Effects of concurrent schedules on human fixed-interval performance.
Side schedules flip FI responding: DRL keeps humans pressing fast, FR makes them pause.
01Research in Context
What this study did
College students pressed a lever for money on a fixed-interval schedule.
The FI 1-min schedule ran at the same time as a second schedule.
One group also had to wait 20 s between presses to earn extra cash.
The other group had to press 100 times fast to earn extra cash.
What they found
The wait group kept pressing fast and steady on the FI.
They rarely paused after the payoff.
The 100-press group slowed way down on the FI.
They took long breaks after each payoff.
How this fits with other research
Pisacreta (1982) later showed these patterns stick even when you change the rules.
English et al. (1995) tried to copy the fast steady pattern with rats but could not.
The rat study proves the pattern is human-specific, not just about past training.
Wearden et al. (1983) found pauses under FI are weakly linked across intervals.
The current study shows concurrent rules can override that natural pause habit.
Why it matters
If you run a DRL side schedule to cut rate, watch out — it may spike FI rate instead.
If you run a high-ratio side schedule, expect long FI pauses and slower progress.
Test each concurrent combo before you lock it into a treatment plan.
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02At a glance
03Original abstract
Young adults performed a lever-pressing task for money on two schedules of reinforcement: concurrent fixed-interval 1 min-differential-reinforcement-of-low-rate 20-sec, and concurrent fixed-interval 1-min-fixed ratio 100 responses. All subjects were trained on both schedules. Fixed-interval performance concurrent with the differential reinforcement procedure was characterized by high constant rates with no post-reinforcement pauses. Fixed-interval performance concurrent with fixed ratio was characterized by low rates and lengthy post-reinforcement pauses. These results differ from those obtained in prior studies on the effects of conditioning history upon subsequent fixed-interval performance. The prior work, using non-concurrent procedures, had shown that fixed-interval performance following differential reinforcement of low rates was characterized by post-reinforcement pauses and low rates, while fixed-interval performance following fixed ratio exhibited high constant rates and no post-reinforcement pause. The present results suggest that alternative concurrent contingencies are another major determinant of human fixed-interval performance.
Journal of the experimental analysis of behavior, 1972 · doi:10.1901/jeab.1972.18-119