Hello,
Perhaps this is a naiive question...naiive because of the lack of my knowledge of the blood circulation system of the brain.

Anyway, I was wondering if increasing the blood flow to one hemisphere would improve its activity or dominance (at least temporarily).

I came up with this question because, sometimes, when I'm sitting somewhere or listening to a lecture or something of that sort, I become conscious of my posture suddenly and realize that I'm tilting my head to one side. My head is usually closer to one shoulder...and this realization occurs after I've spent a lot of time in that posture. So, I spend a significant amount of time in that tilted posture. I don't really know if this can somehow affect the normal functioning of the brain, but I just was wondering if the blood circulation system could be designed so as to let gravity affect the distribution of the blood flow.

If it does affect hemisphere dominance, then the implication would be colossal! Just tilting your head would make you the person you want to be. If you'd like to think more objectively, just tilt your head to your left!! I have to say, it does sound like a crackpot theory.

So, what do you think?

Regards.

Ok Ok....to put it simply,

Does gravity affect the blood circulation system in the brain? If yes, to what extent?

It's strange that people have been concentrating so much on the issue of blood flow to the brain lately. First one needs a bit of a primer as to blood and the brain.

The brain is not actually bathed in blood. There is another fluid called cerebrospinal fluid (CSF) that takes that role. Cells called ependymal cells, (a modified type of neuron, or "neuroglia") kind of filter larger constituants of the blood into an isotonic solution. This isn't to say flow TO the brain is irrellevant; this is just a bit of background.

These ependymal cells are located at the roof of the lateral ventricles (actually the choroid plexus, but for simplicity....) which are two sacks of fluid, one in the right hemisphere, and one in the left. There are actually blood vessels here that the ependymal cells "filter" from, BUT pressure to both sides is always equal because of a very important structure called, "the circle of willis."

The circle of Willis is exactly that, a circular vessel inferior to the brain. The carotid and vertebrobasilar arteries come together here before other vessels branch off to other areas to become CSF. This guarantees that the local pressures in the brain are consistent.

So to sum it up, blood flow to ependymal cells are the same, and the left and right hemispheres get their CSF from different places (they don't compete for the same fluid.)

So physiologically, your idea doesn't really stand up. Keep in mind though that "physiology" isn't the end all of brain function. It's very well established that neuromuscular conditions are linked to brain activity. i.e. if
I always sit a certain way when doing mathematics, the regions my brain primarily uses for mathematics will light up like a Christmas tree when I sit that way.

If your interested in this secondary aspect, you might want to research NLP, or if your hardcore read, "education of the will" by Jules Payot (in french if possible, lol).

Yes. It is affected because gravity causes increased venous return. Just not in a way that affects one hemisphere more than another. An inversion table will increase overall blood flow to the brain, but not to one side or the other regardless of how you hold your head.

Thank you for that detailed explanation Cassox.

But, I'm sort of disappointed by how much we laymen are consumed by the oversimplified, pseudoscientific myths.

I would be very interested to know more about hemisphere dominance and whether it is plastic or innate. I hear that there are ways through which hemisphere dominance can be shifted temporarily using electrical fields or something similar. Can you lead me to a good source on this topic? Also, it would be nice if you could comment subjectively.

Regards.

I think you're thinking of Transcranial Magnetic Stimulation (TMS), particularly disrupting the left frontotemporal area (which got some press on pseudo savant skills in the participants: art skills, marble counting). You could probably search out some abstracts in Pubmed.

The effect is likely due to disrupting areas which would normally express neural inhibition over other areas of the brain and nervous systems. The frontal lobes are greatly known for their corticocortical inhibitory power. If you inhibit the inhibitors, heh, it definitely changes things.

Left or right brain activity is plastic. It can be changed, not just through TMS but through engaging the mind in activities related to the functions associated with either side. However, the best geniuses use both sides of their brain to the fullest extent possible.

You were given two hemispheres for a reason, use them both to tackle your problems. If you want to make the left hemisphere more active, then engage in left hemisphere activities - if you want to make the right hemisphere more dominant, naturally engage in right hemisphere activities.

For peak mental performance you should engage both sides of your brain. You can use creativity to abstractly go through a problem and at the same time build a logical thought process to reduce the problem into subproblems.

Definitely a crackpot theory. Blood flow is dictated by the blood vessels which creates pressure through constriction and dilation.

P.S. Crack is wack.

And your profile pic is creeeeeepy!

Wouldn't the exact definition of left and/or right hemisphere activity depend on the individual in question.

The majority of the discussion on left and right hemisphere activity in my textbooks discuss their roll in verbal versus mathematical processes (or analytical versus...umm...verbal) So...my question is...what implication does this have on people who can't read and/or write and/or do mathematics...

I mean, there is some work linking the right hemisphere to music and music to mathematics...but...it seems to me that nobody knows for sure.

the end.