L7 - The Conditions of Conditioning Flashcards
Temporal contiguity
Occurs when two stimuli are experienced close together in time and, as a result an association may be formed.
- In Pavlovian conditioning the strength of the association between the conditioned stimulus (CS) and the unconditioned stimulus (US) is largely affected bytemporal contiguity.
General Rule of temporal contiguity
The amount and speed of conditioning decreases as temporal separation of CS and US increases.
Why would taste aversion conditioning take longer than eyeblink?
The brain isn’t just mindlessly learning two things that work together, it is discounting what is biologically implausible, food takes longer to digest and for the effects to happen so there is more of a delay
Relative vs Absolute contiguity
GIbbon et al (1977)
Effect of trial spacing, how much you pair these things in time also affects how much you learn
Space trials more = more learning
Massed vs spaced learning
- cramming is bad
How to work out temporal contiguity ratio
time between trials divided by trial duration (CS-US duration)
- What is important in learning is the ratio of the inter trail interval and the time between CS US delay
- You want a very large ratio
e. g. large spacing between trials and short time between US-CS
How did rescorla make a truly random schedule?
The US occurs at random times with respect to the CS, no correlation positive or negative.
- Still contiguity but this brakes the confound of correlation in time so produced no conditioning, much better control
Overshadowing
When two or more stimuli are present, and one stimulus produces a stronger response than the other because it is more relevant or salient.
Called overshadowing as one stimulus detracts from the others learning.
Salience
how noticeable a stimulus is
Example of overshadowing
- Tone 1 predicts sucrose pellet and green light does individually
- In overshadowing condition when both are presented at the same time, when tested individually both are lower and light is particularly low
How did Mackintosh show salience impacted learning?
○ 3 conditions (light is always the same
- Light
- Light + quiet tone
- Light + loud tone
If the light is presented in isolation with the shock you learn a lot and with soft noise you do too
Key loud noise overshadows and learns less about the light
What is the range of the repression ratio?
0 repression ratio is a lot of learning, 0.5 is learning nothing at all
- 0-0.5 range
Kamin’s Blocking Effect
When pairing two USs with a CS, if one CS is already conditioned to the US this will reduce the learning for the other CS when paired all together
Blocking stimuli I pre-conditoned
How did Kamin show the blocking effect
Phase 1:
CS1 = shock lots of trials
Phase 2:
CS1 = shock
CS2 = shock
(played at the same time
With the blocked condition learning CS2 is not learnt well
Pigeons and relative contiguity
Pigeons had a CS duration of 4, 8, 16 or 32 seconds before the food would be delivered to the pigeon.
The group that had the light come on for 4 seconds learned the fastest, to associate the light with food.
Whereas the 32 second group took over 100 trials to make the association between the light and food.
However the groups that had the longer time intervals between trials learnt quicker than those that had shorter time intervals between trials
Name the 4 things that affect the strength of conditioning (all time related)
Name 4 ways of associating stimuli by manipulating spacing trails
- Delay conditioning - the CS comes on and then ends with presentation of the US; this is an excellent way to produce conditioning.
- Trace conditioning - where the CS and US are separated by a gap; can produce ok learning, but conditioning gets worse as the trace interval increases.
- Simultaneous conditioning - arrange the CS and US in time to present them both simultaneously; weak conditioning because the CS doesn’t signal the US.
- Backward conditioning - when the CS comes after the US in time; produces weak conditioning
