[Mne_analysis] Comparing conditions

[Padraig Kitterick]

Because you are distorting the dipolar topographies when you do a 
subtraction at the sensor level. The resulting data is likely contain 
field patterns which do not relate to the leadfields of the actual 
sources that gave rise to the data. Thus, any source reconstruction 
which relies on lead field models, i.e. minimum norm, will give spurious 
results.

-Padraig

Yury Petrov wrote:
> Why not first subtract one average response from the other and then  
> localize?
>
> On Sep 29, 2008, at Sep 29, 2008 | 6:28 AM, Alex Clarke wrote:
>
>   
>> Hi there,
>>
>> I have a question regarding how best to statistically compare two  
>> conditions. So far I have only being comparing between 2 conditions  
>> using ROIs and comparing current estimates over time. However, I'd  
>> also like to see the difference between two conditions across the  
>> whole brain. I was wondering what the best approach to this was  
>> (Ideally ending up with a dSPM map of condition1 - conditon2).
>>
>> Any help on this would be appreciated
>>
>>
>> Thanks,
>>
>> Alex Clarke
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>
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>   


-- 
Pádraig Kitterick
Graduate Student
Department of Psychology
University of York
Heslington
York YO10 5DD
UK

Tel: +44 (0) 1904 43 2883
Email: p.kitterick at psych.york.ac.uk


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