## marsbar-users

 [Marsbar-users] How are FIR timecourses calculated in MarsBaR? From: Cindy Fan - 2013-08-09 02:15:54 Attachments: Message as HTML ```Dear MarsBaR experts, I would like to ask two questions: I have adopted the instructions in MarsBaR FAQ "How do I extract all FIR timecourses from my design?" to analyze my data, but I would like to know what it means if I change the options to "opt = struct('single', 1)" with no ", 'percent', 1" in it. Does it mean that the output timecourses are not estimates in percent scale and therefore shouldn't be compared between subjects? What exactly does it operate in the function "event_fitted_fir"? Before the estimation, does the FIR model consider the signal intensity from the data that may vary from one data set to another? Thank you very much. Cindy -- Hsin-Ya Fan ```
 Re: [Marsbar-users] How are FIR timecourses calculated in MarsBaR? From: Matthew Brett - 2013-08-10 20:48:18 ```Hi, On Thu, Aug 8, 2013 at 7:15 PM, Cindy Fan wrote: > Dear MarsBaR experts, > > I would like to ask two questions: > > I have adopted the instructions in MarsBaR FAQ "How do I extract all FIR > timecourses from my design?" to analyze my data, but I would like to know > what it means if I change the options to "opt = struct('single', 1)" with no > ", 'percent', 1" in it. Does it mean that the output timecourses are not > estimates in percent scale and therefore shouldn't be compared between > subjects? Well - yes - it means the estimates are not proportional to the baseline. The 'single' option means that you are not estimating the FIR response per second of activity, but over the whole event. > What exactly does it operate in the function "event_fitted_fir"? Before the > estimation, does the FIR model consider the signal intensity from the data > that may vary from one data set to another? I'm not sure I understand you question. The FIR model only has the data from the individual subject and the region you are estimating for. It takes the data, changes the SPM design to have an FIR model for the event of interest, estimates the parameters for that model, scales them by the baseline if you asked it to do that, and returns / plots the results. Best, Matthew ```
 Re: [Marsbar-users] How are FIR timecourses calculated in MarsBaR? From: Cindy Fan - 2013-08-12 02:42:41 Attachments: Message as HTML ```Hi Matthew, Thank you so much for replying. I appreciate your help! 2013/8/11 Matthew Brett > Hi, > > On Thu, Aug 8, 2013 at 7:15 PM, Cindy Fan > wrote: > > Dear MarsBaR experts, > > > > I would like to ask two questions: > > > > I have adopted the instructions in MarsBaR FAQ "How do I extract all FIR > > timecourses from my design?" to analyze my data, but I would like to know > > what it means if I change the options to "opt = struct('single', 1)" > with no > > ", 'percent', 1" in it. Does it mean that the output timecourses are not > > estimates in percent scale and therefore shouldn't be compared between > > subjects? > > Well - yes - it means the estimates are not proportional to the > baseline. The 'single' option means that you are not estimating the > FIR response per second of activity, but over the whole event. > So if I use "opts = struct('single', 1, 'percent', 1);", how would the baseline be defined? by the average activity of the same events or by the average activity of the onset of the same events? If I don't use the 'single' option, what should I enter for estimating FIR response per second (per TR?) of activity? > What exactly does it operate in the function "event_fitted_fir"? Before > the > > estimation, does the FIR model consider the signal intensity from the > data > > that may vary from one data set to another? > > I'm not sure I understand you question. The FIR model only has the > data from the individual subject and the region you are estimating > for. It takes the data, changes the SPM design to have an FIR model > for the event of interest, estimates the parameters for that model, > scales them by the baseline if you asked it to do that, and returns / > plots the results. > > Yes, because if I am estimating the FIR response over the whole event, the data multiplies the inverse matrix of the model (right?), I would like to know how exactly the model is set up and estimated, like does it have a initial guess of signal magnitude (that may affect the estimation) of the data? Best, Cindy > Best, > > Matthew > > > ------------------------------------------------------------------------------ > Get 100% visibility into Java/.NET code with AppDynamics Lite! > It's a free troubleshooting tool designed for production. > Get down to code-level detail for bottlenecks, with <2% overhead. > Download for free and get started troubleshooting in minutes. > http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk > _______________________________________________ > Marsbar-users mailing list > Marsbar-users@... > https://lists.sourceforge.net/lists/listinfo/marsbar-users > -- Hsin-Ya Fan ```