Native Japanese Adults Research Articles

Comparing the beliefs regarding biological or psychological causalities toward stereotyped perception of people who stutter.

Developmental stuttering is a fluency disorder that may be caused by neurological, genetic, or familial factors. However, a general perception that stuttering is caused by psychological problems could lead to negative attitudes toward stuttering, causing prejudice or discrimination against people who stutter (PWS). Thus, our study aimed to investigate whether certain beliefs in etiology of stuttering are related to the negative perception of stuttering. A web-based survey of 413 native Japanese adults, aged 20-69, who did not suffer from stuttering, schizophrenia, or depression, was conducted in August 2021. The participants were recruited through the Web monitor panel. Participants were divided into three uniform groups based on their response to a 27-item questionnaire about their implicit belief regarding the etiology of stuttering: belief in the biological model (stuttering-biological group), belief in the psychological model (stuttering-psychological group), and the control group (those who responded to perception of healthy adult males). Participants were also asked to respond to 25 items of semantic differential scales about perception of stuttering or healthy adult males. Responses were summarized into several factors by factor analysis, and factor scores were compared among the three groups. The stuttering-biological group had the fewest participants, comprising 80 individuals. Overall, a total of 240 participants, 80 from each group, were included in the analysis. Some pairs of stereotypes included in semantic differential scales revealed differences between the groups; PWS, irrespective of the participants of the biological or psychological group, were considered as having negative stereotyping properties such as being "tense," "anxious," or "afraid." Additionally, three concepts from the factor analysis of these 25 items were analyzed using an analysis of variance, and significant differences were found; the mean factor score of the "danger" stereotype was lower in the stuttering-biological group compared to the stuttering-psychological group. Although the simplification of the biological model is not recommended, anti-stigma campaigns to educate people that stuttering is caused by multidimensional factors, not just psychological ones, could change the general public's negative perceptions of stuttering.

Adaptation and validation of the main concept analysis of spoken discourse by native Japanese adults

ABSTRACT Many people with aphasia demonstrate problems of oral production at the discourse level. The Main Concept Analysis (MCA) for oral discourse production is a published evidence-based battery for quantifying the degree of presence, accuracy, completeness, and efficiency of targeted main concepts in oral discourse. In Japan, such a standardized tool specialized for assessing spoken discourse is currently lacking. The purpose of this study was to adapt the Japanese version of MCA for oral discourse production (the Japanese-MCA) and examine its validity and reliability. Stage 1 of the study involved the establishment of linguistically-specific main concepts (MCs) of the Japanese-MCA. Ten speech-language-hearing therapists and 60 healthy participants who were native monolingual Japanese speakers were recruited to determine MCs. Stage 2 examined the criterion validity and reliability of the Japanese-MCA. Language samples of 20 participants with aphasia, as verified by Standard Language Test of Aphasia (SLTA), and 20 healthy older participants were used. Results of Stage 1 of the study yielded normative data with a set of target MCs that were geographically and linguistically specific for use in Japan. The results also revealed the comparability of the Japanese-MCA and previously reported versions of other languages. Stage 2 findings indicated not only a high correlation of criterion validity, but also good reliability of the test. With established norms and specific scoring criteria of the Japanese-MCA, it is believed that this new tool will become a useful addition to clinical management and research of aphasia in Japan.

An acoustic analysis of American English liquids by adults and children: Native English speakers and native Japanese speakers of English.

This study investigated acoustic characteristics of American English liquids produced by native English (NE) and native Japanese (NJ) speakers reported in Aoyama, Flege, Guion, Akahane-Yamada, and Yamada [(2004). J. Phonetics 32, 233-250]. For a larger longitudinal study, the data were collected twice to investigate the acquisition of American English by the NJ speakers (Time 1, Time 2). Aoyama, Flege, Guion, Akahane-Yamada, and Yamada [(2004). J. Phonetics 32, 233-250] evaluated productions of /l/ and /ɹ/ in the NE and NJ adults and children (16 participants each) using NE speakers' perceptual judgments and showed that the NJ children's production of /ɹ/ improved from Time 1 to Time 2. In the current study, four acoustic parameters (duration, F1, F2, and F3) were measured in 256 tokens each of English /l/ and /ɹ/. Results showed that some acoustic parameters, such as F2, changed from Time 1 to Time 2 in the NJ speakers' productions, indicating improvements. However, the NJ speakers' productions were different from the NE speakers' productions in almost all acoustic parameters at both Time 1 and Time 2. Results suggest that the improvements in the NJ children's productions of /ɹ/ reported in Aoyama, Flege, Guion, Akahane-Yamada, and Yamada [(2004). J. Phonetics 32, 233-250] were due to a combination of changes, not due to a change in one acoustic parameter such as F3 in /ɹ/.

Acoustical analysis of English /r/ and /l/ by native Japanese adults and children

This study investigated the acoustic properties of American English /r/ and /l/ produced by native Japanese (NJ) and native English (NE) speakers. The purpose of this study was to examine the differences in production reported in Aoyama et al. (2004) acoustically. Aoyama et al. evaluated productions of /r/ and /l/ in 64 NE and NJ adults and children (16 participants each in 4 groups) using intelligibility ratings. The data were collected twice to study the acquisition of English by the NJ adults and children. In this study, four acoustic parameters (duration, F1, F2, and F3) were measured in 256 tokens each of /r/ and /l/. The results showed that all of the acoustic parameters differed significantly between NJ and NE speakers at both times of testing. Some aspects of acoustic parameters changed significantly over the course of one year in NJ children’s productions. Lastly, the formant values in NJ speakers’ productions indicated that their productions of both /r/ and /l/ resembled NE speakers’ productions...

A one-year longitudinal study of English and Japanese vowel production by Japanese adults and children in an English-speaking setting

The effect of age of acquisition on first- and second-language vowel production was investigated. Eight English vowels were produced by Native Japanese (NJ) adults and children as well as by age-matched Native English (NE) adults and children. Productions were recorded shortly after the NJ participants' arrival in the USA and then one year later. In agreement with previous investigations [ Aoyama, Flege, Guion, Akahane-Yamada, & Yamada (2004). Journal of Phonetics, 32, 233–250], children were able to learn faster, leading to higher accuracy than adults in a year's time. Based on the spectral quality and duration comparisons, NJ adults had more accurate production at Time 1 but showed no improvement over time. The NJ children's productions, however, showed significant differences from the NE children's for English “new” vowels /ɪ/, /ɛ/, /ɑ/, /ʌ/ and /ʊ/ at Time 1 but produced all eight vowels in a native-like manner at Time 2. An examination of NJ speakers' productions of Japanese /i/, /a/, /u/ over time revealed significant changes for the NJ Child Group only. Japanese /i/ and /a/ showed changes in production that can be related to second language (L2) learning. The results suggest that L2 vowel production is affected importantly by age of acquisition and that there is a dynamic interaction, whereby the first and second language vowels affect each other.

Speech Perception in Quiet and Noise Using the Hearing in Noise Test and the Japanese Hearing in Noise Test by Japanese Listeners

The aim of this study was to evaluate the first-language (L1) and second-language (L2) perception abilities in quiet and noise of native Japanese listeners who acquired English late in life and lived in the United States. The study addressed two primary questions: (1) whether native Japanese listeners who developed some fluency in English showed poorer English speech perception ability in quiet and noise than native English listeners, and (2) whether native Japanese listeners living in an English-speaking environment demonstrated poorer speech perception ability in Japanese than native Japanese listeners who reside in Japan and rarely use a second language. Ten native Japanese adults who had excellent English word recognition ability in quiet were evaluated using the English and Japanese versions of the Hearing in Noise Test (HINT). In addition, 10 native English adults were evaluated using the English version of the HINT. All Japanese participants started learning English between the ages of 12 and 13 yrs while at school in Japan and had lived in the United States more than 4 yrs. An adaptive procedure was used to measure English and Japanese speech recognition thresholds (SRTs) in quiet and signal-to-noise ratios (SNRs) at which SRTs were obtained in noise conditions. In addition, a fixed-level procedure was used to obtain percent correct recognition scores at five different SNRs. Both HINT sentence stimuli and noise were presented at a simulated 0° azimuth under headphones. The Japanese group had significantly poorer English speech perception ability than the native English group in all the test conditions under both the adaptive and fixed-level procedures. The psychometric function for the Japanese listeners was shifted by approximately 3 to 4 dB SNR from that of the native English listeners. Japanese speech recognition ability by the Japanese group was not significantly different from that of native Japanese speakers who live in Japan. The Japanese participants who had excellent English word recognition ability in quiet listening conditions failed to reach native-like English speech perception when presented with sentences in quiet conditions. In addition, all 10 Japanese listeners examined in this study had HINT SNRs (i.e., SNRs at which SRTs were obtained in noise conditions) outside the normal range. However, the possible deterioration of L1 speech perception after living in the L2 environment for an extended period of time was not observed among the Japanese, late L2 learners in this study. The implication of this study for clinical settings is that it is important to use L1 sentence materials in both quiet and noise to examine the speech recognition performance of L2 (English) users who had acquired L2 after puberty.

Functional MRI evidence for the importance of visual short‐term memory in logographic reading

Logographic symbols are visually complex, and thus children's abilities for visual short-term memory (VSTM) predict their reading competence in logographic systems. In the present study, we investigated the importance of VSTM in logographic reading in adults, both behaviorally and by means of fMRI. Outside the scanner, VSTM predicted logographic Kanji reading in native Japanese adults (n=45), a finding consistent with previous observations in Japanese children. In the scanner, participants (n=15) were asked to perform a visual one-back task. For this fMRI experiment, we took advantage of the unique linguistic characteristic of the Japanese writing system, whereby syllabic Kana and logographic Kanji can share the same sound and meaning, but differ only in the complexity of their visual features. Kanji elicited greater activation than Kana in the cerebellum and two regions associated with VSTM, the lateral occipital complex and the superior intraparietal sulcus, bilaterally. The same regions elicited the highest activation during the control condition (an unfamiliar, unpronounceable script to the participants), presumably due to the increased VSTM demands for processing the control script. In addition, individual differences in VSTM performance (outside the scanner) significantly predicted blood oxygen level-dependent signal changes in the identified VSTM regions, during the Kanji and control conditions, but not during the Kana condition. VSTM appears to play an important role in reading logographic words, even in skilled adults, as evidenced at the behavioral and neural level, most likely due to the increased VSTM/visual attention demands necessary for processing complex visual features inherent in logographic symbols.

Investigating non‐native category learning using a video‐game‐based training paradigm.

Adults have difficulty learning non‐native speech categories, presenting an opportunity to study adult learning and plasticity with non‐native speech categorization. Long‐term training within laboratory‐based response‐feedback paradigms has produced modest non‐native category learning in previous studies. The current study investigates the effectiveness of a video‐game‐based categorization training paradigm, found to be effective in learning novel nonspeech auditory categories [W. Holt, (2005)], to train native Japanese adults to categorize English /r/ and /l/. This approach emphasizes functional associations between sound categories and players’ responses to video‐game characters rather than overt phonetic categorization. Although categorization is not explicit in the game it is helpful to overall performance, providing a functional and perhaps more ecologically valid training signal than traditional feedback in standard laboratory training procedures. Japanese participants who played the game for about 2.5 h across 5 days with /r/ and /l/ sounds matched to game characters showed more nativelike perception of English /r/ and /l/ than control participants who played the game with nonspeech sounds. Listeners’ categorization performance furthermore reflected regularities of the /r/‐/l/ input distributions. In particular, variability across second‐formant (F2) frequency may have encouraged listeners to shift perceptual cue weights toward more nativelike use of third formant (F3) frequency.

A longitudinal study of English and Japanese vowel production by Japanese adults and children in an English immersion setting.

The effect of age of acquisition on first‐ and second‐language vowel production was investigated. Eight English vowels were produced three times in two different words each by 16 native Japanese (NJ) adults and children as well as 16 age‐matched native English (NE) speaking adults. Productions were recorded shortly after the NJ participants’ arrival in the United States and then 1 year later. In agreement with previous investigations [Aoyama et al., J. Phonetics 32, 233–250 (2004)], children were able to learn faster, leading to higher accuracy than adults in a year’s time. Based on acoustic measurements, NJ adults had more accurate production at Time 1 but made no changes across time. The NJ children, on the other hand, showed significant differences from NE children’s productions for /ɪ/, /ε/, /ɑ/, /ʌ/, and /U/ at Time 1, but produced all eight vowels in a native‐like manner at Time 2. A follow up examination of NJ children’s productions of Japanese /i/, /a/, /u/ revealed significant changes for Japanese /i/ and /a/ related to L2 learning. The results suggest that L2 vowel production is heavily affected by age of acquisition and that there is a dynamic interaction between first‐ and second‐language vowels. [Work supported by NIH.]

Perceived phonetic dissimilarity and L2 speech learning: the case of Japanese /r/ and English /l/ and /r/

Previous research has demonstrated that English /r/ is perceptually more dissimilar from Japanese /r/ than English /l/ is for native Japanese (NJ) speakers. It has been proposed by the Speech Learning Model that the more distant an L2 sound (phonetic segment) is from the closest L1 speech sound, the more learnable the L2 sound will be (in: W. Strange (Ed.), Speech Perception and Linguistic Experience: Issues in Cross-language Research, York Press, Timonium, MD, 1995, p. 233). This hypothesis was evaluated in this study by investigating whether NJ speakers will have more success acquiring English /r/ than /l/. A longitudinal study examined the perception (Experiment 1) and production (Experiment 2) of English /l/, /r/, and/w/ by NJ adults and children who were living in the US at the time of testing. The results suggested that there was greater improvement for English /r/ than English /l/ among the NJ children. The NJ children's discrimination of /l/-/r/ and /r/-/w/ was significantly better at the second testing (T2) than 1 year earlier (T1). The NJ children also showed greater improvement from T1 to T2 in producing /r/ than /l/. The results are taken as support for a hypothesis of the Speech Learning Model (in: W. Strange (Ed.), Speech Perception and Linguistic Experience: Issues in Cross-language Research, York Press, Timonium, MD, 1995, p. 233) that degree of perceived phonetic dissimilarity influences L2 learners’ success in acquiring L2 phonetic segments.

Japanese adult’s and children’s production and perception of English fricatives: A longitudinal study

This study examined the production and perception of English fricatives by native Japanese (NJ) adults and children (16 per group, mean age=40 and 10 years), and age-matched native English (NE) adults and children (16 per group). The subjects were tested two times (T1, T2) 1 year apart. (At T1, the NJ subjects’ mean length of residence in the U.S. was 0.5 year.) A picture-naming task was used to elicit the production of English words beginning with /s/ and /θ/, and intelligibility scores were obtained for both. The intelligibility scores of the NJ children but not adults improved significantly from T1 to T2. The NJ children obtained significantly lower scores than the NJ adults did at T1, but at T2 the adult–child difference was nonsignificant. The perception of /s/ and /θ/ was tested by a categorial discrimination task. Although the NJ adult’s and children’s scores improved from T1 to T2, the T1–T2 differences were nonsignificant. Thus, the results showed that the NJ children’s production scores improved significantly from T1 to T2, while there was no significant change for the perception scores on the discrimination of /s/–/θ/. The relationship between production and perception in L2 speech learning will be discussed. [Work supported by NIH.]

Perception and production of English consonants by Japanese adults and children

This study examined perception and production of English consonants by native Japanese (NJ) adults and children (16 subjects in each group, mean age=39.9 and 9.9 years). The subjects were tested 2 times (T1, T2), when their mean lengths of residence in the U.S. were 0.5 years and 1.6 years. Age-matched native English (NE) controls (16 adults, 16 children) also participated. A categorial discrimination task was used to assess the perception of the English contrasts /b/–/s/, /b/–/v/, /ɹ/-/l/, /ɹ/–/w/, and /s/–/θ/. For three groups (NE adults, NE children, NJ adults), the T1 and T2 scores did not differ significantly on any contrast. The NJ children’s scores were significantly higher at T2 than at T1 on the /ɹ/–/l/ and /ɹ/–/w/ contrasts. A picture naming task with auditory cues were used to elicit the production of English words containing consonants of interest. Twelve NE listeners identified the subjects’ production of /ɹ/, /l/, and /w/ in word-initial position. Only the NJ children’s scores improved significantly from T1 to T2, and their improvement was the greatest on the production of /ɹ/. Several possible explanations will be offered for why there seems to be more improvement from T1 to T2 for /ɹ/ than /l/.

The acquisition of /r/ and /l/ by Japanese learners of English: Evidence that speech production can precede speech perception

ABSTRACTThis study examines the relationship between the production and perception of English /r/ and /l/ by native Japanese adults learning English in the United States. For some subjects, production of the contrast was more accurate than their perception of it, replicating and extending a previous finding reported by Goto (1971) in Japan. The difficulty in perception of the liquid contrast varied with its position in the word. Prevocalic /r/ and /l/ in consonant clusters yielded the greatest perceptual errors, while word-final liquids were accurately perceived. This pattern of errors is not predictable on the basis of contrastive phonological analysis, but might be the result of acoustic-phonetic factors. Implications for second language pedagogy are discussed.

Categorical perception of English /r/ and /l/ by Japanese bilinguals

ABSTRACTCategorical perception of a synthetic /r/-/l/ continuum was investigated with Japanese bilinguals at two levels of English language experience. The inexperienced Japanese group, referred to as Not-experienced, had had little or no previous training in English conversation. The Experienced Japanese group had had intensive training in English conversation by native American-English speakers. The tasks used were absolute identification, AXB discrimination, and oddity discrimination. Results showed classic Categorical perception by an American-English control group. The Not-experienced Japanese showed near-chance performance on all tasks, with performance no better for stimuli that straddled the /r/-/l/ boundary than for stimuli that fell in either category. The Experienced Japanese group, however, perceived /r/ and /l/ categorically. Their identification performance did not differ from the American-English controls, but their overall performance levels on the discrimination tests were somewhat lower than for the Americans. We conclude that native Japanese adults learning English as a second language are capable of Categorical perception of /r/ and /l/. Implications for perceptual training of phonemic contrasts are discussed.

Some secular changes in the growth of American‐born and native Japanese children

Three hundred and sixteen (35%) of the American-born Japanese children whose height, weight, and skeletal age were recorded in 1956-57 were reexamined as young adults between 1968 and 1974, when they were found to be taller, heavier and shorter legged than men and women in Japan who were born in the same years as they. These differences between the American-born and the native Japanese adults were relatively smaller than they had been during childhood, due to both an acceleration in the growth rate of the native Japanese and a concomitant decline in that of the American-born Japanese during the intervening years. A comparison of our 1956-57 data with Kondo and Eto's findings in Los Angeles in 1971 shows that there has been very little increase in the size of California-Japanese children since 1956. The curves of average heights of native Japanese children 6 to 20 years of age, at 10-year intervals from 1900 to 1970, disclosed the changing rate at which they grew during different decates of that period. Those curves and other data discussed in this paper provide additional evidence of the biological superiority of the human female as compared with the male.