Language-related Brain Regions Research Articles

Language-related brain regions during “shiritori” task (Japanese capping verses): a spatial filtered MEG analysis

There is a Japanese traditional word game, “shiritori” (capping verses), analogous to English word generation. “Shiritori” task is characterized by demanding a subject to detect the phonetic factor of words as well as to generate words, and is expected to activate brain regions related to phonological processing, such as Wernicke's area. The aim of this study is to visualize neural activated brain regions during performance of a “shiritori” task using a MEG neuroimaging technique, Synthetic Aperture Magnetometry (SAM). Eight healthy right-handed, native Japanese speakers were studied. They gave their informed consents. Subjects were instructed to play “shiritori” by themselves silently during the “shiritori” task. In 8–25 Hz band, neural activated regions (corresponding to event-related desynchronization) were estimated in language-related brain regions with left-side dominancy: dorsolateral prefrontal cortex (DLPFC), post-inferior frontal gyrus (IFG), primary motor cortex, post-superior temporal gyrus (STG), visual cortex, inferior parietal lobule. The results suggest that the “shiritori” task requires neural activations in Wernicke's area more strongly when compared with verbal fluency paradigm and that this task can be used for assessing pathophysiology of diseases with dysfunction of Wernicke's area such as schizophrenia.

Neural correlates of syntactic transformations.

Many agrammatic aphasics have a specific syntactic comprehension deficit involving processing syntactic transformations. It has been proposed that this deficit is due to a dysfunction of Broca's area, an area that is thought to be critical for comprehension of complex transformed sentences. The goal of this study was to investigate the role of Broca's area in processing canonical and non-canonical sentences in healthy subjects. The sentences were presented auditorily and were controlled for task difficulty. Subjects were asked to judge the grammaticality of the sentences while their brain activity was monitored using event-related functional magnetic resonance imaging. Processing both kinds of sentences resulted in activation of language-related brain regions. Comparison of non-canonical and canonical sentences showed greater activation in bilateral temporal regions; a greater activation of Broca's area in processing antecedent-gap relations was not found. Moreover, the posterior part of Broca's area was conjointly activated by both sentence conditions. Broca's area is thus involved in general syntactic processing as required by grammaticality judgments and does not seem to have a specific role in processing syntactic transformations.

Grammaticality judgments on sentences with and without movement of phrasal constituents—an event-related fMRI study

One of the leading neurolinguistic theories of syntactic comprehension disorders in agrammatic aphasic subjects—the Trace Deletion Hypothesis—postulates a specific impairment in processing syntactic chains, and that this function is mediated by Broca's area. The aim of this study was to investigate whether the specific involvement of Broca's area in processing syntactic traces can be verified using functional brain imaging. We used event-related functional magnetic resonance imaging (fMRI) while healthy subjects were asked to judge the grammaticality of visually presented sentences with and without movement of phrasal constituents. During both kinds of sentences, fMRI showed activation in language-related brain regions. Comparing both kinds of sentences did not result in differential brain activation of left frontal or temporal regions. In particular, Broca's area was similarly activated in processing both moved and nonmoved sentences. Thus, Broca's area seems to be involved in general syntactic processing as required by grammaticality judgments rather than having a specific function in transmitting syntactic relations.

Premorbid speech and language impairments in childhood-onset schizophrenia: association with risk factors.

As both premorbid neurodevelopmental impairments and familial risk factors for schizophrenia are prominent in childhood-onset cases (with onset of psychosis by age 12), their relationship was examined. Premorbid language, motor, and social impairments were assessed in a cohort of 49 patients with childhood-onset schizophrenia. Familial loading for schizophrenia spectrum disorders, familial eye-tracking dysfunction, and obstetrical complications were assessed without knowledge of premorbid abnormalities and were compared in the patients with and without developmental impairments. Over one-half of the patients in this group had developmental dysfunction in each domain assessed. The patients with premorbid speech and language impairments had higher familial loading scores for schizophrenia spectrum disorders and more obstetrical complications, and their relatives had worse smooth-pursuit eye movements. The boys had more premorbid motor abnormalities, but early language and social impairments did not differ significantly between genders. There were no other significant relationships between premorbid social or motor abnormalities and the risk factors assessed here. Premorbid developmental impairments are common in childhood-onset schizophrenia. The rates of three risk factors for schizophrenia (familial loading for schizophrenia spectrum disorders, familial eye-tracking dysfunction, and obstetrical complications) were increased for the probands with premorbid speech and language impairments, suggesting that the pathophysiology of schizophrenia involves the abnormal development of language-related brain regions.

Ultrasonics makes ring welds: Iron Age, 193, No. 18, p. 140 (1964)

Glioblastoma (GBM) brain tumor is the most aggressive white matter (WM) invasive cerebral primary neoplasm. Due to its inherently heterogeneous appearance and shape, previous studies pursued either the segmentation precision of the tumors or qualitative analysis of the impact of brain tumors on WM integrity with manual delineation of tumors. This paper aims to develop a comprehensive analytical pipeline, called (TS)2WM, to integrate both the superior performance of brain tumor segmentation and the impact of GBM tumors on the WM integrity via tumor segmentation and tract statistics using the diffusion tensor imaging (DTI) technique. The (TS)2WM consists of three components: (i) A dilated densely connected convolutional network (D2C2N) for automatically segment GBM tumors. (ii) A modified structural connectome processing pipeline to characterize the connectivity pattern of WM bundles. (iii) A multivariate analysis to delineate the local and global associations between different DTI-related measurements and clinical variables on both brain tumors and language-related regions of interest. Among those, the proposed D2C2N model achieves competitive tumor segmentation accuracy compared with many state-of-the-art tumor segmentation methods. Significant differences in various DTI-related measurements at the streamline, weighted network, and binary network levels (e.g., diffusion properties along major fiber bundles) were found in tumor-related, language-related, and hand motor-related brain regions in 62 GBM patients as compared to healthy subjects from the Human Connectome Project.

Amoebiasis

When learning a new language, we build brain networks to process and represent the acquired words and syntax and integrate these with existing language representations. It is an open question whether the same or different neural mechanisms are involved in learning and processing a novel language compared with the native language(s). Here we investigated the neural repetition effects of repeating known and novel word orders while human subjects were in the early stages of learning a new language. Combining a miniature language with a syntactic priming paradigm, we examined the neural correlates of language learning on-line using functional magnetic resonance imaging. In left inferior frontal gyrus and posterior temporal cortex, the repetition of novel syntactic structures led to repetition enhancement, whereas repetition of known structures resulted in repetition suppression. Additional verb repetition led to an increase in the syntactic repetition enhancement effect in language-related brain regions. Similarly, the repetition of verbs led to repetition enhancement effects in areas related to lexical and semantic processing, an effect that continued to increase in a subset of these regions. Repetition enhancement might reflect a mechanism to build and strengthen a neural network to process novel syntactic structures and lexical items. By contrast, the observed repetition suppression points to overlapping neural mechanisms for native and new language constructions when these have sufficient structural similarities. <b>SIGNIFICANCE STATEMENT</b> Acquiring a second language entails learning how to interpret novel words and relations between words, and to integrate them with existing language knowledge. To investigate the brain mechanisms involved in this particularly human skill, we combined an artificial language learning task with a syntactic repetition paradigm. We show that the repetition of novel syntactic structures, as well as words in contexts, leads to repetition enhancement, whereas repetition of known structures results in repetition suppression. We thus propose that repetition enhancement might reflect a brain mechanism to build and strengthen a neural network to process novel syntactic regularities and novel words. Importantly, the results also indicate an overlap in neural mechanisms for native and new language constructions with sufficient structural similarities.