The tip-of-the-tongue (TOT) phenomenon refers to knowing the meaning of the desired information but being unable to produce the phonological information. This study induced the TOT phenomenon through a task involving naming famous people, compared and analyzed results by age, and examined the differences with effects from pathological aging [mild cognitive impairment (MCI)].

Young ( n =10), middle-aged ( n =10), older ( n =10), oldest ( n =10), and MCI ( n =10) subjects participated in this study. To examine TOT rate, rate of TOT response, voluntary TOT solution rate, and TOT solution rate after presenting syllabic cue, each group participated in the experiment through a task of naming famous people.

First, as subject age increased, TOT rate (the number of TOTs divided by total trials) increased. There was no significant difference with pathological aging. Second, normal aging and pathological aging had no significant effect on the rate of TOT response (the number of each response type divided by total response types). Third, the voluntary TOT solution rate (the number of voluntary TOT solutions divided by total TOTs) on occurrence of the TOT phenomenon was very low. Fourth, the TOT solution rate (the number of TOT solutions after presenting syllabic cue divided by total TOTs) had a negative correlation to normal aging. In examining pathological aging, the TOT solution rate of the MCI group was significantly lower than normal oldest people.

Normal aging and pathological aging showed differences regarding TOT rate and TOT solution rate when naming famous individuals. The results of this study could be helpful as a differential tool between normal and pathological aging.