Earlier studies have shown that extinction of a stimulus component proceeds faster following extinction of another stimulus component than it does immediately following acquisition. This phenomenon could be attributed either to secondary extinction or some delay of extinction effect. The present study used conditions [immediate extinction, two timed intervals (10 and 20 min.) between acquisition and extinction, and two filled intervals (20 and 40 trials of extinction to another stimulus component) between acquisition and extinction] to distingiush between these two alternatives. The results clearly demonstrate that the rapid extinction noted above reflects something other than secondary extinction.
ThompsonC. P.Van HoesenG. W.Compound conditioning: effects of component intensity on acquisition and extinction. J. comp. physiol. Psychol., 1967, 64, 128–132.
