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Shining new light on the brain's "bilingual signature": A functional Near Infrared Spectroscopy investigation of semantic processing

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NEUROimage 2008年第3期39卷 1457-1471页

作者： Kovelman, Loulia Shalinsky, Mark H. Berens, Melody S. Petitto, Laura-Ann Univ Toronto Scarborough Dept Psychol Toronto ON MIC 1A4 Canada MIT Cambridge MA 02139 USA Harvard Univ Sch Med Massachusetts Gen Hosp Anthinoula A Martinos Ctr Biomed Imaging Cambridge MA 02138 USA

Decades of research have shown that, from an early age, proficient bilinguals can speak each of their two languages separately (similar to monolinguals) or rapidly switch between them (dissimilar to monolinguals). Thus we ask, do monolingual and bilingual brains process language similarly or dissimilarly, and is this affected by the language context? Using an innovative brain imaging technology, functional Near Infrared Spectroscopy (fNIRS), we investigated how adult bilinguals process semantic information, both in speech and in print, in a monolingual language context (one language at a time) or in a bilingual language context (two languages in rapid alternation). While undergoing fNIRS recording, ten early exposed, highly proficient Spanish-English bilinguals completed a Semantic Judgment task in monolingual and bilingual contexts and were compared to ten English monolingual controls. Two hypotheses were tested: the Signature Hypothesis predicts that early, highly proficient bilinguals will recruit neural tissue to process language differently from monolinguals across all language contexts. The Switching Hypothesis predicts that bilinguals will recruit neural tissue to process language similarly to monolinguals, when using one language at a time. Supporting the Signature Hypothesis, in the monolingual context, bilinguals and monolinguals showed differences in both hemispheres in the recruitment of DLPFC (BA 46/9) and IFC (BA 47/11), but similar recruitment of Broca's area (BA 44/45). In particular, in the monolingual context, bilinguals showed greater signal intensity in channels maximally overlaying DLPFC and IFC regions as compared to monolinguals. In the bilingual context, bilinguals demonstrated a more robust recruitment of right DLPFC and right IFC. These findings reveal how extensive early bilingual exposure modifies language organization in the brain-thus imparting a possible "bilingual signature." They further shed fascinating new light on how the bilingua

关键词： Acoustic Stimulation Adult Brain/physiology Electroencephalography Female Humans image processing, computer-assisted Magnetic Resonance Imaging Male Multilingualism Photic Stimulation Prefrontal Cortex/physiology Psycholinguistics Psychomotor Performance/physiology Reading Spectroscopy, Near-Infrared Speech Perception/physiology

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Rates of brain atrophy over time in autopsy-proven frontotemporal dementia and Alzheimer disease

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NEUROimage 2008年第3期39卷 1034-1040页

作者： Whitwell, Jennifer L. Jack, Clifford R., Jr. Pankratz, V. Shane Parisi, Joseph E. Knopman, David S. Boeve, Bradley F. Petersen, Ronald C. Dickson, Dennis W. Josephs, Keith A. Mayo Clin Dept Neurol Rochester MN 55905 USA Mayo Clin Dept Radiol Rochester MN USA Mayo Clin Dept Hlth Sci Res Rochester MN USA Mayo Clin Dept Lab Med & Pathol Rochester MN USA Mayo Clin Dept Neurosci Jacksonville FL 32224 USA

Rates of brain loss have been shown to accelerate over time in early Alzheimer disease (AD);however the trajectory of change in frontotemporal lobar degeneration with ubiquitin immunoreactive-changes (FTLD-U) is unknown. This study compared the progression of atrophy over multiple MRI in subjects with autopsy-confirmed AD and FTLD-U. Nine subjects with autopsy-confirmed FTLD-U and nine with autopsy-confirmed AD were identified that had three or more serial MRI. The boundary-shift integral was used to calculate change over time in whole-brain and ventricular volume. A hierarchical regression model Was used to estimate the slope of volume change in AD and FTLD-U over time and to estimate differences in the slopes across the subject groups. Whole-brain volume loss did not deviate from a linear rate over time in both AD and FTLD-U subjects, although this may be due to limited sample size. The FTLD-U subjects had a faster rate (23 ml/year) than the AD subjects (10 ml/year). The rate of ventricular expansion accelerated over time. At the point when each subject had a Clinical Dementia Rating Sum-of-Boxes score of 6, the annual rate was 7 ml/year in FTLD-U and 5 ml/year in AD. These rates of change increased by an estimated 1.66 ml/year in FTLD-U and 0.44 ml/year in AD, although these estimates were not significantly different between the two groups. The trajectories of brain and ventricular changes were similar in AD and FTLD-U suggesting that it is independent of pathology, although subjects with FTLD-U show a more rapidly progressive decline. (c) 2007 Elsevier Inc. All rights reserved.

关键词： Aged Aged, 80 and over Alzheimer Disease/pathology Atrophy Autopsy Autopsy Brain/pathology Cerebral Ventricles/pathology Dementia/pathology Disease Progression Female Humans image processing, computer-assisted Longitudinal Studies Magnetic Resonance Imaging Male Middle Aged Regression Analysis

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A selective representation of the meaning of actions in the auditory mirror system

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NEUROimage 2008年第3期40卷 1274-1286页

作者： Galati, Gaspare Committeri, Giorgia Spitoni, Grazia Aprile, Teresa Di Russo, Francesco Pitzalis, Sabrina Pizzamiglio, Luigi Univ G dAnnunzio Dept Clin Sci & Bioimaging Neuropsychol Lab I-66013 Chieti Italy Univ G Annunzio Fdn I-66013 Chieti Italy IRCCS Santa Lucia Fdn Neuroimaging Lab I-00179 Rome Italy Sapienza Univ Dept Psychol I-00185 Rome Italy IRCCS Fdn Santa Lucia Neuropsychol Lab I-00179 Rome Italy Univ Inst Motor Sci Dept Educ Motor Activ & Sport I-00194 Rome Italy

Mirror neurons in the monkey's premotor cortex respond during both execution and observation of actions and are thought to be critical for understanding others' actions. Human studies have shown premotor cortex activation while viewing actions, hearing their sounds, listening to or reading action-related sentences, and have compared execution and observation of similar actions. However, we still lack direct evidence in humans of the most striking and theoretically relevant feature of mirror neurons, i.e., that they map seen/heard actions onto motor representations of the same actions at an abstract level. Here we combine fast event-related functional magnetic resonance imaging with an unconscious semantic priming paradigm and show that the human auditory mirror system also holds an abstract representation of the meaning of heard actions. We analyzed the effect on brain activity of trial-by-trial semantic congruency between a target sound denoting a hand or mouth action ( or an environmental event) and a briefly flashed written word acting as an unconscious cross-modal prime. Left inferior frontal and posterior temporal regions selectively responded to action sounds in a non-somatotopic fashion and were modulated by semantic congruency only in action sound trials. We also observed regions selective for either hand or mouth actions, which however did not show a corresponding effector-specific effect of semantic congruency. These results provide evidence that the human mirror system represents the meaning of actions ( but not of other events) ( a) at an abstract, semantic level, (b) independently of the effector, and ( c) independently of conscious awareness. (c) 2007 Elsevier Inc. All rights reserved.

关键词： Acoustic Stimulation Adult Auditory Perception/physiology Cues Discrimination (Psychology) Echo-Planar Imaging Female Functional Laterality/physiology Hand/physiology Humans image processing, computer-assisted Male Motor Cortex/physiology Mouth/physiology Movement/physiology Psychomotor Performance/physiology

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Manual and automated measures of superior temporal gyrus asymmetry: Concordant structural predictors of verbal ability in children

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NEUROimage 2008年第3期41卷 813-822页

作者： Eckert, Mark A. Lombardino, Linda J. Walczak, Adam R. Bonihla, Leonardo Leonard, Christiana M. Binder, Jeffrey R. Med Univ S Carolina Dept Otolaryngol Head & Neck Surg Charleston SC USA Univ Florida Dept Commun Sci & Disorders Gainesville FL 32611 USA Med Univ S Carolina Dept Commun Sci & Disorders Charleston SC USA Univ Florida McKnight Brain Inst Gainesville FL 32611 USA Med Coll Wisconsin Dept Neurol Milwaukee WI USA

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. (C) 2008 Elsevier Inc. All rights reserved.

关键词： Adolescent Adult Aged Brain Mapping/methods Brain Mapping/methods Child Female Functional Laterality/physiology Humans image processing, computer-assisted Male Middle Aged Temporal Lobe/anatomy & histology Temporal Lobe/physiology Verbal Behavior/physiology

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3D characterization of brain atrophy in Alzheimer's disease and mild cognitive impairment using tensor-based morphometry

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NEUROimage 2008年第1期41卷 19-34页

作者： Hua, Xue Leow, Alex D. Lee, Suh Klunder, Andrea D. Toga, Arthur W. Lepore, Natasha Chou, Yi-Yu Brun, Caroline Chiang, Ming-Chang Barysheva, Marina Jack, Clifford R., Jr. Bernstein, Matt A. Britson, Paula J. Ward, Chadwick P. Whitwell, Jennifer L. Borowski, Bret Fleisher, Adam S. Fox, Nick C. Boyes, Richard G. Barnes, Josephine Harvey, Danielle Kornak, John Schuff, Norbert Boreta, Lauren Alexander, Gene E. Weiner, Michael W. Thompson, Paul M. Univ Calif Los Angeles Sch Med Dept Neurol Lab Neuro Imaging Los Angeles CA 90095 USA Mayo Clin Coll Med Rochester MN USA Univ Calif San Diego Dept Neurosci La Jolla CA USA UCL Inst Neurol Dementia Res Ctr London England UC Davis Sch Med Dept Publ Hlth Sci Davis CA USA UC San Francisco Dept Radiol San Francisco CA USA UC San Francisco Dept Epidemiol & Biostat San Francisco CA USA UC San Francisco Dept Med & Psychiat San Francisco CA USA Dept Vet Affairs Med Ctr San Francisco CA USA Univ Arizona Dept Psychol Tucson AZ 85721 USA Univ Arizona Evelyn F McKnight Brain Inst Tucson AZ USA

Tensor-based morphometry (TBM) creates three-dimensional maps of disease-related differences in brain structure, based on nonlinearly registering brain MRI scans to a common image template. Using two different TBM designs (averaging individual differences versus aligning group average templates), we compared the anatomical distribution of brain atrophy in 40 patients with Alzheimer's disease (AD), 40 healthy elderly controls, and 40 individuals with amnestic mild cognitive impairment (aMCI), a condition conferring increased risk for AD. We created an unbiased geometrical average image template for each of the three groups, which were matched for sex and age (mean age: 76.1 years+/- 7.7 SD). We warped each individual brain image (N = 120) to the control group average template to create Jacobian maps, which show the local expansion or compression factor at each point in the image, reflecting individual volumetric differences. Statistical maps of group differences revealed widespread medial temporal and limbic atrophy in AD, with a lesser, more restricted distribution in MCI. Atrophy and CSF space expansion both correlated strongly with Mini-Mental State Exam (MMSE) scores and Clinical Dementia Rating (CDR). Using cumulative p-value plots, we investigated how detection sensitivity was influenced by the sample size, the choice of search region (whole brain, temporal lobe, hippocampus), the initial linear registration method (9-versus 12-parameter), and the type of TBM design. In the future, TBM may help to (1) identify factors that resist or accelerate the disease process, and (2) measure disease burden in treatment trials. (c) 2008 Elsevier Inc. All rights reserved.

关键词： Aged Aged, 80 and over Algorithms Alzheimer Disease/pathology Alzheimer Disease/psychology Atrophy Brain/pathology Brain Mapping Brain Mapping Cognition Disorders/pathology Cognition Disorders/psychology Female Humans image processing, computer-assisted Magnetic Resonance Imaging Male Middle Aged Neuropsychological Tests Psychiatric Status Rating Scales

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The electrical properties of high dilutions

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HOMEOPATHY 2008年第3期97卷 111-112页

作者： Smith, Cyril W. 36 Westminster Rd Ellesmere Pk Manchester M30 9EA Lancs England

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Nicotine-induced nystagmus correlates with midpontine activation

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NEUROimage 2008年第2期41卷 479-482页

作者： Deutschlaender, Angela Stephan, Thomas Riedel, Eva Zingler, Vera C. Huefner, Katharina Wiesmann, Martin Pierrot-Deseilligny, Charles Strupp, Michael Brandt, Thomas Univ Munich Klinikum Grosshadern Dept Neurol D-81377 Munich Germany Univ Munich Klinikum Grosshadern Dept Neuroradiol D-81377 Munich Germany Grp Hosp Pitie Salpetriere Serv Neurol 1 F-75634 Paris France

The pathomechanism of nicotine-induced nystagmus (NIN) is unknown. The aim of this study was to delineate brain structures that are involved in NIN generation. Eight healthy volunteers inhaled nicotine in darkness during a functional magnetic resonance imaging (fMRI) experiment;eye movements were registered using video-oculography. NIN correlated with blood oxygen level-dependent (BOLD) activity levels in a midpontine site in the posterior basis pontis. NIN-induced midpontine activation may correspond to activation of the dorsomedial pontine nuclei and the nucleus reticularis tegmenti pontis, structures known to participate in the generation of multidirectional saccades and smooth pursuit eye movements. (C) 2008 Elsevier Inc. All rights reserved.

关键词： Adult Brain Mapping Brain Mapping Female Ganglionic Stimulants/pharmacology Humans image processing, computer-assisted Magnetic Resonance Imaging Male Middle Aged Nicotine/pharmacology Nystagmus, Pathologic/chemically induced Pons/drug effects Pons/physiology

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Structure and Functional Role of Dynein's Microtubule-Binding Domain

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SCIENCE 2008年第5908期322卷 1691-1695页

作者： Carter, Andrew P. Garbarino, Joan E. Wilson-Kubalek, Elizabeth M. Shipley, Wesley E. Cho, Carol Milligan, Ronald A. Vale, Ronald D. Gibbons, I. R. Univ Calif San Francisco Howard Hughes Med Inst San Francisco CA 94158 USA Univ Calif San Francisco Dept Cellular & Mol Pharmacol San Francisco CA 94158 USA Univ Calif Berkeley Dept Mol & Cell Biol Berkeley CA 94720 USA Scripps Res Inst Dept Cell Biol La Jolla CA 92037 USA

Dynein motors move various cargos along microtubules within the cytoplasm and power the beating of cilia and flagella. An unusual feature of dynein is that its microtubule- binding domain ( MTBD) is separated from its ring- shaped AAA+ adenosine triphosphatase ( ATPase) domain by a 15- nanometer coiled- coil stalk. We report the crystal structure of the mouse cytoplasmic dynein MTBD and a portion of the coiled coil, which supports a mechanism by which the ATPase domain and MTBD may communicate through a shift in the heptad registry of the coiled coil. Surprisingly, functional data suggest that the MTBD, and not the ATPase domain, is the main determinant of the direction of dynein motility.

关键词： Adenosine Triphosphate/metabolism Amino Acid Sequence Animals Binding Sites Crystallization Crystallography, X-Ray Dimerization Dynein ATPase/chemistry Dynein ATPase/metabolism Hydrophobicity image processing, computer-assisted Mice Microscopy, Electron Microtubules/metabolism Microtubules/ultrastructure Models, Molecular Molecular Sequence Data Movement Protein Structure, Secondary Protein Structure, Tertiary Recombinant Fusion Proteins/chemistry Recombinant Fusion Proteins/metabolism

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Identifying natural images from human brain activity

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NATURE 2008年第7185期452卷 352-U7页

作者： Kay, Kendrick N. Naselaris, Thomas Prenger, Ryan J. Gallant, Jack L. Univ Calif Berkeley Dept Psychol Berkeley CA 94720 USA Univ Calif Berkeley Helen Wills Neurosci Inst Berkeley CA 94720 USA Univ Calif Berkeley Dept Phys Berkeley CA 94720 USA

A challenging goal in neuroscience is to be able to read out, or decode, mental content from brain activity. Recent functional magnetic resonance imaging ( fMRI) studies have decoded orientation(1,2), position(3) and object category(4,5) from activity in visual cortex. However, these studies typically used relatively simple stimuli ( for example, gratings) or images drawn from fixed categories ( for example, faces, houses), and decoding was based on previous measurements of brain activity evoked by those same stimuli or categories. To overcome these limitations, here we develop a decoding method based on quantitative receptive- field models that characterize the relationship between visual stimuli and fMRI activity in early visual areas. These models describe the tuning of individual voxels for space, orientation and spatial frequency, and are estimated directly from responses evoked by natural images. We show that these receptive- field models make it possible to identify, from a large set of completely novel natural images, which specific image was seen by an observer. Identification is not a mere consequence of the retinotopic organization of visual areas;simpler receptive- field models that describe only spatial tuning yield much poorer identification performance. Our results suggest that it may soon be possible to reconstruct a picture of a person's visual experience from measurements of brain activity alone.

关键词： Brain/physiology Brain Mapping/methods Brain Mapping/methods Humans image processing, computer-assisted Magnetic Resonance Imaging Nature Photic Stimulation Photography Research Design Visual Perception/physiology

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Characterizing Forest Fragments in Boreal, Temperate, and Tropical Ecosystems

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AMBIO 2008年第7-8期37卷 569-576页

作者： Meddens, Arjan J. H. Hudak, Andrew T. Evans, Jeffrey S. Gould, William A. Gonzalez, Grizelle Univ Idaho Dept Geog Moscow ID 83844 USA US Forest Serv USDA Rocky Mt Res Stn Moscow ID 83843 USA US Forest Serv USDA Int Inst Trop Forestry Rio Piedras PR 00926 USA

An increased ability to analyze landscapes in a spatial manner through the use of remote sensing leads to improved capabilities for quantifying human-induced forest fragmentation. Developments of spatially explicit methods in landscape analyses are emerging. In this paper, the image delineation software program eCognition and the spatial pattern analysis program FRAGSTATS were used to quantify patterns of forest fragments on six landscapes across three different climatic regions characterized by different moisture regimes and different influences of human pressure. Our results support the idea that landscapes with higher road and population density are more fragmented;however, there are other, equally influential factors contributing to fragmentation, such as moisture regime, historic land use, and fire dynamics. Our method provided an objective means to characterize landscapes and assess patterns of forest fragments across different forested ecosystems by addressing the limitations of pixel-based classification and incorporating image objects.

关键词： Caribbean Region Ecosystem Ecosystem Geographic Information Systems Geography Humans image processing, computer-assisted Models, Biological North America Population Density Satellite Communications Trees Tropical Climate

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