Chaining and secondary reinforcement based on escape from shock.
A stimulus can strengthen the first step in a chain simply because it is part of the path to reinforcement, even if it tells the learner nothing about what to do next.
01Research in Context
What this study did
Researchers built a two-link chain. First, a rat pressed a bar. That turned on white noise. Next, the rat had to poke its nose into a key. The poke turned off both the noise and a mild electric shock.
The white noise never told the rat what to do next. It only came on after the bar press and stayed until the nose poke. The team wanted to know if the noise itself could keep the first response going.
What they found
The bar pressing kept happening even though the noise gave no cue about the next move. The noise worked as a reinforcer all by itself. Its power came from being tied to shock relief, not from guiding behavior.
When the nose-poke link was taken out, bar pressing stopped. The chain needed both steps. The noise alone could not support the first response unless it stayed part of the escape sequence.
How this fits with other research
Neuringer et al. (1968) later showed that tiny one-second timeouts cut errors when teaching new chains. They added instructional lights, but found lights alone produced fake performance without real learning. Both studies warn that cues can look helpful yet hide weak chains.
Wilkins et al. (2009) moved the same logic into an autism classroom. They chained story retelling steps with pictures and text prompts. Their kids learned complex intraverbals, proving that lab chaining rules work in social skills.
Boudreau et al. (2015) later reframed conditioned reinforcement using information theory. They argued a stimulus helps only if it reduces uncertainty about when payoff comes. The 1963 noise fits this view: it did not signal what to do, but it did signal that shock relief was now closer.
Why it matters
You can build early links in a chain even when the middle stimulus gives no cue. Just make that stimulus depend on the first response and reliably lead to reinforcement. Use brief, neutral events—clicks, tones, short lights—as bridges. Check that the later link stays in place; without it, the first response will collapse, just like the bar press did when the nose-poke was removed.
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02At a glance
03Original abstract
Three white rats were trained to press a bar while being shocked. This produced a white noise. After 30 sec they were allowed to terminate both the shock and the noise by nosing a pigeon key. Comparison of the rates of pressing before and after the onset of the noise indicated that the noise itself was the immediate reinforcing agent for pressing. Furthermore, control tests showed that pressing was maintained only if it produced the noise: either omission of the noise or elimination of the dependency of the noise on the occurrence of the response led to a gradual abolition of pressing. When automatic termination of the shock was substituted for the key nosing requirement, however, only the key nosing extinguished. This indicated that the effectiveness of the noise as a reinforcer did not depend on its status as a discriminative stimulus for some other form of operant behavior.
Journal of the experimental analysis of behavior, 1963 · doi:10.1901/jeab.1963.6-75