Responding under fixed-ratio and multiple fixed-interval fixed-ratio schedules of electric shock presentation.
Basic schedule patterns stay the same even when the consequence is electric shock instead of food.
01Research in Context
What this study did
Rats pressed a lever for electric shocks. The shocks came on fixed-ratio (FR) or fixed-interval (FI) schedules.
A multiple schedule alternated the two components. Red light meant FR; green light meant FI. The team watched if the animals still showed the classic FR burst and FI scallop even though the “reward” was a brief foot shock.
What they found
The animals kept the usual pattern. FR parts showed fast, steady pressing. FI parts showed the slow-start-to-fast-finish scallop.
The rats acted as if food, not shock, was coming. The color cue let them switch patterns quickly when the schedule changed.
How this fits with other research
AZRIN et al. (1963) saw the opposite effect. They used FR shock as punishment, not reinforcement, and the same schedule now cut responding. The difference is simple: in 1963 the rat’s press produced the shock; in McKearney (1970) the shock was simply delivered for pressing, so it worked like food.
Hamilton et al. (1978) later showed one shock can do both jobs at once—reinforce one lever while punishing another. McKearney (1970) set the stage by proving that shock alone can keep behavior alive.
Pierce et al. (1983) broke the FI scallop into pause, interim, and terminal chunks. Because McKearney (1970) kept the full scallop with shock, we know the chunking rule still holds even when the consequence is aversive.
Why it matters
If you ever use mild aversives or sensory feedback in treatment, remember: the schedule, not the “goodness” of the stimulus, drives the response shape. An FR 10 buzzer will create rapid bursts; an FI 2-min vibration will create a scallop. Match the schedule to the shape you want, and watch for these patterns when you review data.
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Join Free →Graph your client’s response rate minute-by-minute; if you see a scallop or burst, check whether the schedule you set is FI or FR and adjust the cue colors to match.
02At a glance
03Original abstract
Squirrel monkeys, initially trained under a schedule of electric shock postponement and then under fixed-interval schedules of electric shock presentation, were studied under multiple fixed-interval fixed-ratio and under fixed-ratio schedules of shock presentation. Under the fixed-interval (10-min) component of the multiple schedule, a pause was followed by a gradual increase in responding to a rate maintained until shock presentation; under the fixed-ratio (3-, 10-, or 30-response) component of the multiple schedule, a brief pause was typically followed by a relatively high and uniform rate of responding until shock was presented. When the 60-sec timeout periods, which usually followed shock presentation, were eliminated from the multiple schedule for one monkey, responding was only transiently affected. In the one monkey studied, responding was maintained under a fixed-ratio schedule alone (with timeout periods), but rates of responding were lower than under the fixed-ratio component of the multiple schedule. Characteristic patterns of responding, similar to those engendered under schedules of food presentation or shock termination, can be maintained under fixed-ratio schedules of shock presentation; further, patterns of responding can be controlled by discriminative stimuli in multiple schedules.
Journal of the experimental analysis of behavior, 1970 · doi:10.1901/jeab.1970.14-1