brain terminology question - association areas?

RabbitWho

Müller's law seems to differ from the modern statement of the law in one key way. Müller attributed the quality of an experience to some specific quality of the energy in the nerves. For example, the visual experience from light shining into the eye, or from a poke in the eye, arises from some special quality of the energy carried by optic nerve, and the auditory experience from sound coming into the ear, or from electrical stimulation of the cochlea, arises from some different, special quality of the energy carried by the auditory nerve. In 1912, Lord Edgar Douglas Adrian showed that all neurons carry the same energy, electrical energy in the form of action potentials. That means that the quality of an experience depends on the part of the brain to which nerves deliver their action potentials (e.g., light from nerves arriving at the visual cortex and sound from nerves arriving at the auditory cortex).

(http://en.wikipedia.org/wiki/Law_of_...nerve_energies)


What do you call the parts of the brain to which nerves deliver their action potentials?

"áreas de proyección corticales” which is literally "cortical projection areas" but I can't find that anywhere. Could it be "association areas" ?

Pythagorean

I don't think they're referring to a particular part of the brain. All parts of the brain get action potentials delivered to them (except the peripheral sensors of course, which receive stimuli from the environment/body). I think they're just saying that the experience is location-dependent in general. Association areas are part of the cerebral cortex.

RabbitWho

Sorry I didn't explain the question properly. I am okay with that part of the theory I just need the term. I should maybe have said "what do you call the type of part of the brain" instead. Is that right? Association areas are the things I described or they aren't?

Maybe I haven't understood it at all and I just think I have. I was originally just looking for a translation because my book is in Spanish.

Pythagorean

Association areas are the outer layer of cortex. Here's the major parts of them and their associated funcitonality

occipital lobe - vision
temporal lobe - audio and semantics
parietal lobe - sensation and spatial awareness
frontal lobe - planning, prediction, abstract thought.

Not sure if I'm answering your question. If not, maybe try starting from the top, asking it a new way.

RabbitWho

So they're not what I'm looking for? Isn't there a term in English for any area which gets an action potential delivered to it?


Contemporary neurophysiology refuted Muller's ideas. With the discovery of the "áreas de proyección corticales" it was confirmed that different areas of the brain can manifest different qualities of one stimulus.

Original notes (from another student):
Neurofisiologia contemporánea: Refutó las ideas de Müller. Con el descubrimiento de
las “áreas de proyección corticales” se confirma que distintas áreas del cerebro pueden
manifestar diferentes cualidades de un mismo estímulo

To me it seems odd that it's "different qualities of the same stimulus" it seems more like it interprets the same stimulus in a different way, but that's 6 of one half dozen of another.

zoobyshoe

I'm fairly sure what that refers to is the fact different areas of the brain process different aspects of what we lump together as a "sense". Different aspects of vision, most notably, are processed in different parts of the brain. Color, for example, is processed in a different place than motion. Spatial orientation is processed in the parietal lobes: damage to certain parts of the parietal lobes can cause an object you're trying to focus on to be rotated or even completely inverted. All these separate aspects of vision (or any sense) are probably what the author means by "different qualities of the same stimulus".

Pythagorean

OP may be looking for afferent (as opposed to efferent)

Psych101

I added the following part:

gustatory (taste) functions.
See the picture in the link below


http://virtual.yosemite.cc.ca.us/rdr...04_labeled.jpg


and

initiating motor activities which are sent from the Motor Homunculus of the Precentral Gyrus through the Central Fissure.

See the picture in the link below

http://ionphysiology.com/dabnm/S9781...4-014-f005.jpg

I hope the above information was useful. :)
I just took a course in Biopsychology, so this was a very fun way to review the information and help other people.

By the way, I was never aware of this "Law of Specific Nerve Energies" theory. Thanks for informing me on that.

Pythagorean

Well now it's all imbalanced. Now you have to go into more detail with the other lobes and give their relevant pathways. I'm particularly fond of somatosensory regions in the parietal cortex if you want to start there.

Psych101

Here's an interesting fact from one of my textbooks. Page 179 of Chapter 7 of Biopsychology by John Pinel says in the "Check It Out" activity the following interesting fact:

The human back takes up such a small cortical area on the somatosensory Motor Homunculus (relative to its skin surface area) that your back (from the Thoracic region all the way down to the Sacral region) is extremely insensitive to touch.

Try the following experiment: have somebody's look straight ahead. Then touch their back with anywhere from one to five fingers. Can they actually tell how many figures you touched their back with? Nope because touching them with anywhere from one to five figures will feel exactly the same. (Unless of course they are lucky and somehow guess the correct number of fingers you just touched their back with, you will notice this is most people).

I don't know very much about statistics or probability yet (haven't taken those courses yet), so my intriguing question would be this:
What are the chances of the test subject being able correctly tell how many fingers you touched their backs with given that they can only guess?

Would they only have a one in five chance of getting it correctly (since there are five different numbers of fingers to choose from)? Or I am missing something here?

Pythagorean

We did a slightly different experiment in our neurobiology class. We used the forearms and two fingers. For each trial, you separate the fingers more and more. Once the subject can tell there are two fingers, you have found the approximate size of your perceptive field for your arm.

RabbitWho

I know that, are you saying there is no single word for this in English?

It's like I came here asking how to say "música" in English and everyone describes music to me in great detail without using the word music.

RabbitWho

I was really impressed by that but then I tried the same thing with other parts of my body, including the lips which seem to me to have a really large amount of space, and unless the fingers were put on individually I couldn't count them either.

Psych101

I am also quite surprised that the cortical magnification for your eyes are disproportionately small compared to the amount of perceived sensitivity your eyes have. I mean I find violent media which features eye-gouging to be the most disturbing and disgusting. Hell, anything that even threatens my eyes i.e. a pin that's put right next my eyes (or watching a very sharp object very close to somebody's eyes whether in a documentary or film) just completely freaks me out. I wonder if any of you guys ever feel this eery sensitivity to perceived and anticipated pain derived from any stimuli coming in close contact to either your own or other people's eyes.

Even though textbooks say that the fingers are the most tactile sensitive, I beg to differ based on my personal experience. Rather I think my eyes are much more tactile sensitive than any other part of the body. Maybe this is more of a conditioned or instinctive fear rather than due to any cortical magnification or receptor field phenomenon.

Anyhow I found this conversation to be superbly interesting. Let's continue this discussion, and hopefully we can come up with an answer to each of our tantalizing questions.

Pythagorean

tactile sensitivity isn't really how much it hurts. It's a measure of the resolution of different pressures (how many different grades of pressure you can detect). But with your eye, everything hurts! So it's not really a good pressure sensing instrument like the fingers are.

zoobyshoe

I don't think there's a set term for what was described because the phenomenon discovered by Adrian was alluded to by Wiki to refute a purely speculative mechanism suggested by Muller. You could coin a term: "mono-energetically exited experientially dedicated neuronal populations" or some such, but it's not necessary to encapsulate what happens in a term intended to forever refute or rule out the speculative mechanism proposed by one obscure thinker on the subject. In other words: I never heard of Muller before you mentioned him and therefore never needed a non-mullerian term for how it works.

RabbitWho

I know! I can't figure out why I had to learn about Muller when he was completely wrong and his theory has no baring on modern psychology at all. (I mean at least Freud for example was wrong about most things, but hugely influential!)
Gosh dang you Spanish curriculum!


Thanks.