Landmark Research: Why We Need to Get Enough Sleep

In other blog posts I have explained why sleep is good for the brain in general and memory formation in particular. Now a new discovery provides another reason for people to get enough sleep. The study examined a type of support cell in the brain, oligodendrocytes–let’s call them oligos for short. These cells wrap their membranes around nerve cells to form what is called myelin, which forms an electrical insulation in a way that speeds up the propagation of nerve impulses through neural networks. You may have heard about oligos in reading about multiple sclerosis, a disease that impairs nerve communication because oligos die and the myelin insulation degrades.

Speed of transmission is important–it influences IQ for example. As you know from buying a new computer, the faster processor speed gives it new capabilities your old clunker could not do. A similar idea applies to the brain.

Anyway, this new study, from the University of Wisconsin, focused on oligos because other research had shown that sleep promoted the expression of several genes that are involved in synthesis of cell membranes in general and those in oligos in particular. Unlike neurons, oligos die, and are replaced in the brain. Thus, anything that affects their turnover is important for brain function. Sleep has been implicated in this turnover because a common neurotransmitter in the brain, glutamate, is known to increase in wakefulness and decline during sleep. Glutamate  suppresses maturation of oligo precursor cells into formation of myelin insulation.

In this particular study, investigators examined a genome-wide profile of oligo gene expression in mice after a 6-7 hour periods of sleep or spontaneous wakefulness, or four hours of forced wakefulness (sleep deprivation). They found that 357 genes were expressed differently, depending on the time of day, in response to normal daily rhythms. More dramatic was the observation that 714 genes changed expression in conjunction with the sleep/wakefulness cycle, independent of the time of day. Of these genes, 310 were “sleep” genes that were selectively activated during sleep.

Many of the sleep genes contribute to maturation of oligos into myelin. In follow up experiments, mice were injected with a radiolabeled tag that marks the birth of new cells. Injection occurred eight hours before mice spent a long period of either of wakefulness or sleep. The number of newly born oligos was almost double in the sleep group compared to the wake group. More detailed analysis showed that this increase was specifically correlated with the amount of REM sleep (dream sleep in humans).

This REM effect may have particular importance in humans. Most REM sleep occurs in the early morning hours and only after substantial time has been spent in non-REM stages of sleep. Thus, cutting a night’s sleep short by getting up early may decrease the amount of REM time and thus the beneficial effects on oligo proliferation. So don’t feel guilty about “sleeping in” from time to time.

We might also think about how these findings could have special relevance to children, whose brains are incompletely myelinated. Getting children up early in the morning to start school at 8 AM may not be such a good idea. Until school districts get around to changing school hours, you might tell you kids about my learning and memory improvement e-book, Better Grades, Less Effort, available at Smashwords.com.

Source:

Bellesi, M., et al. (2013) Effects of sleep and wake on oligodendrocytes and their precursors. J. Neuroscience. 33 (36), 14288-14300.

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Brain Exercise Works

Most people now have been told that mental activity is good for the brain. I have even posted information that it can build “cognitive reserve” that can delay or reduce the symptoms of Alzheimer’s disease. Therefore, it would be no surprise if popularity increased for mentally stimulating games like crossword puzzles, Sudoko, bridge, dominoes, chess, and the like.

In addition to these traditional games, another form of mental stimulation is to learn mnemonic techniques, such as creating associations with mental images, acrostics, acronyms, the method of loci, mental imaging of peg-words, and the like, which I explain in my books, Memory Power 101 and Better Grades, Less Effort. While these techniques are task specific, mastering them can produce benefits that last beyond the time when you are using these mnemonics. For example, when I was in high school, I used to give memory demonstrations using a well-known image-word peg system. Even when I quit doing that, my general capacity for remembering remained better than before because my brain had been trained to be more agile and imaginative in generating images that I could use in making memory associations. My mind was also probably more disciplined.

The scientific basis for such claims is solid. Numerous research reports confirm that even older people can improve their memory skills with instruction and practice.[1] Even with traditional memory training, research has shown that by teaching people multiple strategies, the training benefit can be seen immediately, can endure for up to five years, and even transfer to everyday learning tasks.

The scientific explanation is straightforward. When the brain is challenged to solve problems and enhance memory capability, the neurons have to grow new contact points among neurons. This process requires new protein synthesis, growth of neuron terminals, and boosting of neurotransmitter systems. In other words, mental challenge changes the brain physically. Through training, you can sculpt a more alert, focused, and smarter brain.

As a result of this understanding, a host of mental training options have become available. The hype often seems to sound like snake oil, but some training programs are documentably effective. For example, we know from published research that I have described before that working memory capacity can be extended by formal training and that IQ increases as a result.

A new emphasis seems to be emerging to create training platforms that are cost effective, self-administered, flexible, and easily distributed to wide segments of population. CD, audiotape, and web-based approaches can reduce the need for trainers who work one-on-one or with small groups. The web-based training seems the most feasible, except for the current crop of elderly, many of whom do not use the Internet.

Effective training need not be specifically address memory. Non-specific mental stimulation can improve memory capability, because whatever affects the brain affects the brain’s ability to remember things. Especially promising are training programs that train people to be more attentive, to have more positive attitudes about their memory ability, reduce anxiety and stress, and require learners to apply memory techniques to everyday mental tasks.¹ When benefits from memory training persist after the training, researchers assume it is because the trainees are still using the techniques they have learned. Method-of-loci and peg-word systems are extremely powerful, but it is hard to get people to create new habits of thinking and memorization. Even so, memory training produces other lasting effects that benefit memory irrespective of the explicit use of techniques. One of these effects is actual re-wiring of the brain, which intense learning is known to produce.

Many sites on the Web focus on teaching people about mental fitness in general, which as I just said, has collateral benefit on memory capability. One site I recommend, and have posted to, is Sharp Brains (http://sharpbrains.com/). Among the better known Web training programs are Brainware Safari and Lumosity (I have no conflict of interest here). Using “brain fitness” as search words in Google or Bing will identify many other sites that I am not familiar with.

Recently, a new three-dimensional videogame system, “NeuroRacer” that reportedly works even for older adults has been developed at the University of California, San Francisco.[2] In this game, a user navigates a race car along a winding track and hits a button on a controller whenever a green circle appears, making the response as quickly as possible. This task forces concentration and trains the brain to switch operations rapidly and accurately.

In a recently published test of the NeuroRacer’s effects on older adults, people aged 60 to 85 were trained on the game for 12 hours, spread over a month. Without training, the researchers found a clear age-related decline in performance in the game. After training on the game, the seniors performed on the game better than untrained 20-year olds, and the benefit lasted at least six months.

Popular press reports and numerous blogs of this study have attributed the benefit to the value of multi-tasking. I contend that multi-tasking is harmful for memory and, moreover, that the benefit of NeuroRacer is not multi-tasking training as such but rather the training it provides for attentiveness and executive control.  It is perhaps not surprising that such good effects were seen in older folks. A typical problem in aging is a loss in ability to focus, and thus training that increases attentiveness would be likely to have conspicuously beneficial effects.

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[1]Rebok, G. W., Carlson, M. c., and Langaum, J. B. S. (2007). Training and maintaining memory abilities in health older adults: traditional and novel approaches. J. Gerontology. 62B (Special Issue): 53-61.

[2]Anguera, J. A. et al. (2013). Video game training enhances cognitive control in older adults. Nature 501: 97-101.

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Thinking Is the Best Way to Memorize

People frequently ask me “What’s the best way to improve my memory? (or … my child’s memory? … my elderly parent’s memory?). The answer most commonly given is to use memory aids, that is, mnemonic devices such as associating mental images of new information with images of already learned images that serve as pegs on which to hang new information. I explain these devices in great detail in both of my books, “Memory Power 101” and “Better Grades, Less Effort.”

Mnemonics are essential if you want to become a “memory athlete” and show off prodigious feats of memory. After you have used such mnemonics for a while, some of the benefit persists long after you quit using such mnemonics because the brain has been trained to be more facile and imaginative in making associations.

But for real-world practicality, it is hard to beat the usefulness of thinking about what you are trying to remember. Thinking unifies the essential elements of learning, which I view as follows:

Knowledge → Understanding → Creative Insight

When people try to acquire knowledge, they of course must remember it, which they usually attempt by mentally repeating it again and again. This rote process is the least effective way to remember. When you think about what you are trying to remember, your efforts to understand it actually constitute rehearsal in meaningful ways. Attempts to understand include associating and cross checking the new with your understanding of what you already know, thinking about what else might be relevant, reflecting on the merits of the new information, and self-examination of your level of understanding. Then, as understanding is gained, you become poised for creative insight, making application of the new information for your own needs and purposes. In the process, you might even think of things about the new information that others have not discerned. This process automatically creates mental associations that not only cement the new information in memory but also integrate it with all the things you already know as well as perhaps even generating ideas that nobody else has thought of.

The biological basis behind this thinking process of memory rehearsal is now being confirmed. The original basis of the idea comes from suggestion some 20 years ago that multiple areas of brain participate in formation of memory.[1]Thinking engages multiple areas of brain and, when performed on what you are trying to remember, strengthens the memory representation in the brain areas that are creating the engram.

Some recent support for multiple-area formation of memory includes a recent brain-scan study of male and female college students during consolidation of a recent fear-induced experience revealed increased activity in multiple brain areas (amygdala, parahippocampus, insula, thalamus, ventromedial prefrontal cortex, and anterior cingulate cortex) during a resting state lasting 10 minutes immediately after the conditioning.[2]“Rest” occurred immediately after responding to the fear-inducing stimulus and probably involved a process of reflection on the learning task or an equivalent subconscious process.

Decreased activity occurred in the striatum (caudate, putamen). This decrease may have occurred because this area of brain includes the positive reinforcement (reward) system, and fear conditioning is aversive, not rewarding.

I should add that the extensiveness of brain areas participating in thinking and its associated memory consolidation was surely under-estimated. MRI brain scans measure metabolism, which is not a direct index of the nerve impulse signaling required for processing learning events.

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[1]Squire, L. R. (1992) Declarative and non-declarative memory: multiple brain systems supporting learning and memory. J. Cognitive Neuroscience. 4 (3):232-243 Posted Online December 13, 2007.(doi:10.1162/jocn.1992.4.3.232)

[2]Feng, T., Feng. P., and Chen, Z. (2013). Altered resting-state brain activity at functional MRI during automatic memory consolidation of fear conditioning. Brain Res. 2013 Jul 26;1523:59-67. doi: 10.1016/j.brainres.2013.05.039

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Learning To Be Stressed

People are constantly exposed to stressful situations. These may be physical (like participating in marathons, being exposed to radiation, and, perhaps surprisingly, exposed to sedatives or anesthetics). But stress can also be mental, wherein we become anxious and worried over certain events, existing or anticipated. Whether physical or mental, stress activates a brain network involving most directly the hypothalamus, the pituitary gland, and the adrenal cortex to release stress hormones. Such hormones include several cortisone-like compounds called glucocorticoids, and the most prominent one in humans is cortisol.

Glucocorticoids have profound effects on both body and brain. Regulation of glucocorticoids is accomplished by the brain, and learning experiences have profound effects on this control system. Most of what was initially known about glucocorticoids was their effect on the body. I had the great thrill of visiting the pioneer in this field, Hans Selye, in his laboratory complex at the University of Montreal. He had a whole room full of medals, awards, and honorary doctorate diplomas. He won practically every research accolade there was, except the Nobel Prize, one of several grievous slights by the Nobel committee. Dr. Selye wrote an autobiography for my book, Discovery Processes in Modern Biology.

Effects on the Body

Selye’s research led him to formulate the widely accepted concept of the glucocorticoid system as accounting for a “General Adaptation Syndrome,” which basically explained how the brain and body respond to stress. He discovered that glucocorticoids are “Goldilocks” compounds. That is, a little doesn’t do much, a lot is damaging, and intermediate levels are “just right.”

A moderate amount of cortisol is what is normally released every morning before you awaken. By the way, this is the reason surgeons want to operate early in the morning. This release helps prepare the body for the day’s activities by mobilizing blood glucose, typically by breaking down fat and, if needed, protein stores. Glucose is especially important for the brain, which has huge demands for energy, and which can only burn glucose for energy. Neurons are energized and memory ability is enhanced. Another useful thing cortisol does is to reduce the release of cellular chemicals that cause inflammation.

However, the hormone also inhibits systems that channel resources for growth and reproduction, impairs bone formation, and inhibits the immune system. Basically, the idea is that glucocorticoids help brain and body to respond to temporary emergencies by assigning lower priority to other physiological needs.

The rub comes when stress is prolonged. Selye discovered that the beneficial adaptation to temporary stress cannot be sustained in chronic stress. The system becomes exhausted and control breaks down.[1]Under chronic stress, body muscle mass decreases because the system has been breaking down proteins in order to generate energy. Inflammation bathes cells in toxic chemicals. Infections increase because the immune system has been compromised. In obese people, glucocorticoid levels cumulatively increase in fat cells, increase fat deposits still further, and increase the likelihood of type 2 diabetes and cardiovascular disease.[2]

Effects on the Brain

In the case of brain, persistent high levels of glucocorticoid often causes depression. Memory ability is impaired. Brain degeneration and cognitive decline accelerate. Many neurons are actually killed. What I want to stress here is that chronic high levels of cortisone change the neural circuitry that regulates its release. In other words, the brain learns a new way of functioning if constantly bathed in high levels of cortisone.

Effects of Learning

Few people make the connection between glucocorticoid control and learning. The neuronal circuits that control hormone secretion learn from stressful experience, just as all neurons learn from whatever they experience. What neurons in the cortisol control circuit learn in chronic stress is that the usual controls can’t work any more.

A typical response to a repeated stress of a certain type (for example, constant quarrels with a spouse or repeated job failures) can be habituation. It’s like “tuning out.” Repeated exposure to the same stress teaches the neurons to stop responding as much as usual. Thus, there is less of the benefits that glucocorticoids provide.

At the same time, the hormone control system becomes hypersensitive to other stresses, especially unpredictable or especially severe stresses. The control system learns to over-react to everything other than the stress to which it has habituated. Now, the damaging effect of too much glucocorticoid becomes pervasive, both for body and brain.

Whether the brain learns stress-coping strategies depends on conscious over-ride of hyper-active responses to stress, because the neural system (the limbic system) that operates our emotions also regulates the glucocorticoid control system. We can not only reduce excessive glucocorticoid but also teach our brain better ways to deal with stress by doing the following:

·         Simplify and organize our life,

·         Do one thing at a time and finish it,

·         Find pleasure in the little things,

·         Learn to have a more positive attitude,

·         Laugh and be happy,

·         Suppress anxiety,

·         Be more rational and less emotional,

·         Develop supportive social relations,

·         Reduce exposure to stressors. 

For more on learning and memory in general, see Dr. Klemm’s new book, Memory Power 101, Skyhorsepublishing.com.

Photos courtesy of FreeDigitalPhotos.net, by Artur  84 and Ambro

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[1] Herman, James P. 2013. Neural control of chronic stress adaptation. Frontiers in Behavioral Neuroscience. August 8. Doi: 10.3389/fnbeh.2013.00061

[2] Vogelzangs N. et al. 2009. Late-life depression, cortisol, and the metabolic syndrome. Am J Geriatr Psychiatry. 2009 Aug;17(8):716-21. doi: 10.1097/JGP.0b013e3181aad5d7.

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Does Humor Make You Live Longer?

I just attended a “Laughter is Good Medicine” seminar put on by a local hospital. The speaker pointed to evidence showing that laughing has such good effects as:

·         Reduce blood pressure

·         Lower blood glucose

·         Dull pain

·         Alleviate stress and anxiety

·         Improve feeling of well being

and it even burns substantial calories.

I suspect humor also improves longevity, though I only have anecdotal and presumptive evidence for that. But the evidence seems hard to dismiss. Think about how long so many classic stand-up comedians of the

preceding generation lived.

Most of these comedians were actively performing right up to their last days. Here is a listing of comedians most people in my generation will recognize and their age when they finally died.

Bob Hope, 100

George Burns, 100

Phyllis Diller, 95

Milton Berle, 94

Henny Youngman, 92

Victor Borge, 91

Dick Van Dyke, 88 (still alive)

Jimmy Durante, 87

Jerry Lewis, 87 (still performing)

Bea Arthur, 87

Groucho Marx, 87

Jonathan Winters, 86

Jack Paar, 86

Red Skelton, 84

Bob Newhart, 84 (still performing)

Soupy Sales, 83

Rodney Dangerfield, 83

Mel Blanc, 81

Johnny Carson, 80

Jack Benny, 80

These comedians obviously had good memories, because even in their old age they could spout a steady stream of jokes from memory without a teleprompter. To have a good memory, you have to have a healthy brain, and a healthy brain often is healthy because the body is healthy. Healthy bodies live longer.

Let’s also remember that some of these people led a hard life, mostly on the road, in an era when people in general did not live that long.

One thing is for sure. Whether or not humor makes you live longer, it surely does make you live happier.

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Older People Make Better Decisions

In an earlier post, I reviewed research showing that seniors compensate for any loss of memory ability by having developed learning and memory schemas over the years. Such schemas are ingrained strategies and ways of efficient learning that improve with experience and age.

Now I have come across recent research that shows another age-developed skill: improved decision-making ability. Teenagers are notorious for poor decision-making. Of course that is inevitable, given that their brains are still developing and they have had relatively little life experience to show them what works and what doesn’t. Unfortunately, what doesn’t work often has more emotional appeal, and most of us at any age are more susceptible to our emotions than to cold, hard logic.

Seniors also are prone to poor decision-making if senility has set it. Unscrupulous people take advantage of such seniors because a brain that is deteriorating has a hard time making wise decisions.

In between teenage and senility is when the brain is at its peak for good decision making, especially improving as one gets older. Some Eastern cultures venerate their older people as generally being especially wise. After all, it you live long enough, and are still mentally healthy, you ought to make good decisions because you have a lifetime of experience to teach you what future choices are likely to work and which are not.

Much of that knowledge comes from learning from one’s mistakes. On the other hand, some people, especially the young, can’t seem to learn from their mistakes. In any case, the best strategy of all is to learn from somebody else’s mistakes so you don’t have to make them yourself.

Learning from your mistakes can be negative if you fret about it. Learning what you can to avoiding repeating a mistake is one thing, but dwelling on it erodes one’s confidence and sense of self worth. I can never forget the good advice I read recently from, of all people, T. Boone Pickens, who has lost and regained fortunes several times. He was quoted in an interview as saying that he was able to re-make his fortune on multiple occasions because he didn’t dwell on the failures. He credited that attitude to his Oklahoma State basketball coach, who told the team after each defeat, “Learn from your mistakes, but don’t dwell on them. Learn from what you did right and do more of that.”

A key reason seniors make better decisions is that they have a richer store of knowledge and experience. Any choice among alternative options is affected by how much information for each option the brain has to work on. When the brain is consciously trying to make a decision, this often means how much information the brain can hold in working memory. Working memory is notoriously low-capacity, so the key becomes remembering the sub-sets of information that are the most relevant to each option. People are more likely to remember items they value and to forget low-value items.[1]

It turns out, apparently, that older people are more likely to remember the most useful information and thus make better conclusions and decisions. The National Institute of Aging began funding decision-making research in 2010 at Stanford University’s Center on Longevity. Results of their research are showing how older people often make better decisions than younger people.[2]^,[3]

As one example, older people are more likely to make rational cost-benefit analyses. Older people are more likely to recognize when they have made a bad investment and walk away rather than throwing more good money after bad.

A key factor seems to be that older people are more selective about what they remember. For example, one study from the Stanford Center compared the ability of young and old people to remember a list of words. Not surprisingly, younger people remembered more words, but when words were assigned a number value, with some words being more valuable than others, older people were better at remembering high-value words and ignoring low-value words. It may be that older people selectively remember what is important, which could explain why they make better decisions.

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[1] Castel, A. D., Rhodes, M. G., McCabe, D. P., Soderstrom, N. C., Loaiza, V. M. (2012). The fate of being forgotten: Information that is initially forgotten is judged as less important. Quarterly Journal of Experimental Psychology, 65, 2281-2287.

[2] Samanez-Larkin, G.R., Wagner, A.D., Knutson, B. (2011) Expected value information improves financial risk taking across the adult life span. Social Cognitive and Affective Neuroscience, 6(2), 207–217

[3]Carr, Dawn (2013). Why older minds make better decisions. Forbes. http://www.forbes.com/sites/nextavenue/2013/04/29/why-older-minds-make-better-decisions/

For more good advice on improving learning and memory abilities, see Dr. Klemm’s new book, Memory Power 101, Skyhorse Publishing.

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Working Memory Executive Control

Do you consciously monitor your working memory? That’s the limited-capacity memory you use when looking up a phone number, for example. If you fail to keep the numbers actively in mind while dialing, you may have to look up the number again. In other words, do you check yourself to see if you are still paying attention to what is in your working memory? Is your mind wandering away from what you are trying to hold in working memory? The cure is to deploy your brain’s innate capacity for executive control over working memory.

For more complicated memory chores than dialing a phone number, are you consciously aware of updating what is in your working memory at a given moment with new information? Do you think about being able to recall information you have just received—as when you are reading? Or do you ever willfully suppress what is in your working memory—as for example, expunging an unpleasant thought.

These questions deal with how well you are consciously aware of the likelihood you can recall what you are experiencing. I suspect that most of us exert some conscious executive control over working memory, but not nearly as efficiently as we could or should. Does it matter? Well yes, because controlling what is in your working memory affects the ongoing thought processes that are using the information that is in working memory. Moreover, how well you monitor your working memory affects how well the information registers in your brain and how well it can become consolidated into a more lasting memory.

I explain the consolidation process and ways to enhance it in my book, Memory Power 101.

Executive control of memory is relatively new in memory research, but one group reports studies suggesting that such research will prove fruitful. A year or so ago, this group’s poster presentation at the Society of Neuroscience meeting intrigued me, and I am delighted that the work has now been formally published.

One of their experiments evaluated listeners’ ability to monitor their moment-to-moment working memory storage capacity as new information arrived. As they listened to recorded word lists, experimenters told the subjects to pause the input at the maximum point that would still allow them for perfect real-time memory recall. That is, they pressed a key to pause the input of words in the list at the latest point at which they believe they would have perfect recall. Interestingly, all subjects paused the recording consistent with their known working memory span, as had been determined in pre-experiment testing. In a follow-up experiment, experimenters reduced the sound volume of the word list so that more effort had to be exerted to perform the task. Under these conditions, subjects were much less accurate in matching their listening to their natural working memory capacity and thus their learning was not optimal.

Obviously, such results suggest that making tasks more difficult can degrade thinking and learning. Teachers and professors who speak softly or with foreign accents should take note. Whatever benefit accrues from the challenge to pay better attention under difficult situations is offset by limitations in working memory storage capacity. Examples of degrading influences in addition to sound volume in listening to information include:

Listening is made more difficult by:

·         Extraneous noise

·         Unfamiliar speech accents

·         Speaking too rapidly

·         Speaking too softly

·         Simultaneous presence of visual stimuli that conflict or distract

·         Irritating or distracting mannerisms of the speaker

Reading is made more difficult by:

·         Font and page design selection

·         Convoluted syntax, awkward sentence structure

·         Unfamiliar vocabulary

·         Distracting visuals

·         Wordiness, poor grammar

·         Poor reading technique (tracking with finger movements, random eye fixations, small fixation span (a few letters or one word at a time)

In all situations, an important factor is whether the listener or reader has control over the speed of information presentation. Thinking and learning are compromised if a person has no control over chunking of information input and matching the input to their working memory storage capacity.

Another factor, not considered in this study, is the likelihood that people differ significantly in conscious executive control capability. We know, for example, that some people can hold focus much better than others can, and this certainly affects their ability to optimize working memory storage of information input.

Can working memory executive control be trained? There are already effective training protocols for expanding working memory capacity (as in the number of items you can hold in working memory). I suspect that we will soon see training programs to enhance executive control of working memory.

To summarize, you can optimize thinking and learning by willfully controlling the ease and convenience of information input as well as by how well you have developed a habit of conscious executive control.

Source:

Amichetti, N. M., Stanley, R. S., White, A. G., and Wingfield, A. (2013). Monitoring the capacity of working memory: executive control and effects of listing effort. Mem. Cogn. DOI: 10.3758/s113421-013-0302=0

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