Effects of chlorpromazine in the pigeon under a second-order schedule of food presentation.
Chlorpromazine flips response rates under second-order schedules, proving brief tokens can drive behavior more than food itself.
01Research in Context
What this study did
Scientists gave pigeons a second-order schedule. Birds pecked for brief flashes of light. Food came only after many flashes.
Then they injected chlorpromazine, a calming drug. They watched if peck rates rose or fell. They tracked how flashes versus food steered each bird’s pace.
What they found
The drug acted like a mirror. Slow pigeons pecked faster. Fast pigeons pecked slower.
Brief flashes ruled the moment. Food mattered less. The flash acted like a tiny reward on its own.
How this fits with other research
Macht (1971) removed the drug the next year. When flashes stayed paired with food, birds sped up. When pairings flipped, birds slowed. This proves flashes became conditioned reinforcers.
Craig et al. (2017) moved the idea to rats. They used the same kind of flash clicks to cut resurgence after extinction. The old pigeon hint now helps tame relapse.
Sailor (1971) tested pigeons again. Skipping food sped birds up, extra food slowed them down. Drug or no drug, rate changes follow the same see-saw rule.
Why it matters
You now know brief tokens can outweigh big reinforcers. When you add a click, light, or emoji, treat it like money, not noise. If a client’s response rate is too low, pair that token tighter with the main reward. If rate is too high, thin the token schedule first before you blame the learner.
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02At a glance
03Original abstract
Chlorpromazine was studied for its effects on responding under a second-order schedule in which food was presented following a sequence of 20 one-minute fixed-interval components. A brief visual stimulus occurred at the completion of each fixed interval including the one that terminated with food presentation. Chlorpromazine showed rate-dependent effects in that it increased low rates in the early components of the second-order schedule and, to a lesser extent, decreased high rates in the later components. Chlorpromazine also increased rates in the early quarters within the 1-min fixed-internal components and to a smaller extent decreased rates in the final quarter. The alteration in the patterns of responding within 1-min fixed-interval components terminating in a brief stimulus presentation was substantially less than that which occurred throughout the succession of 1-min fixed-interval components terminating in food presentation, thus suggesting that the presentation of the brief stimulus exerted more control over responding within components than did food presentation over the sequence of components. This result and others suggest that studies using drugs may be useful in elucidating the factors controlling patterns of responding in second-order schedules.
Journal of the experimental analysis of behavior, 1970 · doi:10.1901/jeab.1970.13-291