[page 9 of handout]
Solomon, R.L., Kamin, L.J. and Wynne, L.C. (1953) Traumatic avoidance learning: the outcomes of several extinction procedures with dogs. Journal of Abnormal and Social Psychology, 48, 291-302.
Ordinary extinction of shuttle-box avoidance responses
Signal was light out in current compartment plus raising of a gate above the hurdle, 10 sec before shock. 10 trials per day, 3 min apart. Training was until 10 consecutive avoidance responses, then 20 days with no shock given.
Results: i. 0/13 dogs stopped responding; ii. dogs developed ritualized behaviour; iii. speed of jumping increased; iv. signs of emotionality decreased. (Excretion, vocalization, resistance to being put in the box)
Extinction with a glass barrier to prevent jumping
The barrier was present only during the middle 4 trials each day, to enforce "reality testing". Normal extinction was given before the glass barrier was introduced
Results: i. 7/9 dogs did not extinguish in 10 days with the barrier; ii. dogs showed emotionality when the barrier was introduced.
Extinction with shock given for jumping
13 dogs received shock for 3 sec after jumping (the gate was lowered to stop retracing).
Results: 10/13 dogs did not extinguish in 10 days (100 trials); ii. the 3 dogs that extinguished showed no spontaneous recovered i.e. did not start again after stopping jumping.
Extinction with the glass barrier and shock for jumping
16 dogs tested which had failed to extinguish in the previous procedures. The barrier was present only during the middle 4 trials each day. 3 sec of shock was given if the dogs jumped on the first 3 or the last 3 of the 10 trials given each day.
Results: i. 14/16 dogs extinguished (10 consecutive trials without jumping) within 7 days; ii. incl. all 6 which had had just the glass barrier before iii. 2 did not extinguish in 10 days.