I am analysing a simple finger tapping block design experiment and I am
trying to add additional regressor to my stimulus signal, a signal
recorded and computed using sensory glove capturing the actual finger
tappping movement. This signal is somehow reflecting the movement
performance (both amplitude and temporal characteristics of movement) of
patients during the experiment.
My problem is, that SPM is detrending all the regressors in the design
matrix. I assume it is not what I want (see the picture attached). The
black line shows what I would like to have there, the green one after
My questions are, is there any way of circumventing this without making
changes in code? Or is the detrending of my regressor necessary?
Thank you very much in advance and I wish you a fruitful day.