Action at a temporal distance: Component transition as the relational basis for successive discrimination.
Stimulus control fades quickly after a schedule component starts, so place your cues early or add brief signals later.
01Research in Context
What this study did
The team ran five small lab experiments with successive schedules. Each schedule had two parts, or components, that switched back and forth.
They asked a simple question: does the stimulus control the moment a new component starts stay just as strong later in that same part? They used a math tool called a power-function exponent to measure how tight the control was.
What they found
Control dropped the longer the component lasted. The exponent got smaller in a smooth curve as seconds ticked by.
In plain words, the signal that tells the learner "rules just changed" loses power fast. After a short wait, behavior starts to drift.
How this fits with other research
Farmer et al. (1966) first mapped how a 6-second light moved around inside a fixed-interval schedule. White (1995) turns that idea outward, showing control fades even when the signal stays on.
Reed (1991) saw local contrast spike early in a component. White (1995) adds the mirror image: late in the component, stimulus control is weakest.
Sherwell et al. (2014) later showed brief extra cues can sharpen timing. Together the story is clear: place cues close to the transition, or add new ones, to keep control tight.
Why it matters
If you run DRL, multiple schedules, or any session with clear parts, plan your prompts and SDs for the first seconds after the switch. Wait too long and the learner may act under old rules. Quick transition cues, color changes, or a short vocal prompt can rebuild the stimulus control you need.
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02At a glance
03Original abstract
In a successive discrimination, red and green hues signaled component variable-interval schedules. The exponent of the power function relating ratios of responses in the red and green components to ratios of reinforcers provided a reinforcement-free measure of discrimination or stimulus control. Responses were recorded in successive 10-s subintervals of the 50-s components. The power-function exponent decreased systematically with increasing time since component transition in most conditions of five experiments. This reduction was not influenced by the absolute rate of reinforcement, consistent with the interpretation of the exponent as a measure of stimulus control. A reduction in the overall level of stimulus control by increasing the duration of response-produced keylight offset did not influence the decrease in discrimination with increasing time since component transition. The results support the conclusion that discriminative responding in successive discriminations is governed by several sources of stimulus control including delayed control by component transition.
Journal of the experimental analysis of behavior, 1995 · doi:10.1901/jeab.1995.64-185