Anatomy of the Brain - Cerebral Cortex Function

The cerebral cortex is the thin layer of the brain that covers the outer portion (1.5mm to 5mm) of the cerebrum. It is covered by the meninges and often referred to as gray matter. The cortex is gray because nerves in this area lack the insulation that makes most other parts of the brain appear to be white. The cortex also covers the cerebellum.

The cerebral cortex consists of folded bulges called gyri that create deep furrows or fissures called sulci.

The folds in the brain add to its surface area and therefore increase the amount of gray matter and the quantity of information that can be processed.

The cerebrum is the most highly developed part of the human brain and is responsible for thinking, perceiving, producing and understanding language. Most information processing occurs in the cerebral cortex. The cerebral cortex is divided into four lobesthat each have a specific function. These lobes include the frontal lobes, parietal lobes, temporal lobes, and occipital lobes.

CEREBRAL CORTEX FUNCTION

The cerebral cortex is involved in several functions of the body including:

• Determining Intelligence
• Determining Personality
• Motor Function
• Planning and Organization
• Touch Sensation
• Processing Sensory Information
• Language Processing

The cerebral cortex contains sensory areas and motor areas. Sensory areas receive input from the thalamus and process information related to the senses.

They include the visual cortex of the occipital lobe, auditory cortex of the temporal lobe, gustatory cortex and somatosensory cortex of the parietal lobe. Within the sensory areas are association areas which give meaning to sensations and associate sensations with specific stimuli. Motor areas, including the primary motor cortex and the premotor cortex, regulate voluntary movement.

CEREBRAL CORTEX LOCATION

Directionally, the cerebrum and the cortex that covers it is the uppermost part of the brain. It is superior to other structures such as the pons, cerebellum and medulla oblongata.

CEREBRAL CORTEX DISORDERS

A number of disorders result from damage or death to brain cells of the cerebral cortex. The symptoms experienced depend on the area of the cortex that is damaged. Apraxia is a group of disorders that are characterized by the inability to perform certain motor tasks, although there is no damage to motor or sensory nerve function. Individuals may have difficulty walking, be unable to dress themselves or unable to use common objects appropriately. Apraxia is often observed in those with Alzheimer’s disease, Parkinson's disorders, and frontal lobe disorders. Damage to the cerebral cortex parietal lobe can cause a condition known as agraphia. These individuals have difficulty writing or are unable to write. Damage to the cerebral cortex may also result in ataxia. These types of disorders are characterized by a lack of coordination and balance. Individuals are unable to perform voluntary musclemovements smoothly. Injury to the cerebral cortex has also been linked to depressive disorders, difficulty in decision making, lack of impulse control, memory issues, and attention problems.

MORE INFORMATION

For additional information on the cerebral cortex, see:

• Functional Divisions of the Cerebral Cortex
• Cerebral Lobes

DIVISIONS OF THE BRAIN

• Forebrain - encompasses the cerebral cortex and brain lobes.
• Midbrain - connects the forebrain to the hindbrain.
• Hindbrain - regulates autonomic functions and coordinates movement.

This article originally appeared on thoughtco.com and was written by Regina Bailey

A New Way to Trick the Brain and Beat Jet Lag

For all its complexity, the human brain is not hard to deceive. Here are four studies where scientists have learned more about duping it.

The human brain is a remarkable, stunningly complex organ. And yet, scientists are discovering something about it that the likes of Harry Houdini and other great magicians have known for a long time—the brain can be surprisingly easy to trick.

That’s because in order to be so efficient, it has evolved to create shortcuts in response to outside stimuli, such as light or sound. But those shortcuts and the consistency with which the brain follows them can also make it vulnerable to deception.  

Take, for example, recent research by Stanford scientists exploring a new way to fight jet lag. For a while, researchers have known that exposure to light before taking a trip can help your body adjust to the changes in your sleep cycles that come with traveling across time zones. The most common preventive treatment involves sitting in front of bright lights for hours at a time during the day.

But the Stanford team, led by Jamie Zeitzer, an assistant professor of psychiatry and behavioral sciences, tried a different approach.  First, it looked at light exposure while someone was actually sleeping, and it found that the body’s circadian rhythms, which control sleep cycles, are more sensitive to light at night—even when a person’s eyes are closed.

Then, the researchers wondered if the kind of light passing through the eyelids makes a difference. They recruited 39 volunteers and had them get on a regular sleep cycle for two weeks—going to bed and waking up at the same times every day. Then they brought them into a sleep lab.

They divided the participants into two groups. Once they had fallen asleep, the people in one group were given the conventional treatment—exposure to continuous light for an hour. But the others were treated with a different kind of light—quick flashes 10 seconds apart, like a strobe.

What they found the next night is that the people exposed to the flashing light felt sleepy about two hours later than they had the first evening. For those given the continuous light treatment, sleepiness was delayed by only 36 minutes.

Biological hacking

Zeitzer, who refers to this therapy as “biological hacking,” says the light exposure works better at night because it fools the brain, as you fall asleep, into thinking the day is longer than it actually is. And that resets the body clock.

But why would a flashing light do this more effectively than a constant one?

According to Zeitzer, it has to do with the cells at the back of the eye, which send messages to the part of the brain that sets circadian rhythms. Those cells, he says, use the times of darkness between flashes to recover or recalibrate, and that apparently helps them be more responsive to the light when it reoccurs.

So far, he noted, most of those tested haven’t had a problem sleeping through the flashing lights. In the real world, Zeitzer sees the therapy working like this: Say, you’re flying across the U.S. from the West Coast to the East Coast. If you usually wake up at 8 a.m., you’d set a device to start the light flashes at 5 a.m. By the time you land, he says, your body clock should already be adjusting to East Coast time.

More tricks

Here are three other recent studies in which researchers have found how the brain can be deceived.

Don’t watch what you eat: If you can’t see what you’re eating, you’re less likely to eat as much. That’s the conclusion of scientists at the University of Konstanz in Germany after asking 90 students to eat three different flavors of ice cream.

Forty were told to evaluate the taste and texture of the ice cream, and then estimate how much they had eaten and whether they would buy that ice cream. Pretty straightforward. But the other 50 were thrown a bit of a curve. They were asked to do the same taste test blindfolded.

The results, published in the journal Food Quality and Preference, suggested that those who couldn’t see what they were eating estimated they had eaten almost twice as much as they actually did. They also ate less than the people without the blindfolds. Plus, they were less likely to say they would buy the ice cream.

Based on their findings, the researchers said that those who want to lose weight should try to eat with their eyes closed more often.

Beware of overthinking: A study at the University of Southern California found that if you want to develop a new habit, you should avoid thinking too much about it.

The researchers asked a group of people to watch a video that shows how to make sushi. And they determined that when people were able to watch the video over and over without any other specific instructions, they learned the sushi-making process better than those who were told to try to remember what came next.

The reason, according to researcher Jennifer Labrecque, is that habits are encoded in the brain by what’s known as the procedural memory system, which doesn’t involve much deliberative thinking. That’s what involved when you get back on a bike. But when you plan and concentrate on learning, you engage the declarative memory system, which remembers facts and personal experiences. 

When you try to use both systems at once, they can interfere with your learning, she said. You’re better off not thinking too hard when you’re trying to learn something new.

Is someone there?: Do you ever have that feeling where you can sense the presence of another person in the room with you when no one else is around? Well, scientists at the Swiss Federal Institute of Technology say it’s likely a case of your brain perceiving something that’s not there.

That’s based, in part, on research done with a group of people who were blindfolded, given ear plugs and had their fingers connected to a device. The subjects were told to move the device, and when they did, a robotic arm poked them in the back. Because the poke was synchronized with their movements, the subjects’ brains recognized it as something they had done to themselves.  

But when the researchers caused a slight delay between when the people moved the device and when they were poked, the study participants had a different reaction. They swore that not only was someone else touching them, but that they could actually feel another person’s presence. A few, in fact, found the experience so unsettling that they chose not to finish the experiment.

That strange sensation, according to the scientists, was caused by an altered perception within their brains, one that made them feel their own bodies had been replaced by someone else’s presence.

Read more: http://www.smithsonianmag.com/innovation/new-way-trick-brain-and-beat-jet-lag-180958271/#JbjX7sR1tC24DRdU.99
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