The Brain & Emotions
The human brain is the most complex organ in our bodies and it is made up of about 100 billion nerve cells. It gathers all the information from the world around us using the 5 senses of sight, touch, hearing, taste and smell. It also organizes and interlinks this information and then stores it. Emotions are an internal factor, which are affected by the input from our senses, and emotions tell us what all this information means to us. For example, when we see a cute baby, we feel happiness and this tells us it is good thing.
Emotions are an essential part of our everyday lives. Our behaviour is based upon our emotions. In the past, our ancestors depended on their emotions for their survival, however, in the modern times, our emotions control other things like our relationships and lifestyle. Our decisions are also controlled by our emotions, especially decisions based on our intuitions.
For example, when it gets dark, our eyes tell our brain, brain creates fear and as a result we switch on the lights. Emotions are controlled by varying levels of chemicals in our brain, called neurotransmitters. These chemical messengers are used for communication between nerve cells as well as between different brain regions.
When we are in a dangerous situation, certain areas of our brain are flooded with one such chemical, called adrenalin, which changes our behaviour and makes us act fast and ‘fight or flight’. Mostly all animals produce basic emotions like fear and anger, humans have also developed a set of higher social emotions like guilt, sadness, pride, shame etc.
Major Brain Structures Involved in Emotions
Our emotions are controlled by a major network of the brain, called the limbic system. It controls our emotions, and thus it also controls our moods and decisions. The limbic system is made up of three main components, namely, hypothalamus, hippocampus and amygdala. Experiments with monkeys in the 1930s have found that the amygdala is responsible for associating emotional significance to things, incidents and memories. The hippocampus regulates our behaviour with respect to our emotions, while the hypothalamus controls autonomic biological functions like sweating, heart-rate, breathing etc., and hormones that match with our moods and emotions. For example, when we are excited, our heart rates increase or when we are scared, we start sweating etc. However, in our day to day lives, our behaviour is also controlled by other networks as well. This is to make sure that all our decisions are not emotional and that the important decisions in our lives are also practical. The autobiographic memory network and the cognitive control network work in a complimentary manner to maintain the balance between self-reflection or ‘thinking about ourselves’ and the attention and concentration required to complete tasks. This balance is extremely important to keep us focussed on the important aspects of our lives. In case of people with imbalanced networks, they end up suffering from mood disorders.
Neurotransmitters and Emotions
Neurons in our brain are not connected to each other, thus they communicate with the help of brain chemicals called neurotransmitters. Neurotransmitters chemically connect our brain to our body and regulate not only our emotions and mood, but also other important aspects of life like memory, cognition, physical activities etc. Our brain needs proper nutrients in order to produce all the necessary neurotransmitters and in the right amounts, as maintaining the balance of different neurotransmitters is very important. Imbalance in the level of different neurotransmitters causes numerous physical and psychological problems like fatigue, insomnia, obesity, pain, mood disorders, addictions, depression, anxiety, compulsions etc. The balance of different neurotransmitters is also what determines our moods and emotions. The four main neurotransmitters that control our emotions are Serotonin, GABA, Dopamine and Norepinephrine. While Serotonin and GABA are inhibitory neurotransmitters or ‘calming’ neurotransmitters, dopamine and norepinephrine are the excitatory or ‘stimulating’ neurotransmitters. These two groups are complimentary to each other and their levels balance each other out. In addition, there is Oxytocin, which is also known as the ‘love’ hormone/neurotransmitter. The images below show how the changing levels of Dopamine, Serotonin and Oxytocin change our feelings and the associated emotions.
Expression of Emotions
200 years ago Charles Darwin wrote a book called ‘Expression of Emotion in Man and Animals’, where he reviewed the literature about facial, vocal and linguistic expression of emotions, in humans as well as animals. However, considerable progress has been done in this field since then. Happiness, sadness, fear, surprise, disgust and anger are the six primary emotions identified by a famous psychologist, Paul Ekman and his team. Each of these emotions have corresponding facial expressions. Emotions are expressed not only by facial expressions but also through speech and body language. Facial expressions for these primary emotions are more or less common and innate across different countries and cultures. It can be said that these basic emotions are sort of hard-wired in the human brain. However, managing our facial expressions depends on certain cultural rules, known as display rules. For example, in the Japanese culture it is considered offensive to express negative emotions in the presence of someone with authority. Thus in a situation when a Japanese person will be experiencing a negative emotion, like disgust or sadness, but a person of authority is present, he will try and not express it on his face. Apart from cultural differences, some difference in emotional expression has also be reported between men and women. This difference is also observed socially. Women are more expressive when it comes to happiness, sadness or love, while men express anger more. These differences are not absolute, but largely based on behavioural studies and observations. Thus they are mere generalizations and depend mostly on cultural norms, social situations, upbringing and gender roles.
Influence of Drugs on Emotions
Drugs usually refer to psychoactive chemicals like alcohol, cannabis, ecstasy etc., which people use recreationally. They regulate our mood by changing our emotional states. For example, alcohol is known to induce sadness leading to a depressing feeling, while cannabis can induce extreme happiness for a short period of time. How do these drugs actually work? They interfere with the neurotransmitters or brain chemicals and thus mix up our emotions. As a result, such drugs also affect our behaviour, and not necessarily positively. In most cases, people end up making bad decisions under the influence of drugs. Sometimes using psychoactive drugs also leads to anxiety and paranoia along with other psychiatric problems, which makes the experience extremely unpleasant. Then why do people use such drugs? In addition to the negative effects discussed before, using such drugs also has certain short-term effects which can be enjoyable. It causes a certain ‘high’ which is temporary and passes once the drug leaves our system. Most people use drugs seeking this short term ‘high’. Furthermore, the hangover period after any kind of ‘high’ makes us feel tired, irritated and also physically sick. The positive emotions of the ‘high’ die down and they are replaced with negative emotions like sadness, anger and apathy.