Hi,
From the FEAT manual/webpage/bubble-help:
For even finer control over the input waveform, choose Custom (3
column format). In this case the custom file consists of triplets of
numbers; you can have any number of triplets. Each triplet describes a
short period of time and the value of the model during that time. The
first number in each triplet is the onset (in seconds) of the period,
the second number is the duration (in seconds) of the period, and the
third number is the value of the input during that period. The same
comments as above apply, about whether these numbers are 0s and 1s, or
vary continuously. The start of the first non-deleted volume
correpsonds to t=0.
The last sentence I believe answers your question - it is referring to
time in seconds.
All the best,
Mark
On 6 Jul 2010, at 15:59, Modestino, Edward J *HS wrote:
> Hello,
> Before entering FEAT, I create a list of the onsets of each event/
> epoch volume and the duration of the event/epoch. From this, I
> convert it to time, based in the TR, to a format that can be easily
> imported and used in the FEAT stats tab which can be selected under
> Filename. What I realized is that I was using the volume number as
> onsets before converting to time. As volumes need to be zero
> indexed to time, that is, before volume one is completely collected
> in a TR of 2 seconds/28 slices, one must start with a zero index of
> the volume. So, in essence, by specifying the volume number before
> converting to time, I was approximately one TR (2 seconds) off. So,
> before converting to time, I need to -1 volume for each onset to
> make this more accurate. I was emailing you this to make sure.
> Thanks,
> Ed Modestino
>
>
> Edward Justin Modestino, Ph.D.
> Postdoctoral Research Associate
> Ray Westphal Neuroimaging Laboratory
> Division of Perceptual Studies
> Department of Psychiatry and Neurobehavioral Sciences
> University of Virginia
> Email: [log in to unmask]
>
> From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On
> Behalf Of Stephen Smith
> Sent: Monday, July 05, 2010 4:09 AM
> To: [log in to unmask]
> Subject: Re: [FSL] Zero-indexed?
>
> Hi - need a more specific question - which options (in FEAT I guess)
> are you asking about?
> Cheers.
>
>
> On 2 Jul 2010, at 14:20, Modestino, Edward J *HS wrote:
>
>
> Hello,
> I have a simple question. Are volumes zero-indexed for the input of
> events in a design?
> Thank you,
> Ed
>
> Edward Justin Modestino, Ph.D.
> Postdoctoral Research Associate
> Ray Westphal Neuroimaging Laboratory
> Division of Perceptual Studies
> Department of Psychiatry and Neurobehavioral Sciences
> University of Virginia
> Email: [log in to unmask]
>
>
>
> ---------------------------------------------------------------------------
> Stephen M. Smith, Professor of Biomedical Engineering
> Associate Director, Oxford University FMRIB Centre
>
> FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
> +44 (0) 1865 222726 (fax 222717)
> [log in to unmask] http://www.fmrib.ox.ac.uk/~steve
> ---------------------------------------------------------------------------
>
>
>
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