Dear Prof. Smith
Thank you very much. I've got it.
On Thu, 19 Feb 2009 09:17:12 +0000, Steve Smith <[log in to unmask]>
wrote:
>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Sorry - that's an out-of-date option - we no longer have a separate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
>>> -----------------------------------------------------------------------
---
>> -
>>
>
>
>--------------------------------------------------------------------------
-
>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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