Local word statistics affect reading times independently of surprisal
This challenges the surprisal theory in psycholinguistics by showing that local statistics play a significant role in sentence processing, potentially motivating new theoretical generalizations.
The study investigated whether local word statistics, beyond just word frequency, affect reading times independently of surprisal, and found that word bigram and trigram probabilities also influence processing independently of surprisal.
Surprisal theory has provided a unifying framework for understanding many phenomena in sentence processing (Hale, 2001; Levy, 2008a), positing that a word's conditional probability given all prior context fully determines processing difficulty. Problematically for this claim, one local statistic, word frequency, has also been shown to affect processing, even when conditional probability given context is held constant. Here, we ask whether other local statistics have a role in processing, or whether word frequency is a special case. We present the first clear evidence that more complex local statistics, word bigram and trigram probability, also affect processing independently of surprisal. These findings suggest a significant and independent role of local statistics in processing. Further, it motivates research into new generalizations of surprisal that can also explain why local statistical information should have an outsized effect.