Performance of rats under concurrent variable-interval schedules of negative reinforcement.
Choice follows the same matching law whether the reinforcer is food or a break from something bad.
01Research in Context
What this study did
Six rats lived in a two-lever box. Each lever turned off mild shock for 30 seconds.
The shocks came at random times. Pressing the left or right lever gave a 30-s break.
The two levers offered different average break chances. The rat chose where to spend time.
What they found
Rats divided their time almost exactly like the breaks were offered. 70 % of breaks on the left lever? 70 % of time stayed there.
The same "matching" pattern seen with food also showed with shock relief.
How this fits with other research
Alba et al. (1972) saw matching with food years earlier. The new study proves the rule still holds when the reinforcer is escape, not food.
Green et al. (1999) later mixed VI and VR schedules. They still saw rough matching, but added that short visits to the lean side can look like optimizing, not pure matching.
Davison et al. (1984) warn matching on VI-VR might be a math artifact. The 1978 paper used only VI, so its clean matching gives stronger evidence for the process itself.
Why it matters
If you run concurrent schedules with escape or break tokens, expect clients to allocate time like the relief available. Keep changeover delays short, track time, not just responses, and you will see the same lawful pattern found with food.
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02At a glance
03Original abstract
The behavior of rats under concurrent variable-interval schedules of negative reinforcement was examined. A single one-minute variable-interval programmer determined the availability of 30-second timeouts from electric shock. These were assigned to one or the other of the two component schedules with a probability of 0 to 1.0. The response requirement for the component schedules was standing to the right or left of the center of the experimental chamber. With a six-second changeover delay, the relative time spent under one component schedule varied directly and linearly with the relative number of timeouts earned under that component schedule. The absolute number of changeovers was highest when a similar number of timeouts was earned under each component schedule, and lowest when all or nearly all timeouts were earned under one component schedule. In general, these relations are similar to those reported with concurrent variable-interval schedules of positive reinforcement.
Journal of the experimental analysis of behavior, 1978 · doi:10.1901/jeab.1978.30-31