[lisper]

I think you're missing something really fundamental. Decoherence happens at the sub-microscopic level -- unless things are very, very cold, in which case you can get macroscopic quantum effects. But at room temperature, by the time you get up to the molecular level things are already more-or-less classical. By the time you get to the level of a neuron they are (as far as we know) indistinguishable from classical. From the point of view of QM, there is no difference between being asleep and being awake. All of your mental processes are indistinguishable from classical.

[dingbat]

yes i understand decoherence at different scales, but my point is that the Arrow of Time exists for both a real physical object, such as someone falling off a cliff, but also a non-real object, such as someone dreaming of falling off a cliff. decoherence can explain the first, but since there is no physical cliff or object in a dream (at either the micro- or macro- scale), how can it explain Arrow of Time that is observed in interactions between non-physical imaginary objects?

[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".