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Interpretation of fnirs data

Shiva Pooladvand
Posts: 6
Topic starter
Joined: 6 months ago

Hi all,

My name is Shiva and I am new to fNIRS. Here I have attached an Excel file of a person who has done a task in 5 conditions and each condition lasted 1 minute. I have received this file to interpret and I have some questions:

1- As you can see in the Excel file, the columns are reporting the concentration amounts of O2Hb, HHb and tHb. Can I do any motion corrections or physiological corrections to the data? because I think I need the optical density data to remove artifacts using Homer3.

2- When I plotted the column of time with for example the first column of O2Hb (no matter which condition was), I did not see a smooth graph and it was full of oscillations. Is it normal?

3- Would you please explain why the data includes negative concentration amounts? 

I really appreciate your help and any other advice to assist me in interpreting my data. I want to understand the difference between the 5 conditions considering the baseline.


Kind regards,


1 Reply
Binal Brahmbhatt
Posts: 8
Joined: 2 months ago

Hi Shiva,

I am not sure what is the sampling frequency. But looking from the data looks like detrending  and baseline correction would help moving forward. Have a look at the fft , for presence of  physiological effects.

Hope that helps!