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Do you hear anything when viewing the moving dots? Play the movie repeatedly for best effect. We are studying this phenomenon of hearing motion in the Koch Lab at Caltech in Pasadena, California USA. It is a previously undescribed form of synesthesia, a benign neurological condition associated with cross-activation of the senses. We don't know yet how common "hearing-motion syesthesia" is, but preliminary estimates are in the range of 1 in 100. FAQ What do people hear?Common responses to this particular movie include "whooshing", "whirring", "bubbling", "scratching", "sounds like breathing or a heartbeat", or "sounds like water flowing". Some people report that the pitch of the sound changes when the dots go in and out. I don't hear a sound, but I can imagine a sound. Is that synesthesia? Most people don't automatically associate a sound with the movie, but could imagine a sound if asked to. A smaller number report feeling automatically inclined to imagine a sound, but recognize it as imagery and can stop the association by thinking about something else. Others describe "sound-like" sensations which seem stronger than imagery but are still weak and perhaps inconsistent. They might wonder if they are only hearing something because they are trying to for the test. In clear-cut cases of synesthesia, people clearly and automatically hear a sound as long as the movie is in their view. They cannot turn it off or on. The clear synesthetes also hear sounds to other visual displays of motion and flicker, such as television with the sound turned off or natural movements like the fluttering of butterfly wings. They have experienced this sensory cross-activation for as long as they can remember, going back into childhood. This continuum of responses is one reason I suspect that "hearing-motion" synesthesia might represent an exaggerated form of normal communications that occur between the auditory and visual processing systems in the brain. If there is indeed a continuum of experience, then it is somewhat arbitrary where to draw the line and call it synesthesia. If you are curious about yourself, try paying attention to sounds throughout the day to find more examples. All of the synesthetes included in our study (see next question) met the latter conditions listed above. Can you prove that the sound perception is real? Our goal was to develop a task in which synesthetes would perform better than others if their sound perception was real. This would be a convincing objective test because it's hard to fake being better. We showed that synesthetes performed much better than non-synesthete controls at identifying simple rhythmic patterns of flashing light, similar to visual Morse code. Normally, people are better at identifying rhythmic patterns with sound than with vision. The syensthetes had an advantage at the visual task because they not only saw but also heard the visual flashes. Saenz and Koch (2008). The Sound of Change: visually-induced auditory synesthesia. Current Biology. Does hearing-motion synesthesia occur with other types of synesthesia? Sometimes yes, sometimes no. One of the participants in our study also experienced colors when listening to music. I have since heard from people with other types of synesthesia (such as associating numbers & letters with color) who believe they also have hearing-motion synesthesia. It seems that various forms of synesthesia can co-occur and also stand-alone. How do you spell it? "synesthesia" is more common in the US, "synaesthesia" in the UK. Links to find out more about synesthesia: Synaesthesia Research Page Synesthesia Wiki page The Synesthesia Battery (includes tests for several types, in particular those involving color perception) Other Links: Koch lab website Saenz's website Mind Science Foundation (funding this research) Thanks for your interest, |