Hi, I am using Homer3 and have some questions about the block average function and exporting HRF mean.
First, which condition is given to calculate the block average?
Second, how does the block average function normalize the baseline? Do you have a suggestive time range for baseline normalization?
Also, what information does the "exporting subjects HRF mean" function give? More specifically, I am not sure about time range setting whether it should have a baseline period as block average or not ( That is, is it okay to set the min time to '0', which is the exact event start period?)
Thank you in advance.
Hi Kanghee,
Please see my responses below:
"First, which condition is given to calculate the block average?"
Block average is calculated for each condition.
"Second, how does the block average function normalize the baseline? Do you have a suggestive time range for baseline normalization?"
It subtracts the baseline range you have provided to the function in the edit options menu. E.g., if you entered -2 15 to the trange, it will take the mean from -2 to 0 (before stim onset) and subtract it from the whole HRF.
"Also, what information does the "exporting subjects HRF mean" function give? More specifically, I am not sure about time range setting whether it should have a baseline period as block average or not ( That is, is it okay to set the min time to '0', which is the exact event start period?)"
Exporting HRF mean option allows you to choose a time range (e.g. around peak) to calculate the mean HRF values and export.
Meryem
Hi, just to pick up here. If I wanted the mean HRF output for stimulus onset (0) to 30 seconds would I put '0' and '30' i.e. has the baseline deduction already been factored in at the previous processing level?
Yes.