Sorry that I keep on asking questions but I want to know if using a model
can significantly increase the chance of getting a significant response.
As far as I see for the positive peak, when I use a model (e.g. gamma
model or spmhrf), I see a more significant response compared to when I use
the FIR model. Is it correct? If true, then the same might be correct for
the negative peak.
P.S.: To be more clear, I am talking about the response maps relative to
the baseline.
On Apr 10, 2013 6:46 PM, "Douglas N Greve" <gr...@nmr.mgh.harvard.edu>
wrote:
>
> yes, that is what you want. The only other way that comes to mind is to
> model each event type as two event types one delayed relative to the other.
> Then model the responseto each as a gamma. If the delay is right, then the
> first gamma should model the main positive response and the second gamma
> will model the negative response. both will be independent from the other.
>
> doug
>
> On 04/10/2013 05:00 PM, sha...@nmr.mgh.harvard.edu wrote:
>
>> I think I figured it out but I want to double check. I am generating
>> group-average map for my subjects using isxconcat-sess command which
>> generates ces maps for each time frame. I think these maps are what I
>> wanted. Right?
>> If you still have other solutions that you think may generate more
>> reliable results, I am eager to know. For instance, is there anyway to
>> fit a model as we do for spmhrf or fslhrf, but just for the negative
>> peak?
>>
>> Regards
>>
>> That's the problem Doug. I have already generated the FIR model but how
>>> can
>>> I show the sig MAP for one "particulat time point". What are the other
>>> ways?
>>>
>>>
>>> On Wed, Apr 10, 2013 at 4:05 PM, Douglas N Greve
>>> <gr...@nmr.mgh.harvard.edu>**wrote:
>>>
>>> Hi Shahin, there are several ways that you could do it. The one that
>>>> immediately comes to mind is to use an FIR and then test for a
>>>> difference
>>>> at a particular post stimulus time point.
>>>> doug
>>>>
>>>>
>>>>
>>>>
>>>> On 04/10/2013 03:54 PM, SHAHIN NASR wrote:
>>>>
>>>> Hi,
>>>>> I want to generate a map to show the significant difference
>>>>> between
>>>>> HRF undershoot (negative peak of activity) between two conditions
>>>>> independent from the positive peak. Is there anyway, to generate this
>>>>> map?
>>>>>
>>>>> P.S.: Please note that I need a map and not a time course graph.
>>>>>
>>>>>
>>>>> --
>>>>> Shahin Nasr
>>>>>
>>>>> PhD in Cognitive Neuroscience
>>>>> Martinos Imaging Center, MGH
>>>>> Harvard Medical School
>>>>>
>>>>> --
>>>> Douglas N. Greve, Ph.D.
>>>> MGH-NMR Center
>>>> gr...@nmr.mgh.harvard.edu
>>>> Phone Number: 617-724-2358
>>>> Fax: 617-726-7422
>>>>
>>>> Bugs:
>>>> surfer.nmr.mgh.harvard.edu/****fswiki/BugReporting<http://surfer.nmr.mgh.harvard.edu/**fswiki/BugReporting>
>>>> <http://**surfer.nmr.mgh.harvard.edu/**fswiki/BugReporting<http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting>
>>>> >
>>>> FileDrop:
>>>> www.nmr.mgh.harvard.edu/****facility/filedrop/index.html<http://www.nmr.mgh.harvard.edu/**facility/filedrop/index.html>
>>>> <h**ttp://www.nmr.mgh.harvard.edu/**facility/filedrop/index.html<http://www.nmr.mgh.harvard.edu/facility/filedrop/index.html>
>>>> >
>>>> Outgoing: ftp://surfer.nmr.mgh.harvard.***
>>>> *edu/transfer/outgoing/flat/**
>>>> greve/ <ftp://surfer.nmr.mgh.harvard.**edu/transfer/outgoing/flat/**
>>>> greve/ <ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/>
>>>> >
>>>>
>>>>
>>>>
>>>>
>>> --
>>> Shahin Nasr
>>>
>>> PhD in Cognitive Neuroscience
>>> Martinos Imaging Center, MGH
>>> Harvard Medical School
>>>
>>>
>>>
>>> --
>>> Shahin Nasr
>>>
>>> PhD in Cognitive Neuroscience
>>> Martinos Imaging Center, MGH
>>> Harvard Medical School
>>> ______________________________**_________________
>>> Freesurfer mailing list
>>> Freesurfer@nmr.mgh.harvard.edu
>>> https://mail.nmr.mgh.harvard.**edu/mailman/listinfo/**freesurfer<https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer>
>>>
>>
>>
> --
> Douglas N. Greve, Ph.D.
> MGH-NMR Center
> gr...@nmr.mgh.harvard.edu
> Phone Number: 617-724-2358
> Fax: 617-726-7422
>
> Bugs:
> surfer.nmr.mgh.harvard.edu/**fswiki/BugReporting<http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting>
> FileDrop:
> www.nmr.mgh.harvard.edu/**facility/filedrop/index.html<http://www.nmr.mgh.harvard.edu/facility/filedrop/index.html>
> Outgoing: ftp://surfer.nmr.mgh.harvard.**edu/transfer/outgoing/flat/**
> greve/ <ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/>
>
>
>
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
The information in this e-mail is intended only for the person to whom it is
addressed. If you believe this e-mail was sent to you in error and the e-mail
contains patient information, please contact the Partners Compliance HelpLine at
http://www.partners.org/complianceline . If the e-mail was sent to you in error
but does not contain patient information, please contact the sender and properly
dispose of the e-mail.
