Choice, time allocation, and response rate during stimulus generalization.
Reinforcement density can flip choice in a heartbeat, but response rate takes its time to catch up.
01Research in Context
What this study did
Pigeons pecked two keys under a concurrent VI-VI schedule.
The researchers changed which key paid off more often.
They tracked three things: which key the bird chose, how long it stayed there, and how fast it pecked.
What they found
Choice flipped fast when the richer side switched.
Time on each key followed the same quick jump.
Pecking rate, however, drifted up or down more slowly, forming a smooth curve.
How this fits with other research
Solnick et al. (1977) ran a near-copy of this setup the same year and saw the same split: matching of time but fragile rate control.
Nevin et al. (2005) later showed the rule holds even for conditioned reinforcement: rate can rise without making the response tougher to disrupt.
Kohlenberg (1973) extended the idea to observing responses, proving that keeping the stimulus on for the whole component is what lets density changes steer behavior.
Why it matters
If you want a client to switch tasks quickly, tweak the payoff ratio; choice will follow. Do not assume the old response rate will vanish at the same speed. Plan extra practice or differential reinforcement to bring rate in line after the child has already "chosen" the new activity.
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Join Free →After you change the token rate for two tasks, watch which one the learner picks first, then give extra prompts or denser praise to speed up the actual response rate on that task.
02At a glance
03Original abstract
Six pigeons were trained to discriminate between two noise intensities using a procedure that assessed choice, time allocation, and response rate simultaneously and independently. Responses on the left or right key (R1 or R2) were respectively correct in the presence of two different intensities, S1 and S2. After a correct response, reinforcement became available for pecks on the center key. Reinforcement density for R1|S1 relative to R2|S2 was varied across experimental conditions. Generalization tests followed extensive training at each condition. As a function of stimulus intensity, proportions of initial choices of R2, of time spent in R2-initiated components, and of center-key responses emitted in R2-initiated components all yielded sigmoidal gradients of similar slope, which shifted slightly in location when relative reinforcement density changed. Changeovers were maximal where initial choice proportions approximated 0.5. Gradients relating the absolute number of center-key responses to stimulus intensity were also roughly sigmoidal, but were more sensitive to changes in reinforcement density. Gradients of momentary response rate also depended on reinforcement density. During training, large but transitory shifts in choice responding occurred when reinforcement density changed, while differences in momentary response rate developed slowly, suggesting separate control of choice and response rate by the contingencies of reinforcement.
Journal of the experimental analysis of behavior, 1977 · doi:10.1901/jeab.1977.28-47