in a game like eternal darkness the vs could be linked to the sanity gauge. in other games it could be linked to the eniroment or music. still in others it could be link to character movement. the higher the stress levels or pulse could make the characters move faster,increase the music tempo,warp platforms,shift the environment around. imagine a survival horror game where the amount of response the vs gets the easier the enemies detect you the faster you move and the harder for your character to function.