[pymvpa] Why to standardize (z-score) a time course?

Yaroslav Halchenko debian at onerussian.com
Sun Aug 1 02:55:12 UTC 2010

On Sat, 31 Jul 2010, Vadim Axel wrote:
>    To be on the safe side, what is the equation for " z-scoring against
>    baseline" you mentioned? I guess that you subtract the baseline
>    condition instead of the average. But how you calculate the std?
the same -- std within the baseline condition. so effectively you get
z-scores of possible effects

>    Do you mind name some "reasonable scaling approaches"? In one of your
>    papers you also tested " scaled percentage change relative to
>    baseline".
could be one if you don't believe in statistics but in some hypothetical
model of HRF where the effect should be proportional to the value of
baseline condition...  or may be just scale in respect to medium and one
of the moments,,, or just min/max to be within [-1,1] (quite unstable
imho), or ... ? ;)

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