April Fools' Day, 1 April 2002: This column is finished and awaiting upload to SAS web site. I had discussed it last month with Christoph von der Malsburg, who soon afterward read Erwin Schrodinger (1958) Mind and Matter and today sent me its pages 132-33. they relate essentially the same experiment  as described (for different purpose) by Sherrington in Man on His Nature (1940) p. 273. However his example has 30 Hz flicker alternating in each eye plainly perceived as such (this being 60 Hz centrally) even though 60 Hz is beyond flicker fusion in either eye. To my mind this "Sherrington's paradox" is at least verbally dispelled by supposing flicker fusion a phenomenon of the retina, while cells beyond there are capable of higher rates.  (It is also of interest, at least to me, that I read Mind and Matter with keen interest as an undergraduate and at least once afterward, pretty much completely forgetting its contents between readings: it is probably the unconscious source of "my" idea for the alternating flicker experiment.)
 

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