We’ve all seen the crazed look in the eyes, the disheveled hair and yellowed teeth of the chronically dependent, as they shuffle towards their saving grace first thing in the morning. A long line of McGill students, praying to the altar of Tim Horton’s during their most trying time. Starving artists shelling out $4.00 a pop at independent coffee shops in Mile End, praying to Kaffeina (the Roman goddess of coffee) that the brown elixir served by the hip baristas will hold a cure for their existential angst. Have you ever wondered what is responsible for the rush Starbucks provides, or been curious about the active ingredient in the morning drink our culture so adamantly reveres?

The answer: caffeine. This simple 24-atom molecule is the most widely-used drug in the world. The two most popular beverages worldwide (not including water) are tea and coffee, in that order. Coffee contains twice the amount of caffeine as tea per serving (100 mg to 50 mg, to be exact). Many soft drinks, including both Coke and Pepsi, also feature this intoxicating molecule, not to mention the multitude of energy drinks students and truck drivers alike rely on to get them through many a long night.

Caffeine is widely renowned for its association with enhanced thinking abilities. Its perceived effects include improved efficacy, feelings of awakeness, and increased creativity. These attributes have rendered it the chosen substance for sleep-deprived thinkers for centuries. What is it about this simple substance that lends it the ability to increase concentration?

To learn how caffeine keeps us alert, we first need to understand how we get tired on a neural level. Neurotransmitters are chemicals that carry messages between neurons, the cells that compose your brain. Adenosine is produced in every neuron throughout the day, as a by-product of cellular processes that consume energy (in the form of ATP). Adenosine binds to A1 receptors in your nerve cells, telling the neuron to stop releasing excitatory neurotransmitters like glutamate, serotonin, and dopamine. Since there’s no excitatory signal in transmission, the resulting message is one of inhibition: adenosine basically tells the brain to chill out. This is what induces feelings of tiredness at the end of the day!

The structure of caffeine is similar to that of adenosine, similar enough to bind to the same A1 receptors. However, caffeine is structurally different enough that instead of activating these receptors and transmitting the “tiredness” message, it actually blocks the signal and results in a lack of fatigue, acting as an antagonist for the A1 receptor. Since adenosine can’t bind, there are more of the excitatory neurotransmitters floating around the brain, because their production isn’t down-regulated. Increased levels of glutamate, serotonin, and dopamine lead to more neurons firing: in other words, more of the brain is active, which could lead to an improved ability to focus.

Despite its association with locations of business rather than pleasure, caffeine is a recreational drug with similar effects to other less socially acceptable substances. Like any psychoactive drug, increased intake of caffeine causes the body to develop tolerance: more A1 receptors are created when you drink coffee consistently, so you have to drink more to feel the same “rush”. As a result, foregoing regular caffeine use renders it more effective. However, this isn’t easy to do, because in addition to tolerance, caffeine can cause chemical dependence. Caffeine withdrawal can occur 12 to 24 hours after most recent use, with symptoms that include headache, depression, and fatigue. This is one reason why most people choose to intake first thing in the morning – to stave off withdrawal.

In addition to chemical dependence, caffeine has been found to enable some psychological addiction. It is the increase in the level of dopamine, the neurotransmitter most tightly linked to the reward pathway in the brain, that gives many drugs their “high,” and causes them to be addictive. By inhibiting its downregulation, caffeine increases the amount of dopamine floating around, and is slightly addictive as a result.

Caffeinism is the technical term for chronic addiction to caffeine. I think it sounds more like the name of a cult that worships caffeine, which, if anything, seems to be more prevalent in our culture. Faith in coffee is all fine and good, but it’s not magic bean water – it’s hot caffeine water, and science can tell us how it works!

Sources – all information taken from this book:

Braun, Stephen. Buzz: the Science and Lore of Alcohol and Caffeine. Oxford University Press, 1996.

Reality is Perception

“Life’s what you make it, so let’s make it rock!” – Hannah Montana, 2007.

Our nervous system is what allows us to think, to plan, to make decisions and take action based on our perception of the world. Our brains are able to process massive amounts of data from the universe we inhabit, and the combination of chemical signals and electric potentials allows us to interpret the environment in which we live. Despite the large amount of data we are able to process, we are not directly connected to the universe the way single-celled organisms are, through a simple membrane. Instead, all of our sensory input is organized and processed by specialized areas of our nervous system. There is an absurd amount of information incoming all the time, so a significant portion of our brains are devoted to determining what’s worth processing. We are only consciously aware of the input we attend to. Subsequently, our world view is determined by the input we attend to, which form our observations of the world. The decisions we make are based on our respective interpretations of the world. The images we remember are conjured by our brain, not accurate reproductions of the universe. Since unattended sensory input is not remembered, it cannot factor into our perception of the world, and it therefore cannot have any impact on our decision-making process. Awareness is key because it determines our outlook which determines the actions we take which impact our environment are based on the decisions we make.

The only objective truth we can know is that all we know is what we experience. Everything we know about the world is from induction – we assume it’s true because our experience is all we have. We make assumptions and, if our experience never contradicts these assumptions, we accept these assumptions on lack of counterevidence. This is possible because all the information our consciousness is exposed to is interpreted by our brain.

Information comes in through our five sensory organs: touch, smell, taste, hearing, and seeing. Each is experienced in the sensory cells, then the information is transmitted to nerve cells in the brain. All of the sensory imagery except smell is then processed in the thalamus, a specialized part of the brain. In the cortex of the brain, there are many different areas that process and organize sensory imagery, especially visual and auditory imagery. Our brains alter the incoming information, organizing it to form a worldview. Our belief systems compose our worldview – we see what we think we are going to see. This is why outlook is critical. We process information based on what we attend to.
There are many interesting related psychological phenomena – inattentional blindness is a process whereby people don’t notice something, often something obvious, in their environment because they are busy attending to something else (demonstrated in this video).

Life, which is composed of your personal experience, really is what you make it to be. This is the single most important lesson I’ve learned over the past year, over and over again. I still forget sometimes, but my life is always better when I’m able to remember that I have the power to create the world I inhabit.