Throughout the BBC Horizon show "The Secret You" the idea of
consciousness is considered. "Where does consciousness reside?"
being one of the many prompts given for this video. To describe
where consciousness comes from, we also need to define what
consciousness itself is. Within the brain stem is a group of
nerve cells called the reticular activating system. These nerve
cells send signals to the thalamus, which acts as a "relay
station" to send signals to different areas of the cortex. To
quote the video, "consciousness appears to be all about constant
activation of the cortex." In the last ten minutes of the video
they talk about conscious and unconscious brain activity.They
show scans of a brain that is awake and also of the same brain
when it is asleep. When the brain is awake it will trigger other
parts of the brain after another part of the brain was
stimulated, but when the brain is asleep the stimulation remains
localized and does not trigger other parts of the brain, as is
does when you're awake. If