In this MIT Technology Review article. Some firms are using tech to monitor our eye and facial responses to various stimuli to not only determine our emotional responses but to manipulate them toward a particular result. Our facial expressions often reveal our nonconscious preferences and are thus more easily manipulable. One factor is the delay in our responses from a stimuli, indicative of indecision and thus more easily manipulated. The faster the response the harder it is to change the opinion. Something to think about for those of us who like to take our time to consider many variables.