Aside from mathematics, I have other interests. Ever since I started to use my brain for mathematics, I am interested about how thinking works. Since problem solving is my day job, I have plenty of opportunities to observe my cognitive processes and I have a passion for optimizing my brainworks. Thinking about thinking is a very interdisciplinary field, ranging from neuroscience to psychology, and I find a lot of joy in reading about it and trying to adapt it in practice. Why not write about it then? I decided to write about my neverending quest in exploring and enhancing the workings of my mind. I am no brain scientist, merely a brain user (most of the time, at least), therefore these posts will serve as a “How to use your brain 101”, rather than an exquisite scientific investigation.

There is a wide range of physiological and psychological tools which can help to enhance your cognitive functions. This time I am going to talk about neurotransmitters and how to exploit the hell out of them.

1. Neurons and their signals. Ever thought about what is thought? How it forms and how it is stored in your brain? Looking at it from a natural scientific viewpoint, thoughts are nothing else but chemical processes and electrical impulses in your brain, created and channeled by nerve cells, or in an other name, neurons. Neurons can create and transfer electrical and chemical signals, which represent information in your brain. They look like this.

The tentacles on the right are called axons, they connect the cell to other nerve cells. The smaller tentacles on the left are called dendrites. These are the sites where other neurons connect to. An average adult human brain contains $86 times 10^{9}$ neurons. This is a lot. You can find a list of animals by number of neurons at wikipedia. The number of connections are even larger, therefore your neural network can store and process a huge amount of information. The neural network of a mammal looks something like this.

Basically, the rule of thumb is

$text{larger network} + text{more connections} = text{more smart}$.

In the following, I am going to talk about the latter component, namely the connections and the quality of these connections.

2. Neurotransmitters. The electrical and chemical signals travel between neurons. This process is called neurotransmission. An axon is not directly connected to a dendrite of an other neuron, but there is a small gap called synapse in between them, where various chemical processes happen. The signal is transfered across the synapse by the aid of neurotransmitters. The whole process looks like this.

In order to things go smoothly, you should have a decent supply of neurotransmitters and an abundant number of receptors.

I am going to talk about three neurotransmitters: dopamine, serotonin and acetylcholine.

2.1. Dopamine. Ever felt unmotivated, depressed, lacking sexual drive, or having trouble focusing? These are some of the symptoms of dopamine deficiency. A note of caution however, before I proceed. If you lack dopamine you have these symptoms, but it is not necessarily true the other way! Depression or lack of motivation and focus can be caused by several other problems, even psychological ones.

So there is this tiny molecule, which looks like this.

Dopamine is connected with the so-called reward pathway. It is released when you experience something that gives you joy, for example having sex, eating a bar of candy, proving a mathematical theorem, etc. (Ok, I admit, the latter may not work for everyone.) For me, occasionally studying something completely else than mathematics gives me a huge dopamine boost. Right now, collecting data and researching this topic has a very uplifting effect on me, which enhances my dopamine level. In fact, one of the very reason why I started this blog is to hack my dopamine levels.

Although releasing a lot of dopamine is a thing everyone should yearn, there is a catch. Having more dopamine gives you much joy in itself through some of its beneficial effects, so having some of it should cause to release even more of it? No. Simply saying, the more expected the reward is, the less activation can be seen in the dopamine neurons. This phenomena is called reward prediction error. Adopting a practical viewpoint, my point is this. Stuffing candy into yourself, shopping extensively or surfing online the whole day does not gives you much reward, and it certainly does not enhance your life. The good type of joy can be found in the small things. A really interesting article you find. A kiss from your darling in the morning. Understanding a theorem for the first time. Discovering a small pattern in the mathematical objects which you work with at the moment. The list is long, and I hope you get my point. Setting small goals and completing them is also a good idea to enhance motivation through the workings of your neurochemistry. If, for example, you want to complete a marathon, you should set milestones which inevitably lead to your goal. Focus on the next few hundred yards instead of only thinking about the whole 26 miles.

Bottom line is, the beneficiary effects of dopamine includes enhanced cognition, improved memory and a boost in motivation. Dopamine deficiency can cause depression, lack of motivation, lack of focus and problems with motor skills. There are some medical conditions related to dopamine, for example Parkinson’s disease or attention deficit disorder. The medication for these directly increase dopamine levels in the body.

The level of dopamine can also be increased by, for example, eating right, having a lot of physical exercise, getting plentiful of sleep and using the reward system of your brain cleverly. Using your reward system is kind of a balancing act, but hey, you have plenty of time to try!

You can find a ton of information about dopamine online. For further research, I recommend this post on http://blog.idonethis.com.

2.2. Serotonin. Surely you must know what it is like to have a nice talk with your friends. You are at the pub or at a get-together, talking about everything, someone suggests an interesting topic, you debate, listen to each other’s argument, reach a conclusion, then sit back and have an another beer. You feel accepted and cared for. The satisfaction what you feel from connecting to each other and sharing your thoughts is related to serotonin being released.

This little molecule is connected with social status. The bottom line is clear. If you have good friends you can count on, are appreciated in your workplace, and generally feel that you are a valuable member of society, you are happy. If your personal life is messy, you feel dismissed and looked upon at work or if you have no social life at all, you are not happy. This feeling of happyness or nonhappyness are caused by the level of serotonin in your body. Lack of serotonin can cause depression and even suicidal behavior.

Serotonin also affects risk-taking behavior, which is important in many aspects of life, for example being a scientist. How are going to tackle the next hard question nature (or in my case, mathematics) throws at you if you think you are not enough, if you feel like a failure, if you think you are underappreciated by your collegaues, or if you feel unsuccessful? You probably won’t.

It has been shown in a recent research paper that low levels of serotonin in humans cause depression and it influences many decision-making processes, for example, depletion of serotonin precursor L-tryptophan causes decrease in cooperating behavior in the game prisoner’s dilemma.

What can you do to have a decent level of serotonin? Well, for example, start by making friends with people who you look up to and who feel the same about you. Then of course, there is also the method of sleeping much and eating right. You can research online for nutrition advice regarding your serotonin levels.

For further reading, I recommend two blogposts. One is a post at neuroecology titled How social status affects your brain, the other can be found at Brain Posts titled Serotonin, Social Interaction and Making Decisions.

2.3. Acetylcholine. Acetylcholine is probably the least famous of these three transmitters, but it is nonetheless very important. To emphasise this, a fun fact. The nerve gas sarin acts by messing with your acetylcholine level. Muscle control is impared as a result, which ultimately disables your breathing functions, at which point you suffocate.

Aside from muscle control, having a decent supply of acetylcholine enhances your responsiveness to visual, auditory and somatosensory stimulus. (Somatosensory system is just a fancy name for touch.)

Alzheimer’s disease is associated with acetylcholine. It seems that it is caused by problems in the density of synaptic receptors. (That is, you may have enough neurotransmitters, but you cannot process them decently.)

Optimizing your acetylcholine level can be achieved by correct nutrition, exercise and a good amount of sleep. If you paid attention, you can notice that these three methods appear in every “how to boost my levels of…” section. These things should be taken seriously, if you want a productive life.

3. Summary. The synergistic effect of these three neurotransmitters are well summarized with this figure.

Bottom line is, these knowledge should be used to your advantage. It was an illuminating experience for me when I first learned about neurotransmitters and their effect. Realizing that some of my problems (in my case, lack of attention) can be caused by chemicals and not some tragic character flaw was kind of uplifting. Paying attention to your neurotransmitters constantly can be hard at first, but once you develop healthy mental and physical habits, these things take care of themselves.