Sequence schedules of reinforcement.
Schedule type within a chain can raise or lower response speed even when overall payoff rate stays put.
01Research in Context
What this study did
Macht (1971) worked with pigeons to test two chain schedules.
Each chain had three links. One chain used fixed-interval (FI) links. The other used fixed-ratio (FR) links.
Food came at the same overall rate in both chains. The only difference was the rule inside each link.
What they found
Birds pecked faster in the FI chain than in the FR chain.
The pattern of pecks also looked different across the two chains.
Even though payoff timing stayed the same, schedule shape changed how the birds responded.
How this fits with other research
Rider (1980) later saw the opposite: bigger FR sizes slowed pigeons down. Together the papers show both chain type and ratio size tune response speed.
Okouchi (2003) found that past FR exposure speeds up later FI responding in humans. J’s birds may have carried similar history effects into the FI chain.
Glynn (1970) and Robertson et al. (2013) both mapped classic FI break-and-run patterns. J’s FI chain matched those patterns, confirming the signature pause-run shape holds inside sequences.
Why it matters
The study warns us that schedule structure alone can push response rates up or down, even when reward timing stays flat. When you build token boards or chain schedules for clients, think about the rule in each link, not just how often the reinforcer lands. Try swapping an FR link for an FI link if you want quicker responding without adding extra reinforcement cost.
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02At a glance
03Original abstract
The performance of pigeons was studied under a second-order schedule composed of fixed-interval components, each of which was associated with a different discriminative stimulus, the stimuli occurring in a fixed order. In one condition, food presentation followed the completion of the fourth component. This was designated a fixed-ratio sequence schedule. In another condition, responses in the first component completed after a fixed time were reinforced. This was designated a fixed-interval sequence schedule. Although the stimulus order and maximum reinforcement frequency were identical under the two schedules, considerably more responding occurred under the fixed-interval sequence schedule in all components. Relatively few food presentations occurred after responding during any but the terminal components of the fixed-interval sequence schedule, a feature independent of the parameter values investigated. In addition, while a pattern of increased responding between food presentations prevailed under both schedules, under the fixed-interval sequence schedule the rate in the terminal component was frequently less than in the penultimate component. The fixed-interval sequence schedule appeared to have several properties of simple fixed-interval schedules.
Journal of the experimental analysis of behavior, 1971 · doi:10.1901/jeab.1971.15-41