Chapter 10- Avoidance

Question 1

Avoidance:

Answer 1

• Responding removes aversive outcome
  
  • i.e. open umbrella so you don’t get wet
  • Negative contingency between instrumental response and aversive stimulus

Question 2

Active Avoidance:

Answer 2

• Avoidance conditioning

* Safety is achieved by responding

Question 3

Discriminated Avoidance Procedure:

Answer 3

• Signaled avoidance
  
  • Involves discrete trails, each trial initiated by warning stimulus or CS
  • If participant makes target response before shock is delivered, CS is turned off and US is omitted on that trial (successful avoidance trial)
  • If participant fails to response during CS-US interval, shock delivered and remains on until the response occurs, and both CS and US are terminated (escape trial)
  • At beginning of training, most trials are escape trials, avoidance trials become more prominent as training progresses

Question 4

Shuttle Avoidance:

Answer 4

• Animal placed in shuttle box (box with 2 compartments with an opening seperating them)
  
  • Start on left side of box, CS presented, if animal crosses over to right side, no shock delivered (1 way shuttle avoidance)
  • Procedure repeats with animal starting on right side (2 way shuttle avoidance)
  • 2 way harder to learn because it involves animal returning to side that was dangerous on previous trial

Question 5

Two Process Theory of Avoidance:

Answer 5

• Classical conditioning of fear to CS- Classical conditioning pairs warning stimulus (CS) with aversive event (US) on trials where animal fails to make avoidance response
  
  • CS comes to elicit fear
  • Instrumental reinforcement of avoidance response through fear reduction- avoidance response is learned because response terminates CS, reduces conditioned fear elicited by CS
  • 2 processes depend on each other

Question 6

Escape From Fear Experiments (EFF):

Answer 6

• First condition fear to CS regardless of response
  
  • Animal periodically exposed to fear eliciting CS and allowed to respond to turn off CS (no shocks scheduled in this phase)

Question 7

Independent Measurement of Fear During Acquisition of Avoidance Behaviour:

Answer 7

• If fear motivates avoidance response, and if fear reduction is reinforcing, then conditioning of fear and conditioning of instrumental avoidance behaviour should be correlated
  
  • Wrong- correlated only in early training. After that, responding may persist without fear when CS or warning signal occurs

Question 8

Response Blocking:

Answer 8

• Participants can’t terminate CS (need extensive CS exposure without US)
  
  • In shuttle box, barrier inserted to prevent participant from going to safe side when CS comes on

Question 9

Flooding:

Answer 9

Blocking avoidance response results in participants being exposed to CS for a long time

Question 10

Nondiscriminated (Free-Operant) Avoidance:

Answer 10

• Avoidance conditioning procedure without a warning stimulus
  
  • Aversive stimulus (i.e. shock) occurs periodically without warning (i.e. every 10 seconds)
  • Each time participant makes avoidance response, it obtains a period of safety (i.e 20 seconds) during which no shock is delivered
  • Repetition of avoidance response before end of shock free period restarts safe period

Question 11

S-S Interval:

Answer 11

• Shock- shock interval

* Interval between shocks in absence of a response

Question 12

R-S Interval:

Answer 12

• Response- shock interval
  
  • Period of safety created by each response
  • Avoidance response always sets R-S interval

Question 13

Safety Signals:

Answer 13

• Stimulus that signals absence of an aversive event

* i.e. tactile feedback, light produced after each avoidance response

Question 14

Safety-Signal Hypothesis:

Answer 14

• Safety signals that accompany avoidance responses may provide positive reinforcement for avoidance behaviour
  
  • Introducing feedback stimuli will facilitate learning of avoidance response by becoming a conditioned inhibitor of fear

Question 15

Shock-Frequency Reduction:

Answer 15

• Alternative to 2 process theory
  
  • Reduction of shocks critical to reinforcement of avoidance behaviour
  • Not necessary for avoidance theory (animals can still learn to make an avoidance response even if response does not reduce frequency of shocks delivered)

Question 16

Avoidance and Species-Specific Defense Reactions (SSDRs):

Answer 16

• Aversive stimuli elicit strong unconditioned, innate responses
  
  • i.e. in rats, SSDRs include flight and freezing
  • Environmental context dictates which SSDR predominates (if escape if possible, then flight SSDR kicks in)
  • Instrumental responses similar to SSDRs more easily learned in avoidance experiments

Question 17

Predatory Imminence Continuum:

Answer 17

• Different defensive responses occur depending on the level of danger faced by an animal
  
  • i.e. freezing if rat is close, jumping if snake attacks
  • Response can be conditioned to be elicited by a CS if CS becomes associated with an aversive event
  • If CS presented before US, then response will be one level lower
  • i.e. US-> jumping, CS-> freezing
  • If CS and US presented at same time, response will be more similar to response to US

Question 18

Expectancy Theory:

Answer 18

• Encounters with aversive events trigger a conscious process of threat appraisal that generates expectations of future threat based on cues and responses
  
  • Cue paired with shock elicit expectations of shock, responses that turn off cues and prevent shock elicit expectations of no shock

Question 19

Time Out:

Answer 19

Removal of opportunity to obtain positive reinforcement