Classical conditioning

Question 1

What are 2 variations on basic classical conditioning?

Answer 1

A CR without a CS-US pairing
• Higher-Order Conditioning
― Also known as second-order conditioning
• Sensory Pre-Conditioning

Irrespective of the order of the training phases– both CSs can produce the CR

Question 2

What is higher-order conditioning and its limitations??

Answer 2

• Higher-order or second-order conditioning refers to conditioned responses that involve neutral stimuli (i.e., stimuli that are not directly threatening or rewarding).
• The conditioned response is established as a result of a pairing of a neutral stimulus (NS) with a conditioned stimulus (CS)

• The CR to CS2 is weaker than to CS1
― ~ 50% as strong.
• Higher-order conditioning is difficult to accomplish because conditioned inhibition also arises
― More pairings result in inhibition

Question 3

What is sensory pre-conditioning and its limitations (3)?

Answer 3

A conditioned response (CR) to an untrained stimulus can even occur when the association between the conditioned stimulus (CS1) and the second neutral stimulus (NS2) is established BEFORE the first-order conditioned response is learned

To get the strongest CR:
• Timing is important – first CS must precede second CS
• Needs to be a contingency (one predicts the other)
• Can only do a few CS-CS pairings to prevent learned
irrelevance

Question 4

What are the 3 limitations to classical conditioning?

Answer 4

• Overshadowing
• Blocking
• Latent inhibition

Question 5

What is overshadowing?

Answer 5

Start with 2 neutral stim but one is much more salient thant the other and pair them with food and causes CR
When show the compound CS, it causes CR
If present salient CS, causes CR
If present less salient CS, theres no CR

Question 6

What is blocking?

Answer 6

Conditioning fails to develop if the individual does not register that any new (predictive) information is present…
If an existing, learned association appears to provide all the information needed to predict the occurrence of the US, this existing association will serve to block the learner from developing a new association

Phase 1: Train Light CS
Phase 2: Train Light CS in compound with neutral (but equally salient) Metronome CS
Phase 3: Test elements of compound individually: Pre-trained Light Blocks conditioning to Metronome
From the learner’s perspective, there is no new info about when US will appear, so no need to learn anything

Question 7

What is latent inhibition?

Answer 7

There’s a preexisting exp with a stim inhibits the formation of new associations
Metronome doesnt cause CR bc the prior exp with the metronome without it being associated with food inhibits the association between the metronome and food (have to unlearn that metronome doesnt mean food in order to be able to associate metronome with food)
Familiar stimuli are more difficult to condition as CSs than are novel stimuli!

Question 8

What are 4 determinants of classicalconditioning?

Answer 8

1. Intensity of Unconditioned Stimuli (US)
2. Excitatory Vs. Inhibitory Conditioned Stimuli
3. Time Relationships between Stimuli
   ― Simultaneous conditioning
   ― Delayed conditioning
   ― Trace conditioning
   ― Backward Conditioning
4. Acquisition –> Extinction –> spontaneous recovery

Question 9

How does the intensity of the stimulus affect classical conditioning?

Answer 9

• Stimulus intensity influences the course of both appetitive and aversive classical conditioning
• More intense Conditioned Stimuli (CS) are more effective in accelerating the acquisition of a CR
― i.e. fewer trial needed à CR
• More intense Unconditioned Stimuli (US) are especially powerful
― Extremely intense aversive US can produce PTSD

Question 10

How do excitatory vs inhibitory stimuli affect classical conditioning?

Answer 10

• To make our environment more predictable we search for relationships between stimuli.
• Some stimuli are predictive of the occurrence of a stimulus and some are predictive of it’s absence.
• Both stimuli are just as important to learn about

Excitatory:
• When the CS predicts the occurrence of the US, it becomes an excitatory conditioned stimulus (CS+).
• CS has a positive relationship with the US
§ CS acquires an ability to “excite” the organism
§ The CS activates behavioural and neural responses related to the US in the absence of the actual presentation of the US

Inhibitory:
• When the CS predict the absence of the US, it will become a conditioned inhibitory stimulus ( CS-)
― CS has a negative relationship with the US

Question 11

What are 4 temporal relationships between pairings?

Answer 11

a) Simultaneous conditioning: CS and US are presented and
terminated together.
b) Delayed conditioning: CS is presented alone for a while, then the US is presented and the CS & US typically terminate together. This is most effective way!
c) Trace conditioning: CS begins and ends before US is presented.
d) Backward conditioning: CS is presented after US is terminated

Question 12

What is simultaneous conditioning?

Answer 12

• Simultaneous conditioning (CS and US presented at same time)
― Much weaker conditioning
― May be product of distraction of US
― If CS not before US, how can it serve as a signal?

Question 13

What is trace conditioning?

Answer 13

• Trace conditioning (CS and US separated by longer time interval in which neither stimulus is present)
― “Memory trace”- requires memory
― As CS-US interval increase, so does the decline in level of conditioning

Question 14

What is delayed conditioning?

Answer 14

• Delayed conditioning is the most effective (fastest) way of
producing a strong conditioned response!
• But the optimal delay between the onset of CS and the onset of US is very short
― Typically ~0.5 – 1.0 sec.
― As the interval increases, CR usually weakens.
― When this gap is more than several seconds, no learning is achieved. (taste aversions are an exception!)

Short delayed conditioning is the most effective because Its a good sign that a reward is coming and says when its coming

Question 15

What happens when there is a long delay?

Answer 15

― Onset of CS precedes US by at least several seconds
― CS continues until US presented
― Like Trace, CS-US interval impacts conditioning, but not as severe
― Pavlov’s dogs
§ 10 second Tone (CS) – Food (US) delay
§ 1st salivated as soon a tone presented
§ Over time, dogs began to estimate delay. Salivary response only occurs after 8-9 seconds.
§ Compound stimulus: Onset of Tone + delay

Question 16

What is backward conditioning?

Answer 16

• Backward conditioning (CS presented after US)
― Level of conditioning markedly lower
― Order is important
― Predictiveness principle: The onset of CS signals a time in which the US will be absent

Question 17

What is extinction?

Answer 17

• Extinction is a method for eliminating a conditioned response
• Extinction paradigm:
― Repeatedly present the conditioned stimulus (CS) alone (without the US)
• With repeated exposure to the CS, it stops being a predictor of the US and the CR decreases and eventually stops
• Systematic Desensitisation/Exposure therapy uses an extinction-like paradigm
― Represents gradual way to expose CS
― Highly effective treatment for phobias and PTSD
• Extinction: Repetition of CS without US reduces CR.
• Spontaneous Recovery: After extinction, if there is a delay, the CS will often produce a weak CR.

Question 18

How do we know that learning is not erased after extinction? (3)

Answer 18

• Occurs gradually
• After extinction, there is no CR.
• But CS-US association is not erased!
• Three Phenomena illustrate this point:
1. Spontaneous recovery
2. Disinhibition
3. Rapid Reacquisition; once extinguished, need fewer trials to get back to previous CR
If all the learning had been completely extinguished, reacquisition should take just as long the second time as the first time

Question 19

What determines the rate of extinction?

Answer 19

• The number of trials does not determine rate of extinction
• The total duration of exposure to the CS determines how fast the CR is extinguished
• The impact of the duration, rather than the number of times an individual is exposed to the CS, is an important consideration for exposure therapy

Question 20

What are 5 inhibition phenomena?

Answer 20

• Latent inhibition Pre-exposure to the CS (without the US) inhibits later learning
• External inhibition – presence of a novel cue during conditioning inhibits the CR
• Conditioned Inhibition – a CS that predicts the absence of the US
• Inhibition of Delay – the CR is withheld until an appropriate time
• Disinhibition – removal of inhibition by the presentation of a novel stimulus

Question 21

What is conditioned inhibition?

Answer 21

• Conditioning in which a neutral stimulus is associated with the presentation of a US is known as excitatory conditioning.
• The result is that the CS (now called an excitatory CS or CS+) acquires the capacity to regularly elicit a CR.
• Conditioning in which the neutral stimulus is associated with the absence or removal of a US is known as inhibitory conditioning.
• The result is that the CS (now called an inhibitory CS, conditioned inhibitor or CS-) comes to inhibit the occurrence of a CR.
• Conditioned inhibition has an important prerequisite: for the absence of a US to be a significant event, the US has to occur periodically in the situation
• There are many signals for the absence of events in our daily lives: ― Signs such as ‘Closed’, ‘Out of Order’ and ‘No Entry’ are of this type.
• However, these signs provide meaningful information and influence what we do only if they indicate the absence of something we otherwise expect to see

Question 22

What is learned in conditioned inhibition?

Answer 22

• There are two ways to interpret the inhibition results:

1. The light has become a conditioned inhibitor (i.e., its presence causes a reduction in the size of the CR)
2. The animal has learned nothing about the light on its own, and only about the compound CS as a unit

To examine whether the light has developed inhibitory properties itself, other tests were developed…

Summation: a conditioned inhibitor is presented in compound with a separately trained excitatory conditioned stimulus (CS) – that is, one that evokes a conditioned response. If the stimulus functions as a conditioned inhibitor, it should decrease conditioned responding evoked by the separately trained excitor relative to controls that receive the excitatory CS alone

Retardation of acquisition test: a stimulus is first trained as a conditioned inhibitor. Once complete, the stimulus is then repeatedly paired with the unconditioned stimulus (US). If the stimulus functions as a conditioned inhibitor, acquisition of an excitatory conditioned response should be impaired (retarded) relative to controls.

Question 23

What is inhibition of delay?

Answer 23

― Pavlov’s dogs
§ 10 second Tone (CS) – Food (US) delay
§ At first, they salivated as soon a tone presented
§ Over time, dogs began to estimate delay. Salivary response only occurs after 8-9 seconds.
§ Compound stimulus: Onset of Tone + delay i.e., delay becomes part of the CS

Question 24

What is disinhibition?

Answer 24

• Disinhibition is the removal of inhibition
― the CR increases in strength
• Disinhibition can occur during extinction
―Presentation of a novel stimulus interrupts extinction
―E.g., disinhibition of the inhibition of delay occurred with a novel stimulus.