Local patterns of responding maintained by concurrent and multiple schedules.
Short components turn multiple schedules into concurrent ones—time allocation wins, response form fades.
01Research in Context
What this study did
Cohen (1975) watched how pigeons pecked when two schedules ran at the same time or one after the other.
The birds worked on concurrent schedules and on multiple schedules with short or long parts.
The goal was to see if the tiny details of pecking were controlled by local reinforcement or by the way time was split between the two sides.
What they found
On concurrent schedules the birds simply spent time where the grain was richer; the exact shape of each peck string did not matter.
On multiple schedules the same thing happened once the parts became very short; local peck style faded out.
Only when multiple-schedule parts stayed long did the birds keep a special response pattern for each part.
How this fits with other research
Fantino (1969) had already shown that choice follows relative time to food; Cohen (1975) adds that this rule also governs the fine grain of each response.
Reed (1991) later found local contrast early inside a part, a detail L did not test, so the picture now includes brief swings before the steady split.
Malone (1999) offered a stay/switch power model as a rival to the matching rule L used; both accounts predict similar time splits but explain the mechanics differently.
Why it matters
If you run two targets in one session, keep each segment long enough if you want separate topographies.
Let the parts shrink and the learner will just shift time, not form.
Check change-over delays too; Taylor et al. (1993) show long delays also flatten matching, so short, clean parts plus quick switches give you the clearest control.
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02At a glance
03Original abstract
Local patterns of responding were studied when pigeons pecked for food in concurrent variable-interval schedules (Experiment I) and in multiple variable-interval schedules (Experiment II). In Experiment I, similarities in the distribution of interresponse times on the two keys provided further evidence that responding on concurrent schedules is determined more by allocation of time than by changes in local pattern of responding. Relative responding in local intervals since a preceding reinforcement showed consistent deviations from matching between relative responding and relative reinforcement in various postreinforcement intervals. Response rates in local intervals since a preceding changeover showed that rate of responding is not the same on both keys in all postchangeover intervals. The relative amount of time consumed by interchangeover times of a given duration approximately matched relative frequency of reinforced interchangeover times of that duration. However, computer simulation showed that this matching was probably a necessary artifact of concurrent schedules. In Experiment II, when component durations were 180 sec, the relationship between distribution of interresponse times and rate of reinforcement in the component showed that responding was determined by local pattern of responding in the components. Since responding on concurrent schedules appears to be determined by time allocation, this result would establish a behavioral difference between multiple and concurrent schedules. However, when component durations were 5 sec, local pattern of responding in a component (defined by interresponse times) was less important in determining responding than was amount of time spent responding in a component (defined by latencies). In fact, with 5-sec component durations, the relative amount of time spent responding in a component approximately matched relative frequency of reinforcement in the component. Thus, as component durations in multiple schedules decrease, multiple schedules become more like concurrent schedules, in the sense that responding is affected by allocation of time rather than by local pattern of responding.
Journal of the experimental analysis of behavior, 1975 · doi:10.1901/jeab.1975.23-309