Another brain question!

[Freeman]

Everyone uses either the right or left side of the brain prodominantly, right? Is it possible to use both sides just as equally?

[LucidDreamer]

It's really not as simple as right brain or left brain dominancy. Certain mental functions are usually found on one side of the brain or another but some can actually be found on either side of the brain (even though they usually have a preference). A lot of the functions that people call right-hemisphere functions or left-hemisphere functions actually require sections of the brain from both hemispheres to work. Even if you took a very simplistic viewpoint of left-brain equals analytical and right brain-brain equals creativity you could always point out people like Leonardo Da Vinchi who obviously had both. And not everyone is even restricted to right or left hand dominance; some are ambidextrous. The whole thing about right-brain people being one way and left brain people being another is an exaggeration.

[Glider]

LucidDreamer is right. Some functions are topographically lateralized anyway. However, those functions that are not related to specific areas in one or other hemisphere exist on a continuum of lateralization; from strongly lateralized to generalized (i.e. employing both hemishperes equally). On average, females tend to be more generalized and males tend to be more lateralized.

 

A good place to look for lateralisation would be split brain studies. This is where people with severe and life-threatening epilepsy have had the two hemispheres separated through surgical incision of the corpus callosum. Studies on these people have shown some startling insights into lateralised function and the relative contribution of each hemisphere to daily life.

[brooke7holley]

You use your left rain to control the right side of body and the right brrain to control the left side.

[PhDwannabe]

Much of what you hear about people being--as if it were a sort of personality characteristic--"right" or "left-brained" is essentially pop neuroscience that isn't grounded in reality. Sure, people can be characterologically more logical, more verbal, more creative, etc. than others. But that doesn't necessarily correspond to some sort of cartoonish view of increased strength, size, or activity on one side of the brain. I'll expand a little on Glider's good comments about lateralization:

 

Even the what we normally talk about as lateralized functions are really representations of most of the population. For instance, language, which everybody seems to know is on the left side of the brain, actually ends up on the right for about one in twenty right-handers, and about one in five left-handers. Another fifth of lefties, and a very very small number of righties, actually show bilaterally distributed language functions. There are those who like to emphasize how separate the functions of the two hemispheres are; this is part of a tradition in neuroscience which emphasizes localization of function (in opposition to a different line of thinking which tends to emphasize the holistic function of the brain.) Nonetheless, most of what you are able to accomplish behaviorally involves use of, communication between, afferent inputs into, and efferent outputs from, both hemispheres of the brain. (That isn't to say that it isn't plastic enough--particularly in kids--for one half to take over a lot of stuff if the other half gets cut out.)

 

We've got plenty of variation between members of the species, which is unsurprising for something as evolutionarily recent as the neocortex. While our current anatomical/functional maps of the brain are a bit better than their phrenological predecessors, they're still only general guides. This is why people often undergo wakeful brain surgery before they get anything major cut out of it--the surgeon has to get in there, press on something, and ask the patient to add and subtract, name animals, sing, etc. Obviously, they don't want to cut out anything major. Since every brain is different, they need to establish the map for that individual, rather than rely on a general one that doesn't apply well enough to any individual brain.

 

 

 

 

Edit: holy hell, I just saw the OP was from 2004. brooke7holley, what on earth are you doing dragging 7-year-old threads out of their graves?

Edited May 22, 2011 by PhDwannabe

[DrmDoc]

Much of what you hear about people being--as if it were a sort of personality characteristic--"right" or "left-brained" is essentially pop neuroscience that isn't grounded in reality. Sure, people can be characterologically more logical, more verbal, more creative, etc. than others. But that doesn't necessarily correspond to some sort of cartoonish view of increased strength, size, or activity on one side of the brain. I'll expand a little on Glider's good comments about lateralization:

 

Even the what we normally talk about as lateralized functions are really representations of most of the population. For instance, language, which everybody seems to know is on the left side of the brain, actually ends up on the right for about one in twenty right-handers, and about one in five left-handers. Another fifth of lefties, and a very very small number of righties, actually show bilaterally distributed language functions. There are those who like to emphasize how separate the functions of the two hemispheres are; this is part of a tradition in neuroscience which emphasizes localization of function (in opposition to a different line of thinking which tends to emphasize the holistic function of the brain.) Nonetheless, most of what you are able to accomplish behaviorally involves use of, communication between, afferent inputs into, and efferent outputs from, both hemispheres of the brain. (That isn't to say that it isn't plastic enough--particularly in kids--for one half to take over a lot of stuff if the other half gets cut out.)

 

We've got plenty of variation between members of the species, which is unsurprising for something as evolutionarily recent as the neocortex. While our current anatomical/functional maps of the brain are a bit better than their phrenological predecessors, they're still only general guides. This is why people often undergo wakeful brain surgery before they get anything major cut out of it--the surgeon has to get in there, press on something, and ask the patient to add and subtract, name animals, sing, etc. Obviously, they don't want to cut out anything major. Since every brain is different, they need to establish the map for that individual, rather than rely on a general one that doesn't apply well enough to any individual brain.

 

 

Edit: holy hell, I just saw the OP was from 2004. brooke7holley, what on earth are you doing dragging 7-year-old threads out of their graves?

Although you did not quote your source or provide a citation, that Wikipedia article on Lateralization of brain function--from which you obviously supplemented your general knowledge on this topic--is a good start, I would recommend that readers here view the article for themselves then move on to more substantial sources of neuroscience and neuropsychology such as:

 

Kolb B., Whishaw IQ., Fundamentals of Human Neuropsychology, New York: Worth Publishers.

Nolte,J., The Human Brain: An Introduction to Its Functional Anatomy, St. Louis: Mosby Publishers.

 

These published works explore the current research and research history in exceptional detail. Happy hunting!

Edited May 22, 2011 by DrmDoc