Hi,
All these questions depend on exactly what questions you are wanting
to answer wrt the different models. Maybe it would help further to
have a detailed read of Jeanette's nice stuff at
http://mumford.bol.ucla.edu/perchange_guide.pdf
Cheers.
On 17 Mar 2009, at 23:53, Vishwadeep Ahluwalia wrote:
> Hi Steve,
> Apologies for dragging this question on. Now i'm confused about
> whether to rescale the
> PPheights of the 3 models at all. I got the 3 model waveforms(each
> with a different
> stimulus duration as described in my previous post) from the
> design.mat and rescaled each
> using their respective PPHeights. But i realized that the max and
> min values of the rescaled
> model with the longer stimulus duration is lower than those for the
> shorter stimulus
> duration models, even though all the PPheights are the same. Wouldnt
> this still affect the
> comparibility of PEs of my rescaled models ? Since PE's are
> dependent on PPheights , i was
> wondering if i should be using z-scores instead of PE's to compare
> the three models (i'm
> assuming z-scores arent affected by the PP-Height) or perhaps
> correlation analysis.
> -vish
>
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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
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