Hedging Bets in Linguistic Prediction: Younger and Older Adults Vary in the Breadth of Predictive Processing

Abstract

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.