Could you please help me with the steps to calculate the Inter regional tPAC analysis of the signal with different channel?
The signal(multi-channel Local field potentials) simultaneously recorded from hippocampus and prefrontal cortex.
I am lookforward to get some information. thank you.
@Samiee: can you please help this user?
Sure,
You can find it in “Frequency > Time-resolved Phase-amplitude coupling > inter-regional tPAC”
Using it is very similar to local tPAC (https://neuroimage.usc.edu/brainstorm/Tutorials/TutPac#Time-resolved_PAC_estimation_with_tPAC), the only difference is that you select the region for fp (nesting frequency) and fA (nested frequency), separately.
If you have more than one channel per region, it is recommended to use one seed from the channels in region for fP and all channels in the fA region, which is the first option in the “Inter-regional coupling type” section (because the spatial resolution of slower rhythms is relatively lower).
If you do not have any prior assumption about which region is driving the other one you can run it both ways and compare the results.
Post here if you have any further question,
Good luck,
Soheila
Thanks, Samiee.
I’ll try it your way.
PS：Could you provide any paper indroducing mathematical algorithms about the inter-regional tPAC in this toolbox（brainstorm）？
Thank you for your reply.
Your suggestion:
Firstly,choose one channel from seed region(multi-channels);
Second, reconstruct of the matrix(n*m),row 1th is seed channel(fP),the other are the fA region channels.
So,in the Pipline editor ,
SEED:Row name or index:1 ?
Sensors/Sources to be investigated:
Row names or indices (empty =all):........?
Thanks
Rock
Sure,
This is the paper for tPAC in general (similar method with fA or fP coming from the second region was applied in inter-regional PAC)
Samiee, Soheila, and Sylvain Baillet. "Time-resolved phase-amplitude coupling in neural oscillations." NeuroImage 159 (2017): 270-279.
https://www.sciencedirect.com/science/article/pii/S1053811917306195
Hi Rock,
Let’s assume you want to investigate inter-regional phase-amplitude coupling between prefrontal cortex and hippocampus, and you have 8 recording channels in prefrontal cortex (1:8) and 8 in the hippocampus (9:16).
My suggestion was that if you are assessing for example how much phase of slow oscillations in hippocampus drive the power of faster rhythms in prefrontal cortex, enter one of eight electrodes from fP region as seed (e.g. 9), and enter all of them from fA region as sources (1:8). After computing irtPAC, you will have a time resolved map of coupling time vs fA with color showing the strength of coupling for each of (1:8) electrodes separately.
You can average them together using: “Run> Frequency > time-resolved PAC > Basic analysis > mean over sources”, or extract the comodulogram (fP vs fA map) using “Run > Frequency > time-resolved PAC > comodulogram”.
Thank you very much for your prompt response.
Best regards,
Rock
Hello,
I perfomed the inter regional PAC analysis for each condition and for each subject. I would like to test the difference between two conditions. In fieldtrip I would use ft_freqstatistics but I would need a value for each subject, for each time and freq point. Is there a way to export this information from brainstorm or to do directly this type of test with the program? Thanks in advance. Manuela