🧠 Losing your words? That's perfectly normal!

By Monica Baciu, Professor of Cognitive Neuroscience, Université Grenoble Alpes (UGA) and Clément Guichet, Postdoctoral Researcher, Université Grenoble Alpes (UGA)

"What's it called again?" The word is right there. You can feel it within reach, almost accessible, "on the tip of your tongue," but you can't say it right away. So you skirt around it, rephrase, wait a few seconds. Then, often, the word comes back. This very common phenomenon, starting in midlife, is often perceived as a worrying sign of aging. However, our research in cognitive neuroscience tells a much more nuanced, and above all much less pessimistic, story.

For several years, our work has been studying how the brain ages and reorganizes its language functions. Results obtained since 2021 show that difficulty finding words does not necessarily indicate an overall decline in memory or intelligence. It mainly reflects a gradual transformation of the strategies the brain uses to access language.


Contrary to popular belief, words do not disappear from our memory with age. Knowledge generally remains very solid, and vocabulary often continues to expand thanks to experience accumulated over the years. What changes more is the speed with which the brain accesses this knowledge.

Speaking is an extremely sophisticated action

To understand this phenomenon, it is important to remember that speaking is an extremely sophisticated operation. When we produce a word, the brain must first activate its meaning, for example the idea of an object, a person, or an action, then retrieve its sound form before preparing its articulation.

In our recent work on language aging, we distinguish two essential dimensions. The first is the semantic dimension, that is, the meaning of words, the knowledge and associations built through experience. The second is the phonological dimension, which corresponds to the sounds that allow words to be pronounced. For example, when you say the word "cat," you first retrieve its mental representation from memory, then you transform that representation into a series of sounds that make its articulation possible.

With age, the systems related to meaning remain particularly robust. However, access to the exact sound form of words sometimes becomes less fluid, as it is more vulnerable to the effects of age. In short, the brain does retrieve the idea of the word, but its phonological retrieval requires increased mobilization of cognitive resources. This is precisely what produces the feeling of the word being "on the tip of the tongue".

New strategies

Our research conducted since 2021 shows, however, that the brain does not passively undergo these changes. On the contrary, it develops new adaptation strategies.

As rapid processing based on the sounds of words becomes less efficient, the brain relies more on semantic knowledge, context, and accumulated experience. Phonological and semantic mechanisms are not mutually exclusive and continue to function in interaction. However, brain changes associated with healthy aging seem to gradually increase the contribution of semantic systems, which then participate in compensating for phonological weaknesses.

In other words, when direct access to a word becomes more difficult, the brain compensates by mobilizing more meaning and associations. This reorganization is also accompanied by greater involvement of systems related to attention and sensory organs that help select relevant information.

Our more recent work shows that these adaptations are not limited to language itself. They reflect a more interactive reorganization of brain function during aging that particularly impacts memory and attention.

From about age 55, we observe progressive changes in brain networks involved in language and communication. This reorganization is also evident at the brain network level. Recent work using magnetoencephalography (MEG) suggests that it tends to group semantic representations into larger, more stable units by associating them with visual or motor representations. To use our example again, the processing of the word "cat," from its retrieval in memory to its articulation, would be increasingly mediated by image, sound, or movement, to facilitate language.

Our research conducted over the past three years also suggests that these changes follow a more general energetic logic of the brain. With aging, certain long and costly brain connections, such as those of the phonological system, become more vulnerable. In response, the brain tends to favor more local, more energy-efficient circuits, criteria that the systems related to meaning and experience seem to meet.

Brain aging thus appears less as a brutal degradation than as a constant search for balance between processing efficiency and energy economy.

Cognitive reserve

It is also important to emphasize that this evolution varies greatly from one individual to another. Some people retain great verbal fluency very late in life, while others experience earlier difficulties. Part of these differences is linked to what neuroscience calls cognitive reserve.

Cognitive reserve corresponds to the brain's ability to adapt to changes and mobilize alternative strategies. It is influenced by many factors such as education level, intellectual activities, social interactions, physical activity, or multilingualism. The greater this reserve, the more the brain seems able to compensate for the effects of aging.

It is precisely this diversity of individual trajectories that we are studying today to better understand why some brains remain particularly adaptable with age and to identify vulnerability trajectories earlier using artificial intelligence and brain network analysis.

This work contributes to a broader transformation in how brain health is approached. Today, research increasingly aims to detect early signs of frailty before the onset of more significant cognitive disorders. For example, the increase in "tip-of-the-tongue" sensations precedes measurable cognitive difficulties in other cognitive domains. It is in this context that brain health centers are emerging, developing prevention approaches based on early identification of individuals who may feel slowdowns in their cognitive skills, but without objective measures showing deficits in these functions.

In conclusion, during healthy cognitive aging, the word almost always comes back. And when it is a little slow, it does not necessarily mean that the brain is losing its abilities. It may simply indicate that it is modifying its strategies to continue functioning differently.