The perceptual model of introspection (PMI) is pretty much hand-waived away currently. Gregg Ten Elshof tries to show that there are no good arguments against PMI that consider PMI as an interesting theory in itself, as opposed to arguments from philosophy of mind (like how functionalism appears to rule out PMI).

This book is very clearly argued, and supposing he has fairly represented Shoemaker, Lyons, Dennett, and Searle, I think he's shown their arguments against PMI aren't so hot (though at least Shoemaker and Lyons disagree, and probably Dennett too). A couple places where the book could have been improved are in the section on the history of PMI and in the section that seeks to develop PMI in more depth. The history of the view is a bit quick, leaving questions about Brentano unanswered in the book, for instance. The last chapter basically raises more questions than it answers. So, his book is a defense of the perceptual model as opposed to a development of it (but we already know that from the title). Otherwise, a very good book if you can get over the hump that all Ashgate books have: a ridiculous price.