27
®
ArC Instruments Ltd.
STDP
Perform Spike-Timing-Dependent Plasticity measurements by iteratively applying a voltage series
given by the difference of two pre- and post- synaptic voltage spikes with configurable delay.
Load Pre Spike:
browse to load a voltage series text file which will define your
Pre- spike. For example, the Pre- and Post- pulses displayed in Figure 31
above were defined in the text file shown on the left. When writing your own
spike txt files, make sure the first and last point series has 0V. A few spike txt
files can be found in ArC Control/Helper/.
Identical Spikes checkbox:
When checked, the Post- spike will be identical to
the Pre- spike. Uncheck to be able to load a different Post- spike.
Load Post Spike:
browse to load a voltage series text file which will define
your Pre- spike.
Scale voltage
and
Scale time
: scale Pre- and Post- voltage spikes in
amplitude and duration.
Voltage (V), time (s)
spike_2.txt
When a Pre- or Post- voltage spike are loaded, both are plotted on the figure on the right of the
module panel. Bottom figure shows both spikes with a corresponding time delay
dt,
and top figure
shows the difference between the Pre- and Post- spikes, which also represents the actual voltage
series applied on your test device during an STDP event with that corresponding
dt.
Move the bottom
slider to visualise how the resulting waveform changes with varying
dt.
Time step (ms)
sets a time step which is used when iterating through STDP events when the
experiment is running.
For example in the figure above, Pre- and Post- spikes are identical, and their maximum duration is
1ms. Time step(ms) is set to 0.1ms=100us (henceforth referred to as timeStep). By clicking on
Apply to
…
,
the experiment will proceed as follows: First, the resulting waveform of Pre-Post with
dt
=0s will be
applied, followed by the resulting waveform for
dt
=+timeStep, then for
dt
=-timeStep, then for
dt
=+2*timeStep, then for
dt
=-2*timeStep and so on, until
dt
becomes greater than the duration of the
longest spike (in this case both Pre- and Post- are the same at 1ms).
Only single event checkbox
: When checked, only the STDP waveform shown in the top right figure is
applied, one time, when clicking
Apply to
…
.
Use this feature to check how a single STDP event might
influence the conductance of your device. Uncheck for normal operation like described above.
Figure 31: STDP module interface.
0, 0
1, 0.0001
-0.5, 0.0002
0, 0.001
