Hi Russ,
Thank you very much! We don't have multiple repetitions of each face
(only once)in each run. Do you mean that it makes no sense to calculate
the psc for each face stimulus?
Many thanks!
On Wed, 23 May 2007 08:46:17 -0700, Russell Poldrack <[log in to unmask]>
wrote:
>xiaoyun,
>do you have multiple repetitions of each face? if not, then it will
>be difficult to get a stable estimate of the response to a single
>item. if the items are repeated then you have to worry about
>repetition effects.
>cheers
>russ
>
>On May 23, 2007, at 8:43 AM, Xiaoyun Liang wrote:
>
>> Hi,
>> I wonder if I can obtain the percent signal change with respect
>> to each
>> stimulus of each condition (not average of each condition) in
>> randomized
>> event-related fMRI,e.g.,if we have four face category, with ten
>> faces each
>> category,and I want to calculate the percent signal change with
>> respect to
>> each face of the same face category instead of face category.
>> Thanks a lot!
>>
>>
>>
>>
>> Xiaoyun
>>
>
>---
>Russell A. Poldrack, Ph.d.
>Associate Professor
>Wendell Jeffrey and Bernice Wenzel Term Chair in Behavioral Neuroscience
>UCLA Department of Psychology
>Franz Hall, Box 951563
>Los Angeles, CA 90095-1563
>
>phone: 310-794-1224
>fax: 310-206-5895
>email: [log in to unmask]
>web: www.poldracklab.org
>
>
>
>
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