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Dear, Thank you for your answer. It helps a lot. I have one more question. Then, I am wondering when you scale (normalize) the data, is it before or after the multisession GLM analysis? Based on your explanation, I understood that you concatenate the data of all sessions, then scale (normalize) the concatenated data, and then conducted the multisession glm. Am I correct? Thanks ahead. Woogul Lee On Fri, Jan 14, 2011 at 4:55 PM, Michael T Rubens <[log in to unmask]>wrote: > multisession glm means running all of your sessions in one model. I don't > know how to do it in the gui because i have all my analysis scripted, but i > can't imagine its too hard to figure out. > > while one could argue that their maybe scan specific baseline activity > across sessions, the 'constant' regressor theoretically should absorb the > noise, which can facilitate comparisons across sessions. > > cheers, > michael > > > On Thu, Jan 13, 2011 at 11:31 PM, Woogul Lee <[log in to unmask]> wrote: > >> Dear, >> >> Thank you for your answer. >> I think I need to explain my study design more specifically. >> We have three runs. >> In the first run, there were trials of the baseline condition only. >> In the second run, there were trials of the "A" condition only. >> In the third run, there were trials of the "B" condition only. >> Now, we tried to compare the activation differences between A and >> baseline, between B and baseline, or between A and B. >> Are there ways that we can do that? >> >> You mentioned about the multisession glm. >> In this situation, we are wondering whether the standardized beta >> coefficient of the A condition, that of the B condition, and that of >> baseline are comparable. >> As beta coefficient of each condition was calculated based on the mean >> values of each target run (first run for baseline, second run for A >> condition, third run for B condition), we think the standardized beta values >> are not comparable. >> >> Could you let me know whether we still need to consider this problem in >> the multisession glm that you suggested, what the multisession glm is >> exactly, and how we conduct it with SPM? >> Thanks. >> >> Woogul Lee >> >> On Fri, Jan 14, 2011 at 2:50 PM, Michael T Rubens <[log in to unmask]>wrote: >> >>> not sure I fully understand you're problem, i fail to see an issue. what >>> is the nature of your conditions? >>> >>> Just run a multisession glm, which will pop out 3 betas, and then just >>> make your contrasts. >>> >>> Cheers, >>> M >>> >>> >>> On Thu, Jan 13, 2011 at 9:16 PM, Woogul Lee <[log in to unmask]> wrote: >>> >>>> Dear all >>>> >>>> >>>> >>>> I am stuck in the design problem so I sincerely hope you to help me. >>>> >>>> >>>> >>>> Basically, our design is block design consisting of three DIFFERENT >>>> runs. The problem is that each run has only one condition (sigh…) so I >>>> cannot compare A condition with B or C condition directly. Unfortunately, I >>>> realized the fact very lately after conducting the experiment. >>>> >>>> >>>> >>>> Is there any way I can compare those different conditions >>>> statistically?? >>>> >>>> >>>> >>>> If you have any idea, please, help me. >>>> >>>> >>>> >>>> >>>> >>>> Best regards >>>> >>>> >>>> >>>> Woogul Lee >>>> >>> >>> >>> >>> -- >>> Research Associate >>> Gazzaley Lab >>> Department of Neurology >>> University of California, San Francisco >>> >> >> > > > -- > Research Associate > Gazzaley Lab > Department of Neurology > University of California, San Francisco >