Characteristics of Chinese-English bilingual dyslexia in right occipito-temporal lesion

Current literature suggests that right hemisphere lesions produce predominant spatial-related dyslexic error in English speakers. However, little is known regarding such lesions in Chinese speakers. In this paper, we describe the dyslexic characteristics of a Chinese-English bilingual patient with a right posterior cortical lesion. He was found to have profound spatial-related errors during his English word reading, in both real and non-words. During Chinese word reading, there was significantly less error compared to English, probably due to the ideographic nature of the Chinese language. He was also found to commit phonological-like visual errors in English, characterized by error responses that were visually similar to the actual word. There was no significant difference in visual errors during English word reading compared with Chinese. In general, our patient’s performance in both languages appears to be consistent with the current literature on right posterior hemisphere lesions. Additionally, his performance also likely suggests that the right posterior cortical region participates in the visual analysis of orthographical word representation, both in ideographical and alphabetic languages, at least from a bilingual perspective. Future studies should further examine the role of the right posterior region in initial visual analysis of both languages.     

Reading acquisition reorganizes the phonological awareness network only in alphabetic writing systems

It is unknown how experience with different types of orthographies influences the neural basis of oral language processing. In order to determine the effects of alphabetic and nonalphabetic writing systems, the current study examined the influence of learning to read on oral language in English and Chinese speakers. Children (8–12 years olds) and adults made rhyming judgments to pairs of spoken words during functional magnetic resonance imaging (fMRI). Developmental increases were seen only for English speakers in the left hemisphere phonological network (superior temporal gyrus (STG), inferior parietal lobule, and inferior frontal gyrus). The increase in the STG was more pronounced for words with conflicting orthography (e.g. pint‐mint; jazz‐has) even though access to orthography was irrelevant to the task. Moreover, higher reading skill was correlated with greater activation in the STG only for English speaking children. The effects suggest that learning to read reorganizes the phonological awareness network only for alphabetic and not logographic writing systems because of differences in the principles for mapping between orthographic and phonological representations. The reorganization of the auditory cortex may result in better phonological awareness skills in alphabetic readers. Hum Brain Mapp 34:3354–3368, 2013. © 2012 Wiley Periodicals, Inc.     

An investigation of semantic errors in unimpaired and Alzheimer's speakers of Italian

Semantic errors are a common type of slip of the tongue for normal speakers; they are also considered to be the hallmark of progressive diseases that affect semantic memory such as Alzheimer's Disease (AD) and semantic dementia. In unimpaired speakers, semantic errors have been shown to be affected by syntactic variables. For example, Marx (1999) has shown that speakers of a gendered language such as German tend to substitute a target with another word that shares the same grammatical gender with the target more often than chance would predict. This finding suggests that errors occur at a level at which lexical information about the target is activated and retrieved. Here, we assess whether such an effect of syntactic variables (gender) also holds in experimental tasks designed to induce errors in unimpaired speakers of Italian (another gendered language) and whether this effect can also be observed in the semantic errors produced in the same task by AD patients. We found that for the unimpaired speakers, the gender of the target word constrained the error committed, while this was not the case for the AD patients. We take this finding to suggest a different locus for the errors in the two populations: while the semantic errors by the unimpaired speakers occur because of mis-selection of a lexical entry due to lexical competition among semantically similar words, the errors by the AD patients occur because of insufficient activation of lexical representations.     

Intrusion errors in numerical transcoding by Alzheimer patients

The errors made by brain-damaged patients when they attempt numerical transcoding tasks have recently been considered as a possible aid to early diagnosis of the disease. The transcoding errors of 20 Alzheimer's disease patients are described, and the incidence of each kind of error compared with norms from healthy subjects. Tegnér and Nyb?ck (Tegnér R, Nyb?ck H. "To hundred and twenty4our": a study of transcoding in dementia. Acta Neurologica Scandinavia 1990; 81: 177-178) reported that Alzheimer patients often express numerical information in a mixture of verbal and digital codes and Kessler and Kalbe (Kessler J, Kalbe E. Written numerical transcoding in patients with Alzheimer's disease. Cortex 1996; 32: 755-761) suggested that such intrusions of the source code into the target code may not only be largely absent from the responses of the healthy population, but also from the transcoding operations of patients with other kinds of brain damage, such as aphasia. It was found that intrusion errors occurred much more frequently in the transcoding protocols of some of the Alzheimer patients than they do in those of healthy subjects. On the other hand, they were entirely absent from the protocols of other Alzheimer patients. The implications of the findings for the early diagnosis of Alzheimer's disease are discussed, and the phenomenon of intrusion errors is considered in terms of some of the models of arithmetical processing that have been proposed.     

Localized morphological brain differences between English-speaking Caucasians and Chinese-speaking Asians: new evidence of anatomical plasticity

Deformation field morphometry was applied to magnetic resonance images to detect differences in brain shape between English-speaking Caucasians and Chinese-speaking Asians. Anatomical differences between these two groups were limited to gyri in the frontal, temporal and parietal lobes, which are known (through functional imaging studies) to differentiate Chinese speakers from English speakers. We interpret these anatomical differences as evidence of neural plasticity shaped by the process of language acquisition during childhood. While anatomical plasticity due to manual skill acquisition (e.g. in musicians) has been established, to our knowledge this is the first report of a brain anatomical difference attributable to a learned cognitive strategy.     

Direct evidence from intraoperative electrocortical stimulation indicates shared and distinct speech production center between Chinese and English languages

Chinese processing has been suggested involving distinct brain areas from English. However, current functional localization studies on Chinese speech processing use mostly “indirect” techniques such as functional magnetic resonance imaging and electroencephalography, lacking direct evidence by means of electrocortical recording. In this study, awake craniotomies in 66 Chinese‐speaking glioma patients provide a unique opportunity to directly map eloquent language areas. Intraoperative electrocortical stimulation was conducted and the positive sites for speech arrest, anomia, and alexia were identified separately. With help of stereotaxic neuronavigation system and computational modeling, all positive sites elicited by stimulation were integrated and a series of two‐ and three‐dimension Chinese language probability maps were built. We performed statistical comparisons between the Chinese maps and previously derived English maps. While most Chinese speech arrest areas located at typical language production sites (i.e., 50% positive sites in ventral precentral gyrus, 28% in pars opercularis and pars triangularis), which also serve English production, an additional brain area, the left middle frontal gyrus (Brodmann's areas 6/9), was found to be unique in Chinese production (P < 0.05). Moreover, Chinese speakers’ inferior ventral precentral gyrus (Brodmann's area 6) was used more than that in English speakers. Our finding suggests that Chinese involves more perisylvian region (extending to left middle frontal gyrus) than English. This is the first time that direct evidence supports cross‐cultural neurolinguistics differences in human beings. The Chinese language atlas will also helpful in brain surgery planning for Chinese‐speakers. Hum Brain Mapp 36:4972–4985, 2015. © 2015 Wiley Periodicals, Inc.     

Simulated hearing loss and phrase dictation

The effect of simulated high frequency hearing loss in young adult speakers was examined. Subjects were native English speakers with normal hearing sensitivity. There were three listening conditions, two filtered conditions simulating high frequency hearing losses similar to those often occurring in the geriatric population and one unfiltered, or normal condition. Subjects listened to the Phrase Repetition subtest of the Boston Diagnostic Aphasia Examination. There were significant differences in the number of errors across the three conditions, with the most errors occurring during the greater simulated hearing loss. Such errors may be attributed to expressive language impairments when errors may instead be the result of a high frequency hearing loss.     

Evaluation of speech errors in Putonghua speakers with cleft palate: A critical review of methodology issues

Speech errors associated with cleft palate are well established for English and several other Indo-European languages. Few articles describing the speech of Putonghua (standard Mandarin Chinese) speakers with cleft palate have been published in English language journals. Although methodological guidelines have been published for the perceptual speech evaluation of individuals with cleft palate, there has been no critical review of methodological issues in studies of Putonghua speakers with cleft palate. A literature search was conducted to identify relevant studies published over the past 30 years in Chinese language journals. Only studies incorporating perceptual analysis of speech were included. Thirty-seven articles which met inclusion criteria were analyzed and coded on a number of methodological variables. Reliability was established by having all variables recoded for all studies. This critical review identified many methodological issues. These design flaws make it difficult to draw reliable conclusions about characteristic speech errors in this group of speakers. Specific recommendations are made to improve the reliability and validity of future studies, as well to facilitate cross-center comparisons.     

Assessing syntactic deficits in Chinese Broca’s aphasia using the Northwestern Assessment of Verbs and Sentences-Chinese (NAVS-C)

Background: English-speaking patients with Broca’s aphasia and agrammatism evince difficulty with complex grammatical structures, including verbs and sentences. A few studies have found similar patterns among Chinese-speaking patients with Broca’s aphasia, despite structural differences between these two languages. However, no studies have explicitly examined verb properties, including the number and optionality of arguments (participant roles) selected by the verb, and only a few studies have examined sentence deficits among Chinese patients. In addition, there are no test batteries presently available to assess syntactically important properties of verbs and sentences in Chinese patients.

Aims: This study used a Chinese version of the Northwestern Assessment of Verbs and Sentences (NAVS), originally developed for English speakers with aphasia, to examine the verb and sentence deficit patterns among Chinese speakers with aphasia. As in the original NAVS, the Chinese version (NAVS-C) assessed verbs by the number and optionality of arguments as well as sentence canonicity, in the both production and comprehension.

Methods and Procedures: Fifteen Chinese patients with Broca’s aphasia and 15 age-matched healthy normal controls participated in this study. All NAVS-C tests were administered, in which participants were asked either to produce or to identify verbs and sentences coinciding with action pictures.

Outcomes & Results: Despite grammatical differences between Chinese and English, the impairment caused by the structural complexity of verbs and sentences was replicated in Chinese-speaking patients using the NAVS-C. Verbs with more arguments were significantly more impaired than those with fewer arguments and verbs with optional arguments were significantly more impaired than those with obligatory arguments. One deviation from English-speaking patients, however, is that the Chinese-speaking patients exhibited greater difficulty with subject relative clauses than with object relative clauses because the former, rather than the latter, involve noncanonical order in Chinese. Similar to English-speaking patients, Chinese patients exhibited more difficulty with object-extracted wh-questions than with subject-extracted wh-questions, suggesting that wh-movement in Logical Form may also cause processing difficulty. Moreover, Chinese-speaking patients exhibited similar performance in both production and comprehension, indicating the deficits in both modalities.

Conclusions: The number and optionality of verb arguments as well as the canonicity of the Agent–Theme order in sentences impact Chinese-speaking individuals with aphasia as they do in the case of English-speaking patients. These findings indicate that the NAVS-C is a useful tool for detailing deficit patterns associated with syntactic processing in patients with aphasia cross-linguistically.     

Encoding,memory, and transcoding deficits in Childhood Apraxia of Speech

A central question in Childhood Apraxia of Speech (CAS) is whether the core phenotype is limited to transcoding (planning/programming) deficits or if speakers with CAS also have deficits in auditory-perceptual encoding (representational) and/or memory (storage and retrieval of representations) processes. We addressed this and other questions using responses to the Syllable Repetition Task (SRT) [Shriberg, L. D., Lohmeier, H. L., Campbell, T. F., Dollaghan, C. A., Green, J. R., & Moore, C. A. (2009). A nonword repetition task for speakers with misarticulations: The syllable repetition task (SRT). Journal of Speech, Language, and Hearing Research, 52, 1189–1212]. The SRT was administered to 369 individuals in four groups: (a) typical speech–language (119), (b) speech delay–typical language (140), (c) speech delay–language impairment (70), and (d) idiopathic or neurogenetic CAS (40). CAS participants had significantly lower SRT competence, encoding, memory, and transcoding scores than controls. They were 8.3 times more likely than controls to have SRT transcoding scores below 80%. We conclude that speakers with CAS have speech processing deficits in encoding, memory, and transcoding. The SRT currently has moderate diagnostic accuracy to identify transcoding deficits, the signature feature of CAS.     

Characteristics of dyslexia and dysgraphia in a Chinese patient with semantic dementia

We describe a 44-year-old Chinese-speaking patient with semantic dementia (SD), who demonstrates dyslexia and dysgraphia. The man was administered a series of neuropsychological inspections, including general language tests and reading and writing examinations. The patient demonstrated surface dyslexia when reading single Chinese characters aloud. While most writing errors demonstrated by the patient were orthographically similar errors and noncharacter responses, such as pictograph, logographeme, and stroke errors, rather than phonologically plausible errors that were homophonous or different only in tone from the targets. We suggest that the type of acquired dysgraphia demonstrated by Chinese-speaking SD patients is determined by the unique features of the Chinese writing system.     

Encoding, memory, and transcoding deficits in Childhood Apraxia of Speech

A central question in Childhood Apraxia of Speech (CAS) is whether the core phenotype is limited to transcoding (planning/programming) deficits or if speakers with CAS also have deficits in auditory-perceptual encoding (representational) and/or memory (storage and retrieval of representations) processes. We addressed this and other questions using responses to the Syllable Repetition Task (SRT) [Shriberg, L. D., Lohmeier, H. L., Campbell, T. F., Dollaghan, C. A., Green, J. R., & Moore, C. A. (2009). A nonword repetition task for speakers with misarticulations: The syllable repetition task (SRT). Journal of Speech, Language, and Hearing Research, 52, 1189-1212]. The SRT was administered to 369 individuals in four groups: (a) typical speech-language (119), (b) speech delay-typical language (140), (c) speech delay-language impairment (70), and (d) idiopathic or neurogenetic CAS (40). CAS participants had significantly lower SRT competence, encoding, memory, and transcoding scores than controls. They were 8.3 times more likely than controls to have SRT transcoding scores below 80%. We conclude that speakers with CAS have speech processing deficits in encoding, memory, and transcoding. The SRT currently has moderate diagnostic accuracy to identify transcoding deficits, the signature feature of CAS.     

Cognitive processing in Chinese literate and illiterate subjects: an fMRI study

Functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) were used to map brain activation during language tasks. While previous studies have compared performance between alphabetic literate and illiterate subjects, there have been no such data in Chinese-speaking individuals. In this study, we used fMRI to examine the effects of education on neural activation associated with silent word recognition and silent picture-naming tasks in 24 healthy right-handed Chinese subjects (12 illiterates and 12 literates). There were 30 single Chinese characters in the silent word recognition task and 30 meaningful road-signs in the silent picture-naming task. When we compared literate and illiterate subjects, we observed education-related differences in activation patterns in the left inferior/middle frontal gyrus and both sides of the superior temporal gyrus for the silent word recognition task and in the bilateral inferior/middle frontal gyrus and left limbic cingulated gyrus for the silent picture-naming task. These results indicate that the patterns of neural activation associated with language tasks are strongly influenced by education. Education appears to have enhanced cognitive processing efficiency in language tasks.     

An ERP study of continuous speech processing. II. Segmentation,semantics, and syntax in non-native speakers

Behavioral and electrophysiological studies indicate that altered language experience has different effects on distinct subsystems within language. In this study, we recorded event-related potentials (ERPs) in native Japanese late-learners of English listening to English sentences. ERP indices of semantic processing, syntactic processing, and speech segmentation were compared and contrasted for native Japanese and previously tested native English speakers. Native and non-native speakers showed similar semantic processing effects including an N400 for words as opposed to nonwords. In contrast, native Japanese speakers showed none of the effects associated with syntactic processing in native English speakers including an anterior negativity to nonwords presented in a syntactic context. Furthermore, the ERP word-onset effect evident in native English speakers was not found for the native Japanese speakers in this study. These data contribute additional and specific evidence to the proposal that subsystems within language display varying degrees of plasticity.     

Lexical influences on single word repetition in acquired spoken output impairment: A cross language comparison

Background: Among the many factors that may affect speech production, phonological neighbourhood density (ND) and phonotactic probability (PROB) have displayed effects on speech and language performance in healthy speakers. What is not clear is if they show an effect in impaired speech output after stroke and if they do, whether this effect is facilitatory or inhibitory.

Aims: To determine whether ND and/or PROB play a role in speech production accuracy in acquired output impairment after stroke. To compare the performance of English vs German speakers on a matched set of words in order to tease out language‐specific and language‐independent factors affecting impaired speech output.

Methods & Procedures: Seven English and seven German native speakers with acquired output impairment after stroke repeated in their respective languages 509 real words that are (near) homophones across German and English (e.g., leader–Lieder; vine–Wein). Responses were transcribed phonetically and scored as correct or incorrect.

Results & Outcomes: There was a small correlation between accuracy on near‐homophones between English and German speakers (r = .201; p < .001). Correlating accuracy for speakers combined across both languages with language‐independent factors (i.e., number of phonemes, syllables, clusters) showed significant independent effects of number of phonemes and clusters in the target, but multiple regressions did not show an effect of number of syllables. Within‐language correspondence was greater than between‐language correspondence (9.4% vs 4%; p < .00001). Correlating differences in accuracy in English/German with differences in language‐specific factors (i.e., word and syllable frequency, PROB, ND) multiple regression displayed a significant independent effect of the target's word frequency but not of the target's ND, PROB, or syllable frequency.

Conclusions: The small but significant correlation between accuracy on (near) homophones for English and German speakers suggests there are language‐independent determinants of production accuracy, whereas greater within‐language correspondence indicates language‐specific determinants of performance. Only word frequency appears to have a significant (facilitatory) effect on response accuracy. Neither ND nor PROB had a significant effect on response accuracy in this study. The results are discussed in light of theoretical and methodological issues within the study.     

Keeping track of a conversation: Impairments in Alzheimer's disease

Earlier research suggests that AD patients tend to be particularly impaired in the central executive component of working memory, leading to problems in coordinating information from different sources. This suggests that they may be particularly handicapped in keeping track of conversations involving several people. This was studied in 19 AD and 19 matched control subjects. The patients were screened to minimize problems of face recognition and language comprehension and were then shown videotapes of conversations involving from two to five characters. After each tape, a statement made by one of the characters was presented and the subject required to point to the person who had made that statement. Performance was at ceiling for normals, except when the speakers had changed location, when some errors occured. AD patients showed a clear tendency for performance to deteriorate as number of speakers increased, and to show higher error rates when participants changed location. Implications are discussed for AD patients attempting to cope with everyday social situations.     

Neural systems of second language reading are shaped by native language

Reading in a second language (L2) is a complex task that entails an interaction between L2 and the native language (L1). To study the underlying mechanisms, we used functional magnetic resonance imaging (fMRI) to visualize Chinese-English bilinguals' brain activity in phonological processing of logographic Chinese and alphabetic English, two written languages with a sharp contrast in phonology and orthography. In Experiment 1, we found that phonological processing of Chinese characters recruits a neural system involving left middle frontal and posterior parietal gyri, cortical regions that are known to contribute to spatial information representation, spatial working memory, and coordination of cognitive resources as a central executive system. We assume that the peak activation of this system is relevant to the unique feature of Chinese that a logographic character has a square configuration that maps onto a monosyllabic unit of speech. Equally important, when our bilingual subjects performed a phonological task on English words, this neural system was most active, whereas brain areas mediating English monolinguals' fine-grained phonemic analysis, as demonstrated by Experiment 2, were only weakly activated. This suggests that our bilingual subjects were applying their L1 system to L2 reading and that the lack of letter-to-sound conversion rules in Chinese led Chinese readers to being less capable of processing English by recourse to an analytic reading system on which English monolinguals rely. Our brain imaging findings lend strongest support to the idea that language experience tunes the cortex.     

Auditory identification of frequency-modulated sweeps and reading difficulties in Chinese

BackgroundIn Chinese Mandarin, lexical tones play an important role of providing contrasts in word meaning. They are pitch patterns expressed by frequency-modulated (FM) signals. Yet, few studies have looked at the relationship between low-level auditory processing of frequency signals and Chinese reading skills.AimsThe study aims to identify the role of auditory frequency processing in Chinese lexical tone awareness as well as character recognition in Chinese-speaking children.MethodsChildren with (N = 28) and without (N = 27) developmental dyslexia (DD) were recruited. All participants completed two linguistic tasks, Chinese character recognition and lexical tone awareness, and two auditory frequency processing tasks, frequency discrimination and FM sweep direction identification.ResultsThe results revealed that Chinese-speaking children with DD were significantly poorer at all tasks. Particularly, Chinese character recognition was significantly related to FM sweep identification. Lexical tone awareness was significantly associated with both auditory frequency processing tasks. Regression analyses suggested the influence of FM sweep identification on Chinese character recognition contributed through lexical tone awareness.Conclusions and implicationThis study suggests that poor auditory frequency processing may associate with Chinese developmental dyslexia with phonological deficits. In support of the phonological deficit hypothesis, what underlies phonological deficit is likely to be auditory-basis. A potential clinical implication is to reinforce auditory perception and sensitivity through intervention for phonological processing.