Incubation and the resolution of tip-of-the-tongue states

Are tip-of-the-tongue (TOT) states better resolved by persistent retrieval efforts, or does an incubation period, i.e., a time away from memory attempts, facilitate resolution? General knowledge questions were given to participants twice, with the retest given either immediately after the participant's first attempt to answer the question, or after a period of incubation during which the participant answered other unrelated questions. When questions were unanswered, they were rated for TOT-strength, ranging from very strong to no TOT. A clear incubation effect was observed; greater resolution of TOTs was found for items retested after a delay than with an immediate retest. The incubation effect and resolution, in general, were greater for stronger TOTs. The results are consistent with a blocking and recovery explanation of TOTs.