Comprehending idioms (e.g., bite the bullet) requires that people appreciate their figurative meanings while suppressing literal interpretations of the phrase. While much is known about idioms, an open question is how healthy aging and noncanonical form presentation affect idiom comprehension when the task is to read sentences silently for comprehension. Here, younger and older adults read sentences containing idioms or literal phrases, while we monitored their eye movements. Idioms were presented in a canonical or a noncanonical form (e.g., bite the iron bullet). To assess whether people integrate figurative or literal interpretations of idioms, a disambiguating region that was figuratively or literally biased followed the idiom in each sentence. During early stages of reading, older adults showed facilitation for canonical idioms, suggesting a greater sensitivity to stored idiomatic forms. During later stages of reading, older adults showed slower reading times when canonical idioms were biased toward their literal interpretation, suggesting they were more likely to interpret idioms figuratively on the first pass. In contrast, noncanonical form presentation slowed comprehension of figurative meanings comparably in younger and older participants. We conclude that idioms may be more strongly entrenched in older adults, and that noncanonical form presentation slows comprehension of figurative meanings.

Prediction facilitates word processing in the moment, but the longer-term consequences of prediction remain unclear. We investigated whether prediction error during language encoding enhances memory for words later on. German-speaking participants read sentences in which the gender marking of the pre-nominal article was consistent or inconsistent with the predictable noun. During subsequent word recognition, we probed participants' recognition memory for predictable and unpredictable nouns. Our results indicate that individuals who demonstrated early prediction error during sentence reading, showed enhanced recognition memory for nouns overall. Results from an exploratory step-wise regression showed that prenominal prediction error and general reading speed were the best proxies for recognition memory. Hence, prediction error may facilitate recognition by furnishing memory traces built during initial reading of the sentences. Results are discussed in the light of hypotheses positing that predictable words show a memory disadvantage because they are processed less thoroughly.

How do violations of predictability and plausibility affect online language processing? How does it affect longer-term memory and learning when predictions are disconfirmed by plausible or implausible words? We investigated these questions using a self-paced sentence reading and noun recognition task. Critical sentences violated predictability or plausibility or both, for example, “Since Anne is afraid of spiders, she doesn’t like going down into the … basement (predictable, plausible), garden (unpredictable, somewhat plausible), moon (unpredictable, deeply implausible).” Results from sentence reading showed earlier-emerging effects of predictability violations on the critical noun, but later-emerging effects of plausibility violations after the noun. Recognition memory was exclusively enhanced for deeply implausible nouns. The earlier-emerging predictability effect indicates that having word form predictions disconfirmed is registered very early in the processing stream, irrespective of semantics. The later-emerging plausibility effect supports models that argue for a staged architecture of reading comprehension, where plausibility only affects a post-lexical integration stage. Our memory results suggest that, in order to facilitate memory and learning, a certain magnitude of prediction error is required.

Language processing is predictive in nature, but it is unknown whether language users generate multiple predictions about upcoming content simultaneously or whether spreading activation from one pre-activated word facilitates other words downstream. Simultaneously, developmental accounts of predictive processing simultaneously highlight potential tension among spreading activation vs. multiple activation accounts. We used self-paced reading to investigate if younger and older readers of German generate (multiple) graded predictions about the grammatical gender of nouns. Gradedness in predictions was operationalized as the difference in cloze probability between the most likely and second-most likely continuation that could complete a sentence. Sentences with a greater probabilistic difference were considered as imbalanced and more biased towards one gender. Sentences with lower probabilistic differences were considered to be more balanced towards multiple genders. Both young and older adults engaged in predictive processing. However, only younger adults activated multiple predictions, with slower reading times (RTs) when gender representations were balanced, but facilitation when one gender was more likely than others. In contrast, older adults’ RTs did not pattern with imbalance but merely with predictability, showing that, while able to generate predictions based on context, older adults did not predict multiple gender continuations. Hence, our findings suggest that (younger) language users generate graded predictions about upcoming content, by weighing possible sentence continuations according to their difference in cloze probability. Compared to younger adults, older adults’ predictions are reduced in scope. The results provide novel theoretical insights into the developmental mechanisms involved in predictive processing.