Stimulus function in simultaneous discrimination.
Extra discrimination trials now can speed up later reversals—use overtraining when you expect rule switches.
01Research in Context
What this study did
Appel (1968) ran pigeons on a simple simultaneous discrimination.
Birds first learned to peck one color and ignore another.
The team then gave some birds extra overtraining before swapping the colors.
What they found
Pigeons that got more early trials reversed faster when the colors switched.
Extra practice built stronger stimulus control that later saved time.
How this fits with other research
Powell et al. (1968) ran the same year with the same birds and task.
They also gave extra discrimination trials and saw tighter inhibitory control.
The two papers are direct replications: more training sharpened later performance.
Snapper et al. (1969) extended the idea.
They showed that discrimination training beats extinction alone for building inhibition.
Together the trio says: drill the S+/S- difference now, and future shifts go quicker.
Why it matters
If you teach a child to sort red vs blue tokens, run extra trials before you later ask for blue vs red.
The early overtraining can cut re-teaching time when contingencies flip.
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02At a glance
03Original abstract
In discrimination learning, the negativity of the stimulus correlated with nonreinforcement (S-) declines after 100 training trials while the stimulus correlated with reinforcement (S+) is paradoxically more positive with lesser amounts of discrimination training. Training subjects on two simultaneous discrimination tasks revealed a within-subjects overlearning reversal effect, where a more-frequently presented discrimination problem was better learned in reversal than was a discrimination problem presented less frequently during training.
Journal of the experimental analysis of behavior, 1968 · doi:10.1901/jeab.1968.11-459