Billy wakes up in a vast white dome with a white floor. All around him as far as he can see is white nothingness. Then he turns around and looks behind him. On the ground lies a flat, red, six-inch disk. He notices this disk and it draws his focus. The rest of continuous whiteness means nothing now; it is just background noise. This red disk is the only thing of significance in Billy’s short perception of reality. Keep in mind that although Billy’s senses perceive something that we define as red and round, he does not mentally categorize this object as a red disk. Both “red” and “disk” are concepts that he hasn’t learned yet. So although this object represents Billy’s sum current perception of reality, it means nothing to him. He has no concept of what it represents.