Classical Conditioning
• Basic form of learning
• Not the most sophisticated, but important
• Eysenck’s patient
• Pavlov: His background and discovery
• Background info!
Background info
• In any animal species, there are “built-in”
innate (inborn) responses to particular
stimuli
• Unlearned reflexes or emotional responses
• Examples:
• Food in mammal’s mouth elicits salivation
•
[describe demo with puff of air]
Gust of wind directed at
eye eyeblink
• Sudden loud noise startle response!
• In infants, almost always evokes strong fear
response, as well
• To distinguish these innate stimulus-response
connections from learned ones, Pavlov gave them
special names:
e.g.
FOOD IN MOUTH
SALIVATION
Unconditioned Stimulus (UCS) Unconditioned Response (UCR)
UNEXPECTED LOUD NOISE FEAR
Unconditioned Stimulus (UCS)
Unconditioned Response
(UCR)
• Most stimuli do not trigger off reflexive,
or any predictable response
• e.g., dog’s response to musical tone
• These are called Neutral Stimuli (NS)
• Pavlov believed that under certain
circumstances, NS could acquire ability
to reliably elicit a specific response
• Came about through process of learning!
set out to study!became known as
Classical Conditioning
Basic Classical Conditioning model
Repeat several times
RESULT:
Conditioning
has occurred
Bell (CS)
Real-life example
•
[incident at International House cafeteria]
UCS
toxin in shrimp
UCR
regurgitation
NS
sight
smell OF SHRIMP
taste
As result:
Smell, sight (taste)
of shrimp became CS
CR
Nausea
• Important points
1) Conditioning occurred with just
single pairing between UCS and NS
• Example of single-trial learning
• Often occurs when UCS is aversive
• = Painful, harmful, sickening
• Specialized brain mechanisms now known to be
involved (incl. amygdala and hippocampus) in
ensuring rapid learning occurs in threatening
situations
• 2) CR lasted for years [discuss my behavior]
:
Conditioned Aversive Responses (another
ex. = fear) are enduring
3) Conditioned response transferred to other
similar stimuli
• e.g., oysters, lobster
• phenomenon = Generaliztion
• E.g. Pavlov’s finding re conditioned
salivation response
Generalization: Following conditioning, stimuli
similar to CS will also elicit CR (although will
be weaker)
Adaptive value?: Ex. Of child burning himself on specific stove
Final note (about the shrimp example): Is example of
taste aversion conditioning
Can occur even if long delay between UCS and UCR
Extinction
• What if CS repeatedly encountered
without UCS ever recurring?
• E.g.
• Tone sounds Bonzo salivates (but no
food follows)
• Tone sounds Bonzo salivates (no food)
• Tone sounds Bonzo salivates (no food)
....4th time, 5th time, 6th time, 7th time!???
In fact, CR will weaken and eventually cease
= Extinction
The (in)famous case of little Albert
•
Discuss
John Watson
• Hypothesis re phobias
• The convenient subject- “Little Albert”
• Albert looking at white rat
NS
Sudden loud noise startle, fear
UCS
UCR
Since rat (NS) present when noise (UCS)
occurred
Rat became CS ( fear = CR)
• Furthermore, the fear generalized
• e.g., rabbit, other furry animals, Santa Claus beard
•
http://www.encyclopedia.com/video/Xt0ucxOrPQE-john-watson-little-albert.aspx
• What happened to Albert’s fear?
• Remained quite strong over next few weeks, although
somewhat diminished
• Did NOT fully extinguish (as textbook suggests)
• Watson then lost contact with Albert
• Watson’s prediction (1920):!
• Would Watson have been successful in
“deconditioning” the fear?
• Probably not
• Difficult problem
• Successful method not discovered until 1960s
•
Why are conditioned fears (and other
conditioned aversive responses) resistant to
extinction? -- Why do they last so long?
Two main reasons:
1) Properties of nervous system:
extinction is active process, involves inhibiting
(suppressing) the learned response (we learn not
to fear)
In case of conditioned aversive responses, stronger signal
required (than in case of other conditioned responses)
- in effect, brain “demands” more “evidence” before it will
override the response
2) We tend to avoid situations where we might
encounter the feared stimulus
by doing this, we don’t meet conditions required
for extinction to occur >>
Conditions under which extinction will occur
• The CS must be repeatedly
encountered without the UCS recurring
• In effect, one is actively learning that the
UCS-CS link no longer holds true
• But if you avoid CS, you do not
have opportunity to learn this
Treatment of phobias
Recall: For extinction of conditioned fear
response to occur
The CS must be repeatedly encountered
without the UCS recurring
Exposure therapies (based on classical
conditioning) provide conditions under
which extinction is likely to occur
• (gradual) exposure to feared object/situation
Process = deconditioning
1. Flooding
[characterize; enact balloon phobia case]
• Flooding = massive exposure to the feared CS
2. Systematic Desensitization Therapy
• More gradual, gentler
• goal is to minimize anxiety experienced by
the client (patient) during the treatment
3 Steps
1. Develop hierarchy (rank-ordered list) of
feared objects/situations (related to the
central phobia
• “What is most terrifying thing--?
• Cat on head
• Cat on lap
• ..
• ..
• ..
• Cat behind closed window
• Garfield cartoon
• Picture of cat
• ..
• Fur glove
• 2. Teach progressive relaxation therapy
•
[describe]
• Purpose to give client means of inhibiting
fear response during treatment
• Based on fundamental property of
Autonomic Nervous System (ANS)
• Fear involves arousal of one of the main
branches of the ANS = sympathetic nervous
system (“fight-flight” response)
• [snake phobia video clip]
The Autonomic Nervous System (ANS)
• 2 major branches: the Sympathetic and
the Parasympathetic
• Parasympathetic involved largely in
“maintenance” functions; e.g. digestion
• Sympathetic ~ “fight or flight” system
• Activated when we feel threatened
• Designed to mobilize the body and brain for
rapid, energetic response to crisis (real or
imagined)
• When afraid, sympathetic nervous system is
aroused
Autonomic nervous system – 2 branches
Systems push in opposite directions (= “antagonistic”)
• Activation of one tends to deactivate the other
• Arousal of the “fight-flight” system will deactivate
the parasympathetic
• But the opposite can occur as well
• I.e., turn on parasympathetic and you inhibit
sympathetic
• Recall: Sympathetic activity underlies fear
response
• Activation of parasympathetic system can calm
anxiety- this is exactly what deep muscular
relaxation does
3. Proceed with the deconditioning!.
• work through the list