Age-related differences in the semantic N400 effect are unrelated to semantic benefits in episodic memory

Poster Session F - Tuesday, April 16, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Véronique Huffer¹ (veronique.huffer@uni-saarland.de), Regine Bader¹, Axel Mecklinger¹; ¹Experimental Neuropsychology Unit, Saarland University

Older age is characterized by attenuated episodic memory, but intact semantic memory. At the same time, online semantic processing, particularly the prediction of lexical information, is attenuated, as reflected by a smaller event-related potential (ERP) N400 effect for predictable versus unpredictable items. Using pictorial materials, we investigated whether age-related differences in online semantic processing, as manifested in the N400 attenuation effect, are reflected in a behavioral measure of semantic processing (i.e., perceived semantic congruency) and, in addition, transfer to episodic memory for semantically related object pairs. Younger (YA) and older adults (OA) studied sequentially presented object pairs with and without semantic relationships (e.g., a bathtub followed by a rubber duck or a pillow followed by a punch, respectively). Their task was to judge the object pairs' semantic congruency. Thereafter, an associative memory test was conducted, in which participants had to discriminate between intact, recombined and new object pairs with and without semantic relationships. In the study phase, YA showed the expected N400 attenuation effect for semantically related pairs. For OA, this effect was reduced, even though there was no difference between both age groups in the semantic congruency judgements and both age groups showed highly similar benefits for semantically related versus unrelated pairs in the ensuing associative memory test. Thus, the results are in line with the idea that OA’ associative memory benefit by semantic relationships is decoupled from their online semantic processing, as reflected by the N400 attenuation effect during encoding.

Topic Area: LONG-TERM MEMORY: Development & aging