how about using arterial spin labeling (ASL) technique?
> From: Carsten Giessing <[log in to unmask]>
> Reply-To: Carsten Giessing <[log in to unmask]>
> Date: Fri, 1 Sep 2006 09:31:30 +0200
> To: <[log in to unmask]>
> Subject: Re: [SPM] long epoch design
>
> Dear Wei Wen:
>
> You can check e.g. the slides from the SPM-course in London:
>
> http://www.fil.ion.ucl.ac.uk/spm/course/slides03/ppt/event.ppt#458,55,Design
> Efficiency
>
> Your design would be very inefficient (the variance in our signal you want to
> measure would be very small due to the filtering characteristics of the HRF).
> The most efficient design is a sinusoidal modulation of neural activity with a
> period of ~24 s (e.g., boxcar with 12 s on/ 12 s off, compare link above and
> Josephs & Henson, 1999). Therefore, I would assume that blobs lighting up in
> statistical analysis would be due to noise.
>
> Best wishes,
> Carsten Giessing
>
> -------- Original-Nachricht --------
> Datum: Fri, 1 Sep 2006 12:59:46 +1000
> Von: "Wen, Wei" <[log in to unmask]>
> An: [log in to unmask]
> Betreff: [SPM] long epoch design
>
>>
>>
>> Hi,
>>
>>
>>
>> Are there any issues there if we have a very long epoch block design?
>>
>>
>>
>> We are planning to have a meditation fMRI study in which the meditator is
>> doing a meditation in the scanner for 6 minutes (meditation condition) and
>> plus several minutes of non-meditation. The signal drifting, the low
>> frequency, etc. What do you people think? Any studies (reports, papers)
>> similar to this that you know of please?
>>
>>
>>
>> Many thanks and regards,
>>
>>
>> Wei Wen
>>
>> UNSW, Australia
>>
>>
>>
>>
>> .
>
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>
>
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