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Hi Donald, Thank you very much for your help in this mailing list. I want to discuss with you and others something. So for the previous point, I cannot do it in a rapid jittared event design where most of the trials are represented in ITI of 2 seconds. Am I correct? If can do or cannot, would extracting the beta ( the Y ) when I plot fitted response is more accurate than taking the mean signal from the smoothed volumes ( and not entering them into spm first level analysis ). The point that I would like to make is : Say I have two force conditions where subjects have to apply force to a certain target A and B. In this case, I can choice, like others, two way of designing my GLM : a parametric response where I have one main regressor and another one, two or three ( parametric modulations) for the actual response OR a categorical where I can represent each force with a regressor. We use a rapid event design. The aim is to find how BOLD response and behaves. The Questions that I have are : 1) Taking into acount the variable responses from subjects ( for example instead of targeting to 10 they target to 13 or 15 or 8 and so on, and this varies among trials ) would it be correct if we categorize forces or best if we use a parametric design. 2) We want to plot in x force and in y signals. What is the best way to do this : Would the original idea ( taking mean signal from a ROI in each volume and then plot this ) is correct OR should we stick with a parametric response or categorical design? The main aim is to see how force and BOLD correlates with each other ? I hope this was not confusing Thanks Aser On Wed, Sep 4, 2013 at 3:11 PM, MCLAREN, Donald <[log in to unmask]>wrote: > You'd need a slow event-related design with one trial about every 30 > seconds to isolate the BOLD response to a particular trial. If that is the > case, then you could use the resting state tools to extract the ROI time > series and then divide it up by the trials. > > Best Regards, Donald McLaren > ================= > D.G. McLaren, Ph.D. > Research Fellow, Department of Neurology, Massachusetts General Hospital > and > Harvard Medical School > Postdoctoral Research Fellow, GRECC, Bedford VA > Website: http://www.martinos.org/~mclaren > Office: (773) 406-2464 > ===================== > This e-mail contains CONFIDENTIAL INFORMATION which may contain PROTECTED > HEALTHCARE INFORMATION and may also be LEGALLY PRIVILEGED and which is > intended only for the use of the individual or entity named above. If the > reader of the e-mail is not the intended recipient or the employee or agent > responsible for delivering it to the intended recipient, you are hereby > notified that you are in possession of confidential and privileged > information. Any unauthorized use, disclosure, copying or the taking of any > action in reliance on the contents of this information is strictly > prohibited and may be unlawful. If you have received this e-mail > unintentionally, please immediately notify the sender via telephone at > (773) > 406-2464 or email. > > > On Wed, Sep 4, 2013 at 7:18 AM, A a <[log in to unmask]> wrote: > >> Hi all, >> >> Would it be possible and accurate to extract signals from a ROI in each >> volume? Say in the smoothing step. I am trying to find how signal behaves >> in each volume as I am using a parametric design that requiring subjects to >> response to a motor task. >> So I want to plot in x the different task ( say for example subjects >> response and forces ) that I have and in y the signals from each volume in >> each subject. >> >> Is this correct? if yes how I can do this. >> >> Thanks >> >> Aser >> > >