1101
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Abstract
The left parietal lobe has been proposed as a major language area. However, parietal cortical function is more usually considered in terms of the control of actions, contributing both to attention and cross-modal integration of external and reafferent sensory cues. We used positron emission tomography to study normal subjects while they overtly generated narratives, both spoken and written. The purpose was to identify the parietal contribution to the modality-specific sensorimotor control of communication, separate from amodal linguistic and memory processes involved in generating a narrative. The majority of left and right parietal activity was associated with the execution of writing under visual and somatosensory control irrespective of whether the output was a narrative or repetitive reproduction of a single grapheme. In contrast, action-related parietal activity during speech production was confined to primary somatosensory cortex. The only parietal area with a pattern of activity compatible with an amodal central role in communication was the ventral part of the left angular gyrus (AG). The results of this study indicate that the cognitive processing of language within the parietal lobe is confined to the AG and that the major contribution of parietal cortex to communication is in the sensorimotor control of writing.
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Affiliation(s)
- Sonia L E Brownsett
- Division of Neuroscience and Mental Health and Medical Research Council Clinical Sciences Centre, Imperial College, Hammersmith Campus, Du Cane Road, London W12 0NN, UK.
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1102
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Eickhoff SB, Heim S, Zilles K, Amunts K. A systems perspective on the effective connectivity of overt speech production. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2009; 367:2399-421. [PMID: 19414462 PMCID: PMC3268212 DOI: 10.1098/rsta.2008.0287] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The aim of this study was to provide a computational system model of effective connectivity in the human brain underlying overt speech production. Meta-analysis of neuroimaging studies and functional magnetic resonance imaging data acquired during a verbal fluency task revealed a core network consisting of Brodmann's area (BA) 44 in Broca's region, anterior insula, basal ganglia, cerebellum, premotor cortex (PMC, BA 6) and primary motor cortex (M1, areas 4a/4p). Dynamic causal modelling (DCM) indicated the highest evidence for a system architecture featuring the insula in a serial position between BA 44 and two parallel nodes (cerebellum/basal ganglia), from which information converges onto the PMC and finally M1. Parameter inference revealed that effective connectivity from the insular relay into the cerebellum/basal ganglia is primarily task driven (preparation) while the output into the cortical motor system strongly depends on the actual word production rate (execution). DCM hence allowed not only a quantitative characterization of the human speech production network, but also the distinction of a preparatory and an executive subsystem within it. The proposed model of physiological integration during speech production may now serve as a reference for investigations into the neurobiology of pathological states such as dysarthria and apraxia of speech.
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Affiliation(s)
- Simon B Eickhoff
- Institute for Neuroscience and Biophysics-Medicine (INB 3), Research Centre Jülich GmbH, 52425 Jülich, Germany.
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1103
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Vartiainen J, Aggujaro S, Lehtonen M, Hultén A, Laine M, Salmelin R. Neural dynamics of reading morphologically complex words. Neuroimage 2009; 47:2064-72. [PMID: 19520173 DOI: 10.1016/j.neuroimage.2009.06.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 05/27/2009] [Accepted: 06/01/2009] [Indexed: 11/16/2022] Open
Abstract
Despite considerable research interest, it is still an open issue as to how morphologically complex words such as "car+s" are represented and processed in the brain. We studied the neural correlates of the processing of inflected nouns in the morphologically rich Finnish language. Previous behavioral studies in Finnish have yielded a robust inflectional processing cost, i.e., inflected words are harder to recognize than otherwise matched morphologically simple words. Theoretically this effect could stem either from decomposition of inflected words into a stem and a suffix at input level and/or from subsequent recombination at the semantic-syntactic level to arrive at an interpretation of the word. To shed light on this issue, we used magnetoencephalography to reveal the time course and localization of neural effects of morphological structure and frequency of written words. Ten subjects silently read high- and low-frequency Finnish words in inflected and monomorphemic form. Morphological complexity was accompanied by stronger and longer-lasting activation of the left superior temporal cortex from 200 ms onwards. Earlier effects of morphology were not found, supporting the view that the well-established behavioral processing cost for inflected words stems from the semantic-syntactic level rather than from early decomposition. Since the effect of morphology was detected throughout the range of word frequencies employed, the majority of inflected Finnish words appears to be represented in decomposed form and only very high-frequency inflected words may acquire full-form representations.
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Affiliation(s)
- Johanna Vartiainen
- Brain Research Unit, Low Temperature Laboratory, Helsinki University of Technology, Finland.
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1104
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Li P. Lexical Organization and Competition in First and Second Languages: Computational and Neural Mechanisms. Cogn Sci 2009; 33:629-64. [DOI: 10.1111/j.1551-6709.2009.01028.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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1105
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Miyata J, Hirao K, Namiki C, Fujiwara H, Shimizu M, Fukuyama H, Sawamoto N, Hayashi T, Murai T. Reduced white matter integrity correlated with cortico-subcortical gray matter deficits in schizophrenia. Schizophr Res 2009; 111:78-85. [PMID: 19361957 DOI: 10.1016/j.schres.2009.03.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Revised: 03/03/2009] [Accepted: 03/05/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND The pathology of schizophrenia is thought to involve multiple brain regions and the connections among them. Although a number of MRI studies have demonstrated gray matter reductions and abnormal white matter integrity in schizophrenia, to date no study has investigated their association in the whole brain. METHODS Twenty-seven schizophrenia patients and 33 healthy controls were recruited. Voxelwise group comparison of white matter fractional anisotropy (FA) was performed using tract-based spatial statistics (TBSS). Comparison of gray matter concentration (GMC) was performed using voxel-based morphometry (VBM). Voxelwise correlational analyses were performed for patients inside a significant GMC reduction mask created by VBM, using simple regression models with mean FA values of each significant TBSS cluster as explanatory variables. RESULTS TBSS revealed FA reduction in left prefrontal and occipital regions in the patients. Mean FA values of both areas revealed significant correlation with gray matter reduction in multiple cortical and subcortical areas, with overlapping but different patterns. CONCLUSIONS Voxelwise correlational analysis of white and gray matter pathology, as performed here, further elucidated the pathophysiology of schizophrenia, and provided a novel view of the "disconnection hypothesis" of schizophrenia.
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Affiliation(s)
- Jun Miyata
- Department of Neuropsychiatry, Graduate School of Medicine, Kyoto University, Shogoin-Kawaharacho 54, Kyoto 606-8507, Japan.
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1106
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Segregating the core computational faculty of human language from working memory. Proc Natl Acad Sci U S A 2009; 106:8362-7. [PMID: 19416819 DOI: 10.1073/pnas.0810928106] [Citation(s) in RCA: 224] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In contrast to simple structures in animal vocal behavior, hierarchical structures such as center-embedded sentences manifest the core computational faculty of human language. Previous artificial grammar learning studies found that the left pars opercularis (LPO) subserves the processing of hierarchical structures. However, it is not clear whether this area is activated by the structural complexity per se or by the increased memory load entailed in processing hierarchical structures. To dissociate the effect of structural complexity from the effect of memory cost, we conducted a functional magnetic resonance imaging study of German sentence processing with a 2-way factorial design tapping structural complexity (with/without hierarchical structure, i.e., center-embedding of clauses) and working memory load (long/short distance between syntactically dependent elements; i.e., subject nouns and their respective verbs). Functional imaging data revealed that the processes for structure and memory operate separately but co-operatively in the left inferior frontal gyrus; activities in the LPO increased as a function of structural complexity, whereas activities in the left inferior frontal sulcus (LIFS) were modulated by the distance over which the syntactic information had to be transferred. Diffusion tensor imaging showed that these 2 regions were interconnected through white matter fibers. Moreover, functional coupling between the 2 regions was found to increase during the processing of complex, hierarchically structured sentences. These results suggest a neuroanatomical segregation of syntax-related aspects represented in the LPO from memory-related aspects reflected in the LIFS, which are, however, highly interconnected functionally and anatomically.
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1107
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Husain FT, Patkin DJ, Thai-Van H, Braun AR, Horwitz B. Distinguishing the processing of gestures from signs in deaf individuals: an fMRI study. Brain Res 2009; 1276:140-50. [PMID: 19397900 DOI: 10.1016/j.brainres.2009.04.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 04/13/2009] [Accepted: 04/14/2009] [Indexed: 11/16/2022]
Abstract
Manual gestures occur on a continuum from co-speech gesticulations to conventionalized emblems to language signs. Our goal in the present study was to understand the neural bases of the processing of gestures along such a continuum. We studied four types of gestures, varying along linguistic and semantic dimensions: linguistic and meaningful American Sign Language (ASL), non-meaningful pseudo-ASL, meaningful emblematic, and nonlinguistic, non-meaningful made-up gestures. Pre-lingually deaf, native signers of ASL participated in the fMRI study and performed two tasks while viewing videos of the gestures: a visuo-spatial (identity) discrimination task and a category discrimination task. We found that the categorization task activated left ventral middle and inferior frontal gyrus, among other regions, to a greater extent compared to the visual discrimination task, supporting the idea of semantic-level processing of the gestures. The reverse contrast resulted in enhanced activity of bilateral intraparietal sulcus, supporting the idea of featural-level processing (analogous to phonological-level processing of speech sounds) of the gestures. Regardless of the task, we found that brain activation patterns for the nonlinguistic, non-meaningful gestures were the most different compared to the ASL gestures. The activation patterns for the emblems were most similar to those of the ASL gestures and those of the pseudo-ASL were most similar to the nonlinguistic, non-meaningful gestures. The fMRI results provide partial support for the conceptualization of different gestures as belonging to a continuum and the variance in the fMRI results was best explained by differences in the processing of gestures along the semantic dimension.
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Affiliation(s)
- Fatima T Husain
- Brain Imaging and Modeling Section, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA.
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1108
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Wu X, Lu J, Chen K, Long Z, Wang X, Shu H, Li K, Liu Y, Yao L. Multiple neural networks supporting a semantic task: An fMRI study using independent component analysis. Neuroimage 2009; 45:1347-58. [DOI: 10.1016/j.neuroimage.2008.12.050] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 11/06/2008] [Accepted: 12/17/2008] [Indexed: 10/21/2022] Open
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1109
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Soriano-Mas C, Pujol J, Ortiz H, Deus J, López-Sala A, Sans A. Age-related brain structural alterations in children with specific language impairment. Hum Brain Mapp 2009; 30:1626-36. [PMID: 18781595 PMCID: PMC6870989 DOI: 10.1002/hbm.20620] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2008] [Revised: 05/19/2008] [Accepted: 05/22/2008] [Indexed: 11/08/2022] Open
Abstract
Previous neuroimaging studies have suggested that children with specific language impairment (SLI) may show subtle anatomical alterations in specific brain regions. We aimed to characterize structural abnormalities in children with SLI using a voxel-wise analysis over the whole brain. Subjects covered a wide age range (5-17 years) in order to assess the dynamic nature of the disorder across childhood. Three-dimensional MRIs were collected from 36 children with SLI and from a comparable group of healthy controls. Global gray and white matter measurements were obtained for each subject, and voxel-based morphometry (VBM) was used to evaluate between-group differences in regional brain anatomy. Possible age-related changes were assessed in separate analyses of younger (below 11 years of age) and older children. SLI patients showed larger global gray and white matter volumes, particularly in the younger subgroup. Voxel-wise analyses of the whole sample showed two regions of increased gray matter volume in SLI: the right perisylvian region and the occipital petalia. Age-group analyses suggested a more extended pattern of volume increases in the younger subjects, which included entorhinal, temporopolar, caudate nucleus, motor-precentral and precuneus gray matter, and white matter of the frontal and temporal lobes. Our results suggest that in the SLI brain there are enduring anatomical alterations that exist across a wide age range, as well as a distributed pattern of abnormalities that appear to normalize with development. They also suggest that the neuroanatomical basis of SLI may be better characterized by considering the dynamic course of the disorder throughout childhood.
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Affiliation(s)
- Carles Soriano-Mas
- Institut d'Alta Tecnologia-PRBB, CRC Corporació Sanitària, Passeig Marítim 25-29, Hospital del Mar, Barcelona, Spain.
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1110
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Hultén A, Vihla M, Laine M, Salmelin R. Accessing newly learned names and meanings in the native language. Hum Brain Mapp 2009; 30:976-89. [PMID: 18412130 DOI: 10.1002/hbm.20561] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Ten healthy adults encountered pictures of unfamiliar archaic tools and successfully learned either their name, verbal definition of their usage, or both. Neural representation of the newly acquired information was probed with magnetoencephalography in an overt picture-naming task before and after learning, and in two categorization tasks after learning. Within 400 ms, activation proceeded from occipital through parietal to left temporal cortex, inferior frontal cortex (naming) and right temporal cortex (categorization). Comparison of naming of newly learned versus familiar pictures indicated that acquisition and maintenance of word forms are supported by the same neural network. Explicit access to newly learned phonology when such information was known strongly enhanced left temporal activation. By contrast, access to newly learned semantics had no comparable, direct neural effects. Both the behavioral learning pattern and neurophysiological results point to fundamentally different implementation of and access to phonological versus semantic features in processing pictured objects.
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Affiliation(s)
- Annika Hultén
- Brain Research Unit, Low Temperature Laboratory, Helsinki University of Technology, Espoo, Finland
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1111
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Abstract
Measuring event-related potentials (ERPs) has been fundamental to our understanding of how language is encoded in the brain. One particular ERP response, the N400 response, has been especially influential as an index of lexical and semantic processing. However, there remains a lack of consensus on the interpretation of this component. Resolving this issue has important consequences for neural models of language comprehension. Here we show that evidence bearing on where the N400 response is generated provides key insights into what it reflects. A neuroanatomical model of semantic processing is used as a guide to interpret the pattern of activated regions in functional MRI, magnetoencephalography and intracranial recordings that are associated with contextual semantic manipulations that lead to N400 effects.
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1112
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Léonard B, de Partz MP, Grandin C, Pillon A. Domain-specific reorganization of semantic processing after extensive damage to the left temporal lobe. Neuroimage 2009; 45:572-86. [DOI: 10.1016/j.neuroimage.2008.11.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 11/10/2008] [Accepted: 11/14/2008] [Indexed: 11/24/2022] Open
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1113
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Gestures orchestrate brain networks for language understanding. Curr Biol 2009; 19:661-7. [PMID: 19327997 DOI: 10.1016/j.cub.2009.02.051] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Revised: 02/13/2009] [Accepted: 02/13/2009] [Indexed: 11/21/2022]
Abstract
Although the linguistic structure of speech provides valuable communicative information, nonverbal behaviors can offer additional, often disambiguating cues. In particular, being able to see the face and hand movements of a speaker facilitates language comprehension [1]. But how does the brain derive meaningful information from these movements? Mouth movements provide information about phonological aspects of speech [2-3]. In contrast, cospeech gestures display semantic information relevant to the intended message [4-6]. We show that when language comprehension is accompanied by observable face movements, there is strong functional connectivity between areas of cortex involved in motor planning and production and posterior areas thought to mediate phonological aspects of speech perception. In contrast, language comprehension accompanied by cospeech gestures is associated with tuning of and strong functional connectivity between motor planning and production areas and anterior areas thought to mediate semantic aspects of language comprehension. These areas are not tuned to hand and arm movements that are not meaningful. Results suggest that when gestures accompany speech, the motor system works with language comprehension areas to determine the meaning of those gestures. Results also suggest that the cortical networks underlying language comprehension, rather than being fixed, are dynamically organized by the type of contextual information available to listeners during face-to-face communication.
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1114
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Is the left uncinate fasciculus essential for language? A cerebral stimulation study. J Neurol 2009; 256:382-9. [PMID: 19271103 DOI: 10.1007/s00415-009-0053-9] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2008] [Revised: 06/08/2008] [Accepted: 07/08/2008] [Indexed: 10/21/2022]
Abstract
Despite a better understanding of the anatomy of the uncinate fasciculus (UF), its function remains poorly known. Our aim was to study the exact role of UF in language, and the possible existence of parallel distributed language networks within the "ventral stream", underlaid by distinct subcortical tracts--namely the inferior occipito-temporal fasciculus (IOF) and UF.We report a series of 13 patients operated on awake for a glioma involving the left anterior temporal lobe or the orbitofrontal area. We used intraoperative electrostimulation, to perform accurate and reliable anatomofunctional correlations both at cortical and subcortical levels. Using postoperative MRI, we correlated these functional findings with the anatomical locations of the sites where language disturbances were elicited by stimulation.Intraoperative cortical stimulation found perilesional language sites in all cases. Subcortically, semantic paraphasia were induced in the 13 patients by stimulating the IOF, and phonological paraphasia were generated in 6 patients by stimulating the arcuate fasciculus. Interestingly, subcortical stimulation never elicited any language disturbances when performed at the level of the UF. Moreover, after a transient postoperative language deficit, all patients recovered, despite the removal of at least one part of the UF, as confirmed by control MRI.We suggest that UF is not systematically essential for language. It can be explained by the fact that the "semantic ventral stream" might be constituted by at least two parallel pathways, i. e. a direct pathway underlaid by the IOF, crucial for language semantics, and an indirect pathway subserved by UF, which can be functionally compensated. However, we have to underline the fact not all language functions can be probed during surgery, and that more sensitive tasks have now to be added.
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1115
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den Ouden DB, Fix S, Parrish TB, Thompson CK. Argument structure effects in action verb naming in static and dynamic conditions. JOURNAL OF NEUROLINGUISTICS 2009; 22:196-215. [PMID: 20160850 PMCID: PMC2659666 DOI: 10.1016/j.jneuroling.2008.10.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Argument structure, as in the participant roles entailed within the lexical representation of verbs, affects verb processing. Recent neuroimaging studies show that when verbs are heard or read, the posterior temporoparietal region shows increased activation for verbs with greater versus lesser argument structure complexity, usually bilaterally. In addition, patients with agrammatic aphasia show verb production deficits, graded based on argument structure complexity. In the present study, we used fMRI to examine the neural correlates of verb production in overt action naming conditions. In addition, we tested the differential effects of naming when verbs were presented dynamically in video segments versus statically in line drawings. Results showed increased neuronal activity associated with production of transitive as compared to intransitive verbs not only in posterior regions, but also in left inferior frontal cortex. We also found significantly greater activation for transitive versus intransitive action naming for videos compared to pictures in the right inferior and superior parietal cortices, areas associated with object manipulation. These findings indicate that verbs with greater argument structure density engender graded activation of both anterior and posterior portions of the language network and support verb naming deficit patterns reported in lesion studies. In addition, the similar findings derived under video and static picture naming conditions provide validity for using videos in neuroimaging studies, which are more naturalistic and perhaps ecologically valid than using static pictures to investigate action naming.
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Affiliation(s)
- Dirk-Bart den Ouden
- Aphasia and Neurolinguistics Laboratory, Roxelyn & Richard Pepper Department of Communication Sciences and Disorders, Northwestern University
| | - Steve Fix
- Aphasia and Neurolinguistics Laboratory, Roxelyn & Richard Pepper Department of Communication Sciences and Disorders, Northwestern University
| | - Todd B. Parrish
- Department of Radiology, Northwestern University Feinberg School of Medicine
- Cognitive Neurology and Alzheimer’s Disease Center, Northwestern University Feinberg School of Medicine
| | - Cynthia K. Thompson
- Aphasia and Neurolinguistics Laboratory, Roxelyn & Richard Pepper Department of Communication Sciences and Disorders, Northwestern University
- Department of Neurology, Northwestern University Feinberg School of Medicine
- Cognitive Neurology and Alzheimer’s Disease Center, Northwestern University Feinberg School of Medicine
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1116
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Tylén K, Wallentin M, Roepstorff A. Say it with flowers! An fMRI study of object mediated communication. BRAIN AND LANGUAGE 2009; 108:159-166. [PMID: 18771801 DOI: 10.1016/j.bandl.2008.07.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Revised: 07/07/2008] [Accepted: 07/24/2008] [Indexed: 05/26/2023]
Abstract
Human communicational interaction can be mediated by a host of expressive means from words in a natural language to gestures and material symbols. Given the proper contextual setting even an everyday object can gain a mediating function in a communicational situation. In this study we used event-related fMRI to study the brain activity caused by everyday material objects when they are perceived as signals. We found that comprehension of material signals activates bilaterally areas of the ventral stream and pars triangularis of the inferior frontal cortex, that is, areas traditionally associated with verbal language and semantics. In addition, we found that right-hemisphere inferior frontal cortex is recruited as a function of the increasing unconventionality of communicative objects. Together these findings support an interpretation of the traditional language areas as playing a more general role across modalities in relation to communicational mediation of social semantic meaning.
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Affiliation(s)
- Kristian Tylén
- Institute of Language and Communication, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
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1117
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Peters F, Majerus S, Collette F, Degueldre C, Del Fiore G, Laureys S, Moonen G, Salmon E. Neural substrates of phonological and lexicosemantic representations in Alzheimer's disease. Hum Brain Mapp 2009; 30:185-99. [PMID: 18095283 DOI: 10.1002/hbm.20493] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The language profile of patients suffering from Alzheimer's disease (AD) is characterized not only by lexicosemantic impairments but also by phonological deficits, as shown by an increasing number of neuropsychological studies. This study explored the functional neural correlates underlying phonological and lexicosemantic processing in AD. Using H(215)O PET functional brain imaging, a group of mild to moderate AD patients and a group of age-matched controls were asked to repeat four types of verbal stimuli: words, wordlike nonwords (WL+), non-wordlike nonwords (WL-) and simple vowels. The comparison between the different conditions allowed us to determine brain activation preferentially associated with lexicosemantic or phonological levels of language representations. When repeating words, AD patients showed decreased activity in the left temporo-parietal and inferior frontal regions relative to controls, consistent with distorted lexicosemantic representations. Brain activity was abnormally increased in the right superior temporal area during word repetition, a region more commonly associated with perceptual-phonological processing. During repetition of WL+ and WL- nonwords, AD patients showed decreased activity in the middle part of the superior temporal gyrus, presumably associated with sublexical phonological information; at the same time, AD patients showed larger activation than controls in the inferior temporal gyrus, typically associated with lexicosemantic levels of representation. Overall, the results suggest that AD patients use altered pathways to process phonological and lexicosemantic information, possibly related to a progressive loss of specialization of phonological and lexicosemantic neural networks.
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1118
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Bolger DJ, Hornickel J, Cone NE, Burman DD, Booth JR. Neural correlates of orthographic and phonological consistency effects in children. Hum Brain Mapp 2009; 29:1416-29. [PMID: 17957704 DOI: 10.1002/hbm.20476] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The objective of this study was to examine the neural correlates of phonological inconsistency (relationship of spelling to sound) and orthographic inconsistency (relationship of sound to spelling) in visual word processing using functional magnetic resonance imaging (fMRI). Children (9- to 15-year-old) performed a rhyming and spelling task in which two words were presented sequentially in the visual modality. Consistent with previous studies in adults, higher phonological inconsistency was associated with greater activation in several regions including left inferior frontal gyrus and medial frontal gyrus/anterior cingulate cortex. We additionally demonstrated an effect of orthographic inconsistency in these same areas, suggesting that these regions are involved in the integration of orthographic and phonological information and, with respect to the medial frontal/anterior cingulate, greater demands on executive function. Higher phonological and orthographic consistency was associated with greater activation in precuneus/posterior cingulate cortex, the putative steady state system active during resting, suggesting lower demands on cognitive resources for consistent items. Both consistency effects were larger for the rhyming compared with the spelling task suggesting greater demands of integrating spelling and sound in the former task. Finally, accuracy on the rhyming task was negatively correlated with the consistency effect in left fusiform gyrus. In particular, this region showed insensitivity to consistency in low performers, sensitivity to inconsistency (higher activity) in moderate performers, and sensitivity to inconsistency (high activation) and to consistency (deactivation). In general, these results show that the influence of spelling-sound (and sound-spelling) correspondences on processing in fusiform gyrus develops as a function of skill.
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Affiliation(s)
- Donald J Bolger
- Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois 60208, USA.
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1119
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Friederici AD. Pathways to language: fiber tracts in the human brain. Trends Cogn Sci 2009; 13:175-81. [PMID: 19223226 DOI: 10.1016/j.tics.2009.01.001] [Citation(s) in RCA: 336] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Revised: 01/16/2009] [Accepted: 01/16/2009] [Indexed: 10/21/2022]
Abstract
The human language function is not only based on the grey matter of circumscribed brain regions in the frontal and the temporal cortex but moreover on the white matter fiber tracts connecting these regions. Different pathways connecting frontal and temporal cortex have been identified. The dorsal pathway projecting from the posterior portion of Broca's area to the superior temporal region seems to be of particular importance for higher-order language functions. This pathway is particularly weak in non-human compared to human primates and in children compared to adults. It is therefore considered to be crucial for the evolution of human language, which is characterized by the ability to process syntactically complex sentences.
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Affiliation(s)
- Angela D Friederici
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig 04103, Germany.
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1120
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Rilling JK. Neuroscientific approaches and applications within anthropology. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2009; Suppl 47:2-32. [PMID: 19003891 DOI: 10.1002/ajpa.20947] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Many of the most distinctive attributes of our species are a product of our brains. To understand the function, development, variability, and evolution of the human brain, we must engage with the field of neuroscience. Neuroscientific methods can be used to investigate research topics that are of special interest to anthropologists, such as the neural bases of primate behavioral diversity, human brain evolution, and human brain development. Traditional neuroscience methods had to rely on investigation of postmortem brains, as well as invasive studies in living nonhuman primates. However, recent neuroimaging methods have made it possible to compare living human and nonhuman primate brains using noninvasive techniques such as structural and functional magnetic resonance imaging, positron emission tomography, and diffusion tensor imaging. These methods are providing an integrated picture of brain structure and function that was not previously available. With a combination of these traditional and modern neuroscience methods, we are beginning to explore and understand the neural bases of some of the most distinctive cognitive and behavioral attributes of the human species, including language, tool use, altruism, and mental self-projection, and we can now begin to propose plausible scenarios by which the neural substrates supporting these human specializations evolved from pre-existing neural circuitry serving related functions in common ancestors we shared with the living nonhuman primates. Consideration of the process of neurodevelopment suggests plausible mechanisms by which the highly encephalized human brain might have evolved. Neurodevelopmental studies also demonstrate that experience can shape both brain structure and function, providing a mechanism by which people of different cultures learn to act and think differently. Finally, not only can anthropologists benefit from neuroscience, neuroscience can benefit from the more sophisticated concept of evolution that anthropology offers, including an appreciation of evolutionary diversity as well as consideration of the process by which the human brain was formed during evolution.
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Affiliation(s)
- James K Rilling
- Department of Anthropology, Emory University, Atlanta, GA 30322, USA.
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1121
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Auer T, Pinter S, Kovacs N, Kalmar Z, Nagy F, Horvath RA, Koszo B, Kotek G, Perlaki G, Koves M, Kalman B, Komoly S, Schwarcz A, Woermann FG, Janszky J. Does obstetric brachial plexus injury influence speech dominance? Ann Neurol 2009; 65:57-66. [DOI: 10.1002/ana.21538] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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1122
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Abel S, Dressel K, Bitzer R, Kümmerer D, Mader I, Weiller C, Huber W. The separation of processing stages in a lexical interference fMRI-paradigm. Neuroimage 2009; 44:1113-24. [DOI: 10.1016/j.neuroimage.2008.10.018] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Revised: 10/05/2008] [Accepted: 10/13/2008] [Indexed: 11/16/2022] Open
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1123
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Hocking J, Price CJ. Dissociating verbal and nonverbal audiovisual object processing. BRAIN AND LANGUAGE 2009; 108:89-96. [PMID: 19101025 PMCID: PMC2693664 DOI: 10.1016/j.bandl.2008.10.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Revised: 09/30/2008] [Accepted: 10/09/2008] [Indexed: 05/27/2023]
Abstract
This fMRI study investigates how audiovisual integration differs for verbal stimuli that can be matched at a phonological level and nonverbal stimuli that can be matched at a semantic level. Subjects were presented simultaneously with one visual and one auditory stimulus and were instructed to decide whether these stimuli referred to the same object or not. Verbal stimuli were simultaneously presented spoken and written object names, and nonverbal stimuli were photographs of objects simultaneously presented with naturally occurring object sounds. Stimulus differences were controlled by including two further conditions that paired photographs of objects with spoken words and object sounds with written words. Verbal matching, relative to all other conditions, increased activation in a region of the left superior temporal sulcus that has previously been associated with phonological processing. Nonverbal matching, relative to all other conditions, increased activation in a right fusiform region that has previously been associated with structural and conceptual object processing. Thus, we demonstrate how brain activation for audiovisual integration depends on the verbal content of the stimuli, even when stimulus and task processing differences are controlled.
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Affiliation(s)
- Julia Hocking
- Wellcome Trust Centre for Neuroimaging, UCL, London, UK.
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1124
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Horn H, Federspiel A, Wirth M, Müller TJ, Wiest R, Wang JJ, Strik W. Structural and metabolic changes in language areas linked to formal thought disorder. Br J Psychiatry 2009; 194:130-8. [PMID: 19182174 DOI: 10.1192/bjp.bp.107.045633] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND The role of the language network in the pathophysiology of formal thought disorder has yet to be elucidated. AIMS To investigate whether specific grey-matter deficits in schizophrenic formal thought disorder correlate with resting perfusion in the left-sided language network. METHOD We investigated 13 right-handed patients with schizophrenia and formal thought disorder of varying severity and 13 matched healthy controls, using voxel-based morphometry and magnetic resonance imaging perfusion measurement (arterial spin labelling). RESULTS We found positive correlations between perfusion and the severity of formal thought disorder in the left frontal and left temporoparietal language areas. We also observed bilateral deficits in grey-matter volume, positively correlated with the severity of thought disorder in temporoparietal areas and other brain regions. The results of the voxel-based morphometry and the arterial spin labelling measurements overlapped in the left posterior superior temporal gyrus and left angular gyrus. CONCLUSIONS Specific grey-matter deficits may be a risk factor for state-related dysfunctions of the left-sided language system, leading to local hyperperfusion and formal thought disorder.
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Affiliation(s)
- Helge Horn
- University Hospital of Psychiatry, Bolligenstrasse 111, CH-3000, Bern 60, Switzerland.
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1125
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Schatz J, Puffer ES, Sanchez C, Stancil M, Roberts CW. Language Processing Deficits in Sickle Cell Disease in Young School-Age Children. Dev Neuropsychol 2009; 34:122-36. [DOI: 10.1080/87565640802499191] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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1126
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Abstract
An important and unresolved question is how the human brain processes speech for meaning after initial analyses in early auditory cortical regions. A variety of left-hemispheric areas have been identified that clearly support semantic processing, although a systematic analysis of directed interactions among these areas is lacking. We applied dynamic causal modeling of functional magnetic resonance imaging responses and Bayesian model selection to investigate, for the first time, experimentally induced changes in coupling among three key multimodal regions that were activated by intelligible speech: the posterior and anterior superior temporal sulcus (pSTS and aSTS, respectively) and pars orbitalis (POrb) of the inferior frontal gyrus. We tested 216 different dynamic causal models and found that the best model was a "forward" system that was driven by auditory inputs into the pSTS, with forward connections from the pSTS to both the aSTS and the POrb that increased considerably in strength (by 76 and 150%, respectively) when subjects listened to intelligible speech. Task-related, directional effects can now be incorporated into models of speech comprehension.
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1127
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The problem of aphasia in the assessment of consciousness in brain-damaged patients. PROGRESS IN BRAIN RESEARCH 2009; 177:49-61. [PMID: 19818894 DOI: 10.1016/s0079-6123(09)17705-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The assessment of the level and content of consciousness in brain-damaged patients relies to a large extent on behavioral assessment techniques. The limited behavioral repertoire displayed by vegetative and minimally conscious states requires the use of highly sensitive and reliable behavioral assessment methods, allowing the detection of subtle changes in behavior and associated level of consciousness. This situation is further complicated when patients with such disorders of consciousness have underlying deficits in the domain of communication functions, such as aphasia. The present paper examines the consequences of receptive and/or productive aphasia on the already limited behavioral repertoire presented in these patients and discusses a number of behavioral and neuroimaging assessment procedures designed to: (1) detect the presence of aphasia in patients with disorders of consciousness, and (2) reliably assess the level of consciousness of brain-damaged patients while taking into account the existence of receptive and/or expressive language deficits. The combined use of behavioral and neuroimaging assessment techniques appears to be particularly promising for disentangling impaired consciousness and aphasia.
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1128
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[Functional magnetic resonance imaging in brain tumour neurosurgical resection risk assessment]. ACTA CHIRURGICA IUGOSLAVICA 2009; 56:31-6. [PMID: 20419993 DOI: 10.2298/aci0904031s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
UNLABELLED To establish the possibilities of functional magnetic resonance (fMRI) in the assesment of preservation of the motor and speech brain functions in the primary brain tumour patients planed for neurosurgery. METHODS AND MATERIAL fMRI of motor and/or speech areas was performed on 3T MRI unit in 17 patients with primary brain tumours and dominant focal epileptic symptomatology. RESULTS None of the patients demonstrated motor neurologic deficit before the operation, while in one patient a moderate speech disorder was noted. Operative treatment has been performed in 11/17 patients, and in 6/11 patients total tumour resection has been performed. Motor deficit has not been noted in any of the patients. Transitory speech deficit was noted in 3/11 patients, while 1/11 patients demonstrated a permanent but mild speech deficit. CONCLUSION fMRI may be of significant help in the assessment of potential postoperative neurological deficit risks, enabling the optimization of neurosurgical resection procedure in the brain tumour patients.
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1129
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Perrone M, Cousin É, Baciu A, Baciu M. Modulation de la spécialisation hémisphérique du langage par le degré de transparence graphophonémique et le genre des participants. ACTA ACUST UNITED AC 2009. [DOI: 10.3917/rne.014.0288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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1130
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The neurocognitive basis of reading single words as seen through early latency ERPs: A model of converging pathways. Biol Psychol 2009; 80:10-22. [PMID: 18538915 DOI: 10.1016/j.biopsycho.2008.04.013] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Revised: 04/28/2008] [Accepted: 04/28/2008] [Indexed: 11/23/2022]
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1131
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Korzeniewska A, Crainiceanu CM, Kuś R, Franaszczuk PJ, Crone NE. Dynamics of event-related causality in brain electrical activity. Hum Brain Mapp 2008; 29:1170-92. [PMID: 17712784 PMCID: PMC6870676 DOI: 10.1002/hbm.20458] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A new method (Event-Related Causality, ERC) is proposed for the investigation of functional interactions between brain regions during cognitive processing. ERC estimates the direction, intensity, spectral content, and temporal course of brain activity propagation within a cortical network. ERC is based upon the short-time directed transfer function (SDTF), which is measured in short EEG epochs during multiple trials of a cognitive task, as well as the direct directed transfer function (dDTF), which distinguishes direct interactions between brain regions from indirect interactions via brain regions. ERC uses new statistical methods for comparing estimates of causal interactions during prestimulus "baseline" epochs and during poststimulus "activated" epochs in order to estimate event-related increases and decreases in the functional interactions between cortical network components during cognitive tasks. The utility of the ERC approach is demonstrated through its application to human electrocorticographic recordings (ECoG) of a simple language task. ERC analyses of these ECoG recordings reveal frequency-dependent interactions, particularly in high gamma (>60 Hz) frequencies, between brain regions known to participate in the recorded language task, and the temporal evolution of these interactions is consistent with the putative processing stages of this task. The method may be a useful tool for investigating the dynamics of causal interactions between various brain regions during cognitive task performance.
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Affiliation(s)
- Anna Korzeniewska
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Meyer 2‐147, Baltimore, Maryland
| | - Ciprian M. Crainiceanu
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., E3636, Baltimore, Maryland
| | - Rafał Kuś
- Department of Biomedical Physics, Institute of Experimental Physics, Warsaw University, ul. Hoza 69, 00‐681 Warsaw, Poland
| | - Piotr J. Franaszczuk
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Meyer 2‐147, Baltimore, Maryland
| | - Nathan E. Crone
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Meyer 2‐147, Baltimore, Maryland
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1132
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Dien J, O'Hare AJ. Evidence for automatic sentence priming in the fusiform semantic area: Convergent ERP and fMRI findings. Brain Res 2008; 1243:134-45. [DOI: 10.1016/j.brainres.2008.09.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 08/30/2008] [Accepted: 09/12/2008] [Indexed: 11/28/2022]
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1133
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Abstract
Recent studies have suggested that some variants of bipolar disorder (BD) may be due to hyperconnectivity between orbitofrontal (OFC) and temporal pole (TP) structures in the dominant hemisphere. Some initial MRI studies noticed that there were corpus callosum abnormalities within specific regional areas and it was hypothesized that developmentally this could result in functional or effective connectivity changes within the orbitofrontal-basal ganglia-thalamocortical circuits. Recent diffusion tensor imaging (DTI) white matter fiber tractography studies may well be superior to region of interest (ROI) DTI in understanding BD. A "ventral semantic stream" has been discovered connecting the TP and OFC through the uncinate and inferior longitudinal fasciculi and the elusive TP is known to be involved in theory of mind and complex narrative understanding tasks. The OFC is involved in abstract valuation in goal and sub-goal structures and the TP may be critical in binding semantic memory with person-emotion linkages associated with narrative. BD patients have relative attenuation of performance on visuoconstructional praxis consistent with an atypical localization of cognitive functions. Multiple lines of evidence suggest that some BD alleles are being selected for which could explain the enhanced creativity in higher-ability probands. Associations between ROI's that are not normally connected could explain the higher incidence of artistic aptitude, writing ability, and scientific achievements among some mood disorder subjects.
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Affiliation(s)
- Simon M McCrea
- Departments of Neurology and Neuroophthalmology, University of British Columbia, 2550 Willow Street, Vancouver, British Columbia, Canada V5Z 3N9.
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1134
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Duffau H, Leroy M, Gatignol P. Cortico-subcortical organization of language networks in the right hemisphere: An electrostimulation study in left-handers. Neuropsychologia 2008; 46:3197-209. [DOI: 10.1016/j.neuropsychologia.2008.07.017] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2008] [Revised: 07/22/2008] [Accepted: 07/22/2008] [Indexed: 11/30/2022]
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1135
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Bolger DJ, Minas J, Burman DD, Booth JR. Differential effects of orthographic and phonological consistency in cortex for children with and without reading impairment. Neuropsychologia 2008; 46:3210-24. [PMID: 18725239 PMCID: PMC2658621 DOI: 10.1016/j.neuropsychologia.2008.07.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Revised: 07/08/2008] [Accepted: 07/23/2008] [Indexed: 10/21/2022]
Abstract
One of the central challenges in mastering English is becoming sensitive to consistency from spelling to sound (i.e. phonological consistency) and from sound to spelling (i.e. orthographic consistency). Using functional magnetic resonance imaging (fMRI), we examined the neural correlates of consistency in 9-15-year-old Normal and Impaired Readers during a rhyming task in the visual modality. In line with our previous study [Bolger, D.J., Hornickel, J., Cone, N. E., Burman, D. D., & Booth,J. R. (in press). Neural correlates of orthographic and phonological consistency effects in children. Human Brain Mapping], for Normal Readers, lower phonological and orthographic consistency were associated with greater activation in several regions including bilateral inferior/middle frontal gyri, bilateral anterior cingulate cortex as well as left fusiform gyrus. Impaired Readers activated only bilateral anterior cingulate cortex in response to decreasing consistency. Group comparisons revealed that, relative to Impaired Readers, Normal Readers exhibited a larger response in this network for lower phonological consistency whereas orthographic consistency differences were limited. Lastly, brain-behavior correlations revealed a significant relationship between skill (i.e. Phonological Awareness and non-word decoding) and cortical consistency effects for Impaired Readers in left inferior/middle frontal gyri and left fusiform gyrus. Impaired Readers with higher skill showed greater activation for higher consistency. This relationship was reliably different from that of Normal Readers in which higher skill was associated with greater activation for lower consistency. According to single-route or connectionist models, these results suggest that Impaired Readers with higher skill devote neural resources to representing the mapping between orthography and phonology for higher consistency words, and therefore do not robustly activate this network for lower consistency words.
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Affiliation(s)
- Donald J Bolger
- Department of Communication Sciences and Disorders, Northwestern University, 2240 Campus Drive, Evanston, IL 60208, USA
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1136
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Wager TD, Lindquist MA, Nichols TE, Kober H, Van Snellenberg JX. Evaluating the consistency and specificity of neuroimaging data using meta-analysis. Neuroimage 2008; 45:S210-21. [PMID: 19063980 DOI: 10.1016/j.neuroimage.2008.10.061] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 09/22/2008] [Accepted: 10/15/2008] [Indexed: 11/19/2022] Open
Abstract
Making sense of a neuroimaging literature that is growing in scope and complexity will require increasingly sophisticated tools for synthesizing findings across studies. Meta-analysis of neuroimaging studies fills a unique niche in this process: It can be used to evaluate the consistency of findings across different laboratories and task variants, and it can be used to evaluate the specificity of findings in brain regions or networks to particular task types. This review discusses examples, implementation, and considerations when choosing meta-analytic techniques. It focuses on the multilevel kernel density analysis (MKDA) framework, which has been used in recent studies to evaluate consistency and specificity of regional activation, identify distributed functional networks from patterns of co-activation, and test hypotheses about functional cortical-subcortical pathways in healthy individuals and patients with mental disorders. Several tests of consistency and specificity are described.
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Affiliation(s)
- Tor D Wager
- Department of Psychology, Columbia University, 1190 Amsterdam Ave, New York, NY 10027, USA.
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1137
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Abstract
Built on an analogy between the visual and auditory systems, the following dual stream model for language processing was suggested recently: a dorsal stream is involved in mapping sound to articulation, and a ventral stream in mapping sound to meaning. The goal of the study presented here was to test the neuroanatomical basis of this model. Combining functional magnetic resonance imaging (fMRI) with a novel diffusion tensor imaging (DTI)-based tractography method we were able to identify the most probable anatomical pathways connecting brain regions activated during two prototypical language tasks. Sublexical repetition of speech is subserved by a dorsal pathway, connecting the superior temporal lobe and premotor cortices in the frontal lobe via the arcuate and superior longitudinal fascicle. In contrast, higher-level language comprehension is mediated by a ventral pathway connecting the middle temporal lobe and the ventrolateral prefrontal cortex via the extreme capsule. Thus, according to our findings, the function of the dorsal route, traditionally considered to be the major language pathway, is mainly restricted to sensory-motor mapping of sound to articulation, whereas linguistic processing of sound to meaning requires temporofrontal interaction transmitted via the ventral route.
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1138
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Snijders TM, Vosse T, Kempen G, Van Berkum JJA, Petersson KM, Hagoort P. Retrieval and unification of syntactic structure in sentence comprehension: an FMRI study using word-category ambiguity. ACTA ACUST UNITED AC 2008; 19:1493-503. [PMID: 19001084 DOI: 10.1093/cercor/bhn187] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Sentence comprehension requires the retrieval of single word information from long-term memory, and the integration of this information into multiword representations. The current functional magnetic resonance imaging study explored the hypothesis that the left posterior temporal gyrus supports the retrieval of lexical-syntactic information, whereas left inferior frontal gyrus (LIFG) contributes to syntactic unification. Twenty-eight subjects read sentences and word sequences containing word-category (noun-verb) ambiguous words at critical positions. Regions contributing to the syntactic unification process should show enhanced activation for sentences compared to words, and only within sentences display a larger signal for ambiguous than unambiguous conditions. The posterior LIFG showed exactly this predicted pattern, confirming our hypothesis that LIFG contributes to syntactic unification. The left posterior middle temporal gyrus was activated more for ambiguous than unambiguous conditions (main effect over both sentences and word sequences), as predicted for regions subserving the retrieval of lexical-syntactic information from memory. We conclude that understanding language involves the dynamic interplay between left inferior frontal and left posterior temporal regions.
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Affiliation(s)
- Tineke M Snijders
- F.C. Donders Centre for Cognitive Neuroimaging, Nijmegen, the Netherlands.
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1139
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Thought disorder and frontotemporal volumes in pediatric epilepsy. Epilepsy Behav 2008; 13:593-9. [PMID: 18652915 PMCID: PMC2746463 DOI: 10.1016/j.yebeh.2008.06.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 06/19/2008] [Accepted: 06/19/2008] [Indexed: 11/20/2022]
Abstract
The aim of this study was to determine if volumes of frontotemporal regions associated with language were related to thought disorder in 42 children, aged 5-16 years, with cryptogenic epilepsy, all of whom had complex partial seizures (CPS). The children with CPS and 41 age- and gender-matched healthy children underwent brain MRI scans at 1.5 T. Tissue was segmented, and total brain, frontal lobe, and temporal lobe volumes were computed. Thought disorder measures, IQ, and seizure information were collected for each patient. The subjects with CPS had more thought disorder, smaller total gray matter and orbital frontal gray matter volumes, as well as larger temporal lobe white matter volumes than the control group. In the CPS group, thought disorder was significantly related to smaller orbital frontal and inferior frontal gray matter volumes, increased Heschl's gyrus gray matter volumes, and smaller superior temporal gyrus white matter volumes. However, significantly larger orbital frontal gyrus, superior temporal gyrus, and temporal lobe gray matter volumes and decreased Heschl's gyrus white matter volumes were associated with thought disorder in the control group. These findings suggest that thought disorder might represent a developmental disability involving frontotemporal regions associated with language in pediatric CPS.
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1140
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Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by language and communication impairments, social impairments, and repetitive behaviors or restricted interests. Previous studies of semantic functions have found differences in semantic processing and differences in the activation of the language network in adults with ASD compared to controls. The goal of this study is to examine semantic functions in adolescents with ASD compared to typically developing adolescents. We utilized fMRI with a reading version of a response-naming task to investigate activation in 12 right-handed adolescent boys with ASD and 12 typically developing boys. Both groups performed the task at ceiling levels. Boys with ASD had significantly stronger activation than controls in Broca's area, which was less left lateralized in ASD individuals. Controls had a significant correlation between frontal and temporal language area activation in the left hemisphere, whereas ASD adolescents did not. Direct group comparisons revealed additional regions activated in the ASD group relative to the control group. These results suggest differences in semantic organization, approaches to the semantic task, or efficiency in semantic processing in ASD adolescents relative to typically developing adolescents.
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1141
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Zhao J, Shu H, Zhang L, Wang X, Gong Q, Li P. Cortical competition during language discrimination. Neuroimage 2008; 43:624-33. [DOI: 10.1016/j.neuroimage.2008.07.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 06/28/2008] [Accepted: 07/07/2008] [Indexed: 11/30/2022] Open
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1142
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Fractionated resection on low grade gliomas involving Brocaʼs area and insights to brain plasticity. Chin Med J (Engl) 2008. [DOI: 10.1097/00029330-200810020-00015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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1143
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Willems RM, Ozyürek A, Hagoort P. Seeing and hearing meaning: ERP and fMRI evidence of word versus picture integration into a sentence context. J Cogn Neurosci 2008; 20:1235-49. [PMID: 18284352 DOI: 10.1162/jocn.2008.20085] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Understanding language always occurs within a situational context and, therefore, often implies combining streams of information from different domains and modalities. One such combination is that of spoken language and visual information, which are perceived together in a variety of ways during everyday communication. Here we investigate whether and how words and pictures differ in terms of their neural correlates when they are integrated into a previously built-up sentence context. This is assessed in two experiments looking at the time course (measuring event-related potentials, ERPs) and the locus (using functional magnetic resonance imaging, fMRI) of this integration process. We manipulated the ease of semantic integration of word and/or picture to a previous sentence context to increase the semantic load of processing. In the ERP study, an increased semantic load led to an N400 effect which was similar for pictures and words in terms of latency and amplitude. In the fMRI study, we found overlapping activations to both picture and word integration in the left inferior frontal cortex. Specific activations for the integration of a word were observed in the left superior temporal cortex. We conclude that despite obvious differences in representational format, semantic information coming from pictures and words is integrated into a sentence context in similar ways in the brain. This study adds to the growing insight that the language system incorporates (semantic) information coming from linguistic and extralinguistic domains with the same neural time course and by recruitment of overlapping brain areas.
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Affiliation(s)
- Roel M Willems
- FC Donders Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, The Netherlands.
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1144
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Seghier ML, Lee HL, Schofield T, Ellis CL, Price CJ. Inter-subject variability in the use of two different neuronal networks for reading aloud familiar words. Neuroimage 2008; 42:1226-36. [PMID: 18639469 PMCID: PMC2724104 DOI: 10.1016/j.neuroimage.2008.05.029] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 05/14/2008] [Accepted: 05/15/2008] [Indexed: 11/16/2022] Open
Abstract
Cognitive models of reading predict that high frequency regular words can be read in more than one way. We investigated this hypothesis using functional MRI and covariance analysis in 43 healthy skilled readers. Our results dissociated two sets of regions that were differentially engaged across subjects who were reading the same familiar words. Some subjects showed more activation in left inferior frontal and anterior occipito-temporal regions while other subjects showed more activation in right inferior parietal and left posterior occipito-temporal regions. To explore the behavioural correlates of these systems, we measured the difference between reading speed for irregularly spelled words relative to pseudowords outside the scanner in fifteen of our subjects and correlated this measure with fMRI activation for reading familiar words. The faster the lexical reading the greater the activation in left posterior occipito-temporal and right inferior parietal regions. Conversely, the slower the lexical reading the greater the activation in left anterior occipito-temporal and left ventral inferior frontal regions. Thus, the double dissociation in irregular and pseudoword reading behaviour predicted the double dissociation in neuronal activation for reading familiar words. We discuss the implications of these results which may be important for understanding how reading is learnt in childhood or re-learnt following brain damage in adulthood.
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Affiliation(s)
- M L Seghier
- Wellcome Trust Centre for Neuroimaging, Institute of Neurology, UCL, London, UK.
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1145
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Dien J, Franklin MS, Michelson CA, Lemen LC, Adams CL, Kiehl KA. fMRI characterization of the language formulation area. Brain Res 2008; 1229:179-92. [DOI: 10.1016/j.brainres.2008.06.107] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2007] [Revised: 10/26/2007] [Accepted: 06/18/2008] [Indexed: 11/30/2022]
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1146
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A common anterior insula representation of disgust observation, experience and imagination shows divergent functional connectivity pathways. PLoS One 2008; 3:e2939. [PMID: 18698355 PMCID: PMC2491556 DOI: 10.1371/journal.pone.0002939] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Accepted: 07/10/2008] [Indexed: 12/30/2022] Open
Abstract
Similar brain regions are involved when we imagine, observe and execute an action. Is the same true for emotions? Here, the same subjects were scanned while they (a) experience, (b) view someone else experiencing and (c) imagine experiencing gustatory emotions (through script-driven imagery). Capitalizing on the fact that disgust is repeatedly inducible within the scanner environment, we scanned the same participants while they (a) view actors taste the content of a cup and look disgusted (b) tasted unpleasant bitter liquids to induce disgust, and (c) read and imagine scenarios involving disgust and their neutral counterparts. To reduce habituation, we inter-mixed trials of positive emotions in all three scanning experiments. We found voxels in the anterior Insula and adjacent frontal operculum to be involved in all three modalities of disgust, suggesting that simulation in the context of social perception and mental imagery of disgust share a common neural substrates. Using effective connectivity, this shared region however was found to be embedded in distinct functional circuits during the three modalities, suggesting why observing, imagining and experiencing an emotion feels so different.
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1147
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Wirth M, Horn H, Koenig T, Razafimandimby A, Stein M, Mueller T, Federspiel A, Meier B, Dierks T, Strik W. The early context effect reflects activity in the temporo-prefrontal semantic system: Evidence from electrical neuroimaging of abstract and concrete word reading. Neuroimage 2008; 42:423-36. [DOI: 10.1016/j.neuroimage.2008.03.045] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 03/17/2008] [Accepted: 03/19/2008] [Indexed: 10/22/2022] Open
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1148
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Eckert MA, Lombardino LJ, Walczak AR, Bonihla L, Leonard CM, Binder JR. Manual and automated measures of superior temporal gyrus asymmetry: concordant structural predictors of verbal ability in children. Neuroimage 2008; 41:813-22. [PMID: 18440244 PMCID: PMC4201835 DOI: 10.1016/j.neuroimage.2008.03.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 02/28/2008] [Accepted: 03/03/2008] [Indexed: 11/19/2022] Open
Abstract
The planum temporale is a region on the posterior surface of the temporal lobe that exhibits robust leftward structural asymmetry, which has been linked to verbal ability in children and adults. Traditionally, structural asymmetry has been quantified with manual assessment of high resolution MRI scans. Such measures require subjective and frequently unreliable determination of highly variable anatomical boundaries. Methodological developments in automated image processing (voxel-based morphometry - VBM) offer the opportunity to obtain objective and reliable measures of structural variation. This study examined the extent to which a VBM measure of gray matter asymmetry in the posterior superior temporal gyrus (pSTG) characterized the same individual variation as a manual measure of planum temporale asymmetry in 99 healthy adults and 39 typically developing children. Planum temporale asymmetry was significantly correlated with pSTG gray matter asymmetry in the samples of adults and children. As a measure of validity we examined the extent to which the VBM measure of pSTG gray matter asymmetry predicted measures of verbal ability that were associated with the manual measure of planum temporale asymmetry in the same children. The two asymmetry measures predicted the same variance in verbal ability. The automated measure of pSTG gray matter asymmetry predicted additional significant variance in verbal ability, however. In addition, a posterior STS region was also identified that significantly predicted verbal ability. These results demonstrate significant advantages of an automated voxel-based measure over a manual measure of planum temporale asymmetry.
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Affiliation(s)
- Mark A Eckert
- Medical University of South Carolina, Department of Otolaryngology, Head and Neck Surgery, SC 29425, USA.
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1149
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Rapcsak SZ, Beeson PM, Henry ML, Leyden A, Kim E, Rising K, Andersen S, Cho H. Phonological dyslexia and dysgraphia: cognitive mechanisms and neural substrates. Cortex 2008; 45:575-91. [PMID: 18625494 DOI: 10.1016/j.cortex.2008.04.006] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Revised: 04/08/2008] [Accepted: 04/09/2008] [Indexed: 11/30/2022]
Abstract
To examine the validity of different theoretical assumptions about the neuropsychological mechanisms and lesion correlates of phonological dyslexia and dysgraphia, we studied written and spoken language performance in a large cohort of patients with focal damage to perisylvian cortical regions implicated in phonological processing. Despite considerable variation in accuracy for both words and non-words, the majority of participants demonstrated the increased lexicality effects in reading and spelling that are considered the hallmark features of phonological dyslexia and dysgraphia. Increased lexicality effects were also documented in spoken language tasks such as oral repetition, and patients performed poorly on a battery of phonological tests that did not involve an orthographic component. Furthermore, a composite measure of general phonological ability was strongly predictive of both reading and spelling accuracy, and we obtained evidence that the continuum of severity that characterized the written language disorder of our patients was attributable to an underlying continuum of phonological impairment. Although patients demonstrated qualitatively similar deficits across measures of written and spoken language processing, there were quantitative differences in levels of performance reflecting task difficulty effects. Spelling was more severely affected than reading by the reduction in phonological capacity and this differential vulnerability accounted for occasional disparities between patterns of impairment on the two written language tasks. Our findings suggest that phonological dyslexia and dysgraphia in patients with perisylvian lesions are manifestations of a central or modality-independent phonological deficit rather than the result of damage to cognitive components dedicated to reading or spelling. Our results also provide empirical support for shared-components models of written language processing, according to which the same central cognitive systems support both reading and spelling. Lesion-deficit correlations indicated that phonological dyslexia and dysgraphia may be produced by damage to a variety of perisylvian cortical regions, consistent with distributed network models of phonological processing.
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1150
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Hoekert M, Bais L, Kahn RS, Aleman A. Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional prosody perception. PLoS One 2008; 3:e2244. [PMID: 18493307 PMCID: PMC2373925 DOI: 10.1371/journal.pone.0002244] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Accepted: 04/10/2008] [Indexed: 11/19/2022] Open
Abstract
In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody) conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS) to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms). Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction), revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become more apparent half-way through the sentence.
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Affiliation(s)
- Marjolijn Hoekert
- BCN Neuroimaging Center, University of Groningen, Groningen, The Netherlands.
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