Lecture 17: Aversive Control - Avoidance and Punishment Flashcards
What are 2 types of aversion learning?
- Negative reinforcement
- Positive punishment
What is negative reinforcement?
- Individual produces response to prevent an aversive stimulus from occurring
- Negative contingency; active avoidance
- Increases the occurrence of instrumental behaviour
- Escape and avoidance
What is positive punishment?
- Response produces the aversive outcome
- Positive contingency; passive avoidance
- Suppresses instrumental behaviour
What kind of experiment did Vladmir Bechterev do?
- Tone (CS) followed by shock (US) through metal plate
- Participants learned to remove finger (CR) when tone presented to avoid getting shocked
- Tone acted as a warning signal
- Originally thought to integrate classical conditioning
- Instrumental avoidance: Subjects controlled whether or not they received US
In avoidance procedures, what are the CS and US also known as?
CS - Warning signal
US - Aversive stimulus
What did Brogden, Lipman and Culler find?
- Examined difference b/n classical conditioning and instrumental avoidance procedures
- Classical = US followed tone
- Avoidance = US followed tone unless rats ran in wheel
- Avoidance is learning more efficiently with instrumental conditioning
What are discriminated avoidance procedures?
- Examine relation of warning signal to US and instrumental response
- Consequence depends on what animal does
What are 2 features of discriminated avoidance procedures?
- Discrete trial initiated by warning stimulus (CS)
- What happens after CS depends upon what the animal does:
Successful avoidance = Target response in time (CS is terminated, US not presented)
Escape trial = Target response not in time (CS persists, US presented until response)
Describe the two forms of shuttle avoidance?
One-way - Trial begins on one side (shock side) - CS/US are presented - Animal avoids/escapes to safe side Two-way - CS presented on either side - Opportunity to avoid by jumping to opposite end - More difficult to learn - Safety zones are interchangeable
How can the absence of something provide reinforcement?
- Once avoidance is learned, the outcome does not occur
- Looks like extinction (behaviour not reinforced by shock anymore)
What is the Two-Factor Theory?
Factor 1 - Pavlovian fear conditioning Shock (US) -> Fear (UR) Tone (CS) - Shock (US) Tone (CS) -> Fear (CR) - Organism fails to make target avoidance response
Factor 2 - Instrumental reinforcement through fear reduction (negative reinforcement)
Avoidance response -> Termination of tone (CS) = Reduction of fear (CR)
What motivates responding?
- Negative reinforcement
- Escape from conditioned fear
What did Mowrer discover? Why did he look at this?
- Two-Factor Theory
- Not much is known about what individuals experience in avoidance learning to maintain response
What does the Two Process Theory suggest?
- Classical conditioning of fear and instrumental reinforcement through fear reduction are intermixed
- Can animals learn to escape conditioned fear?
What is the Escape from fear procedure?
- EFF procedures demonstrate classical and instrumental can distinctly make contributions to avoidance learning
Describe the process of the EFF procedure
- Delayed conditioning/Pavlovian group: CS -> US
- Simultaneous conditioning/Instrumental group: CS + US
- Test: shuttle box barrier moved; rats placed on shock side and CS was activated; Moving to opposite side terminated US
- Results: Both groups showed latencies to escape fear stimulus; demonstrate EFF learning
What did Brown and Jacobs Acquired Drive experiment look at?
- Can escape from fear serve as a reinforcer
- EFF confirms that terminating a feared stimulus is reinforcing
What did the Acquired Drive experiment do and what did it discover?
Phase 1: Pavlovian Light/tone (CS) -> Shock (US) Phase 2: Instrumental Light/tone (CS) -> No shock (US) Rat could terminate CS by moving to safety side - Animals do learn to escape CS - Supports 2-process theory of avoidance
Is fear correlated with avoidance?
- If fear motivates and reinforces avoidance, then conditioning of fear and avoidance behaviour should be highly correlated
- Fear is not always positively correlated with avoidance
- Animals are less fearful as they become more proficient in performing avoidance response
What did Lovibond and Colleagues find?
- Students received Pavlovian or instrumental conditioning with shock
- Instrumental group became unafraid of US; learned to prevent shock
- If avoidance response was bock, fear returned
Can we extinguish avoidance behaviour? Who examined this?
- Solomon, Kamin, and Wynne
- Dog avoided shock 650 straight trials after escaping a few
- How is this extinguished?
What is response blocking and flooding?
- Participants are prevented from making instrumental avoidance response to the CS
- The US is omitted (extinction)
- By blocking avoidance response, participants are exposed to CS for a long period of time (FLOODING)
What is nondiscriminated/free operant avoidance?
- Can individuals learn an avoidance response if no external warning stimulus in the situation?
- Procedure does NOT involve a warning stimulus
- Shock scheduled to occur periodically
- Avoidance behaviour reinforced by safety period
- Performance of behaviour before shock-free period is complete restarts safety period
What is the S-S interval in nondiscriminated avoidance?
- Shock-shock
- Interval b/n shocks
- Failure to respond
What is the R-S interval in nondiscriminated avoidance?
- Response-shock
- Period of safety created by each performance of target behaviour
- Typically longer than S-S
What is the main principle for free-operant avoidance?
- By responding before the end of each R-S interval, the individual can always reset the R-S interval and thereby prolong its period of safety indefinitely
What are some alternative accounts of avoidance behaviour?
- Positive reinforcement through conditioned inhibition of fear or conditioned safety signals
- Reinforcement of avoidance through reduction of aversive US frequency
- Avoidance and species-specific defence reactions (SSDRs)
How does positive reinforcement impact avoidance behaviour?
- Avoidance response -> safety period + feedback stimulus
- Feedback stimulus = safety signal; reinforces avoidance behaviour
Describe reinforcement of avoidance through reduction of aversive US frequency?
- Rats will press lever to reduce the frequency of shock from 6/min to 3/min
What are species-specific defence reactions?
- Focuses on what controls organism’s behaviour (natural behaviours) during early stages of avoidance training
- Innate responses; adaptive behaviours that promote survival and wellbeing (ex. flight, freezing, burying, etc)
- Environment creates context for innate responses
What did Skinner/Thorndike find about the effectiveness of punishment?
- Punishment was not very effective; temporary impact
- Punishment is effective if the correct conditions are met (ex. speeding ticket vs. child sticks fork in electric socket)
Describe the experimental analysis of punishment
- Aversive stimulus (US) presented after a target instrumental response
- Target response should decrease
- Preliminary phase: target response is reinforced
- Punishment is introduced once target response is conditioned
- Positive reinforcement vs. punishment
What are 3 characteristics of the method of introduction of aversive stimuli?
- Types of stimuli (positive vs. negative)
- Intensity of stimuli (More intense, longer shock vs. less intense, short shock)
- Introduction of stimuli (abrupt vs. escalation of punishment)
What is delay of aversive stimuli?
- Interval b/n target response and aversive stimulus
- Increased delay = decreased suppression of behaviour
What effect does the schedule have on aversive conditioning?
- Intermittent delivery of punishment
- Degree of response suppression produced by punishment depends on proportion of responses punished
- Short delay is more effective
What do the effects of punishment depend on?
- Reinforcer that maintains target response
- drug addiction; drug
seeking persists despite
adverse effects - Individual differences
- Only a subset who try
drugs of abuse develop
SUD (may be resistant to
punishment)
What is compulsivity in relation to punishment?
- Compulsive cocaine seeking emerges in a vulnerable subpopulation of animals
- Vulnerable subgroup had marked reduction in forebrain serotonin; related to inability to abstain from responding for cocaine despite punishment
- Treatment with Citalopram (SSRI) ameliorated compulsive drug seeking
What helps punishment be more effective?
- Availability of alternative sources of positive reinforcement
- Discriminative punishment
- Punishment as a signal for the availability of positive reinforcement
Describe how positive reinforcement helps punishment be more effective? Who discovered this?
- Punishment is more effective if subject is offered an alternative response to punished response
- Herman and Azrin
What is the significance of discriminative punishment?
- Responding is punished in presence of discriminative stimulus, not punished in its absence
- Suppressive effects of punishment limited to presence of discriminative stimulus
What is the significance of punishment being a signal for the availability of positive reinforcement?
- Positive reinforcement is available only when instrumental response is also punished
- Punishment = discriminative stimulus for positive reinforcement
What is the conditioned emotional response theory?
CS - Shock (US) -> Suppression of CR
What is avoidance theory?
- Punishment as a form of avoidance behaviour
- Explains acquisition of incompatible avoidance responses
- Stimuli acquire aversive properties with punishment
What is the Negative Law of Effect?
- Thorndike
- If a behaviour is followed by punishment, the likelihood of the behaviour occurring again decreases
- ‘Losing a penny is 3x more punishing than earning that same penny is reinforcing’
