Response rate under varying frequency of non-contingent reinforcement.
Dense free reinforcers can first spark, then sink, response rates within the same session.
01Research in Context
What this study did
The team watched how often rats pressed a lever when free food dropped at different speeds.
No press was needed to get the food. The food just arrived on its own clock.
They tracked the lever presses minute-by-minute inside each session.
What they found
At first, more free food made the rats press faster.
After a while, the same free food made them press slower.
The curve looked like an upside-down U: up, then down.
How this fits with other research
Cameron et al. (1996) later saw the same minute-by-minute swings when free food topped 120 pieces an hour.
Storch et al. (2012) moved the idea to kids with autism. They showed that mixing two so-so snacks mid-session can pep up responding again, just like the brief rise D et al. saw.
WEINELong (1963) had already shown that richer schedules can lift rates, but D et al. proved the lift can flip to a drop inside one sitting.
Why it matters
When you use non-contingent reinforcement, expect a short burst of work, then a slump.
Watch the clock. If responding fades after ten minutes, add a brief change of item or task to reset the curve.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Graph responses minute-by-minute; if you see a dip after the first third, swap in a fresh toy or snack for two minutes.
02At a glance
03Original abstract
Two White Carneaux hen pigeons were exposed to a 60-sec random-interval baseline procedure. Six different exteroceptive stimuli were successively correlated, within a single session, with blocks of 10 reinforcement presentations. Following this training, a non-contingent reinforcement procedure was instated with inter-reinforcement intervals of 5, 15, 30, 60, 120, and 240 sec. Within a single session, each non-contingent frequency was correlated with one of the previously presented discriminative stimuli. After an initial increase in the rate of responding as the result of a high density of non-contingent reinforcements, the rate declined as exposure to each non-contingent frequency was prolonged.
Journal of the experimental analysis of behavior, 1971 · doi:10.1901/jeab.1971.15-233