Hey. I think most people enjoy dreaming. Unless they wake up in an anxious or fearful state. Sometimes I feel a bit disturbed waking up after a dream. Most of the time I enjoy what I manage to recollect of them, however.

I'm not sure if fMRI's have been used to scan someone while they are dreaming. I've never had an fMRI before... I'm not sure what the machines are like... It might be hard to scan someone while they are asleep. If the machines are very chlaustraphobic or if they make a noise etc. There are other kinds of neural imaging, though, I'm not sure what neural images have been done. I guess they have done stuff with external electrodes. There is stuff on different levels of sleep (REM or dreaming vs deep sleep etc).

I would be dubious about fMRI's being a litmus test for truth telling vs lying... I'd be dubious about it being a litmus test for homosexuality or sociopathy etc too. I'm fairly dubious about the utility of neuroimaging in general, however...

How do you think a fMRI scan would prove or disprove Freud?

I think that there is no evidence for the dynamic unconscious (the state that creates the dreams and hides the content under layers of symbolism). There has been quite a lot written on how cognitive psychology now talks about unconscious processes and hence Freud has been vindicated, but that isn't quite right. The unconscious processes that cognitive psychologists talk about are mechanical processes that occur pre-consciously (e.g., processing prior to conscious awareness like visual edge detection) or unconsciously (e.g., the processes involved in regulating your temperature). Those processes aren't 'intentional' or 'dynamic' (they don't 'choose' or 'hide' anything at all). So seems like Freud was wrong about the dynamic unconscious (the mental mechanism that produces dreams). But that is if he means it literally in the sense that there is such a mental structure that causes one to have the dreams that one does have. If one is looking for meaning... The way one interprets the meaning of tea leaves or rorscarch tests or horroscopes or configurations of planets or rune stones etc etc... Can say a lot about you. But that isn't to say that any of that stuff has meaning independently of what we project onto it in hindsight.

We don't know very much about dreaming... But we know that animals seem to dream (they have brain patterns similar to us when we are in REM sleep and they make motor movements and if you remove the paralysis that normally accompanies REM sleep they will 'act out' their dreams of hunting mice or whatever). If people don't get REM sleep they tend to get psychotic... So it does seem to be a necessary function... One thought is that it is the brain processing stuff that happened during the day so as to facilitate storage etc. Kind of like... A neural defragment. Kind of keeping the files in order. That would explain why things that we have seen or themes that have occured to us often occur in our dreams.

Perhaps...