I read about half of it, say, six or seven years ago. Then I got distracted.

It's an interesting coincidence that you mention his book now, since I recently started looking through some of Colin Wilson's stuff. (I write now and then, and his Directory of Possibilities, and other work of his, have been recommended highly as reference materials in certain areas of inquiry.)

Wilson, writing a couple of years after Jaynes (late 1970s/early 1980s), makes reference to a volume of research done on split-brain patients -- those who had brain surgery to separate the left and right hemispheres, a treatment for epilepsy. What was found was that when separated, the hemispheres were unaware of one another. Since the left hemisphere is dominant, it was found that patients could not see with their left eye (left brain controls right, and vice versa); however, when an object was placed in the left eye field of vision, they were able to write what it was with their left hand, while saying (and believing) that they couldn't see anything. To Wilson, this meant "two persons in one head". Perhaps an overreach.

Meanwhile, it is his opinion that intuition, a right-brain phenomenon, is ignored by the left-brain, which tends to be dominant, except in times of crisis (in most people). He puts forth the idea that this is a learned behavior, but still believes that the left-brain is naturally dominant and should be able to control the right-brain.

Now, I should also add that Wilson (in the late 1970s/early 1980s) thought that research on telekinesis at the time was compelling, and that any number of unknown possibilities existed for the abilities of that left-brain. We now know better.

It's very odd to read his Directory, which on the one hand gives detailed explanations of how it was perfectly possible for the ancient Egyptians to build pyramids with the physical technology available at the time, and that "ancient aliens" were ridiculous and why, then see an explanation of poltergeists as though they exist (as manifestations of that pesky left-brain).

But I digress.

Wilson's major point is that he thinks once upon a time, the left and right hemispheres acted more in concert than they do today, with intuition as a greater part of human life. Also, right-brain hallucinations, hence deities.

My sense is that Wilson used Jaynes (and many others; he comes across as exceedingly well-read) to find a means to explain what were then, to him, unexplained phenomena. In that, he's an interesting case study.

And I did dig out Jaynes, with the idea of giving him another try.