BRAIN CHEMISTRY AND EMOTIONS: PART 2
Mental disorders and Neurotransmitters
Neurotransmitters play a very critical role in modulating emotions in the brain. If the levels of these neurotransmitters are not optimally balanced in the brain, it may result in some serious problems. A feeling of depression or anxiety or mood swings can be traced back to the lack of a balance in the neurotransmitter levels.
Most of the therapies that are given to individuals suffering form such disorders are aimed at restoring the balance in neurotransmitter levels. For example, most of the anti-depressants prescribed to patients suffering form major depression, are aimed at stimulating the neurons to release dopamine or serotonin. These drugs achieve this by a number of ways. One of the way they act is by blocking the dissipation of these neurotransmitters causing them to stay in the brain for longer periods of time. This raises the apparent levels of these neurotransmitters in brain and improves mood.
The anatomy of emotion
The brain is a big organ weighing in at almost 3 pounds. It is as complex in its anatomy as it is in function. Various areas of the brain are responsible for eliciting and controlling various emotions. The most important part of your brain for processing emotions is called the Limbic System. It is composed of many parts including amygdala, hippocampus, thalamus and basal ganglia. Amygdala is the most important part of the limbic system that evaluates the emotional value of an incoming sensory input. It is also the ‘fear center’ of the brain and plays a crucial role in processing the response to the fear stimuli. Many studies have shown that a damage to this part of the brain can abolish the perception of fear altogether.
The hypothalamus, another part of the limbic system controls the involuntary response to many emotions. For example, if you are excited or anxious, your heart beat is increased or your palms are sweaty, all these responses are mediated by the hypothalamus.
The hippocampus is responsible to evoke emotions integrated with certain memories. The nostalgia that you feel when you think about the good old times is controlled by the hippocampus. The hippocampus is also responsible for converting the short term memories to long term memories.
The brain on a whole is composed of two identical halves one on each side- left and right. You might have heard about right and left brain, that refers to these hemispheres of the brain. Each of the halves performs different functions and is associated with the processing of different information. For example, the left part of your brain is responsible for drawing more literal conclusions such as meanings of words, or mathematical formula while the right side is more creative dealing in less concrete ways.
As both sides are working in unison, the emotions are pretty well controlled. If we have to generalize, and remember it is an oversimplification, the right hemisphere identifies a stimuli and the left brain interprets the meaning. The system works perfectly as the jobs of receiving and interpretation are clearly designated. However, sometimes if one of the hemisphere is not able to perform its function, the results can be very destructive. For example, if there is no left brain to interpret the emotions, the right brain will be overwhelmed with a lot of emotional stimuli and would not know what to do.
There is plentiful scientific evidence regarding the effect of a damage to either hemisphere. Patients having damages left brains are more prone to depression and are suicidal. Their right brains are overwhelmed with negativity and they don’t have the left brain function.
Memory is also a big part in perceiving emotion
As we all have experienced, certain memories bring a feeling of joy and certain bring about sorrow. These memories when elicited, can cause the limbic system to perceive them as emotional stimuli and the result is precipitation of an emotion.
As we saw earlier, the short term memories are transformed to long term ones in the hippocampus which are then evoked due to certain visual or auditory stimuli.
Many psychologists have successfully used this system to treat patients suffering form severe depression. If you can evoke a good memory in a depressed individual, it can lead to the release of dopamine and serotonin and make the patient feel good. Everyone of us tries this at their own level. If you are feeling bummed out, looking at photos of your loved ones and reliving some memories can help elevate your mood greatly.
Something to take home
The brain is like a complicated but very finely tuned machine. It plays a crucial role in eliciting and interpreting emotions and feelings. Hopefully you have learned something new about how your brain is involved in experiencing emotions and how some disorders affect the balance in brain chemistry.
Be sure to check in next week for the last installment of “Brain Chemistry and Emotions: Part 3”.