[Solved] Clarification hypothesis
Hi FRESH team,
I have a question regarding the hypotheses for the motor data set. What is meant by contralateral here:
"2. Left AND right hand finger tapping of 2 sec duration, conditions combined, evokes a response in the contralateral primary motor cortex."
Same question for hypotheses 3. and 4. Does this mean contralateral to the LEFT hand?
@franzi, i.e. to say: Is the response ,overall, -i.e. considering both left and right-hand finger tapping conditions- significant on the contralateral side. Contralateral side means different for each task i.e. for left-hand finger tapping, a brain activation on the right hemisphere, and for right-hand finger tapping, a brain activation on the left hemisphere. Does that answer your question?
Thanks for reaching out! I am hoping that I will not bias you re your choice of statistical test you will apply but I believe this would be the easiest way to explain it: e.g. for the hypothesis of 2 and 3 sec duration, conditions combined, think of it as a pool of all trials combined. However for the 2 and 3 sec left hand conditions, the response is coming from the right hemisphere (either a channel or an ROI or a bunch of voxels you have chosen), and similarly for the right hand, you have the response from the left hemisphere. Eventually you will have a pool of trials for all conditions, a hemodynamic response on the contralateral side for each of these trials, and you need to find, given all trials, whether this response is higher than baseline. Please let me know if this clarifies things for you.
This has indeed helped us with interpreting the hypotheses. Thanks a lot for your detailed response!