We have now released the PLUS module, an additional device that works in connection with our XCSITE 100 stimulator. We have designed this device based on feedback we got from you! In essence, the device provides two signals (accessible via standard BNC connectors on the front panel). One signal is proportional to the stimulation current and the other signal is proportional to the applied voltage. Both are isolated from the stimulator with optocouplers rated at 4000 Volts.
What can you do with the PLUS module:
(1) Get involved in the discussion of impedance fluctuations and non-linearities
Remember that tDCS/tACS is current stimulation, meaning that the current is pre-defined and the voltage changes such that the correct current is delivered as a function of impedance. The impedance can fluctuate during stimulation (as the contact of the electrodes with the skin changes). Also, a recent paper by the group of Dr. Siegel suggested that there are physiological process that modulate the impedance. Note that this paper has caused quite some debate, including a rebuttal by Dr. Herrmann (full disclosure, a collaborator of the Frohlich Lab). With PLUS module you can track both current and voltage, record it with your preferred data acquisition system, and join the exciting debate!
(2) Study cognitive processes as a function of tACS phase
There are numerous papers suggesting that the phase of the oscillation modulates cognitive performance. Now you can test this hypothesis in a causal way by applying tACS and apply stimuli/trials relative to the phase of the simultaneously recorded stimulation waveform.
(3) Monitor the stimulation in real-time if you do not mind being unblinded about the stimulation condition
The PLUS module gives you the opportunity to monitor both current and voltage in real-time. You can connect it to an oscilloscope or any other device since the connection to the stimulator is isolated from the BNC connectors of the PLUS module.
(4) Record the stimulation waveform together with the EEG for enhanced artifact removal quality
If you are interested in the challenge of recovering the true EEG waveform in presence of a huge stimulation artifact, including the time series of the stimulation current and stimulation voltage into your ICA will likely make a big difference.
(5) What are your ideas?
Let us know and we will happily discuss them with you.
You can now order the PLUS module in our webstore, for a limited time we offer it with a discount to our early pioneers / customers.