When life is busy, it can be hard to stop and appreciate the significant moments as they occur. This is hard even when life is not busy — busyness just makes it more difficult. When life is moving fast it’s hard enough to just keep up, nevermind appreciate the moments as they occur. Busy or not, life is always in motion; the moment always fleeting, always running away from us. In Unweaving the Rainbow, Richard Dawkins writes it feels to him as though “the present moves from the past to the future, like a tiny spotlight, inching its way along a gigantic ruler of time.” If we apply this analogy to life in medical school, the spotlight accelerates to a breakneck speed, careening down the ruler like a runaway freight train. Avoiding academic failure requires some form of running alongside the train; pausing to drift at its side for a moment’s contemplation is easier said than done. Learning to drift in this way is a skill that requires diligent effort and discipline.
It occurs to me that many people — medical students or otherwise — feel that they’re on the losing end of the race with the runaway freight train. Most people I talk to feel there aren’t enough hours in the day to accomplish all they hope to. Medical school only exacerbates these sentiments, as our schedules are packed with courses and extracurriculars and riddled with exams. For example, today’s Neuroscience midterm marks the sixth exam in just slightly more than two weeks. In this time there was the Cardiovascular System final and the Respiratory System final, midterms in Clinical Reasoning and Population Health, a two-station Objective Standardized Clinical Exam (OSCE), and the above-mentioned Neuroscience midterm. We don’t get time off for exams; these were all scattered amongst the usual 9 – 5 schedule of coursework. This fast pace makes it hard to stop and, as they say, “smell the roses”. This is unfortunate, as big events are happening all the time! In the past four days, for example, I was honoured to participate in my first surgery (obviously a very minor role, but still exciting), clinically examine strangers for the first and second times, and perform Christmas carols alongside several classmates for the patients of the Children’s Hospital. These moments are all worthy of reflection. I could probably write about any of them, but instead I’ve chosen a different topic: somewhere in the past weeks’ busyness was my first hands-on experience with the human brain.
Part of the curriculum of our modular courses, the ones that teach us about the various organ systems, is to learn the relevant anatomy of the systems. We’re in a 4-week neuroscience course right now; neuroscience entails neuroanatomy. Our education in anatomy includes hands-on lab sessions with human specimens that have been generously donated to our program (this thought alone is grounds for significant reflection). Our first neuroanatomy session was roughly two weeks ago. The supervisor of my upcoming research project was one of the instructors. Anxious not to appear incompetent, I had been up late into the morning hours cramming my brain full of as much neuroanatomy as it could hold (a situation that only now strikes me as ironic.) We entered the lab to find rows of tables, each with a skull on one end and a large bucket on the other. The class had been split into groups of six, and each group was given one skull and 1.5 brains — one full brain, and one single-hemisphere (my group was awarded a left hemisphere). The brains had been placed into the buckets and were afloat in a preservative bath. My proximity to the bucket nominated me for the task of reaching in and removing the brains (I was feeling fairly eager, so this worked out well). Armed with our printed instructions and under the guidance of several circulating instructors, we set to work on the task of hands-on study.
Before I carry on here, a quick word on the brain. The brain sends electrical impulses throughout the body; these impulses control the body. That, in a sentence, is the nervous system. One special type of cell, the neuron, is responsible for both the generation and the conduction of these signals, both inside the brain and out. There are roughly one hundred billion (100 000 000 000) neurons in the human brain. Most of these brain-dwelling neurons send signals to one another, forming the complex circuitry of the brain. Some send signals through the base of the skull into the spinal cord, itself made of neurons, which projects neurons to all the other sites of the body. Whether current does or does not flow from one neuron to another is the basis of the brain’s computational abilities. The site of connection between two neurons, through which a signal may pass, is called a synapse. Each neuron in the brain is linked up to about 1000 other neurons, making for a total of one quadrillion synapses (a million billion, also written 1015 or 1 000 000 000 000 000) in the average human brain. This is a staggeringly large number. It’s not surprising that the brain is so complex, given its remarkable capabilities. What is surprising is the ordinary appearance of the brain.
I’m not sure what I expected of the first meeting between my hands and a brain. I hadn’t given it enough forethought to have any specific expectations, but in retrospect I was anticipating the awesome complexity to be somehow indicated by the experience. This expectation was not met. Holding a brain in the palm of my hands was definitely a thrill, but the magnificent complexity I knew to be present was not able to be deduced by mere observation. Had I not been told it was so, I would have had no idea I was cradling the most complicated object in the known universe. This is because the brain, like so much of the world, doesn’t look like what it really is. This vast network of a hundred million billion connections, through each of which electricity either does or does not flow at every given millisecond, whose circuitry controls the body and produces the mind, appears to be scarcely more than a folded-up piece of meat.
This relates to a fact about the limitations of our sense organs. Our sense organs, powerful as they may be, evolved to detect a limited range of phenomena — specifically, medium-sized objects moving at medium speeds — and even within these constraints, quite a lot of what goes on is unavailable to us. Vision, our sense for detecting electromagnetic radiation, allows us to see only the tiniest fraction of electromagnetic radiation that exists in the world. Our sense of smell picks up only a small fraction of molecules that exist. The model of the world created in our brains is powerful, extremely useful for survival, and often tremendously beautiful, but it has many notable limitations. Certain things are simply beyond what we can expect of a brain built by natural selection. The realm of the microscopic was unavailable to our ancestors and so unavailable for the action of natural selection, therefore we’d expect events on this scale to be beyond what we can probe with sensory experience. The complexity of the brain itself is realized on a microscopic scale, so it’s unsurprising that this affair is hidden to casual observer. In short, evolution wouldn’t be expected to build a brain capable of appreciating the brain. The world we experience is beautiful, but the true world is much more beautiful than we can appreciate by sense alone. Thankfully, we have science to take us beyond the realm of sensory faculty.
Returning to the earlier topic of mindfulness: not every day will contain dramatic milestones, but every day contains something worth appreciating and reflecting on. It’s up to us to be mindful and watch for these things. The path to appreciation, to happiness, always leads through the present moment, because the present moment is all we really have. As author Marianne Williamson puts it, “No matter what time it is, it is always now.” Life is ultimately the sum of a long series of present moments. In his talk Death and the Present Moment, neuroscientist and philosopher Sam Harris elaborates on this point:
“The past is a memory; it’s a thought arising in the present. The future is merely anticipated, it’s another thought arising now. What we truly have is this moment…and this. And we spend most of our lives forgetting this truth, repudiating it, fleeing it, overlooking it, and the horror is that we succeed. We manage to never really connect with the present moment and find fulfillment there, because we are continually hoping to become happy in the future. And the future never arrives.”
Thank you all for reading. Please comment below! I wish you all the best with your future happiness and mindfulness.