No - BOLD fMRI works in arbitrary units. 10,000 is an arbitrary
number that feat uses to scale the data.
Typically, people will convert their effect sizes into %signal change.
T
On 18 Feb 2010, at 01:37, William Sohn wrote:
> Dear FSL community,
>
> I was wondering what the values of the BOLD signal extracted when
> using
> fslmeants means.
>
> I know BOLD signal is the ratio of oxygenated over deoxygenated
> hemoglobin,
> but I was wondering what the actual numerical value means. For
> example,
> when we use fslmeants to extract timeseries, we get values around
> 10,000.
> Are there units? And is there a method to interpret these values?
>
>
> Thank You,
>
>
>
> William Sohn
>
|