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%matplotlib inline

Compare evoked responses for different conditions

In this example, an Epochs object for visual and auditory responses is created. Both conditions are then accessed by their respective names to create a sensor layout plot of the related evoked responses.



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# Authors: Denis Engemann <denis.engemann@gmail.com>
#          Alexandre Gramfort <alexandre.gramfort@telecom-paristech.fr>

# License: BSD (3-clause)


import matplotlib.pyplot as plt
import mne

from mne.viz import plot_evoked_topo
from mne.datasets import sample

print(__doc__)

data_path = sample.data_path()

Set parameters



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raw_fname = data_path + '/MEG/sample/sample_audvis_filt-0-40_raw.fif'
event_fname = data_path + '/MEG/sample/sample_audvis_filt-0-40_raw-eve.fif'
tmin = -0.2
tmax = 0.5

#   Setup for reading the raw data
raw = mne.io.read_raw_fif(raw_fname)
events = mne.read_events(event_fname)

#   Set up amplitude-peak rejection values for MEG channels
reject = dict(grad=4000e-13, mag=4e-12)

# Create epochs including different events
event_id = {'audio/left': 1, 'audio/right': 2,
            'visual/left': 3, 'visual/right': 4}
epochs = mne.Epochs(raw, events, event_id, tmin, tmax,
                    picks='meg', baseline=(None, 0), reject=reject)

# Generate list of evoked objects from conditions names
evokeds = [epochs[name].average() for name in ('left', 'right')]

Show topography for two different conditions



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colors = 'blue', 'red'
title = 'MNE sample data\nleft vs right (A/V combined)'

plot_evoked_topo(evokeds, color=colors, title=title, background_color='w')

plt.show()