People become aware of themselves between the ages of 18-24 months, but what changes for this to happen? We don't just wake up one morning and all of the sudden know that we are ourselves. What part of the brain activates our consciousness? According to the video "BBC Horizon-The Secret You" there is no one part of the brain that holds our consciousness. In fact it is actually a complex process that does this. According to "The Secret You" it all starts in the Reticular Activating System, which is a group of diffused nerve cells in the brain stem. This sends projections to the relay system known as the Thalamus, which then sends these projections throughout the Cortex. Consciousness is constant activation of the Cortex. So when do we consider someone to be out of consciousness? Do we consider someone to be out of consciousness when they are in a vegetative state? A researcher from "The Secret You" video is finding evidence on the contrary. When people that are in vegetative states were asked to imagine themselves playing a tennis match the same part of their brain was activated as the healthy volunteers who were asked the same question. In a sense they were acknowledging that they were being asked a question and reacting to that question. Does this mean they still have consciousness? Is it wrong then to take someone off life support who can still process in their mind thier surroundings? When should people be considered brain dead or out of consciousness? I am interested in what people have to say on this topic.