Saturday, December 19, 2009

"Catch Them Doing Something Right"

Savvy teachers use an operant conditioning technique known as “catch them doing something right.” It works for training seals and pony-and-dog shows in circuses-—why not kids? Well, it does work for kids. The idea is for the teacher to be more aware of what students do, and when students accidentally show some extra effort or accomplishment, they are immediately rewarded in some way. I don’t mean to trivialize the process, but it is not unlike when you are trying to house-break a puppy: when enough time has elapsed that urination is imminent, you take the pup outside. When it urinates, you pat him on the head and say “good dog.” After several such repetitions, the pup learns that the place to urinate is outdoors.

In a school environment, “doing something right” might be when a kid does a little extra on an assignment, or suddenly figures out a problem without prompting, or goes out of her way to make a useful comment in class discussion, etc.

How could this work for an individual? How can you catch yourself doing something right that you want to learn to repeat? First, be more aware of what you are doing. Self-awareness requires also introspection, so that you not only know what you are doing, but think about what is good for you and what attitudes and behaviors you want to develop (i.e., learn). The trick is to find ways to reward yourself when you accidentally do something new that is worth learning on a permanent basis.

For example, suppose you are trying to break a bad habit. You could note how long you can go without doing the habit. Then reward yourself. Using the idea I have described in my book about successive approximations, gradually raise the stakes so that you must go a little longer without a reward. The same idea applies to learning a new habit. When you do the thing you want, like smile more, or spend more time studying, or whatever--reward yourself. Then up the ante before reward.


Rewards can be most anything that pleases you. That is one of the best parts of this method. You get to pick your own reward. Maybe it is “time off for good behavior.” Maybe, you accept some indulgence, like cooking yourself a special meal, or taking yourself to the movies or a ballgame. For small successive approximation rewards, you might give yourself a small piece of candy, or some other treat. You can even create yourself a little “gold star” chart, like adults use with little kids, where you can see your progress in a very obvious way. After so many gold stars, you can give yourself a real treat. Silly? Yes, but it can work.

Sunday, December 13, 2009

Sleep Learning -- A New Perspective


A couple of decades ago, many people thought you could learn while you sleep. I remember as a college student playing audio tapes of information I wanted to learn while I slept. This idea turned out to be a fraud, perpetrated by people who sold sleep learning materials and equipment. Most "early adopters" found that all it did was disrupt sleep.

But as I have discussed elsewhere, modern research has compellingly shown that the brain is consolidating memories of the day's events during sleep. So, maybe the sleep learning idea is not completely dead. Maybe the right kind of stimulus input while you sleep could promote learning, at least in terms of promoting memory consolidation of the information you already learned during the day.

So, the idea would be to see if sleep can promote memory consolidation of things you recently learned, but have not yet formed into lasting memory. How might you do that? Since memory is largely associative, maybe it would work to provide during sleep the cues that were associated with the original learning. This might have a better chance of working during the dream stage of sleep, because it is well documented that external sound stimuli (like storms, rain, etc.) are documented as capable of becoming incorporated into and changing the course of a dream. Thus, the question becomes: can audio presentation of learned association cues during dreaming promote the memory formation for the original learning items or events. The idea is that the cue might reactivate a latent memory and thus constitute a memory rehearsal.

Partial testing of this idea has recently been reported. Northwestern University scientists trained human subjects to recognize the location of 50 different objects on a computer screen. Each object had an associated sound. For example, the cat image was associated with a meow sound, a kettle with a whistle, etc. Then people took a nap, during which sound cues were presented (unobstrusively at 62 decibels) for half of the images they had previously been exposed to. After the nap, subjects had no conscious recollection of the sound cueing.

The cues were presented oddly enough only during the deep stages of sleep, not during dreaming. Maybe the researchers were unaware that external stimuli can get incorporated into dreams. Even so, the original objects were re-presented after waking and subjects tested for recall of the location of the 50 images.

Measuring the location errors in terms of distance from correct position indicated that accuracy was greater for images that had associative cues presented during the nap than for those images for which cues were not re-presented. Simultaneous recording of brain waves (EEG) showed that the brain was responding to the sensory cues during sleep.

Tests in control subjects, who were tested without the intervening nap, showed that the cues provided no improvement in recall.

The principle seems sound. What remains is for clever entrepreneurs to develop memory-enhancing strategies that are specific for specific learning tasks.

The old ideas of sleep learning are dead, but here is a new opportunity for finding ways to get sleep to work for us. Learning protocols have to be developed for specific learning tasks, and these have to have relevant sound cues. Finally, I suspect that such external learning "reminders" will be more effective when presented during dream sleep, not the deep stage of sleep in which people "fall into a pit" of oblivion. The challenge is to find ways to provide appropriate reminders while we sleep (or dream).

Source: Rudoy, J. D. et al. 2009. Strengthening individual memories by reactivating them during sleep. Science. 326: 1079.

Friday, November 27, 2009

Kids Can Be Damaged by Excessive Cell-phone Use

As I have explained in my book, almost any activity that is interspersed between learning events, is an interference that can reduce learning efficiency. When children constantly interrupt study (even classroom work) by talking on their cell phones or text messaging, they reduce the efficacy of registering and remembering what they are supposed to learn. This often occurs in an environment of multi-tasking (listening to IPod or MP3 players, playing videogames, blogging, posting on MySpace or Facebook, etc.). These activities create a brain that has a short attention span and difficulty in focusing.

Now comes new scientific evidence that cell phone use may actually change brain chemistry. Some scientists say that cellphone use does have a biological effect on the brain. A recent study at Örebro University in Sweden reported that physical changes occur in brain from the radiation emitted by cell phones. Cellphone use increases the amount of a protein called transthyretin, which is a carrier of thyroid hormones in serum and is part of the ceberospinal fluid that cushions and protects the brain. But the researchers did not comment if the change is good or bad for the brain. But in any case, this should give us pause.

Children are more likely to be affected by cell-phone radiation than adults. Children have much thinner skull bones and their brains have a lot more fluid, so their brain tissues would likely absorb much more radiation compared to an adult’s brain.

The Swedish study found that children and teenagers who were heavy cell phone users were indeed more likely to report health problems. These included headaches and impaired concentration. This impaired concentration may have a biological cause in addition to the poor habits of mind that develop from excessive multi-tasking.

Source: Adapted from materials provided by The Swedish Research Council, via AlphaGalileo.

Saturday, November 21, 2009

Music Stirs the Emotions. Emotions Stir the Memories

Numerous anecdotal reports are suggesting that stroke or dementia patients benefit from listening to music. For example, Everett Dixon, a 28-yearold stroke victim, apparently learned to walk and use his hands again from daily listening to the kind of music he liked. Ann Povodator, an 85 year-old Alzheimer's patient, perks up when she listens to her beloved opera and Yiddish songs; her daughter says "It seems to touch something deep within her."

Caregivers commonly report that stroke or dementia patients can recall and sing songs from long ago, even when most other memories are lost. Moreover, the music can help retrieve memories that were associated with the music, not just the music itself.

Formal music therapy programs are sprouting up. Best known is the non-profit Institute for Music and Neurologic Function, directed by Concetta M. Tomaino, who lives in Garrison, New York. The Institute claims that music can help premature infants gain weight, autistic children communicate, stroke patients re-gain speech and mobility, surgical patients alleviate pain, and psychiatric patients relieve anxiety and depression. The most effective music seems to be that which the patient experienced and liked in their youth. Few of these observations come from controlled studies that rule out the possibility that the improvement was going to occur anyway without the music. Nonetheless, there are apparently 5,000 certified music therapists in the U.S. (I have no idea how one gets certified as a "music therapist.")

I do believe that there is some scientific basis for some of the claims. I have discussed elsewhere how emotions help to consolidate experiences into long-term memories as well as to retrieve such memories. Some of the same brain areas that generate emotions are also the ones involved in forming memories. Moreover, when a person initially hears a song, there may be powerful associations of other events and situations. We all know that associations help create robust memories.

Many students like to listen to music while they study. I think my frenquent listening to jazz helped me memorize all the required stuff in veterinary school. Others claim that classical music aids study. I would point out that both jazz and classical music are instrumental. I am convinced that songs with lyrics would be counterproductive, for the linguistic content serves as a distraction and could easily distrupt memory consolidation processes.

As for recall of already formed memories, music, if it is music you have learned to love, will at a minimum improve your emotional state, particularly in relieving stress. This alone can facilitate memory retrieval. Depression, anxiety, and stress are well known inhibitors of both memory formation and memory retrieval. Being happy not only feels good, it is also good for memory.


Sources:

http://www.bethabe.org/music_institute55.html
Beck, Melinda. 2009. A key for unlocking memories. Wall St. Journal, Tuesday, Nov. 17, p. D1.

Monday, November 09, 2009

Daytime Naps Promote Skilled-movement Learning

Whether you are learning to play the piano or learning to throw a football to a fast-breaking receiver, the necessary muscle movements have to be memorized. Converting the memory of movements into long-lasting form takes several hours or more for the brain to "consolidate" the learned movements. This process can be disrupted by trying to learn a different movement during this vulnerable period. For example, consolidation of the memory for a few chords on the piano can be disrupted by trying to learn finger movements on a computer keyboard during this consolidation period.

Another feature of motor learning is that delayed gains in skill performance can occur after a latent period of several hours after an effective learning experience. This delayed performance gain depends on the first post-training night's sleep (I have explained the role of sleep on other kinds of memory in my book on improving memory.

Now comes a study that shows that daytime naps condense the time course of motor- memory consolidation. In the experiment, subjects learned a five-element finger-to-thumb opposition sequence with their non-dominant hand. Then the experimenters tested the effect of a post-training nap. Compared to no-nap controls, a 90-minute daytime nap immediately after training markedly reduced the susceptibility to post-training interference effects and produced a much earlier expression of delayed gains within 8 hours post training. Thus, both memory-enhancing effects were produced by the nap.

Would a shorter nap produce the same effect? We don't know. It wasn't tested. Another untested possibility is that the daytime nap might enhance the memory consolidation that is normally produced by a night's sleep after a motor learning experience, especially if the task is rehearsed that same day after the nap.

Source:

Korman, M. et al. 2009. Daytime sleep condenses the time course of motor memory consolidation. Nature Neuroscience. 10 (9): 1206-1213.

Thursday, October 29, 2009

Memory Peg Systems

Memory peg systems provide a systematic way to use visual image "pegs" with material you are trying to remember. Peg systems are used by all memory wizards who put on shows exhibiting their extraordinary memory ability. They are also used by Las Vegas "card counters."

The basic idea in these systems, typically called “peg” systems, is to have a set of pre-memorized mental image “pegs” on which you hang images of items that you need to remember. A popular version of this is a room system. The process begins with picturing in your mind a room where certain conspicuous objects are unchanging, both in type and location. Then you use images of these objects as pegs for making associations. Suppose, for example, you want to memorize a to-do list and the sequence in which things have to be done: send e-mail to boss, call your dentist office for an emergency appointment, have lunch with a client, send a check to the water company, and a host of other things that I won’t list to keep this from being tedious. You might then use your bedroom pegs this way: you enter the door, which has an image of your e-mail system, Then your turn left to see your dresser, which has dentures sitting conspicuously on the top. Then you see the lamp on the dresser, which was turned off but now switches on to reveal a lunch plate. Next you see your bookcase with your checkbook falling off the shelf into a bucket of water. You continue this peg-linking process as you mentally move around the room from object to object and the mental images you need to associate with them.

You can use any room in your house, as long as the anchor pegs don’t change (such as furniture that you move periodically). You can also use other familiar rooms (garage, office, church, restaurant. I describe this and other peg systems, including a system for remembering numbers, in my book.

I recently came across a peg system by Dean Vaughn that I like. His system uses an imaginary numbered room system. This relies on an image of a cube, representing an empty room. Locations in the room are identified by number, beginning at one corner and moving around the room (wall to corner to next wall, etc.). Including the top and bottom of the cube, this gives peg anchor locations for 10 items. And if you need more than 10 items, you can create other rooms for 11-19, 20-21, etc.

You can start numbering at any point as long as you are consistent. I like to start with the wall facing me as point #1, because this is the center of the overall image. Here is an example of how I used this system this week to memorize a speech about writing as a career: to an English club at Blinn College in Brenham, Texas. After creating my mental images, I had them all memorized after about two to three rehearsals, and gave a 45 minute talk without notes and without even my hard copy of the numbered cube--not bad for somebody my age.

Here is how I did it: I made a numbered-cube template and saved it to use any time I want to develop a talk. Then for a given talk, I load the template in PowerPoint and read in appropriate icons to act as pegs. For example, my writing talk was on the subject “The Who, What, Where, Why, When, and How of Writing.” Icons are picked on the basis of what comes to my mind when I think of the word. For example, “who” makes me think of a hoot owl; “how” makes me think of an Indian. Many of the icons are sound-a-likes, or “audionyms.” For example, for “what,” I picked “hat,” for “where” I picked “hair,” for “when,” I picked hen.

For each topic icon, I write beside or underneath it in pencil a few key words and create mental images to represent the ideas associated with those key words. When I rehearse, if I can't recall all the images for a given peg, I look at the key words and reinforce the image or make one that will work better for me.

As the talk's preface, I decided to talk about my writing life, which I represented with the icon of a person (me) typing. Then I attached associated mental images (not real ones put on the template) to that icon (my high school, my college newspaper, a sample of my research papers, and a sample of my books). Next in the talk, I wanted to cover the topic of who do you write for. First, I discuss that a true writer writes because he must, that is he writes for himself. So I picture the owl looking at me. Then, I cover the theme that writers should know their audience and market, so I imagined the owl rotating its head as owls do to look away from me to look at a crowd of people. Well, I could go on with elaborations to the point of tedium. I assume you get the drift. The basic idea is to use images that make sense to you and associate them with your pegs.

Source: Vaughn, D. 2007. How to Remember Anything. St. Martin’s Griffin, New York.

Thursday, October 15, 2009

Multi-tasking May Damage the Brain

We older adults tend to be awed at how young people today can multi-task. They seem to text message on cells phones, watch TV, listen to music, play a video or computer game, carrying on a conversation, and maybe even study their school lessons all simultaneously with apparent ease. Many adults, and even teachers, encourage multi-tasking because they think it is good stimulus for the brain and that learning how to multi-task is a useful skill. But I have already identified many research reports that show multi-tasking to impair formation of memory. Multi-tasking prevents the focused attention and reduction of distractions that are necessary for good memory.

Now there is a research report suggesting that the brain itself may be damaged by multi-tasking. Investigators at Stanford University gave questionnaires to their subjects to identify how much multi-tasking each person did. Nineteen subjects were "heavy multi-taskers" and 22 were "light multi-taskers." Comparison of how these two groups in thinking control tasks revealed that heavy media multi-taskers were more susceptible to interference from irrelevant environmental stimuli and from irrelevant representations in memory.In other words, they were more distractible. Then researchers tested the subjects for ability to filter relevant information from the environment and from their memories and to switch thinking tasks. A typical filtering test, for example, required subjects to detect changes in red triangles on a screen while ignoring blue triangles in the same pictures.

The heavy multi-taskers performed worse, even though their experience and presumed skill at multi-tasking should have made them more effective at these tasks. The heavy multi-taskers believed that they were good at multi-tasking, when in fact they were bad at every task that required multi-tasking.

It is not clear how much physical deterioration has occurred in brain from chronic multi-tasking. But at a minimum, multi-tasking is likely to reduce the brain's ability to develop concentration and thinking skills. Why do I suggest diminished thinking skills? Thinking is done with an orderly progression of items in working memory. Multi-tasking bombards working memory with scrambled and unfocused information and probably keeps the brain from learning how to optimize focus and orderly sequencing of thoughts through what I call the brain's "thought engine."

Source: Ophir, E., Nass, C. and Wagner, A. D. 2009. Cognitive control in media multitaskers. Procedings of the National Academy of Science. Aug. 24. doi: 10.1073/pnas0903620106

Monday, October 12, 2009

Stress and Competence


When challenge exceeds competence we get stressed. As stress increases, our ability to overcome challenges decreases--creating a vicious cycle. How can we deal with this reality? Two approaches are obvious: we can either reduce the challenge or increase our competence.

The college students I deal with confront this dilemma regularly. Their response follows predictable patterns. They can lessen the challenge in several ways: reduce the demands on their time from social activities or other commitments. They can plan better what courses to take, when to take them, and how many credit hours they take in any one semester. They often fail to account, however, for the reality that many employers and graduate/professional school admission decision makers put major emphasis on a student's ability to handle large course loads of difficult courses.

So, it would seem prudent to emphasize development of competence. Students, for example, should study harder and study smarter. They should aim to remember important ideas and skills long after the test, so they can grow their competence base for use in later courses and in a career. Stress will then go down and success will go up. Now the cycle changes from vicious to positive.

Monday, October 05, 2009

Making Mistakes Over and Over

I was always told to learn from my mistakes. Actually, I found it was more efficient (and less painful) to learn from the mistakes of others.

Anyway, learning from mistakes, your own or those of others, is called "adaptive learning" in which decisions are made in anticipation of expected consequences. Habitual responses don't satisfy this definition because they occur indepently of the consequences. In fact, repeating bad choices and behaviors is a common personal and social problem. Why do we do that?

A new research report shows that stress may be the culprit by causing a bias in decision-making strategies. Chronically stressed rats diminished their ability to make decisions based on expected consequences. After a standardized chronic stress procedure, rats were tested to see if there was any change in their ability to perform actions based on consequences of their behavior. In one experiment, control, non-stressed rats trained to press a lever for a particular reward drastically reduced their lever pressing when the basis for rewards was changed to eliminate a clear relation of lever pressing to delivery of reward. When the same contingency changes were made with the stressed group, the rats resorted to a habitual response pattern. A second test was given to a second group of rats in which one action (pressing the left lever) would yield a reward (food pellet) and another action (pressing the right lever) would lead to a different kind of reward (sucrose solution). Responses in both normal and stressed rats showed progressive learning gains with repeated training. Then on the last day of training one of the lever press action conditions was changed so that the lever did not have to be pressed to get a reward. Rats in control group quickly reduced their press rate on the lever that did not have to be pressed to get reward. But stressed rats pressed both levers the same, showing they were making choices out of habit rather adapting to the changed situation.

Stressed rats showed structural changes in the cerebral cortex, which would predict that dysfunctional decision capability may be impaired for a long time.

Thus, it appears that chronic stress created dysfunctional decision making in rats. Is chronic stress the reason that some people continue to make one bad choice after another? If so, their bad choices often have their own bad consequences that add to the stress. It sounds like a vicious circle to me. Maybe there is also a role for stress in "learned helplessness," which I have written about in my book. That is, when you fail at something, the failure itself is stressful. Too frequent failure leads to chronic stress, which in turn impairs your ability to learn from your mistakes and continue to make bad choices.

Source: Dias-Ferreira, E. et al. 2009. Chronic stress cause frontostriatal reorganiztion and affects decision-making. Science 325: 621-625.

Thursday, September 24, 2009

Remembering the Bad Along With the Good

In my Sept. 15, blog I surveyed an experiment that showed people learning more from their successes than from their failures. In so doing, I raised the possibility that the learning gain was promoted by the release of the "reward transmitter," dopamine. Now I find a new research report on the effect of dopamine on the long-term storage of bad memories. The process studied was the long-term memory of fear and pain. Rats were trained to remember a strong foot shock, which lasted at least 14 days. Injecting a dopamine blocker into the hippocampus erased the long-term memory if given 12 hours after the original foot-shock experience. This suggests that the normal release of dopamine can promote memory, which is not surprising since dopamine promotes the formation of proteins used in synaptic junctions of neurons.

However, foot shock is certainly not rewarding and probably does not release dopamine. But the end of the foot shock pain is a rewarding relief. Also, rewarding things do happen even to rats after a nasty foot shock (like sex with mates, eating, drinking, sleeping, etc.). The ongoing release of dopamine in the course of just living may help rats form lasting memories, regardless of the nature of memory. This raises questions that scientists have not studied yet. But it may be that dopamine helps us remember both the good and the bad. And maybe is one reason why bad memories are hard to erase.

Source: Rossato, J. et al. 2009. Dopamine controls persistence of long-term memory storage. Science. 325: 1017-1020.

Tuesday, September 15, 2009

Why The Rich Get Richer

... (and the Smart Get Smarter)

This old saying also has a corollary: the poor get poorer (at least relative to the rich). Of course there are exceptions, but these correlations happen often enough to indicate there is some truth to the saying. I never heard anybody explain this, other than to conclude that life is just unfair. But there is an explanation.


The reason is that the rich learn from their successes, while the poor, who don’t have many successes, fail to learn from their failures. And the reason for that is that the human brain is wired to learn better from success than from failure. It all has to do with the positive reward system in the brain. Practically speaking, the most obvious example is how animals are trained for circus performances, how dogs are trained to sniff out drugs or corpses, and the like. Positive reinforcement when they do things right promotes learning more effectively and faster than punishing them when they do things wrong. Apparently, the same principle holds for people.

A report of a study of nerve cell activity in monkeys showed sustained, persistent outcome-related responses in both prefrontal cortex and in the basal ganglia, areas known to participate in learning stimulus-response associations. These neurons keep track of successes and failures over many seconds, which is long enough to form a semi-permanent memory that can affect the response the next time such a learning opportunity arises. The neural response improves after a recent success, but doesn’t improve as much after a recent failure. Not surprisingly, monkeys that were rewarded for the right resonse to a cue learned quickly how to respond the next time they saw the cue. But monkeys that responded incorrectly weren’t any better able to deal with the same cue the next time they saw it.


The authors speculate that successes are more informative than failures. When you fail, you typically already know why and there is not much new to learn. Why then do we keep making the same mistakes? I suspect that habit and emotional factors have a lot to do with it. Compulsive gambling and drug abuse are classic examples of repeatedly doing what you already know is wrong. I remember when I tried many times to quit smoking I only succeeded long term when I took up jogging, which is accompanied by the positive reinforcement of endorphins.


I also suspect that a major reason you learn more from success than from failure is the power of the brain’s dopaminergic and endorphin reward systems. Not only does positive reinforcement feel better emotionally than punishment, there is a real possibility that the dopamine release associated with reward has a direct biological influence on memory formation.

Source:
Histed, M. H., Pasupathy, A., and Miller, E. K. 2009. Learning substrates in the primate prefrontal cortex and striatum: sustained activity related to successful actions. Neuron. 63 (2): 244-253.

Motivation Comes In First

Laura, of "Dr. Laura" fame posted in her blog an item about how some students are paid money for doing well in school. Her blog referred to a Fox News item about a school district that was using financial rewards to motivate students to get good grades. ... Why would MONEY make the difference, and not the appreciation of their parents, the respect of their peers, the approval from their teachers, or the mere burst of pride in doing well? The answer is simple: kids these days are not raised to care about appreciation, respect, approval and pride…period! They are brought up to care about celebrity, extravagance, notoriety, freakish attention (think reality shows), infamy as a positive experience, and extreme non-conformity to traditional values. What happens to these kids when the money isn’t there, but there is still the expectation of profound effort and commitment? Certainly teachers, police, firefighters, those in the military, and small shop owners (to name just a few) aren’t putting out their best efforts for the financial reward. A police officer who “collars” a serious bad guy gets a lot of thumps on the back, a night of some beers with fellow colleagues, and a notch toward an eventual promotion in rank. Mostly, he has pride in doing his job well. ... Schools have been eliminating accolades such as high honors at graduation (e.g., valedictorian) so as not to hurt the self-esteem of those who won’t or can’t rise to that occasion. Yet, they want to give money, money, money to those who do. What is THAT message? No one’s feelings are going to be hurt because they didn’t get the money, money, money. Ugh."

I say "Ugh" too. At the heart of the school problem is that so many kids do not take pride in their work. How do you suppose that translates when they get out of school and on the job? I would argue that the most valuable lesson one can learn in school is to take pride in one's work. This story reminds us all that when it comes to learning, motivation may not be everything, but it is way ahead of whatever is in second place (which is probably poor memory skills). I have been teaching for almost 50 years, and I can tell you that positive motivation can overcome bad teachers, bad textbooks, boring subject matter, and almost any obstacle to learning you can think of. Conversely, no matter how hard a school or teacher may try to provide a good learning environment, good student performance is not going to happen without motivation. If people want to learn badly enough, they will surely find a way. True, a few academic subjects may be too advanced for a given level of IQ or pre-requisite learning. But even the slow of wit can learn a lot more than most people think. It may just take longer.

Source:Readin’, ‘Riting, and ….Bribing? June 11, 2009 on 10:32 am In Children, Education, Parenting, Values . Dr. Laura's Blog

Thursday, August 27, 2009

Naps Promote Learning of Movement Skills



Whether you are learning to play the piano or learning to throw a football to a fast-breaking receiver, the necessary muscle movements have to be memorized. Converting the memory of movements into long-lasting form takes several hours or more for the brain to "consolidate" the learned movements. This process can be interrupted by trying to learn a different movement during this vulnerable period. For example, consolidation of the memory for a few chords on the piano can be disrupted by trying to learn finger movements on a computer keyboard during this vulnerable period.

Another feature of motor learning is that delayed gains in skill performance can occur after a latent period of several hours after an effective learning experience. This delayed performance gain depends on the first post-training night's sleep (I have explained the role of sleep on other kinds of memory in my book on improving memory).

Now comes a study that shows that daytime naps condense the time course of motor memory consolidation. In the experiment, subjects learned a five-element finger-to-thumb opposition sequence with their non-dominant hand. Then the experimenters tested the effect of a post-training nap. Compared to no-nap controls, a 90-minute daytime nap immediately after training markedly reduced the susceptibility to post-training interference effects and produced a much earlier expression of delayed gains within 8 hours post training. Thus, both memory-enhancing effects were produced by the nap.

Would a shorter nap produce the same effect? We don't know. It wasn't tested. Another untested possibility is that the daytime nap might enhance the memory consolidation that is normally produced by a night's sleep after a motor learning experience, especially if the task is rehearsed that same day after the nap.

Source:

Korman, M. et al. 2009. Daytime sleep condenses the time course of motor memory consolidation. Nature Neuroscience. 10 (9): 1206-1213.

Monday, August 10, 2009

Here's Why Marijuana Impairs Memory Formation

Scientists have known for some time that marijuana impairs the ability to convert short-term or working memories into lasting form. Now they know why. The protein synthesis machinery in the hippocampus is necessary to accomplish lasting memory formation, and a study of mouse hippocampus revealed that marijuana impairs the protein synthesis pathway responsible for memory consolidation.

Source:
Puighermannal, E. et al. 2009. Cannabinoid modulation of hippocampal long-term memory is mediated by mTOR signaling. Nature Neuroscience. On-line edition, Aug. 2; doi:10.1038/nn.2369

Wednesday, August 05, 2009

Increasing Working Memory Makes Even Adults Smarter

I have pointed out a study in an earlier post a study that showed the IQ of children around age six can be increased by training them to increase their working memory capacity. This ability of working memory training to improve intelligence has now been demonstrated in young adults (mean age = 25.6 years). Subjects were trained on a so-called dual n-back test in which subjects were asked to recall a visual stimulus that they saw two, three or more stimulus presentations in the past. The task was dual in the sense that two stimuli were presented simultaneously for a half second, followed by a 2.5 second delay until the next stimulus. One stimulus type was a square in which another smaller square was shown in one of eight possible positions within the larger square. At the same time one of eight consonants were presented through headphones. A response was required every time one of the presented stimuli matched the one that had been presented n positions back in the sequence. As performance improved with each block of trials, the task demands were increased my shifting from two-back to three, then three to four, etc. Daily training took about 25 minutes.

Intelligence tests were periodically given that were based on visual analogy problems of increasing difficulty. Each problem presented a matrix of patterns in which one pattern was missing. The task was to select the missing pattern among a set of given response alternatives. This kind of testing measures what is called "fluid" intelligence, which refers to the ability to reason and solve new problems independently of previously acquired knowledge. What the investigators found was that working memory training improved scores on the intelligence test. Moreover, the effect was dose-dependent, in that intelligence scores increased in a steady straight-line fashion as the number of training sessions increased from 8 to 12 to 17 to 19. Working memory capacity presumably transfers to visual analogy tasks because you have to hold many visual features in working memory while you try to identify which pattern is missing in the matrix.

These results also challenge a widely held view that intelligence becomes fixed at a young age and cannot be increased by experience.

Source: Jaeggi, S. M. et al. 2008. Improving fluid intelligence with training on working memory. Proc. Natl. Acad. Science. www.pnas.org/cgi/doi/10.1073/pnas.0801268105

Friday, July 17, 2009

Txting Is Dangerous 4 U

"Dr. Laura" has written a very interesting blog item about text messaging on cell phones. She reminds us all of just how distracting texting is.

And when it comes to memorizing, texting is devastating for learning, unless of course you are texting about the content you are learning.

Monday, June 29, 2009

50 Tips to Improve Memory

One of the followers of this blog sent me a link to her blog that recently posted an article, "50 Ways to Make Your Memory More Like an Elephants" (http://www.onlineuniversities.com/blog/2009/06/50-ways-to-make-your-memory-more-like-an-elephants/).

The tips are not documented, but they do seem consistent with what I know about the research literature. Ten tips deal with diet, and these generally advocate foods that are high in omega 3s and antioxidants. Few of these have ever been shown to have memory-specific effects, but they all promote general health.

Another large batch of tips deal generally with lifestyle, but some ideas are not very profound, such as "don't get too drunk."

Five tips suggest ways to be more organized, such as using Evernote and using Google Calendar, both of which I find to be useful.

The list closes with some brain exercises. These are not memory specific, but they are good for the brain and thus good for memory.


Friday, June 19, 2009

Can Exercise Help Kids Do Better in School?

Even when I was a kid, people said that being physically active could help you perform better in school. But this was mostly anecdotal, with very little research evidence. Now there is some evidence.

Charles Hillman and colleagues at the University of Illinois recently reported a study on the effects of exercise on cognitive function of 20 preadolescent children aged 9 to 10. They administered some stimulus discrimination tests and academic tests for reading, spelling and math. On one day, students were tested following a 20-minute resting period; on another day, students walked on a treadmill before testing. The exercise consisted of 20 min of treadmill exercise at 60% of estimated maximum heart rate. Mental function was then tested once heart rate returned to within 10% of pre-exercise levels. Results indicated improved performance on the tests following aerobic exercise relative to the resting session. Recordings of brain responses to stimuli suggested that the difference was attributable to improved attentiveness after exercise.

Note that this is just from a single aerobic exercise experience. How can that be beneficial? The most obvious explanation is that exercise generates more blood supply to the brain, but I don't know that this has been documented with MRI studies, for example. Actually, what is known is that exercise diverts blood to the muscles. The generally accepted view is that the body tightly regulates blood flow to the brain and that the brain always gets what it needs. Another possibility is that exercise relieves anxiety and stress, which are known to disrupt attentiveness and learning. Maybe the repetitive discipline of exercises like treadmill walking help entrain the brain into a more attentive mode. We need a study that compares tradmill walking with a different kind of exercise regimen (like a vigorous and competitive basketball game, for example).

As for what goes on in a typical school recess, I doubt that such activities as shooting marbles, gossiping, or whatever else goes on these days with kids at recess, really helps school work. Gym class might be another matter, but unfortunately many schools do not provide a meaningful gym class. Some of the authors' suggestions don't seem to be supported by this particular research. For example, they advocate:

• scheduling outdoor recess as a part of each school day (recess does not typically provide aerobic levels of exercise)

• offering formal physical education 150 minutes per week at the elementary level, 225 minutes at the secondary level (again, the beneficial effects likely come from aerobic levels of exercise, not just any exercise)

• encouraging classroom teachers to integrate physical activity into learning (this almost certainly will not be at aerobic levels of exercise.)

There is the also the issue of a continuing aerobic exercise program, which presumably could produce long-lasting beneficial effects in young children. My own prejudice is that schools and parents ought to get serious about requiring an aerobic exercise program for kids. It should not only improve the quality of school work but also help combat the epidemic of obesity and diabetes. One caveat: running to achieve aerobic levels of exercise may not be advisable in children. My own experience with jogging, for example, might have been great for my heart and brain, but I now have two artificial kness to show for it.

If exercise is so good for academic performance, why do varsity athletes generally make poorer grades than their classmates? Well, there are many other factors, of course. One prevailing attitude among athletes is that academics are less important to them than their sport. Their peers idolize athletic stars. Students who make all As are not considered heroes; they are considered nerds or otherwise abnormal. Athletes devote their time and energy to their sport, not school work.

Reference:

Hillman, C. H., et al. 2009. The effect of acute treadmill walking on cognitive control and academic achievement in preadolescent children. Neuroscience. 31;159(3):1044-54.

Saturday, May 30, 2009

A New Treatment for Phobias and Emotional Trauma?

I have mentioned earlier the recent discovery that when a memory is recalled, it is then re-saved ("consolidated," as researchers llke to say). During that reconsolidation time window, which in rats is about 6 hours, the memory becomes vulnerable to new information and interference, and can become distorted or even abolished.

Researchers have discovered that injecting a beta blocker drug during this reconsolidation period can prevent re-consolidation of the memory that was recalled, and this is an effective therapy for some patients. The problem is that this is a prescription drug and is potentially toxic.

Another approach is to use extinction therapy. Most phobias and emotional traumas arise from a conditioned association between a neutral stimulus and the traumatic event, much like the conditioning discovered by Pavlov and his dogs. If one repeats the conditoning cue, without re-presenting the bad event, the patient may develop a new memory in which the cue becomes innocuous because it is no longer associated with the bad event. The problem here is that the effect can wear off over time, because the original fear memory was never erased.

A new approach has been devised by Marie Monfils, Joseph LeDoux, and colleagues at several neuroscience and psychiatric institutions. Their idea capitalizes on the differences between reconsolidation and extinction. They reasoned that if the non-threatening conditioning stimulus were given deuring the reconsolidation window, a new memory that the situation was safe would be formed. Use of a drug could be avoided.

They tested this idea in rats that were trained to be fearful by pairing a tone cue with electric shock to the feet.This was done three times. The intervention therapy consisted of testing for recall with the tone cue, followed by a series of extinction trials in which the cue was repeatedly delivered without accompanying foot shock. Some rat groups were given the intervention during the window and others outside it, like the next day. The behavioral response of fear was movement freezing. That is, when the tone was sounded, rats indicated their memory of the training by freezing out of fear.

The day after the extinction session, all groups showed a similar abolition of freeze behavior. Extinction worked, but did it last? A month later, the same rats were tested again, and the freeze behavior had returned in all rats except those that had received the neutral cue and extinction training during the reconsolidation window. Multiple other experiments supported the value of this intervention approach.

The investigators are now exploring clinical implications in human psychotherapy. There is a possible negative consequence. Erasing the phobia may be accompanied by the conditioning stimulus acquiring the status of being safe and not just neutral. Studies on humans can also allow experimenters to study not just the behavioral expression of fear but also allow them to examine the thought processes. The fear memory may still be there, with the major change being in the behavioral expression.

Source:
Monfils, M.-H. et al. 2009. Extinction-reconsolidation boundaries: key to persistent attentuation of fear memories. Science. 324: 951-955.

Saturday, May 16, 2009

There's a Reason for School Recess


Even when I was a kid, people said that being physically active could help you perform better in school. But this was mostly anecdotal, with very little research evidence. Now there is some evidence.

Charles Hillman and colleagues at the University of Illinois recently reported a study on the effects of exercise on cognitive function of 20 preadolescent children aged 9 to 10. They administered some stimulus discrimination tests and academic tests for reading, spelling and math. On one day, students were tested following a 20-minute resting period; on another day, students walked on a treadmill before testing. The exercise consisted of 20 min of treadmill exercise at 60% of estimated maximum heart rate. Mental function was then tested once heart rate returned to within 10% of pre-exercise levels. Results indicated improved performance on the tests following aerobic exercise relative to the resting session. Recordings of brain responses to stimuli suggested that the difference was attributable to improved attentiveness after exercise.

Note that this is just from a single aerobic exercise experience. How can that be beneficial? The most obvious explanation is that exercise generates more blood supply to the brain, but I don't know that this has been documented with MRI studies, for example. Actually, what is known is that exercise diverts blood to the muscles. The generally accepted view is that the body tightly regulates blood flow to the brain and that the brain always gets what it needs. Another possibility is that exercise relieves anxiety and stress, which are known to disrupt attentiveness and learning. Maybe the repetitive discipline of exercises like treadmill walking help entrain the brain into a more attentive mode. We need a study that compares tradmill walking with a different kind of exercise regimen (like a vigorous and competitive basketball game, for example).

As for what goes on in a typical school recess, I doubt that such activities as shooting marbles, gossiping, or whatever else goes on these days with kids at recess, really helps school work. Gym class might be another matter, but unfortunately many schools do not provide a meaningful gym class. Some of the authors' suggestions don't seem to be supported by this particular research. For example, they advocate:

• scheduling outdoor recess as a part of each school day (recess does not typically provide aerobic levels of exercise)

• offering formal physical education 150 minutes per week at the elementary level, 225 minutes at the secondary level (again, the beneficial effects likely come from aerobic levels of exercise, not just any exercise)

• encouraging classroom teachers to integrate physical activity into learning (this almost certainly will not be at aerobic levels of exercise.)

There is the also the issue of a continuing aerobic exercise program, which presumably could produce long-lasting beneficial effects in young children. My own prejudice is that schools and parents ought to get serious about requiring an aerobic exercise program for kids. It should not only improve the quality of school work but also help combat the epidemic of obesity and diabetes. One caveat: running to achieve aerobic levels of exercise may not be advisable in children. My own experience with jogging, for example, might have been great for my heart and brain, but I now have two artificial kness to show for it.

If exercise is so good for academic performance, why do varsity athletes generally make poorer grades than their classmates? Well, there are many other factors, of course. One prevailing attitude among athletes is that academics are less important to them than their sport. Their peers idolize athletic stars. Students who make all As are not considered heroes; they are considered nerds or otherwise abnormal. Athletes devote their time and energy to their sport, not school work.

Reference:

Hillman, C. H., et al. 2009. The effect of acute treadmill walking on cognitive control and academic achievement in preadolescent children. Neuroscience. 31;159(3):1044-54.

Wednesday, April 22, 2009

Three Ways to Slow Brain Aging


Moderate physical exercise, dietary restriction, and enriched environment stimulation are all known to be good for the brain in general and memory in particular. However, few studies have directly compared these three factors all in the same study, as has been done in the lab of Alois Strasser in the University of Veterinary Medicine in Austria. Moreover, Strasser examined also a brain chemical that is likely to cause some of the brain improvement, the so-called brain-derived neurotrophic factor (BNDF), which sustains neuron life and promotes growth of neuronal processes and synapse formation.


As brain ages, the levels of BNDF typically decline. Several studies have demonstrated that BNDF is important for memory function. Research prior to that of Strasser’s lab showed that exercise “up-regulates” BNDF; that is, exercise stimulates its production. And there had been some indication that environmental enrichment (stimulation, social interactions, etc.) had a similar effect. Therefore, Strasser and colleagues examined the tissue concentrations of BDNF in the cerebral cortex of old rats.

Rats were divided randomly into six groups, living from 5 months up to 23 months. In each age group, rats were divided into those that were given free access to running wheels (RW), forced running on treadmills, food restriction, and sedentary controls with no food restriction. Rats were either either housed individually or in groups of 4 to provide social enrichment. At the end of experiments, BDNF concentrations were determined.

Researchers found higher BNDF concentrations in the 5-month-old animals than in the 23-month-old-animals, suggesting that decline in BNDF accompanies old age and probably accounts for some of the mental decline. Within the older group of rats, sedentary rats that were housed in groups had significantly higher BNDF concentration compared to the old individually caged groups. Their BNDF concentrations were even higher than those of the young baseline group. The results suggest that housing and social interactions have more influence on BDNF concentrations in the cerebral cortex of aging rats than do physical exercise and food restriction.
There was some benefit of the exercise, but only from forced running on the treadmill, not voluntary activity. However, other studies had established that even voluntary exercise by old animals increased BNDF in other parts of brain, including the area so crucial to memory formation, the hippocampus.

The lack of beneficial effect of caloric restriction in sedentary rats to weight levels matching those of the voluntary exercise group was somewhat unexpected. Prior studies in other labs had shown that such restriction does promote synaptic plasticity and even birth of new neurons. Thus, there are no doubt multiple influences that can be beneficial to brain that are not mediated by BNDF. So, to the extent that these results can be extrapolated to aging humans, it would seem like a good idea to:
  1. Exercise regularly and vigorously (assuming you don’t have heart trouble or other conditions that would prevent it)
  2. Lose weight
  3. Get out of the house and socialize.
Source:

Strasser, A. et al. 2006. The impact of environment in comparison with moderate physical exercise and dietary restriction on BNDF in the cerebral parietotemporal cortex of aged Sprague-Dawley rats. Gerontology. 52: 377-381.

Increase Working Memory and Increase IQ

A key research report on working memory was summarized in a recent guest column in the New York Times by Sam Wang and Sandra Aamodt. Below is a summary of what they said in the article:

J. R. Flynn first noted that standardized intelligence quotient (I.Q.) scores were rising by three points per decade in many countries, and even faster in some countries like the Netherlands and Israel. For instance, in verbal and performance I.Q., an average Dutch 14-year-old in 1982 scored 20 points higher than the average person of the same age in his parents’ generation in 1952. These I.Q. increases over a single generation suggest that the environmental conditions for developing brains have become more favorable in some way.

What might be changing? One strong candidate is working memory, defined as the ability to hold information in mind while manipulating it to achieve a cognitive goal. Examples include remembering a clause while figuring out how it relates the rest of a sentence, or keeping track of the solutions you’ve already tried while solving a puzzle. Flynn has pointed out that modern times have increasingly rewarded complex and abstract reasoning. Differences in working memory capacity account for 50 to 70 percent of individual differences in fluid intelligence (abstract reasoning ability) in various meta-analyses, suggesting that it is one of the major building blocks of I.Q. (2-4). This idea is intriguing because working memory can be improved by training.

A common way to measure working memory is called the "n-back" task. Presented with a sequential series of items, the person taking the test has to report when the current item is identical to the item that was presented a certain number (n) of items ago in the series. For example, the test taker might see a sequence of letters like

L K L R K H H N T T N X

presented one at a time. If the test is an easy 1-back task, she should press a button when she sees the second H and the second T. For a 3-back task, the right answers are K and N, since they are identical to items three places before them in the list. Most people find the 3-back condition to be challenging.

A recent paper reported (5) that training on a particularly fiendish version of the n-back task improves I.Q. scores. Instead of seeing a single series of items like the one above, test-takers saw two different sequences, one of single letters and one of spatial locations. They had to report n-back repetitions of both letters and locations, a task that required them to simultaneously keep track of both sequences. As the trainees got better, n was increased to make the task harder. If their performance dropped, the task was made easier until they recovered.

Each day, test-takers trained for 25 minutes. On the first day, the average participant could handle the 3-back condition. By the 19th day, average performance reached the 5-back level, and participants showed a four-point gain in their I.Q. scores.

The I.Q. improvement was larger in people who’d had more days of practice, suggesting that the effect was a direct result of training. People benefited across the board, regardless of their starting levels of working memory or I.Q. scores (though the results hint that those with lower I.Q.s may have shown larger gains). Simply practicing an I.Q. test can lead to some improvement on the test (6), but control subjects who took the same two I.Q. tests without training improved only slightly.

Since the gains accumulated over a period of weeks, training is likely to have drawn upon brain mechanisms for learning that can potentially outlast the training. But this is not certain. If continual practice is necessary to maintain I.Q. gains, then this finding looks like a laboratory curiosity. But if the gains last for months (or longer), working memory training may become as popular as and more effective than games like sudoku among people who worry about maintaining their cognitive abilities.

Now, some caveats. The results, though tantalizing, are not perfect. It would have been better to give the control group some other training not related to working memory, to show that the hard work of training did not simply motivate the experimental group to try harder on the second I.Q. test. The researchers did not test whether working memory training improved problem-solving tasks of the type that might occur in real life. Finally, they did not explore how much improvement would be seen with further training.

Sources:

1. Flynn, J. R. 1987. Massive IQ gains in 14 nations: What IQ tests really measure. Psych. Bull. 101 (2) 171-191.

2. P.L. Ackerman (1987) Individual differences in skill learning: An integration of psychometric and information processing perspectives. Psychological Bulletin 102:3–27.

3. M.J. Kane, D.Z. Hambrick, and A.R.A. Conway (2005) Working memory capacity and fluid intelligence are strongly related constructs: comment on Ackerman, Beier, and Boyle (2005). Psychological Bulletin 131:66–71.

4. H.-M. Süss, K. Oberauer, W.W. Wittmann, O. Wilhelm, and R. Schulze (2002) Working-memory capacity explains reasoning ability—and a little bit more. Intelligence 30:261–288.

5. S.M. Jaeggi, M. Buschkuehl, J. Jonides, and W.J. Perrig (2008) Improving fluid intelligence with training on working memory. Proceedings of the National Academy of Sciences USA 105:6829-6833.

6. D.A. Bors, F. Vigneau (2003) The effect of practice on Raven’s Advanced Progressive Matrices. Learning and Individual Differences 13:291–312.

Monday, April 20, 2009

Visual Memory Has Astounding Capacity


My book on memory improvement presents much anecdotal evidence that people with outstanding memories use mental images of what they are trying to remember. Now, a formal scientific study validates the conclusion that ordinary humans have astounding memory capacity for visual (but not auditory) memories.

In this study, young adults (20-35 yrs) were shown a succession of object images, one every three seconds. They were told to remember as much as they could. After about each block of about 300 images, they were given a 5-minute rest break. After 10 such blocks (total images seen = 2,500; total time about 5.5 hours), they were tested with probe images and asked for each one if it had been seen before. Probe object images were paired in three ways: objects that were in a different category, the same category, or the same object but in a different state or pose. Performance accuracy was remarkably high for all conditions, respectively 92%, 88%, and 87% accuracy. Remembering 2,500 images with this level of recongition accuracy is truly astounding.

As comparison, a related study by another research group showed that auditory memory was markedly inferior. When subjects listened to sound clips (conversation, animal sounds, music, etc.) and then asked to distinguish new from old clips, under all conditions performance was systematically inferior to visual-memory performance.

Apparently, everyone has a degree of photographic memory. Certainly, the odds of recognizing that you have seen something are very high, at least under conditions where the image is a simple object. The storage capacity is huge. Does this apply to complex images that contain multiple details? Who knows for sure? The details can serve as useful cues or could even become confusing distractors. It is also not clear, if the visual-image capacity is limited to recognition or whether it applies to generating a recall without an image probe.

Even so, it is a good bet that memory performance will be optimized if memory items are converted to mental images.


Sources:
Brady, T. F. 2009. Visual long-term memoryh has a massive storage capacity for object details. Proc. Natl. Acad. Sci. USA. 106: 6008-6010.

Cohen, M. A. et al. 2009. Auditory recognition memory is inferior to visual recognition memory. Proc. Natl. Acad. Sci. USA. 106 (14): 6008-6010.

Thursday, March 19, 2009

Do Our Schools Teach "Cognitive Tools?"

In this age of high-stakes testing, schools focus on telling students WHAT to learn. How well do they teach students HOW to learn? ... not very well in my experience both as a middle-school curriculum developer and as a university science professor. I ran across a review of a new book entitled "The Future of Education. Re-imagining Our Schools from the Ground Up." The book apparently focuses on three goals of education: 1) socialization, 2) mastery of information, and 3) promotion of mental development. The book's author emphasizes a need to re-orient these goals around teaching "cognitive tools." Neuroscience is expected to reveal what those tools are, and it is the job of the school to teach those cognitive tools. Have schools even identified a set of cognitive tools? I know they don't explicitly appear in the national science standards. Communication between neuroscientists and school teachers is limited--they live in two different worlds. Moreover, the educational culture is not amenable to major change, especially one that requires teachers to re-orient their basic approach to teaching.

An example that I have mentioned before is the need to teach students how to memorize more effectively, using for example, the principles in my book. Few teachers teach memorization skills, and many have a prejudice against doing so. Also, it is increasingly clear that teaching students to increase the span of their working memory will raise student IQ and problem-solving skills. Yet I know of no school system or teacher that does that. Memorization skills are not tested on standardized tests and therefore are not taught. Real reform is a long way off. Many politicians and teachers think the solution for school reform is more money. Wrong!

Source: Egan, K. 2008. The Future of Education. Reimagining Our Schools from the Ground Up. Yale University Press. New Have, Ct. 203 p.

Monday, March 02, 2009

The Ethics of Drug Enhancers of Memory

Few people would argue against using drugs like Aricept to help Alzheimer's patients. Few would complain about using propranolol to assist in treatment of post-traumatic stress syndrome. But what about using memory-enhancing drugs for normal people?

For now, the question is moot, because there are no drugs that have been proven to help normal people. But such drugs are on the horizon. Several drug companies are working on such drugs. One drug was recently discovered in animals to have a positive side effect of improving memory. The drug, Fasudil, increases blood flow in the brain of rats and has potential for treating stroke in humans. This drug has now been found by Matthew Huentelman, an investigator at the non-profit Translational Genomics Research Institute in Phoenix, Arizona. to affect a gene that promotes memory, and when tested in 18-month old (middle-aged) rats, enabled the rats to perform better in water-maze learning and memory tests. The older rats performed as well as young rats. I don't know if this work is published yet (it is widely reported in the lay press), and it certainly has not been replicated.

But for the sake of argument, let us assume that it is correct. Are there ethical issues for normal people taking it to improve their memory, to get better performance at work, or for students to get better grades? Some students already take Ritalin or amphetamines to improve their performance. Is this like doping in sports? Or will we come to accept use of such drugs as preventive medicine, forestalling or preventing dementia, Alzheimers's or even normal mental decline with age?

Saturday, February 28, 2009

Erasing Fear Memories


I have discussed elsewhere a new idea for treating unpleasant memories, such as post-traumatic stress syndrome. The latest treatment being investigated by some researchers is based on using a common blood pressure drug, propranolol, which has a side effect of blocking the re-consolidation of emotions associated with old memories when those memories are recalled.

The original idea was first confirmed in rats. Now a study indicates that the approach can work in humans and might become a clinically valuable treatment. In this human study, subjects were given a mild shock when shown pictures of spiders on the first day of the study. Their fear response was measured as the eyeblink startle reflex to a loud noise. On day 2 of the study, the memory reactivation phase, the study volunteers exhibited the same response to the fearful stimuli (the spider pictures) as on day 1. On day 3, 20 of the subjects were given 40 mg of propranolol, and the remaining 20 were given a placebo. Next, the entire group was exposed to the fearful stimuli. The propranolol group did not exhibit the same startle response as on previous days. The placebo group showed no change in startle response compared to days 1 or 2. In other words, the drug reduced the emotional response, yet did not reduced the memory of the learned event.

Thus, it seems that if propranolol is in the body at the time when one recalls a bad memory, the emotional impact of the memory can diminish without impairing the ability to remember the item. Psychiatric treatment protocols remain to be worked out. Notice that in this situation the learned fear response was recent. Nobody knows if this effect occurs with old, well-entrenched fear memories. Another issue that nobody seems to be asking is the possibility that people on this kind of blood pressure medication might be suffering impairments of emotional memories that they don't want to lose. Does this drug cause a general dulling of emotions?

Source:

Merel Kindt, Marieke Soeter, Bram Vervliet (2009). Beyond extinction: erasing human fear responses and preventing the return of fear Nature Neuroscience DOI: 10.1038/nn.2271

Wednesday, February 25, 2009

Training Working Memory May Be Rewarding


Biological reward comes from the release of the neurotransmitter, dopamine. Performing working memory tasks promotes dopamine release. In the study of human subjects by Fiona McNab and colleagues in Stockholm, human males (age 20-28) were trained on working memory tasks with a difficulty level close to their individual capacity limit for 35 minutes per day for 5 weeks. After such training, all subjects showed increased working memory capacity. Functional MRI scans also showed that the memory training increased the cerebral cortex density of dopamine D1 receptors, the receptor subtype that mediates feelings of euphoria and reward.

Students who make good grades feel good about their success. Likewise, people who are "life-long learners" have discovered that learning lots of new things makes them feel good. Though this present study did not rigorously test the idea, it is possible that learning how to improve your working memory capacity can also make you feel good.

Source: McNab, F. et al. 2009. Changes in cortical dopamine D1 receptor binding associated with cognitive training. Science. 323: 800-802.

Wednesday, February 11, 2009

Eat Your Blueberries - But Not With Cereal.


I have reported earlier on a study indicating that blueberries are good for memory. Actually, there are several studies indicating that blueberries are good for mental function in general. Blueberries contain polyphenolics, the levels of which are indicated by the amount of two compounds, ferulic acid and caffeic acid. Ferulic acid helps to stabilize cell walls and protects the nervous system. It lowers blood pressure. Caffeic acid also protects neurons and may even prevent neural degeneration. Both compounds are powerful antioxidants.

Blueberries are potent anti-inflammatory agents. One study in rats fed a diet including a non-steroidal anti-inflammatory drug or a 2% blueberry diet showed that within just two weeks the blueberry supplement activated anti-inflammatory genes in the brain much more than did the anti-inflammatory drug.

Now, a recent report indicates that the health benefits of blueberries are blocked by milk. Phenolics have a high affinity for protein, and the binding to milk protein prevents phenolics from accessing body cells. The study that demonstrated this effect involved measuring blood levels of the blueberry phenolics at various times after human volunteers consumed 200 gms of blueberries with 200 ml of either water or milk. Levels of phenolics rose sharply when water was consumed, but there was no increase when milk was consumed.

Heat destroys blueberry phenolics. So even though blueberry pie tastes great, it won't help your health. Only fresh blueberries provide useful levels of phenolics.

So, the recommendation is to consume blueberries without proteins. It should suffice to eat blueberries either one hour before eating other foods or two hours afterwards. For me, I will eat my blueberries alone an hour before my milk and cereal.

Sources:

Serafini, M. et al. 2009. Antioxidant activity of blueberry fruit is impaired by association with milk. Free Radical Biology and Medicine. doi:10.1016/j.freeradbiomed.2008.11.023

Shukitt-Hale, B. et al. 2008. Blueberry polyphenols attenuate kainic acid-induced decrements in cognition and alter inflammatory gene expression in rat hippocampus. Nutr. Neuroscience. 11 (4): 172-182.

Friday, January 23, 2009

The Love Hormone and Memory for Faces


When you see an attractive face, a warm glow may ensue. When you see an ugly or threatening face, just the opposite occurs. Studies in animals have made it clear that a hormone from the pituitary gland, oxytocin, modulates such responses. In animals, oxytocin helps them decide whether to shun another animal or to approach for such purposes as socialization and mating. Oxytocin promotes approach behavior and suppresses avoidance.


If the same processes occur in humans (we use oxytocin too), then it should be reflected in how we react emotionally to others. Well, it does, and that is why it is sometimes called the “love hormone.” The best documentation for such action is that oxytocin is released in great amounts when a mother gives birth and increases the mother-infant bond. How robust this effect is in people is not clear.


Oxytocin could be important for remembering other people. In an experiment in Switzerland, men received a single nasal-spray dose of oxytocin and tested for their ability to recognize previously seen faces. The hormone improved recall of faces seen the day before, but had no effect on remembering non-social objects such as houses, landscapes, or sculptures. The study involved 44 male volunteers who were given three puffs of spray in each nostril of either oxytocin or a placebo. After a 40-minute delay to let the drug reach the brain, subjects were shown photos of 84 faces (half male, half female; 1/3 emotionally positive, 1/3 emotionally negative, and 1/3 neutral) and 84 images of inanimate objects for 3.5 seconds each. One day later, they were shown the same 84 pictures mixed randomly with other pictures they had not seen and asked to identify which photos they remembered and which were new from the previous day.


During the initial exposure (encoding) no differences were found in ratings for approachability (likeability) of either the faces or inanimate objects. Likewise, no oxytocin-related differences were seen for the emotional subcategories of positive, negative, or neutral, although everyone had more difficulty in remembering emotionally neutral faces. Gender of the faces did not seem to make much difference. Maybe this lack of effect was due to insufficient dosage (a single spray of three puffs may not be enough).


Where the drug effect was evident was in recognition memory of the faces. Oxytocin also increased the ability to realize that a new face had not been in the initial encoding group on the learning day.


Other studies have shown that oxytocin has a general pro-social effect, such as trust, for example.Take home message? One thought is the next time you want to attract someone, you might make yourself more memorable if you offered them some nasal spray laced with oxytocin. Of course that is too socially awkward. But one thing that is more practical is to take a few snorts of spray before going to a meeting or conference where you need to remember the new people you meet. Novartis already makes such a spray (Syntocinon). However, the drug’s medical use is to induce labor in pregnant women.


My second thought is there may something to the old saying about “love at first sight.” Certain faces may, for unknown reasons, cause a surge in endogenous secretion of oxytocin in the brain of the viewer and thus give that face a greater impact. Women knew all along the importance of having a memorable face; that’s why they wear makeup and fuss over their hair.


Source:

Rimmele, U. et al. 2009. Oxytocin makes a face in memory familiar. J. Neuroscience. 29 (1): 38-42.

Wednesday, January 14, 2009

Talking Makes It Memorable

Students learn better when they can discuss test items with their peers. A group of professors at University of Colorado, Boulder, reported a study in which they tested the value of allowing peer discussion of questions during lecture. To break up the monotony of traditional lecture in a genetics course, the lecture was periodically interrupted with a paired set of similar multiple-choice questions (Q1 and Q2) for any given concept was asked back to back. For each question, each student voted for the correct answer with a "clicker," and tallies of votes were automatically posted on the instructors podium computer. After the vote on Q1, students were allowed to discuss possible answers (without being told what the right answer was) and then allowed to vote again. Then, they were asked a second question on the same concept (Q2) and voted without discussion.

Performance results were markedly enhanced on the second vote on Q1. For example, pooled over 16 sets of questions, the average correct response to Q1 without discussion was 52%. But 92% got the question right after they were allowed to discuss it with peers (usually 3-4 classmates). Of this same group, 90% then got Q2 right.

Gains were also seen in the group the gave the wrong vote the first time they saw Q1 (48%). Of these, 42% got the answer correct after they discussed it with peers and 77% got Q2 right. Of those who missed Q1, even after discussion, 44% got Q2 right. This indicates that the understanding gained from discussing Q1 helped them with Q2.

The advantage seen here of discussion is primarily one of improved understanding, not necessarily improved memory. But memory should also be improved because peer discussion engages students in thinking, and thinking promotes consolidation. The sound feedback from talking also reinforces memory. Students recognized a memory benefit, as exemplified in the comment "the answer almost sticks better (italics mine) because we talked through it instead of just hearing the answer." What I would like to have seen is a controlled study of two classes, one that got their lecture interrupted with questions in this way and another class that did not, with a final exam given to both groups in which half the questions were the same as those used in class and half that were new but related.

Source:

Smith, M. K. et al. 2009. Why peer discussion improves student performance on in-class concept questions. Science. 323: 122-124.

Friday, January 02, 2009

Caffeine or Nap: Which Helps Memory?


Caffeine gets our brain pumped up. We are more alert and perhaps should remember things better. Naps have recently been found to help the memory consolidation process. Until now, nobody has made a direct comparison of these two factors in the same people under identical conditions. But Sara Mednick and her colleagues at the University of California, San Diego, now report some helpful findings.
They tested caffeine in a single dose of 200 mg (roughly equivalent to 2-3 cups of coffee) and compared with an episode of napping (60-90 min) or placebo on the effects on performance on three types of memory tasks. For verbal memory, they tested recall and recognition memory of word lists 7 hours after learning, with an intervening nap, caffeine dose, or placebo. In addition, they conducted memory tests for a finger tap and texture discrimination task.They also conducted short-term memory on a different set of words after the first experiment.
Compared with either caffeine or placebo, naps were more effective in the word recall test, both in the consolidation test and in the short-term memory condition. Caffeine actually impaired word recall in the short-term memory task, even though the caffeine had been given some seven hours earlier. Naps also improved recognition memory in the consolidation test and recall of the texture discrimination learning. For the finger-tap learning, naps were ineffective and caffeine markedly impaired performance. The caffeine group did feel less sleepy in the late afternoon immediately prior to the memory testing, but that did not help their memory performance.
What I take from this is that the morning coffee may help you awaken, but don’t count on it to improve your memory. Other research does show that caffeine enhances mood and alertness, reaction times and speed, but don’t count on it to help your memory for things you learn that day. Note to students: all-night study sessions are a bad idea for lots of reasons and probably made much worse by drinking lots of coffee. Note to bosses: letting workers take an afternoon snooze might be a good idea.

Source:
Mednick, S. C. et al. 2008. Comparing the benefits of caffeine, naps, and placebo on verb al, motor and perceptual memory. Behavioural Brain Research. 193: 79-86.