Edit the probe's channel-by-channel settings, for example:
Default
sets all channels to these values:
No file is needed with defaults; they are built-in.
Customized settings always have to be saved to a file. It has extension (.imro) = Imec readout
.
In all cases, default or custom, the active settings are also stored in the run-time meta file with tag:
~imroTbl
.
The big table on the left shows a row for each readout channel. You can type directly into this table to make choices just for that channel.
These are located to the right of the table. These helpers provide a convenient way to assign a given value to all channels.
This positions a 384-channel readout block (region of interest) anywhere along the length of the shank. You can use it to capture observed activity. Follow these steps:
First decide where the center of interest/activity is on the probe. You can set all banks to zero, one or two, or load an interesting long column pattern available from the download site here. Start a run and open the Shank Viewer to see activity. Hover the cursor over the shank to read out a row number at the center of your region of interest. Write it down.
Open this dialog. Either configure a new run, or right-click in the Graph Window traces for this probe and select Edit Banks, Refs, Gains
. In the dialog, type the row number into the Row
box and click Center Here
. This will select a continuous block of electrodes centered at that row by assigning the correct bank numbers for you.
Optionally, to make your graph ordering reflect the new electrode assignments, open the Channel mapping
dialog for this probe. Either configure a new run, or right-click in the Graph Window traces for this probe and select Edit Channel Order
. In the dialog, select Shank: Tip to Base
in the Auto-arrange
menu and click Apply
. Now save this channel map. Remember that a channel map is only used to order the graphs in the viewers, and that to make it take effect, you have to click the sort button in the Graphs window panel so it reads Usr Order
.
The probes use switches to select the bank that each readout channel is connected to. The relationship is this:
There are five reference choices [0..4] for each channel.
Refid Referenced site
0 external
1 tip electrode
2 electrode 192
3 electrode 576
4 electrode 960
In practice you should never select the on-shank references (choices 2,3,4) because they don't work well: In saline amplitudes referenced to these sites are not effectively cancelled.
Each readout channel can be assigned a gain factor for the AP and the LF band. The choices are:
50, 125, 250, 500, 1000, 1500, 2000, 3000
Imec channels are separated into two filtered bands as follows:
NP 1.0 probes read out both an AP and an LF band.
fin