This is the 6th post of the series: Handy programs to visualize NIRS data
When we do an experiment, we often repeat an event (or block) for a few times. For example, in a typical finger tapping task, we ask the participants to do a finger tapping for 20s, then rest for 20s, then repeat the whole tap-rest paradigm for 10 time.
After we extract the NIRS time courses, we often need to know the average of the signal over all repetitions of the event. In the finger tapping experiment, we want to know the average signal across 10 blocks of finger tapping.
What we need to do is:
- Know the timing of each block (of course!)
- cut the NIRS signal into pieces. The starting points should be a few seconds before the onset timing of the experiment block; and the ending points should be a few seconds after the offset of the experiment block.
- Align the pieces and average
- Also calculate the standard deviation (or error) of the average