Dinsmoor: Absurdum Revisited Flashcards
A formal deduction from Hull’s theory of extinction could lead us to some strange predictions…
As training is continued, with reinforcement on every trial, habit strength approaches an asymptote but conditioned inhibition continues to accumulate.
Eventually our S should cease to respond.
There were issues with Hull’s theoretical structure, so in a recent article Calvin and his students try to come to Hull’s rescue.
Their proof turns out to be stranger than Hull’s fiction.
White rats were trained to traverse an elevated runway for a food reward, and, after a number of trails, the authors’ “crucial finding was that all of the Ss extinguished!”
There were three main problems with the condition of Calvin and his students experiment
- There is good reason to suspect that the rats were not very hungry.
They were given 30 trials per day, with 10 sec. of eating per train, 5 min. in all; as a result, “The Ss devoured virtually all of their ration while in the goal box.”
The total daily rations were 10 grams of dry food, mixed with water, for the high drive group, and 12 grams for the low drive group.
These are large ratios, more than some rats can be expected to eat promptly, in my experience, and whatever portion was not eaten during the experimental session was left in the cage, to be consumed possibly as late as a few minutes before the next day’s session.
- Wet food mash, apparently in considerable volume, was available in the goal box as the reinforcement.
In other studies using wet mash it has been observed that many animals scoop up large quantities of this mash in their paws before being taken out of the goal box: the massed animals may have eaten their trove in the start box or at any convenient stopping place along the way to the goal
- The runway was unusually long, extending for 10 feet.
Other Critical Points
Several of the rats among the 24 that started the experiment were discarded for viciousness or illness
If there were some sort of epidemic in the colony, might not other rats become ill, less obviously, and therefore stop running?
Temperature is mentioned as a possible influence in the early extinction of one rat
The rats were trained not to run
Most Es, when they found that reinforced animals were no longer running would look for weaknesses in their procedure–Not so for Calvin, et al.
Their procedure scarcely seems to be such as was envisioned by Hull as an appropriate test for his predictions
