The effects of unavoidable shocks on a multiple schedule having an avoidance component.
Unsignaled unavoidable shocks can raise response rate and keep it high even after the contingency ends.
01Research in Context
What this study did
Two dogs worked on a two-part lever schedule. In one part, a press postponed shocks. In the other part, presses had no effect. After steady responding was seen, brief shocks were added every few minutes in both parts. The shocks could not be avoided. The team watched how the dogs’ rates changed.
What they found
The extra shocks made the dogs press faster in both parts. The rise stayed even when the avoidance part was switched to extinction. The schedule, not the past payoff, now drove the behavior.
How this fits with other research
KELLEHER et al. (1963) ran almost the same setup with monkeys and saw the same jump. This direct match shows the effect is real across species.
Henton (1972) later showed that shock on a different schedule can cut, not lift, response rate. The same event can help or hurt depending on the program, not on the event alone.
Hearst et al. (1970) added a one-minute tone before each shock. The tone cut avoidance presses and gave the animals more shocks. Their result seems opposite, but the key change is the added signal. A cue that says “shock soon” acts like punishment, while steady, unsignaled shock acts like a reinforcer.
Why it matters
Your client’s “problem” behavior might be kept going by mild, steady aversives you do not notice. Check the schedule, not just the payoff history. If the behavior rises even when rewards stop, look for unsignaled aversives that come on fixed time. Remove or signal them to see the rate drop.
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02At a glance
03Original abstract
Two dogs were maintained on a multiple schedule having both a food reinforced and an avoidance component (Mult VI 1' S(Delta) Avoid(SS20 RS20) S(Delta)). The effects of superimposing an Estes-Skinner procedure for delivering unavoidable shocks on all components of the multiple schedule were observed. The buzzer-shock pairing of the Estes-Skinner procedure produced an increased rate of responding on the avoidance component of the schedule and also on the S(Delta) components. No persistent change in rate was observed on the food component during the pre-shock stimulus. Control performances on all components could be regained by either extinguishing or eliminating the buzzer-shock pairing. Extinction of the avoidance responding had little effect on the increased rates of responding produced by the Estes-Skinner procedure on the S(Delta) and avoidance extinction components and did not lead to a conditioned suppression of the food reinforced responding. Rate of responding during the pre-shock stimulus was observed to be relatively independent of changes in the maintaining schedules. Responding during the pre-shock stimulus could be conditioned and maintained after an extensive history of avoidance extinction.
Journal of the experimental analysis of behavior, 1963 · doi:10.1901/jeab.1963.6-29