Our five senses - hearing, sight, taste, smell, and touch - play indispensable roles in our life experiences. For most people, our five senses seem completely discrete and easily distinguishable; however, our senses are in fact related profoundly to each other in a complex way. When our senses collide, synesthesia occurs; a condition in which the stimulation of one sense involuntary triggers the activities of other senses. This phenomenon was first discovered dated to 1812; it was defined as a "neurological condition  that does not often interfere with normal daily functioning (Lynn). Synaesthetes perceive their surrounding differently from others: to them, every weekday has its spacial arrangement, words are full of flavors, and every letter can be seen with colors. Almost every sense can be "mixed (and sometimes more than two senses) under the condition of synesthesia, but the most common forms of synesthesia experience are color-grapheme synesthesia (Van Driel) and moth-space synesthesia (Liana); sometimes, both of the conditions may occur at the same time. People with color-grapheme synesthesia perceive particular colors when they see (or hear) different letters or numerals. Every synesthete has their own colors for each letter and number, and scientists have proved that the colors they see are not imagination but actual perception; meaning a color-grapheme synesthete would not need to think about what is the right color for the letter "A", but the color, for example, red, is inherently built in to the letter "A." To a synesthete, it is evidentially true that "A" is red; they actually perceive "red" and "A" at the same time. Moreover, most synaesthetes are especially sensitive to sequential arranged things, such as numbers, days in a week, months in a year, and even years themselves. Generally among moth-space synesthesia, synaesthetes experience months in spatially defined configurations. For example, twelve months are arranged as a "spiral clock  around the synaesthetes; each month is fixed at the same angle; as the time goes on, the indicator of time follows the track of the spiral and circles towards the outside. Sometimes colors are perceived from the months as well; a synesthete would say, "The yellow September in this year is in front of me, and the blue March in next year is further from me at my back."  An interesting experiment was done by Megan Steven's research group from Oxford University. Their subject, John Fullwood, is a synaesthete who see colors when he hears particular words, such as days of the week and months of the year. What is uncommon about Fullwood is that he had retina disease so that he progressively became blind over the year. He did have sight and could see colors when he was younger, so he knows what colors are. For more than ten years Fullwood lived in darkness; however, he does see colors through his synesthesia. To him, weekdays are arranged in an ellipse. Each half of the ellipse is a full week: one half refers to the current week and the other half is the future week. In Fullwood's mind, Monday is white, Tuesday is orange, Wednesday is grey, Thursday is ochre, Friday is sienna, Saturday is olive, Sunday is blue, and next Monday would be white again. A question arose: Fullwood has been blind for years, in theory, he does not perceive real colors form the out side world so that the part in his brain that is in charge of color processing could not be activated for any reason, if his synesthesia is only his imagination, unless there are actual signal of colors tra