Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: alexbalex on 23/07/2015 22:08:03
-
Hi,
In conversations about things in life one is encountering all sorts of people with different views and when it comes to phenomena like dreams, drug effects, hallucinations etc, everyone has some kind of an explanation. Religion, spirituality, aliens, you name it. As someone who relies on science to construct my views I'm often using terms like "most likely ", "we don't know " and "either/or", which is up against someone's 100% bulletproof biases. Lately I have developed a narrative about how brain works that is bringing me some success in this discussions. Here it is:
The brain is a virtual reality machine. Sensors are not providing the brain with uninterrupted stream of information about the surrounding environment but only bits. For example the eye is transiting 3 impulses in 1 seconds. What happens is that the brain is filing the gaps so we perceive the world as constant flow. If every moment of time there was a real sensory input, the brain wouldn't be able to process it. It is more economical for the brain to create virtual reality. Still this virtual reality is being constructed around the scaffold (or skeleton) of real sensory information about the real world. Sensors are the anchors that keep us constantly linked with the reality. But what happens when sensors are shut down but brain is still working. Then it produces a virtual reality without the sensory input to keep it in check and all sorts of things become possible. The dreams when we sleep, the hallucinations when high, the experiences during religious trance, near death experience, all that seems to be explained. I made it sound simplistic and I am aware that consciousness is incredibly complex. The bottom line is that if you influence the relationship between sensory input and virtual reality construction weird things can happen.
Please comment on this. Thanks.
-
... the eye is transiting 3 impulses in 1 seconds ...
Human vision can perceive images faster than that : flicker-fusion-threshold is at least 15 per second ... https://en.wikipedia.org/wiki/Flicker_fusion_threshold
... If every moment of time there was a real sensory input, the brain wouldn't be able to process it. It is more economical for the brain to create virtual reality. Still this virtual reality is being constructed around the scaffold (or skeleton) of real sensory information about the real world.
The brain doesn't experience reality, it experiences input from the senses. Whilst awake the brain is always creating a [virtual] model of reality (https://en.wikipedia.org/wiki/Umwelt#Discussion) , which isn't completely accurate . Optical illusions are an example of the brain's model of reality being revealed as conspicuously inaccurate ...
[ Invalid Attachment ]
-
My comment is this.
What a damned shame it is that "educated" people leave school nowadays apparently never having heard of Socrates' "Allegory of the Cave". The perspicacity of Socrates is born out in the current debate about whether Quantum Mechanics thru Heisenberg's uncertainty principle rightly questions the existence of reality.
Einstein famously tried to put down QM by asking, "Is the moon not there when I don't look at it?"
If you happened to watch Professor Jim Al-Kahlili OBE in his recent documentary on BBC4, "The Secrets of Quantum Mechanics" (1.) nobody would blame you for wondering if Einstein "didna hae his bum oot the windae" about that.
So if Einstein couldn't nail down the nature of reality, what chance have we to do it here? After all, the majority of the universe consists of unknown dark matter and we are here as on a darkling plain swept with confused alarms where ignorant armies clash by night.
(1.)
-
My brain suggests to me that the perceptions of reality that our brain does or does not accurately form, and questions as to reality associated with the quantum uncertainty principle, are quite different questions.
Of course, that would not apply if the brain were a quantum computer, but what we currently know of it suggests otherwise.
-
As to the original subject, how does our brain figure out reality?, I don't think we really understand that fully, but your opinions may be substantially correct, at least speaking generally. Keep also in mind that much of what we understand of what we are currently experiencing is interpreted through pre-existing knowledge. That is very helpful in making sense out of things, but can also mislead us if perchance we encounter something that we think we recognize but that does not follow the rules that we have previously learned.
-
A somewhat different question has to do with the ability to immediately form a correct interpretation of a present stimulus so that its essential features are operationally understood. For example, observing while driving that there is a pedestrian standing in the road and that application of the brakes is highly advisable. To do that, it is necessary first of all that the image received by the eyes be correctly understood, at least to the extent of the immediate problem. It is indeed not a trivial question, in general, to ask how that is done. The difficulty of dealing with such a question becomes more evident when one attempts to create a self-driving vehicle. Then one must directly confront the issue of taking the image from video cameras and making operational sense out of them. To understand the matter, it might be profitable to read material dealing with such computational problems. The software solutions found therein will at least suggest the shape of the problem, but may not necessarily give correct insight into how the human brain does it, because the human brain is a quite different machine than a digital computer.
-
In the driverless car problem, it is evident that the first process that must be performed, assuming we are using binocular vision as the technology (as distinct from radar etc), is to take two images and from them make a three dimensional map of the environment. By what process can this be done? Each image is composed of features, which are defined by discontinuities between zones of more or less uniform color. In the two images, the positions of the discontinuities are determined by the horizontal and vertical displacements from some axes of reference and by the distance from the camera, but also by the parallax correction associated with the position of each camera with respect to their mean position. The parallax will show up as the difference in the distance of a given feature (from the image reference origin, e.g. center of the frame) as seen in one image compared to as seen in the other. On the basis of that, we could go through the image, feature by feature, measuring this difference for each, and then construct a new image having three dimensions in which the horizontal and vertical positions of each feature would simply be the mean of those in the source images, but the radial displacement (third dimension) would be determined by the differences in their imaged positions. Of course, that derived image gives not the entire 3-D picture of the situation, but only of as much of it as can be seen from the direction of view. To fill in the rest, assumptions would have to be made. They could be made on the basis of prior experience, or they could be simply made on the basis of a simple default formula, in which the unknown parts of the scene, behind that which is visible, is simply treated as being filled in with a featureless nondescript dummy substance. This assumption may be adequate for many purposes in which we do not really need to know the precise nature of the full object, but only what the object is and where it is. Thus, to brake upon detecting a pedestrian in the roadway does not require that we formulate an accurate guess as to the nature of his or her haircut on the side that we cannot see, and it is a waste of processing time to try.
One problem with this approach is that some features such as horizontal long items cannot be pinpointed radially using parallax between cameras separated from each other horizontally. In such situations, further guessing is required. Such guessing can be performed by looking at the endpoints of the feature, which are likely to be associated with some other features that can be accurately located radially, and then assume that they connect. Thus, the top and bottom edges of a doorframe would be assumed to be located at the same distance away as the sideposts. Another method is to look for fine detail associated with the horizontal feature, such as insects crawling upon it, and on the basis of their distance away, assume that the horizontal feature is also the same distance away. Another method is simply prior experience: a horizontal power line whose supports are out of view would be simply assumed to be located at about the distance where power lines of the viewed elevation typically are located. It will be noted, of course, that in all of this, a lot of assumptions and guesswork come into play, and in view of the way the human mind can be fooled by optical illusions, it would seem that the human mind does in fact indulge in such behavior as an important part of how it generates a perception.
-
So, Atomic-S, I think you are trying to tell me that in your weltanschauung the mind is separate than the physical universe and therefore the implications of quantum mechanics on cause and effect are trivial and moot.
That is very reassuring. Socrates would have listened to that and - recalling the allegory of the cave - given me a wink.