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Aging Effects on Associative and Conceptual Semantic Priming: Behavioral and EEG Evidence Across Short and Long SOAs
Poster Session F, Friday, October 2, 2:45 - 4:45 pm, Wangari Maathai
XIBIN WANG1, Fréderic ISEL2, Karin HEIDLMAYR1; 1MoDyCo - UMR7114, 2LPP - UMR7018
Semantic priming may rely on multiple cognitive mechanisms rather than a single semantic system. The present study investigates the temporal dynamics of perceptual (shared sensory or physical features), associative (words that frequently co-occur in the same context), conceptual (abstract categorial relation independent of co-occurrence) and classic semantic (associative plus conceptual relation) relations in lexical processing, and the effects of healthy aging on these processes. This study compared priming effects at 150 ms and 300 ms SOAs. We hypothesized that associative priming effects would be stronger at short SOAs, whereas conceptual priming effects would become more prominent at longer SOAs. Twenty-nine young adults and twenty-six healthy older adults, all native French speakers, were administered a semantic priming paradigm and performed a lexical decision task while EEG was recorded. Stimuli included perceptual color relations (teeth - salt), perceptual action relations (screw - key), associative relations (chicken - sauce), conceptual relations (beer - barley), classical semantic relations (apple - pear). Stimuli were randomly assigned to 150 ms or 300 ms SOA conditions. Behavioral analyses focused on reaction times and accuracy. EEG analyses targeted the N170 and N400 components. Behavioral results revealed no main effect of age on reaction times, suggesting preserved semantic processing speed when semantic knowledge was controlled. However, age interacted with priming effects. At SOA 150 ms, young adults showed semantic priming for classical semantic relations (b = -0,054 ± 0,016, p = 0,003), whereas older adults showed no reliable priming effect. At SOA 300 ms, young adults demonstrated associative priming (b = -0,046 ± 0,016, p = 0,017), while older adults showed only a tendency toward semantic priming. Older adults also showed higher accuracy (χ²(5) = 39,6, p < 0,001). No significant behavioral or ERP priming effects were observed for perceptual relations. EEG analyses revealed a significant age effect on the posterior N170 component (150–250 ms), with young adults showing less negative amplitudes than older adults. Young adults exhibited an N170 facilitation effect for associative relations at SOA 150 ms and N400 facilitation effects for associative, conceptual, and classical semantic relations at SOA 300 ms. Older adults showed N400 facilitation for conceptual relations at both SOAs and for classical semantic relations at SOA 300 ms, as well as an inhibitory N170 effect for classical semantic relations at SOA 300 ms. Whereas behavioral effects only partially supported the predicted temporal dynamics, ERP findings were more consistent with the initial hypotheses. ERP analyses confirmed the hypothesized temporal dissociation between associative and conceptual processing. These findings suggest that semantic priming involves multiple temporally distinct mechanisms. Associative processing appears to be reflected by the N170 component, and is particularly sensitive to aging, whereas conceptual processing indexed by the N400 appears relatively preserved. Young adults relied primarily on associative processing at shorter SOAs and recruited both associative and conceptual processing at longer SOAs. Older adults may rely more heavily on conceptual semantic knowledge with reduced associative processing. Overall, healthy aging appears to alter the dynamics of semantic activation rather than producing a generalized semantic deficit.
Topic Areas: Meaning: Lexical Semantics, Disorders: Acquired