Magnetic resonance perfusion imaging in the study of language

This paper provides a brief review of various uses of magnetic resonance perfusion imaging in the investigation of brain/language relationships. The reviewed studies illustrate how perfusion imaging can reveal areas of brain where dysfunction due to low blood flow is associated with specific language deficits, and where restoration of blood flow to improve the tissue function results in recovery of those deficits. This sort of evidence helps to reveal areas of the brain that are essential to a particular language task. Other studies have provided clues regarding the mechanisms of early language recovery, or have shown how perfusion imaging can identify patients with chronic hypoperfusion due to cerebrovascular stenosis in whom the BOLD effect in fMRI may be absent or reduced in areas of neural activation.     

On the neurobiological investigation of language understanding in context

There are two significant problems in using functional neuroimaging methods to study language. Improving the state of functional brain imaging will depend on understanding how the dependent measure of brain imaging differs from behavioral dependent measures (the "dependent measure problem") and how the activation of the motor system may be confounded with non-motor aspects of processing in certain experimental designs (the "motor output problem"). To address these problems, it may be necessary to shift the focus of language research from the study of linguistic competence to the understanding of language use. This will require investigations of language processing in full multi-modal and environmental context, monitoring of natural behaviors, novel experimental design, and network-based analysis. Such a combined naturalistic approach could lead to tremendous new insights into language and the brain.     

脑成像技术及其在决策研究中的应用

先进的无创神经影像技术(如EEG和fMRI)允许研究者直接观察被试在完成多种知觉、运动和认知任务时的大脑活动。将脑功能成像与严密的实验设计和数据分析方法结合起来, 我们可以考察大脑不同脑区的功能以及它们之间的交互作用。随着脑功能成像技术在研究人类决策行为中的日益成功运用, 一个被称为神经经济学的新兴领域正在逐渐形成和发展起来。本文中首先对脑成像技术进行一个总体介绍, 重点在于探讨近年来在多体素分析和多模态数据整合的最新进展。接下来, 我们以风险决策、跨时间选择以及社会决策领域的几个研究为例, 阐述神经影像技术如何能加深和拓展我们对人类决策的认识。最后, 我们讨论了神经经济学中研究中面临的一些挑战以及未来的研究方向。     

How the ventral pathway got lost: and what its recovery might mean

Textbooks dealing with the anatomical representation of language in the human brain display two language-related zones, Broca's area and Wernicke's area, connected by a single dorsal fiber tract, the arcuate fascicle. This classical model is incomplete. Modern imaging techniques have identified a second long association tract between the temporal and prefrontal language zones, taking a ventral course along the extreme capsule. This newly identified ventral tract connects brain regions needed for language comprehension, while the well-known arcuate fascicle is used for "sensorimotor mapping" during speech production. More than 130 years ago, Carl Wernicke already described a ventral connection for language, almost identical to the present results, but during scientific debate in the following decades either its function or its existence were rejected. This article tells the story of how this knowledge was lost and how the ventral connection, and in consequence the dual system, fits into current hypotheses and how language relates to other systems.     

Imaging a science of mind

I believe that the study of neuroimaging has supported localization of mental operations within the human brain. Most studies have shown a small number of widely distributed brain areas that must be orchestrated to carry out a cognitive task. Although, as in all sciences, there are disagreements, the convergence of results in areas of attention and language in particular seem impressive. Moreover, the anatomical data has helped us to specify the computations that are used by the brain to carry out cognitive tasks. Building upon localization of cognitive operations, imaging methods are being applied to studies of the circuitry, plasticity and individual development of neural networks. Working together with cellular and genetic methods, there is movement towards a more unified view of the role of the human brain in supporting the mind.     

The Creative Brain/The Creative Mind

In the past few decades, neuroscience research has greatly expanded our understanding of how the human brain functions. In particular, we have begun to explore the basis of emotions, intelligence, and creativity. These brain functions also have been applied to various aspects of behavior, thought, and experience. We have also begun to develop an understanding of how the brain and mind work during aesthetic and religious experiences. Studies on these topics have included neuropsychological tests, physiological measures, and brain imaging. These different techniques have enabled us to open up a window into the brain. It is by understanding the functioning of the creative brain that we begin to understand the concept of the creative mind. It is through the use of emotions and other higher cognitive functions that the brain and mind can create ideas, music, literature, and ultimately our entire repertoire of behaviors. How these different creative abilities are derived can also be traced to various parts of the brain and how they function. Modern neuroscience allows us to begin to understand the creative aspect of the brain and mind and perhaps can take us one step further toward understanding the most profound types of aesthetic and religious experiences.     

Dynamic brain imaging: Event-related optical signal (EROS) measures of the time course and localization of cognitive-related activity

This paper describes the concept of dynamic brain imaging and introduces a new methodology, the event-related optical signal, or EROS. Dynamic brain imaging allows one to study noninvasively the time course of activity in specific brain areas. Brain imaging data can contribute to the analysis of the subcomponents of the human information processing system and of their interactions. Several brain imaging methods provide data that possess spatial and temporal resolution at various degrees and can be used for this purpose. In this paper, we focus on the EROS method, which yields data with millisecond temporal resolution and subcentimeter spatial resolution. We describe the fundamentals of this method and report several examples of the types of data that can be obtained with it. Finally, we discuss the possibility of combining different imaging methods, as well as the advantages and limitations that can be expected in this process.     

Functional brain mapping of extraversion and neuroticism: learning from individual differences in emotion processing

This review outlines how functional brain imaging, using an individual-differences approach in the processing of emotional stimuli, has begun to reveal the neural basis of extraversion (E) and neuroticism (N), two traits that are linked to both emotion and health. Studies using functional magnetic resonance imaging have shown that individual differences in participants' E and N scores are correlated with individual differences in brain activation in specific brain regions that are engaged during cognitive-affective tasks. Imaging studies using genotyped participants have begun to address the molecular mechanisms that may underlie these individual differences. The multidisciplinary integration of brain imaging and molecular genetic methods offers an exciting and novel approach for investigators who seek to uncover the biological mechanisms by which personality and health are interrelated.     

视觉词汇加工的动态神经网络及其形成

揭示大脑加工的神经网络机制成为认知神经科学研究的最新取向.本研究以视觉词汇加工脑区(VWFA)的神经功能作为切入点,探讨视觉词汇加工神经网络的动态机制及其形成.研究一考察VWFA在刺激驱动和任务调节下的动态激活,及其与语音、语义脑区所组成神经网络的动态机制.研究二通过跨文化对比以及儿童阅读发展研究,阐明语言经验对视觉词汇加工网络的塑造作用.研究三对比功能网络、静息网络以及白质纤维束联结,探讨视觉词汇加工网络的动态联结及其形成.研究结果有助于建构视觉词汇加工的神经生理模型,为基于脑科学的阅读教学和阅读障碍矫治奠定理论基础,为认知神经科学研究提供了新的思路.     

Does functional neuroimaging solve the questions of neurolinguistics?

Neurolinguistic research has been engaged in evaluating models of language using measures from brain structure and function, and/or in investigating brain structure and function with respect to language representation using proposed models of language. While the aphasiological strategy, which classifies aphasias based on performance modality and a few linguistic variables, has been the most stable, cognitive neurolinguistics has had less success in reliably associating more elaborately proposed levels and units of language models with brain structure. Functional imaging emerged at this stage of neurolinguistic research. In this review article, it is proposed that the often-inconsistent superfluity of outcomes arising from functional imaging studies of language awaits adjustment at both "ends" of the process: model and data. Assumptions that our current language models consistently and reliably represent implicit knowledge within human cerebral processing are in line for major revision; and the promise of functional brain imaging to reveal any such knowledge structures must incorporate stable correlates of the imaging signal as dependent variable.     

Should Psychology Ignore the Language of the Brain?

ABSTRACT— Claims that neuroscientific data do not contribute to our understanding of psychological functions have been made recently. Here I argue that these criticisms are solely based on an analysis of functional magnetic resonance imaging (fMRI) studies. However, fMRI is only one of the methods in the toolkit of cognitive neuroscience. I provide examples from research on event-related brain potentials (ERPs) that have contributed to our understanding of the cognitive architecture of human language functions. In addition, I provide evidence of (possible) contributions from fMRI measurements to our understanding of the functional architecture of language processing. Finally, I argue that a neurobiology of human language that integrates information about the necessary genetic and neural infrastructures will allow us to answer certain questions that are not answerable if all we have is evidence from behavior.     

Mapping gray matter development: Implications for typical development and vulnerability to psychopathology

Recent studies with brain magnetic resonance imaging (MRI) have scanned large numbers of children and adolescents repeatedly over time, as their brains develop, tracking volumetric changes in gray and white matter in remarkable detail. Focusing on gray matter changes specifically, here we explain how earlier studies using lobar volumes of specific anatomical regions showed how different lobes of the brain matured at different rates. With the advent of more sophisticated brain mapping methods, it became possible to chart the dynamic trajectory of cortical maturation using detailed 3D and 4D (dynamic) models, showing spreading waves of changes evolving through the cortex. This led to a variety of time-lapse films revealing characteristic deviations from normal development in schizophrenia, bipolar illness, and even in siblings at genetic risk for these disorders. We describe how these methods have helped clarify how cortical development relates to cognitive performance, functional recovery or decline in illness, and ongoing myelination processes. These time-lapse maps have also been used to study effects of genotype and medication on cortical maturation, presenting a powerful framework to study factors that influence the developing brain.     

Brain plasticity,learning, and developmental disabilities

This is a time of significant gains in methodological development for examining the developing human brain. New efforts are underway to unify the understanding of the development of brain anatomy with physiological, cellular and molecular processes that influence behavioral development. This special issue provides animal models of behavior and brain development, applications of noninvasive imaging and genetic methods to human brain development and behavior, and select reviews of how these models and methods have been applied to the examination of developmental disabilities. This issue reflects a sampling of current approaches to the study of brain plasticity, development and learning in typically and atypically developing humans and animals.     

The Changing Relationship Between Anatomic and Cognitive Explanation in the Neuropsychology of Language

Changing trends in the approach to neurolinguistics are reviewed. We suggest that these trends are marked by a distinct convergence between linguistic/cognitive and anatomic/physiological approaches to the study of aphasia. With respect to the former, we cite the refinement of analysis of language symptoms and the introduction of experimental methods that reveal real-time aspects of language processing. With respect to the latter, we cite the technical advances in static and dynamic brain imaging that have allowed the in vivo analysis of lesion sites in aphasic patients, and the identification of foci of metabolic activity during linguistic/cognitive tasks in normal brains. We cite recent imaging studies of category-specific lexical dissociations as examples of the productive convergence of anatomic and technological advances to illuminate a particularly challenging problem.     

Neuroscience and learning: lessons from studying the involvement of a region of cerebellar cortex in eyeblink classical conditioning

How the nervous system encodes learning and memory processes has interested researchers for 100 years. Over this span of time, a number of basic neuroscience methods has been developed to explore the relationship between learning and the brain, including brain lesion, stimulation, pharmacology, anatomy, imaging, and recording techniques. In this paper, we summarize how different research approaches can be employed to generate converging data that speak to how structures and systems in the brain are involved in simple associative learning. To accomplish this, we review data regarding the involvement of a particular region of cerebellar cortex (Larsell's lobule HVI) in the widely used paradigm of classical eyeblink conditioning. We also present new data on the role of lobule HVI in eyeblink conditioning generated by combining temporary brain inactivation and single-cell recording methods, an approach that looks promising for further advancing our understanding of relationships between brain and behavior.     

词汇歧义消解的脑机制

词汇歧义是语言歧义的一种, 词汇歧义消解受到相对意义频率和语境的影响。半视野研究发现大脑两半球都能在词汇歧义消解过程中根据语境信息选择性地激活歧义词的恰当意义、抑制不恰当意义, 其中左半球的语义选择功能更强; 脑损伤研究发现大脑左、右半球损伤都会导致词汇歧义消解中语义选择障碍, 词汇歧义消解需要大脑两半球的联合作用; 神经成像研究进一步发现额叶与颞叶共同支持词汇歧义消解, 歧义词的恰当意义的选择是由额下回执行的, 语义整合加工是由颞叶负责的。     

In search of the language switch: An fMRI study of picture naming in Spanish-English bilinguals

For many years, researchers investigating the brain bases of bilingualism have concentrated on two basic questions. The first concerns the nature of language representation. That is, are a bilinguals' two languages represented in distinct or overlapping areas of the brain. The second basic question in the neuropsychology of bilingualism concerns the neural correlates of language switching, that is, the areas that are active when bilinguals switch from one language to the other. Performance between single-language and dual-language picture naming was compared in a group of six Spanish-English bilinguals using behavioral measures and functional magnetic resonance imaging. Participants showed slower reaction times and increased activation in the dorsolateral prefrontal cortex in the mixed language condition relative to single language condition. There was no evidence that each language was represented in different areas of the brain. Results are consistent with the view that language switching is a part of a general executive attentional system and that languages are represented in overlapping areas of the brain in early bilinguals.     

聋人早期手语经验对脑功能及结构的塑造作用

语言经验对脑功能和结构发展有重要的塑造作用。然而, 目前的相关证据主要来自对脑损伤导致的失语症病人的语言康复、第二语言学习以及针对成人读者进行的语言训练等方面的研究。幼儿时期的早期语言经验对脑结构与功能发展的影响更加重要, 但直接的研究证据却相当缺乏。本文提出一个研究设想, 拟综合使用多种脑成像技术, 系统探讨有早期手语经验和无早期手语经验的聋人个体在脑皮层语言功能的组织及脑结构发育的差异, 包括语言任务中大脑语言区的激活模式, 静息状态下脑功能联结的默认网络特征, 脑皮层灰质密度, 以及神经纤维束发育状况等, 揭示早期语言经验对大脑功能和结构发育的塑造作用。     

Neuroscience and education

Neuroscience is a relatively new discipline encompassing neurology, psychology and biology. It has made great strides in the last 100 years, during which many aspects of the physiology, biochemistry, pharmacology and structure of the vertebrate brain have been understood. Understanding of some of the basic perceptual, cognitive, attentional, emotional and mnemonic functions is also making progress, particularly since the advent of the cognitive neurosciences, which focus specifically on understanding higher level processes of cognition via imaging technology. Neuroimaging has enabled scientists to study the human brain at work in vivo, deepening our understanding of the very complex processes underpinning speech and language, thinking and reasoning, reading and mathematics. It seems timely, therefore, to consider how we might implement our increased understanding of brain development and brain function to explore educational questions.