Effects of simultaneous interference upon free recall learning and retention

Learning and retention were examined under varying amounts of intratask interference during learning. All subjects were required to learn the same list of auditorily presented words while concurrently processing a visually presented interfering list. Differential amounts of interference were produced by varying the relatedness of the interfering list to the learning list. The common learning list consisted of four general categories that also contained members of more restricted subcategories. Some subjects were instructed about the existence and names of the subcategories. The results showed that interference lengthened learning but, in some cases, facilitated retention relative to control groups. Restricted category knowledge facilitated learning but had no effect on retention. There were no significant retention differences after I week, but after 5 weeks retention performance was significantly better for groups that learned under related interference conditions. The results were interpreted in terms of more elaborate encoding of the items in the high intratask interference conditions.