Contents - Index

Alpha-Theta Display

Alpha-Theta Display

The feedback consists of two environmental tones signaling the general range of the client's state-of-relaxation, and tones that signal momentary bursts of EEG in one or the other reward band. The alpha environment (trace 3) is a running stream, and its tone is a high-pitched bell. The theta environment (trace 2) is ocean waves, and the theta tone is a low-pitched bell. As relaxation deepens, the ongoing environmental sound will cross-fade from stream to ocean and low-pitched bell tones will replace the high-pitched tones. In cases where both frequency ranges are over threshold at the same time, the system is biased toward signaling the trace 3 state.

Since the client station screen is not needed for visual display, it is used to display extra therapist information in the form of a line graph depicting amplitude over time for the two reward traces and the inhibit trace.

Alpha-Theta Volume Controls

The default volume levels for the background sounds and reward tones are set to a percentage value.

Theta (ocean wave) volume

Alpha (babbling brook) volume

Alpha reward (bell) volume

Theta reward (gong) volume

The next-to-last option adjusts the master volume. The last option adjusts the fade or rate-of-change speed used when switching between the wave and babble sounds.

At the bottom of the Alpha-Theta display are the "names" of the sounds along with the relative percentage of the two signals (alpha and theta). When a tone is generated, the appropriate "name" for the tone displays during the playing of the tone. The "Step" value is the current setting of the fade step value which controls how rapidly the environmental sounds transition.

The ALT-P key combination saves the current display screen to the PRINT directory.