Discrimination learning as a function of stimulus location along an auditory intensity continuum.
Start with a loud S+ sound, then fade volume after the discrimination is strong.
01Research in Context
What this study did
The team worked with rats in a small lab cage.
Each rat had two levers.
A tone came on at different volumes.
Pressing the right lever when the tone was loud gave food.
Pressing when it was quiet did not.
The researchers watched how fast each rat learned the rule.
What they found
Rats learned the rule faster when the loud tone meant food.
Quiet tones as the food cue slowed learning.
Volume mattered more than the team first thought.
How this fits with other research
Thompson et al. (1971) also used tones and two levers in rats.
They switched from volume to location.
Rats still learned fastest when the sound and food side matched.
Both studies show contiguity speeds learning.
McMillan et al. (1967) tested low shock as a cue.
Low shock worked, but learning was slow, just like low-volume tones.
Together the papers say weak stimuli can control behavior, yet they take longer to sink in.
Why it matters
When you teach a child to respond to a sound, start loud.
A loud S+ cuts trial time and boosts correct responses.
Fade volume only after the first discrimination is solid.
This small tweak can save sessions and reduce client frustration.
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02At a glance
03Original abstract
Eight groups of rats were trained on an auditory intensity discrimination in which the discriminative stimuli were separated by 10 decibels (db). Four pairs of stimuli were selected from different regions along a 60-100 db (SPL) intensity continuum. Counterpart groups were trained on each stimulus pair, with the relative intensity positions of the reinforced stimulus (S(D)) and the non-reinforced stimulus (S(Delta)) reversed for the two groups. Discrimination acquisition curves were compared to determine whether stimuli separated by equal logarithmic units were of comparable "difficulty", and to determine the relative effectiveness of an S(D) serving as the more versus less intense member of a stimulus pair. It was concluded that: (1) When S(D) is the more intense, auditory intensities of constant logarithmic separation are graded in "difficulty" along the intensity continuum; high intensity discriminative stimuli are most readily discriminated. When S(Delta) is the more intense, this graded effect is not evident. (2) For a given continuum location, discrimination is inferior when S(Delta) is the more intense. This effect is most pronounced at the high intensity end of the continuum and is chiefly attributable to differences in the rate of S(Delta) responding.
Journal of the experimental analysis of behavior, 1966 · doi:10.1901/jeab.1966.9-219