[ Ben’s Note: This is a Guest Post from Emiel Bakker of Focus Supplements. ]
After the movie ‘Limitless’ came out in 2011 there has been a surge of interest in the domain of cognitive enhancement. The movie portrays the main character as a stagnant writer whom after consuming a small pill of NZT-48 unlocks all of his brainpower instantly. He is able to learn and analyze situations at an astonishing rate. The movie sparked a surge of interest in the domain of cognitive enhancement because it portrays a situation we can all relate too. Let’s be honest, we have all been in a situation similar to the main character of Limitless. Life just isn’t going as smooth as it could and you wish you could take something that would propel you into an enhanced state of mind.
Now before you continue reading this article, keep in mind that the movie ‘Limitless’ is pure fiction, and nothing even close to NZT-48 exists. So enter this article with a realistic mind-set because cognitive enhancement is a slow, steady and safe long-term process unlike NZT-48. Since most of cognition enhancement occurs in the brain, this article will begin with a brief intro into some neuroscience terms that will make reading this article and doing further research into cognitive enhancement a lot more rewarding.
Neurons are one of the cells that make up the brain. They have the ability to transmit information via electrical activity and chemicals called neurotransmitters. There are many different types of neurons each with their own specialized function. As can be seen in the image above, most neurons consist of two distinct parts, dendrites and axons. In the image above, the dendrites are located on the left and closely resemble tree branches. The dendrites receive signals, from other neurons. The axon, located on the right in the image above, sends out signals to the dendrites other neurons.
Communication between neurons happens at a structure called the synapse as seen in the image below. This process is called neurotransmission; it is both a chemical and an electrical process.
A message originates at A as a chemical signal, in the form of a neurotransmitter. The neurotransmitter is synthesized at 1 and is then packaged into vesicles (2). The vesicles then travel down to the cell membrane (7). The vesicles lodge onto the cell membrane and, in response to a calcium influx through the channel labelled with the number 6, open through a process called exocytosis. The neurotransmitters now freely float around in a fluid filled space called the synaptic cleft (4). The neurotransmitters can then bind to the neurotransmitter specific receptors indicated by the number 5. Once the neurotransmitters bind, an electrical signal is produced in B. This electrical signal is called an action potential and causes the further release of more neurotransmitters onto other neurons. This process keeps repeating itself at an astonishingly fast rate and is how different brain regions produce activity and are able to communicate with each other. Any neurotransmitters left over in the synaptic cleft (4), either gets broken down by various kinds of enzymes or get taken up by the neuron at the location indicated with the number 8.
The main goal in cognitive enhancement is usually to enhance or decrease neurotransmission for certain neurotransmitters. The neurotransmitters that receive the most attention in regards to cognitive enhancement are depicted in the image below.
To make these neurotransmitters easy to understand, their functions are often highly generalized which often is not the case. For example a common misconception is that serotonin is the ‘feel good’ neurotransmitter, dopamine is the ‘pleasure’ neurotransmitter and ‘acetylcholine’ is the ‘learning’ neurotransmitter. Although there is some truth to these misconceptions, the reality is that neurotransmitter systems are incredibly complex and still somewhat misunderstood. For example, there are currently 14 known serotonin receptors, some of which are responsible for making us feel relaxed and happy whereas others are actually responsible for making us feel the exact opposite. Due to the highly complicated nature of the neurotransmitters, this article will only expand on specific functions associated with the neurotransmitters within a given cognitive process, rather than giving an over generalized description of their overall function.
Major brain areas that affect cognition
Similar to the neurotransmitters, the functions of certain brain regions are often highly generalized. However, it is possible to make some accurate speculations as to the localized functions of certain brain areas. In regards to cognition it seems like two main areas are highly involved, the frontal lobe and the hippocampus. This however does not mean other areas aren’t involved in cognition, however it is the case that a lot of research into cognitive enhancement focuses on these two areas. The frontal lobe is highly involved in executive function and the hippocampus is highly involved in some stages of memory formation and consolidation.
It seems like the most promising avenues of cognitive enhancement lie in making major changes to an individual’s lifestyle, rather than immediately heading towards pharmacological interventions. This part of the article will discuss three major lifestyle domains, which seem to have the most impact on cognition: stress, diet and exercise.
Stress can be very debilitating when it comes to our cognitive function and thus controlling for stress in your daily life should be one of your highest priorities when it comes to increasing your cognitive function. As many of us have likely experienced, high levels of prolonged stress can shut you down. Your memory seems to be decreased, your quality of sleep goes down, you seem to be processing information slower and you’re far more likely to get agitated when something doesn’t go as well as you planned. However stress is not all bad, sometimes it can offer a boost in productivity and a sense of mental clarity. So it seems that stress follows something called a bell shaped response curve:
stress response in favour of enhanced productivity.When stress levels are too low, you’re far more likely to procrastinate and not get things done. When a deadline is approaching but you still have things under control, your stress levels are likely at an optimal level and productivity skyrockets. However when a deadline is approaching sooner than you had expected and you don’t have things under control, your stress levels will likely become too high and you’ll likely have a hard time focusing on the task at hand. It’s important to become mindful of this bell curve because once you understand the relationship between your personal stress levels and your productivity, you’ll be able to tweak your
Stress is linked to a collection of important hormones and neurotransmitters, which all interact with each other and due to this the neurology behind stress is incredibly complex. To create a simpler explanation of some of the neurology behind stress, we’ll look at a class of substances called adaptogens. Adaptogens can normalize the physiological and psychological response to stress (Khanum et al., 2005). Something all adaptogens have in common is that they normalize the increased levels of the stress hormone, cortisol, in response to increased levels of stress (Pannosian et al., 2007). This is very important because long-term exposure to elevated cortisol levels can damage the hippocampus, which as mentioned earlier is a brain structure that is crucial for the formation of memory. However short term exposure to elevated cortisol levels can actually aid the formation of memories (Pannosian et al., 2007). This further supports the claim that stress follows a bell shaped response curve and should give us all further incentive to regulate our stress levels in a smart and sustainable manner. Furthermore, all adaptogens seem to increase levels of a neurotransmitter called neuropeptide Y (NPY). Increased levels of NPY are associated with increased resilience to stress (Pannosian et al., 2007) and thus can further help us use our stress response in our favour. One of the most well-known and effective adaptogens is Rhodiola Rosea, which can be purchased here.
Another major factor involved with regulating our cognition is diet. The majority of the neurotransmitters are synthesized from compounds found within a properly balanced diet. All of the monoamines, which include dopamine, serotonin and norepinephrine, are synthesized from aromatic amino acids. For example, the aromatic amino acid L-tryptophan, which is found in high amounts in most protein sources, is responsible for the production of serotonin. Serotonin is a crucial component of our cognitive function and it has been shown that low serotonin levels within certain parts of the frontal lobe can decrease our cognitive flexibility (Clarke et al., 2004). Cognitive flexibility allows us to swiftly switch between modes of thinking and allows us to think of multiple concepts at the same time. Cognitive flexibility seems to be a major component of our learning ability. Serotonin levels can be maintained by eating high protein foods, however something to keep in mind is that the different amino acids in protein sources can block each other’s absorption. To circumvent this, in addition to a diet with adequate protein, one can supplement their diet with isolated L-tryptophan without a protein source and with a carbohydrate source in order to increase its absorption. You can purchase isolated L-tryptophan here. Another compound, which is found in a balanced diet, is choline. One of the most important neurotransmitters when it comes to cognitive function seems to be acetylcholine, which is synthesized from choline. Blocking certain acetylcholine receptors with a drug called scopolamine can cause major learning deficits (Preda et al., 1993), whilst activating certain acetylcholine receptors with nicotine can significantly boost our cognitive function (Barr et al., 2008). Choline is found in high amounts in egg yolks and many other whole food sources. One can also supplement their dietary choline intake with highly bioavailable choline sources such as CDP-Choline, to increase acetylcholine levels above what can be achieved through a balanced diet. You can read more about CDP-Choline here.
Finally regular exercise is likely the most important factor when it comes to increasing cognition. It can both regulate stress and regulate important neurotransmitter levels. Even more interestingly, exercise can keep our brains plastic, which means that it’s easier for our brains to change in response to cognitive stimuli. Like adaptogens, regular exercise can normalize cortisol levels (Anderson et al., 2013), leading to much of the same benefits as discussed earlier. Regular exercise also increases serotonin levels and activity in the brain (Anderson et al., 2013), again leading to much of the same benefits as discussed earlier. In addition to increasing serotonin levels and activity, regular exercise can also regulate norepinephrine levels. Norepinephrine levels in terms of cognition is important in the maintenance of focus, however similar to stress levels it follows a bell shaped response curve and interestingly enough increased levels of stress are associated with increased levels of norepinephrine (Chamberlain et al., 2013). Thus it seems that norepinephrine is one of the driving forces behind both the benefits and detriments behind stress. Being able to regulate norepinephrine levels via exercise can thus allow us to further capitalize on the benefits of optimal stress levels. Regular exercise also increases levels of a substance called brain derived neurotrophic factor (BDNF) in the hippocampus. BDNF is highly implicated in cognitive function because it is in part responsible for the growth of neurons and synapses in areas of the brain that are crucial to our cognitive functioning, such as the hippocampus. BDNF also plays a major role in the consolidation of long-term memories (Anderson et al., 2013).
Throughout this article it should have become apparent that enhancing your cognition is not as simple as just taking a small tablet. A lot of different factors are involved which require time and dedication to improve on. Cognitive enhancement should be a slow and sustainable process not just a quick fix with the risk of long-term adverse effects. Once you have some of the factors discussed in the article under control, you can start looking at more pharmacological interventions that enhance your cognition. A good place to start is here (https://www.reddit.com/r/nootropics/wiki/faq) in the FAQ’s section on the nootropics subreddit.
About the Author:
Written by Emiel Bakker on behalf of Focus Supplements.
Barr, R. S., Goff, D. C., Evins, A. E., Culhane, M. A., Jubelt, L. E., Mufti, R. S., . . . Freudenreich, O. (2008). The effects of transdermal nicotine on cognition in nonsmokers with schizophrenia and nonpsychiatric controls.Neuropsychopharmacology, 33(3), 480-490.
Preda L, Alberoni M, Bressi S, Cattaneo C, Parini J, Canal N, & Franceschi M. (1993). Effects of acute doses of oxiracetam in the scopolamine model of human amnesia.Psychopharmacology, 110(4), 421-426.
Panossian, A., Hambardzumyan, M., Hovhanissyan, A., & Wikman, G. (2007). The adaptogens rhodiola and schizandra modify the response to immobilization stress in rabbits by suppressing the increase of phosphorylated stress-activated protein kinase, nitric oxide and cortisol. Drug Target Insights, 2, 39-54.