Mental imagery as non-physical experience

[AgnosticBoy]

On another thread, I argued that mental imagery is nonphysical in that it lacks physical characteristics. Some materialists disagreed offering nothing more than a future promise that we'll discover how they're "purely physical". Here's one description of a type of mental imagery:

A hallucination is a perception in the absence of external stimulus that has qualities of real perception. Hallucinations are vivid, substantial, and are perceived to be located in external objective space. They are distinguishable from these related phenomena: dreaming, which does not involve wakefulness; illusion, which involves distorted or misinterpreted real perception; imagery, which does not mimic real perception and is under voluntary control; and pseudohallucination, which does not mimic real perception, but is not under voluntary control.[1] Hallucinations also differ from "delusional perceptions", in which a correctly sensed and interpreted stimulus (i.e., a real perception) is given some additional (and typically absurd) significance.

Hallucinations can occur in any sensory modality—visual, auditory, olfactory, gustatory, tactile, proprioceptive, equilibrioceptive, nociceptive, thermoceptive and chronoceptive

Source: https://en.wikipedia.org/wiki/Hallucination

My view is that the perception of mental images constitutes an experience of something non-physical. For those who think otherwise, please do the following:

Explain how or why the experience of hallucinations is physical or of something physical.

[Divine Insight]

You've failed to show how electrical activity gives rise to images when NO screen or other physical medium exist to actually view mental images. NO computer does this!

ALL computers do this!

Apparently that's your problem right there. You simply don't understand how it's done.

When a digital camera takes a photo and stores it on a memory card, there is no "image" of the object on the memory card. All that exists on the memory card are bits of information that can then later be reconstructed to reproduce the original image.

Moreover the digital information stored on the memory card truly has nothing at all to do with the image it has "recorded". In other words, if you didn't know the specific algorithm that the camera used to create this digital representation of the image you could not reconstruct it. Different manufactures of digital cameras and computer may actually use different algorithms to store images. Therefore the digital information stored on their memory cards will be different for the same image.

So the information stored on the memory card really has nothing at all to do with the original actual image other than the connection made by the specific algorithm that was used to create and store the digital information.

So there are no physical images stored in your computer at all. All that exists are bits of 1's and 0's that can be reconstructed by the computer via a specific algorithm and then displayed on a screen that is also compatible with this specific algorithm.

No images exist inside your computer. However there is physical information being stored in the computer that can recreate the images.

Our brains no doubt work in a similar way only they use analog processes instead of digital algorithms.

So our brains are doing precisely the same sort of thing that computers are doing. The only difference is that our brains use analog techniques while computers use digital techniques.

In this way there are no 'images' in your brain at all. All that exists inside your brain are electrical patterns that the brain can experience as "images". That doesn't mean that those electrical patterns need to "look" anything like the images at all.

So for you to claim that no computer does this is false. That's precisely how all computers work. And there's no reason to think that a human brain doesn't work in a very similar fashion save for using analog methods instead of digital methods. That would be the only difference.

[AgnosticBoy]

You've failed to show how electrical activity gives rise to images when NO screen or other physical medium exist to actually view mental images. NO computer does this!

ALL computers do this!

Apparently that's your problem right there. You simply don't understand how it's done.

When a digital camera takes a photo and stores it on a memory card, there is no "image" of the object on the memory card. All that exists on the memory card are bits of information that can then later be reconstructed to reproduce the original image.

Moreover the digital information stored on the memory card truly has nothing at all to do with the image it has "recorded". In other words, if you didn't know the specific algorithm that the camera used to create this digital representation of the image you could not reconstruct it. Different manufactures of digital cameras and computer may actually use different algorithms to store images. Therefore the digital information stored on their memory cards will be different for the same image.

So the information stored on the memory card really has nothing at all to do with the original actual image other than the connection made by the specific algorithm that was used to create and store the digital information.

So there are no physical images stored in your computer at all. All that exists are bits of 1's and 0's that can be reconstructed by the computer via a specific algorithm and then displayed on a screen that is also compatible with this specific algorithm.

No images exist inside your computer. However there is physical information being stored in the computer that can recreate the images.

Our brains no doubt work in a similar way only they use analog processes instead of digital algorithms.

So our brains are doing precisely the same sort of thing that computers are doing. The only difference is that our brains use analog techniques while computers use digital techniques.

In this way there are no 'images' in your brain at all. All that exists inside your brain are electrical patterns that the brain can experience as "images". That doesn't mean that those electrical patterns need to "look" anything like the images at all.

So for you to claim that no computer does this is false. That's precisely how all computers work. And there's no reason to think that a human brain doesn't work in a very similar fashion save for using analog methods instead of digital methods. That would be the only difference.

On a computer, not only is information stored but it can also be observed by transmitting it to a physical medium, like a monitor, speakers, etc. You failed to bring up that latter point which is why your explanation falls short of addressing my argument. To relate this back to the brain, I can agree that all of our experiences are stored in our memory. But how this information is translated into mental images is without any physical means and that's because the images are not objectively observable (unlike images from a digitial cameras) and our way of being aware of the mental imagery is through nonphysical means (using consciousness - w/out sensory organs which is again unlike images on digital cams).

So I still maintain that computers do not generate images like the mind does. Mental images, like hallucinations lack physical characteristics which is why they are not objectively and/or physically observable. There is no "purely physical" explanation to account for 'mental imagery'.

Leaving out key details of my point, like I explained earlier is one indication to me that you really have no case against my argument. And that's why I'll continue to use it on other sections of this thread and on other forums.

[benchwarmer]

You've failed to show how electrical activity gives rise to images when NO screen or other physical medium exist to actually view mental images. NO computer does this!

ALL computers do this!

DI is completely correct here.

Perhaps the difficulty is understanding what is happening when one 'views' something. For humans, this means that we sense the light reflected off of objects. We sense this light by having the light enter our eyes which then stimulates the retina causing electrical impulses. These electrical impulses are transported to our brain via the optic nerve. Part of our brain processes this signal as an 'image' that other parts of the brain perceive as the 'actual object' in front of us.

A mental image is simply converting stored information from one of the times we saw the object previously (our memories in our brain) into this same perceived 'image' in our head.

Exactly like a computer does. Computers use JPEG, WAV, MPEG, and various other formats for storing still pictures and videos. Those stored, physical representations are not the image themselves, they are data that is only useful to a process that understands how to decode them. Just like our brain. We actually had a discussion about this very topic a while back. Scientists were recreating images based purely on brain scans. i.e. the person thinks about an object and they were able to show an image on a screen that resembled the object being thought about. The image was not clear, but certainly roughly resembled the object being thought about. The limitation was not knowing the exact method our brain uses to store and encode images. Just like if I handed you a flash drive with a bunch of images using a proprietry encoding algorithm. It would just be 1s and 0s to anyone without the exact decoding algorithm.

Here's the latest from a google search:

https://www.engadget.com/2017/05/09/neu ... in-images/

[H.sapiens]

[Replying to post 10 by Divine Insight]
... and every time you haul that image out of storage to "remember" it, when you store it again it is slightly altered. After a few goes it may bear little actual resemblance to the original image. Such is the human brain.

[AgnosticBoy]

[quote="[url=http://debatingchristianity.com/forum/viewtopic.php?
DI is completely correct here.

Perhaps the difficulty is understanding what is happening when one 'views' something. For humans, this means that we sense the light reflected off of objects. We sense this light by having the light enter our eyes which then stimulates the retina causing electrical impulses. These electrical impulses are transported to our brain via the optic nerve. Part of our brain processes this signal as an 'image' that other parts of the brain perceive as the 'actual object' in front of us.

A mental image is simply converting stored information from one of the times we saw the object previously (our memories in our brain) into this same perceived 'image' in our head.

Exactly like a computer does. Computers use JPEG, WAV, MPEG, and various other formats for storing still pictures and videos. Those stored, physical representations are not the image themselves, they are data that is only useful to a process that understands how to decode them. Just like our brain. We actually had a discussion about this very topic a while back. Scientists were recreating images based purely on brain scans. i.e. the person thinks about an object and they were able to show an image on a screen that resembled the object being thought about. The image was not clear, but certainly roughly resembled the object being thought about. The limitation was not knowing the exact method our brain uses to store and encode images. Just like if I handed you a flash drive with a bunch of images using a proprietry encoding algorithm. It would just be 1s and 0s to anyone without the exact decoding algorithm.

Here's the latest from a google search:

https://www.engadget.com/2017/05/09/neu ... in-images/

DI is correct about how memory stores information. However, he did not address how the information can be viewed or perceived. The way that we perceive digital images and mental images are different. One is through physical means and the other lacks physical means. Secondly, mental images are not objectively observable while digital images are. This happens to be the strong point of my argument, and interestingly, it's the part that DI failed to address.

[Bust Nak]

I can observe the brain, but I can't observe mental images. This is a very clear/simple difference so there's something wrong with your logic.

I can observe the camera, but I can't observe digital images until it's printed out. No difference.

Again, clearly the two are not of the same nature but yet we experience both!

You say clearly but it's not clear at all.

That's why I consider them different types of experiences, one physical and the other non-physical.

The easy option is to consider them same type of experiences, both physical. As a continuation of our prior conversation, you are not gaining any more explanation power by introducing this concept of "non-physical" into the equation.

All I'm trying to get at is how can something non-physical (such as mental imagery - hallucinations) be explained in purely "physical" terms.

Loaded question cannot be answered. The premise that there is some non-physical thing waiting to be explained in purely "physical" terms is false. Instead we have something physical (such as mental imagery - hallucinations) to be explained in purely "physical" terms.

[Divine Insight]

Secondly, mental images are not objectively observable while digital images are. This happens to be the strong point of my argument, and interestingly, it's the part that DI failed to address.

You haven't shown that any such thing as "mental images" exist. So the claim that they are not objectively observable is meaningless.

I have addressed this precisely. Apparently you're just not understanding the points I'm making.

The brain can be running processes that produce the experience of having seen an imagine without any need to actually produce any images in the brain at all.

So your point isn't making any sense. You seem to think that there needs to be an actual picture in the brain that could be objectively seen. That's not the case at all.

So your entire model is simply wrong. What you think should be going on and what is actually going on are two entirely different things. No actual "images" need to exist in the brain. Yet you seem to be claiming that they need to objectively exist. They don't need to exist, so your entire approach is wrong.

[DrNoGods]

[Replying to post 14 by AgnosticBoy]

Secondly, mental images are not objectively observable while digital images are. This happens to be the strong point of my argument, and interestingly, it's the part that DI failed to address.

What exactly is your argument? I agree with everything DI said but don't see the connection between that, and your comment above about what he failed to address. A digital image produced on a computer screen or other device is not "directly observable" as far as its processing in the brain any more than a mental image. Both lead to a perception within the brain of an image, and this perception is created by the action of the neurons, memory elements, electrical signals, etc. within the brain.

In the case of the digital image you see it displayed on a screen, and the processing of that through the eyes, retina, optic nerve and visual cortex creates the perception of the image within the brain. In the case of a mental image, you "think" of it (eg. a pizza) and via the interactions of neurons, memory elements and electrical signals between them the perception of the pizza is created. There is no actual image of any sort in either case as far as what goes in within the brain. So I don't see what you are trying to argue.

Is your point that things like mental images, hallucinations, etc. are NOT created by the various brain components functioning normally, and instead are something supernatural or mysterious? If so, what is your counter argument as to how this is supposed to work. I see that you don't want to believe that mental images are simply the result of normal brain activity as DI has explained, but I don't see what your argument is against that, specifically. Is if that you just don't know the mechanisms involved and for that reason alone reject it?

[Divine Insight]

@AgnosticBoy

You seem to be thinking that there needs to be a screen inside the brain that produces an image that some little guy sitting on a chair in the brain can then look at this screen and see the image.

I doubt that there is a little man in the brain looking at images on a screen.

[AgnosticBoy]

I can observe the brain, but I can't observe mental images. This is a very clear/simple difference so there's something wrong with your logic.

I can observe the camera, but I can't observe digital images until it's printed out. No difference.

Nice try. You view the physical image through physical means. In other words, the image is transferred to some physical medium (a monitor, screen, or printed on paper) to be viewed and you're using your sensory organs to perceive it.

Compare this to a nonphysical/objectively unobservable mental image (like hallucinations) that is viewed via nonphysical means. In other words, unlike digital images, you are not viewing the mental image on a physical medium nor are you using sensory organs.

That's why I consider them different types of experiences, one physical and the other non-physical.

The easy option is to consider them same type of experiences, both physical. As a continuation of our prior conversation, you are not gaining any more explanation power by introducing this concept of "non-physical" into the equation.

Try first to describe or define what the phenomena involves before trying to explain it. It seems youi're doing it backwards by trying to fit the phenomena into your explanation.

Mental imagery is not objectively observable, it can only be experienced subjectively via introspection. Your explanation should incorporate all of this otherwise you're not really explaining the phenomena.

All I'm trying to get at is how can something non-physical (such as mental imagery - hallucinations) be explained in purely "physical" terms.

Loaded question cannot be answered. The premise that there is some non-physical thing waiting to be explained in purely "physical" terms is false. Instead we have something physical (such as mental imagery - hallucinations) to be explained in purely "physical" terms.

How are hallucinations physical when they don't occupy physical space? No materialist here has answered this question.