Dialectal differences in hemispheric specialization for Japanese lexical pitch accent Yutaka Sato a,b,⇑ , Akira Utsugi a,c,d , Naoto Yamane a , Masatoshi Koizumi e , Reiko Mazuka a,f a Lab. for Language Development, BSI, RIKEN, Wako, Saitama, Japan b Institute of Socio-Arts and Sciences, University of Tokushima, Tokushima, Japan c Faculty of Humanities and Social Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan d Graduate School of Languages and Cultures, Nagoya University, Nagoya, Japan e Department of Linguistics, Tohoku University, Sendai, Miyagi, Japan f Department of Psychology & Neuroscience, Duke University, Durham, NC, USA article info Article history: Accepted 21 September 2013 Available online 16 October 2013 Keywords: Cerebral lateralization Lexical pitch accent Near Infrared Spectroscopy (NIRS) Dialect abstract Language experience can alter perceptual abilities and the neural specialization for phonological con- trasts. Here we investigated whether dialectal differences in the lexical use of pitch information lead to differences in functional lateralization for pitch processing. We measured cortical hemodynamic responses to pitch pattern changes in native speakers of Standard (Tokyo) Japanese, which has a lexical pitch accent system, and native speakers of ‘accentless’ dialects, which do not have any lexical tonal phe- nomena. While the Standard Japanese speakers showed left-dominant responses in temporal regions to pitch pattern changes within words, the accentless dialects speakers did not show such left-dominance. Pitch pattern changes within harmonic-complex tones also elicited different brain activation patterns between the two groups. These results indicate that the neural processing of pitch information differs depending on the listener’s native dialect, and that listeners’ linguistic experiences may further affect the processing of pitch changes even for non-linguistic sounds. Ó 2013 Elsevier Inc. All rights reserved. 1. Introduction A native speaker of a language possesses an intricate knowledge of that language’s phonological system, including its unique set of phonemic categories, phonological rules and prosodic structures. Recent advances in brain imaging studies have begun to reveal the neural processes involved in processing certain types of phono- logical information. In particular, it has been shown that the left and right cerebral hemispheres work differently for processing segmental and prosodic aspects of phonology: the left hemisphere is more heavily involved in processing segmental contrasts while the right hemisphere typically processes prosodic cues including affective prosody (Buchanan et al., 2000; Jacquemot, Pallier, LeBihan, Dehaene, & Dupoux, 2003; Näätänen et al., 1997; Ross, 1981; Schirmer & Kotz, 2006; Tervaniemi et al., 1999; van Lancker, 1980; Zatorre, Evans, Meyer, & Gjedde, 1992). The neural processing of language, however, can be substan- tially altered by one’s experience with a language, such as the age that one acquires it, and how much one uses it (c.f., Dehaene et al., 1997; Perani et al., 1998). Behaviorally, it is well established that as a consequence of learning one first language (L1), discrim- ination of segments in a non-native language (L2) becomes more difficult (e.g., English /r/ and /l/ by Japanese listeners; Goto, 1971; Miyawaki et al., 1975). Electrophysiological studies have shown that when native and non-native phonemic contrasts are compared, contrasts in one’s native language typically produce larger responses in the left auditory area, while non-native contrasts do not produce such responses (Buchwald, Guthrie, Schwafel, Erwin, & Van Lancker, 1994; Dehaene-Lambertz, 1997; Näätänen et al., 1997; Rivera-Gaxiola, Csibra, Johnson, & Karmiloff-Smith, 2000). The effects of language experience on hemispheric lateraliza- tion have been most clearly demonstrated with lexical-level pros- ody, such as tones in Thai or Chinese, and lexical pitch accent in Japanese. That is because acoustic cues that are prosodic (e.g., pitch changes), a characteristic that is generally associated with bilateral processing or a right-hemisphere advantage, are used to distin- guish lexical meaning, which is associated with a left-hemisphere advantage. In Japanese, for example, a pair of homophones with two syllables may be distinguished by a pitch accent contour of high-to-low (HL) vs. low-to-high (LH): ha’shi (HL: ‘‘chop stick’’) vs. ha-shi’ (LH: ‘‘bridge’’). Brain activation for these stimuli seems 0093-934X/$ - see front matter Ó 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.bandl.2013.09.008 ⇑ Corresponding author. Address: Lab. for Language Development, BSI, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. Fax: +81 48 467 9760. E-mail addresses: satoyu@brain.riken.jp (Y. Sato), utsugi@lang.nagoya-u.ac.jp (A. Utsugi), yamanen@brain.riken.jp (N. Yamane), koizumi@sal.tohoku.ac.jp (M. Koizumi), mazuka@brain.riken.jp (R. Mazuka). Brain & Language 127 (2013) 475–483 Contents lists available at ScienceDirect Brain & Language journal homepage: www.elsevier.com/locate/b&l