The brain dictates much of how we perceive and react to the world around us. When the brain works differently than normal, it can lead to mental illnesses like schizophrenia. In this lesson, we’ll examine the parts and functions of the brain that can lead to schizophrenia.
Schizophrenia and the Brain
Why do people act the way they do? Why do some people hear and see things that aren’t there and others can’t hear or see things at all?Schizophrenia is a psychotic disorder that affects about 1% of people.
People with schizophrenia suffer from hallucinations and delusions, among other things. Hallucinations involve hearing or seeing things that aren’t real, such as hearing voices in your head. Delusions are false beliefs that don’t go away, even with evidence that they aren’t true. No one knows the cause of schizophrenia, but scientists have found some information on the symptoms of schizophrenia by studying the brains of schizophrenic patients.
There are several brain structures that are affected in patients with schizophrenia. The prefrontal cortex is at the very front and top of the brain, and it helps people think logically and organize their thoughts.Many studies have shown that people with schizophrenia have less activity in their prefrontal cortex.
This may be one reason that they suffer from delusions; after all, if they aren’t using their prefrontal cortex as much as most people, they aren’t using the part of their brain that induces logical thinking. Some schizophrenics also suffer from disorganized thought patterns. Since the prefrontal cortex also helps organize thoughts, less activity in that area might be a cause of disordered thinking, as well as delusions.Studies have also shown that schizophrenic patients suffering from hallucinations show brain activity in the visual and auditory cortices. These areas of the brain process vision and sound information from the eyes and the ears. In schizophrenics, the brain acts the same way whether the patient is seeing or hearing something real or just hallucinating. In other words, the hallucinations are as real to a schizophrenic’s brain as reality.
The basal ganglia is located deep inside the brain, and it involves movement and thinking skills. Some studies have shown that patients with schizophrenia have larger basal ganglia than normal people. This might affect the movement patterns of schizophrenics, who often have motor dysfunctions.
Another brain structure that is different in patients with schizophrenia is the amygdala. The amygdala is the part of the brain that is responsible for basic feelings, like fear, lust and hunger. Patients with schizophrenia often have little emotion, and not surprisingly, the amygdala is smaller in people with schizophrenia.
After all, if the part of the brain that is in charge of emotions is small, then chances are you won’t feel emotions very strongly.
Besides brain structures, there are other differences in the brains of schizophrenics and normal people. Specifically, there are some neurotransmitters that are different in the brains of schizophrenics. Think of neurotransmitters kind of like telephone wires. They are chemicals in the brain that carry messages from one part of the brain to another. That’s how the parts of the brain talk to one another.
There are many different neurotransmitters, and they all work in different ways and sometimes in different parts of the brain. Just like some telephone wires stretch all the way around the world, and others only go around the block, some neurotransmitters move between many different parts of the brain, while others stick to just a few specific areas.Dopamine is a neurotransmitter that is often associated with schizophrenia. Among other things, dopamine pathways are responsible for feeling pleasure. Dopamine is also a neurotransmitter that links the basal ganglia with the prefrontal cortex.
Remember that both of these are involved in thought processes, so dopamine helps people organize their thoughts.One type of symptom of schizophrenia, called negative symptoms, is the absence of something normal. For example, people with schizophrenia don’t feel emotions, which normal people do, so that is a negative symptom. Other negative symptoms include loss of motivation and an inability to feel pleasure.If you’ve been paying attention, you probably noticed that I just said that people with schizophrenia don’t feel pleasure, and that dopamine is responsible for making people feel pleasure.
From that, I bet you can guess that dopamine levels in schizophrenic patients are different than normal people. In some areas of the brain, dopamine levels are lower. Many of the negative symptoms of schizophrenia could be explained by low dopamine levels.
In other parts of the brain, dopamine is actually higher than normal. This may help explain hallucinations and delusions in schizophrenic patients. Explaining the symptoms of schizophrenia according to levels of dopamine is called the dopamine hypothesis of schizophrenia.
Schizophrenia is a psychotic disorder that includes hallucinations, delusions and negative symptoms, like a loss of pleasure or flattened emotions. There are several areas of the brain that are involved in schizophrenia.
Lower than normal activity in the prefrontal cortex might be the cause of delusions and disorganized thinking in schizophrenics.Hallucinations might be caused by too much activity in the visual and auditory cortices. The basal ganglia might be responsible for the motor dysfunctions in schizophrenia, while a smaller amygdala could be responsible for the flattened emotions. In addition to these parts of the brain, levels of the neurotransmitter dopamine might be responsible for some of the symptoms of schizophrenia, a theory that’s called the dopamine hypothesis of schizophrenia.
After viewing the video lesson, you should be able to:
- Recognize the fact that schizophrenia can cause hallucinations, delusions, lack of pleasure or deadened emotions
- Understand that schizophrenia affects the visual and auditory cortices, the basal ganglia, amygdala and changes in dopamine levels in areas of the brain