Testing limits: ERP evidence for word form preactivation during speeded sentence reading.

While it is commonly agreed upon that language comprehenders preactivate information at multiple levels, there is less consensus regarding what and when information is predicted, under which circumstances, and via which mechanism(s). Regarding when, Ito, Corley, Pickering, Martin, & Nieuwland (2016) concluded that during sentence processing, word form-unlike semantic-preactivation crucially relies on the time available to generate late-stage predictions via language production mechanisms, setting this limit between 500 and 700 ms/word. The current event-related brain potential (ERP) study tests this proposal at a substantially faster serial visual presentation (SVP) rate of four words/s, on par with normal reading. We utilize the experimental design and replicate the general ERP findings of the two words/s SVP study of DeLong, Chan, & Kutas (2019), with results showing similar N400 reductions to unpredictable sentence continuations whether semantically or orthographically related to contextually predictable words, as well as an increased late posterior positivity to orthographic neighbors. These findings indicate that processing of written word information can be rapidly facilitated through context-based expectancies, establishing that if there is a time constraint for word form preactivation, it must be far less than limits specified by the prediction-by-production comprehension model championed by Ito et al.