Language, memory, and aging: an electrophysiological exploration of the N400 during reading of memory-demanding sentences.
Twenty-four young and 24 middle-aged academics carried out a language recognition task in which sentences were presented that made either a high or a low demand on working memory (WM). The sentences ended either normally (i.e., congruent) or with an incongruous word. Middle-aged subjects had smaller WM scores, a marginally slowed down recognition performance, and a smaller and delayed N400 component. The event-related potential (ERP) difference between congruent and incongruent endings was smaller in the high-load condition for younger subjects and totally disappeared for the middle-aged subjects. ERPs for all subjects showed a WM-related positivity in the middle of the sentence and a WM-related negativity at the sentence ending. These shifts could be associated with either storage and retrieval processes or with clause wrap-up processes. Most ERP-effects were dependent on WM capacity. Age differences in sentence processing are not simply explained by age itself but depend to a large extent on individual memory capacity.
Gunter
T C
TC
Institute for Experimental and Occupational Psychology, University of Groningen, The Netherlands.
Jackson
J L
JL
Mulder
G
G
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D011340:Problem Solving / Q000502:physiology; D011932:Reading; D012660:Semantics; D014706:Verbal Learning / Q000502:physiology*