王毅研究员
YiWang,Professor

专家类别:研究员
简历&研究组工作摘要：
2000年日本大阪大学，理学博士
2000-2004年美国德克萨斯大学休斯敦医学院，博士后
2004至今中国科学院生物物理研究所，研究员，课题组长主要研究方向：物体视知觉与认知的神经机理。研究视皮层神经元的活动与视知觉、认知的相关性，物体亮度、颜色、形状、运动特征的编码和表达的脑机制。近期（06－07）主要工作和进展
在自然的视觉中，大多数情况下大脑神经元接收的图像光亮度和对比度都在迅速地变化，大脑怎样检测瞬间变化的光亮度和对比度还不清楚。我们采用快速呈现的光亮度和对比度刺激，模拟自然视觉条件下图像对比度和光亮度的瞬时变化，研究初级视皮层神经元对这两个图像参数的反应性质及其时间过程。实验证明，神经元对不同对比度反应的时程有明显的对比度依赖性，神经元相对于平均活动水平的反应上升或下降表达了刺激对比度的升高或降低，反应的上升或下降通常在30-60ms达到波峰或波谷,反应过程中神经元反应的峰值幅度与当前对比度变化的幅度呈正相关。这样，视皮层神经元对迅速变化的对比度的变化方向和变化幅度敏感，通过活动依赖的机制，编码了相对于当前视觉环境中平均对比度的瞬时变化，即对比度的增加和下降以及变化的幅度。与对瞬时变化光亮度的反应进行分析比较，表明对比度和光亮度的处理是由不同的机制处理的。这些研究揭示了在自然视觉环境中，处理迅速变化的图像对比度和光亮度，产生物体形状视觉的脑机理，是人类和动物感知和区分自然图像中整个0-1范围对比度的生理基础。请访问我的个人网站>>>

Biography&IntroductionProf.YiWangz:2000:PhD,UniversityofOsaka,Japan;2000-2004:Post-doctor,UniversityofTexas-HoustonMedicalSchool,USA;2004-Present:PrincipalInvestigator,InstituteofBiophysics,ChineseAcademyofSciences,China.Theresearchinthislaboratoryisdirectedtounderstandtheneuralmechanismsunderlyingvisualperceptionandrecognitionforobjects.Weareparticularlyinterestedininvestigatingthecorticalrepresentationofobjectfeatures.Theongoingprojectsareontheneuralcodingforluminance,contrast,form,andmotion,andalsoonthefunctionalorganizationinthevisualcortex.Inthemostsituationsofthenaturalvision,thecontrastandluminanceofimagesreceivedbyneuronsinthebrainarerapidlyvarying.Howdoesthebrainencodethetransientchangesinthecontrastandluminanceremainsunclear.Bypresentingrapidly-varyingcontrastandluminancestimulithatsimulatedthetransientchanges,weexploredtheresponsepropertiesofneuronsintheprimaryvisualcortex.Inthetimecourseoftheresponses,aneuronincreaseditsactivityrelativetothemeanexcitatorylevelasthestimuluscontrastwaslargerthantheaveragedcontrastinthesetofcontrasts,whereasdecreaseditsactivityasthecontrastwassmallerthantheaveragedcontrast,thatis,thepositivesignalrelativetothemeanactivitylevelintheneuronalresponsescorrespondedtotheincrementintensityinstimuluscontrastandthenegativeonecorrespondedtothedecrementintensity.Generallyneuronalresponsewentuptothepeakordowntothevalleyat30to60msafterstimulusonset.Therelativerisingorfallingmagnitudesoftheresponsesatthepeakorvalleywereproportionallycorrelatedtothechangemagnitudesofstimuluscontrastincrementordecrementrelativetotheaveragedcontrast.Thecorticalneuronsthusrepresentboththesignsandmagnitudesofthetransientcontrastchangesrelativetotheprevailingcontrastinthecurrentvisualenvironmentbyactivity-dependentmechanisms.Wealsocomparedtheresponsesofneuronstothetransientluminancechangeswiththosetocontrastchanges,suggestingthatthemechanismstoprocessthecontrastandluminanceareindependent.Theseresultsshowinsightintotheunderlyingneuralprocessesresponsiblefortheabilitytodetectanddiscriminatecontrastandluminancethatdefinetheperceptualobjectsinthenaturalvision.VisitmyGroupPageHere>>>

SelectedPublicationsYiWang,YoupingXiaoandDanielJ.Felleman.V2ThinStripesContainSpatiallyOrganizedRepresentationsofAchromaticLuminanceChange.CEREBRALCORTEX..2007,17:116-129(CoverPicture).XiaoY,WangY&FellemanDJ.AspatiallyorganizedrepresentationofcolorinmacaqueareaV2.Nature421:535-539(2003)(Commentstothispaper:ConwayB.Colourvision:acluetohueinV2.CURRENTBIOLOGY13:R308-R310(2003)).WangY,FujitaI,TamuraH&MurayamaY.ContributionofGABAergicinhibitiontoreceptivefieldstructuresofmonkeyinferiortemporalneurons.CEREBRALCORTEX12:62-74(2002).WangY,FujitaI&MurayamaY.Neuronalmechanismsofselectivityforobjectfeaturesrevealedbyblockinginhibitionininferotemporalcortex.NATURENEUROSCIENCE3:807-813(2000)(Commentstothispaper:JagadeeshB.Inhibitionininferotemporalcortex:generatingselectivityforobjectfeatures.NATURENEUROSCIENCE3:749-750(2000)).
联系方式(Contact)：


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010-64888453
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010-64871293
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