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Thursday, December 04, 2008

Make Them Learn: With Carrot or Stick?

Feedback is essential for learning. Not only does the feedback need to ensure that learning was achieved (as in testing), but feedback also needs to reinforce the motivation to learn. The age-old questions arises: do we use the carrot or the stick? Which works best, negative or positive reinforcement? Most people have an opinion, but now we have scientific studies of the question. And the answer is, it depends.

For example, three studies showed that adults correct their behavior better in response to negative feedback rather than positive feedback, whereas 8- to 11-year old children respond just the opposite. A follow-up study by Anna van Duijvenvoorde and colleagues in the Netherlands used MRI scans to examine how the brain changes with age and how that relates to feedback-based learning. The subjects were divided into three age groups, 8-9, 11-13, and 18-25. Each subject performed the same learning task and were given positive and negative feedback to improve their performance. After each trial, subjects were shown on a screen an “X” or a “+” to tell them they were wrong or right.

Regardless of the nature of the feedback, young adults learned bdetter than the children. For all three age groups, learning was more effective with positive feedback. Moreover, the decreased learning from negative feedback was conspicuously greater in the youngest age group, while in the young adults, the effect of feedback type was negligible.

Not surprisingly, there were brain scan indicators of differing response to type of feedback. With age, both types of feedback produced a shift toward recruiting more activity in the dorsolateral prefrontal cortex. This part of the cortex was more active after negative feed back in adults but after positive feedback in the 8-9 year-old children. The prefrontal cortex activity was about the same for negative and positive feedback in the 11-13 year olds, suggesting that this is a transition stage in development of learning style and capability.

Take home message? Positive feedback usually works best in young children (that is, after all, how they train seals). Negative feedback works just about as well as positive feedback in young adults. One more point: with the exception of language acquisition, young children are not the superior learners that many people believe.

Source: van Duijvenvoorde, A. C. K. 2008. Evaluating the negative or valuing the positive? Neural mechanisms supporting feedback-based learning across development. J. Neuroscience. 28 (38) 9495-9503.

Monday, November 10, 2008

Negative Emotions and Memory

I have a big section in my memory book on the interference with memory formation caused by negative emotions. I have seen first hand how emotional crises cause the grades of college students to plummet. Whenever a good student suddenly starts making poor grades, I know this student has recently had an emotional trauma. Common problems for college students include trouble making friends, boy/girl problems, parent divorce, homesickness, financial worries―grades invariably suffer.

Recently, I had a reader of this blog challenge my position, pointing out that the most severe form of negative emotions, post-traumatic stress (PTSD), has as its main problem the inability to forget the events that triggered the PTSD. My reader is of course correct. But so also is all the evidence that negative emotions interfere with memory. How do I reconcile these incompatible views?

What is so well-remembered in PTSD are the traumatic events that caused the negative emotions. That is not the same as saying that PTSD patients have exceptional ability to remember other things or learn new things. I contend that their memory for new learning is impaired because of their distressed emotional state. The reason they remember the PTSD events so well is because they rehearse them so often.

All intense situations, even happy ones, tend to be well-remembered because of the intensity of the stimuli and the fact that such situations are repeatedly rehearsed. Rehearsal usually occurs immediately, because of the intensity of stimulation, and is repeated frequently, because the situation had such a big emotional impact. It is not so much the positive or negative aspect of the situation that matters for memory formation, but rather the timing and frequency of rehearsal.

Why do negative emotions interfere with new learning? I haven’t seen formal studies of this question, but what I know about memory allows some useful speculation. First, feelings such as worry, fear, depression, loneliness, and the like, have devastating effects on motivation. Under such conditions, nobody feels much like taking on challenges. Negative feelings also make it hard to pay attention to anything else besides what is causing the emotional distress. Attentiveness is pre-requisite for forming memories of new learning. Negative feelings lead to persistent negative thoughts, and thinking about one thing while trying to memorize another just doesn’t work. Negative feelings also erode confidence and sense of well being, both of which are essential for optimal memory ability. Why confidence and sense of well being are important is unclear, but I suspect they motivate a person to do what it takes to achieve personal goals. In the case of memory ability, it is easier for an up-beat person to take on learning challenges and to do the right things for promoting memory formation.

Wednesday, October 15, 2008

Internet Is Better for the Brain than Books?

A new brain imaging study showed that going online stimulated larger parts of the brain than the relatively passive activity of reading a novel or non-fiction book.

The science writer, Richard Alleyenne, of the lay article claims that this proves that Internet browsing is better for brain development than reading books. The scientists involved in the research seem to agree. Here are quotes from the article:

It was so stimulating that the authors of the study believe it could actually help people maintain healthier brains into their old age. The study results are encouraging, that emerging computerised technologies may have physiological effects and potential benefits for middle-aged and older adults," said principal investigator Dr Gary Small, a professor at the Semel Institute for Neuroscience and Human Behavior at University of California. Internet searching engages complicated brain activity, which may help exercise and improve brain function." The study, the first of its kind to assess the impact of internet searching on brain performance, is published in the American Journal of Geriatric Psychiatry.

Well, before you tell schools to throw away the textbooks and let the kids browse away, you should know this: when a brain lights up in many places, it means the brain does not know how to deal with all the stimuli. It has not mobilized or focused its neural circuitry to deal with the stimuli efficiently and effectively. In most imaging studies I have read, when a brain knows how to cope with a task, FEWER areas light up. In other words, a brain works best when it can focus its resources. If you want your kids to grow up scatterbrained, put them on the Web. If you want them to develop longer attention spans and improve critical thinking skills, have them read good books. Their brain will thank you.

Sunday, September 28, 2008

Reading comprehension: role of eye movements

The capacity of working memory, for example the number of digits in a phone number you can hold long enough to dial it, determines how well you can think and the ability to form lasting memory. I have explained this in my book, Thank You Brain For All You Remember. New insight into working memory capacity has recently been reported by Paul Bays and Masud Husain in a research report in Science. They studied the capacity for visual memory, that is, the number of visual objects a person can hold in working memory. In the study, the emphasis was on the role played by eye fixation.

The design was to display four geometric shapes on a screen, each with a different color. The subjects viewed the screen without moving their eyes, and then the screen was blanked. Next, one of the items was redisplayed, but in a different location and rotation. The working memory task was to remember the original orientation and location. The objects were then withdrawn. Typically, subjects recalled well as long as the set size was no larger than four and as long as the probe object was not changed much. But precision of recall fell off drastically, even with only two or three objects, if the probe object was moved significantly.

Next, they wanted to explore the effects of moving the eyes across the stimulus field. Actually, this presents a major challenge to the brain, because more information has to be held in working memory. Even so, the results when eye movement was allowed and when it was not seemed about the same. The decline in accuracy depended mostly on the number of objects in the set. This suggests that the brain parcels out the task so that memory resources are assigned proportionately to each item. But eye movements are important. In another study, subjects made a series of eye movements to fixate on each item in a five-set display, and the screen was blanked just before the fifth item was fixated. Then subjects were tested to report the location and orientation of the objects. Accuracy was greatest for the fifth item, presumably because the brain had allocated more of its memory resources to registering the item the eyes were about to fixate. This, of course, is being done at the expense of remembering all of the previous four fixations.

These facts must have profound implications for reading comprehension. Certainly, these data seem to support the value of “whole reading” theory, which emphasizes fixing eyes on whole words, preferably where one eye fixation takes in several words.* The point is that if brain allocates more of its memory resources to each upcoming eye fixation, then reducing the number of fixations ought to increase comprehension, as indicated by working memory of what is seen with each fixation. In other words, the brain can process the meaning of multiple words in an upcoming fixation because the brain is devoting more memory resources to the next fixation task.


*This is not to denigrate phonics, for there is compelling evidence that phonics is the best way to learn words in the first place. But once learned, remembering the words you read is probably best achieved by reducing the number of eye fixations.


Bays, P. M., and Husain, M. 2008. Dynamic shifts of limited working memory resources in human vision. Science. 321: 851-85

Sunday, August 24, 2008

What You Can do to Improve Memory (and Why It Deteriorates in Old Age)

As a regular columnist for the newsletter, Sharp Brains - The Brain Fitness Authority, I have just posted an article that might interest those of you whose slipping memory reminds you that you are getting older. The article summarizes research that explains why memory often deteriorates with old age. But it does not have to decline, and the article suggests things you can do to delay or even prevent memory decline. "Eat your blueberries" is only a part of the answer. I present the evidence that as you get older your thinking style has to change. The article suggests ways to do that.

Click here to see the article. Searching on "Klemm" will lead you to other articles I have written for the brain fitness newsletter. And don't forget to order my book, which is pre-requisite to getting the most out of these blog and newsletter posts. The Website now sells it for less than Amazon.

Tuesday, August 12, 2008

Working Memory Training Raises IQ of Adults

I have pointed out in an earlier post how training young children to increase their working memory capacity will increase their IQ. This same phenomenon has now been demonstrated in young adults (mean age = 25.6 years).

Subjects were pre-tested on an IQ test involving visual analogy problems of increasing difficulty. Each problem presented a matrix of patterns in which one pattern was missing. The test was to identify the missing pattern from a set of alternatives. After training or a control without training, the test was repeated and scores compared.

The working memory task consisted of presenting at the same time two short series of stimuli, one visual and one auditory. The visual stimuli consisted of a small white square positioned at one of eight locations on a black screen and presented sequentially every three seconds. After seeing the series, the subject was tested with a test screen and asked to say if it matched the screen that was presented some n-number of screens earlier. This is a standard n-back paradigm often used to test working memory capacity. The n was adjusted to performance level and increased as subjects became proficient at remembering 2, then 3, etc. prior screens. A similar protocol was used for the auditory task, which involved hearing a recording of the sounds of a sequence of alphabet letters, with subjects asked to tell if a target test sound was the same as one they had heard 2, 3, or more sounds earlier.

Both working memory capacity and IQ improvements were seen in as little as 8 daily training sessions, and subjects steadily improved as training was extended to 19 days of training.


Jaeggi, S. M. et al. 2008. Improving fluid intelligence with training on working memory. Proc. Natl. Acad. Science.

Tuesday, July 15, 2008

Memory Consolidation Issues

I am one of the columnists for Sharp Brains. I just posted a review article on some key issues for memory consolidation. These deal with such subjects as over-training, forgetting of things you once knew extremely well, and the learning effects of testing. Check it out at

Friday, July 11, 2008

I just released a new book, Blame Game. How To Win It. Although it is based more on general psychological principles, one of the five chapters explains how learning and memory changes the brain, chemically and structurally, and thus provides a way to change behavior permanently. The book's thesis is a five-step program for living the good life. Think of it as "debt relief" for the high costs of excuse-making. Prominent psychologists have endorsed the pre-publication version. Check it out at Amazon or at your local bookstore (official release date is July 24).

Updating Existing Memories Also Requires Consolidation

As a newly forming memory develops (see chapter on memory consolidation in my book), it is susceptible to disruption by mind wandering, other stimuli, distractions, etc. When a new memory is retrieved, a re-consolidation process will be required if updated information needs to be incorporated. Such re-consolidation involves a new round of protein synthesis in brain cells, similar to that which is needed to make the initial learning a lasting memory. Likewise, a re-consolidation process must be protected from disruptive influences if the updated information is to be integrated and consolidated with the original learning.

There is good news and bad news here. The good news is that new information can update and be integrated with old memories. Recall also my earlier post on the possible use of this principle with treatment of Post-traumatic Stress Syndrome. The bad news is that old memories become vulnerable to corruption with each new re-consolidation, leading perhaps to false memories. My book has a whole chapter on false memory.

Source: Rodriguez-Ortiz, C. J. et al. 2005. Spatial memory undergoes post-retrieval consolidation only if updating information is acquired. Soc. Neuroscience Abstract 654.20.

Monday, June 30, 2008

Omega 3 May Reduce Odds of Alzheimer’s Disease

In mice, rats, and cultured human cells, an omega-3 fatty acid found in algae called docosahexaenoic acid, or DHA, was found to decrease an important risk factor for late-onset Alzheimer's disease. DHA increases the production of a protein vital to clearing the brain of the enzymes that make the beta amyloid plaques found in Alzheimer's disease.

Alzheimer's patients are known to have reduced levels of this protein that normally would clear the plaque-making enzymes. This data suggest that long-term use of DHA supplements might help people reduce the odds of developing Alzheimer’s disease.

The National Institutes of Health is now funding a multi-million dollar clinical study on the effects of vegetarian DHA from microalgae in slowing the progression of Alzheimer's disease. This DHA is a vegetarian form of omega-3, which supports brain, eye and cardiovascular health throughout life. I have mentioned the value for omega 3 in an earlier blog. Most people don’t get enough omega 3 in their diet. But it is not just the amount of DHA that is important, but also its ratio to another fatty acid, omega 6. A typical Western diet produces a ratio ranging from 1:10 to 1:30, where ideally it should be 1:5 to 1:3.

Fish oil is the usual source of DHA, but the algae source is vegetarian and may have fewer ocean contaminants. It is made by the Martek Biosciences Corporation (


Ma, Qie-Lan, et al. 2007. Omega-3 fatty acid docosahexaenoic acid increases SorLA/LR11, a sorting protein with reduced expression in sporadic Alzheimer's Disease (AD): Relevance to AD prevention. Journal of Neuroscience, 27(52):14299-14307.

Saturday, May 31, 2008

Help Your Working-memory Capacity

I just read a fascinating book on increasing teacher awareness of the importance of working-memory capacity for teaching and learning strategies. Many youngsters have working memory limitations, and they usually do not grow out of them. This is a major and serious cause of low grades, poor learning skills, poor confidence, and life-long diminished motivation to learn.

Limited working-memory capacity impairs the ability to think and solve problems. I was told once by a middle-school teacher that her “special needs” students could do the same math as regular students, but they just can’t remember all the steps. This clearly reflects a limited working-memory capacity. If the demands made on working memory could be lessened, better thinking could result.

Certain strategies can help to reduce the load on working memory. Teachers should model and students should employ the following devices:

Provide help, cues, mnemonics, reminders.

KISS (Keep It Simple, Stupid!)(example: use short, simple sentences, present much of the instruction as pictures/diagrams).

Don’t present so much information. Less can be more.

Facilitate rehearsal, using only relevant information and no distractors.

Get engaged, by taking notes, and creating diagrams and concept maps.

Attach meaning from what is already known. (The more you know, the more you can know).

Organize information in small categories.

Break down tasks into small chunks. Master each chunk sequentially, one at a time.

Doing these things not only helps the thinking process, but will also promote the formation of lasting memories. The process of converting working memory into permanent form is called consolidation, and I will explain that next time.


Gathercole, Susan E., and Alloway, Tracy P. 2008. Working memory and learning. Sage Publications,. 124 pages.

Friday, May 09, 2008

Core Neuroscience Ideas

Readers of this blog who want to have a fuller understanding on how the brain achieves learning and memory may want to know about my new e-book on Core Ideas In Neuroscience.

This modular e-book is a new kind of neuroscience textbook that can liberate professors and students from the boredom of traditional lectures. The book is designed for psychology, medical, allied health, and biology students and professionals who are tired of textbooks that tell them more than they want to know and who don’t want to spend over $100 for their neuroscience book.

This is the fast and inexpensive way to get up to speed on the core ideas in neuroscience.

Benefits for students include: important things are made explicit. Less material is easier to comprehend quickly and to remember. Book’s focus on ideas promotes active learning, critical thinking, insight and understanding. Benefits for professors include: no need to worry about students missing the important information; key concepts are succinctly presented in the book. Class time can be used for more engaging material, such as discussion and debate, clinical case studies, journal club, or design of new experiments. Each of the 75 core ideas is generally treated as a 3-5 page module in which the idea is succinctly stated and explained, with key terms defined. Then, a couple of examples are given, followed by contemporary and classic references. The book has 174 study questions, 96 figures, 545 references (including 306 citation classics), and 566 e-pages. It costs only $11.95, just 16 cents per idea.

Friday, April 04, 2008

Giving Up Can Help Tip-of-the-Tongue States

All of us have had those tip-of-the-tongue (TOT) states where we just can't recall a friend's name or some fact just when we need it. I discuss this phenomenon on pages 198 to 206 of my book. I explain how to deal with this problem by staying calm and trying to recall all the cues associated with what you are trying to remember.

But what if you did not use many cues when you first formed the memory? In those cases, the remedy should perhaps be different. Two psychologists at McMaster University in Ontario recently published a study showing that trying hard to retrieve a TOT memory may be counterproductive. They studied 30 volunteers who were shown definitions to words they did not know. Some definitions were easy, some were hard, and some were fakes. When tested for recall, subjects were instructed to press a button any time they encountered a TOT state. When subjects entered a TOT state they were told to keep trying and they would be told the answer in 10 or 30 seconds if they don't get it.

Subjects were re-tested two days later by being asked to generate the word that fit each definition. Researchers found that subjects had a high probability of stumbling again on the same words they had trouble with the first time. TOTs were almost twice as likely to happen again on words that initially caused a TOT and had been followed by a long delay than on those that had been followed by a short delay. One conclusion is that failing the first time is actually an implicit learning condition wherein subjects are learning to fail again. The longer they kept trying, as in the 30-second group, the more time they had to learn to fail.

These subjects had not been instructed to make visual images of words and their definitions during initial learning. Had that been done, there might have been fewer TOTs the second time and those that did occur could probably have been resolved by thinking of the cues.

So, the next time you have a TOT for somebody's name or some fact, first think of all the cues you can. If cues don't come to mind, you probably should quickly move on mentally to something else and periodically come back to the item that caused your TOT state. When the answer finally does come to you, make as many associations as you can that can serve as cues the next time.

Soucre: Warriner, A. B., and Humphreys, K. R. 2008. Learning to fail: recurring tip-of-the-tongue states. Quaterly J. Exp. Psychol. 61: 535-542.

Monday, March 31, 2008

Learning to Learn II – Learning Can Increase the Biological Capacity to Learn

I explained in my book on memory that the hippocampus is the brain structure that promotes consolidation of (declarative) short-term memories into long-term memories. I have also reviewed studies showing that the hippocampus is the one structure in the brain that clearly receives newborn nerve cells, even in the adult. New cells can enhance the ability of the hippocampus to create lasting memories. What has not been emphasized is the importance of survival of new neurons. To be of lasting benefit, new neurons must survive beyond just being born.

Insight into the requirements for neuron survival has come in a recent study by J. R. Epp and colleagues at the University of British Columbia. They injected rats with a chemical marker for DNA that shows up in any new DNA, that is in any newly born cells. If that marker shows up in a cell, it means that that this is a new cell that has incorporated the marker along with its new DNA.

Immediately after injection of the marker, the experimenters trained the rats in a large pool of water that had a safe platform located 2 cm under the water surface where rats could learn its location from seeing cues outside of the pool (such as windows, doors, pictures on the wall, etc.). Other studies had established that learning this task is accomplished by the hippocampus. Rats were divided into groups and trained on days 1-5, 6-10, or 11-15 after injection of the DNA marker. The new-DNA marker showed up only in rats trained on days 6-10 after marker injection. This indicated that there must have been new neurons in the hippocampus of these rats that did not survive in the two groups where marker was not seen. Put another way, for new neurons to survive there is a critical period where they have to be stimulated by learning experiences. Without that stimulus, they die.

Earlier studies had shown that new neurons in rat hippocampus have a development cycle wherein 6-10 days after birth is a middle stage of development in which new neurons are rapidly sending out membrane processes in search of contacts with other neurons. When neurons make contact with targets they can survive. The stimulus of learning thus provides a stimulus for forming new synapses with other neurons, thus enabling new neurons to survive.

The data were originally pooled across all rats in each test group. However, when the data were segregated by how well rats learned (the top and bottom 50 %), it became clear that it was only the poor learners that were showing an effect on new-neuron survival by maze learning. Poor learners probably got more stimulation from the learning because their brains had to work harder at it. It wasn’t that much of a mental challenge for good learners.

We know that humans are continually producing new neurons in the hippocampus. The issue is the need to experience enough demanding learning to help these new neurons survive. The critical period for learning to influence new-neuron survival in humans is not known. So, the practical take-home message is that we need to be learning constantly, every day, so that no matter what the critical period is, we will be helping our new neurons to survive. Survival of new neurons means a greater biological capacity for learning, at least in people who are not good learners. In other words, here is a clear case where the “poor get richer.”

Source: Epp, J. D., Spritzer, M. D., and Gales, L. A. M. 2007. Hippocampus-dependent learning promotes survival of new neurons in the dentate gyrus at a specific time during cell maturation. Behavioural Neuroscience. 149: 273-285.

Thursday, March 20, 2008

Learn One Movement Skill At a Time

"Motor memory" refers to a mental model (MM) that the brain constructs from past experience. In the example given by researchers Reza Shadmehr and Thomas Brashara-Krug, when a person plans to pick up a brick, a MM of the amount of force required to pick up the brick is used to execute the action.The brain does not estimate the force as if it were a feather nor if it were a sack of cement, rather it uses its memory of what a brick weighs to create a model of how much force will be needed to pick it up.

In the studies they reported, they used a robotic arm that subjects used to manipulate objects. In learning how to use the mechanical arm, subjects had to create a MM of how to make it do what they wanted. Like other kinds of learning, the MM is consolidated with practice into long-term memory.Moreover, motor performance continues to improve, even after actual practice has stopped, indicating that the MM itself may be subconsciously rehearsed, off-line so to speak.

Motor memory processes have great applicability in everything from learning to touch-type to learning to throw a football to a moving target. The study by Shadmehr and Brashara-Krug explored the finding that a recently acquired MM (MM1) can be disrupted if a second MM (MM2) was introduced too soon after MM1.That is, a MM1 has to have enough time to consolidate, just as declarative memories do.

Also, a MM1 can interfere with learning a MM2, if there is not enough time separation between learning the two motor tasks.This was demonstrated in the present study by having 60 subjects learn how to make two conflicting movements using the robotic arm. The MM for both tasks could be learned but only if the training sessions were separated by at least 5 hours. If the interval was shorter, learning of the second MM (MM2) was impaired, as was the likelihood of consolidating the first MM.

The “take home message” of this research is that learning different movement tasks should be separated in time, lest there be interference with forming long-term memory of both tasks. My explanation is the following: Once MM1 gets consolidated (that is, after about 5 hours), the circuits that sustain its short-term representation now become available for learning a second motor memory (MM2). That is, MM1 has proactive interfering after-effects that dissipate with consolidation of the MM1 and thus no longer interfere with learning an MM2.

Athletic coaches might be well advised to ponder the application of this principle.

Shadmehr, R., and Brfashers-Krug, T. 1997. Functional stages in the formation of human long-term motor memory. J. Neuroscience. 17(1): 409-419.

Wednesday, February 27, 2008

Tests Produce Learning

Tests do more than just measure learning. Tests are learning events. That is, testing forces retrieval of incompletely learned material and that very act of retrieval helps to make the learning more permanent. Testing, and not actual studying, is the key factor on whether or not learning is consolidated into longer term memory.

A recent experiment by J. D.Karpicke and H. L. Roediger at Washington University in St. Louis, examined the role that retrieval had on the ability to recall that same material after a delay of a week. In the experiment, college students were to learn a list of 40 foreign language vocabulary word pairs, which were manipulated so that the pairs either remained in the list (were repeatedly studied) or were dropped from the list once they were recalled. It is like studying flash cards: one way is to keep studying all the cards over and over again; the other way is to drop out a card from the stack every time you correctly recalled what was on the other side of the card. In the experiment, after a fixed period of study time, students were tested over either the entire list or a partial list of only the pairs that had not been dropped. Four study and test periods alternated back-to-back. Students were also asked to predict how many pairs they would be able to remember a week later, and their predictions were compared with actual results on a final test a week later.

The initial learning took about 3-4 trials to master the list, and was not significantly affected by the strategy used (rehearsing the entire list or dropping items out as they were recalled). On average, the students predicted that they would be able to remember about half of the list on a test that was to be given a week later. However, actual recall a week later varied considerably depending on learning conditions. On the final test, students remembered about 80% of the word pairs if they had been tested on all the word pairs, no matter whether they had been studied multiple times with all of them in the list or if they dropped correctly recalled words from the list in later study trials. However, recall was only about 30% correct when correctly identified words were dropped from subsequent tests, even though all words were studied repeatedly. In other words, it was the repeated testing, not the studying, that was the key factor in successful longer-term memory.

So, what is the practical application? When using flash cards, for example, you need to follow each study session (whether or not you drop cards from the stack because you know them), with a formal test over all the cards. Then, repeat the process several times, with study and test epochs back-to-back. Can we extend this principle of frequent testing to other kinds of learning strategies? Probably. But there are no formal experiments.

Let us speculate on the case of trying to remember names of people at a party. You might study the name of each person by using it in conversation or associating the name with some feature of the person's anatomy or personality. Then, silently quiz yourself, looking at the person and asking yourself to recall the person's name. Then, repeat the study-and-test process several times. You would have to keep number of people low (say four to six), because you may not have many opportunities to hear the name repeated other than your own repeating it in conversation. In most practical learning situations, you will not be given repeat tests immediately after each study session, so you must simulate that with self-tests.

Why does forced recall, as during testing, promote consolidation? It probably relates to other recent discoveries showing that each time something is recalled the memory is re-consolidated. If the same information is consolidated again and again, the memory is presumably reinforced.

The failure of students to predict how well they would remember is consistent with my 40 years experience as a professor. Students are frequently surprised to discover after an examination that they did not know the material as well as they thought they did. Tests not only reveal what you know and don't know, they serve to increase how much you eventually learn. If I were still teaching, I would give more tests. And I would encourage students to use self-testing as a routine learning strategy, something that one study revealed to be a seldom-used strategy. The repeated self-tests should include all the study material and not drop out the material that the student thinks is already mastered.

Source: Karpicke, Jeffrey D., and Roedinger, Henry L. III. 2008. The critical importance of retrieval for learning. Science. 319: 966-968.

Saturday, February 23, 2008

Overtraining: You Can Learn Too Much

Naps may be helpful for learning tasks other than those involving movement (see earlier note on work by Korman et al.).* An early study on the effects of napping had developed a useful texture discrimination task in which a visual display of horizontal bars has superimposed on it a brief display of three diagonal bars, followed by a blank screen, and then by a mask. The interval between the target and the mask is varied and the interval needed to achieve 80% correct responses is used as a measure of perceptual ability and working memory.

After a single training session, performance on this task improves only after subjects have had a normal night's sleep after the day's training. To be effective, a normal amount of dream sleep, which occurs mostly in early morning, is needed.

In a follow up study by another investigator, subject performance unexpectedly deteriorated if they were given 60-minute training sessions four times at regular intervals on the same day. In other words, the more the subjects were trained, the poorer they performed. However, this interference did not occur if subjects were allowed to nap for 30-60 minutes between the second and third sessions.

It is hard to explain why over-training disrupts performance, but one has to suspect that as training trials are repeated the information starts to interfere with memory consolidation, perhaps because of boredom or fatigue in the neural circuits that mediate the learning. Napping must have a restorative function that compensates for the negative effects of overtraining. What all this suggests to me is that memory consolidation would be optimized if learning occurred in short sessions that are repeated but only with intervening naps and on different days with regular night-time sleep. In other words, repeating long study periods in the same day on the same task can be counter-productive. This is yet another reason why students should not cram-study for exams. Learning should be optimized by rehearsing the same learning material on separate days where normal sleep occurred each night.

See my book on what science reveals about improving everyday memory. I also give seminars and workshops.


Maquet, P. et al. 2002. Be caught napping: you're doing more than resting your eyes.Nature Neuroscience. 5 (7); 618-619.

Mednick, Sara, et al. 2002. The restorative effect of naps on perceptual deterioration.Nature Neuroscience. 5 (7): 677-681.

Friday, February 01, 2008

Improve Reading Efficiency and Comprehension

Reading To Remember

Get the mechanics right

○ Make eye contact with all the text not being deliberately skimmed
○ See multiple words in each eye fixation
○ Strive to expand the width of each eye fixation (on an 8.5" width, strive
for three fixations or less per line)
○ Snap eyes from one fixation point to another (horizontal snaps on long
lines, vertical snap if whole line can be seen with one fixation)
○ Get formal training from a reading center if needed


○ Know what you are looking for. Identify the material that satisfies the purpose for which you are reading.
○ Skim the reading material first
  • primes the memory
  • orients the thinking
  • think about the headings: they identify what can be skimmed rapidly, what needs more thoughtful reading

○ Read with a purpose.
○ THINK about what you read. The more you think about it, the more you will remember. Ask yourself questions about what you read, as you are reading and afterward.
  • Is it satisfying your purpose?
  • How does it relate to what you already know? ... and need to know?
  • What is not said that should be?
  • What is said that you think is wrong or needs elaboration?
  • What do you not understand?
  • What needs special effort to remember?
  • How can you use this understanding and information?

○ Pause and rehearse (after every minute or so, for example)
○ For each new reading segment, ask “How does this build on what I just read?”
○ Reading sessions should be limited (15 to 30 minutes)
○ At the session end, rehearse what you learned - right away, without distractions. Answer again the questions mentioned above.
○ Think about and rehearse what you read at least twice later that day.
○ Rehearse again at least once for the next 2-3 days.

Monday, January 28, 2008

Computer Slide Shows. A Trap for Bad Teaching

Teachers at all grade levels are increasingly using computer slide shows (like MS PowerPoint shows) to present information. Such slide shows are also common in corporate and government briefings. Such slide shows typically violate many of the principles for good remembering. In this article, published in the education journal, College Teaching, I explain what slide shows typically do wrong and suggest ways to make the content of slide shows more memorable. Click here to read.

Tuesday, January 22, 2008

What Good Is Learning If You Don't Remember It

I had a paper published in Journal of Effective Teaching that I hope teachers will take a look at. It can be found on-line by clicking here.

Here is the abstract:

Teachers should emphasize the educational importance of understanding, but not at the expense of overlooking the importance of memorization skills. Currently, mainstream educational theory embraces such attributes as insight, creativity, inquiry learning, and self expression. But such emphases lead to a bias and under-appreciation of the role of memory in learning. Students cannot apply what they understand if they don’t remember it. Moreover, a good memory expands the repertoire of cognitive capabilities upon which new understandings can be developed and expedited. Effective thinking does not occur in a vacuum. I advocate adding another “R” to the “three Rs”: Reading, wRiting, aRithmetic, and Remembering. This paper attempts to show teachers how they can help students become better learners — and better thinkers — by improving their memorization skills.

Please comment.

Seven Tips for Learning from Lectures:

In this post I list seven tips you can use when trying to remember the contents of a seminar or lecture. These tips are especially useful for students. Forty-three years of college teaching have made it clear that most students don't get as much out of lectures as they should (and it is not just because of my lectures). When I was a student, I wanted to learn efficiently, so I could have more play time. I soon discovered that everything I could learn in class was something I did not have to study later.

The basis for these tips comes from my book on improving memory and from the posts in this blog. Obviously, I can't review all that here. Take my word for it, these tips work. Please comment to tell me what you have learned about learning effectiveness and efficiency during lectures.

The Tips:

1. Come with the right attitude. Be pumped up. Plan to retain as much understanding and information as possible. As long as you are spending your time in class, you might as well get out of it all you can. Don't be willing to put off the learning until later study time.

2. Do at least a little pre-lecture preparation. Skim text or other sources that deal with the topic of the day. If lectures are inter-related, briefly review previous notes of lectures that this current lecture will build on.

3. Don't take many notes. Take notes only for organizing ideas and for things you don't already know or could figure out. Use a tape recorder if you worry about missing something.

4. Make notes with multiple visual and spatial cues. Use lots of drawings and diagrams.

5. If allowed, ask questions of the teacher. This helps to keep you alert and engaged. Remember the answer. If you have asked good questions, they are liable to show up on quizzes (teachers like to quiz on ideas that come up in class that are not in the book or handouts - its a reward for those who attend and pay attention).

6. THINK about what is being said by the teacher. How does this build on what has been presented in the course earlier? What issues are not getting addressed by this lecture? What is most likely to show up on a quiz? What will take special effort to remember? How can you use this information, either later in this course or in another course?

7. After the lecture:

a. Don't do anything for the next 10 minutes. Without interruption, review what has just transpired, first by looking at your notes, then trying to recall without lookng.

b. Re-work your notes and drawings if they need it.

c. Assuming your handwriting is readable, keep the longhand version of your notes. See in your mind's eye the spatial layout of the notes; recall it as you would a photograph. Cursive handwriting and the hand drawings provide many visual and spatial cues that will facilitate

d. Come back later that same day for another rehearsal of what transpired in class, first by looking at your notes, then by not looking at them. Vocalize your notes; hearing the information will reinforce the retention especially for auditory learners. Repeat this review in each of the next several days.

Wednesday, January 16, 2008

Aerobic Exercises Increases Brain Volume in Elderly

As you get older, you will probably at some point start to worry about staying on top of your mental game. Will you get senile? Will you get Alzheimer's? These frightening questions may have a hopeful answer if you live a healthy lifestyle and get plenty of aerobic exercise.

A recent study by Arthur Kramer and colleagues at the University of Illinois used MRI brain scans to evaluate the effects of exercise in aged humans on parts of the brain that are most involved in age-related decline. They studied 59 healthy but sedentary volunteers, aged 60-79, during a 6-month exercise period. Half of the subjects participated in aerobic exercise, and the other half did toning and stretching exercises. Twenty young adults who did no exercise served as a control group. A before-and-after comparison of MRI images revealed that the aerobic group developed more brain volume, both in white- and grey-matter areas. These improvements did not occur in the young subjects nor in the older ones who did only muscle-toning exercise.

While memory as such was not tested, it is highly likely that increased brain volume could only help memory function.

Source: Colcombe, S. J. et al. 2006. Aerobic exercise training increases brain volume in aging humans. The Journals of Gerontology, Series A: Biological Sciences and medical Sciences. 61: 1166-1170.

Wednesday, January 09, 2008

Need to Learn Something Quickly? Try a Nap

Daytime naps are said to rejuvenate energy and lower stress. Now there is evidence that naps speed up consolidation of memories. Maria Korman and her group at the University of Haifa evaluated consolidation of a procedural memory task of learning to bring the thumb and finger together in a specific sequence. Half of the subjects were allowed to take an afternoon 90-min nap after training, while the other group stayed awake. The group that napped showed a distinct improvement in task performance when tested that evening. After a night's sleep, both groups showed the same improvement in acquired skill. So, it would appear that the nap just speeded up the consolidation process, rather than improving on the improvement that a regular night's sleep can produce.

The role of napping on interference effects was also tested. We know from numerous studies that consolidation of new learning is easily disrupted by distracting or other new learning experiences. In this experiment, another group of subjects learned a different thumb-to-finger movement sequence two hours after practicing the first task. Learning a second task right after the first was expected to interfere with learning of the first task. This proved to be the case; there was no improvement in performance of the first task either that evening or the next day after a normal night's sleep. However, based on the findings of the first experiment where a nap speeded up consolidation, the experimenters created yet another group of subjects that were allowed a 90-min nap between learning the first movement task and the second movement task. In this case, performance on the first task was improved when they were tested the next day after a normal night's sleep. Thus, the nap actually prevented the otherwise memory disrupting effect of a second learning task, presumably because the nap speeded up memory consolidation of the initial learning so that it was resistant to interference effects.

There are practical implications here, at least for procedural memories. This study indicates that if you need to learn a "how to" kind of task quickly, you should take a nap just afterward. One perhaps trivial illustration might be for football coaches who introduce some new training in the morning of a game to be played later that evening. After the morning workout, they should let the players take a nap that afternoon. Or for "two-a-days" workouts in the summer, maybe players need a nap between sessions, not just to rest but to consolidate the training.

Source: Korman, M. et al. 2007. Daytime sleep condenses the time course of motor memory consolidation. Nature Neuroscience. 10 (9): 1206-1213.