Transcript Some Practical Applications of Classical Conditioning

Some Practical Applications of
Classical Conditioning
Understanding Phobias
• John B. Watson was the first person to study
human emotions systematically
• Because of his and subsequent research, we
now recognize that most of our emotional
reactions are learned and they are learned
mainly through classical conditioning
• Watson & Rayner (1920 & 1921) began their
research by testing a number of infants to see
their reactions to fire, dogs, cats, laboratory
rats, and other stimuli thought to be innately
frightening; none of these were
Understanding Phobias
• Watson & Rayner (1920) found that a loud
noise did elicit an innate fear reaction (crying
and other fear-like responses)
• They then did the famous Little Albert study
where they paired a white lab rat (CS) with
striking a steel bar with a hammer behind
Albert’s head (US)
• Little Albert began to show fear (crying and
crawling away = CR) to the white lab rat
fairly quickly
“Little Albert” Experiment
Factors in Phobic Conditioning
• Observational Learning-acquiring a fear CR through
observing someone else showing fear to the CS
• Temperament-an organism’s base level of
emotionality & reactivity to stimulation (poodles vs.
german shepherd dogs)
• Preparedness-the tendency to associate some CS-US
associations more readily than others
• History of Control- having some control over events
in their lives immunizes organisms against a higher
level of fear associated with strange new stimuli
Treating Phobias
• Mary Cover Jones (1924) was another of
Watson’s students
• She was the first to show that classical
conditioning could help people overcome
fears as well as acquire them
• Jones’ most famous subject was Peter, a
toddler with a fear of rabbits
• She used counterconditioning on Peter
Treating Phobias
• Counterconditioning
– One CS is presented at the same time as another
event, that elicits an incompatible response
• Jones (1924) brought a rabbit (CS that elicits
anxiety) into the same room but far away from Peter
while he was eating his cookies and milk snack (CS
that elicits good feelings)
• Jones did this each day and gradually brought the
rabbit closer and closer until there was no fear to the
rabbit (eventually the rabbit was put into his lap!)
Treating Phobias
Systematic Desensitization (Joseph Wolpe,1958)
– Train person to fall into deep relaxation
(meditation)
– Create hierarchy of fear eliciting stimuli
• from least to most strong example of stimulus
– Gradually (from least to most) pair each item of
hierarchy with relaxation
• without producing fear (because of deep relaxation)
• combines counterconditioning, generalization, and
extinction
Treating Phobias
• Paul (1969) conducted a study with students that had
severe anxieties about public speaking
• He had 3 treatment groups
• Reexamined the students 2 years later and found the
following amounts of improvement above
pretreatment levels:
– 85% in the systematic desensitization group
– 50% in the insight-oriented psychotherapy group (focuses
on identifying the cause of the anxiety)
– 22% in the untreated control group
Treating Phobias
• Davison (1968) conducted a study with students that
had an intense fear of snakes
• He gave them a 13-step test to assess their initial
fear (using a real snake in a jar, up to touching one)
• Groups:
– CS-UCS group: systematic desensitization
– CS2-UCS group: imagined childhood disturbances +
relaxation
– CS-noUS group: imagined snakes but no relaxation
– No treatment: control group
• The only group to show improvement (an average of
5 steps closer to live snake) was the systematic
desensitization group
More Phobia Treatments
• Flooding
– prolonged exposure to the feared stimulus
– provides maximal opportunity for the fear
response to extinguish
– Problem: may involve too much stress for the
phobic individual
Flooding to Treat Phobias
• Rothbaum (1995) was the first to use virtual reality
technology in an experiment to provide exposure
to the feared stimulus
• She had people with a fear of heights wear a
helmet that presented computer simulated scenes:
– walking on foot bridges & outdoor balconies, and riding
up a glass elevator (up to 50 floors high)
• Resulted in a marked reduction in fear of heights
(but equal to subjects exposed to the actual
heights)
Eliminating Problem Behaviors
• Aversion Therapy
– pair the problem behavior with an aversive
stimulus
– as an association forms the attractiveness of the
problem behavior is reduced
• Some pairings of CS and US are not as
effective as others (preparedness)
– Drinking alcohol paired with electric shock
Counteracting Conditioned Taste
Aversion
• Broberg & Bernstein (1987) tried a procedure with
children being treated with chemotherapy that
Revusky (1971) had found effective with rats
• They gave the children a distinctive-flavored
Lifesaver candy (CS) between their evening meal
and the chemo session (US) and found that 12 of
15 children ate the food at the meal again later
• On another occasion the same children were not
given the Lifesaver candy between the evening
meal and chemotherapy, and they found that only 6
of the 15 children would eat that meal again
Advertising
• Pair products with stimuli that elicit positive
emotions (e.g., a form of second-order
conditioning)
• Stuart et al. (1987) showed a series of slides to
college students that contained neutral scenes,
pleasant scenes, and various products
– Experimental group = Brand L toothpaste was presented
several times and always followed by pleasant scenes
– Control group = Brand L toothpaste was always followed
by neutral scenes
• Afterwards she found that Experimental students
rated Brand L significantly more positively than the
Control group did
Conditioned Allergic Reactions
• People may develop allergies through conditioning
• Pair a neutral stimulus (CS=sight of flowers) with
an allergic reaction (US=pollen which produces a
UR=allergic response)
• Person will begin releasing histamines
(CR=allergic response) at the sight of the flower
(not just to the pollen)
Conditioned Immune Responses
Conditioned immunosuppression
– Ader & Cohen (1975) study with rats
– CS (Sweet water)→US (drug) = UR
(immunosuppression – immune system produces
less antibodies)
– Tested by injecting foreign cells, then giving half
the rats the CS (sweet water) and half the rats
plain water (no CS)
– Rats given the CS showed a CR of
immunosuppression resulting in fewer antibodies
to the foreign cells than rats given plain water
Conditioned Immunosuppression as
a Treatment for Lupus
• Olness & Ader (1992) treated an 11-year old girl
with severe lupus
• Standard treatment is cyclophosphamide (an
immunosuppressant drug), once per month for 1
year
• They gave the girl a compound CS (taste of cod
liver oil & smell of rose) followed by
cyclophosphamide on 6 occasions, and on
alternating months gave her just the CS
• She showed a significant reduction in symptoms
and still looked good 5 years later
Conditioned Immune Responses
• Conditioned Enhancement of the Immune
System
– Kirschbaum et al. (1994)
– CS (sweet sherbet) → US (adrenaline) = UR
(enhanced natural killer cell activity)
– Following this pairing in human subjects, the CS
elicited a CR (increased natural killer cell
activity)
• Enhancement of the immune system is harder
to get; results are inconsistent