An adjusting avoidance schedule.
A lever-press schedule that banks five safe seconds per press produces irregular bursts and lets you see how added cues shift response timing.
01Research in Context
What this study did
SIDMAN (1962) built a new lever-press schedule for rats. Each press added five safe seconds. Shock came only when the safe bank hit zero.
The box had no extra lights or tones. The rat could press any time. The schedule itself created the warning: time running out.
What they found
Rats pressed, but not in a steady rhythm. Bursts came when safe time dropped low. Adding a click warning moved the bursts closer to shock time.
The simple rule let scientists see pure timing effects without extra cues.
How this fits with other research
Blough (1971) later added lights and tones. Auditory cues took over the timing job. The 1962 baseline showed the raw effect first.
Davis et al. (1972) stacked a tone plus light. Response rates jumped higher. The 1962 study set the stage by showing single cues already shift timing.
Wright (1972) swapped the rule for random-interval avoidance. Response rates still followed Herrnstein’s equation. The 1962 adjusting rule opened the door for these parametric tests.
Why it matters
You now know that safety accumulation drives timing even without extra signals. When you add or remove cues, expect bursts to slide closer to the aversive event. Use this to build cleaner avoidance shaping or to test whether a new cue really controls behavior.
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Join Free →Track safe-time left in your avoidance task; add a brief auditory cue and note if response bursts move closer to the shock point.
02At a glance
03Original abstract
A shock-avoidance schedule is described in which the animal accumulated 5 sec of safe time whenever it pressed a lever. With this schedule, the animal was not differentially reinforced for long pauses between responses; and, consistent with this property of the schedule, the probability that the animal would press the lever was not related in any regular way to the amount of time that had elapsed since its preceding lever press. Other features of the performance are also described. If the animal was given a warning stimulus whenever it came within 5 sec of a shock, it tended to spend more time in the close temporal vicinity of the shock and less time at the maximum temporal distance from shock.
Journal of the experimental analysis of behavior, 1962 · doi:10.1901/jeab.1962.5-271