A problem with psychiatry didactics, at least where I did residency, is I've noticed that several of the residents were either trying to catch up on sleep or simply focused on passing USMLE step III. On the one hand, who could blame them? When you lack sleep, you're going to try to catch up on that first before you start caring about much else. As for Step III, the reality of possibly failing it looms over the psychiatry resident's head much heavier than reading up on things such as Tukey's honest significance test or Bayesian theory, neither of which will be tested on USMLE Step III but are cornerstones in the behvioral sciences.
Attendings often graded residents on their practicality and efficiency at clinical work. While those are very important, they often times did not give a hoot about their mastery of the behavioral sciences. Who cares if the resident doesn't know Beck's triad of depression? They know how to admit and discharge the patients well enough for the attending to get home before the rush hour traffic.
IMHO, it'd be nice if residency were more like getting a master's degree where people are focused on doing well in classes where they are graded, instead of having lectures where several of the residents are half asleep from the previous night's call, or didn't even have to go to lecture because of call.
While I was a resident, and where I did it, most of the residents did not take Step III until PGY III or IV. For that reason, very few of the residents were focused on psychiatry other than getting through the day in clinical work. Most of residents for that reason were more focused on studying internal medicine instead of psychiatry.
But enough of my rant.
If you are a PGY I, get step III out of the way if you haven't. That way you can then focus on psychiatry for real. The best initial steps from there, IMHO, is to study for the written psychiatry boards, not just for the sake of passing it but for the sake of learning psychiatry for real. If you can pass step III by PGY I or II, you'll have plenty of time to focus on psychiatry for the sake of it.
Get some books to study for the board exam. Several have been suggested on this board. Some include the Stahl books on psychopharmacology, Kaufman's Neurology, the MGH board prep book, etc. Some of the board prep material I've come across does cover learning theory to some degree though in a much more simplistic method compared to that often seen in psychology. I don't know if that'd be enough to satisfy your curiosity.
If you want to study some psychology texts, IMHO the best too look at on the easier level is a good on covering Abnormal Psychology. If you want to start getting hardcore, I'd recommend behavioral endocrinology, developmental psychobiology, or a highly respected book on psychotherapy. IMHO if you could master the latter books, you're on your way to becoming a real psychiatrist, not just a monkey that knows how to put a square peg into a square hole and a round peg in a round hole (antidepressant for depression, antipsychotic for psychosis).
If you really want to push it, start mastering one of the related sciences that complements psychiatry. My fellowship PD mastered statistics to the point where he actually advanced the field of it in application of the medical sciences and predicting future violence.
Getting onto learning theory, perhaps some of our psychology colleagues could assist you since I have not picked up any recent psychology texts. I can tell you that in clinical practice, conditioning is very important especially with substance disorders. Reward schedules are very important in inpatient facilities.
I'll ask my wife to recommend some texts because she is currently in a Ph.D. counseling program. She won't be back for a few days.