Mental imagery as non-physical perception pt. 2

[AgnosticBoy]

Critics of scientific realism ask how the inner perception of mental images actually occurs. This is sometimes called the "homunculus problem" (see also the mind's eye). The problem is similar to asking how the images you see on a computer screen exist in the memory of the computer. To scientific materialism, mental images and the perception of them must be brain-states. According to critics, scientific realists cannot explain where the images and their perceiver exist in the brain. To use the analogy of the computer screen, these critics argue that cognitive science and psychology have been unsuccessful in identifying either the component in the brain (i.e., "hardware") or the mental processes that store these images (i.e. "software").

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

I presented this argument a few months ago on this forum. I will play more of an information-seeking role here because I was left unsatisfied in the last thread. So again, I pose this challenge to materialists to use empirically-verifiable evidence to explain how or why mental images are physical when we DO NOT perceive them with our senses (hallucinations, dreams, etc).

Here's an easier way to put it:
1. Why aren't scientists able to observe our mental images (our hallucinations, dreams, etc) if they are physical?

2. Since perception involves our senses, then how am I able to perceive mental images without my senses?

I want scientifically verifiable peer-reviewed evidence-based answers to my questions. If you don't know, then just admit it. Don't simply tell me that scientists will figure it out - that's FAITH ... not scientific EVIDENCE.

[AgnosticBoy]

Just in case someone wants to cop-out and attempt to deny the existence of mental imagery:

Here's some science for using mental imagery...
Mental Simulation as Substitute for Experience by Dr. Heather Barry Kappes and Dr. Carey K. Morewedge (both writers hold a PhD in social psychology)

Abstract: In this integrative review, we examine four (non�exhaustive) cases in which mentally simulating an experience serves a different function, as a substitute for the corresponding experience. In each case, mentally simulating an experience evokes similar cognitive, physiological, and/or behavioral consequences as having the corresponding experience in reality.

Pg. 6
Mental practice is effective for both mental and physical tasks, but tasks for which cognitive activities are critical show greater mental practice effects than tasks merely requiring physical strength, endurance, and coordination.

Even though mental practice effectively improves performance, it is not a perfect substitute. Mental practice of a task alone is generally less effective than physical practice (Driskell et al., 1994). A combination of mental and physical practice, however, can be as or more effective in improving task performance than physical practice alone.

Pg. 7
Imaging sensory cues related to appetitive stimuli can evoke sensitization response similar to actual exposure to those sensory cues. If a person vividly imagines the smell of a food, for example, they exhibit increased salivation, a stronger desire to eat the food, and greater subsequent actual consumption of the food they, imagine smelling (Krishna, Morrin & Sayin, 2014).

The habituating and satiating effects of mental simulation are further evidence that mental simulation can act as a substitute for an experience (i.e., elicit the same responses as actual exposure to a stimulus).

[Divine Insight]

Here's an easier way to put it:
1. Why aren't scientists able to observe our mental images (our hallucinations, dreams, etc) if they are physical?

You should do a little research before making assumptions about what you think science doesn't know or can't do.

This is from 2009.

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This is from 2013

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This is from 2015

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This is from 2014

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This is now 2018, I'm sure they have made even more progress from what is shown in the videos above.

[AgnosticBoy]

[Replying to post 3 by Divine Insight]
Thanks for posting those videos. I've actually read some of the latest on these mind reading studies and if you understood how they were done then you'd see it is not about what I'm requesting. Let me elaborate on why.

First off, the researchers are not observing dreams and thoughts directly, but rather a computer "infers" from BRAIN ACTIVITY (cerebral blood flow to be exact which is not the mental images themselves) what the person is likely dreaming about. The second video you posted goes into some details on how the computer knows which brain activity corresponds to a certain image. Basically, the researchers do a brain scan while the subject is shown hundreds of images and the corresponding brain activity was recorded by a computer. So it has some mapped out information on which brain activity goes with a certain image. So when a new brain scan starts w/out showing images to the subject, the computer ties that current brain activity to all of the mapped out information (brain activity/image correlates) that it already has and infers an image from that.

To highlight some key points here..
- The scientists are not seeing actual mental images, but rather are seeing brain activity.
- The image that is produced is COMPUTER generated and it is inferred. If there was direct observation then you wouldn't need a computer to decode and infer an image. In relation to point 1, the inference is from brain activity which is not said to be the mental image itself.
- The scientists do not know nor are they claiming to know how brain activity leads to the perception of mental images.

So what we have here is a clever use of correlation at best and not causation! We also have indirect observation.

[benchwarmer]

[Replying to post 3 by Divine Insight]
Thanks for posting those videos. I've actually read some of the latest on these mind reading studies and if you understood how they were done then you'd see it is not about what I'm requesting. Let me elaborate on why.

First off, the researchers are not observing dreams and thoughts directly, but rather a computer "infers" from BRAIN ACTIVITY (cerebral blood flow to be exact which is not the mental images themselves) what the person is likely dreaming about. The second video you posted goes into some details on how the computer knows which brain activity corresponds to a certain image. Basically, the researchers do a brain scan while the subject is shown hundreds of images and the corresponding brain activity was recorded by a computer. So it has some mapped out information on which brain activity goes with a certain image. So when a new brain scan starts w/out showing images to the subject, the computer ties that current brain activity to all of the mapped out information (brain activity/image correlates) that it already has and infers an image from that.

To highlight some key points here..
- The scientists are not seeing actual mental images, but rather are seeing brain activity.

To be fair, when you dream you are not seeing actual images either. Are your eyes open when you see a mental image? No? Then you are simply recreating an image from stored data. Just like the computer is doing, albeit the computer does not have direct access to your neurons, it has to use data from detecting your access to neurons.

- The image that is produced is COMPUTER generated and it is inferred. If there was direct observation then you wouldn't need a computer to decode and infer an image. In relation to point 1, the inference is from brain activity which is not said to be the mental image itself.

Replace the word 'computer' with 'your brain' and you end up at the same thing. You are also inferring an image when your eyes are closed.

- The scientists do not know nor are they claiming to know how brain activity leads to the perception of mental images.

It's not all sorted out yet, but clearly they are starting to figure it out or they would not be able to do what they are doing with these experiments.

Even when you are seeing a 'live image' your brain is simply taking signal data from your optic nerves and generating a mental picture of what's actually there using your brain. When your eyes are closed, it likely uses the exact same mechanism except with stored data.

Since the computer does not have direct access to your brain matter, the best it can do is monitor activity. It's like trying to snoop what's showing on your computer monitor by putting a sensor around your video cable and trying to reproduce the image based on only the data available by signal detection.

So what we have here is a clever use of correlation at best and not causation! We also have indirect observation.

Technically, it's all indirect observation unless your eyes are open. Even then, one could argue it's indirect. Your eyes are detecting electromagnetic radiation, converting that to a signal on the optic nerve, then processing those signals in one part of your brain to feed information to other parts of your brain. Somewhere at the end of that signal chain 'you' perceive and image.

[DrNoGods]

[Replying to post 1 by AgnosticBoy]

1. Why aren't scientists able to observe our mental images (our hallucinations, dreams, etc) if they are physical?

Observe in what way? This sounds like you are suggesting that a physical 2D or 3D image in some construct is present in the brain (like DI's comment in the earlier thread that a little man is in your brain looking at a physical pattern that is the image). Why can't a mental image simply be a perception created by the brain as it organizes inputs from memory and neurons which act together (in a way we can't describe in detail yet) to create this perception? It happens every night in dreams as the brain fetches things from memory and creates the perception of full blown stories and sequences.

These can't be actual images created on a physical "screen" in the brain, so aren't physical in that sense. A memory isn't a physical thing either as far as the final perception in the brain, but results from the physical activity of neurons in a complex manner. The brain has the ability to assimilate the activity of its physical components to produce perception of mental images, and consciousness, but I don't see why you would think a mental image must be physical in terms of the image itself ... why can't it simply be a perception created by the brain as it assembles inputs from neuronal activity?

I want scientifically verifiable peer-reviewed evidence-based answers to my questions. If you don't know, then just admit it. Don't simply tell me that scientists will figure it out - that's FAITH ... not scientific EVIDENCE.

There are lots of papers published on this subject, and from a quick look at a few examples (links below), it appears that the research is still at the "we're trying to figure out the detailed mechanisms" stage. But all seem to point to mental images as simply perceptions created by the brain via neuronal activity, rather than any sort of physical "thing" in the brain that could be observed or measured in any way as a unit (ie. they are not physical as constructed units of some sort, but are created as a perception by the brain assembling input from its physical components).

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4595480/

http://journals.plos.org/plosone/articl ... ne.0142566

http://www.pnas.org/content/pnas/112/33/10089.full.pdf

http://ruccs.rutgers.edu/images/persona ... cs/ocm.pdf

http://www.cogsci.ucsd.edu/~coulson/203 ... c522983262

[Divine Insight]

To highlight some key points here..
- The scientists are not seeing actual mental images, but rather are seeing brain activity.

This isn't a "key point" at all. In fact, your entire view on this is utterly ridiculous.

In fact, benchwarmer already beat me to this.

Why are you expecting to see any actual "images" inside the brain?

What are you imagining? That the brain then has some hidden internal eyeballs that it uses to then 'look' at this image you expect to find inside the brain?

Your entire idea is totally ridiculous. There is no need for any actual image to be produced inside the brain. All that is required is to reform the brain activity that had occurred at the time you retina formed an image input that your brain had previously reacted to. In fact, you can form "images" in your mind of things you've never even seen before. Although, in truth you'll most likely be using patterns similar to those that had previously been produced when you had seen actual images.

The bottom line is that you are looking for something that doesn't even need to be there. No actual "images" need to exist inside the brain for a brain to create a thought patter that is equivalent to having seen an image.

So your supposed "Key Point" is utterly meaningless. You are demanding the existence of an actual visual image inside the brain that simply doesn't need to be there.

Having said this, I have read research that suggests that when we form images in our mind we "sometimes" (but not always) also cause activity to occur in the same places of the brain that are excited when the retina sends actual input from the outside world.

So there you have it. Even if you needed a "screen" upon which to display these images, the very same part of the brain that your retina activates could serve as that same screen. However, it appears from research that when we imagine seeing images in our mind we don't always activate those areas of the brain. So clearly that's not an actual requirement. But apparently some times that same area does become active in some cases.

So what you think is a "Key Point" is no point at all.

There is no need for an actual image to be produced within the brain. At least not in the same way that an image might be produced on a computer screen.

In fact, consider this:

Even computer programs that analyze images don't need to send the information to a visual screen before they can process it or analyze the data. So even a computer doesn't need to actually generate an image that we could "see" or recognize in order for the computer to be able to make sense of the data.

So there you have it. Even a computer doesn't need to "see" the image that it's processing in the same way that we would need to do with our eyeballs.

You seem to be thinking that a brain would actually need to be able to LOOK at an actual image in order to see it, but apparently that's not the case at all. The brain has no "internal eyeballs" with which to view images on a screen.

So you aren't even close to recognizing the actual situation. What you think should be important is not important at all. No actual "image" needs to exist inside a brain for a brain to "see" a mental image.

So you have it all wrong.

It's a good thing we don't need to depend on you to do this kind of research.

[AgnosticBoy]

To highlight some key points here..
- The scientists are not seeing actual mental images, but rather are seeing brain activity.

To be fair, when you dream you are not seeing actual images either. Are your eyes open when you see a mental image? No? Then you are simply recreating an image from stored data. Just like the computer is doing, albeit the computer does not have direct access to your neurons, it has to use data from detecting your access to neurons.

I agree that we don't "see" mental images, but there is still an experience (perception) of a mental image. I only use the word "seeing" for a lack of a better term. My main point however is that the scientists in these brain scan studies aren't observing the experiences directly.

- The image that is produced is COMPUTER generated and it is inferred. If there was direct observation then you wouldn't need a computer to decode and infer an image. In relation to point 1, the inference is from brain activity which is not said to be the mental image itself.

Replace the word 'computer' with 'your brain' and you end up at the same thing. You are also inferring an image when your eyes are closed.

We're talking about mental imagery here and not objects in the real world. I don't infer what my mental image is. I have a direct experience of it, and in fact, I can generate an image at will. The computer infers what my mental image would be (some studies report about a 60% success rate).

- The scientists do not know nor are they claiming to know how brain activity leads to the perception of mental images.

It's not all sorted out yet, but clearly they are starting to figure it out or they would not be able to do what they are doing with these experiments.

Good. I think that they'll figure it out but it just won't be entirely physical. Remember, all that they're relying on is correlation and indirect observation. My view is that we're dealing with emergent phenomena, so what starts out as physical doesn't need to stay physical across the board. At some level, a non-physical feature emerged from the brain.

So what we have here is a clever use of correlation at best and not causation! We also have indirect observation.

Technically, it's all indirect observation unless your eyes are open. Even then, one could argue it's indirect. Your eyes are detecting electromagnetic radiation, converting that to a signal on the optic nerve, then processing those signals in one part of your brain to feed information to other parts of your brain. Somewhere at the end of that signal chain 'you' perceive and image.

I already explained earlier how my perception of my mental imagery is not indirect. I KNOW (not guess) what my mental image is 100% of the time, especially when I'm in control of it. When I imagine a blue sky I'm actually DIRECTLY experiencing myself imagining a blue sky, whereas a computer is just surmising from correlated brain activity. These computers are getting it right only 60% of the time, at best, and in all honesty, a lot of the pictures are blurry.

[AgnosticBoy]

1. Why aren't scientists able to observe our mental images (our hallucinations, dreams, etc) if they are physical?

Observe in what way? This sounds like you are suggesting that a physical 2D or 3D image in some construct is present in the brain (like DI's comment in the earlier thread that a little man is in your brain looking at a physical pattern that is the image).

I'm not limiting scientists to finding an actual image. You can label the experience whatever you'd like just as long as you don't deny that it involves a visual-like experience, like seeing faces, colors, shapes, etc. I'm simply questioning why they can not observe what I'm experiencing if mental imagery is physical.

Your question really strengthens my point. You don't even know what physical form this experience has but yet you assume it's "physical".

Why can't a mental image simply be a perception created by the brain as it organizes inputs from memory and neurons which act together (in a way we can't describe in detail yet) to create this perception? It happens every night in dreams as the brain fetches things from memory and creates the perception of full blown stories and sequences.

The problem is that the perception is occurring without the senses. So it would fall into the same homunculus problem unless you have some other empirically verifiable explanation that shows how or why we're perceiving and where is this perception taking place.

My view is that the phenomena is just as non-physical as hallucinations are. Consciousness itself is a non-physical faculty that is able to "see" or scan the mind. It doesn't have to obtain information the same way our senses does which is why I use words like scan although even that may be too simplistic.

These can't be actual images created on a physical "screen" in the brain, so aren't physical in that sense. A memory isn't a physical thing either as far as the final perception in the brain, but results from the physical activity of neurons in a complex manner. The brain has the ability to assimilate the activity of its physical components to produce perception of mental images, and consciousness, but I don't see why you would think a mental image must be physical in terms of the image itself ... why can't it simply be a perception created by the brain as it assembles inputs from neuronal activity?

I already explained through a series of questions why there are some problems with your view of perception.

Again, this should be easy for scientists since it's all physical. What I'm asking shouldn't even require a complete understanding of consciousness. I'm simply asking why aren't scientists able to directly observe what we're experiencing if our mental experience is all physical?

From what I gather so far, you do not have a scientific verifiable explanation to support your position.

[AgnosticBoy]

To highlight some key points here..
- The scientists are not seeing actual mental images, but rather are seeing brain activity.

This isn't a "key point" at all. In fact, your entire view on this is utterly ridiculous.

In fact, benchwarmer already beat me to this.

Why are you expecting to see any actual "images" inside the brain?

You seem to be shifting your position a bit. You posted a study that presumes that we experience image-like in our minds (which is the whole point of your posted study being about seeing our thoughts and using computer to show the images we're thinking), but now you're against it once I exposed a problem with your conclusion.

What are you imagining? That the brain then has some hidden internal eyeballs that it uses to then 'look' at this image you expect to find inside the brain?

I make no claims on how we perceive mental images other than the fact that we don't use our senses. We are perceiving (experiencing) something. This is the materialists time to offer some sensible scientifically verifiable answers.

If mental images are physical, as you claim, then I want to know why scientists can not directly observe them?

Your entire idea is totally ridiculous. There is no need for any actual image to be produced inside the brain. All that is required is to reform the brain activity that had occurred at the time you retina formed an image input that your brain had previously reacted to. In fact, you can form "images" in your mind of things you've never even seen before. Although, in truth you'll most likely be using patterns similar to those that had previously been produced when you had seen actual images.

There is something that is very much like an image but I don't claim that it's in the brain. It's no where just like a hallucination but the experience still exist, which is why I bring up non-physical experience.

The bottom line is that you are looking for something that doesn't even need to be there. No actual "images" need to exist inside the brain for a brain to create a thought patter that is equivalent to having seen an image.

Okay, so if it's physical, where does it exist if not in the brain? Why can't scientists perceive it?

Having said this, I have read research that suggests that when we form images in our mind we "sometimes" (but not always) also cause activity to occur in the same places of the brain that are excited when the retina sends actual input from the outside world.

So there you have it. Even if you needed a "screen" upon which to display these images, the very same part of the brain that your retina activates could serve as that same screen. However, it appears from research that when we imagine seeing images in our mind we don't always activate those areas of the brain. So clearly that's not an actual requirement. But apparently some times that same area does become active in some cases.

This supports the view that there is something image-like going on when it comes to mental imagery. But of course it's missing some factors if you wanted to claim that it serves as a screen to display images. You'd have to explain light, perceiver, etc.

In fact, consider this:

Even computer programs that analyze images don't need to send the information to a visual screen before they can process it or analyze the data. So even a computer doesn't need to actually generate an image that we could "see" or recognize in order for the computer to be able to make sense of the data.

So there you have it. Even a computer doesn't need to "see" the image that it's processing in the same way that we would need to do with our eyeballs.

You seem to be thinking that a brain would actually need to be able to LOOK at an actual image in order to see it, but apparently that's not the case at all. The brain has no "internal eyeballs" with which to view images on a screen.

The information for an image can exist without a screen, but it is not in image form that can be experienced or visualized until it reaches a screen, where it can display color, motion, etc. I don't have any knowledge of the form of my memories until I'm somehow able to change them to an image-like experiential form.

People should also factor in that there are limitations to computer/brain analogy, as well. We can also build and modify computers to work however we need them to but that will not always translate to the brain. Just because I can transfer my computer files to another computer, doesn't mean I can transfer memories to another brain.