What is the effect of every button in the Gauntlet Bridge Puzzle of Dragon Age:Origins?

In Dragon Age, there is a mini-game related to the quest for retrieving the Sacred Urn of Andraste's Ashes from an ancient temple.

The mini-game is known online as Gauntlet Bridge Puzzle, and it looks like this:

There exist plenty of sources which provide the solution for this mini-game.

Instead, I would like to know what is the effect of pressing each button individually, assuming a naming convention as follows:

 EXIT
L6 R6
L5 R5
L4 B4 R4
L3 B2 R3
L2 B2 R2
L1 B1 R1 START

e.g. by watching this video, I was able to deduce that R2 semi-activates B1 and B2. Unfortunately, not all buttons are being pressed in this video so it is hard to reconstruct the whole situation from it.

Can anyone playing this game help?

(note: I am currently unable to play this game)