Neural basis of sentence processing in which incoming words form a sentence

Electrophysiological evidence for a subject-first strategy in visually situated auditory sentence processing in Korean

This study investigated a subject-first strategy in prediction mechanism in visually situated sentence processing in Korean, using event-related potentials (ERPs). According to the subject-first strategy, parsers tend to generate sentences conforming to canonical sentence word order (i.e., SOV in Korean), subject-first sentence, mapping conceptually more prominent referent such as agent of the event on the subject position of the sentence. Therefore, in the predictive mechanism of language comprehension, the subject is pre-activated and anticipated for the first NP of the sentence at the initial phase of bottom-up language processing. This study tested this subject-first strategy in Korean by examining brain responses to object-initial sentences (OV) compared with subject-initial sentences (SV) under the context of clear thematic role relations set by a visual image. The results of an ERP experiment with 30 native Korean speakers identified neural effects for object-initial sentences compared with subject-initial sentences at the NP and Verb, reflecting a conflict between the pre-activated representation in the parser's mind and the encountered bottom-up input. An N400 effect was elicited at the NP, as early as at the noun, not at the following object case marker. Late frontal positivity (LFP) was also found in the sentence-final verb, proving the processing difficulty of non-canonical object-initial sentences compared with canonical subject-initial sentences. These results indicate that Korean native speakers build linguistic representation conforming to a canonical sentence in SOV language in the predictive mechanism supporting subject-first strategy but revise the predicted event structure rapidly upon newly encountering input.

Incremental Sentence Processing in Japanese: A Maze Investigation into Scrambled and Control Sentences

This study investigates preverbal structural and semantic processing in Japanese, a head-final language, using the maze task. Two sentence types were tested-simple scrambled sentences (Experiment 1) and control sentences (Experiment 2). Experiment 1 showed that even for simple, mono-clausal Japanese sentences, (1) there are online processing costs associated with parsing noncanonical word orders and (2) these costs are incurred during the incremental integration of constituents into developing sentence representations. Experiment 2 indicated (1) that antecedents are provisionally assigned to empty subjects in Japanese control sentences before verb information becomes available and (2) that this process is guided by an object control bias. Taken together, these findings are interpreted to suggest an important role for preverbal analysis in the processing of displaced constituents and of referential properties for empty elements in head-final languages.