Valve is always looks around to see what people want in their next game, and so far it has mainly been done by watching people play, how they react, what they like or dislike. But according to a recent interview with Valve co-founder Gabe Newell the Half-Life developer wants to go further by measuring brain activity using "new technologies where we can wire players up with EEGs and actually have direct exposure to their physical reactions to the games," so "know for sure of something is actually frightening the player--their heart rate is going up ... appropriate parts of their brains are being activated"