Some psychological disorders have a physical basis. In this lesson, we'll look at three types of assessments that examine the link between body and mind: neuroimaging, neuropsychological tests, and psychophysiological tests.
Brain and Behavior
Imagine that you go to a movie theater to see a movie that you've been waiting to see for a long time. Up on the screen, you see the set and actors. You hear the music swelling and watch the light illuminating the scene. All these things work together to make the movie into a cohesive whole. But, there's one thing that you don't see or hear - the director. She works behind the scenes to coordinate and guide every other element of the film. Without a director, the movie would be in chaos, and no one would know what to do.
Your brain is kind of like the director of your body. Your arms move, your heart beats, you feel the swell of love or the pain of rejection, but all of these things are guided and interpreted by your brain. We all know that your brain is responsible for helping you think. And, most of us know that the brain helps your organs work to keep you alive. But, did you know that even your emotions and behaviors are guided by activity in your brain? When it feels like your heart is breaking, it's really your brain sending out signals.
When someone hears voices that aren't there, his brain is working overtime. So, when someone has a psychological issue, often, his or her brain is at the center of that problem. And, it's not just your brain. Because the brain and the body are so intertwined, some psychological disorders actually show up in a person's body as well as in their brain.
Because so many psychological disorders are caused or influenced by a person's physiology, mental health professionals have devised different ways to look at patients' brains and bodies to diagnose and treat mental disorders. Let's look closer at some of the ways that psychologists and doctors assess patients' mental health by examining their physical bodies.
Imagine that you are a psychologist, and Peter comes to you with a problem. About a week ago, with no explanation, he started talking gibberish. He speaks rapidly, and his intonation makes it sound like he's speaking normally, but the words he uses are unrelated. He says sentences like, 'Rabbit yellow for the football in his mouth.'
What's going on with Peter? You're not sure, but you think there might be a problem with the area of his brain that controls language. But, how do you know for sure? Neurological imaging, or neuroimaging, involves taking a picture of a person's brain. There are several types of neuroimaging that mental health professionals use.
Computed tomography, or CT scan for short, is a series of X-rays of the brain taken from different angles. CT scans are great for looking at brain injuries, like when someone hits his head. A CT scan would show if Peter had a brain tumor in his brain, for example. But, what if his CT scan is clear? Does that mean that Peter's brain is fine? You might also want to do a PET scan, which is short for positron emission tomography. In a PET scan, small levels of radiation are injected into the bloodstream. They make their way to the brain and then the scan measures the radiation. In this way, doctors can see levels of activity in different areas of the brain.
Your PET scan of Peter's brain could show if he has a brain disease, like Alzheimer's disease or a brain tumor. Because these problems change the activity levels in certain areas of the brain, they show up on a PET scan even if they don't on a CT scan. But, to do a PET scan on Peter, you would have to inject him with radioactive chemicals. Sure, the chemicals are very low doses of radiation, and they are generally considered to be safe, but it's still radiation. And, CT scans, like other X-rays, use low levels of radiation as well. Wouldn't it be better if there was a way to look at the activity in Peter's brain without radiation?
That's what magnetic resonance imaging, or MRI, does. It uses magnets to form two- and three-dimensional images of the brain, so you can look at Peter's brain and search for anomalies, like brain tumors. An MRI image does essentially the same thing as a CT scan: it shows the basic structures of the brain.
Functional magnetic resonance imaging, usually abbreviated to fMRI, uses magnets to track blood flow in the brain. As a result, you can see the activity in different parts of the brain. Like a PET scan, it allows you to see what areas of Peter's brain are really active and which areas are not. There are many other types of neuroimaging techniques, but these four are the most commonly used in the mental health profession.
Perhaps the neuroimaging techniques don't show anything wrong with Peter's brain. Or, perhaps Peter's health insurance won't pay for expensive neuroimaging without more proof that something is wrong other than the fact that he's talking funny. There are other assessments that you, his psychologist, can do.
Neuropsychological assessments are really any assessment meant to measure a patient's cognitive and motor abilities, while also looking at neurological underpinnings for problems. In other words, a neuropsychological assessment gauges whether there is a psychological problem and then tries to find a physical reason for that problem. Technically, neurological imaging falls under the category of neuropsychological assessments. But, when people talk about neuropsychological assessments, they are usually talking about tests and conversations that are given to check for a patient's abilities.
Remember Peter? He's speaking in a garbled, jumbled up kind of way. As his psychologist, you think he might have aphasia, which is a psychological disorder involving problems with speech. But, there are many types of aphasias. To test whether Peter has aphasia and what type, you give him a test called the Boston Diagnostic Aphasia Examination.
In the Boston Diagnostic Aphasia Examination, you ask Peter many different questions. They start simply, such as asking him how he is and how his day has been. Other questions might involve asking him to point to a part of his body or identify an object from a picture. Through these questions, you can tell whether Peter has aphasia or not and what type of aphasia he has.
The Boston Diagnostic Aphasia Examination is only one of many neuropsychological assessments. Others measure a person's intelligence, memory, problem solving, motor and other skills. The assessment used depends on the patient's problems. For example, since Peter is having trouble with his speech but is moving fine, you wouldn't give him an assessment aimed at his motor skills.
Like neuropsychology, psychophysiology studies the connection between mental issues and the physical body. But, unlike neuropsychology, psychophysiological assessments are not relegated to tests of the brain and related skills. Let's go back to Peter for a second. His speech is messed up. You know that there's something the matter, but you're not sure what. As his psychologist, you might want to examine more than just his brain. In fact, you might want to study his entire body and how it might be affecting his speech.
Psychophysiological assessments look at the way that the body affects and is affected by psychological problems. For example, what if Peter's speech issues are caused or exacerbated by stress? You might want to measure his stress levels and see how stress affects his speech. But, there's not a direct way to measure stress; no one has a stress-o-meter that says, 'Oh, Peter is suffering from this much stress.'
But, there are certain physiological signs of stress that you can measure. For example, you can measure Peter's heart rate or the amount he sweats. Both of these will increase as he becomes more stressed. You might notice that as his stress levels increase, his language problem becomes worse. Other psychophysiological assessments include measuring the levels of certain hormones in the body, the amount a person's eyes dilate and even brain waves. All of these can tell us about the psychophysiology of a patient.
Psychological problems sometimes have physical elements to them, and there are many ways to assess a patient by looking at their physical body. Neuroimaging is a way for psychologists to look at a person's brain and includes technology like CT and PET scans, as well as MRI and fMRI images. In addition, neuropsychological assessments include tests that measure a person's skills in areas like language, intelligence, movement, problem solving and memory. Finally, psychophysiological assessments look at the way the body affects and is affected by psychological disorders. These tests often measure physical elements such as heart rate, hormone levels and brain waves.
After finishing this lesson, you will be able to:
- Identify methods of neurological imaging and what each can show
- Describe neuropsychological assessments and give an example of one
- Recall what psychophysiological assessments measure