Titration of schedule parameters by pigeons.
Pigeons can self-adjust reinforcement schedules to match known standards, proving the quantitative law of effect and giving us a tool to let clients choose their own optimal work rate.
01Research in Context
What this study did
Pigeons could peck one key to raise or lower the work requirement on a second key.
The second key paid off on fixed-interval or fixed-ratio schedules.
Birds kept adjusting until the schedule felt like a standard FI or FR value they had experienced before.
What they found
The pigeons landed on the same FI and FR values every time.
Their chosen settings matched the numbers predicted by Herrnstein’s law of effect.
Animals can dial reinforcement schedules to equivalence without any help.
How this fits with other research
HERRNSTEISLOANE (1964) showed pigeons track relative reinforcement rate. Lea (1976) adds that birds can also set the rate themselves.
Davison et al. (1995) later proved you can train pigeons to break the matching rule when a clear stimulus signals the richer option. Together the three papers show: matching is real, but it can be shaped away.
Pliskoff et al. (1972) used similar VI schedules and found that reinforcing high rates in one component sped up responding in another unchanged component. E’s titration method gives a cleaner baseline for spotting these induction effects.
Why it matters
If an animal can self-titrate, so can a person. Let learners adjust task difficulty or break size during discrete-trial or token sessions. Watch where they settle; those settings reveal the true reinforcement value. Use this data to individualize programs without long pilot phases.
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02At a glance
03Original abstract
Pigeons were tested in a computer-controlled two-key chamber. A standard (nonchanging) schedule of reinforcement was in force on one key, and an adjusting schedule on the other. The schedules were available concurrently after each reinforcement, but after the first peck on either key (the choice peck), the schedule on the other key was made inoperative. The parameter of the adjusting schedule was decreased when the standard schedule was chosen and increased when the adjusting schedule was chosen. The standard schedule was changed only between sessions. Fixed intervals and fixed ratios were used as standard schedules, and intervals and ratios were used as adjusting schedules. When standard and adjusting schedules were of the same type, median parameters on the adjusting key equalled those of the standard schedules, at four values of each standard schedule. For four of five birds, and for the group median, similar curves could be plotted through the indifference points obtained from a standard ratio with an adjusting interval, and from a standard interval with an adjusting ratio. These points showed consistent individual differences, but they could be predicted by assuming that the median time from the choice peck to reinforcement should be the same on both keys. This is equivalent to treating the schedule as a concurrent chain and assuming that Herrnstein's quantitative law of effect applies.
Journal of the experimental analysis of behavior, 1976 · doi:10.1901/jeab.1976.25-43