I didn't watch the movie. I'd heard that it wasn't that good, so I didn't go.
I don't know if the Wikipedia article addresses the point the way people understand it. I think that people are considering using their whole brain in ways that are similar to when a part of the brain is actively functioning in a concentrated effort.
Anyway, It reminded me of Isaac Asimov's
Pebble in the Sky. A quote from the book is below. Enjoy:
Shekt’s eyes twinkled. “Well, then, to stick to descriptive matter only, it is simply a device intended to increase the learning capacity of a human being.”
“Of a human being? Really! And does it work?”
“I wish we knew. Much more work is necessary. I’ll give you the essentials, Procurator, and you can judge for yourself. The nervous system in man--and in animals--is composed of neuroprotein material. Such material consists of huge molecules in very precarious electrical balance. The slightest stimulus will upset one, which will right itself by upsetting the next, which will repeat the process, until the brain is reached. The brain itself is an immense grouping of similar molecules which are connected among themselves in all possible ways. Since there are something like ten to the twentieth power--that is, a one with twenty zeros after it--such neuroproteins in the brain, the number of possible combinations are of the order of factorial ten to the twentieth power. This is a number so large that if all the electrons and protons in the universe were made universes themselves, and all the electrons and protons in all of these new universes again made universes, then all the electrons and protons in all the universes so created would still be nothing in comparison....Do you follow me?”
“Not a word, thank the Stars. If I even attempted to, I should bark like a dog for sheer pain of the intellect.”
“Hmp. Well, in any case, what we call nerve impulses are merely the progressive electronic unbalance that proceeds along the nerves to the brain and then from the brain back along the nerves. Do you get that?”
“Yes.”
“Well, blessings on you for a genius, then. As long as this impulse continues along a nerve cell, it proceeds at a rapid rate, since the neuroproteins are practically in contact. However, nerve cells are limited in extent, and between each nerve cell and the next is a very thin partition of non-nervous tissue. In other words, two adjoining nerve cells do not actually connect with each other.”
“Ah,” said Ennius, “and the nervous impulse must jump the barrier.”
“Exactly! The partition drops the strength of the impulse and slows the speed of its transmission according to the square of the width thereof. This holds for the brain as well. But imagine, now, if some means could be found to lower the dialectric constant of this partition between the cells.”
“The what constant?”
“The insulating strength of the partition. That’s all I mean. If that were decreased, the impulse would jump the gap more easily. You would think faster and learn faster.”