Response rate, reinforcement frequency, and conditioned suppression.
Lean or fast schedules amplify fear responding — schedule parameters are part of emotional intervention plans.
01Research in Context
What this study did
Zeiler (1968) ran two experiments with rats. The rats pressed a lever for food. A tone came on before mild shock. The team varied how fast the rats had to press and how often food followed each press.
They wanted to know if these schedule details change how much the tone alone slows responding.
What they found
Higher lever-press rates made the tone more scary. Fewer food pellets per minute did the same. Both factors increased conditioned suppression — the pause in pressing when the tone sounded.
In plain words, busy schedules and lean payoffs each magnify fear control.
How this fits with other research
Lyon et al. (1966) looked at variable-ratio schedules and saw almost no suppression. Zeiler (1968) now shows the opposite: when you force very high rates or thin the payoff, suppression jumps. The gap is about how the schedules are arranged — VR keeps rates high but steady; the new study pushed rates even higher or cut payoffs further.
Bradshaw et al. (1978) and Wilkie et al. (1981) mapped how sweeter or larger rewards raise response rate on VI schedules. Zeiler (1968) flips the coin: after the rate is set, leaner payoffs boost fear, not speed.
Together the papers say reward frequency sets the baseline rate, then that rate feeds back to decide how strongly fear can brake behavior.
Why it matters
When you thin a schedule to build endurance, watch for emotional side-effects. A child working at high rates or on lean reinforcement may show stronger anxiety cues during novel or aversive events. Buffer sessions with richer schedules or brief breaks to keep the suppression low while you shape tough targets.
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02At a glance
03Original abstract
In the first of two experiments, periods of noise were terminated with unavoidable shock to 36 rats. The rats' continuously reinforced responding was later completely suppressed during the noise when it was introduced without shock. The rats were then assigned to nine experimental groups. Each group was exposed to different paced variable-interval schedules of reinforcement, which independently controlled response rate and reinforcement frequency. Periods of the noise were periodically superimposed on these schedules, and loss of response suppression was studied. Differences between the groups were assessed statistically. The second experiment used a steady-state design. Six rats were exposed to paced schedules which generated two alternating response rates but gave constant reinforcement frequencies, and six rats to schedules which maintained the same response rates throughout, but in which the reinforcement frequency was alternately high and low. Response suppression was studied during a pre-shock stimulus superimposed on each rat's two behavioral baselines. Both experiments suggest that (1) conditioned suppression is affected by rate of operant responding, high rates being most suppressed, and (2) the frequency of reinforcements obtained also has an effect, most suppression occurring when frequency is low.
Journal of the experimental analysis of behavior, 1968 · doi:10.1901/jeab.1968.11-503