What Is The Cerebral Cortex
What is the cerebral cortex? The cerebral cortex is the most important part of our brain (at least in the field of psychology) because it is what makes us human. The cerebral cortex (sometimes referred to as called “gray matter”), is actually densely packed neurons. We actually are born with more neurons in our cerebral cortex than we have now, but they are young and inexperienced. As you get older the neurons learn to work together forming what we call neural networks in the cerebral cortex. Let’s go back to when you were a kid and your parents taught you how to wipe your own butt. The first time you wiped it was awkward, you probably wiped poo poo everywhere and had to concentrate really hard. The neurons in your cerebral cortex were firing in the pattern of butt wiping for the first time. Every time you wiped your butt afterward, the neurons practice. Pretty soon those bunch of neurons that fire whenever you have to wipe your butt form a butt wiping team called a neural network. Today you probably do not even have to think when you wipe your tushy because your neural network has formed such a cohesive team- congratulations!!!
Now our cerebral cortex is pretty big and full of wrinkles– these wrinkles are call fissures. If you took out your cerebral cortex and ironed out all of the wrinkles it would be as big as a large pizza from Pizzeria Uno (but probably would not taste as good).
Now the cerebral cortex is divided into two hemispheres– the left and right hemispheres. For the most part the hemispheres exhibit what we call Contralateral control: which means the left hemisphere controls the right side of out body and the right hemisphere controls the left side. In general, right handed people (those with a stronger LEFT hemisphere) seem to be better at logical and sequential tasks. Left handed people (those with a stronger RIGHT hemisphere) are better at spatial and creative tasks.
Between the two hemispheres is a band of nerve fibers called the corpus callosum. The job of the corpus callosum is to help the two hemispheres communicate with each other. In some cases of people with severe epilepsy, the corpus callosum is surgically removed and the seizure activity decreases. However, these people lose the ability of there hemispheres to communicate to each other- they are called split brain patients. They actually have two separate brains inside their head, and one brain has no idea what the other is doing. For example, for most people the ability to see comes from the left hemisphere (which controls the right field of vision). So if a split brain patient sees an elephant in their left visual field they will not be able to say what they see, but they can write it with their right hand (but not left hand)- get it? Through the process of plasticity (which you should already know) most split brain patients will compensate and find ways for the hemispheres to communicate.
Areas of the Cerebral Cortex
We are going to talk about alot of places in the cerebral cortex-but there are also even more places that we will not talk about. Let’s call these places association areas– or areas that are involved in thought, memory, judgment humor, etc….- basically all areas not involved in sensory information or movement are association areas.
The Lobes of the Cerebral Cortex
Our cerebral cortex is divided up into four lobes (areas). However, to be more specific, we really have eight lobes because each lobe has a right and left side- remember the cerebral cortex is contralateralized!!!
Frontal Lobes
The frontal lobes are located at the top part of our brain behind our eyes. The frontal lobe is where most of our personality hangs out. It is involved in the ability to control our emotions and abstract thought. There are two specific areas in the frontal lobe that you should know for the AP Exam:
| Motor Cortex Located in the back of the frontal lobe this thin strip of tissue sends signals (motor neurons) to tell our body to move. The things we move more (fingers) have more space devoted on the motor cortex, than parts of us we do not move much (pinky toes). The top of the motor cortex controls the bottom of our body and the bottom of the cortex controls the top of our body. If that is too confusing, just know that every time you voluntarily move your body, you are using the motor cortex in the frontal lobe. | |
| Broca’s AreaLocated in the left frontal lobe (at least for most people- in some left handed people, Broca’s area is on the right side), this areas controls the muscles in our mouth involved in speech. Speaking is a complicated task and we have a whole area devoted just to talking. If you damage Broca’s area (called Broca’s Aphasia) you will be unable to talk. |  |
Parietal Lobes
The parietal lobes are located in back of the frontal lobes on the top of our head. Most of the parietal lobes are made up of association areas. There is only one structure you should know:
| Sensory CortexLocated in the front of the parietal lobe (directly behind the sensory cortex in the frontal lobe), this structure is responsible for us feeling touch sensations from our body. Every time you feel a type of touch sensations (both pleasurable and pain) the information is sent up by sensory neurons to the thalamus and sent to the sensory cortex so we can feel it. It is set up the same way the motor cortex is (see picture to right) in that the bottom of the cortex is responsible for the top of our body and the top of the cortex responsible for the bottom of our body. |
Occipital Lobes
Located in the very back of our brain, the occipital lobes are responsible for our eyesight. They contain the primary visual cortex which helps us interpret the information sent to us by our eyes (more specifically the retinas located in the back of our eyes- but we will get into that later on). Just to make your lives a little more confusing- do you remember that our cerebral cortex is contralateralized- well so are our eyes- kind of. You see, the right half of each of our retinas sends info to the left side of the occipital lobe and the left side of each retina sends info to our right occipital lobe. Follow that- yeah right!!! I will explain it in class.
Temporal Lobes
Located just above our ears on both sides of our head, the temporal lobes control our hearing and contain the auditory cortex. What makes the temporal lobes so unique is that are NOT lateralized. The left temporal lobe is involved in BOTH the hearing from the right and left ear. There is one critical structure you should know that is in the temporal lobe:
| Wernicke’s AreaWernicke’s area is located in our left temporal lobe and is responsible for interpreting BOTH written and spoken speech. You use Wernicke’s area both the read and to listen. If you damage Wernicke’s Area (Wernicke’s Aphasia) you would be unable to understand what you are reading or hearing. |
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How Does Memory Work?
Memory connects to the methods that are used to receive, store, retain, and later retrieve information. There are three main processes involved in memory: encoding, storage, and retrieval.
Human memory includes the ability to both process and recover information we have received or experienced. As we all know, though, this is not an impeccable process. Sometimes we forget or misremember information. Sometimes ideas are not properly encoded in memory in the first place. Memory difficulties can vary from minor annoyances like forgetting where you dropped your car keys to major diseases that affect the essence of life and the capacity to operate.
How Are Memories Formed?
In order to form new recollections, information must be changed into a suitable form, which happens through the method known as encoding. Once the information has been successfully encoded, it must be saved in memory for later usage. Much of this stored memory rests outside of our awareness most of the time, except when we actually require to use it. The retrieval process enables us to bring stored memories into mindful awareness.
How Long Do Memories Last?
Some memories are very fleeting, just seconds long, and enable us to take in sensory information regarding the world around us.
Short-term memories are a touch longer and last about 20 to 30 seconds. These memories regularly consist of the information we are currently concentrating on and thinking about.
Finally, some recollections are able to endure much longer and last days, weeks, months, or even decades. Most of these long-term memories extend outside of our direct awareness, but we can draw them into consciousness when they are wanted.
Using Memory
To use the information that has been drilled into memory, it first has to be recovered. There are many factors that can impact how memories are reclaimed such as the kind of information being used and the retrieval signals that are present.
Of course, this method is not always accurate. Have you ever felt you had the key to a question right at the tip of your tongue, but you couldn’t really remember it? This is an example of a bewildering memory retrieval difficulty known lethologica, or the tip-of-the-tongue phenomenon.
Discover the basics of thought retrieval as well as potential problems with this process in this overview of how memories are retrieved.
Memory Model
While various different models of memory have been introduced, the stage model of memory is frequently used to explain the basic composition and function of memory. Initially recommended in 1968 by Atkinson and Shiffrin, this hypothesis outlines three separate stages of memory: sensory memory, short-term memory, and long-term memory.
Sensory Memory
Sensory memory is the initial platform of memory. During this stage, sensory information from the atmosphere is stored for a brief period of time, ordinarily for no longer than a half-second for visual knowledge and 3 or 4 seconds for auditory information. We visit only particular phases of this sensory memory, providing some of this information to move into the next stage of short-term memory.
Short-Term Memory
Short-term memory is additionally known as active memory, which is the information we are currently aware of or thinking about. In psychology, this memory would be attributed to the conscious mind. Paying attentiveness to sensory memories causes the information in short-term memory. Most of the data stored in active memory will be held for approximately 20 to 30 seconds. While many of our short-term memories are swiftly forgotten, tending to this information allows it to proceed to the next stage – long-term memory.
Long-Term Memory
Long-term memory refers to the ongoing storage of information. In psychology, long-term memory would be called preconscious and unconscious. This information is mostly outside of our awareness but can be called in working memory to be used as needed. Some of this information is reasonably easy to recall, while other memories are greatly more difficult to access.
Memory Organization
The ability to locate and retrieve information from long-term memory enables us to actually apply these memories to make decisions, interact with others, and solve difficulties. But just how is information arranged in memory? The specific way information is arranged in long-term memory is not well known, but researchers do know that these memories are organized in groups.
Clustering is utilized to organize related information into collections. Information that is categorized converts to easier to remember and recall info. One way of thinking about memory structure is known as the semantic network model. This model proposes that certain triggers stimulate associated memories. A memory of a particular place might stimulate memories about related things that have happened in that location. For example, thinking about a particular university building might trigger recollections of attending classes, studying, and socializing with peers.
Failing Memory
Forgetting is a surprisingly frequent event. Just consider how regularly you forget someone’s name or overlooked an important meeting. Forgetting can happen for a whole number of reasons including a failure to recover the information from long-term memory.
Research has shown that one of the significant factors that influence memory failure is time. Information is often quickly forgotten, especially if people do not actively review and rehearse it.
Forgetting
Why do we forget information we have received in the past? There are four basic answers for why forgetting occurs: retrieval failure, interference, failure to file and motivated forgetting.
Sometimes information is utterly lost from memory and in other cases, it was never deposited correctly in the first place. Sometimes memories collide with one another, making it difficult to retrieve certain information. In still other cases, people actively try to disremember things that they simply don’t want to remember.
Boosting Memory
No matter how exceptional your memory is, there are presumably a few things you can do to get it even better. Fortunately, cognitive psychologists have identified a number of techniques that can help advance memory.
Final Thoughts on Memory
Human memory is a multifaceted process that researchers are still trying to properly understand. Our memories shape us into who we are, yet the process is not flawless. While we are capable of remembering an extraordinary amount of information, we are also susceptible to misunderstandings and errors.