Practice EEG Session
With or without knowing HOW you can begin to control, for short periods of time, the target activity. For a sample session we suggest a simple session watching the “Inhibit” target bar and trying to keep the colored signal bar below the target line as much as possible.
Connect amplifier to computer
Connect your amplifier cable into your amplifier and then to the computer’s USB port or follow manufacturer’s instructions for connecting.
Open a simple design
In Brain-Trainer for BioEra, FRE1+ with 1 channel selected, set Inhibit 1 to 2 – 38 and uncheck the other two thresholds.
In BioExplorer, Sample Session Brain-Trainer design simply provides feedback on a single band.
You must ALWAYS have a ground and at least one reference. It may not be specified in the Montage.
1. Ground: Place electrode (AFz in caps).
2. Active: Place electrode at Cz.
3. Reference: Place electrode on or behind right ear (A2).
You MUST have a ground (Most amplifiers use one ground for all channels), and the ground can go anywhere on the body (such as the other ear).
Conductant for sensors
Saline electrodes (e.g. for TC26 cap) should already be saturated. Gel caps (e.g. Electro-Cap) should be gelled at this time.
Plug Electrodes into Amplifier
The “montage” listing shows you which sites on the head go to which inputs in each channel.
The montage above shows:
Cz on the head plugs into the 1/A+ input
A2 (right ear lobe) plugs into the 1/A- input
The ground (AFz) is plugged into gnd/VG
You must ALWAYS have a ground.
You MUST have a ground (most amplifiers use one ground for all channels), and the ground can go anywhere on the body (such as the other ear). It may not be specified in the Montage.
Look at the amplifier, and you’ll see that the inputs to plug the electrodes into are marked 1+, 1- or A+, A-, etc. Each channel of EEG (you can train one channel, two channels, 3 or 4 channels at a time) has:
a. One “Active” electrode (which goes into the + input)
b. One “Reference” electrode (which goes into the – input
c. A Ground or neutral electrode (which goes into the gnd, G or N input)
The Q-wiz and Optima have channels 1/A and 3/C sharing a reference and channels 2/B and 4/D sharing a reference.
Start Session
We look at the power spectrum. Pay attention to the spectrum analyzer and oscilloscope displays. Notice where the slow waves are, where the fast are. Focus on the tallest bars and try to make them go down just by looking at them. Record a couple minutes of data.
a. The spectrum analyzer should be set to show to 60Hz. Especially look for very tall bars at 50 or 60 that don’t seem to change much or for very tall spikes that occur at regular intervals on the spectrum. These are indications of electromagnetic artifact—electrical environmental noise masquerading as EEG.
b. The oscilloscope should show a waveform with a variety of amplitudes (heights) and a variety of widths (frequencies). The more regular and consistent it is, the more likely it is not coming from the brain. Sharper wave tops and bottoms are more likely artifact than rounded ones.