Although it's not what's asked for here, my professional opinion as a professional (ancient) historian is that psychoanalysis and Freud need to be put away for now - and possibly for ever - as something that just allows old white men to oversexualise the world around them.¹ Putting historical figures, or artists, or paintings, through the Diagnostic and Statistical Manual of Mental Disorders (though not, of course, what is strictly being done here) can never produce meaningful results, beyond 'if x were true then y might follow'. And so, I read Foster's chapter on psychoanalysis with the rigour and passion it deserves.
My first thoughts on this chapter are: here is an excellent example of how not to write a theory and methods chapter. Not only does Foster not adequately introduce his subject matter, he gives no real contextual information and burdens the viewer with a significant amount of unexplained jargon. But that aside: the content. When I mark essays from my own students I rarely give them more than a second read - if I cannot understand what you mean after reading a sentence twice then I give up on it.
In parts of this chapter, it appears as though Foster wants to attribute a higher level of influence than psychoanalysis has actually attained within the use of practising artists. The Surrealists' affinity for Freud's concepts of dreamscapes and 'insanity' (and rightly or wrong, by extension with primitivism - an idea that was not confined to art²). And this is a relationship that is strained both ways - between art and psychoanalysts and between artists and psychoanalysis³), so it's hard to take psychoanalysis seriously as a methodological approach to art or art-making.
Foster mentions, but plays down, the fact that Freud's psychoanalytic theories were based on highly flawed analyses of manipulated patients. In addition to that he asks what I personally consider something of a moot questions: 'who or what is to occupy the position of the patient - the work, the artist, the viewer, the critic, or some combination or relay of all these'. The patient is always the thing being 'decoded', which means it is always the work(s) (that may seem a relatively rigid position to take, but I think a fairly clear one). It should never be the artist, though probably sometimes is. It is obviously never the critic, viewer, or historian, who takes the position of the analyst. Foster himself goes on to put forward and equally reductive mode of interpretation in the pages that follow.
Perhaps my role as a student is here hampered by my role as an academic, and the role that psychoanalysis has played in my own field (after all, we're the ones who have Oidipous!).
¹ I realise this may sound unfair, and perhaps is in some disciplines, but as an ancient historian I feel that it adequately represents that types of people who utilise psychoanalytical approaches in any kind of serious way.
² See, for one example, the publication of Aldous Huxley's Brave New World in 1932, which showcases social eroticisms of the primitive man trope.
³ and cf. Esman, AH (2011) “Psychoanalysis and Surrealism: André Breton and Sigmund Freud.” Journal of the American Psychoanalytic Association 59.1: 173-181.
⁴ Foster 2012: 18.