Observing responses maintained by conditional discriminative stimuli.
Stimuli that reliably signal upcoming rewards become conditioned reinforcers that keep learners looking.
01Research in Context
What this study did
Pigeons pecked two keys in a conditional-discrimination task.
One key showed a color cue. The cue either predicted food or predicted no food.
The birds could peck a separate ‘observing’ key to see the color cue early.
Researchers counted how often the birds peeked at the cue.
What they found
Pigeons peeked more when the color told them food was coming.
The color itself became a tiny reward — a conditioned reinforcer.
Even though the color gave no extra food, it kept the observing response alive.
How this fits with other research
Hamilton et al. (1978) first showed brief food-paired lights can reinforce key pecks. The 1987 study moves that idea to observing responses.
Meltzer (1983) found pigeons learned best when the unclear cue sat on the non-food key. Together the papers show cue location and cue meaning both guide learning.
Nevin et al. (2005) later built a math model saying reinforcement rate sets ‘attention’ strength. Their model explains why information-bearing cues keep birds looking — the same mechanism Ohta (1987) caught in action.
Why it matters
You can turn neutral stimuli into reinforcers just by letting them signal good news.
In therapy, let a picture, word, or sound announce ‘points coming’ and clients may work to see that cue.
Track how often clients look at or point to the cue — that observing response is your measure of conditioned reinforcement strength.
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02At a glance
03Original abstract
In a conditional discrimination procedure, pigeons' observing responses were analyzed to examine whether two color stimuli (blue or red), conditionally related to whether each of two line stimuli (vertical or horizontal) accompanied reinforcement or nonreinforcement, functioned as conditioned reinforcers. If a variable-interval (VI) 10-s requirement was fulfilled, an observing response produced onset of a color stimulus. A little later, a line stimulus was presented independently of responding, added to the color stimulus to form a compound stimulus. If 55 s elapsed with a response not having occurred either through 55 s or after the variable-interval 10-s had timed out, one of the color-line compound stimuli was presented independently of responding. To control for sensory reinforcement effects and for earlier entrance to the later link, a simple discrimination procedure also was conducted in which reinforcement was not correlated with the color stimuli but with the line stimuli only. As in the conditional discrimination, the observing response also could produce earlier presentation of blue or red. The observing response occurred more frequently during the conditional discrimination than during the simple discrimination. The results were related to different theoretical accounts of conditioned reinforcement, particularly the information hypothesis.
Journal of the experimental analysis of behavior, 1987 · doi:10.1901/jeab.1987.48-355