Is attention a non-propositional attitude?

The investigation of attention has been pursued in a surprising disconnect from the investigation of other aspects of the mind. Much of the philosophical discussion of perception, belief, desire, intention, imagination or emotion, for example, revolves around issues of intentionality and content. Versions of the following questions will, thus, sound familiar to many philosophers: is perception an intentional state or is it fundamentally relational? Does perception have intentional content? If so, how is that content structured? Is it, for example, propositional? And is it conceptual or nonconceptual? In contrast to the sophisticated and detailed treatment of these and related questions in the philosophy of perception (and similarly for the other mental states) the discussion of the corresponding questions about attention whether it is, for example, intentional, propositional, or non-conceptual – insofar as it exists at all, has been mostly confined to casual side notes.