learning Flashcards
associative vs non-associative learning
Associative Learning: any learning process in which a new response become associated with a particular stimulus
* Classical
* Operant
Non- associative Learning: Learning that results in a change in the frequency or amplitude of behaviour/ response after repeated exposures to a single stimulus
* Sensitisation
* Habituation
Associative learning stages
Acquisition Phase:
* During the CS-US pairings lead to increased learning. As a result, the CS can produce the CR.
Extinction:
* If the CS is presented without the US, eventually the CR is eliminated. This process is called extinction.
Spontaneous:
* Later, if the CS is presented alone, it will produce a weak CR, known as spontaneous recover
Non Response:
* This CR gets weaker with every spontaneous recovery and will eventually be extinguished if the CS is continually presented without the US.
Stimulus Substitution Theory:
- Pavlov thought that the CS became as substitute for the US
- Innate US-UR reflex pathway
- CS substitutes for the US in evoking the same response
- CR and UR produce by the same neural region
jenkins and moore pigenon respone to light and different stimulus
Sign tracking vs Goal tracking
- Sign trackers direct their behaviour at the CS even at the expense of the US.
- only sign trackers ascribe incentives to the cue (CS)
- Goal trackers behaviour is directed to the US .
Preparatory Response Theory
- Kimble’s (1961,1967) theory proposed that the CR is a response that serves to prepare the organism for the upcoming US
generalisation and dicrimination
- Stimuli Generalisation A tendency to respond to stimuli that are similar, but not identical, a conditioned stimulus
- Transfer of training: Being able to apply knowledge gained in one situation to that of a similar one
- Stimulus Discrimination: The learned ability to respond differently to similar stimuli – pigeon picking the better painting
high order conditioning
(cs-cu > cs -cs)
High – Order condition:
* CS leading to CR without presenting the US
High – order or second-order conditioning refers to conditioned responses that involve neutral stimuli (stimuli that are not directly threatening or rewarding)
Limitation of High-order Conditioning
The CR to CS is weaker than to CS-2
* 50% as strong as initial response
Sensory Preconditioning
(cs-cs > cs -us)
In second-order conditioning, one CS is capable of becoming associated with another CS.
Overshadowing
- Condition with a compound CS, i.e simultaneously present
- Test elements of compound CS: Salient elements ‘bright Light” overshadows less salient metronome. This leads to no conditioned response to the metronome
Blocking
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.
- From the learners perspective, there is no new information about when US will appear, so no need to learn anything.
Latent Inhibition
- The dog has experience with the stimuli (e.g. with a metronome)
- Familiar stimuli are more difficult than are novel stimuli
Temporal Relationships Between Pairings
Trace interval: time between cs and us
long delay;
* Onset of CS precedes US by at least serval seconds
* CS continues until US is presents
* Pavlov’s dogs: when they got use to the 10 second stimuli their response would only happen in the last 8-9 seconds.
Backward Conditioning
(CS presented after US)
* Level of conditioning markedly lower
* Order is important Predictive principle: The onset of CS signals a time in which the US will be absent
spontaneous recovery
after a period of time has passed the CS with create a weak response.
The Rescorla- Wagner Model of Classical Conditioning
Contingency: refers to the predictability of the occurrence of one stimulus from the presence of another
- Increasing the delay between the CS and US results in the CS becoming less useful as a predictor of the US
- Contingency is the probabilistic relationship with the US given that a CS has occurred
The probability (p) of a US
The probability (p) of
occurring given that (/) a CS is presented
* is greater than (>)*
the probabiltity of
a US given that (/) NO CS is present
Contingency theory –
conditioned response develops when the conditioned stimulus is able to predict the occurrence of the unconditioned stimulus
Negative Contingency Between CS and US
If the CS reliably predicts the absence of the US, then the CS and US are negatively correlated
Blocking: Rescorla-Wagner
When two CSs are presented, the subject’s expectation is based on the total expectation of both the CSs. When they are not presented together the response is not the same strength.
Shaping or successive approximates:
Specifically, when using a shaping technique, each approximate desired behaviour that is demonstrated is reinforced, while behaviours that are not approximation of the desired behaviour are not reinforced.
Fixed ratio:
- Behaviour reinforced (100/1, 50/1)
- Response Rate (higher ratio = faster responding)
- Resistant to extinction: Low
Behaviour Patterns in Fixed Ratio Schedules - Post reinforcement Pause: Brief pause before recommencing the behaviour
- Ratio run: When the response increases closer to the reward
- Goal gradient: as you get closer to the reward the task feels easier and increases response through knowing the reward is near.
variable ration
- Behaviour/ reinforcement:
Random/unpredictable number of responses between reinforcements - Response rate: Fast
- Behaviour: Work hard and at steady rate
- Resistance to extinction: High
This is because it’s harder to decern if there is still a chance of getting a reward
Fixed interval Schedule
Variable- interval Schedule
- Response rate: Slow
- Behaviour: Work at a steady rate
- Resistance to extinction: High
Fixed interval Schedule
- Response: Scalloped
- Behaviour: high before reinforcement/ long pause after
- Lowest rate of responding
- Extinction resistances: Low
