Predefined Types
My major research interest is Independent Component Analysis (ICA): methodology and applications.
(我主要的研究兴趣为ICA算法和应用)
If any questions regarding with ICA, please feel free to post here and I will try my best to solve them.
(因此，如果各位有任何独立成分分析ICA相关问题，请在这里提出，我每天会尽量回答并解决)
And I will post some helpful information about ICA each day if I have time.
(我也会贴出一些ICA相关知识在这里，尽量做到每天)
期待张师兄贴出一些关于ica的知识
choice of preprocessed images for ICA
Yes, some papers used
Yes, some papers used smoothed data for ICA, while some did use the detrend or filtered data for ICA.
No systematical comparision between the two preprocessing methods in ICA studies.
I recommand the first one.
Re: Questions about ICA plz posting here (独立成分分析相关问题我在这里做解答)
I have a question regarding ICA.
I'm using the fastICA algorithm and I have this problem. My two dependent variables, say X1 and X2 are mixtures of one common non gaussian variable T and two gaussian error terms. My algorithm is able to recover the signal T (I did a lot of simulations), but I want to prove it theoretically. Do you have any suggestion?
My model can be written as:
X1=T+E1
X2=T+E2
where T is non gaussian, E1 and E2 are gaussian and the three variables (T, E1 and E2) are independent.
Thank you in advance for your help
Re: Questions about ICA plz posting here (独立成分分析相关问题我在这里做解答)
As far as I know, fastICA model is not like X1 = T+E1. So I assumed that X1, X2 are the variables you got from fastICA, and that you intended to further decompose those variables into mixture of a nongaussian and a gaussian additive variable. Did I understand correctly?
The general rule is if E1 and E2 are two independent variables with Gaussian distribution, they can not be separated by using ICA.
Han
Re: Questions about ICA plz posting here (独立成分分析相关问题我在这里做解答)
I have a question about ICA. Is it reasonable to perform ICA in follow-up study, since a subject's data at baseline and follow-up time are interelated each other。
Best Wish！
Re: Questions about ICA plz posting here (独立成分分析相关问题我在这里做解答)
我在使用mica的时候，在成分挑选的时候，gui view界面中点击sort components，并且选择空间相关并加载了需要的DMN网络模板，点击ok之后，软件没有任何反应，
问题1：恳请张寒老师指导一下，mica中sort components的使用。
问题2：identify components在使用默认的设置，全部勾选，点击ok，matlaB就会报错，请问identify components的作用以及他的使用方法。
Idendentify components
??? Undefined function or variable 'dim'.
Error in ==> view_gui>ButtIdenComp_Callback at 898
[ICNOs]=nic_removeNoiseComponent(compNum,dim,outPrefix,threshold,zipFilePath,a);
Error in ==> gui_mainfcn at 96
feval(varargin{:});
Error in ==> view_gui at 30
gui_mainfcn(gui_State, varargin{:});
??? Error while evaluating uicontrol Callback
Re: Questions about ICA plz posting here (独立成分分析相关问题我在这里做解答)
望大家帮忙回复一下
关于ICA挑选成分后进行 one sample T test时，mask选用问题的疑惑
张老师：
老师好！我是最近才开始学习使用gift做ICA分析。有个疑惑想请教下
在对挑选好的成分做 one sample T test时，有个mask选用的问题，不知道如何选用为好。 因为用spm做second level 统计时，有一个explicit mask选项； 用dpabi做one sample T test时也有个mask选项；所以我的困惑在这里该用默认的mask呢（不选代表默认的）？还是用在这个成分内的mask，如DMN mask呢？
两个都试了下。发现如果不选，使用默认的mask，结果发现，激活脑区非常多，好多脑区根本不是这个网络成分的内，甚至都有小脑上的激活。有个cluster团块非常大，有将近一万个体素。
DPARSFA Standard Preprocessing for ICA
Hello.
I am new to ICA. Previously I have worked with functional connectivity and DPARSFA.
My question is: how shlould I change the proprocessing when we want to made ICA?.
I read that no filter and no detrend should be there. I hope I can copy the DPARSFA window we used on our previous functional connectivity study.
Thank you very much for your help.
Sergio Elías Hernández
Universidad de La Laguna, Spain
DPARSFA Standard Preprocessing for ICA
Hello.
I am new to ICA. Previously I have worked with functional connectivity and DPARSFA.
My question is: how shlould I change the proprocessing when we want to made ICA?.
I read that no filter and no detrend should be there. I hope I can copy the DPARSFA window we used on our previous functional connectivity study.
Thank you very much for your help.
Sergio Elías Hernández
Universidad de La Laguna, Spain