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Abstract:
It has been proposed that older adults are impaired in the
suppression/ inhibition of irrelevant information. In language
processing this impairment might delay contextual selection i.e.,
the suppression of contextually irrelevant readings of ambiguous
words (e.g., "bark"). To test this, 24 young and 20 older adults
participated in an ERP experiment in which they listened to
naturally produced sentences in four context conditions, followed
by the same target word. Sentence contexts were semantically
neutral but syntactically constraining. (Note: Target words are in
capitals: Concordant/Concordant Control: The blind man ran his
hands across the bark/silk TREE; Discordant/Discordant Control:
Without apparent reason they started to bark/shiver TREE.) The
selectional status of the ambiguous words was inferred from the
ERPs to sentence final and target words. Target words were
presented at ISIs of 100 or 1200 ms in two versions of the
experiment. The results showed multiple activation for the young
adults. The ERPs to the sentence final ambiguous words were more
negative than to their unambiguous controls. Additionally, in the
short ISI a reduced N400 amplitude was found for targets in both
concordant and discordant conditions relative to their controls. In
contrast, evidence for immediate selection was found for the older
adults. These results provide no support for a delay in
suppression/inhibition of irrelevant readings of ambiguous words in
older adults.
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