Pre- and post-head phrasal parsing of canonical and scrambled Japanese active sentences measured by the eye-tracking method

The present study used the eye-tracking method, measuring both pre- and post-head (before and after encountering a verb) phrasal pass gaze durations to investigate the processing of simple Japanese sentences, both canonical and scrambled in nature. Eighteen native Japanese speakers participated in the present experiment. Three types of 30 syntactically and semantically correct active sentences with ditransitive verbs were used: namely, (1) canonical [_S NP-ga [_VP NP-o [_V’ NP-ni V]]], (2) single-scrambled [_S NP-ga [_VP NP-o₁ [_VP NP-ni [_V' gap₁ V]]]] and (3) double-scrambled order [_S NP-o₁ [_S NP-ni₂ [_S NP-ga [_VP gap₂ [_V’ gap₁ V]]]]] (–ga refers to nominative case-markers, –o to accusative case-markers and –ni to dative case-markers). The results suggest that single-scrambled sentences containing a single filler-gap dependency in the third noun phrase can be processed by pre-head parsing, while double-scrambled sentences containing two filler-gap dependencies in the third phrase cannot be processed without seeing a head verb.