Scaling of stimulus duration by pigeons.
Animals time events relative to upcoming reinforcers — schedule changes may shift response patterns at the proportional midpoint.
01Research in Context
What this study did
Four pigeons pecked a key that changed color every few seconds.
Each color stayed on for a short or long time. Food could arrive only at the end of a color.
Birds had to learn when to switch from one color to the next to grab the food.
What they found
The birds switched right at the middle point between two possible food times.
If red lasted 10 s and green 30 s, they swapped around 20 s.
They judged time by how close it felt to the next feeder click, not by counting seconds.
How this fits with other research
HERRNSTEISLOANE (1964) showed pigeons like variable schedules. The 1976 study adds that birds also track the relative distance to those rewards.
Iwata et al. (1990) moved the idea to toddlers. Kids, like pigeons, change how fast they work based on how soon the treat may come.
O'Leary et al. (1979) found people pace their steps under fixed-interval token pay. Together these papers show timing rules work across species and responses.
Why it matters
Your learners also judge when to shift tasks by how "far" the next reinforcer feels, not by clock time. If you stretch the wait for reinforcement, expect earlier off-task behavior. Keep the relative distance short or add cues to reset the "clock" and maintain steady work.
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02At a glance
03Original abstract
Pigeons were presented with a series of key-illumination time periods. During these periods two response keys were lit, one by white light and the other by red or green. White-key responses changed the color on the other key and green- and red-key responses intermittently produced food. Choice responses were reinforced at either of two intervals timed from the onset of the stimulus period. Food was scheduled for green responses during the shorter interval in some stimulus periods and food was scheduled for red-key responses at the longer interval during alternate stimulus periods. The temporal location of food in the stimulus periods was varied across conditions. Across conditions, the pigeons responded on the green key until the time at which green-key responses might be reinforced had passed; then, the probability of red-key responses increased as the time approached at which red-key responses might be reinforced. In all conditions, the pigeons, changed from green-key to red-key responses at the time that was an equal relative temporal distance from the two intervals where these responses were reinforced.
Journal of the experimental analysis of behavior, 1976 · doi:10.1901/jeab.1976.26-15