Genes and brain structure

[jake williams]

I totally don't understand how this works at all. How the hell do genes have enough information to determine specific neurological structures, say the language system? My knowledge of biology is pretty weak, but I certainly have some understanding of the basic concept of how genes create proteins and the proteins create cells. I can even sort of understand how certain patterns of cell growth would create your muscle tissue and your bone tissue and so on. But I really have no idea at all how DNA accomplishes the horrifically complex task of orienting neurons and leading to certain... synaptic patterns? or whatever it would take to make anything like an infant's brain.

Any insight? Like sort of some dumbed down insight?

[Rosa Lichtenstein]

I can upload a paper that attacks the idea that the 'mind'/language is genetically determined, if you are interested?

[Rosa Lichtenstein]

In fact, here it is:

http://rapidshare.com/files/164017154/langgene.pdf.html

[DesertShark]

Yay! I love this stuff! :lol:

I can break down any and all of the following for you:
-what parts of the brain do what and how some of those interact
-how the nervous system develops (starting from DNA and going up to the full nervous system a normal person is born with) *this might be the one you want
-how neurons talk to each other
-how a neuron talks to a muscle or anything else in the body
-how somatic sensory systems work
-how motor systems work
-how some diseases that effect the previous two work
-and how we know all these things (ie who did what experiments and when, what experiments are done now that you could do to see these results, and some current papers on new findings)

Just let me know!

-DS

[benhur]

DS,

Can you explain more about how neurons talk to each other? Also, how genes are responsible for creating sentience/consciousness? If they're not, what's it that makes animals/humans conscious, and not stones and the rest?

[jake williams]

-how the nervous system develops (starting from DNA and going up to the full nervous system a normal person is born with) *this might be the one you want
-and how we know all these things (ie who did what experiments and when, what experiments are done now that you could do to see these results, and some current papers on new findings)

These two.

[DesertShark]

How Neurons "Talk" to Each Other

I think that pictures make understanding this stuff a lot easier so the links are to images that are pretty standard in biology and neurobiology text books (just did an image search of neurons and picked ones I'd seen a million times, they're all pretty much the same).
First, a super simple cartoon image of a neuron and it's basic parts: http://www.daviddarling.info/images/neuron_labeled_diagram.jpg
Simple cartoon image of two neurons communicating (a very basic setup): http://kvhs.nbed.nb.ca/gallant/biology/neuron_structure.jpg
And a simple cartoon of a neuron synapse (where the neurons are actually interacting): http://anthropologynet.files.wordpress.com/2008/01/neuron-synapse.png

There are a variety of neuron types (http://www.lpmpjogja.diknas.go.id/kc/b/brain/brain-neuron-types.gif) (over 50 have been distinguished), so the images above very simplified but the following concepts are the same throughout neuron communication.

You have the presynaptic neuron (the one sending the signal) and a postsynaptic neuron (the one receiving the signal). The presynaptic neuron will have its synpatic terminals (or terminal boutons) on the the postsynaptic neuron in any of the following places: the dendrites (on dendritic spines is where we find most synapses), the cell body, the axon, and even just before the terminal bouton. This location (the location of the synapse) determines the speed to which the postsynaptic neuron will fire in response. Speed of firing is also dependent on the neurons conductance. Conductance is how much ion is moving across membrane, its inversely related to resistance. The bigger gives less resistance, mylenation increases resistance of ions leaving and increases conductance speed. Current travels down the path of least resistance. Conductance is similar to permeability.

For a neuron to send a signal the membrane potential (which can be measured by a volt meter, is the voltage difference between the inside and outside of the cell) has to break threshold, which differs depending on the type of neuron and what it is doing. The 'normal' (average/most common) resting membrane potential is -65mV (due to permeability of membrane to K+, more abundant K+ leak channels than any other). This ('breaking threshold') iniates an action potential (http://www.gregalo.com/action_potential.jpg). An action potential is a transient inward current then a gradual outward current; it is an all or nothing response meaning that once you break threshold, there's no going back.

The cell membrane of the neuron is littered with sodium (Na+) channels, potassium (K+) channels, sodium/potassium ATP pumps (Na+/K+ pumps), other voltage-gated channels, ligand-gated channels, and ion transporters.
-Ion transporters move ions against concentration gradients to maintain unequal gradients, produce potential energy gradients that can be utilized for communication.
-Ion channels (Na+ channels, K+ channels, Ca2+ channels, etc) once open allow ions to diffuse passively down concentration gradients, selectively permeable, allow for harnessing of stored potential energy, used to transmit information
-ATP pumps keep concentration gradient, maintains osmolarity, and restores resting membrane potential; it needs ATP (energy) and ion gradient to work (these pumps make up 20-40% of ATP usage in body).
-Votage gated channels open when the membrane potential reaches or passes a specific voltage. They influence action potentials. The voltage sensor of the channel is a string of basic amino acids (positively charged).
-Ligand gated channels open when a specific ligand binds to the channel. They influence localized graded/receptor potentials.
-Membrane potential (Vm) can override concentration gradient. Manipulating Vm can manipulate ion movement.
-With the concentration gradient, Na+ 'wants' to move into the cell and K+ 'wants' to move out.

Ok so what happens during an action potential? Both Na+ and K+ voltage channels (they open at the same voltage reading, but K+ has slower kinetices and doesn't inactivate) open flooding the cell with positive ions (Na+) causing an increase in membrane potential. The peak of the action potential is Na+ membrane potential, no more Na+ can flow in because the gradient that drove the influx is now gone. The downward slope is K+ leaving the cell, which brings the membrane potential back toward resting. It overshoots and Na+/K+ pumps bring it up to resting. The refractory period is the time in the falling phase (downward slope) of the action potential when no additional stimulus will initiate additional action potential (absolute). This is due to Na+ channel inactivation and a slow decrease conductance of K+; Na+ channel has a 'ball & chain' inactivation loop. During the relative refractory period (the overshoot part) it takes a supra-threshold stimuli to fire an action potential.

The action potential occurs all the way down the neuron until it reaches the terminal bouton at the synapse. When the action potential travels down the axon (which is normally mylenated) it moves by saltatory conductance at the Nodes of Ranvier. Saltatory conductance increases velocity of signal down axon. Once the signal reaches the terminal bouton, it causes an influx of calcium (Ca2+) into the cell.

Ca2+ in the terminal bouton does a lot of things. I won't go into detail unless someone wants me to. The basic thing that happens is: the Ca2+ causes the release of neurotransmitters into the synapse. The neurotransmitters cross the synapstic cleft and bind to it's specific receptors on the postsynaptic neuron (the link to the picture of the synapse I gave earlier, linked here (http://anthropologynet.files.wordpress.com/2008/01/neuron-synapse.png), gives a basic view of this process). There are many neurotransmitters and each does different things to different cells. They can be inhibitory which makes the postsynaptic cell unable to fire or they can be excitory which makes the postsynaptic fire (the whole action potential thing happens again). Neurons are connected to many many many other neurons at the same time and their firing or not depends on the amount of excitatory and inhibitory signals they get.

Some of the 'how we know' for this stuff:
-Golgi came up with the Golgi stain which only stains neurons (and only about 10%) but you can see the whole neuron.
-Cajal (late 1800s/early 1900s) came up with the neuron doctrine using the Golgi stain, he's the "father" of neuroanatomny. Neuron doctrine: "neurons are distinct cells that communicate via synapses, not continuity". Won Nobel prize for this (shared with Golgi) in 1906. The neuron doctrine was confirmed by the electron microscrope, invented in 1950s.
-Cole created the voltage clamp (http://www.ebme.co.uk/arts/aps/pic1a.gif) which allows you to the voltage at whatever you want (command voltage) and a current gets injected to make that happen (battery). Its used to characterize membrane permeability changes due to Vm and time.
-A giant squid axon was used in the early experiments on neurons because they're so much bigger then our neurons. Keynes showed the Na+/K+ pumps. Hodgkin and Katz showed the resting membrane potential was caused by K+ (they kept increasing the outside K+ concentration). Hodgkin and Huxley found Na+ and K+ permeability changes cause action potential, they also found the threshold; used TTX which blocks Na+ channels and TEA which blocks K+ channels (TTX is a neurotoxin found in fish called Tetraodontiformes (http://en.wikipedia.org/wiki/Tetraodontiformes), TEA is also a neurotoxin called tetraethylammonium).
-Patch clamp technique is used to measure one or two channels (if you want me to explain it I can).

-DS

PS- I'll get to any questions and the nervous system development stuff when I get back on sunday or monday.

[Rosa Lichtenstein]

How does any of this show they talk to one another? Are they human beings?

[jake williams]

Are they human beings?
Yes.

[Rosa Lichtenstein]

So, neurons are little human beings, are they?

If so, do they have their own neurons?

If "yes", how do they 'talk' to one another? [And so on, forever...]

If "no", how can they be human beings?

[benhur]

How does any of this show they talk to one another? Are they human beings?

It's just a poetic way of saying they're sentient, that's all.

[Rosa Lichtenstein]

BenHur:


It's just a poetic way of saying they're sentient, that's all.

But, neurons aren't sentient. Human beings are.

[DesertShark]

How does any of this show they talk to one another? Are they human beings?
That happens a lot in science where human characteristics are used to describe how things work (a positive ion is "attracted" to a negative ion), I didn't realize it would be a big deal on here (but I will check my language from now on). That was part of the reason "talk" was in the quotations in the title, I didn't mean literally.

So neurons don't "talk" in the sense that they vocalize words or sounds. They "talk" in the sense that they communicate information with one another and across the peripheral and central nervous systems.

For example, you touch something hot. A "message" (electrical signal sent by nerves and neurons - in this case a sensory input indicating temperature change on a specific portion of your body) is sent from the skin through your body by nerves to your spinal cord and up to your brain (also by nerves, which are only found in the peripheral nervous system). Two things happen there, neurons involved in motor response are alerted (stimulated and/or inhibited) and respond (cause other neurons and eventually nerves to be stimulated and/or inhibited) and the "message" is analyzed/interrupted/conceptualized (you put a label on and words to what's happening). If you want to move your hand away so you don't burn your skin, the input from the skin has to be received and properly responded to by the motor areas of the brain and the muscles in the body. Or you can override it keep your skin there longer. If you want to vocalize what just happened ("hey that's hot"), neurons in the speech/language and motor portions of your brain have to be alerted and respond properly.

[Rosa Lichtenstein]

DS:


They "talk" in the sense that they communicate information with one another and across the peripheral and central nervous systems.

Thanks for the clarification, but I am afraid that "communicate" and "information" are not much better, since these words are metaphorical too!

[DesertShark]

DS:
Thanks for the clarification, but I am afraid that "communicate" and "information" are not much better, since these words are metaphorical too!

I think communicate and information both work and are not metaphorical. If you look at the following definitions of the words.

Definition of communication from http://wordnet.princeton.edu/perl/webwn?s=communicate:
"(v) communicate, pass on (http://wordnet.princeton.edu/perl/webwn?o2=&o0=1&o7=&o5=&o1=1&o6=&o4=&o3=&s=pass+on), pass (http://wordnet.princeton.edu/perl/webwn?o2=&o0=1&o7=&o5=&o1=1&o6=&o4=&o3=&s=pass), pass along (http://wordnet.princeton.edu/perl/webwn?o2=&o0=1&o7=&o5=&o1=1&o6=&o4=&o3=&s=pass+along), put across (http://wordnet.princeton.edu/perl/webwn?o2=&o0=1&o7=&o5=&o1=1&o6=&o4=&o3=&s=put+across) (transmit information )"
So neurons and nerves transmit or pass along information, this is true.

Definition of information from http://wordnet.princeton.edu/perl/webwn?s=information:
"(n) information, info (http://wordnet.princeton.edu/perl/webwn?o2=&o0=1&o7=&o5=&o1=1&o6=&o4=&o3=&s=info) (a message received and understood)"
Taking them both together, neurons and nerves transmit or pass along a message that is received and understood. This is also true, so I think that communicate and transmit work in non-metaphorical sense.

Now if you're unsure about message working, I already described what a message is in terms of nerves and neurons, but I'll show you the definition that works.

Definition of message from http://wordnet.princeton.edu/perl/webwn?s=message&sub=Search+WordNet&o2=&o0=1&o7=&o5=&o1=1&o6=&o4=&o3=&h=00000:
"(n) message (a communication (usually brief) that is written or spoken or signaled)"
Signaled is the key here because its electrical.

-DS

[Rosa Lichtenstein]

DS, thanks for that, but several of those connotations of 'communicate' cannot apply here (e.g., "Communicating door" -- nothing is 'passed on' here), and the rest relate to the exchange of information or messages, which are typically linguistic. Neurons have no language.

The definition of 'information' is no help either, since each one of the ones your link lists seems to relate to language again.

And of course, messages can be signalled, but then in order for that to happen they have to be encoded from a language and then decoded back into one, which cannot apply to neurons, since they have no language and are not language users.

[By the way, I have studied physiology, so I do know the science; I just do not accept the unhelpful metaphors.]

[DesertShark]

DS, thanks for that, but several of those connotations of 'communicate' cannot apply here (e.g., "Communicating door" -- nothing is 'passed on' here), and the rest relate to the exchange of information or messages, which are typically linguistic. Neurons have no language.

The definition of 'information' is no help either, since each one of the ones your link lists seems to relate to language again.

And of course, messages can be signalled, but then in order for that to happen they have to be encoded from a language and then decoded back into one, which cannot apply to neurons, since they have no language and are not language users.

[By the way, I have studied physiology, so I do know the science; I just do not accept the unhelpful metaphors.]
I agree that not all of the definitions of communication, information, and message work for neurons, which is why I quoted the specific definitions that did work.

There is something 'passed on' here, an electrical signal is passed on. I think you are limiting yourself when you say that messages have to be encoded from a language and then decoded back into one. This isn't true, messages only need to be understood. A message can be a picture (with no words on it) and the image can be understood and communicated across languages without ever using words and so not using language.

I agree that there are helpful and unhelpful metaphors used a lot in science, but I do not think this is one of them. I think the definitions I provided for communication, information, and message show that they are not metaphorical here.

-DS

[Rosa Lichtenstein]

DS:


I agree that not all of the definitions of communication, information, and message work for neurons, which is why I quoted the specific definitions that did work.

Unfortunately, I could not see this.

The mere 'passing on' of something is not communicating. So, if I pass the salt to someone, that is not communicating. Indeed, if I send an electrical pulse to someone that is not communicating unless that charge has been encoded from a language, and can be decoded at the other end.

Neurons cannot do this for the reasons I suggested.


I think you are limiting yourself when you say that messages have to be encoded from a language and then decoded back into one. This isn't true, messages only need to be understood. A message can be a picture (with no words on it) and the image can be understood and communicated across languages without ever using words and so not using language.

Understanding is what we humans do; neurons cannot do this. Nor can they entertain images. And images need interpreting (they do not interpet themselves). Neurons cannot do this either.


I think the definitions I provided for communication, information, and message show that they are not metaphorical here.

On the contrary, it is quite clea that they cannot be literal, for the reasons I suggest above. [And it is not too clear how to 'cash out' these metaphors, either.]

[DesertShark]

Unfortunately, I could not see this.
I edited the post so that you can see the definitions I was using.


The mere 'passing on' of something is not communicating. So, if I pass the salt to someone, that is not communicating. Indeed, if I send an electrical pulse to someone that is not communicating unless that charge has been encoded from a language, and can be decoded at the other end.

Neurons cannot do this for the reasons I suggested.
I looked up the definition of communication on dictionary.com and almost every one of their resources includes a biological definition of communication. They can be seen here:
"7. Biology. a. activity by one organism that changes or has the potential to change the behavior of other organisms. b. transfer of information from one cell or molecule to another, as by chemical or electrical signals."
and
"Biology The transfer of information from one molecule, cell, or organism to another, as by chemical or electrical signals or by behaviors."
So I stand by the use of communication and the claim it is not a metaphor.


Understanding is what we humans do; neurons cannot do this. Nor can they entertain images. And images need interpreting (they do not interpet themselves). Neurons cannot do this either.
I never said that neurons could interpret or understand anything. I was using images as an example of one form of communication that does not involve language. Also behavior, as shown in the definitions above is a form of communication that doesn't involve language (it can, but doesn't have to). Animals don't have language and communicate all the time, so language is not necessary for communication.


On the contrary, it is quite clea that they cannot be literal, for the reasons I suggest above. [And it is not too clear how to 'cash out' these metaphors, either.]
According to the definitions they are literal.

[Rosa Lichtenstein]

DS:


I edited the post so that you can see the definitions I was using.

Yes, I know, and I think they are all susceptible to my objections.


I looked up the definition of communication on dictionary.com and almost every one of their resources includes a biological definition of communication. They can be seen here:
"7. Biology. a. activity by one organism that changes or has the potential to change the behavior of other organisms. b. transfer of information from one cell or molecule to another, as by chemical or electrical signals."
and
"Biology The transfer of information from one molecule, cell, or organism to another, as by chemical or electrical signals or by behaviors."

You must know that dictionaries are repositories of usage, and this one is clearly recording the metaphortical use by neuroscientists of the word 'communicate'.

If you look up 'God' you will see they also record the use of this word by believers, but us atheists do not accept what the dictionary says a literally true here.

The same applies when scientists/dictionaries use ordinary words non-literally.

This is, of course, quite apart from the fact that scientific and philosophical issues cannot be settled by looking stuff up in a dictionary.


I never said that neurons could interpret or understand anything. I was using images as an example of one form of communication that does not involve language. Also behavior, as shown in the definitions above is a form of communication that doesn't involve language (it can, but doesn't have to). Animals don't have language and communicate all the time, so language is not necessary for communication.

In fact you said this:


This isn't true, messages only need to be understood. A message can be a picture (with no words on it) and the image can be understood and communicated across languages without ever using words and so not using language.

This says that messages need to be "understood"; but how can neurons do this?

Now you say:


I was using images as an example of one form of communication that does not involve language.

But, understanding involves language -- unless you are using "understanding" in a metaphorical way now...

And, as I pointed out, images are not self-interpreting. Do neurons, therefore, do the interpreting? If so, they are diminutive human beings. If not, how are images interpreted?

And I deny animals communicate. Sure, they signal one another, but signalling is not the same as communicating (unless a language is involved).


According to the definitions they are literal.

Well, you have yet to explain how they are.

[DesertShark]

How the Nervous System Develops

Development is all about diffusion gradients of ligands producing different patterns of gene expression. Transcription factors are the 1st genes differentially expressed.
Gene expression -> transcription factors -> other genes -> proteins

Basic vertebrate development:
fertilization -> cleavage (totipotent stem cells), days 1-4 -> morula/blastula - blastomeres (not specified) and inner cell mass (embryonic stem cells, pluripotent), day 5 -> implantation and gastrulation - movement of blastomeres to germ layers (endoderm (gut), mesoderm (connective tissue and muscle), and ectoderm), days 6-10 -> primitive streak, days 10-14 -> organogenesis - neurulation (multipotent stem cells), days 15-24

[Quick blurb on stem cells: they're characterized by "self-renewal" and restricted gene expression; embryonic - pluripotent, somatic - multipotent.
The following are the types of stem cells and the order they are seen in development (beginning to end).
-totipotent - become anything
-pluripotent - become any cell type, but placenta
-multipotent - organ specific
-terminally differenetiated]

Basic stages of nervous system development (link (http://www.brown.edu/Courses/BI0032/stemcell/GenNDev.html) to a slightly comlex version, but good pictures):
-Induction and patterning (link (http://www.niaaa.nih.gov/NR/rdonlyres/80796551-892E-44DE-87CE-1B6935C61149/0/embryonic.gif) to image of part of this stage, link (http://www.bioethics.gov/images/sc_images/human_embryo.gif) to more complicated picture) (link (http://www.nature.com/nrn/journal/v6/n12/fig_tab/nrn1805_F3.html) to picture of spinal cord patterning)
-Neurogenesis (birth of neurons)
-Migration of neurons
-Outgrowth of neuronal processes (axon and dendrites)
-Synaptogenesis (formation of synapses and synapse elimination)
-Synaptic modification during development
-Plasticity in adulthood

Induction: primary neurulation and neural tube formation creates "organizing centers" for neural patterning (RL will probably get mad about this, so sorry for using metaphors, its just a lot easier in this case and I couldn't think of how else to explain it). The ectodrem is dorsal; the notochord is in the mesoderm and induces (by noggin and chordin, which are polypeptides) overlying ectoderm to neuroectoderm, which thickens into the neural plate by Sonic HedgeHog (SHH, protein/ligand). The neural plate turns into the neural crest and roof plate (sensory, Dorsal Root Ganglia) dorsally by TGF family and dorsalin, and the floor plate (motor) by SHH. The closing of the roof plate leads to formation of neural tube (-> ventricular system -> CNS). The neural crest, outside the neural tube becomes PNS. Now the entire NS pattern is in place (patterning - chemical cues activated by retionic acid (vitamin A)).
BMPs (Bone Morphogenetic Proteins) expressed by somites tells early cells to turn into bone; noggin and chordin sequestor BMPs inhibiting their action and preventing association with receptors.
Pluripotent stem cells -> neural precursor cells -> neuroblasts (non-renewing, post-mitotic) -> terminally differentiated neurons

There are two models of cell specification, both happen in development.
-cell lineage model: asymetrical cell division, cellular interactions dictating later specification; early events
-cellular interactions model: environment dictates differeniation; later events, after neurons send projections

Segmentation (anterior - posterior patterning of neural tube) and protein gradients:
-Hox (homeobox) genes (http://www.brown.edu/Courses/BI0032/stemcell/hdgenes.jpg) - involved in body plan segmentation and regional identity establishment in brain
*DNA binding proteins regulating gene expression
*same in hind brain (brainstem) of all vertebrates
Regional specification (segmentation) of neural tube and human brain - relates to the ventricular system
-at the end of 1st trimester the segmentation is as follows (anterior to posterior):
*prosencephalon - which will become the forebrain
*mesencephalon - which will become the midbrain
*rhombencephalon - which will become the hindbrain
*spinal cord
-at the end of 2nd trimester the segmenation is (a to p):
*telencephalon - will become cortex, contains lateral ventricles
*diencephalon - will become thalamus and hypothalamus, contains 3rd ventricle
*optic vesicle
*mesencephalon - future cerebral aquaduct
*metencephalon - becomes pons and cerebellum, contains 4th ventricle
*myelencephalon - becomes medulla
*spinal cord - contains central canal
-end of 3rd trimester you get cerebral hemispheres, central sulcus, lateral fissure, olfactory bulb, cerebellum, pons, medulla, spinal cord, and basal ganglia along with all the structures previously mentioned

Neurogenesis (sorry I couldn't find any good pictures of this) - in the G1 phase the neuronal precursor is at the neural tube lumen end of the neural ectoderm, during the S phase the neuronal precursor moves to the pial surface, during the G2 phase it moves back down to the neural tube lumen end, and during mitosis it divides. If its a symmetrical division it will continue to divide (stem cells). If its an asymmetrical divison, one will be a neuroblast and one will continue to divide until specified.
-occurs after neural tube segmentation and most is done by birth
-approximately 100 billion neurons produced and 10x more glia cells produced in late prenatal, early postnatal development
-precursors remain in ventricular zone (in low numbers) and give rise to neurons and glia

Migration
-neurons are born at different times and migrate right away
-they get help from glia cells which radiate from lumen to pial surface (anchored here with help of cajal-recia and factors released by radial glia itself)
-the soma migrates after birth getting cues from leading and trailing process on migrating cell (integins and other cell surface molecules) (leading and trailing processes become neurites then specified to axon or dendrite irreversibly)
-the brain develops in an inside-out fashion (layer 6 to layer 1), the deeper layers fill in first

Outgrowth of neuronal processes
Growth cone - specialized tip of outgrowing axon, specific to neurites, it "explores the environment with filapodia (that extend from lamellapodia)", it moves by changes in actin polymerization due to chemo-attractive and chemo-repellant cues (stablizes or collapses growth cone)
-This stage of NS development is influenced by many surface-bound factors
-growth cone and axon elongation - membrane bound cues and soluble chemo-attractive and chemo-repulsive cues (tropic mechanism)
-trophic mechanisms are target-derived factors and control of cell survival
tropism = guidance; trophism = support
neurotrophic factor hypothesis - intense competition for limited target-derived factors which promote survival and growth, the size of the target will regulate number of surviving cells

Some of the how we know:
-about migration: inject radiolabeled thymidine or thymidine analogs (radiolabeled BrDu) into cells or into bloodstream which becomes diluted overtime, therefore the higher the concentration the closer to birth; it is used because it becomes incorporated into newly synthesized DNA during the S phase. This experiment was done on pregnant monkeys and the babies were sacrificed at different times to see where cells ended up (this how they found out that the brain develops inside out).
-the growth cone was discovered in 1910
Neurotrophic factor hypothesis (soluble factor)
*Viktor Hamburger - limb bud transplant; target size matters
*Rita Levi-Montalcini - found soluble factor
*Stanely Cohen - isolated through reverse genetics (used snake venom, something in snake venom is neurotrophic)

I hope this was what you were looking for.
-DS

[DesertShark]

You must know that dictionaries are repositories of usage, and this one is clearly recording the metaphortical use by neuroscientists of the word 'communicate'.

If you look up 'God' you will see they also record the use of this word by believers, but us atheists do not accept what the dictionary says a literally true here.

The same applies when scientists/dictionaries use ordinary words non-literally.

This is, of course, quite apart from the fact that scientific and philosophical issues cannot be settled by looking stuff up in a dictionary.
Agreed, but if you are arguing semantics then I feel a dictionary is the only way to clear things up. Could you provide definitions of the words being discussed? Since you don't want to use dictionary definitions of the words, I'd like to know how you define them. And if it turns out that we are just defining the words in different ways, there really isn't an argument any more, just a different understanding of a word's meaning. I say there is no argument any more because you don't want to use a dictionary as a neutral source for the definition and as I said, the issue then is just a difference in understanding of a word's meaning. Which honestly, I don't know how to clear up without a dictionary. It seems that the argument would just keep going back and forth with no end in sight.


In fact you said this:



This says that messages need to be "understood"; but how can neurons do this?

Now you say:



But, understanding involves language -- unless you are using "understanding" in a metaphorical way now...
Using "understood" was a poor word choice on my part.


And, as I pointed out, images are not self-interpreting. Do neurons, therefore, do the interpreting? If so, they are diminutive human beings. If not, how are images interpreted?
Images don't have to be interpreted in a language to be understood. Babies can look at pictures and respond to them and they lack language. Also, babies (who lack language) still communicate.


And I deny animals communicate. Sure, they signal one another, but signalling is not the same as communicating (unless a language is involved).
Wow. I'd like to hear more about this, but that should be in a different thread. Do you also deny babies communicate? If so, what age does communication happen in humans?


Well, you have yet to explain how they are.
I felt the definitions did that. I don't think that your objections apply to them. Transmitting information is a form of communication (by the definitions I used) and neurons/nerves do this, transmit information. Information can be stored in many forms, in this case as an electrical signal.

I feel that this semantics argument does not have a place under this thread and should perhaps be moved to a different thread as to not take away from the discussion of the topics at hand.
-DS

[Rosa Lichtenstein]

DS:


Agreed, but if you are arguing semantics then I feel a dictionary is the only way to clear things up. Could you provide definitions of the words being discussed? Since you don't want to use dictionary definitions of the words, I'd like to know how you define them. And if it turns out that we are just defining the words in different ways, there really isn't an argument any more, just a different understanding of a word's meaning. I say there is no argument any more because you don't want to use a dictionary as a neutral source for the definition and as I said, the issue then is just a difference in understanding of a word's meaning. Which honestly, I don't know how to clear up without a dictionary. It seems that the argument would just keep going back and forth with no end in sight.

I am not arguing 'semantics'; that is what you are doing. In reply, I merely point out that none of these 'definitions' can be taken literally.

And, I have not tried to define these words, nor would I. I, like you, understand the English language. If one of us is using words in an odd sort of way (which seems to imply that neurons can think and/or interpret one another), then that needs pointing out.

The only time I would use a dictionary is to look up a word I had never encountered before, not one that I already knew how to use.

I know how to use 'talk', 'communicate', 'understand', 'message', etc.


Using "understood" was a poor word choice on my part.

So, what do you propose to use in its place?

You see how our shared grasp of this word has made you revise what you wanted to say. What I am trying to do is appeal to that shared comprehension -- but in relation to the other words you want to appropriate.


Images don't have to be interpreted in a language to be understood. Babies can look at pictures and respond to them and they lack language. Also, babies (who lack language) still communicate.

Well, we do not know what babies do with pictures, or how they receive them. Moreover, reacting to a visual stimulus is not the same as having something communicated. If it were, then the knee-jerk reflex would be part of our communicative repertoire.

If an image is to communicate something meaningful, it has to be interpreted; otherwise nothing has been communicated. And, we use language to do that.

Otherwise, you would not be able to say what had been communicated to a baby. On the other hand, if you wanted to say what had been communicated to a baby, then you would have to use language to do that. Babies can't tell us. But then, you would only be guessing, and your guess would be misleading. And that is because that guess will be based on a sophisticated knowledge of language, which a baby hasn't got. Indeed, it has no language.


I'd like to hear more about this, but that should be in a different thread. Do you also deny babies communicate? If so, what age does communication happen in humans?

Yes, I deny babies can communicate.

And there is no set age at which they begin. They are slowly socialised into a community of speakers, and when they have mastered enough of the language, they can begin to communicate.


I felt the definitions did that. I don't think that your objections apply to them. Transmitting information is a form of communication (by the definitions I used) and neurons/nerves do this, transmit information. Information can be stored in many forms, in this case as an electrical signal.

Well, as I pointed out, each of them, if interpeted literally, had untoward implications, suggesting either that neurons were human beings, or that they were enaged in conversation with one another. The only way out of that hole is to treat these words non-literally, and then, in that case, they will cease to have a clear meaning.

For example, 'information' implies a language, unless you are using this word in a technical sense (from information theory, say). But, in that case, 'communication' cannot be literal, and neither can 'message'.

But, if this is so, then we really do not yet know what you mean by this odd use of language. What is the non-literal meaning of "message"? I am sure I do not know.

It's a bit like being told 'god' is a 'spirit' -- but wtf does that mean?

Or that a positron is an electron travelling 'backwards in time'. Wtf does that mean? The word 'travelling' (or the word 'time') is non-literal here. But then what is the non-literal meaning of 'travelling'?

Science is shot-through with metaphor, and it is not too clear what any of it means.

[jake williams]

I hope this was what you were looking for.
-DS
First off, thank you so much. It won't let me give you any more rep for awhile.

It's some good background (insofar as I understand it, which isn't much), but the specific thing I want to know about (I think, again my understanding is rough) is, for one, how much of our brain is genetically determined, and second, how is it genetically determined. Take Chomsky's example of there being a "language organ" in the brain - some specific neural structures which allow for the specific development of language. How would this structure work, and how would genes control the development of it?

My knowledge of biology is arse and I know I might not be asking the right "type" of question, but I'm trying.

[Comrade Phil]

Here's something to think about..
Two neurons can not communicate with one another, they merely provide a means for electrical and chemical stimuli to move down a neural pathway. However, specific cellular activities occur in reaction to specific stimuli (ie. frequncy/intensity of action potentials, reception of different neurotransmitters). Clearly not an interpreted language, rather a set of defined occurences.
Human beings do communicate with one another using language. However, in order to produce, comprehend, intepret, and asscociate language, human begins require a vast array of neurons. (eg. remove Brocas's area of the cortex and the mind can no longer comprehend language) A single neuron is just a useless biological machine, but gather billions of them them together arranged in a specific manner and one has a network which reacts to all electrical, chemical and environmental stimuli with such complexity and specificity that the illusion of a unified being is created.

Consciousness, language, emotion, etc, all run parallel to the billions of cellular reactions taking place in the nervous system.Take the example of the television with a picture of Karl Marx on it. View the television with a broad perspective, you have a unified image of Marx with a subjective meaning. View the television with a narrow perspective, you have an array of coloured pixels with no meaning. Change a pixel(s) and you change the subjective meaning of the picture. Change the subjective perception of Marx's picture and you change the value of each pixel in the narrow perspective. This same situation applies to mental events (broad perspective) and neural events (narrow perspective). Change in the cellular activity of one's neurons (eg. drugs, neural stimulation (I smell burnt toast Dr. Penfield!!:D) ) and one observes change in one's mental perception/cognitive abilities. However, the cellular events in your nervous system will change in accordance with mental percetion and cognitive tasks, as is demonstrated by psychological experiments with MRIs and other imaging technologies. Mind and body are clearly united.

So obviously two nerve cells cannot communicate with one another, but two conscious sentient beings can (eg humans). However, consciousness and sentience cannot exist without the nervous system. So are the two conscious sentient beings communicating or are the two networks of neurons communicating?both? Can the neural networks be considered conscious/sentient??:blink:

[Rosa Lichtenstein]

Comrade Phil:


So are the two conscious sentient beings communicating or are the two networks of neurons communicating? both? Can the neural networks be considered conscious/sentient??

If to be 'conscious and sentient' is to have a neural network, then, if we are to describe a neural network as 'conscious and sentient', that neural network would have to have its own neural network!

On the other hand, if you want to say that neural networks can be 'conscious and sentient' without their having their own neural network, then we can say the same about human beings.

There are two basic difficulties with all attempts to solve the 'problem' of consciousness:

1) This 'problem' is a hang-over from the Platonic/Christian/Cartesian (hence, ruling-class) tradition that sees 'consciousness' as in internal and private affair (of the soul); a gift of 'god'. In that case, there is no 'problem' of 'consciousness', since there is no such thing as 'consciousness'. Sure, there are conscious human beings, but that is a behavioural, not a private and internal, trait.

2) Any attempt to 'solve' this 'problem' will ultimately have to attribute to internal processes, brain states or neural networks the very things that were supposed to be explained by them: i.e., human traits. Often these appear in a disguised form as inappropriate metaphors. That is why Desert Shark is having such a hard time explaining what he means without the use of such metaphors. It also shows why your attempt faced the re-duplication problem.

Alas, there is no way out of this 'difficulty'. And that is because it is based on a Platonic/Christian/Cartesian myth, and so it is not a scientific problem which needs solving -- despite the fact than most scientists think that it is. [This is in fact one of the ruling ideas that always rules.] It is not possible to 'solve' a mythical 'problem', any more than it is possible to solve a non-existent puzzle.

[Comrade Phil]

If to be 'conscious and sentient' is to have a neural network, then, if we are to describe a neural network as 'conscious and sentient', that neural network would have to have its own neural network!

On the other hand, if you want to say that neural networks can be 'conscious and sentient' without their having their own neural network, then we can say the same about human beings.

Ya got me there. I totally overlooked this re-duplication problem.



1) This 'problem' is a hang-over from the Platonic/Christian/Cartesian (hence, ruling-class) tradition that sees 'consciousness' as in internal and private affair (of the soul); a gift of 'god'. In that case, there is no 'problem' of 'consciousness', since there is no such thing as 'consciousness'. Sure, there are conscious human beings, but that is a behavioural, not a private and internal, trait.

I certainly wasn't proposing any sort of mind-body dualism. There is no evidence to support this theory.



2) Any attempt to 'solve' this 'problem' will ultimately have to attribute to internal processes, brain states or neural networks the very things that were supposed to be explained by them: i.e., human traits. Often these appear in a disguised form as inappropriate metaphors.

I don't think that one can attribute neural events to mental events, or vice versa. There are no definite means to prove this. As stated above, change in neural physiology changes consciousness, but also, change in consciousness changes neural physiology. To me, that suggests that these two observations are the same entity. The distinction is created from whether one percieves this entity through objective analysis (neural) or subjective experience (mental).



...it is not a scientific problem which needs solving -- despite the fact than most scientists think that it is.

This may be true. However, without such problems in mind, I think it is very easy for science students, neuroscientists and psychologists to slip into very arrogant and often false mindsets (like the metaphor problem. I hadn't realized how prevalent it was in textbooks and lectures.) It is a shame that there is little to no requirement for science students to address the relevant philosophical issues.

[Rosa Lichtenstein]

Phil:


I certainly wasn't proposing any sort of mind-body dualism.

Indeed, but the words you use (or at least the metaphors) are a carry-over from that tradition.

Here is another example:


As stated above, change in neural physiology changes consciousness, but also, change in consciousness changes neural physiology. To me, that suggests that these two observations are the same entity. The distinction is created from whether one percieves this entity through objective analysis (neural) or subjective experience (mental).

This is a prejudicial use of the word 'consciousness', which is a carry-over from the Platonic/Christian/Cartesian tradition -- as I noted in my previous post.


However, without such problems in mind, I think it is very easy for science students, neuroscientists and psychologists to slip into very arrogant and often false mindsets (like the metaphor problem. I hadn't realized how prevalent it was in textbooks and lectures.) It is a shame that there is little to no requirement for science students to address the relevant philosophical issues.

Good luck trying to get them even to recognise this problem!

After all: the ruling ideas are always those of the ruling class -- even here.

Indeed, most comrades too find this almost impossible to accept.

[DesertShark]

RL:
We are together in a semantic argument, which is why I asked you to define your words or at least say what definition you were using or had in mind during this discussion. You are arguing that communication only occurs through language, which is a particularly narrow definition of communication. I am arguing that communication has a broader definition and under this broader definition some cells, some non-human animals, and babies communicate. That is why this is a semantic argument (definition of semantic: of, pertaining to, or arising from the different meanings of words or other symbols).

You deny animals communicate, but we (humans) are animals. You also deny that babies communicate. What about when your baby cries when it is hungry? Is that not a form of communication? Your baby has a different cry when its diaper needs to be changed, and a different cry when it is in pain. Any mother (or anyone who spends a lot of time with one particular baby) will tell you that babies have different cries for different things that they need/want, which the caretaker responds to and they (babies) do this without language. Please explain how that is not a form of communication (outside of the lack of language aspect). In addition (in regards to non-human animals), your dog let's you know when it needs to go outside, come back in, or when it is hungry or thirsty. Please explain how that is not a form of communication (again, outside of just the lack of language aspect). Honey bees do a waggle dance to show other bees in their hive where a new food source is, how is that not communication? (If you don't know what a waggle dance is you can see it here: http://www.youtube.com/watch?v=-7ijI-g4jHg. If you want to know how we know, you can see it here in an experiment: http://www.youtube.com/watch?v=ywdTfEBVcSY&feature=related and if you want to know what the dance means to other bees: http://www.youtube.com/watch?v=4NtegAOQpSs&feature=related)

Within our own form of communication it has at least 3 parts: body language, voice tonality, and words (language). According to this study [Mehrabian and Ferris,'Inference of Attitude from Nonverbal Communication in Two Channels' in The Journal of Counselling Psychology Vol.31, 1967,pp.248-52] over half (about 55%) of what's being communicated comes from body language and only 7% from the actual words being used (the rest from tonality). Non-verbal communication plays a larger role in communication then words do (ie language). Animal communication is defined as any behavior on the part of one animal that has an effect on the current or future behavior of another animal, as humans our form of verbal communication (dialogue) is just a more developed aspect of this.

There are many types of communication, only one of which uses language, but communication is not limited to just language use. Dialogue is one type of communication (the one you seem to believe is the only type of communication), which involves a reciprocal conversation between two or more entities. There's also non-verbal communication: gestures, body language, facial expressions, eye contact, posture, etc.

Communication is the exchange of information between living entities, in other words the transmission of signals involving a living sender and receiver. Biology (the study of life/living things) defines life as the following: highly organized structure, displays homeostasis (maintaining a relatively constant internal environment dispite a changing external environment), reproduce themselves (pass on genetic information), grow and develop from simple beginnings, take energy and matter from the environment and transform it, respond to stimuli, and show adaptation to their environment (evolution). So for something to be considered living it has to display all of those characteristics. Any biology textbook you look at will say that a cell is the smallest unit of life because it does all of those things mentioned above. Viruses are therefore not a living organism because they cannot reproduce on their own (they need a host to reproduce).

You said:

And of course, messages can be signalled, but then in order for that to happen they have to be encoded from a language and then decoded back into one, which cannot apply to neurons, since they have no language and are not language users.
Messages don't have to be encoded and decoded from and to a language. They just have to be converted from one form to another, and this happens between cells. When you talk to someone on the phone (specifically in this example, by a landline), the sound waves are converted to electrical signals that travel over a phone wire. This process of converting the message from one form to another is called signal transduction.
The following is a description of this process from a college level cell biology textbook.
"In a typical communication between cells, the signaling cell produces a particular type of signal molecule that is detected by the target cell. The target cells possess receptor proteins that recognize and respond specifically to the signal molecule. Signal transduction begins when the receptor protein on the target cell receives an incoming extracellular signal and converts it to the intracellular signals that alter cell behavior. (...) Single cells and cells in multicellular organisms use hundreds of kinds of extracellular molecules to send signals to one another - proteins, peptides, amino acids, nucleotides, steroids, fatty acid derivatives, and even dissolved gases - but they rely on only a handful of basic styles of communication for getting the message across." (Alberts et al. Essential Cell Biology. New York: Garland Science, 2004. p534) Four basic styles: Endocrine- act widely through the body, Paracrine- act locally, Neuronal (already described in this thread), and Contact-Dependent- membrane to membrane interface.
“A typical cell in a multicellular organism is exposed to hundreds of different signal molecules in its environment. These may be free in the extracellular fluid, embedded in the extracellular matrix in which cells rest, or bound to the surfaces of neighboring cells. Each cell must respond selectively to this mixture of signals, disregarding some and reacting to others, according to the cell’s specialized function. Whether a cell responds to a signal molecule depends first of all on whether it possesses a receptor for that signal. (…) By producing only a limited set of receptors out of thousands that are possible, the cell restricts the types of signals that can affect it. But this limited range of signals can still be used to control the behavior of the cell in complex ways. The complexity is of two sorts. First, one signal, binding to one type of receptor protein, can cause a multitude of effects in the target cell: it can alter the cell’s shape, movement, metabolism, and gene expression. …[T]he signal from a cell-surface receptor is generally conveyed into the cell interior via a set of interacting molecular mediators that are capable of producing widespread effects in the cell. This intracellular relay system and the intracellular targets on which it acts vary from one type of specialized cell to another, so that different types of cells respond to the same signal in different ways. (…) The second kind of complexity arises because a typical cell possesses a collection of different receptors – tens to hundreds of thousands of receptors of a few dozen types. Such variety makes the cell simultaneously sensitive to many extracellular signals. These signals, by acting together, can evoke responses that are greater than the sum of the effects that each signal would evoke on its own. The intracellular relay systems for the different signals interact, so that the presence of one signal modifies the responses to another. Thus one combination of signals might enable a cell to survive; another might drive it to differentiate in some specialized way; and another might cause it to divide. In the absence of any signals, most animal cells are programmed to kill themselves [apoptosis]. Because the execution of such a complex program often requires the synthesis of new proteins, it might take the cell hours to fully respond to incoming signals. Overall, the integration of extracellular cues allows a relatively small number of signal molecules, used in different combinations, to exert subtle and complex control over cell behavior. (Alberts et al., p536-538)
[Side note: A cell can also change the amount of receptors on its surface based on the amount of stimulus it is receiving.]

You may have problems with the word recognize. But like almost every word, there’s not just one sole meaning. Recognize alone has anywhere from 2 to 11 definitions depending on the dictionary you use; information and communication both have 2 to 8 and some of these have multiple parts. Even the word “god” has anywhere from 2 to 10 definitions, some with multiple parts. As an atheist you may not agree with all the definitions of the word, but there is at least one that you agree with and knowing the other definitions is beneficial because it allows you to communicate with people who do not hold your beliefs and understand what they mean when they use the word. Keeping yourself to a single understanding of every word limits your ability to communicate effectively with a diverse audience and limits your ability to understand what it trying to be communicated to you. I do not restain my dictionary use only to words I do not know the meaning of because I may not fully understand all the uses of or meanings of words I already know. Language is no where near my strong suit and in all honesty I hate semantics and language because they are limiting in one’s ability to communicate. I also hate semantics because it leads to discussions like the one we’re having, which I feel are relatively pointless especially when the idea trying to be shared, has been effectively communicated.

RL and CP:
To fix the problem of metaphors in science, would you want scientists to create new words to describe the things they find? If so, wouldn’t this create a problem in the ability of a scientist to communicate their findings to any individual not in the scientific community? Wouldn’t this also create problems in learning about science in schools because a whole new language would have to be learned along side it? Things like this are already a problem today. Don’t most people have problems understanding exactly what’s going on with their illness and what’s happening to their body because their doctors use medical jargon? What about individuals who have problems defending themselves in court because they lack legal jargon? The creation of more scientific jargon would only lead to an increased elitism making things that could easily be understood by anyone, inaccessible to the common person.


-DS (not a he, but a she)

[DesertShark]

First off, thank you so much. It won't let me give you any more rep for awhile.

It's some good background (insofar as I understand it, which isn't much), but the specific thing I want to know about (I think, again my understanding is rough) is, for one, how much of our brain is genetically determined, and second, how is it genetically determined. Take Chomsky's example of there being a "language organ" in the brain - some specific neural structures which allow for the specific development of language. How would this structure work, and how would genes control the development of it?

My knowledge of biology is arse and I know I might not be asking the right "type" of question, but I'm trying.

No worries :] I'm always happy to share what I know about biology. Thank you for the rep points.

I'm pretty sure that all the physical aspects of our bodies are genetically determined, but that's not to say that environmental factors and random mutations didn't play a role in the changing of genetic information. So the physical structure of our brain is genetically determined and is relatively consistent throughout the mammalian world (check out this picture (http://en.wikipedia.org/wiki/Image:ComparitiveBrainSize.jpg) to see how similar brains look).

The connections between neurons are environmentally (maybe a little bit genetically) determined throughout our lives. We are constantly bombarded with stimuli and we filter a lot of it out, that filtering is a changing in connections by creating new connections, increasing/decreasing the number of connections any given neuron has, or completely eliminating connections altogether (this would kill the cell). Babies' filters are not as refined as ours and taking psychedelic drugs (such as LSD and mescaline) temporarily reduces the brain's filtering. That saying "if you don't use it, you lose it" is true in the case of brains. A person who becomes blind will end up with a reduced occipital lobe and an increased auditory cortex (found in the temporal lobe) or other part of the brain. Babies and children have a higher brain plasticity then adults, which is why they bounce back more easily if they lose one of their senses (like that boy who lost his eyes to cancer and now uses echolocation to get around (http://www.cbsnews.com/stories/2006/09/06/eveningnews/main1977730.shtml)).

If you want to know how specific structures arise in the brain, I guess the best way to understand that would be to look at how the brain evolved. [A cool thing they are finding is that embryonic development follows evolutionary development; a simple example: at some point in the womb you had a postanal tail and then lost it, over the course of vertebrate evolution we had a postanal tail and lost it (this works with gills/pharyngeal slits and some other things, but it doesn't work for everything (like scales and fur)).] The brains of invertebrates are very different from vertebrate brains and I don't know really anything about them, so I'll only be talking about vertebrate brains. All vertebrate brains (http://www.colorado.edu/intphys/Class/IPHY3730/image/figure5-4.jpg) share a common underlying form.

Some characteristics that deal with the central nervous system, starting from just before vertebrate and going through to mammals:
-The dorsal hollow nerve cord is a shared characteristic ofhemichordates (ex. acorn worms and pterobranchs) and chordates. The earliest fossil evidence of hemichordates is the Yunnanozoan lividum (dated 540-560 Mya). The dorsal hollow nerve cord becomes the brain and spinal cord farther down the evolutionary chain.
-Neural crest cells, sense organs (for vision, audition/change in water pressure, and chemorecption/olfaction), cranium, and tripartite brain (forebrain, midbrain, and hindbrain [- showed when they arise in embryonic development in earlier post]) are shared characteristics of all Craniates (last common ancestor of Myxinoidea (hagslimes) and vertebrates). Also, a 2 chambered heart shows up, which is controled by the brain. Fossil Hagslimes: Myxinikela/Gilpichthys (330 Mya).
-Cerebellum, pineal organ (circadian rhythm, photosensitive), 2 semi-circular canals (gives orientation in space, can now gauge roll and pitch), and a lateral line system are shared characteristics of Petromyzontoidea (lampreys) and Gnathostomata (jawed vertebrates).
-3 semi circular canals is a shared characteristic of all Gnathostomes.
-Corpus callosum (connects right and left cerebral hemispheres) is a shared characteristic of all placental mammals. The neopallium is present in mammals and some reptilians, it is an area of gray matter of the brain. It's an association center that receives fibers that relay sensory stimuli from the brain stem and send "commands" directly to the motor centers of the brain. In mammals, the cerebral hemispheres are extremely enlarged (partially due to the expansion of the neopallium).

Keep asking questions!
DS

[Rosa Lichtenstein]

DS:


We are together in a semantic argument, which is why I asked you to define your words or at least say what definition you were using or had in mind during this discussion. You are arguing that communication only occurs through language, which is a particularly narrow definition of communication. I am arguing that communication has a broader definition and under this broader definition some cells, some non-human animals, and babies communicate. That is why this is a semantic argument (definition of semantic: of, pertaining to, or arising from the different meanings of words or other symbols).

As I indicated, words that we know how to use do not need defining -- otherwise you would need a definition of 'definition', and of 'word'.

And my argument that it is only in language that communication occurs is indeed correct, since it is not possible to say, short of descent into metaphor, exactly what is communicated except by the use of language.


You deny animals communicate, but we (humans) are animals

Well, the question was about non-human animals, so this is not a significant point.


You also deny that babies communicate. What about when your baby cries when it is hungry?

A baby is not communicating, but crying. A mother does not say 'Oh dear the baby has been communicating all morning! I can't get her to shut up!'.


Your baby has a different cry when its diaper needs to be changed, and a different cry when it is in pain. Any mother (or anyone who spends a lot of time with one particular baby) will tell you that babies have different cries for different things that they need/want, which the caretaker responds to and they (babies) do this without language. Please explain how that is not a form of communication (outside of the lack of language aspect). In addition (in regards to non-human animals), your dog let's you know when it needs to go outside, come back in, or when it is hungry or thirsty. Please explain how that is not a form of communication (again, outside of just the lack of language aspect). Honey bees do a waggle dance to show other bees in their hive where a new food source is, how is that not communication?

The baby stuff is anecdotal, but even if it weren't, the baby is not communicating since it is not a language user. If a mother chooses to interpret her baby in a certain way, she, as a language user, can do that. But, what she can't do is attribute to a baby the thought "My nappy is wet" since babies do not know about nappies.

The same is true of the other examples you give: we use language to help express what we see, but there is no way that a bee, for example, has the thought "The food source is 200 metres due east." Bees do not know about the compass.


Within our own form of communication it has at least 3 parts: body language, voice tonality, and words (language). According to this study [Mehrabian and Ferris,'Inference of Attitude from Nonverbal Communication in Two Channels' in The Journal of Counselling Psychology Vol.31, 1967,pp.248-52] over half (about 55%) of what's being communicated comes from body language and only 7% from the actual words being used (the rest from tonality). Non-verbal communication plays a larger role in communication then words do (ie language). Animal communication is defined as any behavior on the part of one animal that has an effect on the current or future behavior of another animal, as humans our form of verbal communication (dialogue) is just a more developed aspect of this.

You are confusing signalling with communication (and so are those who did the study you mention). [Same comment applies to the Bees example.]


There are many types of communication, only one of which uses language, but communication is not limited to just language use. Dialogue is one type of communication (the one you seem to believe is the only type of communication), which involves a reciprocal conversation between two or more entities. There's also non-verbal communication: gestures, body language, facial expressions, eye contact, posture, etc.

Communication is the exchange of information between living entities, in other words the transmission of signals involving a living sender and receiver. Biology (the study of life/living things) defines life as the following: highly organized structure, displays homeostasis (maintaining a relatively constant internal environment despite a changing external environment), reproduce themselves (pass on genetic information), grow and develop from simple beginnings, take energy and matter from the environment and transform it, respond to stimuli, and show adaptation to their environment (evolution). So for something to be considered living it has to display all of those characteristics. Any biology textbook you look at will say that a cell is the smallest unit of life because it does all of those things mentioned above. Viruses are therefore not a living organism because they cannot reproduce on their own (they need a host to reproduce).

Information is communicated by language -- unless you are using 'information' again metaphorically, or in a technical sense.

If the latter, then you must be using 'communicate' in a technical sense too. In that case, all you will have done is address 'communication' and not communication, and we are no further forward.

And all the examples in the world drawn from right across the sciences cannot alter this fact -- so I do not know why you keep rehearsing all that scientific detail, much of which I already know.


Even the word “god” has anywhere from 2 to 10 definitions, some with multiple parts. As an atheist you may not agree with all the definitions of the word, but there is at least one that you agree with and knowing the other definitions is beneficial because it allows you to communicate with people who do not hold your beliefs and understand what they mean when they use the word. Keeping yourself to a single understanding of every word limits your ability to communicate effectively with a diverse audience and limits your ability to understand what it trying to be communicated to you. I do not restain my dictionary use only to words I do not know the meaning of because I may not fully understand all the uses of or meanings of words I already know. Language is no where near my strong suit and in all honesty I hate semantics and language because they are limiting in one’s ability to communicate. I also hate semantics because it leads to discussions like the one we’re having, which I feel are relatively pointless especially when the idea trying to be shared, has been effectively communicated.

In fact, I reject all of the definitions of 'god' as empty.

Once more, dictionaries are only of use with words we have never seen before. They are if no use in helping us with words we already know how to use fully.

With respect to your point about 'not fully understanding a word', then my previous comment still applies. Moreover, dictionaries record the use of typographically similar words that have radically different meanings and uses. In that sense, they can be of some use if we are not fully aware of those different meanings. But here you have different words too, not one word with different connotations. So, in one area "recognise", for example, will be used in its ordinary sense. In another, in a technical sense.

In that case, any examples of the use of "recognise" that are of the latter sort cannot revise or affect our use of the former.

Once more, if this is so, the examples you give plainly relate to the use of 'recognise' in its technical sense, not recognise as we use ordinarily use it.

So, it's not much use you quoting dictionaries at me. They are not in general normative.


To fix the problem of metaphors in science, would you want scientists to create new words to describe the things they find? If so, wouldn’t this create a problem in the ability of a scientist to communicate their findings to any individual not in the scientific community? Wouldn’t this also create problems in learning about science in schools because a whole new language would have to be learned along side it? Things like this are already a problem today. Don’t most people have problems understanding exactly what’s going on with their illness and what’s happening to their body because their doctors use medical jargon? What about individuals who have problems defending themselves in court because they lack legal jargon? The creation of more scientific jargon would only lead to an increased elitism making things that could easily be understood by anyone, inaccessible to the common person.

The way science is taught in school is that students are taught new, technical terms (among other things!), some of which look like ordinary words.

Later, some of those who have learnt enough of their particular science try to write popularisations for the general public -- but they almost invariably forget that they are using technical terms, and imagine they are using ordinary words. [Sometimes they remember this, and put the words they are using in 'scare' quotes -- as if that helps!] Hence confusion soon arises.

Examples of these are 'communicate', 'code', 'map', 'wave', 'information', 'thought', 'mind', 'time', 'memory', 'emotion'...

There is in fact no way round this -- as I indicated in an earlier post. Popularisations of science cannot fail to be misleading.

Many of the so-called 'paradoxes' of 'time travel', for example, are based on just this sort of confusion. The idea that computers can 'think' is another.

The other examples you give (from medicine, or the law for instance) are not apposite, since several of the technical words used there have entered ordinary discourse. Where this happens, communication between experts and the general public is possible.