1 de agosto de 2012

“Drinking from a firehose:” can research into the human mind help with medical school memorization?

I’ve come across many analogies that try to convey the amount of memorization required in medical school. The most popular is drinking from a firehose. One physician writer put it like this: “It was like being asked to enter a grocery store and memorize the names of every product in the store, their number and location, every ingredient in every product in the order in which they appear on the food label, and then to do the same thing in every grocery store in the city.”

In medical school, we talk in terms of “high yield” and “low yield” information. Basically, everyone accepts that it is impossible to know everything or even close to it, so medical school becomes an exercise in figuring out what is most important. For every conversation about memorizing, there are also a couple of self-deprecating quips about forgetting. I’ve had times where I studied something, took a short break, and then forgot what I was just reading. Is it sad? Yes. Demoralizing? Can be. But unique? Talking to other medical students, I’ve found the answer is a resounding no. The consensus on memorization among my peers is comically Lake Wobegon in reverse: here, everyone is convinced (s)he is below average.

Are we inherently bad at memorizing? Are we just not programmed to be effective at learning everything the modern medical landscape demands from us? I wondered about that. But more so, I wondered about solutions. If we ask for help, most of us rely on casual tips from those who have gone through the process before us, and we try to assemble diverse anecdotes into a feasible personal plan. But research into the human mind and its ability to remember is vast. And that knowledge says that memorization is a skill that can be improved upon with strategy and practice.
What of that knowledge can apply to medical training, specifically? Which techniques can help information stick – in ways that are meaningful, relevant, and ultimately useful for patient care?

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Chunking. Our short-term memory can store and retrieve a limited number of facts – and researchers have honed in that number. In 1956, cognitive psychologist George Miller published a paper providing evidence for seven being the magic number, plus or minus two. It was one of the most widely cited psychology papers ever, and Miller’s figures are ones that many in modern psychology circles still go by. What does that mean if you want to remember more than seven items? The solution involves breaking down – or “chunking” – larger sequences into smaller ones. For example, if you want to remember the ten digit sequence 6256493174, you could instead think of it as 6, 256, 493, 174. Or 62, 56, 49, 31, 74. Or some other combination, as long as it’s in a retainable number of chunks.

Does it work? In medicine, we constantly need to remember facts that relate to a particular umbrella subject. Chunking is useful as a guide in keeping relevant concepts together, within a range that is ideal for memorization. I know, for example, that if I am trying to remember bacteria, it helps to classify them into groups – with each group containing facts of nine or fewer items. In that sense, perhaps chunking is little more than a fancy way of saying organizing – with the additional recommendation of what size you should organize subjects into to increase your chances of retaining.

One issue is that chunking refers to a technique for short-term memory. In medical training, I care about knowing things for the long term. Can chunking still help? Psychologist opinion seems to say yes: chunking improves the transfer of short-term memory to long-term memory. Some have used the example of language to make this point, in that we regularly use single words or phrases to capture complex meaning and remember it in the long-term. Medicine uses similar principles. That is, whenever we have a medical term for a constellation of symptoms, a disease progression, or a type of treatment, we are actually chunking multiple concepts into a single phrase. Taken in reverse – a single medical term connotes multiple ideas. Medical language enables us to memorize better by having us memorize in chunks.

The bottom-line on the usefulness of chunking in medicine is that it’s a way of thinking consciously about something we tend to do naturally – organizing complex ideas into simpler ones. Having that conscious awareness of why condensing works can make the number of facts we are expected to learn in medicine less intimidating.

The memory palace. Picture some location you know well, such as the rooms in your house or the streets in your neighborhood. Now suppose you have to memorize a list of groceries. Start at the beginning of your location and walk forward, placing items at well-known landmarks as you go. Maybe you place a carton of milk at the foot of your stairs, a dozen eggs at the top, and a pile of apples next to the pillow on your couch. This technique is described well in Moonwalking with Einstein: The Art and Science of Remembering Everything, by Joshua Foer. The idea behind the memory palace is that we have an innate knack for remembering spatial layouts – supported by brain scans showing that spatial learning parts of the brain are used by people who win memory contests.

Does it work? Since you’re walking along a path, the memory palace works well for material that needs to be remembered in sequence. What topics in medicine might apply? Stages in a disease progression do the trick. The memory palace can also be useful in anatomy, a subject filled with order: which blood vessels branch into which, how nerves connect, and how layers of muscle and connective tissue lie – from top to bottom, front to back, and left to right. Additionally, the memory palace can be of use for lists where there is no order (such as the groceries); I would simply create a different walk for each list. In that way, any part of medicine I might “chunk” together, I could also place within a memory palace.

There are a few drawbacks. One is that the images that do the most for memory are ones that are most creative – or, as Foer puts it, most ludicrous. Crafting ludicrous images might be fun, but it is also very time consuming. Compounding the time investment is that many topics in medicine are not prone to imagery the way groceries are. Imagine biochemistry, for instance, where I am trying to remember the steps of signal transduction: Ras activates RAF, which activates MEK, which activates ERK. How can I place this alphabet soup of acronyms in my house? Since Ras comes from “rat sarcoma,” I could imagine a rat with a tumor somewhere in my house; maybe ERK reminds me of my friend Erik, so I could picture him as the last step. It can be done, but it demands imagination. As a result, I find the memory palace a good investment only for very high yield information that I need to summon over and over.

Mneumonics. Poems, acronyms, acrostics, and other types of word play fall into this category. Mneumonics are extremely common in medicine – so much so that they pepper every few pages of my review books, and that there exist entire websites devoted to them. They work because they take things that lack any sort of transparent meaning and package them in ways that resonate with subjects that are familiar in our everyday lives (example: “Some Lovers Try Positions That They Can’t Handle” resonates more than the arbitrary names of the hand bones, Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, and Hamate). Others are just catchy (to recall which nerves innervate the diaphragm, I still say the rhyme, “C3, C4, and C5 keep the diaphragm alive”). For topics where order matters, I also often find verbal mneumonics simpler than coming up with ways to place the items in the memory palace. For example, to remember the order of structures in the femoral triangle region of the thigh – nerve, artery, vein, empty space, and lymphatics – I find “NAVEL” easier to recall than attempting to mentally place those body parts around my house.

The verdict is that this is a fantastic technique that I use frequently in medical school. I will point out one downside, though, which is that speed of retrieval does matter in medicine – so if your mnemonics get too unwieldy, they are less useful. For example, imagine being on rounds, and having your attending ask you a question about the ninth cranial nerve. If you use any of these mneumonics to remember the twelve cranial nerves, and you need to go through them all to get to number nine, your answer will be slow. And that won’t look good. The consequences of slowness during actual patient care, of course, can be more dire than a damaged ego.

Be emotional. For good or bad – we remember things that make us feel. In addition to personal anecdotes, there is much research supporting the idea that emotional experiences are remembered more vividly that less emotional experiences. Brain scans, for example, show that when people store and later recall vivid memories, both the amygdala (a part of the brain involved in emotion) and the hippocampus (a part involved in memory) are at work, and those with better recollection use the emotional parts of the brain more.
When people encode vivid memories, the amygdala and hippocampus interact. Emotional memories are retrieved better than neutral ones. 

Does it work? That we remember better when emotions are involved bodes well for medicine – a career in which we will be caring for human lives and thus often immersed in emotional situations. Already, I have experienced the impact of emotions on memory. I have been more successful in remembering information about illness when a patient was involved than when I was studying from a book. The details stuck because they mattered. I am comforted by the idea that my experiences with patients will be positive not only from a humanistic standpoint of providing compassionate care, but will also aid in my life-long learning to deliver quality care.

The downside is that during the first two years of medical school – when we are supposed to be learning the basics of all of medicine – our patient experiences are limited. During first year I saw patients once a week; during second year, it will be twice a week. The vast majority of my learning is from detached books. Still, we can do things to make our emotional memories work for us; I find that placing information about illness even in the context of a fictional patient is helpful. (I’ve even tried fictionally afflicting myself with diseases I am learning about – I’ve had some success there too, but to a lesser extent.)
Another downside of relying too much on emotional memory is that it can open the door for biases. For example, doctors may be more likely to diagnose a new patient with an illness they have seen recently, in a situation that emotionally stuck in their minds, even when other options they have not recently seen might be just as logical. I hope that awareness of those potential limitations in our thinking can help me work consciously and actively to avoid letting them bias my decision-making.

Repetition. Every psychology text under the sun will tell you that repeating things will help with remembering them. The second exposure to facts is easier than the first, and the third is easier than the second. While I find this extremely true, the one caveat I would point out is that simply repeating another’s words, without having an intuitive grasp of what you are saying, is not the way to make this technique work. Medicine involves a lot of rote memorization, certainly, but it also involves conceptual understanding. Saying “increased afterload leads to decreased stroke volume” over and over, without understanding the physiological steps of how and why, does little for effective memorization. More importantly, it does little for making connections and applying, which is what we really care about in medicine.

The concept map. During first year, our physiology professor drilled this one in our minds. A concept map involves writing ideas in circles and connecting them by arrows. More than one arrow can go to more than one circle, and they can represent relationships like “contributes to” or “is caused by.” It works because it enables you to piece information together in your own ways, seeing how parts of systems work together without skipping steps or making leaps. We remember things better when they make sense. And, just like I said in the repetition section, the more important benefit is that it does wonders for understanding and applying – the ultimate goal in medicine.
This one sounds obvious, but I’ll say it anyway: concept maps are useful only for conceptual understanding. The memorization involved in medicine involves a blend of conceptual understanding and rote memorization. Concept maps have helped me make sense of how the human body acts and reacts, but unfortunately does less for topics like drug names and anatomy.

Be healthy. Our bodies influence our brains. Though not all mechanisms are understood, we remember better when certain things are taken care of better: when we eat well, exercise, and get enough sleep. Unfortunately, I’d guess this is the one we are most likely to overlook in medical school. But all of these tactics are pretty convenient, in that these are things we should be striving to do anyway.

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How much memorization should be required during medical school? That is a question up for debate, with widely mixed opinions. Some who have made it through to the other side argue that the modern system emphasizes too much, for the reality of clinical care is that you will always be looking up information. Critics also point out each of us will go into a medical specialty; so knowing everything about everything is less sensible than choosing a path earlier and focusing our learning on what we will actually be practicing. There’s also the consideration of motivation. A medical student who feels burnt out from the first two years might become a less astute, less caring physician.

Others maintain that it is important to know a lot, because even if you don’t remember everything (and you won’t), that first exposure is critical in developing an understanding of the overall landscape and how different pieces of medicine relate to one another. That is, even if you don’t remember the exact details of what you learned, you will remember that the information exists – so you will know what to look up, and how it’s relevant.

I am not nearly far along enough in my medical training to have a strong leaning one way or another. I imagine things will become clearer when I am caring for patients and can gauge what kinds of information I use on a regular basis, what I use my memory for, and what I tend to look up. There’s also the fact that the two lines of reasoning above are two ends of a spectrum – and the answer may very well lie somewhere in the middle.

When drowning in memorization, some perspective is valuable. In the end, the most challenging parts of medicine are yet to come – and they will not involve problems of memorization. The facts I am committing to memory now will be the building blocks to solve complex patient cases later. I will come across symptoms that will not fit into recognizable molds. My future will involve piecing together clues, weighing relevant and irrelevant information, proposing new ideas that are conceptually viable, and evaluating outcomes. I will have to identify and confront my own biases to try to hone in what is true, rather than what is easy, convenient, or familiar. I will have to critically evaluate my own skillsets and recognize when to ask for help, and from whom to get it. I will have to do all of this within the framework of human interaction, being constantly mindful of patients’ emotions, thoughts, and concerns. I will be treating human beings, not diseases. And that is what I am looking forward to.

In my first year physiology course, our professor gave us weekly quizzes. Each quiz was open book and open notes. Our final exam was a five-page case on a fictional patient, given to us two days in advance, where we could work in groups consulting any and all resources we had. That four-hour exam and the quizzes preceding it were the most academically challenging of anything I took first year. Our professor was preparing us, and I am grateful for the standards he held us to. Because that’s medicine, he told us: “open book, but still hard.”

By Ilana Yurkiewic. Tomado de: http://blogs.scientificamerican.com/unofficial-prognosis/2012/07/26/drinking-from-a-firehose-can-research-into-the-human-mind-help-with-medial-school-memorization/

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