"Diagnosis" literally means, "through knowledge." On clinical grounds, synesthesia is diagnosed when the perceptions are:
  • Involuntary, but elicited. Synesthesia happens to people, and the stimulus that sets it off is easily identified.
  • Projected--experienced not in the mind's eye but outside the body. The only common exception is in those in whom synesthesia consists only of colored letters and numbers.
  • Durable--a given synesthete's associations remaining the same over a lifetime.
  • Generic--radially symmetric, scintillating, or wavy shapes:

    agreeable or disagreeable tastes; elementary tactile sensations. Synesthesia is NEVER pictorial, elaborate, or a fully complete object.

  • Memorable. While comments like, "she had a green name," are common, it is the sensation (green), and not the attached meaning (the name) that is vividly remembered for decades.
  • Emotional and noetic--synesthetic experience is accompanied by a sense of certitude, or even a "eureka" feeling. They seem not just state of perception, but of knowledge.
    return to synesthesia