la Roi, A. 1, 2 , Sprenger, S. 1, 2 & Hendriks, P. 1
1 Center for Language and Cognition Groningen, University of Groningen
2 Neuroimaging Center, University of Groningen
As the population of elderly adults continues to grow worldwide, understanding the cognitive consequences of aging is becoming increasingly important. In younger adults, cognitive functions have been shown to be closely related to successful language processing and comprehension1,2. Yet, how age-related decline in cognitive functions affects language abilities remains largely unknown. Our study examines this question by investigating the processing of idioms, such as the Dutch tegen de lamp lopen ('to walk against the lamp'). To predict an idiom's figurative meaning ('to get caught'), the reader or listener has to inhibit the literal meanings of the idiom constituents ('to walk' and 'lamp'). Since inhibition skills typically decline with age3, increased age is hypothesized to reduce the suppression of literal meanings in idiom processing. As a result, elderly adults may have difficulties predicting an idiom's figurative meaning. To test this hypothesis, we record the event-related potentials of 60 right-handed native speakers of Dutch (aged 18-80) while they read sentences containing an idiom. We measure the amplitude of the N400 evoked by the target word, which is either the idiom's original final noun (lamp 'lamp'), a semantically related word (kaars 'candle'), or a semantically unrelated word (vis 'fish'). The target word is either the final or the penultimate idiom constituent of the sentence. We predict that the degree of activation of an idiom constituent's literal meaning will correlate with age. Literal meaning activation will be reflected by a reduced N400 for semantically related target words compared to semantically unrelated target words and is most likely to be found for sentences in which the target word is the penultimate idiom constituent. By studying idiom processing across the life span we aim to increase our understanding of the relation between cognitive functions and the ability to predict the meaning of ambiguous expressions.