I think that the "Drawing the negative space" concept the Paul talks about in the book is different that the physiological effect in that link.
I believe that Paul is trying to get you to consider the white spaces on the page and not the black text. This is similar negative space drawing technique. You are directing your conscious mind around the matter of interest. You are still completely aware of it, but your mind doesn't fixate on any details of the object of interest.
I've done this in drawing classes and it takes awhile, but it is very useful.
It's the same as his saying "see the white spaces" on the page. It helps to stop the conscious mind from hard focussing on individual words.
The believe the effect you see in the image is a fatigue or persistence issue. It is not the blip page (parallel vision) effect.
You are perfection.
Iam2 