First, slices don't have regressors, so I'm not quite sure what you
are trying to do. Secondly, if you set a slice to 0, then its removes
that slice from the entire analysis because it will be excluded from
the mask.
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
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On Mon, May 13, 2013 at 4:54 PM, Kim, Robert <[log in to unmask]> wrote:
> Dr. McLaren,
>
> Thank you for the quick reply.
> I plan to set the slices and their regressors to 0. Sorry for the confusion.
>
> Thank you,
>
> Robert
> ________________________________________
> From: SPM (Statistical Parametric Mapping) [[log in to unmask]] on behalf of MCLAREN, Donald [[log in to unmask]]
> Sent: Monday, May 13, 2013 4:48 PM
> To: [log in to unmask]
> Subject: Re: [SPM] Removing Noisy Slices
>
> Do you mean slices or did you mean volumes?
>
> If you meant volumes, this will cause issues with the convolution of
> the HRF function. The preferred approach is to add 1 regressor for
> each volume you want to remove. Each regressor will contain all 0s
> except for the volume that is bad. This approach effectively removes
> the volume from the analysis. It would be difficult to form the design
> matrix and then filter the volumes out due to the number of references
> to row numbers and matrix sizes.
>
> If you meant slices, then we'd need more information about what you
> are doing by removing them (e.g. shifting the remaining slices or
> setting the slice to 0.
>
> 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 Mon, May 13, 2013 at 4:35 PM, Robert Kim <[log in to unmask]> wrote:
>> Dear SPM users,
>>
>> I have a simple MATLAB script that computes motion artifacts and framewise displacement from fMRI image slices (.swm files). I plan to identify noisy slices using my script and remove them along with their corresponding regressors manually from my design matrix before performing SPM GLM analysis. Is this reasonable?
>>
>> Thanks in advance,
>>
>> Robert
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