Effects of Semantic Interference and Facilitation on Lexical Retrieval: Evolution in Healthy Aging

Word retrieval difficulties, such as anomia, increase with age. While some language functions, like semantic knowledge, remain stable or improve, lexical retrieval declines, due to reduced processing speed, weaker inhibition, and increased lexical competition. The Picture-Word Interference (PWI) paradigm is commonly used to study these effects. Taxonomic relations (e.g. cow - horse) tend to increase interference, whereas thematic relations (e.g. cow - milk) may facilitate retrieval. This study investigates how semantic links influence lexical retrieval and whether these effects vary with age.

Fifty-five French-speaking adults (30 young, 25 elderly) performed a PWI task (i.e. a picture is shown with a written distractor word) with four conditions: taxonomic, thematic, unrelated, and neutral.

Elderly adults responded more slowly and less accurately overall. However, taxonomic distractors consistently caused the greatest interference eliciting the longest reaction times and lowest accuracy - in both age groups. Thematic and unrelated distractors produced moderate interference compared to the neutral condition.

Semantic relationships distinctly influence lexical retrieval, regardless of age. Age-related differences mainly manifested in speed and accuracy while the structure of semantic interference is overall consistent across ages, underscoring, respectively, cognitive slowing and reduced inhibitory control in aging. Preserved semantic knowledge in elderly adults appears to mitigate some of these difficulties, highlighting its compensatory role in language production. The findings highlight the specific role of semantic relations in lexical access and confirm that aging affects processing speed more than semantic network structure.