Sat Dec 8, 2012, 11:19 PM
Jim__ (10,259 posts)
Do brain cells need to be connected to have meaning?
The title of this article is, I think, a little bit misleading. The article actually discusses a paper by Asim Roy in which he supports a localist model of the brain, that is, a model where a single neuron represents a high-level concept - such as a dog. The article also contains criticism of his views by David Plaut and James McClelland. The different points of view expressed by these 3 people give some idea of the complexity involved in trying to decipher how the brain processes information.
A short excerpt from the Medical Xpress article:
(Medical Xpress)—The classic theory of the brain is one of connections, in which the brain consists of a network of neurons that interact with each other to allow us to think, see, interpret, and understand the world around us. In this model, called distributed representation, an individual neuron by itself has no inherent meaning, but only contributes to a pattern of neuronal activity that has meaning. For example, a certain pattern of many neurons fires when you think "dog" and another pattern for "cat."
"The belief in distributed representation theory is that a concept or object is not represented by a single neuron in the brain but by a pattern of activations over a number of neurons," explains Asim Roy, a professor of information systems at Arizona State University, to Medical Xpress. "Thus there is no single neuron in the brain representing a cat or a dog. Proponents of this theory claim that a cat or a dog is represented by its microfeatures such as legs, ears, body, tail, and so on. However, they think that neurons have absolutely no meaning on a stand-alone basis. Therefore, they go further and claim that these microfeatures are at the subsymbolic level, which means that meaning arises only when you consider the pattern of activations as a whole. Therefore, there are no neurons representing legs, ears, body, tail, etc. The representation is at a much lower level."
Roy is among a number of scientists working in the fields of neuroscience and artificial intelligence (AI) who suspect that the brain may not be as connected as distributed representation suggests. The basis of their alternative model, called localist representation, is that a single neuron can represent a dog, a cat, or any other object or concept. These neurons can be considered symbols since they have meaning on a stand-alone basis. However, as Roy explains, this doesn't necessarily mean only one neuron represents a dog; such "concept cells" are high-level neurons, which fire in response to the firing of an assortment of low-level neurons that represent the legs, ears, body, tail, etc.
"In localist representation, there could be separate neurons for a dog and a cat, and also neurons for legs, ears, body, tail, etc.," he said. "It's very similar to the model in my paper for word recognition, which is an old model from James McClelland <Chair of the Psychology Department at Stanford University> and <the late pioneering neuroscientist> David Rumelhart. You have low-level neurons that detect letters of the alphabet and then high-level neurons for individual words. So letter neurons and word neurons, they both exist."
3 replies, 1580 views
Do brain cells need to be connected to have meaning? (Original post)
Response to Jim__ (Original post)
Sun Dec 9, 2012, 12:18 AM
napoleon_in_rags (3,989 posts)
1. I don't know, let's butcher somebody's still living brain to find out.
Actually, let's not and say we did.
A while ago, I was researching the indigenous people of Siberia, when I found out that they used to cut their great shamans up, and keep their body parts so they could attain the power of them. It was shockingly Ooga booga, and I dismissed this storing of body parts as the way of a very primitive pagan people. Then I remembered the actual Catholic church, how it cuts up and fetishizes the body parts of saints:
Shocking, yes. But at least the scientific community is immune from this Ooga Booga obsession of getting the power from dead people. Then I head about Einstein's brain, which had been illicitly hidden away by scientists who hoped to attain his "power" from the study of his brain.
Ooga booga! All these brain studies fall into the same category as earlier fetishisms of dead body parts: The hope to attain the mysterious powers of the subject through study, but they are all pretty much equivalent to the Siberian shaman corpse mutilations: They resulted in nothing.
Lets instead develop a really rational, mathematical model of inquiry into the nature of our own thought, that develop that through reason and love, rather than through body part obsession. Thought must have a rational, systematic basis regardless of the platform of its deployment (brain). Let's figure out what that is, instead of anatomically obsessing on the functional details.
Response to napoleon_in_rags (Reply #1)
Mon Dec 10, 2012, 02:54 AM
GaYellowDawg (3,270 posts)
What kind of messed up response is this? All of the crap about Siberia and the Catholic Church relics - astoundingly irrelevant to the original post. Then you seem to be claiming that because a few scientists wanted to study a genius's brain after his death to see if it was different, that all neurophysiology studies into the brain - whether they reference Einstein's brain or not - are invalid. Wow.
I couldn't quite figure out the last paragraph. Rational, mathematical model of inquiry into the nature of thought through reason and love? That makes no sense whatsoever. None. And it would be worthless without a biological context within which to place it.
Body part obsession? Anatomically obsessing on the functional details? When you learn how the brain stores/recalls information on a physiological basis, it has a lot of implications into treating traumatic brain injuries. All of the "rational model of inquiry through love" woo bullshit in the world isn't going to help a stroke victim. I really, honestly wonder why in the world people who have an obvious disdain for the scientific process can't just shut up, get out of the way, and let scientists do actual science. Go do your own hobbies and leave scientists alone. Then when you need something like modern medicine, you can actually benefit from it because because they haven't had to defend their studies against woo-woos.
Response to GaYellowDawg (Reply #2)
Sat Dec 15, 2012, 02:46 AM
napoleon_in_rags (3,989 posts)
3. I think I was referring to the "materialization" of the concept of a human.
And I think I might have been drunk when I wrote that, so sorry. But the point I believe I was making is that the trend toward treating human beings like objects has a long and sordid history, from the fetishization of body parts, to slavery, and its continued in diverse forms to this day. Check out this article from Wired:
It’s been fashionable in military circles to talk about cyberspace as a “fifth domain” for warfare, along with land, space, air and sea. But there’s a sixth and arguably more important warfighting domain emerging: the human brain.
This new battlespace is not just about influencing hearts and minds with people seeking information. It’s about involuntarily penetrating, shaping, and coercing the mind in the ultimate realization of Clausewitz’s definition of war: compelling an adversary to submit to one’s will. And the most powerful tool in this war is brain-computer interface (BCI) technologies, which connect the human brain to devices.
We're headed into fantastically dangerous ethical territory with this stuff, but its here. My hope is that we could really start to examine ourselves introspectively, to gain a science of self understanding which regards the self as an information entity, rather than a material one.
And yeah, sorry if that was weird. Booze.