For example, ni works not only as a the dative case marker but also as a semantic case marker (e.g., locative; Sadakane and Koizumi 1995). Hence, it has been assumed that ni shows different behavior from nominative ga
and accusative o cases during sentence comprehension (Yokoyama et al. 2012a). Therefore, we predicted that the Japanese case particles ga and o would be associated with a similar pattern of brain activity, while ni would be associated with a different pattern. In order to test this hypothesis, we conducted a neuroimaging experiment designed to elucidate the processing differences among each Japanese case particle. #citation keyword# The stimuli in Inui et al. (2007) were used in order to exclude the effect of nouns, verbs, or
other sentential context. Material and Methods Participants Thirty-three native speakers of Japanese (18 men and 15 women; aged 19–35 years; mean age = 22.3 years) participated in this Inhibitors,research,lifescience,medical study. All participants were right-handed, as confirmed by the Edinburgh Handedness Inventory (Oldfield 1971). None of the participants reported any previous history of medical diseases. Written informed consent was obtained from each subject in accordance with Inhibitors,research,lifescience,medical the guidelines of Tohoku University Medical School, and the Helsinki Declaration of Human Rights (1975). Eight participants’ data were excluded from analysis because of lower accuracy rates on target items (85% or lower on each target item used in the analysis [see Data Analysis]). Stimuli and task procedure In this experiment, in order to set the context for a noun phrase, “X” followed by a single Japanese character (hiragana) was presented
visually on a screen. Japanese is a head-final language in which a case is marked by a case particle system and all nouns Inhibitors,research,lifescience,medical are followed by case particles. In the hiragana writing system, the basic timing unit is called “mora,” and each mora takes equal time to pronounce. A single hiragana can represent a consonant and vowel or a vowel only. Target items were three case particles: Inhibitors,research,lifescience,medical ga (nominative case), o (accusative case), and ni (dative case). Non-particles were presented (“u,” “nu,” “bu,” “za,” “ki,” “ro”) as filler items. The target experimental condition involved a particle judgment task in which participants were required to judge whether the character following “X” was a particle. This task was similar to that used in Inui et al. (2007). Brefeldin_A The control condition involved a phonological judgment task in which participants were required to judge whether the character following “X,” when spoken ended with the vowel sound [u]. In this task, participants were instructed to focus on only the phonological nature of the stimulus, so that activation associated with case particle processing could be determined by subtracting phonological judgment task-affiliated activation from particle judgment task-affiliated activation.