My feeling is that the task of facing towards the brightest light in the room is too simple to provide a basis for developing a neural network example program.
Braitenberg got a lot of great mileage in thinking about his simple vehicles (the basis for the OP's post) as models for simple sensor/response behavioral systems.
For example, simply crossing the wires leading from the sensors to the motors leads to astonishingly different behavior compared to uncrossed.
These thought experiments become very popular and A. K. Dewdney published a good summary in Scientific American some years ago (attached PDF). It is really fun to read and highly recommended!
Braitenberg_vehicles.pdf (1.01 MB)