Myth of evolution and new drug discovery

[itinerant1]

Sure - would be happy to do this. Needs a new thread. Do you want to start?

Alec
evolutionpages.com/Schoenborn_critique.htm

Soon. I’ll let you know when. I have too many things going during the next few days to start now.

 

[itinerant1]

A thought on speciation:

Some folks on CAF have difficulty with the idea of macro-evolution, specifically speciation. Rather than present clear examples of macro-evolution, I thought the life stages of species in the order Lepidoptera present transitional phenomena more amazing in many ways than speciation.

The process of holometabolous metamorphosis is absolutely incredible. Inside the chrysalis the caterpillar’s body is totally liquefied by digestive fluids. In this enzymatic soup a new body is restructured using specialized formative cells. A process called histogenesis takes place, in which undifferentiated cells are used to build different body tissues.

When metamorphosis is complete, an individual with a very different body structure emerges and flies away. Now that is miraculous!

Speciation seems like small potatoes compared to this biological feat.

 

[Techno2000]

A thought on speciation:

Some folks on CAF have difficulty with the idea of macro-evolution, specifically speciation. Rather than present clear examples of macro-evolution, I thought the life stages of species in the order Lepidoptera present transitional phenomena more amazing in many ways than speciation.

The process of holometabolous metamorphosis is absolutely incredible. Inside the chrysalis the caterpillar’s body is totally liquefied by digestive fluids. In this enzymatic soup a new body is restructured using specialized formative cells. A process called histogenesis takes place, in which undifferentiated cells are used to build different body tissues.

When metamorphosis is complete, an individual with a very different body structure emerges and flies away. Now that is miraculous!

Speciation seems like small potatoes compared to this biological feat.

So has evolution stopped for the Butterfly or will it eventually evolve into something else ?

 

[itinerant1]

So has evolution stopped for the Butterfly or will it eventually evolve into something else ?

No reason to think it won’t continue to evolve.

 

[Techno2000]

No reason to think it won’t continue to evolve.

How about the reason that it is perfect like God made it to be ?

 

[itinerant1]

How about the reason that it is perfect like God made it to be ?

Well, I suppose it got to be the way it is by evolving and adapting to the environment. When the environment changes, those variations most fit to survive will do so, and evolution rolls on. Of course, most species tend to go extinct. That would be about 90-99% of God’s perfect species. The very thing that allows them to survive contributes to their demise, i.e. over specialization, for instance. Koalas will be in a pickle if Eucalyptus dies out.

 

[123rock]

I’m afraid I don’t see at all where TS is in over his head - in fact, I’d say yours are the arguments that are embarrassed. As far as I can see you are relying on the necessary/sufficient distinction, and having to do so increasingly urgently as more and more evidence emerges that every human cognitive aspect has a neural correlate, and moreover that cognitive aspects depend on the functioning of the specific neural subsystem. It is even the case that individual neurons can be shown to fire if and only if the subject is presented with a specific concept such as the picture of or the written name of an individual - see for example Quiroga et al, Invariant visual representation by single neurons in the human brain, *Nature *435, 1102 - 1107 (2005)

Given these findings, it is clear that the material brain is *necessary *for all that we ascribe to mind. So now, the question becomes “is it sufficient?”, and here the burden of evidence falls on you. We have increasingly more precise correlation between brain states and mind states, and we know that brain states are real phenomena of matter-energy, so the default explanation is that mental states and brain states are different aspects of the same phenomenon. We should of course, revise that conclusion if we find a compelling reason to suppose that the material brain is insufficient to cause the phenomena we ascribe to mind, but I have seen so far no compelling evidence that there is such evidence or reason. Of course, I have come late into the thread, so I hope you’ll be kind enough to repeat it or link to it if I’ve missed it.

This doesn’t mean anything. By your theory, if this proves there is no “thinker behind the thought” then a telephone receiver proves there is no person behind the phone. The brain may be the way to physically communicate spirituality, but does not mean it is all there is which makes thought.

 

[itinerant1]

This doesn’t mean anything. By your theory, if this proves there is no “thinker behind the thought” then a telephone receiver proves there is no person behind the phone. The brain may be the way to physically communicate spirituality, but does not mean it is all there is which makes thought.

The logically unwarranted leap in the position is his following statement:
“so the default explanation is that mental states and brain states are different aspects of the same phenomenon.”

This is actually no explanation at all, merely an unproven assumption made at the outset, and it remains unproven by subsequent data. I would go further and state that all of the ongoing good quality brain research tends to disprove the above stated assumption.

 

[itinerant1]

Addendum:

An example of poor quality research and interpretation is found in the text hecd2 quoted from Nature:

“It is even the case that individual neurons can be shown to fire if and only if the subject is presented with a specific concept such as the picture of or the written name of an individual - see for example Quiroga et al, Invariant visual representation by single neurons in the human brain,”

Notice what is being talked about are visual activities involving a “picture” and a “written name”. These are referred to as a “specific concept”. Cognitive research doesn’t get much sloppier and confused than that. (Well, actually it does.) There is no distinction made between sense perception and intellectual conception. Perception is treated as conception in the quote. So, the quote amounts to nothing more than junk science.

 

[itinerant1]

Addendum:

An example of poor quality research and interpretation is found in the text hecd2 quoted from Nature:

“It is even the case that individual neurons can be shown to fire if and only if the subject is presented with a specific concept such as the picture of or the written name of an individual - see for example Quiroga et al, Invariant visual representation by single neurons in the human brain,”

Notice what is being talked about are visual activities involving a “picture” and a “written name”. These are referred to as a “specific concept”. Cognitive research doesn’t get much sloppier and confused than that. (Well, actually it does.) There is no distinction made between sense perception and intellectual conception. Perception is treated as conception in the quote. So, the quote amounts to nothing more than junk science.

Correction: I said hecd2 quoted from Nature. I checked the original post and I see that he is just referring to Nature. My critique still applies to the words I quoted from his post.

 

[123rock]

You’re right. The assumption that mental states, such as a person’s ideas and desires are an aspect of the same source responsible for brain states such as sleep and so on is the major assumption. Clearly a person without a brain doesn’t have ideas, but neither can a phone without a speaker have any sound. Does that mean that when you call someone and get no reception you don’t actually exist just because the other person’s phone doesn’t work! Of course not, and in the same way just because your brain may not be able to allow you to communicate ideas you would normally be able to, does not mean it is only your brain as a natural collection of neurons that is responsible for them.

 

[itinerant1]

You’re right. The assumption that mental states, such as a person’s ideas and desires are an aspect of the same source responsible for brain states such as sleep and so on is the major assumption. Clearly a person without a brain doesn’t have ideas, but neither can a phone without a speaker have any sound. Does that mean that when you call someone and get no reception you don’t actually exist just because the other person’s phone doesn’t work! Of course not, and in the same way just because your brain may not be able to allow you to communicate ideas you would normally be able to, does not mean it is only your brain as a natural collection of neurons that is responsible for them.

I suppose we can illustrate the mind-body issues, at least in a limited way, using analogies with technology. How about this one: the metaphysical materialist can see when the light is switched on, but he refuses to believe anyone is ever home.

Actually, I can recall an illustration I read one time. It involves a conscious subject who has his brain exposed during a brain study. The scientist monitors areas of the brain pertinent to the activities the subject will be engaging in. The scientist has a secretary at his side who writes down the scientist’s observations as he communicates them to her.

Now, the subject proceeds to verbally describe whatever he sees as his eyes look about the room. The subject has his own secretary who writes down everything the subject communicates.

Afterward, if you compare what the two secretaries each wrote down, there is absolutely no similarity in what they recorded. Those who identify mind as strictly brain activity are unable to account the differences in what the secretaries recorded.

 

[Touchstone]

Addendum:

An example of poor quality research and interpretation is found in the text hecd2 quoted from Nature:

“It is even the case that individual neurons can be shown to fire if and only if the subject is presented with a specific concept such as the picture of or the written name of an individual - see for example Quiroga et al, Invariant visual representation by single neurons in the human brain,”

Notice what is being talked about are visual activities involving a “picture” and a “written name”. These are referred to as a “specific concept”. Cognitive research doesn’t get much sloppier and confused than that. (Well, actually it does.) There is no distinction made between sense perception and intellectual conception. Perception is treated as conception in the quote. So, the quote amounts to nothing more than junk science.

The Quiroga experiment from 2005 is all about abstraction of discrete percepts, encoding them in specific neurons in the medial medial temporal lobe. The whole point of the study to was isolate neurons that were invariant across **multiple different images of the same person. **And it goes beyond facial recognition, as some of the images were text – “Halle Berry”, as opposed to a picture of her, for one of the test images, for example.

That’s important because activity of these neurons fire as a matter of abstraction – the different images and words are coalesced into a representation that reacts to, say, Halle Berry, where “Halle Berry” is NOT a particular image, or a particular word, but an abstraction of Halle Berry – the same neuron activity lights up from a conventional picture of her face, a picture of her as Cat Woman, and a textual representation of her name.

From the June 2005 Nature piece:

How neurons encode different percepts is one of the most intri- guing questions in neuroscience. Two extreme hypotheses are schemes based on the explicit representations by highly selective (cardinal, gnostic or grandmother) neurons and schemes that rely on an implicit representation over a very broad and distributed popu- lation of neurons1–4,6. In the latter case, recognition would require the simultaneous activation of a large number of cells and therefore we would expect each cell to respond to many pictures with similar basic features. This is in contrast to the sparse firing we observe, because most MTL cells do not respond to the great majority of images seen by the patient. Furthermore, cells signal a particular individual or object in an explicit manner27, in the sense that the presence of the individual can, in principle, be reliably decoded from a very small number of neurons. We do not mean to imply the existence of single neurons coding uniquely for discrete percepts for several reasons: first, some of these units responded to pictures of more than one individual or object; second, given the limited duration of our recording sessions, we can only explore a tiny portion of stimulus space; and third, the fact that we can discover in this short time some images —such as photographs of Jennifer Aniston —that drive the cells suggests that each cell might represent more than one class of images. Yet, this subset of MTL cells is selectively activated by different views of individuals, landmarks, animals or objects. This is quite distinct from a completely distributed population code and suggests a sparse, explicit and invariant encoding of visual percepts in MTL. Such an abstract representation, in contrast to the metric representation in the early stages of the visual pathway, might be important in the storage of long-term memories.

(my emphasis)

This is not simple percept isomorphism, one to one mappings between a particular visual stimulus and a particular neuron; neurons here are observed to encode abstractions.

-TS

 

[Touchstone]

Correction: I said hecd2 quoted from Nature. I checked the original post and I see that he is just referring to Nature. My critique still applies to the words I quoted from his post.

Quiroga’s more recent follow up [1] to the 2005 study adds spoken words and names to the modes, and finds that, for example, a neuron located in the left anterior hippocampus reacts selectively for “Oprah Winfrey”, where “Oprah Winfrey” is represented to the test subject by various pictures of her, a textual representation of her name (“Oprah Winfrey”), as well as spoken audio (a recording of someone saying “Oprah Winfrey” is played for the subject).

From the summary:

By using presentations of pictures and of spoken and written names, we show that (1) single neurons in the human medial temporal lobe (MTL) respond selectively to representations of the same individual across different sensory modalities; (2) the degree of multimodal invariance increases along the hierarchical structure within the MTL; and (3) such neuronal representations can be generated within less than a day or two. These results demonstrate that single neurons can encode percepts in an explicit, selec- tive, and invariant manner, even if evoked by different sensory modalities.

and later:

Given the previous finding that human MTL neurons can be activated by visual imagery [29], it might be in principle possible that the text and sound activations reported here are just responses to visual imagery. However, this possibility is unlikely for two reasons. (1) It seems more difficult to elicit spontaneous imagery responses with eyes open, as in our experiments, than when subjects are specifically asked to imagine a picture with eyes closed, as in [29]. (2) The responses to the text and sound stimuli were as strong as the ones to the pictures and there was a relatively small delay of less than 100 ms between the responses to the picture and text presentations, likely resulting from the different times required to understand a text and recognize a face. The responses to sound stimuli were much later because in this case the presentation onset is not as clearly defined as with pictures. In contrast to these findings, imagery responses have been reported to be weaker than those to picture presen- tations and with a more variable and larger delay (the latency of imagery responses was more than 200 ms longer than the one to the picture responses) [29, 30].

Just in case you or anyone else should suppose this is just “visual stacking”.

-TS

[1] Quian Quiroga R, Kraskov A, Koch C, Fried I., ** Explicit Encoding of Multimodal Percepts by Single Neurons in the Human Brain**,* Current Biology*, Volume 19, Issue 15, 1308-1313, 23 July 2009 (doi:10.1016/j.cub.2009.06.060)

 

[itinerant1]

Quiroga’s more recent follow up [1] to the 2005 study adds spoken words and names to the modes, and finds that, for example, a neuron located in the left anterior hippocampus reacts selectively for “Oprah Winfrey”, where “Oprah Winfrey” is represented to the test subject by various pictures of her, a textual representation of her name (“Oprah Winfrey”), as well as spoken audio (a recording of someone saying “Oprah Winfrey” is played for the subject).

From the summary:

and later:

Just in case you or anyone else should suppose this is just “visual stacking”.

-TS

[1] Quian Quiroga R, Kraskov A, Koch C, Fried I., Explicit Encoding of Multimodal Percepts by Single Neurons in the Human Brain,* Current Biology*, Volume 19, Issue 15, 1308-1313, 23 July 2009 (doi:10.1016/j.cub.2009.06.060)

It’s good to resort to the original text of a study rather than a secondary account.

However, this still does not deal with the fundamental issue of the distinction between percepts and concepts and the relation that obtains in human cognition. This is critical for understanding the mind-brain relationship.

Agnosia presents instances of blind percepts. The implications of that pathology represent further evidence against the mind-brain identity hypothesis. There is nothing in the multi-modal percepts study that remotely suggests that consciousness and conceptual thinking is sufficiently accounted for by brain states. The studies are nonetheless immensely interesting and worthwhile.

 

[grannymh]

Quiroga’s more recent follow up [1] to the 2005 study adds spoken words and names to the modes, and finds that, for example, a neuron located in the left anterior hippocampus reacts selectively for “Oprah Winfrey”, where “Oprah Winfrey” is represented to the test subject by various pictures of her, a textual representation of her name (“Oprah Winfrey”), as well as spoken audio (a recording of someone saying “Oprah Winfrey” is played for the subject).

From the summary:

and later:

Just in case you or anyone else should suppose this is just “visual stacking”.

-TS

[1] Quian Quiroga R, Kraskov A, Koch C, Fried I., Explicit Encoding of Multimodal Percepts by Single Neurons in the Human Brain,* Current Biology*, Volume 19, Issue 15, 1308-1313, 23 July 2009 (doi:10.1016/j.cub.2009.06.060)

Thanks for this citation. I will try to access it. Also, I am interested in the citation for the previous 2005 research.

 

[Fran65]

There is nothing in the multi-modal percepts study that remotely suggests that consciousness and conceptual thinking is sufficiently accounted for by brain states.

The use of blindsight against the mind-brain identity argument is problematic however, as it is entirely possible that due to brain injury all that is missing is the conscious knowledge or the ability to articulate what has been presented visually. This may also be mediated neurologically. I hope that I have understood your point correctly.

 

[Touchstone]

Thanks for this citation. I will try to access it. Also, I am interested in the citation for the previous 2005 research.

Here’s the cite for the 2005 article, (it’s actual in the “letters” section, which is a little different):
R. Quian Quiroga, L. Reddy, G. Kreiman, C. Koch and I. Fried. Invariant visual representation by single-neurons in the human brain.**** Nature, 435: 1102-1107; 2005.

That links directly to the PDF of the full article, which is free to download. Read and enjoy, it’s a really accessible, interesting piece.

The recent article I cited above (Quiroga, et al, [2009]) can also be downloaded for free from here:

vis.caltech.edu/~rodri/papers/Curr_Bio_09.pdf

If you read one, you should read the other.

-TS

 

[itinerant1]

The use of blindsight against the mind-brain identity argument is problematic however, as it is entirely possible that due to brain injury all that is missing is the conscious knowledge or the ability to articulate what has been presented visually. This may also be mediated neurologically. I hope that I have understood your point correctly.

You raise an interesting possibility. My point was actually scattered over multiple posts, and has to do with the mistaken tendency to conflate percepts and concepts. To use a Kantian expression without endorsing his epistemology, percepts without concepts are blind, and concepts without percepts empty.

The case of the man who mistook his wife for his hat is interesting. Also, when the subject does not perceive a rose through two sense modalities, sight and touch, but recognizes it upon smelling the rose has suggested in fact the absence of conscious knowledge, which is why there is nothing to articulate.

Related neurological activity should be present in the “blindsight” seeing and touching but not the corresponding conceptualization needed to “recognize” this object as a rose. In humans, sense perception is almost always accompanied by intellectual conception.

This is the fundamental difference between human and animal sense perception.

The detection of corresponding neural activity in the brain consequent to sense perception is apparently a detection of physiological conditions sufficient to account for sensory activity in sub-human animals, but not so in humans. My point is that in humans, neuro-physiological activity is only necessary but not a sufficient condition for conceptual activity.

There is a difference when an animal perceives a rose and when a human perceives a rose. The animal has no accompanying abstract conceptualization that understands this flower as being of a certain “kind”.

Conceptualization allows me to rise above the immediate environment perceived with the senses and know things that are not part of the environment, and even know things that cannot be instantiated physically.

 

[Fran65]

I see what you mean. So you are arguing that the neurological correlates are sufficient for sense perception in animals but this is not the case with intellectual conception in humans. In which case blindsight subjects have sense perception (hence their performance on forced choice responses), but have lost their ability to link these perceptions with intellectual conception - hence their inability to articulate and to be aware of what they have perceived. You are arguing that Quiroga et al’s 2005 study has demonstrated the link with sense perception, but not the link with intellectual conception. What would be needed is a similar methodology but with subjects who are engaged in abstract thought - following an instruction such as “think about justice”. These could be criticised as being insufficiently controlled however.