Corpus Callosum, Epilepsy & Split-Brain Experiments

This page discusses the corpus collosum and it's relationship to epileptic seizures, the surgery to cut the corpus callosum for epilepsy, resulting in the split brain patients experiment, and research & studies with the split brain operation.

The corpus collosum (also spelled callosum) are the nerves that connect the right and left sides of the brain.

The corpus collosum makes the brain integrate structures and process them together.

Autistics are extremely structured; they are very much in the right side of the brain.

In an epileptic person, seizures are caused by all the electricity going back and forth across the corpus collosum between the different sides of the brain.

If the person has petit mal, she would be likely to pause briefly as the epilepsy takes over, and then continue what she is doing a moment later.

If she has a grand mal, during an epileptic seizure she would likely be writhing on the floor and flailing her arms uncontrollably.

Many epileptics have extreme attacks that leave them writhing on the floor, flailing their arms, with saliva coming out of their mouths.

Their condition restricts them from many activities, such as driving, and also restricts the types of jobs that they can have.

For example, they normally cannot be an actor or singer or player in any live performance, or drive any vehicle or aircraft.

Understandably, people that suffer from epileptic seizures would wish to cure the problem.

A method used is to cut the nerves in the corpus callosum, effectively separating the two sides of the brain.

The brain is split, the nerves cut through to stop epilepsy.

Since the nerves were cut, the electricity can't go back and forth anymore.

This stops epileptic seizures but has other affects on the brain and the person as a whole.

It is possible for a split-brain student to study for an English exam and a geometry exam at the same time by using a Z lens.

It only works if the corpus collosum was cut first, which, as explained above, is used to cure epilepsy.

A Z lens is a contact lens that is opaque on one side and clear on the other.

The person should wear a Z lens in each eye.

The inside of the lens on each eye needs to be covered, by the nose.

In this way, each eye registers only the half that is visible on its side.

We are effectively blocking half of eyesight from each eye.

Now, since the patient has a split brain, the patient could study two different things at the same time, when the Z lens blocks half the vision in each eye.

With the Z lens, the person can read two books at the same time, one with each eye.

It's a nice trick, but can't always be used at the same time.

Although this sounds good, there are a lot of negative effects to having the brain split and not communicating between the two sides.

The decision to perform commissurotomies on epileptic patients turned out to be a good one; the decision to perform pre- frontal lobotomies on mental health patients turned out to be a bad one.

Up to a point, it was luck.

The scientists were going in blindly, testing out different theories.

Lobotomies were not very sophisticated and did not have much prior testing before being made public.

The researchers were lucky with the positive results with cutting the nerves in the corpus collosum in epileptic patients.

An fMRI is a functional MRI.

A regular MRI just takes one picture of the brain, one time.

A functional MRI takes a picture for 3 seconds, every 30 seconds, so you see the changes as the person is doing something.

For example, as they are reading and lying in a tube, the fMRI is taking pictures of the brain and seeing where reading and comprehension occur, by looking at what parts of the brain are warm.

If the brain was one big un- separated mass, confusion would happen.

If the brain was two separate masses, separated without the corpus collosum, meaning there would be no communication between the different sides which have different functions, then that would also be a problem.

They have to be separated so they don't interfere with each other, but they need to be able to communicate with one another through the corpus collosum to manage the body's functions appropriately.

For example, animals are not as well developed, at some point they tried to get down from the tree and developed their corpus collosum to help them walk on the ground and live there.

They don't have the dexterity that we have, they can't walk normally, show creativity, sew, knit, play a tune on a keyboard and many other activities that humans can do.

Animals function well in trees but not on the ground. This is partially due to the fact that they don't have a well developed corpus collosum.

Wiki on Corpus Callosum