I have heard that we use only 10% of the brain?

Question

does the medical proffession have any idea what happens in the other 90%?

Answer 1

It would seem that the brain has tremendous built in redundancy where the activity of neurons in establishing new synapses can compensate for a lesion or impairment. There are controversial medical records of subjects suffering from extreme hydrocephalus, where 95% of the skull space is occupied by cerebrospinal fluid, leaving only a 1mm thin cortical layer against the skull. Yet some of these subjects seem to present all the normal functions of mental aptitude. So it looks like due to this built in plasticity of the brain we only actually NEED about 10% functioning capability- the rest could be 'spare parts'!

Answer 2

Evidence of human behaviour to the contrary, your assertion is untrue. We use far more than 10% of our brains.

This figure was arrived at by some scientists who trained mice to run a maze. They then removed bits of their brain until they could no longer perform the task and that's how they came up with this number.

Needless to say, we're not mice (well, most of us, anyway) and things work a little differently in our heads than that of a minor rodent. And although a large portion of our brain could be removed and we could still function, we would not have 100% functionality. In other words, we might be able to take the train to work and sweep the floors, but we might have some more trouble reading the newspaper or remembering to pick up the kids at school.

Short answer to your question - it gets used just as much as the 10% your using right now.

Answer 3

Actually, I think it is closer to 6%. There is activity all over the brain, but this percentage of activity applies to the firing of neurons, and looking at it relative to the availability of neurons, we barely use our brain at all. The rest of the neurons are not used to control our "automatic" functions, though.
Use of far more than 6% of a brain has been recorded, but this is considered overuse and it almost always ends in defeciencies in some area of brain function. Examples of this are savants, who can perform mind-boggling feats of calculation, yet cannot take part in a simple conversation due to their lack of social skills.

Answer 4

This is a myth started long ago. It you use positron emission tomography (PET scan) to visualize the brain while functioning it seems that we use most of it. And we use most of it at some level all of the time.

You can ilicit hot spots by asking specific questions or asking for certain motor functions, but that doesn't mean most of the rest of the brain is not functioning. It is just working at a lower level.

Answer 5

Some of us use part of that extra percentage to wonder if the premise is true. It isn't. You use a lot of your brain, depending on what you are doing at the time. The old 10% tale is well-established but without foundation.

Answer 6

No, that is total hogwash that was invented by a motivational speaker. If you want to know how much of the brain is used look up patients who have had brain damage. It is all in use any even very minor damage has effects that are sometimes severe!
http://faculty.washington.edu/chudler/tenper.html

Answer 7

Our cognitive thinking may use 10% but the brain does a lot of maintenance of in the body and controls the nervous system. If you had to think every time you breathed, you'd be dead.

Answer 8

That's rubbish. We use all our brain. If we only used 10%, surely 90% of brain injuries would have no effect.

EEGs and other scans detect activity in all portions of the brain.

Correction - some people on Y!A use very little of their brain.

Answer 9

You don't want the whole brain firing at once. That's a seizure. You use ALL of your brain, just not all at the same time.

The evidence for this is that injury to the human brain leads to deficits. You can't knock out chunks of brain and carry on as usual. (At least, not most of us)

Answer 10

We use all of our brain but only about 10% of its power