Electrode Selectivity; Reference Selection - imec NEUROPIXELS 1.0 User Manual

Most of these functions are already implemented in the application software packages mentioned in
Section 2.4.1 and are described in the respective online
Below, we will briefly describe the electrode selectivity and reference selection.

Electrode Selectivity

Since the shank has 960 electrodes and the base 384 channels, there are 2.5 virtual banks of 384
electrodes in the shank (Figure 34). Therefore, each channel can connect to 2 or 3 electrodes. The
connectivity between electrode and channels is given by this formula:
Channel N => Electrode (1+N+384*A), where N = 0:383, A=0:2
For example, channel 0 can be connected to electrode 1, 385 or 769, while channel 199 can connect to
electrode 200 and 584 (Table 7).

Reference Selection

Three reference inputs are available for each channel:
External reference: multiple input pads are located on the probe flex. Separate wires can be
•
soldered to these pads.
Tip electrode: a large TiN electrode located at the tip of the shank.
•
Internal reference: this input can connect to recording electrodes 192, 576 or 960 (i.e. one in
•
each of the three electrode banks)
The reference selection is channel-independent, and each channel can only connect to one of the three
reference inputs simultaneously. Moreover, the internal reference can only connect to one of the
available three internal electrodes, which are spaced 3.84 mm apart.
NEUROPIXELS 1.0 USER MANUAL V1.0.5
Figure 34: Electrode bank distribution along the shank
Table 7: Electrode-channel mapping
Bank number 0
Channel
Electrode
0
1
1
2
... ...
383
384
User Manual
and
Bank number 1 Bank number 2
Electrode Electrode
385 769
386 770
...
768
Documentation
.
...
35