Similarity-based interference during language comprehension: Evidence from eye tracking during reading.

The nature of working memory operation during complex sentence comprehension was studied using eye-tracking methodology. Readers had difficulty when the syntax of a sentence required them to hold two similar noun phrases (NPs) in working memory before syntactically and semantically integrating either of the NPs with a verb. In sentence structures that placed these NPs at the same linear distances from one another but allowed integration with a verb for one of the NPs, the comprehension difficulty was not seen. These results are interpreted as indicating that similarity-based interference occurs online during the comprehension of complex sentences and that the degree of memory accessibility conventionally associated with different types of NPs does not have a strong effect on sentence processing