Having selected either the Calibration button or the Motor Imagery button (3 or 4) for the session, the Start Stream button connects the Ganglion and begins the flow of packets of data to the computer via its Bluetooth link.

The Stop Stream button ends the session and writes the summary logs to a file.

Before the session is started, the user must select whether it is a Calibration session, to record the levels of activity at the electrodes without any motor imagery so that during an imagery session, the values can be adjusted to help to isolate the activity due to the imagery. It records these values to a file.

If a Motor Imagery session is selected without doing a Calibration run first, then the values from the most recent Calibration session are read from the file and used.

The C3, C4, P3 and P4 labels are from the 10-20 convention for the positioning of electrodes when doing an EEG.  In this case, we are using C3 and C4 a left and right hemisphere position above the motor cortex. P3 and P4 are a similar left and right hemisphere positioning but above the parietal cortex.

The dark blue circles represent the relative power of the beta frequency range between the left and right hemispheres.  The top set are C3/C4 and the bottom are P3/P4.

The paler blue expanding and contracting circles are similar but for the mu frequency band.

Above each electrode position are two blue numbers which represent the band power  percentage share for that hemisphere.  Mu is the left hand figure (with the 8 label above it) and beta above the right side of each electrode.

These numbers show the calibration band powers, mu below the left side of each electrode and beta below the right.

At the top of the screen, when the session is Motor Imagery, a prompt is shown to ask the user to concentrate on imagining movement of one side of the body or to imagine stillness if the prompt is Centre.  These prompts  occur in a random sequence and last for a random number of seconds.  During Motor Imagery, higher brain activity occurs in the hemisphere on the opposite side of the brain to the prompt.  Counterintuitively, this activity results in a reduction of the band power in the mu frequency band so the hoped for outcome in for the paler blue circle representing mu power to shrink on that side.  The circle on the side of the imagined movement should therefore swell in response since the pair represent the ratio between the two electrodes at that frequency. Beta frequencies may have a similar response but less pronounced according to my sources. The prompts are spoken when they change and a tick runs during the prompt.