Preference and resistance to change with constant- and variable-duration terminal links: independence of reinforcement rate and magnitude.
Reinforcer rate and size add together to guide choice and staying power, so you can trade one for the other while thinning.
01Research in Context
What this study did
The team used pigeons in a lab. Birds pecked two keys.
Each key led to grain for a set time. The grain amount and how often it came varied.
They watched which key the bird chose first and how long it kept pecking when food stopped.
What they found
Faster grain delivery plus bigger grain piles added together. The mix pushed choice and staying power higher.
Rate mattered more than size, yet both helped.
How this fits with other research
Landon et al. (2003) saw the same: bigger rewards make bigger choice spikes. Oliver et al. (2002) just added that rate and size stack.
Levin et al. (2014) later showed large rewards shield both pecking and memory from later tricks like pre-feeding. The 2002 data planted that seed.
Harzem et al. (1978) looks opposite: big grain lengthened the pause right after it. No true clash. They timed the quiet beat; C et al. timed the whole dance.
Why it matters
When you thin a rich schedule, keep both speed and size in mind. Shrink one, keep the other strong, and the client may not notice the leaner patch.
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02At a glance
03Original abstract
Pigeons responded in a three-component multiple concurrent-chains procedure in which the variable-interval reinforcement schedules were the same across components but magnitudes differed across components. The terminal links were arranged either as a variable delay followed by presentation of a reinforcer ("variable duration") or as a fixed period of access to the schedule during which a variable number of reinforcers could be earned ("constant duration"). Relative reinforcement rate was varied parametrically across both types of conditions. After baseline training in each condition, resistance to change of terminal-link responding was assessed by delivering food during the initial links according to a variable-time schedule. Both preference and resistance to change were more sensitive to reinforcement-rate differences in the constant-duration conditions. Sensitivities of preference and resistance to change to relative reinforcement rate did not change depending on relative reinforcement magnitude. Taken together, these results confirm and extend those of prior studies, and suggest that reinforcement rate and magnitude combine additively to determine preference and resistance to change. A single structural relation linking preference and resistance to change describes all the data from this and several related studies.
Journal of the experimental analysis of behavior, 2002 · doi:10.1901/jeab.2002.77-233