 and white matter core.)
SCULPTURE depicts overhead view of brain's cortex (copper) and white matter core.
Image: Sculpture by Margie McDonald, photographed by Frank Ross
In Brief
- White matter, long thought to be passive tissue, actively affects how the brain learns and dysfunctions.
- Although gray matter (composed of neurons) does the brain’s thinking and calculating, white matter (composed of myelin-coated axons) controls the signals that neurons share, coordinating how well brain regions work together.
- A new type of magnetic resonance technology, called diffusion tensor imaging (DTI), has for the first time shown white matter in action, revealing its underappreciated role.
- Myelin is only partially formed at birth and gradually develops in different regions throughout our 20s. The timing of growth and degree of completion can affect learning, self-control (and why teenagers may lack it), and mental illnesses such as schizophrenia, autism and even pathological lying.
Imagine if we could peek through the skull to see what makes one brain smarter than another. Or to discover whether hidden traits might be driving a person’s schizophrenia or dyslexia. A new kind of imaging technique is helping scientists observe such evidence, and it is revealing a surprise: intelligence, and a variety of mental syndromes, may be influenced by tracts within the brain made exclusively of white matter.
Gray matter, the stuff between your ears your teachers chided you about, is where mental computation takes place and memories are stored. This cortex is the “topsoil” of the brain; it is composed of densely packed neuronal cell bodies—the decision-making parts of nerve cells, or neurons. Underneath it, however, is a bedrock of “white matter” that fills nearly half of the human brain—a far larger percentage than found in the brains of other animals. White matter is composed of millions of communications cables, each one containing a long, individual wire, or axon, coated with a white, fatty substance called myelin. Like the trunk lines that connect telephones in different parts of a country, this white cabling connects neurons in one region of the brain with those in other regions.
This article was originally published with the title White Matter Matters.
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1 Comments
Add CommentI'd like to know more about these white-matter connections (if you will, im too lazy to pull out my mag) with respect to people's core, world-view-creating, kind of personal-universe-defining, beliefs..such as ones religion/ethics/morals/philosophies/etc...
Reply | Report Abuse | Link to thisI was thinking about how my long-standing interest in general concepts of (theoretical-type) physics so profoundly shaped the way i percieve all aspects of the world. Sure its just the ley person's (popularish?) understanding, derived from the usual suspects and sources, and I can't recall much serious pre-pubescent exposure, save for dashes of Relativity implications via reading out loud to me by my dad, but it couldn't mean more to me. I really got into the Brian Green/Heisenberg/John Gribbin kinda books around 14-15 years old, and I can recall its just like turning my mind inside out. The first time I saw a description of the famous "Two-Slit Experiment" I must have reread the passage a dozen times. I cannot describe the feeling, other than to say that it felt like I had discovered real, live MAGIC. I'm sure the fact that I didn't grow up at all traditionally religious (and had even recently gone through a very intense, self-scrutinizing, period of just furious rejection off all things organized religion) must have played a part by helping keep my slate blank, so to speak, up to that point.
Now I feel like that foundation in rudamentary physics (as in everything from the Big Bang theory, to the Uncertainty principal, to wave/partical duality, to the Bell/Aspect experiments, to general cosmolog) informs MY overall perspective on reality and (my) existence like the Bible or Koran would for a devote Christian or Muslim, respectively. My querey spawns from the fact that I just don't get quite the same buzz reading new material now, as I didn't back then. People I try to explain the profoundness of of these physical principles and theories to just don't seem to fully get it or something, even if they read the same information, that I once explored, for themselves! Often I wonder whether there is some kind of 'Critical Period' for developing one's world-views, much like there is for learning (a FIRST) language. Of course its just a thought...(if true though, it would make me feel unfathomably lucky to have stumbed upon the path I've followed).
So now that you all understand what I'm talking about, the physics-less adult's analogy in the article would be to the forever-accented 2nd language learner. I'd love to see a study on what part, if any, these white-matter connections in the brain play in a very broad, fundamental, and general learning process (like for that of a religion), verses the much more specific tasks (playing piano, etc.) mentioned specifically in the article. I'm assuming one's overall world-view has, at the least, some part in, and effect on, the perception, and attainment of knowledge via, one's interaction with his or her enviornment.
PERHAPS: do "Born-again" (but FOR THE FIRST TIME, in their case) Christians have weaker beliefs in, and/or a less intuituive grasp of, those principals shared by their life-long, toddler-indoctrinated bretheren?? Does the grandness of the trick affect an old dog's success?
eloheim