Autoshaping, random control, and omission training in the rat.
Past omission training slows later skill acquisition, while random reinforcement history speeds it up.
01Research in Context
What this study did
The team worked with rats in small cages. Each cage had a metal lever and a food cup.
Three groups started different programs. One group got autoshaping: lever light, then food no matter what. Another group got omission training: food only if the rat did NOT touch the lever. The last group got random food with no link to the lever.
What they found
Autoshaping rats touched the lever often and fast. Random-food rats learned slowly. Omission rats almost never touched the lever.
Later, all rats switched to autoshaping. Rats with omission history took longer to start touching again. Rats with random history learned the new task faster.
How this fits with other research
Atnip (1977) ran the same cages the next year. They added operant and classical groups. All lever pressing dropped once omission started, but the lever contacts stayed high. This backs up the 1976 point: topography and contingency can split.
Michael (1974) showed that random food makes rats repeat the last lever for a short time. The 1976 study used that idea as a baseline and proved the random history later speeds up new learning.
Greer (1982) moved the test to pigeons and keys. Key-pecking rose faster when the key looked like the grain hopper. Together the papers say: both stimulus look and past history shape the next response.
Why it matters
Your client’s learning history is in the room with you. If past reinforcement came only for NOT doing the target skill, expect slow startup now. Warm up with low-demand trials or random reinforcement first. Then shift to your main program. Check old data sheets: a past “no touch” rule could explain today’s hesitation.
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02At a glance
03Original abstract
The role of the stimulus-reinforcer contingency in the development and maintenance of lever contact responding was studied in hooded rats. In Experiment I, three groups of experimentally naive rats were trained either on autoshaping, omission training, or a random-control procedure. Subjects trained by the autoshaping procedure responded more consistently than did either random-control or omission-trained subjects. The probability of at least one lever contact per trial was slightly higher in subjects trained by the omission procedure than by the random-control procedure. However, these differences were not maintained during extended training, nor were they evident in total lever-contact frequencies. When omission and random-control subjects were switched to the autoshaping condition, lever contacts increased in all animals, but a pronounced retardation was observed in omission subjects relative to the random-control subjects. In addition, subjects originally exposed to the random-control procedure, and later switched to autoshaping, acquired more rapidly than naive subjects that were exposed only on the autoshaping procedure. In Experiment II, subjects originally trained by an autoshaping procedure were exposed either to an omission, a random-control, or an extinction procedure. No differences were observed among the groups either in the rate at which lever contacts decreased or in the frequency of lever contacts at the end of training. These data implicate prior experience in the interpretation of omission-training effects and suggest limitations in the influence of stimulus-reinforcer relations in autoshaping.
Journal of the experimental analysis of behavior, 1976 · doi:10.1901/jeab.1976.26-451