Production, management and auditory brain perception of Japanese accentuation by non-native speakers of Japanese

This study reports on Japanese accentuation by non-native speakers (NNSs) of Japanese from the viewpoints of second language acquisition and implicit brain perception. The major focus was on the interlanguage strategies in their production of accentuation, their style-shifting of accentuation in comparison with that of Ibaraki dialect speakers (IBSs) of Japanese, their language management study of accentuation and the automatic brain perception of auditory accent patterns. The study used two major methods. One involved analyses of each participant's accentuation in natural discourse data, which is different from the general research on accentuation which focuses on the distinct use of an individual word. The second method involved examination of participants' brainwaves as measured without participants' attention to the stimulus sound of accent patterns, after which the mismatch negativity component (MMN) was analysed. The MMN provides the possibility of examining automatic brain responses to the auditory pitch patterns of accentuation. First, NNS participants' production of accentuation in discourse was investigated. Three types of interlanguage strategies (ILSs) of accentuation appeared to be produced on the basis of L2 norms, showing three developmental stages as well as free variations without conscious attention to the accentuation. On the other hand, participants also demonstrated the application of antepenultimate accent strategies and compound accent strategies, which appeared to be produced on the basis of universal norms. Thus, the accentuation of the same participants in the same discourse showed overlapping strategies on the basis of both the L2 and universal norms. Second, the style-shifting of accentuation between formal and informal situations is analysed and compared with that of the IBSs, who produce interdialect strategies (lOSs) showing strong resemblance to ILSs by NNSs of Japanese. It was found that both the NNSs and the Ibaraki dialect speakers showed systematic style-shifting of accentuation without explicit attention, although their style-shifting showed distinctly different characteristics. Third, since language management involves explicit conscious processes, the question of whether NNSs manage their accentuation in discourse is analysed on the basis of follow-up interviews. The following finding was observed: two of 11 participants managed their accentuation explicitly, although most of their management did not proceed to the implementation stage, and therefore, it was considered to be 'weak management'. It is presumed that they began to manage their accentuation, then stopped during the process and finally subconsciously produced ILSs. Lastly, the implicit processing of the two types of accentual pitch patterns in the brains of both NNS and NS participants was investigated by means of brainwave measurement, and the MMN was analysed. The results revealed the implication that both the NNSs and NSs implicitly noted accent patterns, and the unaccented pattern LHH was likely to be responded to as unnatural by both NNSs and NSs, presumably due to the influence of the pitch downtrend phenomenon observed in many languages. The results of this study, particularly the participants' implicit observations and the distinction of accent patterns in their brains, provide theoretical implications for studies on Japanese accentuation in SLA and neuronal correlates of pitch patterns in neuroscience, for example, the levelling of accent like 'specialists' accentuation' appears to be caused by the brain response to the feature of 'unnaturalness' of unaccented pattern. The discourse analyses also suggest new findings related to the influence of universal norms on the production of strategies for second language acquisition. The application of the findings to the teaching of accentuation in Japanese language education is also discussed.