[lisper]

But your perceptions of real and non-real objects (and hence your perception of time) comes from the same source: the pattern of neurons firing in your brain. It ultimately doesn't matter whether those neuron firings are caused by external stimuli from real objects or internal stimuli from imaginary ones. The nest result is the same: your perception of the passage of time runs in one direction because your mental states form a totally ordered sequence of accreting memories. Decoherence insures that those memories remain self-consistent with each other and with the "real world".