FINAL REVIEW Flashcards
Habituation
A DECREASE in response to an elicit stimulus with repeated presentations of that stimulus
Sensitization
A INCREASE in response to an elicit stimulus with repeated presentations of that stimulus
Conditioned Stimulus
Does NOT elicit response initially
Unconditioned Stimulus
Biologically significant stimulus that naturally elicits a response.
Unconditioned Response
Response with respect to the Unconditioned Stimulus (US).
Conditioned Response
Response with respect to the Conditioned Stimulus (CS).
Suppression Ratio
SR= CS Responding/ (CS Responding) + (Pre CS Responding)
If the suppression ratio is near 0.5, not much suppression occurred (crappy learning)
If the suppression ratio is near 0, a lot of suppression occurred (great learning)
Stimulus-Response
The CS activates the CR directly.
Stimulus-Stimulus
The CS activates a representation of the US, which activates the CR.
Contiguity
The CS and US become associated if they occur close together in time.
Contingency
Refers to the PREDICTIVE RELATIONSHIP between the CS and US.
Fixed Ratio
Every “x” response is reinforced
Fixed Interval
Response is reinforced only after a certain time has passed.
Variable Ratio
Response is reinforced after a fixed AVERAGE number of trials.
Variable Interval
Response is reinforced after an AVERAGE amount of time has passed.
3 Experiments that prove Extinction does not erase Acquisition.
Spontaneous Recovery
Context Renewal
Reinstatement
3 Mechanisms of PREE
Discrimination Hypothesis-
- After CRF, non RF is much easily detected.
- After PRF, non RF is harder to detect.
Frustration Theory-
- After non reward, subject is frustrated and expects NOT to be rewarded on the next trial.
- Animal learns to respond even when frustrated.
Sequential Theory -
- When an animal is rewarded on a trial after after one or more non rewarded trial. Animal remembers not being rewarded on previous trials.
- Animal learns to respond in the presence of the memory of non rewarded trials.
Avoidance
A warning stimulus (e.g. tone, light) signals an aversive stimulus (e.g. shock)
-if the required response is made during the warning stimulus, before the aversive stimulus occurs, the subject avoids the shock
Escape
If the response is not made during the warning stimulus, the aversive stimulus occurs, and terminates only when the required response is made (i.e. escape)
Two Process Theory of Avoidance
The absence of the aversive stimulus is obviously the reason for the avoidance behavior.
Classical Conditioning - CS –> US is learned
- this is learned during the escape trial.
- over time, the CS (tone) elicits fear.
- fear is an unpleasant emotion, thus provides the motivation for the second process.
Instrumental Conditioning -
- by reducing or eliminating the unsettling state of fear elicited by CS (tone) ; preventing shock is just the by product of the reduction in fear.
Support for the Two Process Theory: Acquired Drive Experiments
In a typical avoidance procedure, classical conditioning of fear and instrumental reinforcement through fear reduction occur intermixed in a series of trials.
- if this is correct, then separating the processes should still lead to successful learning.
Acquired Drive Experiments
Acquired Drive Experiments
Two phases
Phase 1: Classical conditioning to acquire fear of CS
Phase 2: Escape training with the CS. (US no longer present)
Referred to acquired drive experiments because fear was learned and not something innate (e.g., hunger or thirst)
Questioning the Two Process Theory: Kamin, Brimer, Black (1963)
If fear motivates and reinforces avoidance responding, then the conditioning of fear and the conditioning of instrumental avoidance behavior should be highly correlated
However, the level of fear is not always positively correlated with avoidance.
Animal is often becomes less fearful as they become more proficient in performing the avoidance response.
Rats were initially trained to bar press for food.
Then trained to avoid shock in response to a tone
Avoidance training continued for separate groups until they avoided the shock on 1, 3, 9, or 27 consecutive trials
The animals were then returned to the skinner box for bar pressing
The CS that had been used in the shuttle box was periodically presented to see how much suppression of bar pressing it would produce.
Effectiveness of Punishment
The aversive outcome stimulus weakens the likelihood that the response will be made.
Thorndike and Skinner claimed punishment was not very effective in suppressing behaviour
When is Punishment effective?
When the response to be punished is:
Not being reinforced, or motivated
When there is an alternative response to the punished response to acquire reinforcer
Problems with Punishment
Undesirable emotional reactions to the situation or person associated with punishment
Difficulties in applying punishment systematically
Imitation of aggressive behaviour involved in punishment
Punishment in the Laboratory
Phase 1
Rats were reinforced with food on a VI schedule
Phase 2
Extinction for 120 minutes on two successive days
Group 1: During first 10 min of extinction on Day 1; rats was punished for each bar press (paw was slapped)
Group 2: Control group was not punished
