第24章生物醫學影像處理BIOMEDICAL IMAGE PROCESSING.pptx
《第24章生物醫學影像處理BIOMEDICAL IMAGE PROCESSING.pptx》由会员分享,可在线阅读,更多相关《第24章生物醫學影像處理BIOMEDICAL IMAGE PROCESSING.pptx(39页珍藏版)》请在得力文库 - 分享文档赚钱的网站上搜索。
1、Biological Systems and Electronics第第六六章章 Chapter 6計算神經科學Computational Neuroscience1Biological Systems and ElectronicsComputational Modeling in NeurosciencenLevels of detailsBiophysicsCircuit modelsSystemsnApproaches:Descriptive 描述性=the“what”Mechanistic 機制性=the“how”Interpretive 詮釋性=the“why”2Biologica
2、l Systems and ElectronicsDescriptive vs.Mechanistic ModelsnWhat vs.How:The main purpose of descriptive modeling is not to explain but to describe.nBelow are example of tools:Fourier transformIndependent component analysisProbabilistic modelingThe main purpose of mechanistic modeling is explain how p
3、henomena happenne.g.,generation of action potential(動作電位)can be explained by principles of statistical mechanics and Kirchhoffs laws3Biological Systems and ElectronicsOutlinenDescriptive modelingSpectral analysis of EEGProbabilistic approachesnVisual tuning curve of monkeynCercal system of crickets
4、nMechanistic approachGeneration of action potentialsnTopics for further studies4Biological Systems and Electronicsanalysis of sleep Electroencephalogram(EEG)5林志峰(2011):台大應力所碩士論文Biological Systems and ElectronicsPower variation with time,computed via short-time Fourier transform6發現:失智症老人之alpha-theta
5、相似度較非失智症者高(Lin et al.,2011)Biological Systems and Electronicsthe probabilistic approachNeural EncodingStimulus 刺激Response 反應decoding7Biological Systems and ElectronicsMeasuring the firing rateDayan&Abbott,Fig.1.48Biological Systems and ElectronicsTuning curve:firing rate as stimulus condition varies
6、9Biological Systems and ElectronicsSpike-train statistics10Biological Systems and ElectronicsStudies on optimal decodingnGoal:to assess amount of information encoded in spike-train statisticsPs:the probability of stimulus s being presented,often called the prior probabilityPr|s:the conditional proba
7、bility of evoking response r,given that s is presented(the process of encoding)Ps|r:the conditional probability of s being presented given that r was recorded(the process of decoding)11Biological Systems and ElectronicsExample:Single neuron response to visual stimulus12Biological Systems and Electro
8、nicsBehavior vs.neuronal decoding13Biological Systems and ElectronicsReceiver operating curves(ROC)1-specificitySensitivity14Biological Systems and ElectronicsStimuli:Discrete vs.ContinuousnSo it is possible that single neuron responses can tell us about discrete properties of certain stimuli nHow a
9、bout continuous variables?Population decoding15Biological Systems and ElectronicsPopulation decoding by crickets cercal system(cerci=尾毛)16http:/www.biol.sc.edu/vogt/courses/neuro/neurolabs.htmlWhat do the cerci do?Biological Systems and ElectronicsVector-sum decoding17Biological Systems and Electron
10、icsSummary of descriptive modelingnWith mathematical analysis,we can interpret experimental findings on neural encoding and decoding.But how about the physiological basis?18Biological Systems and ElectronicsnMembrane capacitance and resistancenEquilibrium and reversal potentialsnSingle compartment m
11、odelsnVoltage-dependent conductancesnHodgkin-Huxley modelMechanistic approaches:“One cell at a time”19Biological Systems and ElectronicsMembrane capacitance and resistance20Typical values:rm=1 M ohm mm2or 25 pS per channelCm=10 nF/mm2(neuron surface area =0.01 to 0.1 mm2)Biological Systems and Elect
12、ronics細胞間之訊息傳遞機制 (Intercellular Communications:Signal Transduction Mechanisms)1.神經細胞的動作電位(The Action Potential)(a)膜電導之變化 Change in membrane conductance(b)膜電位的變化 Change in membrane potential21Biological Systems and ElectronicsNernst Equation and Reversal Potential 細胞在靜止時,膜內有較多負電荷而膜外有較多正電荷,因此形成負靜止電位(r
13、esting potential)How come?Nernst Equation:EX=ln =0.058 log10 XoutsideXinsideRTzFXoutsideXinsideR(gas constant)=1.987 cal/mol-degreeT=absolute temperatureF(Faraday constant)=23,062 cal/V-molz=valenceXoutside=concentration of X outside the cellXinside =concentration of X inside the cell;22Biological S
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 第24章生物醫學影像處理BIOMEDICAL IMAGE PROCESSING 24 生物 影像 BIOMEDICAL
限制150内