Looking for immediate and downstream evidence of lexical prediction in eye movements during reading.

Previous investigations of whether readers make predictions about the full identity of upcoming words have focused on the extent to which there are processing consequences when readers encounter linguistic input that is incompatible with their expectations. To date, eye-movement studies have revealed inconsistent evidence of the processing costs that would be expected to accompany lexical prediction. This study investigated whether readers' lexical predictions were observable during or downstream from their initial point of activation. Three experiments assessed readers' eye movements to predictable and unpredictable words, and then to subsequent downstream words, which probed the lingering activation of previously expected words. The results showed novel evidence of processing costs for unexpected input but only when supported by a plausible linguistic environment, suggesting that readers could strategically modulate their predictive processing. However, there was limited evidence that their lexical predictions affected downstream processing. The implications of these findings for understanding the role of prediction in language processing are discussed.