There's one point i've read somewhere that really made methink differently on this subject: It was claiming that listening to lossy formats will increase brain activity, because you're brain makes up for some missing information on thy fly. This is not a conscious proccess. But after listening to music for a while, lossless music could be less exhausting and more relaxing because of that.

Not completely sure, if this is true, I couldn't find the study for it right away.