Hi -You can certainly have a negative BOLD response to an event, relative to rest. You need to give more details for us to give more specific insight into the effects.BestEugeneOn 2 August 2017 at 23:02, Aaron Ben Mansel <[log in to unmask]> wrote:Hey Kristian,Thanks for the reply. That's entirely possible. I will need to double check the scripts. What exactly would a negative percent signal change mean?Thanks,BenOn Wed, Aug 2, 2017 at 8:30 PM, Kristian Loewe <[log in to unmask]> wrote:Hi Ben,
Could it be that your time series are being standardized or transformed to percent signal change at some point in your analysis?
On 02.08.2017 20:13, Ben Mansel wrote:
This isn't related to FSL - but I am desperate and thought some of the members here would be able to assist.
I have ran analysis on my functional MRI data using a script provided by somebody else. Problem is, I am not entirely sure what the output is.
The numbers I have for the ROIs should be representing 'Response Magnitude'. However, there are some negative numbers. I was under the impression that a negative magnitude doesn't exist, and I am confused as to how this should be interpreted.
Any help would be seriously appreciated.