I think there are some confusions here about the mind's eye, and the way the visual cortex works.
First of all, I suggest you do the selective attention test. Here will do. Selective attention test
This video illustrates the difference between looking at a scene and actually seeing it. Do pay attention closely or you might miss something important!
The bottom line is that when you look at the outside world, thinking that you see it, your brain is converting the external world of light images into an internal coding of that image. It cheats, royally, when it tells you that you're seeing the world as it is. You're perceiving a coded version of it, and that code is actually optimised for usefulness and the ability to respond quickly. It's not optimised for completeness - it's more about enabling you to pay attention to one main thing, and ignore everything else in your visual field that doesn't currently matter.
And that's where your comparisons later fall down. The computers rendering Avatar have to create images of the fictional world. Your own internal mind's eye doesn't have to do that - it only has to generate codes that stand for visual scenes. Where Avatar's computers had to render the dragon pixel by pixel, your internal eye only has to create a suitable symbol standing for "Dragon in visual field, dead centre." It doesn't bother to create nearly all of the rest of your imagined world in the same way as some people ignore the important thing in the attention test. Because you only EVER see the coded versions of the world, the two look the same to you. But it is a much cheaper operation as it's working on small groups of codes, not millions of pixels.
The human brain is a very nice machine - but I also suspect it's not as fast as many people think it is. Time will tell.
From time to time I encounter people who claim that our brains are really slow compared to even an average laptop computer and can't process big numbers.
At the risk of revealing my complete lack of knowledge of neural networks and how the brain works, I want to ask if this is actually true?
It took massive amounts of number crunching to create movies like James Cameron's Avatar. Yet I am able to create more realistic and genuine worlds in front of my minds eye, on the fly. I can even simulate other agents. For example, I can easily simulate sexual intercourse between me and another human. Which includes tactile and olfactory information.
I am further able to run real-time egocentric world-simulations to extrapolate and predict the behavior of physical systems and other agents. You can do that too. Having a discussion or playing football are two examples.
Yet any computer can outperform me at simple calculations.
But it seems to me, maybe naively so, that most of my human abilities involve massive amounts of number crunching that no desktop computer could do.
So what's the difference? Can someone point me to some digestible material that I can read up on to dissolve possible confusions I have with respect to my question?