Time changes in the strengths of A–B, A–C lists; spontaneous recovery?

Summary This study examined the availability (MMFR) of responses from two (A-B, A-C) consecutively-learned lists of paired-associate adjectives, and from an only-learned list, after seven retention intervals varying from 1 min. to one week. As expected, the retention of the first of the two lists was far poorer than the second at short retention intervals, but the two were approximately equal after retention intervals of 24 hours and more. However, contrary to expectation, the first list showed neither absolute recovery, nor even relative recovery when the standard was the only-learned list. Comparison of the retention of the second list and the only list showed that the second list suffered proactive inhibition of response availability at longer retention intervals (24 hours and more). Both of these developments were seen as contrary to existing conceptions in two-factor interference theory, and some revisions were suggested.