Assessing processes of learning Japanese as a second language with near-infrared topography (NIRS) and magnetoencephalography (MEG)

Yoko Okita, Ph.D.
International Student Center, Tokyo Medical and Dental University, Tokyo, Japan

Abstract:
This paper reports preliminary results of investigating Japanese language learning processes with NIRS and MEG and discusses potential of application of non-invasive brain imaging techniques in language learning. Participants were adult learners of Japanese as a second language (JSL) and adult Japanese native speakers. JSL learners in the current study were late elearners and their first languages varied.  NIRS measure changes inoxygenated haemoglobin and deoxygenated haemoglobin. Activation of the temporal lobes was measured with NIRS while participants decided whether an auditory presented word has long or short vowel.  The results varied greatly from individual to individual. Head hair and head movements easily caused artifacts.  NIRS can disclose cortical activities that other imaging techniques cannot present.  However, it is necessary to establish methods of analyzing NIRS data. MEG was used to investigate neural activities during visual kanji recognition tasks. The aim of this MEG study is comparing the amplitudes of the components of 100-200 (M170) ms after stimulus onset. It is appeared that the amplitudes of the M170 components for visual stimuli were bigger in Japanese and Chinese participants compared with other JSL learners whose first languages do not use Chinese characters. The amplitudes of the M170 components of a Japanese with poor visual discrimination scores were smaller compared with those of a Japanese with good visual discrimination scores.  The two Japanese participants are graduate students and are supposed to have good kanji knowledge and operational skills. This result suggests that neurological activities may not correlate with language proficiency.