There is software that tries to change brainwaves or related mood, stress and other states throught sound or other stimuli (sound, pictures, video etc).
Neuroprogrammer 3+biofeedback is an interesting toy but only software I managed to find.
Resonanz (resonanz.sourceforge.net) is pre-alpha-version (not yet fully working) software/research program/tool for Linux. (waiting for Emotiv Insight BCI release – the software will use it to select the best stimulus which pushes brain towards the target state). [the only missing part is emotiv measurements/now there is a stub virtual device giving random responses].
The idea is:
1. Collect brain stimuli, response pairs to a large database
2. Learn mathematical model f(state, stimuli) = response state from the measurements (machine learning)
3. Find the best stimulus that moves brain toward a target state as well as possible (similarly movies or music may change your mood but hopefully better if you match stimulus (picture etc.) exactly to the current emotiv metastate (affectiv).
4. Keep measuring a nervous system state and keep finding the best stimuli to push CNS into a target state (emotiv affectiv/meta signals)
5. sell the program, or movies and the BCI device.
6. user sets a target state he wants to reach and program keeps measuring and showing/playing pictures/sounds based on continuous measurements that pushes brain towards the target (less anxiety, better mood, relaxation etc)
..is an interesting somewhat related project which can be good source of pictures.
It is interesting that the big pharma and governments put millions in a drug development and use knowing that side-effects can kill while there is zero development in cns stimulation based methods that do not have that many side-effects: talk, electroacupuncture, exercise, tens, audio, pictured, video. (computer generated stimulus + feedback (emotiv insight etc) to guide cns changes).