly and to experience strong negative feelings in response to these images.
- Therapists have validated story protocols to help clients imagine fear and/or nausea-inducing stimuli.
