The effect of cognitive load on different stages of language prediction: A visual world eye-tracking study

There is evidence that language prediction involves (at least) two stages. The so-called ‘associative’ stage reflects rapid, automatic prediction based on semantic associations (e.g., the verb activating plausible referents), whereas the ‘strategic’ stage reflects slower prediction that integrates contextual information (e.g., the agent’s gender). While cognitive load has been observed to delay prediction, it is currently unknown how it affects these different stages. To address this issue, we conducted two visual world eye-tracking experiments in which participants listened to sentences and viewed arrays of objects. In both experiments, half of the trials involved load, with participants being asked to memorize and subsequently recall five unrelated words. In both the interleaved (Experiment 1) and blocked (Experiment 2) designs, we observed associative effects (more fixations to verb-related targets than distractors) and strategic effects (more fixations to agent-compatible than to incompatible targets). In Experiment 1, both no-load and load trials showed no clear temporal separation between stages, and load delayed associative and strategic effects until after target onset, indicating a possible loss of predictive processing. In Experiment 2, there was evidence for two temporally distinct stages in no-load trials, but under load, the associative effect was delayed, while the strategic effect was unaffected. These results suggest that when cognitive resources are limited, the prediction process is disrupted and no longer shows evidence of separable stages, and prediction is delayed.