Synesthesia (or synaesthesia) is loosely defined as "senses coming together." At its simplest level, synesthesia means that when a certain sense or part of a sense is activated, another unrelated sense or part of a sense is activated concurrently. For example, when someone hears a sound, he or she immediately sees a color or shape in his or her "mind's eye." The Synesthesia Project's website presents an abundance of information about this phenomenon including a thorough FAQ section, which answers questions such as "How common is synesthesia?" and "Is there any proof that synesthesia occurs?" In addition, visitors can find details about the Vision and Cognition Lab located at Boston University. Finally, the site includes the opportunity for visitors to participate in two of their web-based experiments.