On the one hand, these retrieval failures can be taken as evidence of weakening connections between the meanings of concepts and the words that denote them in long-term memory. It’s also possible that the increase in word-finding problems with age reflects something very different.
Psychologist Donna Dahlgren has argued that the key issue is not one of age but one of knowledge. If older adults typically have more information in long-term memory, then as a consequence they will experience more TOT states. It’s also possible that TOT states are useful: They can serve as a signal to the older adult that the sought-for word is known, even if not currently accessible.
Research suggests you might have fewer such episodes if you maintain your aerobic fitness. So the next time you have trouble thinking of a word, you can also try looking for it around the block.