Superhuman Senses

Our five senses--sight, smell, hearing, taste, and touch--construct the reality of the world around us, like a blank canvas continuously painted and repainted over every day. For each person, this portrait of reality is slightly different, but we more or less agree that the sky is blue, lemons are sour, and horns are loud. But what about when one or more of your senses is heightened, changed, or even taken away all together? Do people with these radically-altered senses show us that each of us has limitless sensory potential, waiting to be unlocked? And is it possible that we have a mysterious "6th sense," one that is currently UnXplained?