Esther,
Yes, that's exactly what I meant. Good luck!
Jonathan
On Wed, Mar 25, 2009 at 3:13 PM, Esther Fujiwara <[log in to unmask]> wrote:
> Thanks very much for your responses everyone! This does make a lot of sense.
> Just to verify, I would have 9 conditions (blocks A,B,C, events 1,2) set up
> like this:
>
> blocks (duration 30)
> A
> B
> C
>
> events (duration 0)
> A1
> A2
> B1
> B2
> C1
> C2
>
> which equals 9 conditions (i.e., not A1, A2, B1, etc. with 30 duration).
>
> Thanks for verifying!
>
> Esther
>
>
> Jonathan Peelle wrote:
>>
>> Hi Esther
>>
>> A quick response to your last question:
>>
>>> Quickly with regard to the conditions: I want to use a factorial design,
>>> so
>>> I believe I need to set up my conditions as indicated (6 total).
>>>
>>> The way I am doing this right now is as follows: I include the block
>>> onsets
>>> together with event onsets in the same condition file, i.e., if one run
>>> has
>>> two blocks and five events per block, the input would look like this:
>>>
>>> onsets:
>>> 14 16 21 22 24 25 136 137 145 149 150 158
>>> duration:
>>> 30 0 0 0 0 0 30 0 0 0 0 0
>>
>> The problem with this approach is that by including both the sustained
>> and transient activity in the same condition, you make it impossible
>> to separate the two effects. I think what you want, as Donald
>> suggested, is 9 conditions:
>>
>> block 1 (duration of 30 sec)
>> A in block 1 (duration of 0)
>> B in block 1
>>
>> block 2 (duration of 30 sec)
>> A in block 2
>> B in block 2
>>
>> etc.
>>
>> This should let you test for all of the main effects and interactions
>> in your design.
>>
>> I wouldn't think you would need to worry about different shapes of
>> HRF. If there is indeed sustained activity during these blocks, then
>> I would think that the standard SPM convolution with the HRF would
>> reflect this. If you did want to use different basis sets, I don't
>> think there is a way to do this in the GUI; you would probably have to
>> write some code to do this.
>>
>> Hope this helps,
>>
>> Jonathan
>>
>
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