Making things appear before one's eyes

Francis Burton fburton at nyx10.nyx.net
Mon Oct 6 04:50:46 EST 2003


Is anything known about the mechanism operating in the
curious visual "illusion" in which shapes can be created
at will (after a little practice) out of the kind of
white noise that used to appear on TV screens when the
TV is not tuned to any channel?

If you are not aware of this effect, you might like to try
it for yourself. Stare at a field of "TV snow", trying to
find patterns in the random fuzz. You may, for example,
see vertical bands moving alternately up and down, or
concentric rings. What you may then discover is that you
can decide what you will see next. You can cause one shape
or "flow" to switch/shift to another of your choice. It
feels slippery at first, like popping a Necker Cube - but
with practice one can conjure up patterns at will.

In my experience, there are limits to the complexity of
the shapes. I haven't been able to get beyond fairly basic
geometric forms. This may offer clues about the mechanism.

Has this effect been described in the literature? Does it
have a name?

Francis



More information about the Neur-sci mailing list