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during用法及时态1. "During 可以用来表示在某个时间段内呀，就像你在暑假期间做了好多有趣的事，比如‘During the summer vacation, I went swimming every day.’（在暑假期间，我每天都去游泳。
）想想看，这段时间你是不是有特别的经历呢？"2. "嘿，你们知道吗，During 还可以强调在一件事情正在进行的时候呀！比如说，‘During the meeting, he kept silent.’（在会议期间，他一直保持沉默。
）这是不是很形象呢？就像你专注于做一件事的时候一样呢！"3. "哇塞，During 能表达的意思可多啦！当我们说‘During the trip, we saw many beautiful scenery.’（在旅行期间，我们看到了许多美丽的风景。
）这不就是我们享受过程的时候嘛，多有意思呀，对吧！"4. "哎呀，During 用在描述过去的事情上也超棒呀！像是‘During my childhood, I played a lot of games.’（在我童年期间，我玩了好多游戏。
）大家想想自己童年时候的那些美好时光呀！"5. "你们想想，‘During the concert, the audience was completely absorbed.’（在音乐会期间，观众们完全沉浸其中。
）During 是不是让这个场景一下子就生动起来了呀，难道你们不这样觉得吗？"6. "其实呀，During 在很多时候都能让我们的表达更准确呢！就像‘During the film, I was so moved.’（在看电影期间，我非常感动。
）它就像一把钥匙，能打开清晰描述的大门呀！"结论：During 真的是一个非常实用且有趣的词呀，能让我们更好地表达不同时间段内发生的事情呢！。
介词后面一般有名词、代词或相当于名词的其他词类、短语或从句作它的宾语，表示与其他成分的关系。
介词和它的宾语构成介词词组，在句中作状语，表语，补语，定语或介词宾语。
介词可以分为时间介词、地点介词、方式介词、原因介词、数量介词和其他介词。
1.简单介词，包括in，on，with，by，for，at，about，under，of等。
2.重叠介词，from among 从...当中，from behind 从...后面，until after 直至...之后，at about 在大约...，after about 在大约...之后等3.短语介词，一个或两个简单介词和一个或几个其他词类构成一个短语，作用相当于一个介词，这就叫做短语介词。
这类介词的末尾总是一个简单介词，如 according to，because of，by means of，in addition to，in front of， in spite of，into等。
4.分词介词，有极少数介词的词尾是“-ing”，形似现在分词（其中也有些可做分词）。
常用的有：considering，regarding，respecting，including。
5.按词义分，表示“地点（包括动向）”的有：about around（在...附近、周围），above(高于、在...斜上方)，across(在...对面、横过)......主要用途，表示时间：1、表示在某时间，常用介词at，on，in等。
用 at 来表示在某一段时刻：at dawn/daybreak：在黎明，at six ：在6点钟，at midnight ：在午夜，at 4:30 ：在4点30分，at 来表示在……岁时，at sixteen/at the age of sixteen ：16岁的时候，用 on 来表示在星期几/某日，on Monday ：在星期一，on January fifth：在1月5日，on Christmas Day ：在圣诞节那一天也可用at Christmas，on New Year's Day：在新年那天，用in来表示一天中的早中晚，月份，季节或年份in the morning/afternoon/evening，in January/February，in Spring，in 20142、表示期间常用介词during，for，over，within，throughout，from和to等。
我们成长的过程作文英语Title: The Journey of Our Growth。
Growing up is a journey that shapes us into the individuals we become. From childhood innocence to the complexities of adulthood, our growth is a multifaceted process influenced by various experiences and interactions.During childhood, we are like sponges, absorbing knowledge and experiences from the world around us. We learn to walk, talk, and interact with others. Every discovery, whether it's the joy of making a new friend or the frustration of a scraped knee, contributes to our growth. These early experiences lay the foundation for our future development.As we transition into adolescence, we navigate the turbulent waters of identity formation. We grapple with questions of who we are and who we want to become. Peer relationships become increasingly important as we seekacceptance and belonging. We experiment with different interests and hobbies, trying to find where we fit in the world. Along the way, we encounter challenges and setbacks that test our resilience and shape our character.The journey of growth is not without its obstacles. We face adversity, whether it's academic struggles, family issues, or personal insecurities. These challenges force us to confront our limitations and push beyond our comfort zones. It's through overcoming these obstacles that we learn resilience, perseverance, and the importance of resilience.Throughout this journey, we are influenced by the people around us family, friends, teachers, mentors. Their guidance and support provide us with the encouragement and resources we need to thrive. They offer perspective and wisdom, helping us navigate the complexities of life.As we reach adulthood, we begin to take ownership of our lives and decisions. We pursue higher education, career paths, and personal goals. We face the realities ofresponsibility and independence, learning to balance work, relationships, and self-care. With each milestone achieved, we gain confidence in our abilities and a deeper understanding of ourselves.But growth is not a linear process; it's filled with peaks and valleys, twists and turns. We encounter moments of doubt and uncertainty, where we question our path and purpose. Yet, it's often during these times of strugglethat we experience the most growth. We learn to embrace change and adapt to new circumstances, emerging stronger and more resilient than before.In conclusion, the journey of growth is a lifelong process filled with discovery, challenges, and transformation. From the innocence of childhood to the complexities of adulthood, each stage shapes us into the individuals we are meant to be. And though the path may be uncertain at times, the lessons learned along the way make the journey worthwhile.。
during的用法归纳好嘞，以下是为您创作的关于“during 的用法归纳”的文案：咱今天就来好好唠唠“during”这个词儿的用法。
先来说说“during”最常见的意思，它表示“在……期间；在……的时候”。
比如说，“During the summer vacation, I went to Beijing”（在暑假期间，我去了北京。
）这里的“during”就清晰地指出了时间范围。
“during”后面接的通常是一个表示时间段的名词，像“during the day”（在白天）、“during the week”（在这周）、“during my childhood”（在我的童年时期）等等。
我记得有一次，我去参加一个英语角活动。
有个小伙伴说：“I read a lot of books during last month” 旁边就有人纠正他说：“应该是‘I read a lot of books during the last month’ 少了‘the’可就不对啦！”这就是一个很典型的小错误。
通过这件小事儿，咱们就能更清楚地知道，“during”后面接表示特定时间段的名词时，一般要加上定冠词“the”。
再给您说个例子，“He was very busy during the meeting”（在会议期间，他非常忙。
）这里“during the meeting”明确了他忙碌的时间范围。
还有哦，“during”有时候还能和“all”一起用，比如说“During all these years, she has been very hardworking”（在这些年期间，她一直都非常努力。
）这就强调了整个时间段内的情况。
另外，“during”和“for”在某些情况下意思有点相似，但用法还是有区别的。
“for”后面通常接一段时间，比如“for three days”（三天），强调的是持续的时长；而“during”更侧重于强调在某个时间段内发生的事情。
描述童年的经历英文作文英文，During my childhood, I had a plethora of experiences that shaped who I am today. From the bustling streets of my hometown to the serene countryside where I spent my summers, each moment was filled with its own unique charm.One vivid memory from my childhood is the countless hours I spent playing hide-and-seek with my friends in the neighborhood. The thrill of finding the perfect hiding spot and the excitement of being found added an element of adventure to our days. We would hide behind bushes, climb trees, and sometimes even sneak into each other's houses, much to the dismay of our parents.Another cherished memory is the annual family trips we took to the beach. I can still recall the feeling of the warm sand between my toes and the salty breeze blowing through my hair as I built sandcastles with my siblings. Those carefree days filled with laughter and sunshine areetched in my mind forever.Of course, childhood wasn't all fun and games. There were also moments of fear and uncertainty, like the time I got lost in a crowded amusement park or when I had to stand up to a bully at school. But through these challenges, I learned valuable lessons about resilience and courage that have stayed with me into adulthood.Looking back, I realize how fortunate I was to have such a rich and diverse childhood. From exploring the great outdoors to forging lifelong friendships, those formative years laid the foundation for the person I am today.中文，在我的童年时期，我经历了许多事件，这些事件塑造了我今天的样子。
The Bliss of ChildhoodChildhood, a time of innocence and wonder, is a cherished phase of life that eternally holds a specialplace in our hearts. It is a period of boundless imagination, filled with laughter, games, and an unwavering belief in the magic of the world.During childhood, the days seemed endless, filled with adventures and explorations. Simple pleasures like playingin the mud, climbing trees, or catching butterflies were sources of immense joy. The world was a vast playground, filled with mysteries to be uncovered and wonders to behold. The relationships formed during childhood are often the most纯真无邪的. Friends were chosen not based on social status or appearance, but simply because they shared the same interests and sense of fun. These friendships, often forged through shared experiences and antics, became the strongest bonds that lasted throughout life.Moreover, childhood is a time of learning and discovery. Children are natural explorers, constantly asking questions and seeking answers. They are eager to learn about theworld, and their curiosity leads them to explore every corner of their surroundings. This thirst for knowledge and understanding shapes their perspectives and influencestheir growth.However, as we grow older, the innocence and wonder of childhood often fade away. The responsibilities and complexities of adult life can overshadow the joy and simplicity of our early years. Nevertheless, the memories of childhood remain etched in our minds, serving as a reminder of the pure happiness and freedom we once knew.Looking back, childhood appears as a golden era, a time when life was uncomplicated and filled with dreams. It is a period that we long to revisit, even if it's just in our imaginations. The lessons learned, the friendships formed, and the memories created during this phase of life are treasures that we carry with us forever.In conclusion, childhood is a blissful time that shapes our personalities and influences our lives in indelible ways. It is a time of innocence, wonder, learning, and discovery that deserves to be cherished and remembered. As we move forward in life, let us hold these cherishedmemories close to our hearts and never forget the joy and freedom that childhood brought us.**童年的幸福时光**童年，那段充满纯真与好奇的时光，永远在我们心中占据着特殊的位置。
childhood 托福口语Childhood MemoriesChildhood is a precious phase in everyone's life, filled with innocence, joy, and unforgettable memories. It is a time when we are free from the responsibilities and worries of adulthood, and can fully immerse ourselves in the wonders of the world. In this article, we will explore the various aspects of childhood and the significant impact it has on shaping our lives.1. Exploration and CuriosityDuring childhood, we are naturally driven by an insatiable curiosity about the world around us. Whether it is the vibrant colors of a blooming flower, the texture of sand between our fingers at the beach, or the taste of our favorite ice cream, everything becomes a fascinating adventure. This innate curiosity sparks our desire to explore, learn, and discover new things, turning each day into a thrilling journey of knowledge.2. Imagination and CreativityChildhood is a time when imagination knows no bounds. From building elaborate forts out of furniture to transforming mundane objects into magical artifacts, children possess an unparalleled ability to create their own worlds. The power of imagination allows them to dream big, fostering creativity that can extend into adulthood. It is during this time that many individuals discover their passion for arts, music, or literature, igniting a lifelong love for creativity.3. Playtime and FriendshipsOne of the most cherished aspects of childhood is the joy of playtime. Children have boundless energy, and their days are filled with laughter, games, and endless fun. Whether it is playing tag in the park, making sandcastles at the beach, or engaging in imaginative role-playing, playtime serves as a platform for developing social skills and forming lifelong friendships. These childhood friendships often lay the foundation for future relationships and teach valuable lessons about empathy, cooperation, and conflict resolution.4. Unburdened by ResponsibilitiesAs children, our primary focus is on having fun and enjoying life to the fullest. We are unburdened by the pressures of adulthood, such as managing finances, building a career, or taking care of a family. Childhood allows us to revel in the present moment and embrace the enchantment that surrounds us. It is a blissful break from the worries and responsibilities that come later in life.5. Shaping Our Values and BeliefsChildhood experiences significantly influence our values, beliefs, and attitudes as adults. The lessons we learn during this formative period shape our character and often determine the paths we choose to follow. Whether it is the teachings of our parents, the influence of our peers, or the impact of significant life events, childhood becomes the building block of our moral compass.6. Nurturing a Sense of WonderThe world is a magical place through the eyes of a child. Everything seems extraordinary, from a butterfly fluttering its wings to a rainbow stretching across the sky. Childhood nurtures a sense of wonder and awe that allows us to appreciate the beauty in the simplest of things. This appreciation stays with us throughout our lives, reminding us to find joy in the small moments and appreciate the wonders that surround us.ConclusionChildhood is a time of extraordinary growth, exploration, and joy. It is a period that shapes our values, nurtures our creativity, and forms lifelong friendships. The memories created during childhood leave an indelible mark on our lives, reminding us to embrace curiosity, imagination, and the sense of wonder that make life truly meaningful. Let us cherish these memories and carry the essence of childhood within us, even as we grow older.。
关于childhood主题的英语作文Childhood is a precious time in our lives that shapes who we become as adults. It is a time of innocence, curiosity, and wonder. As children, we are free from the responsibilities and worries that come with adulthood, allowing us to explore and learn about the world around us.During childhood, we are constantly learning and developing. Our brains are like sponges, soaking up new information and experiences. We learn to walk, talk, and interact with others. We develop our personalities and form friendships that can last a lifetime.Childhood is also a time of imagination and creativity. We are not yet constrained by the rules and expectations of society, so we are free to let our imaginations run wild. We create make-believe worlds, play imaginary games, and dream of all the things we want to become when we grow up.As we grow older, we often look back on our childhood with nostalgia. We long for the carefree days of playing outside until the streetlights came on, building forts out of blankets, and having sleepovers with our friends. It isa time of innocence and simplicity that is often lost as we become adults.In conclusion, childhood is a magical time in our lives that shapes who we become as adults. It is a time of learning, growth, and exploration. It is a time of imagination and creativity. It is a time that we often look back on with fond memories and nostalgia.童年是我们生活中宝贵的时间，它塑造了我们成年后的样子。
年龄对比英文作文Title: A Comparative Analysis of Age。
Introduction:Age is a fundamental aspect of human existence, influencing various facets of life ranging from physical capabilities to societal roles. In this essay, we delveinto the significance of age through a comparative lens, exploring its implications across different stages of life.Childhood:During childhood, age serves as a marker of developmental milestones and educational progression. Young children typically experience rapid physical and cognitive growth, marked by milestones such as learning to walk, talk, and read. Age determines entry into formal education systems, with children progressing through grade levels based on their age cohort. Additionally, societalperceptions often shape expectations regarding behavior and abilities corresponding to specific age groups.Adolescence:The adolescent stage is characterized by significant physical, emotional, and social changes, with age playing a crucial role in navigating this transition. Adolescents undergo puberty, marked by hormonal changes that influence physical appearance and emotional well-being. Age determines eligibility for activities such as driving, voting, and employment, symbolizing increasing levels of autonomy and responsibility. Furthermore, peerrelationships and social dynamics often revolve around age similarities, shaping identities and group affiliations.Adulthood:Adulthood encompasses a broad spectrum of life stages, from early adulthood to middle and late adulthood, each influenced by age in distinct ways. Early adulthood is often associated with establishing independence, pursuinghigher education or career goals, and forming intimate relationships. Age-related milestones such as marriage, parenthood, and career advancement mark significant transitions during this stage. Middle adulthood is characterized by stability and productivity, with individuals typically focused on career advancement, financial stability, and family responsibilities. Late adulthood, or old age, is associated with declining physical health, retirement, and reflections on life achievements.Elderly:Old age brings unique challenges and opportunities, with age serving as a predictor of health outcomes and societal perceptions of aging. Elderly individuals may face age-related health conditions such as arthritis, dementia, and cardiovascular diseases, necessitating specialized healthcare and support services. Ageism, or discrimination based on age, remains a prevalent issue in society, affecting employment opportunities, healthcare access, and social inclusion for older adults. However, old age alsooffers opportunities for leisure, wisdom, and intergenerational connections, highlighting the diverse experiences associated with aging.Conclusion:In conclusion, age serves as a multifaceted aspect of human experience, influencing development, societal roles, and perceptions across the lifespan. From childhood through old age, age-related factors shape individuals' experiences, opportunities, and interactions with the world around them. Understanding the significance of age allows for greater insight into human development and the complexities ofaging in contemporary society.。
Maturation of White Matter is Associated with the Development of Cognitive Functionsduring ChildhoodZoltan Nagy,Helena Westerberg,and Torkel Klingberg Abstract&In the human brain,myelination of axons continues until early adulthood and is thought to be important for the development of cognitive functions during childhood.We used diffusion tensor MR imaging and calculated fractional aniso-tropy,an indicator of myelination and axonal thickness,in children aged between8and18years.Development of working memory capacity was positively correlated with fractional anisotropy in two regions in the left frontal lobe,including a region between the superior frontal and parietal cortices.Reading ability,on the other hand,was only correlated with fractional anisotropy in the left temporal lobe,in the same white matter region where adults with reading disability are known to have lower fractional anisotropy.Both the temporal and the frontal regions were also correlated with age.These results show that maturation of white matter is an important part of brain maturation during childhood,and that maturation of relatively restricted regions of white matter is correlated with development of specific cognitive functions.&INTRODUCTIONOne of the most prolonged developmental processes in the human brain is the myelination of axons,which continues until the end of the second decade of life (Benes,1989;Yakovlev&Lecours,1967).The long-lasting development of the white matter is paralleled by the development of cognitive functions.Paul Flechsig (1920)was the first to demonstrate the regional differ-ences in myelination rate and suggested that this may underlie the development of different functions.How-ever,a direct correlation between the normal develop-ment of white matter structure and the improvement of cognitive functions has not been demonstrated.In the present study,we address this question using diffusion tensor imaging(DTI),an MR technique that has the ability to reveal microstructural properties of white matter.This technique is based on the fact that the diffusion of water in the white matter of the brain is anisotropic(Moseley et al.,1990),so that it is faster along the axons than perpendicular to them.The axonal membrane itself induces some of this directional pref-erence even without myelin(Gulani,Webb,Duncan,& Lauterbur,2001;Wimberger et al.,1995).However, myelination of the axons further increases the anisotro-py as shown in studies comparing anisotropy with his-tological findings(Wimberger et al.,1995),comparing anisotropy in normal mice with that in knockout mice lacking myelin(Gulani et al.,2001),as well as in human studies of demyelination(Werring,Clark,Barker,Thom-son,&Miller,1999).Conventional MR techniques have been used to mea-sure a gradual increase in white matter volume during childhood(De Bellis et al.,2001;Giedd,Blumenthal, Jeffries,Castellanos,et al.,1999;Paus et al.,1999;Sowell, Thompson,Holmes,Jernigan,&Toga,1999;Caviness, Kennedy,Richelme,Rademacher,&Filipek,1996;Reiss, Abrams,Singer,Ross,&Denckla,1996;Pfefferbaum et al., 1994)based on the measurement of T1signal.Although informative,these MR studies could not identify micro-structural properties of white matter such as axonal directions.Previously,DTI has been used to find age-related changes in anisotropy during childhood(Schmi-thorst,Wilke,Dardzinski,&Holland,2002;Mukherjee et al.,2001;Klingberg,Vaidya,Gabrieli,Moseley,&Hede-hus,1999),but behavioral measures were not included in these studies.We measured two different cognitive functions:visuo-spatial working memory(WM)and reading ability.De-velopment of these functions continues throughout childhood but depend on different parts of the brain. By using two different cognitive functions we had the possibility to demonstrate some specificity of maturation (e.g.,that maturation of a white matter region is more associated with development of one function and less with another).WM is most closely related to the function of the dorsolateral prefrontal cortex.The particular WM task we used(Figure1)is based on a task that has previously been used to study the development of WMKarolinska Institute,Astrid Lindgren Children’s HospitalD2004Massachusetts Institute of Technology Journal of Cognitive Neuroscience16:7,pp.1227–1233capacity in children(Westerberg,Hirvikoski,Forssberg, &Klingberg,in press;Hale,Bronik,&Fry,1997).We have also used this task in a previous functional MRI study in children,in which development of WM capacity was found to correlate with increased cortical activity in the left superior frontal and left intraparietal cortices (Klingberg,Forssberg,&Westerberg,2002).A later study of development of WM confirmed these findings(Kwon, Reiss,&Menon,2002).In the present study,we thus hypothesized that we would find maturational changes in white matter close to these frontal and parietal re-gions,or in the white matter connecting them. Development of reading ability is associated with changes in cortical activity in temporo-parietal,tem-poro-occipital,and ventral frontal regions(Turkeltaub, Gareau,Flowers,Zeffiro,&Eden,2003;Shaywitz et al., 2002).In a previous DTI study,it was found that reading ability,as measured by the word-ID task from the Woodcock test battery,correlated with white matter integrity in the left temporo-parietal region(Klingberg et al.,2000).In this region,adult subjects with reading disability had impaired integrity of white matter com-pared with controls.Furthermore,both within the reading impaired group and within the control group there was a positive correlation between reading ability and white matter structure.Given these results,we hypothesized that development of reading ability might be dependent on white matter structure in the temporo-parietal region.If such developmental trend could be detected,this might also provide insight into the possible mechanisms underlying developmen-tal dyslexia.Variability in white matter structure in a population of children could be divided into that related to differ-ences in maturation,on the one hand,and interindi-vidual variability on the other.Maturation can only partly be explained by the age of a child.Furthermore, even within the same individual,different cognitive functions could mature at different rates.A measure of cognitive function would thus provide a better measure of maturation than age.Our approach was to study children and adolescents(aged8–18years)with the underlying assumption that variability in cognitive function would mainly be determined by differences in maturation.In a separate analysis,we also used age as a covariate.RESULTSTwenty-three healthy,right-handed children(14boys, 9girls),aged7.8–18.5years(mean11.9years,SD3.1), performed the reading and the WM tasks(Figure1) and then underwent MR scanning.Fractional anisotropy (FA)was used as an index of white matter maturation. Analyses were conducted by correlating the behavioral variable with FA in each white matter voxel in the brain using SPM99(Friston et al.,1995).When FA was correlated with WM scores,significant correlations (p<.001)were found in two regions in the left frontal lobe(Figure2A–B,Table1),consistent with our hypo-thesis.Significant correlations were also found in the anterior corpus callosum,which connects the frontal lobes(Figure2C).In addition,there was a correlation in the left temporo-occipital white matter(not shown), which was not predicted in our hypothesis.Reading time correlated negatively with FA values only in a single cluster,located in the left temporal lobe(p<.001, Figure2D,Table1).In the analyses above,a stringent statistical threshold was used(t>2.52;cluster size>230voxels;p<.001). With a more lenient threshold(t>2.52;cluster size> 120voxels;p<.05),there were two additional clusters that correlated with WM.These were located in the right superior fronto-parietal region(x=15,y=À14,z= 62)and in the left occipito-temporal region(x=À36, y=À70,z=2).FA values from the clusters in Table1were subse-quently extracted from the most significant voxel in each cluster and plotted against the behavioral scores.The correlation was.54for the superior fronto-parietal,.55 for the inferior frontal,.61for the corpus callosum,.58 for the occipito-temporal,and.44for the temporal cluster(Figure3A–D).There were no significant differ-ences in FA between boys and girls in any of the clustersFigure1.Schematic drawing of the visuospatial WMtask.1228Journal of Cognitive Neuroscience Volume16,Number7related to WM(left superior fronto-parietal p=.31;left inferior frontal p=.50;corpus callosum p=.29; temporo-occipital p=.09)or reading ability(left tem-poral p=.36).Visual inspection suggested that one of the subjects in Figure3D was an outlier.However,this was the youngest subject(7.8years),and it was there-fore to be expected that the child would also be the slowest reader.However,we made a confirmatory SPM analysis without this subject(n=22),in which we still found a significant correlation between reading and FA in the same location(p<.05).Furthermore,correla-tions between behavior and the extracted FA values were significant also using nonparametric methods (Spearman rank-correlation,p<.001for each cluster). The extent of fiber pathway organization can be estimated by coherence measures(Basser&Pierpaoli, 1996).We measured the average angle between the direction of diffusion in a given voxel and the direction of diffusion in all its neighbors.Coherence images were calculated and normalized for each subject and statisti-cal analyses identical to those done on the FA images were performed.However,these analyses did not re-sult in any significant clusters that overlapped with the clusters of the FA analysis.With this method,therewas Figure2.Regions of significant correlations between white matter anisotropy and cognitive performance.(A–C)Correlation between WMscore and anisotropy.(D)Correlation between reading ability and anisotropy.The clusters are overlaid on the mean FA image from all23subjects, and each slice is through the most significant voxel of the cluster.(A)Left superior frontal lobe,extending into the parietal lobe.(B)Left inferior frontal lobe.(C)Genu of corpus callosum.(D)Left temporal lobe.(E)Main direction of diffusion in the region from(D).The colors red,blue, and green indicate anterior–posterior,left–right,and superior–inferior diffusion directions,respectively.The white lines mark the contour ofthe cluster correlated with reading ability.Nagy,Westerberg,and Klingberg1229therefore no indication that fiber organization affected the correlation between FA and behavior.The Effect of AgeIn a separate analysis,we used age as a covariate in the WM and reading analyses,to see what correlations between cognitive test score and FA that remained significant after removing variability due to age.The regions that remained significant(p<.05)are marked with an asterisk in Table1.DISCUSSIONIn this study,we show that development of cognitive abilities during the later part of childhood is correlated with maturation of white matter.The improvement ofTable1.Regions Where FA Values Correlated with Cognitive Test ScoresTest Significant Clusters Corrected p Value Cluster Size(mm3)Coordinates(x,y,z)a Working memory Superior fronto-parietal(L)<0.0011026(À15,À22,54) Inferior frontal(L)*<0.0011175(À26,28,3)Anterior corpus callosum*<0.001918(14,27,9)Temporo-occipital(L)*<0.001999(À46,À48,0) Reading Temporal(L)<0.001800(À27,À28,6)L=left.a Talairach space in units of millimeters.*Clusters with statistical significance after the effect of age is removed(p<.05).Figure3.FA values and behavioral scores fromthe clusters shown inFigure2A–D.Each point represents one individual.(A)Left superior fronto-parietal.(B)Left inferior frontal.(C)Genu of corpus callosum.(D)Left temporallobe.1230Journal of Cognitive Neuroscience Volume16,Number7WM was associated with increased anisotropy in the superior and inferior left frontal lobe,whereas the development of reading ability only correlated with maturation of white matter in the left temporal lobe. The fact that white matter develops until late in child-hood has been shown in previous studies(Schmithorst et al.,2002;De Bellis et al.,2001;Mukherjee et al.,2001; Giedd,Blumenthal,Jeffries,Castellanos,et al.,1999; Klingberg et al.,1999;Paus et al.,1999;Sowell et al., 1999;Caviness et al.,1996;Reiss et al.,1996;Pfefferbaum et al.,1994).The present study extends these previous findings by showing the regional and functional speci-ficity of this maturation—with maturation of relatively restricted regions that are correlated with specific cog-nitive functions.Within the left superior fronto-parietal cluster(WM correlation)and the left temporal white matter cluster (reading correlation),the correlation with FA was not significant after the effect of age was removed(Table1). This shows that,for these regions,the relationship between behavior and FA is dependent on age,and therefore,actual childhood development.For other clus-ters(left inferior frontal,left occipito-temporal,corpus callosum),there remained a significant correlation be-tween WM and FA also after removing the effect of age. This remaining correlation could be due to interindivid-ual differences in WM capacity that are unrelated to maturation or to maturational differences that are not accounted for by age.The reading ability cluster is located about15mm inferior and medial to the center of the region where an age-related change in T1-weighted signal was found previously(Paus et al.,1999).Furthermore,the reading ability cluster in the present study overlaps with the inferior part of a region where a previous DTI study found disturbances of white matter structure in adult subjects with reading disabilities(Klingberg et al.,2000). The cluster is located in a region where some axons run in an anterior–posterior direction(Figure2E),which makes it possible that frontal and posterior language areas are connected by axons running through this region.The present result thus confirms the importance of this white matter region for reading ability,and ex-tends the previous findings by demonstrating the im-portance of late maturation of white matter in this region.Knowledge of the normal development could indicate possible mechanisms in developmental disor-ders,such as developmental dyslexia.A disturbance of maturation in the temporal lobe would,for example, result in lower FA in adults.Future studies of develop-ment in children with and without reading problems might be able to answer these questions.The regions where FA was correlated with WM capac-ity were mainly located within the frontal lobe.The white matter cluster in the superior part of the left frontal lobe is located about10mm medial and posterior to the cortical region in the superior frontal sulcus where development of visuospatial WM capacity and brain activity are correlated(Klingberg et al.,2002).It has also been shown that increased brain activity in the superior frontal cortex during childhood is correlated with improved performance on the Stroop task,a visual task requiring control of attention and response inhibi-tion(Adleman et al.,2002).Furthermore,it was recently shown that the FA in the superior frontal lobe is directly correlated with brain activity in the superior frontal sulcus and intraparietal cortex in children(Olesen,Nagy, Westerberg,&Klingberg,2003).The structural matura-tion of white matter in the superior frontal lobe that was identified in the present study could thus be an under-lying mechanism behind the increase in brain activity of the superior frontal cortex seen during development. The correlation between FA and WM capacity in the inferior frontal lobe was expected based on the knowl-edge about the involvement of the frontal lobe in WM, but the connectivity of this white matter region is unclear.The maturation of white matter in the corpus callosum presumably improves the communication be-tween the two frontal lobes.In the present study,FA in this region was significantly correlated with WM also after the effect of age was removed.Several prior studies have shown a correlation between white matter volume and age in the corpus callosum(De Bellis et al.,2001; Giedd,Blumenthal,Jeffries,Castellanos,et al.,1999). Consistent with the correlation to WM,there is evidence that the corpus callosum is affected in wide variety of childhood neuropsychiatric illnesses that involve impair-ments of WM and attention(Giedd,Blumenthal,Jeffries, Rajapakse,et al.,1999).Anisotropy of diffusion in the white matter could theoretically reflect several histological characteristics in addition to myelination and axonal diameter,includ-ing the number of axons per cross-sectional area,and the coherence,that is,how well organized or parallel the fibers are.However,the coherence analysis did not indicate any differences in coherence that could explain the FA results,although this method only measures the coherence between voxels.The use of more diffusion directions might resolve the question of intravoxel coherence and its relation to FA(Frank,2001).Because the number of axons does not increase after birth (LaMantia&Rakic,1990),the number of axons per cross-sectional area cannot explain the increase in FA during childhood.It is therefore more likely that the increase in FA is due to the increased diameter and myelination of axons during development.The amount of myelination and axonal thickness is directly related to each other(Waxman&Sims,1984),and these two phe-nomena are therefore difficult to separate in develop-mental studies.However,the physiological effects of increases in axon thickness and myelination are similar in that they both increase conduction speed.This could improve functionality by providing faster information transfer,and allowing a more precise timing in theNagy,Westerberg,and Klingberg1231communication between cortical areas.For the reading task,the crucial communication is presumably that be-tween language areas in the temporo-parietal region and the inferior frontal cortex,although the connectivity is still unclear and could also include connections between posterior brain areas.Dyslexic subjects have a lower correlation of activity between posterior and anterior language areas(Horwitz,Rumsey,&Donhue,1998), which could be explained by disturbances in white matter connecting these regions(Klingberg et al., 2000).During development,there is also increased activity in this network(Turkeltaub et al.,2003),which could fit with the improved communication suggested by the present results.For the WM task,it is possible that higher conduction speed affects performance by facilitating recurrent excitation of cortical areas underly-ing active maintenance of visuospatial information.The improved communication could lead to a more stable network that is more resistant to interference and thus loss of information.The present results show that the maturation of white matter affects cognitive functions.White matter matura-tion,in turn,may be affected by genetic pre-program-ming or by experience.There is evidence that activity in nerve cells promotes myelination of the axons(Stevens &Fields,2000).This provides a mechanism through which experience could affect myelination.It is still unclear,however,if these phenomena can be extended to the effect of experience on the human myelination to the degree that it can be detected by DTI. METHODSTasksIn the WM task,the child was asked to remember the location of red circles that were presented sequentially in a4Â4grid(Figure1).After presentation,the child indicated the correct locations by pointing to an empty grid on a touch screen.The number of circles that the child should remember was gradually increased.When the child failed two attempts on a level,the testing was stopped.The total number of correctly remembered circles was summed up and used as the child’s WM score.Only accuracy was of interest in this task.The subjects were not asked to respond as fast as possible and reaction times were not recorded.During the reading task,the children read aloud a list of20Swedish words as fast as possible,without sacri-ficing accuracy.The time it took to read the words was taken as the reading variable that was used in the analy-sis.Shorter reading time indicates better reading ability. MR ScanningDiffusion-weighted scanning was performed with a1.5-T General Electric Signa Echospeed scanner(Milwaukee,WI,USA)with a single-shot,echo-planar imaging se-quence,triggered with pulse gating with a delay of 300msec.Diffusion was measured in20noncollinear directions(b=1000sec/mm2).We also collected five non-diffusion-weighted images(b=0sec/mm2).Eigh-teen slices were acquired from each subject,with an in-plane resolution of1.72Â1.72mm and a slice thickness of5mm.Eddy current distortions and head movements were corrected(Andersson&Skare,2002)before the calculation of diffusion tensors.In each voxel,FA was calculated(Basser&Pierpaoli,1996).FA images were smoothed with a4-mm FWHM gaussian filter.From each subject,the mean of the five non-diffusion-weighted images was used to transform the anisotropy images to a common template in Talairach space,employing a set of linear and nonlinear transformation parameters,as implemented in the statistical software package SPM99 (Friston et al.,1995).Two statistical analyses were then performed,correlating FA in each voxel with WM or reading scores.We restricted the analysis to voxels with FA>0.15to focus on white matter,which has higher FA values than gray matter and cerebrospinal fluid.The p values in the SPM analyses were corrected for multiple comparison in the entire search volume,except in a second confirmatory analysis where one subject was excluded,in which there was a specific hypothesis about the location of the cluster.AcknowledgmentsWe thank Jesper Andersson and Stefan Skare of the MR-Center at Karolinska Institute in Stockholm,Sweden.This work was supported by the Swedish Research Council.Reprint requests should be sent to Torkel Klingberg,Kar-olinska Institute,Neuropediatric Unit,Astrid Lindgren Child-ren’s Hospital Q2:07,17176Stockholm,Sweden,or via e-mail: torkel.klingberg@kbh.ki.se.REFERENCESAdleman,N.E.,Menon,V.,Blasey,C.M.,White,C.D., Warsofsky,I.S.,Glover,G.H.,&Reiss,A.L.(2002).A developmental fMRI study of the Stroop color–word task.Neuroimage,16,61–75.Andersson,J.,&Skare,S.(2002).A model-based methodfor retrospective correction of geometric distortions in diffusion-weighted EPI.Neuroimage,16,200–216. 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