The original title on the website does not do much to reveal the content, but in short, the book is about a new "theory of the brain" (new as in the past 10 years), based on predictive processing.<p>The post itself, and the follow-up posts about predictive processing on the above blog are probably the easiest way to get into the subject, and it's an insanely interesting subject.<p>The core of the idea is written a bit into the blogpost: "The key insight: the brain is a multi-layer prediction machine. All neural processing consists of two streams: a bottom-up stream of sense data, and a top-down stream of predictions. These streams interface at each level of processing, comparing themselves to each other and adjusting themselves as necessary."<p>Deeper into the post, there's a breakdown of how this theory fits into various areas of research in novel ways (autism and schizophrenia among them), and I strongly suggest reading through at least that.