Discrimination of a response-independent component in a multiple schedule.
Pigeons can spot when their pecks no longer control food, showing stimulus control over schedule type.
01Research in Context
What this study did
Researchers put pigeons in a two-part schedule. One part gave food no matter what the bird did. The other part gave food only after a peck.
A light or tone told the bird which part was active. The team watched whether the pigeons could learn to tell the two parts apart.
What they found
The birds pecked more during the response-dependent part and less during the free-food part. That shows they noticed when their own pecks mattered.
Earlier training and the exact cue used shaped how fast the discrimination formed.
How this fits with other research
Mandell (1984) repeated the idea with a new twist. Instead of schedule type, birds had to tell how often food arrived. Both studies prove pigeons can track response-independent events, just using different cues.
Poling et al. (1977) took the same baseline and added a conditional rule. Birds still passed the test even when pecking no longer paid off. That extends the 1973 finding to harder, extinction-proof discriminations.
Adams (1980) and Rapport et al. (1982) show pigeons can also use their own recent acts—peck count or pauses—as cues. Together these papers map how schedule, frequency, and response cues all can gain stimulus control.
Why it matters
If a pigeon can tell when its pecks don't matter, so can a child. When you run free-operant teaching, mix in brief periods where responses have no payoff. Use a clear stimulus to mark those periods. The learner will notice the difference and save effort when rewards are response-independent, just like the birds did.
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02At a glance
03Original abstract
Pigeons were trained to respond in non-differential reinforcement pre-discrimination training, with a multiple variable-interval 1-min variable-interval 1-min schedule. Each bird then received discrimination training with a multiple variable-interval 1-min variable-time 1-min schedule. Thus, discrimination training was between response-dependent (variable-interval) and response-independent (variable-time) schedules with the rate of reinforcement equated. In Experiment I, only three sessions of non-differential reinforcement preceded discrimination training and for half the birds, a 0 degrees line was correlated with the response-dependent schedule; for the remaining birds the 0 degrees line was correlated with the response-independent schedule. Post-discrimination gradients of excitatory stimulus control were obtained from the former group, while the latter group showed little evidence of post-discrimination stimulus control by the 0 degrees line. Differential responding to the variable-time schedule was not accompanied by behavioral contrast to the variable-interval schedule. In Experiment II, 20 sessions of non-differential reinforcement preceded discrimination training and the 0 degrees line was correlated with variable-time reinforcement for each bird. Differential responding to the 0 degrees line was accompanied by negative induction to the variable-interval schedule and by inhibitory stimulus control about the 0 degrees line during a post-discrimination generalization test.
Journal of the experimental analysis of behavior, 1973 · doi:10.1901/jeab.1973.19-55