= Bad channels =
''Authors: Francois Tadel, Elizabeth Bock''

<<TableOfContents(2,2)>>

= From auditory =
== Bad channels ==
 * During the visual exploration, some channels appeared generally noisier than the others. Example:
  . {{http://neuroimage.usc.edu/brainstorm/Tutorials/Auditory?action=AttachFile&do=get&target=badchannel02.gif|badchannel02.gif|height="200",width="456",class="attachment"}}
 * Right-click on '''Run01 '''> Good/bad channels > Mark some channels as bad
  . > '''MRT51, MLO52'''
 * Right-click on '''Run02 '''> Good/bad channels > Mark some channels as bad
  . > '''MRT51, ''''''MLO52, MLO42, MLO43'''

= From CTF =
== Bad channels ==
If you find   out that a sensor has unexpected values, that are not coherent with  the  other surrounding sensors, you can choose to ignore it in the  displays  and in the source estimation process. In the channel file,  each channel  has a flag which indicates if it is good or bad. You may  also import  recordings files that already have some bad channels  defined.

 * Select   a few channels with one of the method described above: click on the   time series, click on the sensors dots, right-click and move to select a   group of sensors. Then right-click in one of the figures and check out   the '''Channels''' sub-menu:
  . {{http://neuroimage.usc.edu/brainstorm/Tutorials/TutExploreRecodings?action=AttachFile&do=get&target=channelMenu.gif|channelMenu.gif|class="attachment"}}
  * '''View selected''': Show the time series of the selected sensors

  * '''Mark selected as bad''': Remove sensors from the display and all the further computations

  * '''Mark non-selected as bad''': Keep only the selected channels

  * '''Reset selection''': Unselect all the selected sensors

  * '''Mark all channels as good''': Brings back all the channels to display

  * '''Edit good/bad channels''':   Opens an interface that looks like the channel editor, but with one   extra column to edit the status (good or bad) of each channel.

 * '''Mark channels as bad''': Right-click > ''Channels > Mark selected as bad'', or press ''Delete ''key.   The sensors should disappear in all figures, and the topography view   (2D sensors cap) is updated so that the interpolation on the 2D surface   now ignores the bad channels.
  . {{http://neuroimage.usc.edu/brainstorm/Tutorials/TutExploreRecodings?action=AttachFile&do=get&target=channelSetBad.gif|channelSetBad.gif|class="attachment"}}

 * '''Get the channels back''': two options
  * Right-click on figure > ''Channels > Mark all channels as good<<BR>>  ''

  * Right-click on figure ''> Channels > Edit good/bad channels...''   : this menu open a window very similar to the Channel Editor window   introduced in previous tutorials, but without the annoying location and   orientation values, and with green and red dots. Click on the dots to   mark a channel as good or bad.
 ''' {{http://neuroimage.usc.edu/brainstorm/Tutorials/TutExploreRecodings?action=AttachFile&do=get&target=channelEditGoodBad.gif|channelEditGoodBad.gif|class="attachment"}} '''
  * Note   that if you click on a row in this window, it will select the   corresponding channel in the time series and topography figures.
  * Close this window to save the changes.

 * '''Batching this from the database explorer''':
  * You will find a "Channels" menu for any node in the tree that contains recordings.
  * If   you do this on the level of a node, the operation will be applied   recursively to all the recordings contained in the node. This way, you   can quickly set that the channel 63 is always bad, or that electrode 43   is not working for subject #12, without having to visualize all the   recordings one after the other.
  * The'' View all bad channels'' command displays the list of all the bad channels in all the files in the ''Messages ''tab, in main Brainstorm window. {{http://neuroimage.usc.edu/brainstorm/Tutorials/TutExploreRecodings?action=AttachFile&do=get&target=channelTreePopup.gif|channelTreePopup.gif|class="attachment"}}

 * '''Important notes''':
  * The good/bad channel flags are stored in the recordings files, not in the channel files. So if you marked some channels as ''bad ''in the ''ERF ''data file, there are still considered as ''good ''in the ''Std ''data file.

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ADD BAD CHANNEL MONTAGE
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Website feedback:

{{{
Comments: Bad channels
- Get the channels back
-- Note that if you click on a row in this window, it will select the
corresponding channel in the time series and topography figures.
--> This seems not work. I am using Brainstorm(3-Mar-2015)/Matlab_R2014a/Yosemite 10.10.2
}}}
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