Eventually, I realized. The neat, printed-book paragraphs were clear, correct, and complete. The untidy-looking, seemingly badly-typed ones—despite identical objective appearance—always turned out not to be: their content was either confused, incorrect, or incomplete in some way. And amazingly it was sometimes only weeks, months, or even years later that I realized what was wrong with these messy heaps of words.

At first sight, this looks like a persuasive proof of the unconscious: as if I must have known what was wrong unconsciously. Indeed, it even suggests pre-cognition or clairvoyance, because sometimes there was just no way I could have known what was wrong at the time. 

Nevertheless, I now realize that there is no reason to resort to such hyper-mentalism. In fact, a mechanistic explanation is much more likely which suggests these experiences to have been the product of a kind of synesthesia.

This term describes sensations in which normally separated modes of perception overlap or interfere. As with so much else in modern cognitive science, it was first described by Galton, and the incidence is said to be about 1 in 2000. Synesthesia is more common in women, and there are at least 20 different forms, the most common being colors linked to letters, numbers, or words. For example, the novelist, Vladimir Nabokov (1899-1977) had "colored hearing": b was burnt sienna, and s was "a mixture of azure and mother-of-pearl."

Nor is the effect imaginary: in a 1993 study, synesthetes were 92 percent consistent in linking particular colors to sounds after oen year, but non-synesthetes could manage only 37 percent after one week. Furthermore, the effect is not always agreeable. The inventor, Nicolas Tesla (1856-1943), tasted the flavor of certain sights: small squares of paper seen in a dish of liquid would fill his mouth with a horrible taste!

Precedents like this suggest to me that perhaps the messy-words effect was a minor form of the same thing in which one type of perception—the esthetic appearance of my text—was being influenced by a completely different form of cognition: that relating to its meaning and content. After all, both are involved in reading. First you have to treat the text as a visual perception and read the words, and then you have to perceive what they mean.

Complete, correct, and clear verbal expressions almost certainly trigger fewer cerebral circuits than incomplete, incorrect and unclear ones in just the same way that we now know that telling the truth uses less brain capacity than telling lies. It may be that, somehow or other, I have a sense of the level of brain activity involved in what I am reading, and this interferes with my visual perception of my words, making them seem neat if the level is low but messy if it is high.

Finally—and conclusively in my view—there is one further consideration which makes this overwhelmingly likely: foot-fetishism.

Once upon a time, foot-fetishism looked like a paradigm for the libido theory. It vindicated it in three key respects: First, foot-fetishism was a classic sexual perversion. Second, the foot had absolutely nothing to do with the genitals or with reproduction. Finally, it seemed obvious that any connection between foot and sexuality had to originate in the unconscious—plausibly in the polymorphous perversity of childhood.

Today we know the truth: as the diagram below shows, it is simply that the sensory circuits in the cortex wired to the genitals lie next to those wired to the toes and foot. This creates the opportunity for overlap and cross-talk which manifests itself as sexual excitation associated with the feet. Indeed, foot-amputees report much bigger sensations of orgasm when they are no longer confined to the genitals but have migrated to the phantom foot! And as the diagram also shows, this is because the toes and feet have a bigger mapping than the genitals. 

Foot-fetishism, in other words, has nothing whatsoever to do with the unconscious or with a person's repressed polymorphous-perverse libido. It has everything to do with the way their brain is wired up. Indeed, I now believe this to be generally true. The concept of hyper-mentalism made me realize that psychoanalysis had institutionalized this pathological extension of normal mind-reading in its attempt to find psychological meaning in anything and everything. But there is no deep, repressed, or unconscious meaning in foot-fetishism—just brain anatomy surfacing as subjective sensation.

And I now believe that the same applies to my visual/conceptual synesthesia: it is a very useful subjective sensation mirroring the activity of my cortex overall and has now become an indispensible part of preparing these posts. Only when they look completely right do I know that they are right. And this one does!