The transposed-word effect does not require parallel word processing: Failure to notice transpositions with serial presentation of words

Readers sometimes fail to notice word transposition errors, reporting a sentence with two transposed words to be grammatical (the transposed-word effect). It has been suggested that this effect implicates parallel word processing during sentence reading. The current study directly assessed the role of parallel word processing in failure to notice word transposition errors, by comparing error detection under normal sentence presentation conditions and when words are presented serially at 250 ms/word. Extending recent results obtained with serial presentation of Chinese sentences (Liu, Li, Cutter, Paterson, & Wang, Cognition 218: 104922, 2022), in Experiment 1 we found a transposed-word effect with serial presentation of English sentences. In Experiment 2, we replicated this finding with task instructions that allowed responding at any time during the presentation of the sentence; this result indicates that the transposed-word effect that appears with serial word presentation is not due to a late process of reconstruction of short-term memory. Thus, parallel word processing is not necessary for a transposed-word effect in English. Like Liu et al. (2022), we did find that the transposed-word effect was statistically larger with parallel presentation than with serial presentation; we consider several explanations as to why this is so.