Hi,
On 19 Feb 2009, at 01:38, Yuzheng HU wrote:
> Dear Prof. Smith
>
> Thank you. I have still have two questions.
>
>
>>> I intend to do unpaired two-sample t-test with IQ scores as confound
>>> regressor. I designed events and contrasts like this:
>>> ------------------------------------------------
>>> EVs
>>> Number of main EVs 3
>>> Number of addition, voxel-dependent EVs 0
>>> Group EV1(group_A) EV2(group_B) EV3(demeaned_IQ)
>>> 1 1 0 -9.7
>>> 1 1 0 1.2
>>> : : : :
>>> 2 0 1 12.2
>>> 2 0 1 -10.0
>>>
>>> Contrasts
>>> Contrast 2 F-tests 0
>>> for_group_A>group_B 1 -1 0
>>> for_group_B>group_A -1 1 0
>>>
>
> Q1: If I add a contrast '0 0 1' to my desin.con, can I obtain the
> result
> positively correlated with IQ scores by this contrast?
Yes.
>
>
>>> Must I use option in randomise? May I use --T2?
>> -x gives you voxelwise inference but you probably don't want that -
>> you probably just want TFCE, using the --T2 option.
>
> Q2. When searching the archives, it was suggested that -x should be
> used in
> TBSS randomise for two-sample t-test with confoud regressor. While --
> T2
> option as well could be used in the current randomise version
> ( randomise
> V2.1) even for two-sample t-test with confound regressor. Right? I
> am sorry
> for my vague qusetion in previous email.
>
Sorry - that's an out-of-date option - we no longer have a separate
option for confound matrices. The -x option is for voxelwise stats,
which you don't need if you're using TFCE.
Cheers.
> Thanks again.
>
>
>>> Thanks a lot.
>>>
>>> sincerely, Yuzheng
>>>
>>> ========================
>>> Biox-lab, Zhejiang Univ. China
>>> ========================
>>>
>>
>>
>> --------------------------------------------------------------------------
> -
>> 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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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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