The Science of “Chunking,” Working Memory, and How Pattern Recognition Fuels Creativity | Brain Pickings
June 22, 2013
June 18, 2013
Yesterday I stumbled upon this article in Science magazine. I thought it was very clever how the presence of higher levels of C14 due to the surface nuclear explosions between 1945 and 1963 helped determining that adult neurogenesis takes place in the brain. The area where this rather robust formation of new neurons takes place is the hippocampus. Quote: (…) a subpopulation of neurons renews consistently and continually, whereas another population is nonrenewing. Spalding et al. estimate that one-third of adult hippocampal neurons are turning over. This amounts to 700 new neurons added per day, for an annual turnover rate of 1.75% (or 0.004% of dentate gyrus neurons). This turnover rate was not significantly different between men and women and declined only modestly with age.
Hippocampus! I had just read about the hippocampus in Chapter 5. This is an important brain structure required for the formation of explicit memories, those that we are conscious of. Implicit memories, albeit not conscious, may be powerful and motivated by feelings, beliefs, and behaviors. Explicit memories can be semantic (facts, labels, names etc) and episodic (basically stories- more likely to contain errors, even when we think we remember them well).
The authors of the Science article state: Adult neurogenesis in this region might add a particular functionality not achievable by other types of plasticity. By staying “forever young,” the dentate gyrus could command unique solutions to computational problems only found in the brain region central to learning, memory, and many higher cognitive functions considered essential for humans.
Well, that was cool to read. I went back to Zull’s book to finish the chapter. He talks about the connection between hippocampus and both centers of pleasure (such as basal ganglia) and the amygdala. It adds to the idea of learning framed within emotions and feelings, and how factors such as stress and PTSD can affect memories through hormones such as adrenaline and cortisol. Low levels of stress may enhance long-term memory, while chronic stress may damage the memory centers through the action of cortisol.
The final reflection is about how, at the end of the day, everything is connected. Rote memorization is helped by feelings or other associated memories, and having the memory of concrete facts or dates may help remember a story easier.
June 13, 2013
Apologies if you saw a draft published- I was sitting on a very long graduation ceremony and was making notes on my smartphone, and then clicked on an icon I thought was “save” but it was “publish.” Some scrambling ensued. I am writing now from my laptop.
As I advance deeper into the book, I feel myself more and more engaged. It reads almost like a detective novel, slowly and steadily unraveling the mechanics of the brain, easily combining biological descriptions of anatomical structures with personal stories of students and colleagues, as well as reflections about teaching and learning.
Chapter 5, titled A feeling of this business, starts with a personal story about a biology professor who insisted in incorporating math into his biology classes, something very logical that did not earn him popularity among students. That hit home-much has been said how the lack of math and physics in biology education has damaged the future experts of the discipline. But what really hit home was a comment of this professor: that when asked by a student how did he know what to do to solve an equation, he couldn’t answer. “I cannot really explain…I just feel it.” And this is something I often feel: a sense of what is the right way of doing something. Often it becomes almost artistic- a sense of balance or something aesthetically pleasing. When designing an experiment, for instance, positive and negative controls line up with the samples in a matrix that is not only scientifically sound, but also complete in the artistic sense. There are no overhangs or holes.
Zull goes on explaining how emotions and feelings, although similarly sounding, are not the same. Basically, emotions become feelings when we become conscious of them. He cites William James’ example of meeting a bear: emotions transmitted by the amygdala make you run like hell, but it is only later when we feel the fear. Which makes perfect sense. The few times in my life when I have been in direct danger I acted coolly, and fear came only later.
After this there is a section dedicated to the hypothalamus- the center of homeostasis in our brain, but also a center of control, which, upon receiving signals from the limbic system (fear, particularly) is able to release hormones and other cellular mediators to act in our body. Typical example is the adrenalin rush, the classic flight or fight response of the sympathetic nervous system.
What I really like is how Zull’s book jumps from the descriptions of brain structures back to teaching scenarios. How do we know if a certain fact is true? In a way, it is a feeling– and if that feeling if certainty is challenged, we feel fear, so we try to prove we are right- and the more we do it the more confident we feel. And so we learn.
I hope you realize that I am reading this book slowly, because I am writing about it, so I need to be able to paraphrase and summarize it. Along the way, associations pop up, ideas blossom, and I get distracted in the good way, but then find my way back to the book. It is a great intellectual experience, which I am able to do because I am on a week vacation away from home. I will stop now, as this requires some processing before moving on.
As for the Gettysburg address memorization project, I just hit sentence #6. “But in a larger sense, we cannot dedicate, we cannot consecrate, we cannot hallow this ground.” I am absolutely blown away by the usage of words in this speech. It plows forward, inexorably, with s sense of purpose and no distractions. Amazing writing.
Be back tomorrow.
June 12, 2013
I took a day break after finishing chapter 3 of the Changing the Brain book, with the idea of a balance between the different parts of the brain that need to be stimulated for effective learning. This morning, as I started reading chapter 4, I had to smile as it delved into several topics I have been reading about recently. One had to do with the primitive survival mechanisms of the brain based on fear and pleasure. The example for the second was sugar, of which I learned recently a lot from the book Salt Sugar Fat by Michael Moss. I wholeheartedly recommend this book to anybody interested in healthy eating and the role of big food corporations in contributing to the epidemic of obesity. The other topic was about extrinsic versus intrinsic motivation, which was much discussed as part of the Gamification MOOC I took some months ago. My positive view of the MOOCs is very much due to the excellent experience of taking that course.
But I am digressing. Zull winds his way in this chapter from the structures of the brain “in charge” of survival mechanisms, such as the limbic system for pleasure/fear, and the neocortex for more advanced mechanisms involving understanding and control. After describing the structures of the limbic system, particularly the amygdala, the site of “fear,” and the ‘septum,” of pleasure, he discusses how emotions can affect learning (positively or negatively). Note: Zull simplifies (on purpose) the description of brain areas and their associated functions, and I am not focusing too much on it either, so for a better description of these structures it is better to use a more detailed source. It all connects with the feeling of being in control of the learning process, which is more pronounced when the motivation is intrinsic (true interest, emotional connection) than extrinsic (rewards such as a high GPA). Movement (even anticipated or imaginary) bring pleasure to the learning process, leading to the idea that active learning is more engaging than passive learning. The chapter closes where it started, the idea that learning is a continuous process modulated by wants, needs, and emotions. and therefore it is our trade and art…paraphrasing de Montaigne, my trade and my art is living.
June 10, 2013
I seldom read only one book at a time, except when it is one of those books that I cannot put down (such as the Harry Potter or the Song of ice and Fire series). So while I am reading The Art of Changing the Brain in its paper form, I have also The End of Big on my tablet. In a way, the two books are on their appropriate platforms: the former reads best while taking notes on the side (I have not yet found a digital way to take notes that is as effective for me as the actual act of writing), and the latter has so many interesting links that having it on the tablet lets me immediately check them out.
I will eventually write my impressions on The End of Big, as it is a powerful book, covering many areas and very thought-provoking. But today I will write about a mental collision I had last night, just after I finished reading Chapter 3 of the Brain book. If you read my previous posting, this chapter is about the right balance for stimulation of both the front and the back of the barin (providing the knowledge and also acting on it). The end of that chapter, which I did not finish in the posting, is about the factors that affect this balance in a negative way, be it the amount of information perceived to be necessary (and crammed into courses), or the push toward being an innovative teaching (so most time is spent in the active testing part). I completely agree with that, as the whole idea of reading this book and in general books about learning theories was because I feel that often we educators just implement things because they are popular, not because we know How and why to use them…
So I felt validated and cozy, and before going to sleep read a bit of the End of Big book. And stumbled on the following: “My hobby for the past decade has been memorizing comments.” The chapter is dedicated how our memory has changed (for the worse) because of the existence of Google. Citing Nick Carr’s provocative question: Is Google making us stupid?,” the autor goes on saying how much he cherishes his memorized poems, and without going too deep, how he worries about the effect of radical connectivity on our knowledge.
So I had to sit back and think for a bit. I had to memorize many poems when in high school (in Europe eons ago), and I can still recite most of them. When teaching anatomy and physiology, I require my students to memorize the normal values of blood pH, pCO2, and bicarbonate values. But for the past 2 decades, I do not think I had ever memorized or required to memorize anything, as it seemed a waste of brain power.
So I decided to do an experiment: I am very fond of Lincoln’s Gettysburg address, so I decided to memorize it. English not being my first language, it will probably take longer. I have so far managed to sentences- but they are complex sentences. “..a new nation conceived in liberty and dedicated to the proposition that all men are created equal.” I had to think of each work deeply, why exactly was this word used and not another synonym?
And as I went through each word and the exercise of putting those words in order, I had this little light bulb in my head turning on. There may be some value to memorizing after all. Especially if memorization involves a powerful intellectual processing exercise.
So very cool- to appreciate memorization via en internet guru.
June 9, 2013
Chapter 3. was the first that made me reflect critically on my teaching. The main message of the chapter is how effective teaching requires a balance between activities addressing each step of the learning cycle. The chapter starts with a case and a generic description of the so-called “passive students,” those who only memorize, never ask questions, and struggle to put things in their own words.
When information in the brain is changed to understanding, several processes tak place:
- Transformation from past to future: the information of the past becomes the basis of actions and plans for the future.
- Transformation of the source of knowledge from outside ourselves to inside ourselves: we change from receivers to producers, able to create new knowledge.
- Transformation of power: we take responsibility for our own further learning.
Going back to the previous chapter and the structures of the cortex associated to the different phases of the learning cycle, one can say that the receiving and remembering part of the brain is in the back of the cerebrum, and the front is in charge of the generation of ideas and actions. In more detail, these are the functions associated with the cortexes:
Back integrative cortex: memory of stories and places, understanding language, flashbacks, emotions related to experiences, long-term memory.
Front integrative cortex: Choice, decisions to act, inhibition, emotions associated with actions, responsibility, mental energy, consequence, predicting, creating.
So the idea is to stimulate and connect both parts- and they are indeed connected, through nerve bundles called fasciculi.
Studies have already tried the combination of the traditional didactic approach and the discovery approach. They seem to corroborate that only a combination of both will provide both understanding both quick and deep.
The part that made me reflect on my teaching was the following paragraph: “Balance is a matter of justice. If we do not teach to both the back and the frotn cortex, it is unjust for students.Keeping a just balance is our duty.“
Probably most educators struggle with this dilemma: how can we deliver information to provide both the content and the opportunity to practice and apply that information? Zull talks about what are the pressures toward imbalance, and some ideas to work toward it. From my own experience, I know how easy it is to go from one extreme to the other, with variable success. So I am looking forward the rest of the chapter, which I will finish for the next posting.
Until next time!
June 6, 2013
I am afraid I may get off topic with this chapter. It is just too much fun reading it, and it brings associations and ideas. For instance, one of the quotes starting chapter 2, is from none other that James Watson: “It was so pretty it had to be true,” referring to the double helix of DNA. That brought to memory the following endearing video:
For Zull, becoming the director of a teaching center meant he could dedicate time to learn about learning, as he had never had the time before (the norm for the publish or perish research academics). He read about the sequence of experience, reflection, abstraction, and active testing; necessary for deep learning. His initial skepticism changed one spring afternoon, when everything came together (a bit like for Watson in the video): the structure of the brain and the functions associated to learning. Eureka!
The next few pages relate to the structure of the brain and how the nervous system works. It is nicely done, summarizing in lay language the regions of the cerebral cortex, and what they do: sensory, integration/association, and motor areas.
Back to the giants of the science of learning (Dewey, Piaget, Kolb) and the sequence of learning (see below- please note that the wording changes slightly between the internet figure & the current book), Zull talks about the importance of experiential learning, meaning knowledge comes from experience, but it requires the other components.
For Zull, the eureka moment came from juxtaposing the areas of the brain with the phases of the cycle:
Sensory/postsensory cortex=> Concrete experience
Temporal/integrative cortex=> Reflective observation
Frontal/integrative cortex=> Abstract hypotheses
Premotor/motor cortex=> Active testing
The next thing is to consider is: what is the difference of teaching and learning? And based on this model, because all starts with experience, all teaching does result in learning…but it may not be what the teacher intended for the student to learn.
The rest of the chapter expands on the hypothesis that we can map different aspects of the learning process to specific areas and functions of the brain, and illustrates it with examples (for example, seeing/hearing a new word, mapping it to earlier memories, analyzing it, and then testing if the hypothesis is correct). Brain imaging studies have shown that this kind of sequential activation of different regions do occur, although Zull clarifies that the cycle sometimes may go back and forth, and often several cycles may be occurring simultaneously.
The final reflection of the chapter is: how can be use this knowledge for teaching? How can be design activities that encourage reflection? How can we make students develop abstract ideas? In what ways can students demonstrate their ideas and test their validity?