Imagine that a stopwatch and a simple category of words are enough to provide a snapshot of your brain health. This is the somewhat disconcerting idea that emerges from recent work on a
15-second verbal fluency test : counting how many words you manage to list very quickly could say a lot about the state of your memory and your executive functions.
This research is part of a worrying context: around 50 million people live with dementia worldwide, with more than 152 million cases expected in 2050. Brain alterations begin more than twenty years before symptoms, and the first signs of decline in semantic memory have been observed up to twelve years before a diagnosis of dementia. It remains to be understood what these few seconds really reveal.
Verbal fluency: what this ultra-short test measures
The semantic verbal fluency test consists of naming, in one minute, as many words as possible belonging to a category (animals, fruits, professions, dishes, furniture). We then divide the performance into four 15-second segments. This task mobilizes the brain health global: semantic memory, access to the lexicon, attention, working memory and search strategies, supported by the hippocampus, temporal and prefrontal cortex.
In clinical practice, similar tests already exist: the Mini Mental State Examination (MMSE) tests orientation, immediate memory and attention; the Five Words Test explores encoding and recall; The Rapid Frontal Efficiency Battery includes lexical evocation (words starting with a letter). These tools are part of a broader assessment of deficits (memory disorders, aphasia, apraxia, executive functions) and their impact on daily life.
The first 15 seconds, a privileged window on cognitive decline
The study at the origin of this new interest followed 74 Spanish-speaking adults over the age of 40 (median 56 years), tested online between 2021 and 2022. All took cognitive (MMSE, MoCA) and psychiatric assessments (MINI Plus interview, Beck scales for depression and Hamilton scales for anxiety), as well as semantic verbal fluency on five categories. The authors specify: “A comprehensive understanding of the dynamics and characteristics of cognitive change is essential for accurately identifying markers that indicate the need for intervention to delay or slow the progression of cognitive decline. Our study seeks to examine the associations between cognitive status and neuropsychiatric morbidity, while also exploring how these associations influence performance on a semantic verbal fluency task,” explained the authors of the study, cited by PsyPost.
The statistical analysis shows that the first 15 seconds slice concentrates the richest information: this “P1” alone forms the main component, explaining 22.8% of the variance in scores. When researchers combine age and performance in these first 15 seconds, they obtain the best predictive models for MoCA (R² = 0.392) and MMSE (R² = 0.237) scores. The following periods (30, 45, 60 seconds) add much fewer elements to distinguish normal cognitive functioning from mild impairment.
A promising tool, to be used with caution and in a clinical setting
The authors point out that the “animals” category, already used in the NEUROPSI standards, remains a good proxy for cognitive status: in their sample, 14.9% of subjects have a “high normal” level, 81.1% “normal” and 4% a mild to moderate impairment. The test remains influenced by age, level of study (the median was 18.7 years of schooling) and mood: higher scores for depression or anxiety are often accompanied by poorer results in fluency, even if these disorders are less well predicted than cognition itself.
For practical use, several points are put forward by neurologists and neuropsychologists:
- These 15 seconds are not enough to diagnose Alzheimer’s disease or dementia;
- A memory complaint may also reflect depression or anxiety with normal tests;
- A serious assessment combines questioning of the patient and those close to them, neurological examination, various tests (MMSE, MoCA, episodic memory tests, verbal fluency) and analysis of the impact on daily activities.
Clearly, this 15-second verbal fluency test appears to be a rapid and sensitive marker of cognitive decline beginner, useful for refining screening and monitoring in a professional setting, rather than a self-test to be interpreted alone at home.