How to know name of a channel from power.plot_topo

💬 Support & Discussions
1
  • MNE version: 1.1.1
  • operating system: macOS 12.3

Hello! I know the first line below plots the general power spectral density, and from the graph I can decide which channel specifically to plot, by using the second line and specifying the channel type in title=power.ch_names([2])

power.plot_topo(baseline=(0, 0.5), mode='logratio', title='Average power', vmin =-3, vmax =+3)
power.plot([1], baseline=(0, 0.5), mode='logratio', title=power.ch_names[2])

However, I don’t know which ch_name number refers to a each specific channel. I can infer that 2 is F3 by plotting it, but I am missing the main link here.

Also, I followed this tutorial , but I am struggling to understand how exactly to read the power plots. I get the coding parts, but I don’t understand the graphs.
Is there by chance a tutorial on reading those graphs?

Thank you so much!

2

Hello,

First of all, you don’t need to work with indices. You can provide the selection of channels as names.

from mne.time_frequency import read_tfrs

tfr = read_tfrs(fname)[0]
tfr.plot(
    ["C3", "CP3", "C4", "CP4"], 
    baseline=(2, 6), mode="logratio", title="auto"
)

Yields 4 plots for the given channels, with the title set as the channel name.
You can also combine channels with the argument combine, thus yielding a single plot.

tfr.plot(baseline=(2, 6), mode="logratio", title="auto", combine="mean")

Mathieu