The name is absent

136

across the saline medium (NeuroExpIorer 4 was used for these and the following
illustrations). As shown in figure 2A the Stim Project is set to stimulate and a stimulus
waveform is triggered at t=0.745s, which is immediately picked up by the electrodes not
connected to the Stim Project. The channels connected to the Stim Project show a
fluctuation at the time of switching. At time t=2.745 the Stim Project is switched to
record (fig. 2B) and the saline waveform triggers (after a programmed 5ms delay so that
the transition can be easily discerned). As can be seen in the figure the Stim Project
channel is not able to immediately record the saline waveform, but the neighboring
channels can (in another recording not illustrated here the 5ms delay was turned off to
verify that the neighboring channels are capable of recording in less than a millisecond).
As shown in figure 2C, the Stim Project channel is not capable of recording the saline
waveform until after a delay of nearly 3 seconds. It takes another 40ms for the
recording to reach maximum amplitude (fig. 2D).

This experiment was repeated with a variety of different stimulus waveforms
(monopolar and bipolar square waves, sinusoids, sawtooths, and triangle waves) with a
variety of amplitudes (0.1-5V_pk) and a variety of frequencies (500-10,OOOHz). In each
case the Stim Project channels were unable to record until after a delay of 3 seconds
±50ms. The neighboring channels were always able to record without a measurable
delay. The experiment was repeated again without a stimulus waveform (fig. 3) and
again the channels connected to the Stim Project had a delay of almost 3 seconds
before being able to record while the neighboring channels had no discernable delay.
This demonstrates that electrode capacitance is not an issue in the recovery time, and

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