Learn how the brain functions and how injuries can differ depending on which part or parts of the brain were damaged.
[♪music♪] [Module 2: Basic Brain] What I'd like to talk to you about now is about the basic brain and how it functions. The brain has three major parts: the brainstem, the cerebellum, and the cerebrum. The brainstem takes care of many basic bodily functions of which many of them you are unaware of, such as your cardiac function; respiration. It also controls arousal, whether you are awake or asleep, and movement and touch and sensation in the body. The cerebellum controls the balance of the body and coordination of body movement, so when you have damage to this part of the brain, one of the difficulties that you will have is being able to walk properly or maintain your balance. The cerebrum is the last part of the brain to have evolved, and it is the largest part of the brain. It has four lobes: the frontal lobe, the temporal lobe, the occipital lobe, and the parietal lobe. The frontal lobe is located under the forehead, and it is the largest section of the brain. It is also the last section to have evolved in humans, and it is involved in what we call executive functioning. It's really the part of the brain that is involved in decision making and reasoning, and it takes all the rest of the information from the brain, processes it, and helps you make decisions. So when this lobe is injured, there are many, many different types of problems that can occur and many of these problems are not always readily noticeable to the individual. One of the problems is attention. When individuals have injuries to the frontal lobe, they really oftentimes have problems being able to pay attention to things. And so, without being able to pay attention to things, frequently, children cannot learn or people cannot stay focused on what they're doing. People also have problems with planning and organization. Now, this is a very interesting issue, because many times people cannot sequence activities or plan to do activities--even simple activities that you and I take for granted every single day, such as making a simple meal or dressing. Another problem with frontal lobe injuries is initiation. The frontal lobes contain the start and stop button of the brain. Essentially, what this means is that when you want to start an activity, it is the frontal lobe that signals you to start, and it's also the frontal lobe that tells you when to stop. This can be a very subtle problem, but it can manifest itself in very unusual ways. For example, somebody can describe to you exactly how to perform a very simple task--let's say making a sandwich. They can give you all the steps and they can tell you all the ingredients that they will need to do that. You can put all of the ingredients out in front of the individual, and even though they've told you exactly how they would do it and they've given you the correct sequence of steps, they will sit there and not actually start making the sandwich until you give them a cue, "Start making a sandwich." And what they will do at that point is maybe pick up the piece of bread, and they will then need to be cued again, "You need to put mayonnaise on it." They will do that, and they will stop. In each phase of the activity, the individual needs to be cued. This is because their initiation center has been damaged. Sometimes, it is a problem of not being able to control a behavior or they work impulsively so that they cannot stop doing something. So very often, you have seen children who continue doing an activity over and over and over again and you have to tell them to stop. Well, when this happens in an adult after a brain injury, this can be very troublesome. Another problem that people have with frontal lobe injuries is with problem solving and flexibility. What this means is that typically people are unable to even solve some of the simplest problems, and if they find a solution, they will frequently keep repeating this solution even though it doesn't work. So this problem leads to some very significant inflexibility and causes difficulty because people keep repeating the same behavior over and over and over again without it giving them the result that they want. Another problem is judgment. We have all known people who have poor judgment. However, with people with brain injuries-- especially in the frontal lobe area-- their judgment tends to be very, very poor, and leads to very bad decisions that frequently can lead to additional injuries. There are also many personality changes that can occur with a frontal lobe injury. Individuals can exhibit very inappropriate behavior and oftentimes, this can be inappropriate sexual behavior or inappropriate language, and usually at the wrong time. So very often, this can be very embarrassing for families and it can also mean that people lose their temper and get out of control, which can cause problems with law enforcement, or other types of difficulties, like getting thrown out of school. And so, very often, individuals who have these types of problems can also wind up being incarcerated. Other difficulties can be related to speech, muscle weakness, and some paralysis. The temporal lobe is the part of the brain that is involved primary with hearing and also understanding speech. So although an individual may actually be able to hear and there is nothing wrong with their ear or their hearing mechanism, the brain is unable to process the information. This can also lead to somebody being unable to understand what other people are telling them. Another problem is with memory. Now, when we speak about memory problems in people with brain injuries, it is generally not related to memories that they have for events a long time ago. Long-term memory tends to stay intact. The type of memory problems that people have with brain injuries really has to do with short term memory. So you can ask someone what they had for breakfast or what they had for lunch, and they will not be able to remember it, but they will probably be able to remember the name of their first grade school teacher. This type of short term memory problem is very, very problematic for people. It means that they forget what people tell them on a day-to-day basis and results in them being unable to function in a job or in school. The other area that the temporal lobe is involved in is music and sound comprehension. The occipital lobe is located near the back of the brain, and the occipital lobe really is involved in the interpretation of visual information. So essentially, the information that comes into the brain through the occipital lobe helps you understand and identify what you are seeing. The parietal lobe is located at the top of the brain. It is involved in perception of touch and body orientation, so where your body is in space. It also helps you recognize faces and it helps you with the awareness of spatial relationships. It's also involved in arithmetic calculations, so sometimes many of us feel like we've got problems with our parietal lobe because we're not very good in arithmetic. [♪music♪] [End of Module 2]
Posted on BrainLine April 8, 2011.
Produced by Texas Department of State Health Services and the Texas Traumatic Brain Injury Advisory Council.