: Thrall have a very limited consciousness, but it does
: exist. There are occasional references to a warrior's
: prowess (once about some Berserks, and once about
: Alric, I think) causing them to be afraid or
: horrified; and there's one picture of some marching
: Dark units, with a Ghol pissing a Thrall off.
: Think of them as kinda like the movie Frankenstein.
: They're really really dumb--like guinea-pig level--but
: they *can* feel somewhat. And, as Dan says, they
: probably don't feel very good most of the time.
: --SiliconDream
The Ghast reference in GURPS (Thrall reference points to this for info) says that they don't really "think or have a personality". Apparently if you were to remove the Slave Mentality and Reprogrammable Duty disadvantages, you might create a more conscious creature, horrified by itself.
However, despite this, it's true that it does also mention that they occasionally have spurts of visions of things from their former lives, so it seems reasonable to assume that they're not completely brain dead all the time. Just some of the time. Much like myself.