kitchen table math, the sequel: working memory
Showing posts with label working memory. Show all posts
Showing posts with label working memory. Show all posts

Tuesday, July 2, 2013

Why students need to memorize, Common Core edition

"...anything that occupies your working memory reduces your ability to think."
- Daniel Kahneman | Thinking Fast and Slow
The only way to clear space in working memory is to store knowledge in long-term memory.

AND SEE:
Why students have to memorize things
#whystudentsneedtomemorize

Friday, November 30, 2012

two years is two years

more from Barry's article on the Common Core:
This approach not only complicates the simplest of math problems; it also leads to delays. Under the Common Core Standards, students will not learn traditional methods of adding and subtracting double and triple digit numbers until fourth grade. (Currently, most schools teach these skills two years earlier.) The standard method for two and three digit multiplication is delayed until fifth grade; the standard method for long division until sixth. In the meantime, the students learn alternative strategies that are far less efficient, but that presumably help them "understand" the conceptual underpinnings.
Once again, knowledge stored in memory is entirely different from knowledge stored on Google.

Biological memory is a biological process that requires a period of time during which new memories are consolidated:
Memory consolidation refers to the idea that neural processes transpiring after the initial registration of information contribute to the permanent storage of memory.
Memory consolidation, retrograde amnesia and the hippocampal complex
Lynn Nadel* and Morris Moscovitcht Cognitive Neuroscience
I don't know how much time the brain requires to consolidate memories, but I recall John Medina suggesting that the figure may be as long as 10 years. (That would jibe nicely with the 10-year rule for development of expertise, wouldn't it?)

The "consolidation lag" between first learning a new skill and really knowing that skill explains why "just-in-time" learning is so crazy. There is no such thing as just-in-time learning. The brain doesn't work that way. No matter how smart you are, if you are 17 and you don't know how to do long division, you can't just have your professor show you how and then start doing it. Knowledge has to be consolidated before you can use it well, and consolidation takes time.

Here is James Milgram on his experience teaching Stanford students who had not been taught long division:
What happens when you take long division out of the curriculum? Unfortunately, from personal and recent experience at Stanford, I can tell you exactly what happens. What I'm referring to here is the experience of my students in a differential equations class in the fall of 1998. The students in that course were the last students at Stanford taught using the Harvard calculus. And I had a very difficult time teaching them the usual content of the differential equations course because they could not handle basic polynomial manipulations. Consequently, it was impossible for us to get to the depth needed in both the subjects of Laplace transforms and eigenvalue methods required and expected by the engineering school.

But what made things worse was that the students knew full well what had happened to them and why, and in a sense they were desperate. They were off schedule in 4th and 3rd years, taking differential equations because they were having severe difficulties in their engineering courses. It was a disaster. Moreover, it was very difficult for them to fill in the gaps in their knowledge. It seems to take a considerable amount of time for the requisite skills to develop. [emphasis added]
Transcript of R. James Milgram
1999 Conference on Standards-Based K-12 Education
There is no just-in-time learning, and you can't catch-up.

For the sake of argument, say it takes two years to consolidate the skill of adding and subtracting double-digit numbers. (I'm guessing it takes more than two, but I don't know.) If a child learns to add and subtract double-digit numbers in second grade, he or she will be proficient in fourth grade.

Delay teaching the algorithms until fourth grade and now you have a cohort of students who won't be proficient in addition and subtraction until 6th grade.

That's the way it works. Two years is two years.

and see:
Eide Neurolearning explains elaborative rehearsal 

Tuesday, July 3, 2012

brain memory is different

Larry Summers, economist:
Suppose the educational system is drastically altered to reflect the structure of society and what we now understand about how people learn.
Richard Clark, Paul Kirschner, & John Swellers, psychologists and education researchers:
Our understanding of the role of long-term memory in human cognition cognition has altered dramatically over the last few decades. It is no longer seen as a passive repository of discrete, isolated fragments of information that permit us to repeat what we have learned. Nor is it seen as having only peripheral influence on complex cognitive processes such as critical thinking and problem solving. Rather, long-term memory is now viewed as the central, dominant structure of human cognition. Everything we see, hear, and think about is dependent on and influenced by our long-termmemory.
Putting Students on the Path to Learning
Richard E. Clark, Paul A. Kirschner, and John Sweller
American Educator | Spring 2012
Here's a thought.

Before Larry Summers writes a NY Times op ed invoking "what we now understand about how people learn," he should do a little nosing around and find out what we now understand about how people learn.

Hint: what we now understand about how people learn turns out NOT to be that in a world where the entire Library of Congress will soon be accessible on a mobile device with search procedures that are vastly better than any card catalog, factual mastery will become less and less important.

Long-term memory is a biological entity with cognitive functions.

Internet archives are storage facilities.

Those two things are not the same.

P.S.: A Commenter reminded me of the Clark/Kirschner/Sweller article the other day, when I was trying to recall where I'd read the passage about long-term memory having a cognitive and biological function that Google does not. Unfortunately, I can't remember who it was, but thank you!

AND SEE:
Larry Summers has a really bad idea
Look it up

Monday, January 23, 2012

Why students have to memorize things

re: Larry Summers' claim that "in a world where the entire Library of Congress will soon be accessible on a mobile device..., factual mastery will become less and less important":

Larry Summers is wrong.

Factual mastery has not and will not become less important, for the simple reason that it is not possible to think about something stored on Google.

While you are thinking about something, that something has to be lodged inside working memory, not Google.

Biology does not work the way Larry Summers thinks it works.

Working memory

If I ask you to multiply 36 by 3 inside your head, working memory is what you use to do it.

Working memory (WM) does three things:
  1. Holds the problem -- "multiply 36 by 3" -- in consciousness 
  2. Retrieves the relevant knowledge from long-term memory (the times tables, in this case)
  3. Performs the calculation
Boiling it down, working memory is:
  1. a form of storage
  2. a search engine 
  3. a "computer" or thinker
"Critical thinking" is accomplished by working memory.

3 to 5

The fact that we can think only about things stored inside working memory leads directly to the need for "factual mastery."

Factual mastery—knowledge stored inside long-term memory—is essential because although long-term memory is vast, working memory is tiny:
...cognitive tasks can be completed only with sufficient ability to hold information as it is processed. The ability to repeat information [you have just heard or read] depends on task [difficulty]... but can be distinguished from a more constant, underlying mechanism: a central memory store limited to 3 to 5 meaningful items in young adults.

The Magical Mystery Four: How Is Working Memory Capacity Limited, and Why? by Nelson Cowan
Working memory can hold three to five items at once. That's it. That's the limit.

Three to five.

I hit this limit all the time trying to write about new topics. The basal ganglia, for instance. For well over a year, I have been endlessly working and re-working a project on the basal ganglia, a subject I knew essentially nothing about going in. Where the basal ganglia were concerned, my long-term memory was a blank slate.

The upshot: I was not able to write about the basal ganglia until I actually learned about the basal ganglia: learned as in committed the material to memory. It didn't matter how many times I looked up basal ganglia on the internet. I looked up the basal ganglia on the internet a lot, as a matter of fact; then I forgot whatever it was I had looked up while I was looking up something else to do with the basal ganglia, after which I'd have to go back and re-look up the first thing all over again.

Try it if you don't believe me.

Here are some terms related to the basal ganglia:

Dorsal striatum
Ventral striatum
Putamen
Nucleus accumbens
Ventral tegmental area
Orbital frontal cortex
Dopamine
Two pathways
OCD
Addiction
Habit
Impulsive
Compulsive
Intuition
Probabilistic learning
Associative learning
Statistical learning
Serotonin
Orbitofrontal cortex
Cortico-striatal circuit

Now supposing I handed you a laptop and asked you to look up each term on Wikipedia, then write a coherent, reasoned 5-paragraph essay on the basal ganglia: what it is and what it does. Just a quick summary organized into 5 coherent paragraphs.

You couldn't do it.

You couldn't do it because every time you wrote about the ventral striatum, the dorsal striatum, and the orbitofrontal cortex, you would forget the VTA and the putamen—and you would forget the VTA and the putamen because your working memory will hold only 3 to 5 things at once. Something has to go.

That's what happened to me when I took the SAT with a calculator I didn't know how to use. Each time I swapped the steps for using the calculator into working memory, my brain swapped the information for the problem I was doing back out of working memory. Then, when I tried to cram the information for the problem back into working memory, the calculator steps got squeezed out again.

I could remember the problem, or I could remember the calculator, but I couldn't remember both at the same time. Too much information, literally.

My calculator fiasco illustrates the reason you need to practice until you learn content and skills to the point of 'automaticity.' (Automaticity is another basal ganglia term, by the way. The basal ganglia are the part of the brain that underpins automaticity.) Once you've learned something so well you don't have to think about it, you free up space in working memory to hold other things.

Thus if you know the times tables "by heart," you don't need to pull "3x6=18" into working memory. Working memory can locate "3x6=18" inside long-term memory and use it without displacing "36x3."

Knowledge stored inside the brain is different from knowledge stored outside the brain

Experts always possess factual mastery of their fields. Always.

The reason experts always possess factual mastery of their fields is that knowledge stored in long-term memory is different from knowledge stored on Google.

Knowledge stored in long-term memory is (or becomes) biologically connected, or "chunked." Thus to an expert on the basal ganglia, ten facts about the basal ganglia are just one or two big facts about the basal ganglia.

Chunking is the magic, because working memory doesn't care about chunk size. Working memory can hold 3 to 5 small and simple items or 3 to 5 large and complex items. Either will do. Chunking gets around the limits on working memory.

Dan Willingham's demonstration of working memory

For a demonstration of the chunking principle, read the list below, then look away and try to remember what you've read:

CN
NFB
ICB
SCI
ANC
AA

How many letters did you recall?

To find out how many letters you would have recalled via prior chunking inside long-term memory, see Daniel Willingham's explanation in "How Knowledge Helps" (American Educator | Spring 2006).

(The answer is all of them.)

You can't Google knowledge chunks

Knowledge chunks can be created only inside the brain, via learning. You can't Google someone else's complex knowledge chunks and swap them into your own working memory. It doesn't work that way. Your own brain has to do the work of chunking, and your brain does that work through the process of learning, bit by bit and step by step.

Which means that the process of storing content in long-term memory is not a simple matter of "memorizing facts" so you can "regurgitate" them later.

Over time, memorization creates the complex knowledge chunks that allow knowledgeable people to engage in complex thought.

Experts think better than novices because experts have factual mastery


To a gratifying degree, I can now think about nearly all 19 items on the basal ganglia list at the same time. I'm still struggling with "putamen" and "ventral tegmental area," but the other 17 are stored in memory: my memory, not Google's. So, for me, those 17 items are no longer 17 separate items, but closer to 2 or 3. When I think about 1 item on the list, I'm thinking about the others.

I reached this point by committing these terms and concepts to memory. As the terms entered my long-term memory, they became biologically connected and chunked. Now that I can think about them at the same time, which means I can write about them, too.

What makes experts expert, to a large degree, is factual mastery of their fields. Factual mastery allows experts to think deeply and well because the content they are thinking about has been biologically connected and chunked inside their brains, and there is no obvious limit to the amount of chunked content working memory can manage so long as knowledge has been chunked into no more than 3 to 5 separate entities.

Factual mastery is required for complex thought.

Which brings me back to Larry Summers.

If our schools are going to ask students to 'think' about material they haven't learned, students are going to be thinking about 3 to 5 small, not-well-elaborated items at a time. Period. Their thinking will be superficial, and the conclusions they reach will be superficial, too.

Which is exactly what we see in Larry Summers' op-ed about education, a field in which he is neither expert nor learned.

AND SEE: 
Superior Memory of Experts and Long-Term Working Memory (LTWM)
Extremely fast learning & extended working memory
The Number and Quality of Representations in Working Memory by Weiwei Zhang and Steven J. Luck
How Knowledge Helps by Daniel T. Willingham American Educator Spring 2006

#whystudentsneedtomemorize

Larry Summers has a really bad idea

In today's Times, Larry Summers weighs in on the question of what college students ought to learn in college.

Larry's answer: not too much, because the entire Library of Congress will soon be accessible on a mobile device with search procedures that are vastly better than any card catalog!

Larry bases his novel and highly original thesis (to wit: "factual mastery will become less and less important") on "what we now understand about how people learn."

(Does Harvard have node chairs, I wonder? Sounds like no.)

OK, I'm going to go look up calculus on the internet. I've always been interested in calculus, so now that I've received a mobile device for Christmas, I'm going to look it up. Then I'm going to collaborate with some friends who also looked up calculus on the internet to figure out what to do about the 21st century global world meltdown.

I'm going to do this because I've noticed that economists use calculus in their collaborative group papers.

[pause]

There is a reason why students must commit content to memory as opposed to looking it up on a mobile device with search procedures that are vastly better than any card catalog.

That reason has to do with working memory.

More anon.

What You (Really) Need to Know by Lawrence A. Summers

update: Why students have to memorize things
and see: Extremely fast learning & extended working memory

AND SEE:
The founder, chair, and CEO of Netflix has a really bad idea
Larry Summers has a really bad idea
Wash U professor on Reed Hastings' really bad idea
Barry Eichengreen has a really bad idea
President Obama has a really bad idea

David Brooks has a really bad idea

David Brooks has a really bad idea, part 2
David Brooks has a really good idea

The Daily has a really bad idea

Friday, November 11, 2011

anonymous on lefties taking the SAT

Good advice:
Lefties should be particularly vigilant about the chairs/desks. I've heard stories about them having to take long tests on right-handed flip-up deskettes; a true nightmare. I know the registration forms for my grad comps asked lefties to identify themselves, because almost all of the seats in the auditorium had right-hand deskettes. They brought in as many extra lefty ones as they needed. Is there a similar question on SAT registrations?
I have got to find time to write a quick post on working memory.

I believe that the "transmission mechanism" from right-hand desks for left-hand test-takers to reduced performance is working memory blowout.

And see: death by calculator. Death by calculator is a case of working memory blowout.

(The real-world term for working memory blowout problems is cognitive load theory.)

Sunday, October 23, 2011

Steve H on SAT math and math prep

from the comments:
SAT math tries to trick students. You could say that the tricks relate directly to whether or not they really understand math. However, when you add in the time constraints, it really relates to preparation. Is preparation the same as mastery? Yes. Mastery of the test. Is this equivalent to mastery of math or whether you will do well in college math? Not necessarily. There are better ways of determining that than with the limited material included on the SAT. Why not just require students to take the Achievement Test? Look at the AP Calculus grade.

What is it about SAT-Math that is so important? They are trying to test something other than just math knowledge. They think that these tricky questions reflect on how well you think on your feet, but what it really does is test preparation and whether you have seen these questions before. The questions don't reflect on whether you have a wide body of knowledge and skills in math.

They create problems where you have to "see" the shortcut. You get problems with hidden 3-4-5 triangles. Add a time constraint and then what do you call those problems? It's not just about math knowledge and skills. The problem has to do with trying to determine the difference between aptitude and preparation. The tricks may have some basis in meaningful math, but that's not what they are trying to test.

It reminds me of questions companies like to ask at job interviews, like "Why is a manhole cover round", and "How many golf courses are there in the US.?" Preparation can make you look like you have a great aptitude. Preparation is directly related to math knowledge, and that is important, but identifying aptitude is an arms race for something like the SAT. That's causing the tricky problems, not any desire to test a breadth and depth of math knowledge.

In Dick Feynman's books, he talks about how he spent a lot of time in high school learning about all sorts of trick, lateral thinking problems. He would challenge people to ask him questions. There is nothing like preparation to make you look like a genius, although he really didn't need help with that. It really annoyed some of his colleagues.

My son will get to calculus in his junior year and he always gets A's. He still has to prepare for SAT-Math. He can't let others, with specific SAT-Math preparation, seem like they have a better aptitude than him.
and:
They try to trick students in most questions....What bothers me the most are the shortcut problems where using standard math techniques cause you to take too much time. This is supposed to identify aptitude, but it really tests preparation for the test.

There are also the problems where using a brute force or direct counting technique works better than any applied math technique. In some cases, there is no math to apply. One question on a sample PSAT test asked for the number of positive integers less than 1000 which don't have a '7' as one of the digits. (notice - "don't have" and positive integer) This simply checks how well you work under time pressure. Nobody expects you to apply any fancy math to this problem. One of the answers was the "have" solution. This tests preparation and practice, not aptitude or math ability. There may be a correlation between the test and aptitude or math ability, but not to the resolution colleges use it to select students. At the top levels, it correlates to preparation. That's not necessarily a bad thing, but there are better ways of figuring that out.

Friday, July 22, 2011

working memory in children

[T]he findings from this study indicate that the three main components of the Baddeley and Hitch (1974) model of working memory are in place by 6 years of age. The capacity of each component increases linearly from age 4 to early adolescence.


The Structure of Working Memory From 4 to 15 Years of Age
Susan E. Gathercole
University of Durham Susan J. Pickering, Benjamin Ambridge,
and Hannah Wearing
University of Bristol
Developmental Psychology 2004, Vol. 40, No. 2, 177–190
Children have lower working memory than adults, and lower working memory has ramifications for language learning and some cases of problem solving.

Thursday, July 21, 2011

when smart is dumb

Directions:

Make each statement true by moving just one matchstick.


In Choke, Sian Bielock discusses a study in which more than 90% of adults with normal working memory correctly answered the first problem. Roughly the same number of people with damaged working memories also got it right.

Only 43% of normal adults got the answer to the second problem, while 82% of patients with damage to the prefrontal cortex figured it out.

I believe high-functioning people with autism (or a healthy loading of autism genes) will also have a high rate of success on problem number 2, but that's just me.

Better without (lateral) frontal cortex? Insight problems solved by frontal patients
Carlo Reverberi,1,2 Alessio Toraldo,3 Serena D’Agostini4 and Miran Skrap4
Brain (2005), 128, 2882–2890

Choke

Wednesday, July 20, 2011

working memory

Just came across this textbook chapter on working memory and thought I'd share it. Don't know who wrote it.

Bielock writes that "working-memory differences across people account for between 50 percent to 70 percent of individual differences in abstract reasoning ability or fluid intelligence."

Working memory also makes you dumber in some situations.

I'll get to that later.

Choke: What the Secrets of the Brain Reveal About Getting It Right When You Have To

second language learning - the "less is more" hypothesis

I'm reading Choke by Sian Beilock, a terrific book. Mostly it's about why and how people choke under pressure, but I've been surprised at the number of ancillary topics that turn out to be related to choking -- including foreign language learning by grown-ups.

Beilock says that the reason children learn language better than adults is that children have less working memory (pdf file). Less is more.

She has fascinating things to say about math and problem solving, too.
Statement of Research Interests (pdf file)
Alan W. Kersten
This research has been testing one hypothesis for why adults have so much difficulty successfully acquiring a second language, namely the “Less is More” hypothesis of Elissa Newport (1990). According to this hypothesis, the reduced working memory capacity of children relative to adults actually results in better language learningby forcing children to focus on small chunks of language. Adults, on the other hand, can remember larger chunks of language, allowing them to memorize useful expressions in a foreign language (e.g., “Where is the bathroom?”), but making it difficult for them to extract the lower-level meaning elements from which those expressions are constructed. Adults are thus limited to the set of phrases that they have acquired, and are unable to recombine the lower level elements from which those phrases are constructed to express novel meanings. If this hypothesis is correct, one may predict that adults will learn a language better if they are forced to focus on small chunks of language rather than being allowed to learn entire phrases. We have tested this prediction using a miniature artificial language learning paradigm (see Kersten & Earles, 2001). One group of adults was presented immediately with complete “sentences” from this language, whereas a second group was presented initially only with individual words from the language. This second group was subsequently presented with incrementally longer chunks of language until ultimately they were hearing the same sentences that the other group heard all along. The group that was initially forced to focus on small chunks of language showed better ultimate learning of the word meanings and morphology of that language, consistent with the “Less is More” hypothesis. We are currently investigating whether starting small benefits the acquisition of a natural language with more complex grammar, namely French (Chin & Kersten, in press).

update: Less Is Less in Language Acquisition

Choke: What the Secrets of the Brain Reveal About Getting It Right When You Have To

Tuesday, July 12, 2011

Practice Makes Perfect (But only Briefly)

Sustained practice makes the kind of perfect I'm looking for.

More inspiration from Daniel Willingham:

When we refer to "practice," it is important to be clear that it differs from play (which is done purely for one's own pleasure), performance (which is done for the pleasure of others), and work (which is done for compensation). Practice is done for the sake of improvement. Practice, therefore, requires concentration and requires feedback about whether or not progress is being made. Plainly put, practice is not easy. It requires a student's time and effort, and it is, therefore, worth considering when it is appropriate.


(cross-posted on Perfect Score Project)

Sunday, March 6, 2011

uh-oh

"when A.P. testing began in 1956, memorization was not yet a dirty word"

Rethinking Advanced Placement
By CHRISTOPHER DREW
Published: January 7, 2011
In theory, the new A.P. courses are going to replace "memorization" with "critical thinking."

In reality, critical thinking depends on memorization: you can't think critically without something to think about, and that something has to be stored in long-term memory. If you're going to think critically, you have to know (i.e. remember) what you're thinking about.

What happens when you try to think critically about a subject without memorizing its terms and concepts first?

What happens is that you can think about 4 items at most. That is the number of new, discrete elements you can hold in conscious, "working memory"* at one time. Four. And four may be pushing it.

Of course, when it comes to critical thinking, 4 is a tiny number. Experts think critically about far more elements at one time; being able to think about a vast amount of complex material is pretty much the definition of an expert, as a matter of fact:
The sine qua non of skilled cognitive performance is the ability to access large amounts of domain specific information [i.e. knowledge]. For example, it is estimated that chess masters have access to as many as 100,000 familiar configurations of chess pieces (Chase & Simon, 1973). As another example, in order to make sense of what he or she is reading, a reader must have access to information gained from previously read text. This is particularly true when reading complex technical material filled with jargon.
summary of Ericsson, K. A., & Kintsch, W. (1995). Long-term working memory. Psychological Review, 102, 211-245.
David Zach Hambrick, 1998, gt8781a@prism.gatech.edu

basal ganglia lollapalooza

Here's an example from my own life.

As a nonfiction writer, I'm essentially a permanent student: I am constantly trying to write interesting articles and books (mostly books) about material that may be brand-new to me. My current project involves the basal ganglia, which I knew nothing about going in. The vocabulary alone is overwhelming: nucleus accumbens, orbitofrontal circuit, putamen, striatum --- and that's just for starters.

So here's the question. How exactly am I to (a) understand and (b) think critically about a passage that contains these four terms if I haven't memorized what these terms mean and how they are related to each other first?

The answer is: I can't.

If I don't memorize vocabulary, I have to look up the definitions and then try to hold the definitions in mind while also reading and trying to think about what I'm reading.

It can't be done, and the reason I know it can't be done is that I've spent a lot of time trying to do it. I always make the same mistake with each new project I tackle. Somehow I think I can just look things up (Google!) and remember them while I read a complex study or article.

But I can't. No one can. Looking up four new words and remembering four new meanings maxes out working memory. There's no capacity left to read and understand a text using those four new words and four new meanings, let alone think.

I don't know why this is. Logically speaking, shouldn't it take just as much working memory to hold 4 memorized terms in mind as it does to hold 4 non-memorized terms in mind?

The answer is no: knowledge - content stored in long-term memory - extends working memory.

When you know a lot about a subject - when you have a great deal of knowledge stored in long-term memory - you can think about more than just 4 things at once.


blackboards vs PowerPoints

* Working memory is essentially consciousness: it's what you're thinking about and/or remembering right now. When you hold a phone number in memory while dialing it, you're using working memory.

Monday, June 21, 2010

talk and chalk

from Have Technology and Multitasking Rewired How Students Learn? by Dan Willingham
When you encounter a new technology, try to think in abstract terms about what the technology permits that was not possible in the past. It’s also worth considering what, if anything, the technology prevents or makes inconvenient. For example, compared with a chalkboard, an overhead projector allows a teacher to (1) prepare materials in advance, (2) present a lot of information simultaneously, and (3) present photocopied diagrams or figures. These are clear advantages. However, there are also disadvantages. For instance, James Stigler and James Hiebert noted that American teachers mostly use overhead projectors when teaching mathematics, but Japanese teachers use chalkboards.33 Why? Because Japanese teachers prefer to maintain a running history of the lesson. They don’t erase a problem or an explanation after putting it on the board. It remains, and the teacher will likely refer to it later in the lesson, to refresh students’ memories or contrast it with a new concept. That’s inconvenient at best with an overhead projector.

33 James W. Stigler and James Hiebert, The Teaching Gap (New York: Free Press, 1999).

Having managed to follow most of Wu's lectures, I am a huge fan of this method - and a huge non-fan of the PowerPoint now-you-see-it, now-you-don't approach to teaching.

limits of working memory
working memory posts

Saturday, August 8, 2009

writing as a phonetic system

Without some context, you might be puzzled (or misinterpret) what exactly Bloomfield's quote means in the passage cited by Catherine...

The question raised is: Can a marking that conveys a general idea be called writing, or must all writing represent specific units of speech?

To this question, the great linguist Leonard Bloomfield apparently gives his answer when he states, "Writing is merely a device for recording speech."

Bloomfield was addressing several questions of his day. Before Bloomberg, linguistics was sort of like a slightly more holistic version of philology, which might be found as a subset of some philosophy or history department. Certainly that was the sort of linguistics I perceived the field to be before I got interested passionately obsessed with it -- dry, pedantic stuff. Today, linguists are slightly more confident about some of the questions today -- thanks to cognitive science, psycholinguistics, documentation of creoles, cross-cultural studies, study of child language acquisition, the acoustics of phonetics, modern evolutionary synthesis, game theory, and 100 other disciplines that emerged in the 20th century. As an aside, I will say that I think true potential of linguistics is still in its infancy, despite the advances of this century. We still don't really know a whole lot about language -- in both its social and biological aspects.

Anyway, Bloomfield was probably commenting on the idea of an ideographic writing system, or even an ideographic language -- a communication system that doesn't ultimately have sound as its foundations. For those in the dark about the meaning of "ideographic" -- there's a popular conception of the Chinese writing system as an organised system of pictographs, with each character standing for an object or an idea, and the characters interacting with each other as though they were abstract symbols, functions and variables performing operations on each other. For example, when a Sinophone expresses "I love forest(s)" in Chinese writing, the ideographic viewpoint would analyse the writing as a graphically-symbolic representation of the ideas contained in such a statement, as though the written statement was an abstract depiction of the first person hugging several trees. (At least I think the character's origin is that of hugging, based on the old ancient seal script way of writing the character 爱 -- ai, or to love. I'm probably very wrong though.)

But of course, the ideographic viewpoint is all wrong. There's a fairly good essay on why exactly the ideographic viewpoint is wrong in an article called "The Ideographic Myth". Victor Mair -- a linguist, sinologist, a professor at the University of Pennsylvania -- has also blogged a few posts about it on Language Log. The basic summary of the arguments is that the Chinese writing system is not actually pictorial, in as much as we do not mean an ox's head every time we write the letter A, which has its origins in the Proto-Canaanite symbol Aleph. (I do not dispute however, that knowing such origins make characters more fun or easier to learn.) On top of that, only a minority of characters in the Chinese writing system have pictorial origins -- frequently, other characters, representing semantically-unrelated meanings, are borrowed and then combined with a few other radicals to form a new character to represent some word. Why? The character that was borrowed simply carried the same (or even just similar) sound. One complication that often makes this less obvious today is that the spoken language has changed since the Chinese writing system was first invented, on top of the fact that the characters themselves evolve, so words with initially the same pronunciation might diverge, not to mention the divergence of the characters themselves. This can often obscure the Chinese writing system's highly phonetic nature. Like English and French, the Chinese writing system doesn't do a good job of updating itself with the spoken language. In fact, it would be rather hard to do that today, because Old Chinese has since diverged into a plethora of mutually-unintelligible language families (colloquially known as "dialects"). Such divergence shows further evidence of the necessity of a phonetic basis in a writing system, because each Chinese language has a "colloquial writing system", with different character sets, different vocabulary frequencies, different idioms, different word orders for different constructions. However, because the Chinese writing system itself is fairly stable, you can occasionally say, write a Mandarin phrase using Chinese characters and have a Cantonese speaker be able to interpret it -- but the effect is rather like reading Latin. Sometimes, speakers of different Chinese languages cannot interpret each other's writing at all!

Bloomfield posed more general arguments. He was arguing that as far as communication goes, the foundation of it is based on spoken language. Sure we can perform all sorts of symbolic operations in our heads, but when we fluently communicate such operations, we must use a system based on spoken language.

The mechanisms of reading and writing are pretty wondrous biologically -- they take advantage of the fact that we're capable of repeating sounds in our heads. There are various theories of memory based on this, as well as various theories of reading and language processing, and some exploration of the different types of working memory that might be involved linguistically -- as well as long-term acquisition of grammar and vocabulary (at an L1/native level -- second language learning is a bit more complicated). Some concepts that might be interesting to people working in phonics include Baddeley's model of working memory, including concepts like a "phonological loop". Of course the theory is highly incomplete, but it's a good place to start, and there are many experimental precursors to the model that demonstrate the necessity for a phonetic basis to reading.

For a writing system to express precise and fluent thoughts, it must be dependent on sound -- because that is the basis of communication. Sure there's art and music ... but you can't really communicate fluent and precise ideas with them, only gists. Could you communicate something like Newton's laws of physics to someone who didn't know them based on a picture, or a series of pictures? Take for example, the former practice of some of the Plains Natives to draw symbols on teepees for communciation -- such systems were really imprecise, and used for communication purposes that didn't have too many symbolic operations -- like "need bow-wood, twine; offer leather" or "off to river 3 days" as well as various artful depictions. In contrast, look at the complexity of many Native American languages, such as Cherokee and Sioux. Known as polysynthetic languages, they have high levels of inflection and morphological agreement, with agreement between subject, verb, direct and indirect objects, clauses. Certainly quite complex enough to express instructions on the precise order of steps to take to cook a buffalo recipe, explain the finer principles of riflemanship to a young child, suggest how you should take this flank to corner Custer and cut him off from the other Union troops, or argue why we need to stop the practice of counting coups because the situation dictates that our survival is dependent on seizing every defensive advantage possible.

You can't do this with teepee writing. There's just not enough complexity, or even vocabulary. The Chinese writing system probably evolved from a pictorial convention not unlike teepee symbols -- representing things for sale, things for buying, common objects, weather, etc. But as you wanted to use the system for more and more things, you got bogged down with the picture aspect. Really, try a convenient arrangement of symbols to symbolically depict the idea that Charlie tried to intercept a letter sent from Alice to Bob, but that Alice and Bob already know of his intentions and have come up with a plan to trick Charlie. The eureka moment was when the system switched from depicting ideas to depicting sounds. Sure, you're still using a little drawing of the sun to represent the word for sun, but now you can also use it for words with unrelated meanings (an English equivalent would be using a symbol for "sun" for the word "asunder", or combining it with a radical element related to "math" to make the word "sum"). The system exploded with the sudden possibilities. The side effect is that since you were now representing sounds and not ideas, you could drastically simplify many of the characters. Characters with elaborate depictions of mountains, trees and fields were reduced to series of short quick strokes to the extent that often you can't figure out what the character originally depicted.

There are some who argue that language is essentially a learned social construct, and this argument was probably in vogue during Bloomberg's day (the era also spawned the Sapir-Whorf hypothesis). If you can make a language on a phonetic basis -- why not one on an ideographic basis, or one that exists only in writing? But scientific evidence shows a huge biologically-determined component to language. Granted there is a huge memetic (culturally-transmitted) aspect, which is what makes it so fascinating to study (especially from an evolutionary dynamics standpoint), but an interesting thing to note is that the children of all the world learn their native language at around the same timelines. Indeed, intralanguage variance (for the time it takes for a child to learn to speak fluently) generally exceeds interlanguage variance by far. It's strong evidence that many aspects of language are human universals and are biologically/genetically constrained.

Tuesday, July 21, 2009

Working memory and the blind

We are talking about the huge swaths of children labelled "learning disabled" who can't read, but what about the actually disabled who learn anyway?

How do the blind learn to read, or compute, or do any of the tasks we think of as reading/writing/math?

Has anyone ever read anthing about the cognitive workings of the blind?

I increase my working memory by writing things down on paper and looking at what I've written.

How do they maintain working memory? Are the brilliant scholars who are blind particularly adept at maintaing working memory using braille? or do they just have fantastically larger working memory than the rest of us? How do they organize their working memory--do they do it "visually" to some degree? Or do they use other senses somehow? Is their auditory loop for working memory MUCH larger than mine, e.g.?

Anyone ever read any research on this? Or even any anecdotal memoirs?

Monday, April 7, 2008

John Medina's experimental high school

You recall that the hippocampus is wired to receive information from the cortex as well as return information to it. Declarative memories appear to be terminally stored in the same cortical systems involved in the initial processing of the stimulus. In other words, the final resting place is also the region that served as the initial starting place. The only separation is time, not location. These data have a great deal to say not only about storage but also about recall. Retrieval for a fully mature memory trace 10 years later may simply be an attempt to reconstruct the initial moments of learning, when the memory was only a few milliseconds old! So, the current model looks something like this:

1) Long-term memories occur from accumulations of synaptic changes in the cortex as a result of multiple reinstatements [spaced repetitions] of the memory.

2) These reinstatements are directed by the hippocampus [in the temporal lobe], perhaps for years.

3) Eventually the memory becomes independent of the medial temporal lobe, and this newer, more stable memory trace is permanently stored in the cortex.

4) Retrieval mechanisms may reconstruct the original pattern of neurons initially recruited during the first moments of learning.

[snip]

The day of a typical high-school student is segmented into five or six 50-minute periods, consisting of unrepeated (and unrelenting) streams of information. Using as a framework the timing requirements suggested by working memory, how would you change this five-period fire hose? What you’d come up with might be the strangest classroom experience in the world. Here’s my fantasy:

In the school of the future, lessons are divided into 25-minute modules, cyclically repeated throughout the day. Subject A is taught for 25 minutes, constituting the first exposure. Ninety minutes later, the 25-minute content of Subject A is repeated, and then a third time. All classes are segmented and interleaved in such a fashion. Because these repetition schedules slow down the amount of information capable of being addressed per unit of time, the school year is extended into the summer.

[snip]

In the future school, every third or fourth day would be reserved for reviewing the facts delivered in the previous 72 to 96 hours. During these “review holidays,” previous information would be presented in compressed fashion. Students would have a chance to inspect the notes they took during the initial exposures, comparing tem with what the teacher was saying in the review. This would result in a greater elaboration of the information, and it would help the teachers deliver accurate information. A formalized exercise in error-checking soon would become a regular and positive part of both the teacher and student learning experiences.

It is quite possible that such models would eradicate the need for homework. At its best, homework served only to force the student to repeat content. If that repetition were supplied during the course of the day, there might be little need for re-exposure. This isn’t because homework isn’t important as a concept. In the future school, it may simply be unnecessary.

Could models like these actually work? Deliberately spaced repetitions have not been tested rigorously in the real world, so there are lots of questions. Do you really need three separate repetitions per subject per day to accrue a positive outcome? Do all subjects need such repetition? Might such interleaved vigor hurt learning, with constant repetitions beginning to interfere with one another as the day wore on? Do you really need review holidays, and if so, do you need them every three to four days? We don’t know.

Years and years

Today, students are expected to know certain things by certain grades. Curiously absent from this model is how durable that learning remains after the student completes the grade. Given that system consolidation can take years, might the idea of grade-level expectations need amending? Perhaps learning in the long view should be thought of the same way one thinks of immune booster shots, with critical pieces of information being repeated on a yearly or semi-yearly basis.

In my fantasy class, this is exactly what happens. Repetitions begin with a consistent and rigorous review of multiplication tables, fractions, and decimals. First learned in the third grade, six-month and yearly review sessions on these basic facts occur through sixth grade. As mathematical competencies increase in sophistication, the review content is changed to reflect greater understanding. But the cycles are still in place. In my fantasy, these consistent repetition disciplines, stretched out over long periods of time, create enormous benefits for every academic subject, especially foreign languages.

Brain Rules, by John Medina
p. 141-142; 143-145

Brain Rules web site
hippocampus
Neuroscience for Kids

Wednesday, March 26, 2008

Cognitive Load Theory (CLT) For Beginners

Cognitive Load Theory (CLT) from Greg Kearsley's site, Theory into Practice:

Sweller's Cognitive Load Theory: Overview

This theory suggests that learning happens best under conditions that are aligned with human cognitive architecture. The structure of human cognitive architecture, while not known precisely, is discernible through the results of experimental research. Recognizing George Miller's research showing that short term memory is limited in the number of elements it can contain simultaneously, Sweller builds a theory that treats schemas, or combinations of elements, as the cognitive structures that make up an individual's knowledge base. (Sweller, 1988)

The contents of long term memory are "sophisticated structures that permit us to perceive, think, and solve problems," rather than a group of rote learned facts. These structures, known as schemas, are what permit us to treat multiple elements as a single element. They are the cognitive structures that make up the knowledge base (Sweller, 1988). Schemas are acquired over a lifetime of learning, and may have other schemas contained within themselves.

The difference between an expert and a novice is that a novice hasn't acquired the schemas of an expert. Learning requires a change in the schematic structures of long term memory and is demonstrated by performance that progresses from clumsy, error-prone, slow and difficult to smooth and effortless. The change in performance occurs because as the learner becomes increasingly familiar with the material, the cognitive characteristics associated with the material are altered so that it can be handled more efficiently by working memory.

From an instructional perspective, information contained in instructional material must first be processed by working memory. For schema acquisition to occur, instruction should be designed to reduce working memory load. Cognitive load theory is concerned with techniques for reducing working memory load in order to facilitate the changes in long term memory associated with schema acquisition.
From Kevin McGrew's blog, a guest post by Walter Howe, Cognitive Load Theory for School Psychologists:

  • Have you ever done something successfully, but not known exactly how you did it? It’s a common experience. It works, but we generally either cannot repeat this feat readily or transfer this performance to other, similar situations. We have performed a particular task successfully, but we haven’t really learnt a lot.
  • In CLT, this one-off success isn’t learning (in other theories it is regarded as learning, and termed implicit learning or procedural knowledge). Learning only occurs when we have abstracted a series of steps and rules that we can repeat in similar situations or even teach others so they, too, can be successful. These rules and procedures are called schemas or schemata and they are stored in long-term memory. Novices, by definition, either don’t have a schema for a particular learning task or it is very unsophisticated. Experts, on the other hand, have many, very sophisticated schemas, which they apply without thinking (i.e. the application of these schemas has become automatic).
  • CLT is concerned with how we learn or (in CLT terms), how we develop schemas and automate them and become experts. It applies to learning relatively complex material, as schema acquisition and development are generally unimportant for simple tasks, although how simple a task is depends both on the task itself and the individual who is learning how to do it successfully, as you will see.
Go read the whole thing, and while you are at it, poke around with Kevin McGrew's other posts on cognitive load theory and math, for starters.

CLT has obvious implications for the design of instruction in mathematics, among other things.

PS:
Kevin McGrew keeps a number of wonderful resources: IQ's Corner ("An attempt to share contemporary research findings, insights, musings, and discussions regarding theories and applied measures of human intelligence. In other words, a quantoid linear mind trying to make sense of the nonlinear world of human cognitive abilities.") Tick Tock Talk: The IQ brain clock ("An attempt to track the "pulse" of contemporary research and theory regarding the psychology/neuroscience of brain-based mental/interval time keeping. In addition, the relevance of neuroscience research to learning/education will also be covered.")

Tuesday, January 1, 2008

bigger & better

Lots of cool brain stuff at New Scientist.

Maybe I'll just forget the Book Club and spend my time hanging out on the web doing exercises intended to increase my working memory. (Sorry - I didn't write down the source that put me onto those two sites, but I remember it being serious.)

UNTIL recently, a person's IQ - a measure of all kinds of mental problem-solving abilities, including spatial skills, memory and verbal reasoning - was thought to be a fixed commodity largely determined by genetics. But recent hints suggest that a very basic brain function called working memory might underlie our general intelligence, opening up the intriguing possibility that if you improve your working memory, you could boost your IQ too.
Working memory is the brain's short-term information storage system. It's a workbench for solving mental problems. For example if you calculate 73 - 6 + 7, your working memory will store the intermediate steps necessary to work out the answer. And the amount of information that the working memory can hold is strongly related to general intelligence.
A team led by Torkel Klingberg at the Karolinska Institute in Stockholm, Sweden, has found signs that the neural systems that underlie working memory may grow in response to training. Using functional magnetic resonance imaging (fMRI) brain scans, they measured the brain activity of adults before and after a working-memory training programme, which involved tasks such as memorising the positions of a series of dots on a grid. After five weeks of training, their brain activity had increased in the regions associated with this type of memory (Nature Neuroscience, vol 7, p 75).
Perhaps more significantly, when the group studied children who had completed these types of mental workouts, they saw improvement in a range of cognitive abilities not related to the training, and a leap in IQ test scores of 8 per cent (Journal of the American Academy of Child and Adolescent Psychiatry, vol 44, p 177). It's early days yet, but Klingberg thinks working-memory training could be a key to unlocking brain power. "Genetics determines a lot and so does the early gestation period," he says. "On top of that, there is a few per cent - we don't know how much - that can be improved by training."

As far as I can tell, the idea that working memory is highly related to IQ is solid and not likely to be significantly revised any time soon. I have the impression that, for awhile there, neuroscientists were thinking that IQ might actually be working memory, but that hypothesis seems to have been abandoned.

Wednesday, November 28, 2007

brute memorization

Terrific post from Instructivist on the subject of memory and memorization.

This is something I've struggled with: how to distinguish "brute memorization" (my term for it) from "natural memorization" or, in instructivist's phrase, "thoughtful memorization."

Constructivist philosophy defines the word "memorization" as most folks do: the student sits down with a set of flash cards and commits material to memory.

I assume (don't know) that the flash card approach is essential in some realms: foreign language courses, law school, med school.....yes?

But "brute memorization," generally speaking, probably isn't the best way to go about acquiring knowledge, and is not the method a knowledge-focused curriculum like Saxon Math employs.

Unfortunately, we don't have a term for the kind of memorization Saxon Math induces.

Saxon Math produces memorization via spaced repetition, which is, I believe, the way everyday life produces memorization.

Here is my sense of the way in which natural memorization works:

  • content to be committed to memory is broken into the smallest meaningful units
  • the smallness of the units allows each unit to be held in working memory (or consciousness) in its entirety

  • in time the units being practiced naturally enter long-term memory

This seems to be the way most material enters long-term memory in the day to day. One repeatedly encounters and/or practices an idea or skill until one simply "has it."

Example.

I'm going to guess that quite a few ktm readers and commenters now possess a usable or at least semi-usable definition of the term working memory.

Did you acquire this by sitting down with a flash card and rotememorizing it?

No.

You acquired a usable knowledge of working memory by repeatedly encountering the term in posts and comments until you remembered it.

This process is natural, and it is inevitable. Memory is a core function of the brain; people who don't remember things have brain disorders. Bad ones.

Constructivist antipathy to memory and remembering is quite perverse -- it is unnatural, as a matter of fact -- but it is consistent with constructivist antipathy to knowledge.

The brain naturally acquires knowledge. Yes, I know the brain does not naturally acquire knowledge of algebra absent a good textbook and teacher ( ! )

However, if you have a good textbook and/or teacher it is entirely natural to acquire knowledge of algebra whether you give a damn about algebra or not. As a matter of fact, it's entirely natural to acquire some knowledge of algebra even with a mediocre textbook and a so-so teacher. Repeated practice causes us to remember what we've practiced, period.

If you don't want students acquiring knowledge, you're going to have to oppose memory and memorization.

.....................................

As to direct memorization and its place in formal education or in any training program, my sense is that it is often the fastest route to remembering. From time to time Saxon will tell the student, "Memorize this." His meaning is always: You're going to need this, you're going to use this, just go ahead and memorize it.

Direct memorization is a shortcut.

I think.

.....................................

hmmm...

Direct memorization
probably isn't a bad term for the kind of simple, straightforward, put-it-on-a-flashcard-and-practice-it memorization constructivists call "rote."