Executive functions predict time reference processing in French-speaking people with Alzheimer's disease

The ability to express time through language, known as time reference, is impaired in people with Alzheimer's disease. While cognitive impairments have been documented in this population, particularly in executive functions, few studies have examined how these deficits impact time reference abilities, including tense and grammatical aspect. Since producing time reference requires the integration of grammatical, conceptual, and subjective information, potentially demanding in processing resources, the aim of this study was to investigate whether the cognitive profile (i.e., executive function abilities) of French-speaking people with biologically probable Alzheimer's disease determines their ability in time reference. Verb inflection tasks and cognitive tests were administered to 21 people with a diagnosis of Alzheimer's disease confirmed by cerebrospinal fluid or amyloid positron emission tomography (PET) biomarkers and a control group. Results revealed that individuals with Alzheimer's disease have difficulty with tense and aspect marking, with verbal working memory, inhibition, and mental flexibility playing a significant role in time reference processing. These findings suggest that deficits in executive functions impact the ability of French speakers with Alzheimer's disease to mark tense and grammatical aspect, highlighting the cognitive basis of time reference impairments in this population.