Autoshaping in the rat: Effects of omission on the form of the response.
Omission contingencies don’t delete behavior; they sculpt it into a new shape.
01Research in Context
What this study did
Scientists placed a lever inside a rat cage. A light came on, then food dropped into a cup. Soon the rat touched the lever whenever the light appeared.
Next the rule changed. If the rat touched the lever, no food arrived that trial. The team watched how the rat’s movements changed under this “omission” rule.
What they found
Lever touches dropped but did not stop. The rats simply switched body parts. They quit pawing the lever and began nosing it instead.
The form of the response changed while the lever stayed the target. The animals adapted rather than giving up.
How this fits with other research
Lydersen et al. (1974) showed pigeons still pecked a key even when pecking canceled food. Kirby et al. (1981) now finds rats also keep contacting the lever, but they swap paw for nose. Same contingency, different species, different detail.
Jenkins et al. (1973) proved that food type shapes the first form of an autoshaped response. The new study adds a second step: later contingencies can reshape that form again.
Wilkie et al. (1981) debeaked pigeons and saw the birds invent new ways to hit the key. The rat study mirrors this flexibility, showing topography is fluid even after autoshaping ends.
Why it matters
For BCBAs this means extinction or omission does not erase behavior—it remodels it. Watch for new topographies when reinforcement stops. A child may quit hand-flapping but start finger-wiggling for the same sensory payoff. Update your data sheets to catch these subtle shifts and plan intervention accordingly.
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02At a glance
03Original abstract
Two experiments were conducted to investigate the effect of an omission contingency on behavior related to and characterizing autoshaped lever contacts in the rat. In Experiment I an omission contingency imposed on autoshaped lever contacts forceful enough to produce a press (.078N) resulted in a significant decrease in lever presses, but had no effect on frequency of lever touches (contacts of insufficient force to produce a press) or rate of food tray entry during lever presentation. In contrast, rats which received a similar number of lever-food pairings, but whose behavior had no programmed consequences (yoked control subjects), showed an increase in lever press rate, a significant decrease in rate of food tray entry, and no change in rate of lever-touches. In Experiment II, the effect of a similar omission contingency on the topography of lever contact responses was investigated. Prior to omission training subjects contacted the lever primarily by pawing it. Following omission training this behavior was suppressed, with a subsequent increase in lever contacts characterized as nosing. Yoked control subjects showed no significant changes in lever contact topography. The results indicate that (1) an omission contingency does not simply eliminate wholesale those topographies which incur the contingency but produces subtle adaptive changes in lever contact topography; and (2) the nature of the autoshaped response in the rat does not appear to be rigid enough to depend solely upon the nature of the unconditioned stimulus or the conditioned stimulus, but can also be determined by the relationships existing between the animal's behavior and these stimuli.
Journal of the experimental analysis of behavior, 1981 · doi:10.1901/jeab.1981.36-75