Class Warfare Blog

October 4, 2019

More on the “Reality” of Our Senses

Filed under: Science — Steve Ruis @ 12:45 pm
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A recent magazine article in Quanta magazine addressed some fine points most of us are unaware of regarding our vision (Your Brain Chooses What to Let You See, <sub> Beneath our awareness, the brain lets certain kinds of stimuli automatically capture our attention by lowering the priority of the rest.).”

There are a number of fascinating limitations on our ability to “see,” that is to take in information through our eyes and process it. Consider these snippets from the article:

“Scientists have long known that our sensory processing must automatically screen out extraneous inputs — otherwise, we couldn’t experience the world as we do. When we look at our surroundings, for instance, our perceived field of view holds steady or moves smoothly with our gaze. But the eye is also constantly making small movements, or saccades; our visual system has to subtract that background jitter from what we see.

“Automatic suppressive types of mechanisms take place … through large swaths of the brain,” said Richard Krauzlis, a neuroscientist at the National Eye Institute at the National Institutes of Health in Maryland. “Basically all over the place.”

“And automatic background subtraction, it turns out, can also manifest in intriguing, unexpected ways. Take a counterintuitive finding that Tadin and his colleagues made in 2003: We’re good at perceiving the movements of small objects, but if those objects are simply made bigger, we find it much more difficult to detect their motion.”

What a lot of people don’t realize is that the sheer amount of information available to our senses would swamp any brain, supercomputer, quantum computer, you name it. So, we necessarily must dump a very high percentage of the information (bits and bytes) coming in because we have neither a way to store it nor process it. (Read the book The User Illusion by Tor Norretranders if you are interested in this topic.)

Apparently there are many, many mechanisms used to sort and prune away superfluous information. One of those is that our eyes actually have a very small cone of focus (<10°) in which our vision is sharp and detailed. Visual acuity declines by about 50% every 2.5° from the center up to 30°, at which point visual acuity declines more steeply. Consequently, our visual sense flits about, usually caused by something moving. Our attention brings the moving thing center stage where we can see it clearly. This is why TV screens in a bar or another room keep pulling on our attention. The flashing lights simulate things moving, so our eyes flick there . . . over and over and over.

The light entering our eyes, as I have mentioned, is taking 3-D information and projecting it upon a 2-D surface (the retina) losing the information from the 3rd dimension. Well, and the optics of the eye flip the images upside down and . . . and . . . well, suffice it to say, a fair amount of “post capture” video processing needs to occur.

I recommend the article to you if you are interested in how our senses do not (and really, cannot) detect “reality.” And, those who are alarmed at how much our senses fail to detect “reality,’ well, I think they doth protest too much.

Our senses can be trusted to be what they are. In that they are quite trustworthy . . . flawed but trustworthy. And just because we are not immediately aware of what is going on, that doesn’t prevent us from actually learning what is going on, so as to appreciate it for what it is and not just what we think it is.

 

September 18, 2019

More on Senses (Can We Trust Them?)

Filed under: Philosophy,Reason,Science — Steve Ruis @ 11:35 am
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This topic struck a nerve, to some extent, And, it may be a manifestation of “the green car effect” but having written recently about whether we can trust our senses, I ran across the following book. Here are the title, author, and Amazon.com’s blurb for that book:

The Case Against Reality: Why Evolution Hid the Truth from Our Eyes by Donald Hoffman

Can we trust our senses to tell us the truth?

Challenging leading scientific theories that claim that our senses report back objective reality, cognitive scientist Donald Hoffman argues that while we should take our perceptions seriously, we should not take them literally. How can it be possible that the world we see is not objective reality? And how can our senses be useful if they are not communicating the truth? Hoffman grapples with these questions and more over the course of this eye-opening work.

Ever since Homo sapiens has walked the earth, natural selection has favored perception that hides the truth and guides us toward useful action, shaping our senses to keep us alive and reproducing. We observe a speeding car and do not walk in front of it; we see mold growing on bread and do not eat it. These impressions, though, are not objective reality. Just like a file icon on a desktop screen is a useful symbol rather than a genuine representation of what a computer file looks like, the objects we see every day are merely icons, allowing us to navigate the world safely and with ease.

The real-world implications for this discovery are huge. From examining why fashion designers create clothes that give the illusion of a more “attractive” body shape to studying how companies use color to elicit specific emotions in consumers, and even dismantling the very notion that spacetime is objective reality, The Case Against Reality dares us to question everything we thought we knew about the world we see.

It’s a frickin’ conspiracy that is what it is!

Uh, no. I have not read this book and probably will not and while the author may not have written the blurb but there are a number of things disturbing about it. For one “Challenging leading scientific theories that claim that our senses report back objective reality . . .” WTF? What “leading scientific theories” are these? I am aware of none of these. The literature on optical illusions goes back a couple of millennia at least, so I don’t think anyone was going to make such a claim in the face of those. And just what the heck is objective reality? Philosophers talk about such things, but scientists? Scientists are forever devising replacements for our senses to expand our observation capabilities. Why would they be looking for those if our senses were thought to portray “objective reality” all by themselves?

“Ever since Homo sapiens has walked the earth, natural selection has favored perception that hides the truth and guides us toward useful action, shaping our senses to keep us alive and reproducing.” If you take “hides the truth and” out, this is quite correct. But scientists aren’t interested in truth, not even a little bit. And evolution did nothing to hide anything, certainly not “the truth.” Anything that did happen that increased our reproductive success was kept and anything that did not was not. It was not about perfecting one’s senses or hiding the truth or whatever. This is deceptive use of language, making evolution out to be a villain which is “hiding the truth,” the truth of a revealed god, perhaps?

“The real-world implications for this discovery are huge.” No they are not. Don’t be silly. We have known much of this for quite some time. Have you noticed people going crazy in the streets? The stock market in turmoil? (Check that, the stock market is always in turmoil.) Animals retreating into the hills? Babies crying continuously?

People, this is all quite simple. All animals perceive the world around them. This is a requirement for the ability to move. All of these perceptions are limited. Eagles have much better visual acuity than do humans. So effing what? Whatever our visual acuity is, it will not be perfect. Our ability to distinguish different pitches of sound provides us with the ability to communicate vocally. But bats and dolphins hear quite different kinds of sounds. So what? Whatever that ability, it will be limited by the mechanism used to transmit the physical stimulus (compressed waves in the air) into signals our brains can deal with. We cannot hear high pitched sounds and very low pitched sounds, but other animals can. BFD. None are perfect.

And for every sense we have, our brain has to come up with some kind of system to codify them, just as we do socially. (We have an Orange Alert for Southern California! Shoppers we have a Grocery Department Special on Aisle 7!)

There is no real or imagined sensory input system that reveals whatever the heck objective reality is. So, yes, reality is a matter of opinion. We spend a great deal of time interacting with other people and sharing our realities, only to find ourselves perplexed as to how some people just can’t see the truth right in front of their faces. This also is why we have so many people who believe imaginary supernatural beings and events are “real.” If their reality were not subjective, would they still be able to cling to their fantasies?

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