The preceding write-up is incorrect; successively-activated lights do create the
illusion of motion, but this is not the autokinetic effect.
Your eye muscles are tired. Right now. We know
this because they're always tired, but it's okay because
you have a lot of them and they're not all tired
at the same time. This means that your eyeballs are caught in a sort of
tug-of-war between their fixating muscles, and being
basically gobs of stale jell-o they are always moving and flexing very
slightly as a result. This is not normally a problem because your brain is smart as hell and corrects for these movements
by using reference objects in the field of vision.
So, you know how sometimes you wake up at night
and you look over at your digital alarm clock or some small,
bright light in your room, and the thing
starts jumping around? That is the autokinetic effect. The room is
dark, there's a point source of light, and you're fixating on it;
there are no reference points against which your brain can correct for those
tiny movements of your eye. Consequently, it just kicks back and believes what you see.
This, I'm told, is the reason that running lights on airplanes blink -- to discourage fixation. The
effect has also been put to good use by a social psychologist named Muzafer
Sherif, who used it in a classic study of conformity and
persuasion.
Sources:
Dr. Jack Feldman's PSYCH 2210 class at Georgia Tech
http://www.cis.rit.edu/people/faculty/montag/vandplite/pages/chap_13/ch13p2.html
http://www.aoanet.org/clincare/aviation-night.asp