Calvin, et al – Experimental Validation of Conditioned Inhibition Flashcards
“Inhibition of Reinforcement”
Occurs only under specific conditions
Since several authors have used the S-R reinforcement theory of extinction as a basis for analyzing spontaneous alternation, the authors set up an experiment to test this
Method
Subjects were albino rats, apparatus was a simple elevated straight alley with a start box and a goal box
Rats were given preliminary training for two weeks prior to be habituated to handling and placed on a 24-hour feeding schedule
They were fed in the goal box
Massed condition = animal then immediately placed in start box for another trial
Spaced conditions = animal was placed on adjacent table for 3 min before being returned to start box
After two weeks, the rats were randomly assigned into one of four groups:
1. Group I, 10-gm, spaced group
- Group II, 10-gm, massed group
- Group III, 12-gm, spaced group
- Group IV, 12-gm, massed group.
Procedures were identical besides variations in drive and massing of trials
Rat placed in start box, door to alleyway opened, time it took to reach goal box recorded
After rat reached goal box, door was closed, and rat allowed to eat from food dish for 10 seconds.
The high drive group were allowed to eat 10 gm. of wet mash, the low drive group were allowed to eat 12 gm. of wet mash
To maximize acquisition of conditioned inhibition, 30 trials a day were implemented, and during 1st and 2nd days, it was occasionally necessary to prod some rats to run, but no rat was prodded after the 3rd day
If rat failed to enter goal box after 5 min, it was placed into goal box
If this occurred on two successive trials, the series was discontinued until next day
Rat was extinguished if rat failed to enter goal box on two successive 5-min trials on two successive days
After a rat extinguished, it was randomly assigned to either a 12- or 24-day post-extinction wait group
At the end of this interval from the extinction day, the rat was rerun for one more series of 30 trials.
Results
All rats extinguished
In addition, when rats were rerun (after 12 or 24 days), all but 3 (2 from the 12-day and 1 from the 24-day group) again extinguished on the post-extinction day
Discussion
All rats ceased to run even though reinforced on every trial confirms the S-R reinforcement theory of extinction.
Other findings include that high drive rats took significantly longer to extinguish then low drive
The failure to find significant differences in running times is not in accord with the theory, though the results were in the expected direction
Faster run times for spaced group rats is expected according to S-R reinforcement theory of extinction, but the difference in days to extinction is not significant, which is not in accord with theoretical expectations.
Summary
Summary
24 naïve albino rats were run down a straight alley 30 trials a day. Half were fed 10 gm. per day, and half 12.
Half were run under spaced conditions and half under massed
All rats stopped running although they were rewarded on every trial
Drive level was significantly related to days to extinction, and massing of trials was significantly related to running time.
