Chapter 10 Flashcards
What is an aversive stimulus
Unpleasant stimulus
What is avoidance
the target response prevents an aversive stimulus from occurring
What is active avoidance
Safety is achieved by doing something
What is shock-probe fear conditioning
• Animal in Skinner box • Approaches a probe • Receives a shock • Now avoids the probe to avoid the shock An example of avoidance
What is punishment
The target response produces an aversive outcome
What is passive avoidance
Safety is achieved by not doing something
Is there a positive or negative contingency between the instrumental response and the aversive stimulus in avoidance?
Negative: If the response occurs, the aversive stimulus is omitted
Is there a positive or negative contingency between the instrumental response and the aversive stimulus in punishment?
Positive: If the response occurs, the aversive stimulus is administered
What is the final result of both avoidance and punishment?
Less contact with the US
What did Vladimir Bechterev do?
He focused on motor responses (called associative responses) - he developed his own procedure on dogs
• Tone was followed by a shock to the forepaw - reflex was to flex the forepaw - the dog avoided getting shock by flexing its paw as soon as he heard the tone (avoidance conditioning)
• Tone = CS (warning stimulus), shock = US, lifting/flexing forepaw = CR (associative response)
What are the main differences between Bechterev and Pavlov’s procedures?
Pavlov: US aversive or appetitive, subjects cannot avoid US, response is to prepare for the US
Bechterev: US always aversive, could learn an avoidance response to avoid the US, response was to avoid the US
What are the 2 types of trials included in the discriminated avoidance procedure?
1-Escape trials - occur early in training
• Participant fails to make the required response during the CS-US interval
• Scheduled shock delivered
2-Avoidance trials - occurs as training progresses
• Participant makes the target response before the shock is delivered
• The CS is turned off and the US is omitted on that trial
What is two-way avoidance?
Animal shuttles back and forth between the 2 sides of the shuttle box
What is one-way avoidance?
Only either side gives a shock; easier to learn avoidance
What is the two-process theory of avoidance?
Basic concept: the absence of something (US) cannot be a reinforcer for a Instrumental response, therefore what reinforces the instrumental avoidance response?
What are the 2 mechanisms involved in avoidance learning?
1-Classical conditioning of fear to the CS
2-Instrumental reinforcement of the avoidance response through fear reduction (reduction of fear induced by the CS, negative reinforcement)
What is the reinforcer for the instrumental response?
The reduction of fear
What are the 3 phases of the Escape from Fear procedure?
- Condition fear to a CS with a pure classical conditioning procedure (association with CS and aversive US)
- Escape from fear training - periodically exposed to the fear eliciting the CS and allowed to perform an instrumental response to turn off the CS
- Escape from fear testing
What is the goal of the Escape from Fear procedure?
demonstrating the contributions of CC and IC when not intermixed
Is fear always present during avoidance behaviour training?
Once individuals learnt that their instrumental response could avoid the US, there was no more fear of the US
There was no more expectation of a shock in the group that learned an instrumental response that allowed to avoid it - however even in the absence of fear the avoidance response was performed
How can we extinguish avoidance behaviour?
- Shuttle box is altered so that the avoidance response is blocked, “flooding” “implosive therapy” with the CS (avoidance behaviour persisted for a long time when subjects could terminate the CS)
- The more time they were blocked from doing the avoidance response to terminate the CS prematurely, the less time they took to reach the extinction criteria (EX: took more than 120sec to reach other side of box = extinction criteria)
- Longer exposures to the CS without the US lead to more successful extinction of avoidance responding
What is nondiscriminated (free-operant) avoidance?
Unsignalled avoidance: no CS announces the US
What is discriminated avoidance
There is a CS before the US, allows for avoidance
What is the SS and RS intervals in free operant avoidance?
S-S interval (shock shock)
Interval between shocks in the absence of a response
R-S interval (response-shock)
Period of safety created by each response
What is the safety signal hypothesis?
Both conditioned inhibitors (spatial cues and interoceptive cues) and positive reinforcement cues work together to reinforce the avoidance response
What is the Reinforcement of Avoidance Through Reduction of Shock Frequency theory?
Avoidance responses prevent the delivery of shock and thereby reduce the frequency of shocks an organism receives - this is what motivates avoidance behaviour (NOT true)
What are Species-specific defense reactions (SSDR)
What animals do in the first trials of learning (instinctive, and mostly dictated by surrounding stimulus (wont run if there is no obvious escape route)
• Freezing, running, burying, etc.
Instrumental response similar to those will be more quickly learned in conditioning (“instinctive”)
What is the predatory imminence continuum?
Different defensive responses occur depending on the level of danger faced by an animal
What is the expectancy theory of avoidance?
Encounters with aversive events trigger a conscious process of threat appraisal that generates expectations of future threat (or lack of threat) based on cues and responses (in humans)
