An event-related fNIRS investigation of Japanese word order.

Japanese is a free word-order language, and allows both subject-object-verb (SOV) and object-subject-verb (OSV) orders. Our previous study using near-infrared spectroscopy (NIRS) imaging revealed that OSV sentences induce more activation in the left frontal lobe than SOV sentences. The present study develops our previous experiment: (1) by adopting an event-related design, and (2) by using sentences involving the adverb naze 'why', which plays a prominent role in recent linguistic studies.

A functional near-infrared spectroscopy study on the basic word order in Japanese.

To determine the basic word order in Japanese, oxyhemoglobin concentration changes in the frontal region of 32 healthy men were measured by near-infrared spectroscopy. Our experiment used four types of sentences: (i) subject-object-verb (SOV), (ii) object-subject-verb (OSV), (iii) subject-naze (why)-object-verb (SwhyOV), and (iv) naze (why)-subject-object-verb (whySOV). The results have shown that although oxyhemoglobin changes in the OSV sentences were significantly larger than those in the SOV sentences in the left frontal lobe, such effects were not observed between SwhyOV sentences and whySOV sentences.