Saturday, December 15, 2007

Learning to Pay Attention


One of the things that sets professionals apart from amateurs is their ability to focus on their area of expertise. I mean that literally. For example, recent brain imaging studies of 20 non-musicians and 20 musical conductors showed that the brains of both groups diverted activity from visual areas of brain during listening tasks. Activity rose in auditory areas of brain as it fell in visual areas. But during the harder tasks, brain activity changes were less marked in the conductors. The conventional interpretation is that when the brain focuses, it becomes more active in the areas that are processing the subject of the focus. In well-trained subjects, such as conductors in this case, their brain doesn't have to work so hard to pay attention to music, so there is less need for the brain to be more active in the auditory areas. So what this suggests is that ability to focus is a learned capability that derives from an actual lasting change in brain.

In the experiment, subjects during the scan were asked to listen to two different musical tones palyed a few thousandths of a second apart and identify which was played first. The task was made harder for the conductors, to allow for the differences from non-musicians. During the task, brain activity increased in the auditory areas, while it decreased in visual areas. In other words, the brain seems to allocate processing resources to the part of the brain that needs it the most. As the task was made harder, non-musicians diverted more and more activity to the auditory region as they struggled to concentrate.

The leader of the study, Jonathan Burdette, said "This is like closing your eyes when you listen to music." That is, you can pay attention to the music better when you brain is not being distracted by visual stimuli. He went on to make this analogy: "Imagine the difference bewtween listening to someone talk in a quiet room and that same discussion in a noisy room - you don't see as much of what's going on in the noisy room."

Three conclusions for improving everyday memory come to my mind:

1. The more knowledgeable you become in a certain area, the easier it is to pay attention to salient information. That is, the more you know, the more you can know.This is a different twist on the old saying, "The rich get richer and the poor get poorer."

2. Focus, and the attendant remembering that focus enables, is affected by distracting stimuli. If you are trying to learn visual information (graphics or text), a noisy background of music will make remembering worse because your brain can't focus its resources where it belongs.

3. The more you know, the more you can know.


Source: Wake Forest University Baptist Medical Center (2007, November 6). Listen Up, Tune Out: Training And Experience Can Affect Brain

Saturday, October 20, 2007

Role of Memory in PTSD and Other Anxiety Disorders

You don't have to be a combat soldier to develop anxiety disorders such as post-traumatic stress disorder (PTSD). Any bad experience in ordinary daily living is a learning experience that can be remembered for a long time. Such learning has associated with it unpleasant emotional responses.Much of this maladaptive learning is conditioned. That is, sensory cues, sometimes not even recognized consciously, trigger recall of disturbing memories or even just the negative emotions that went with the bad event.

As I explained in my book's section on memory consolidation, the original learning could have been disrupted by other, non-threatening events and distractions. Unfortunately, bad experiences typically get rehearsed extensively immediately after learning and that enhances consolidation of the bad situation and the distressed emotional state at the time.

Anxiety disorders are among the most common mental health problems and are often treated with so-called extinction therapies. That is, therapy is geared toward unlearning our fears by deliberately re-living the disturbing event under safe conditions and thereby learning we can cope successfully. It is like the old idea of getting back on a horse after you fall off. But that is not a good analogy, because if you get back on a horse, you could fall off again - hardly reassuring.

Modern psychotherapy for phobias and PTSD often involves so-called "cognitive behavioral therapy (CBT)," which requires re-living the original bad event under reassuring conditions by talking about it and even writing about it. But this has to be done with re-assessment with conscious realization that the original negative emotions and fear are no longer applicable because the re-living is a simulation in a safe environment. The re-living must include dealing with the negative emotions in the light of reason. Wikipedia's description of CBT is that therapy requires "questioning and testing cognitions, assumptions, evaluations and beliefs that might be unhelpful and unrealistic; gradually facing activities which may have been avoided; and trying out new ways of behaving and reacting." Relaxation and distraction techniques are also commonly included. This re-creation of the bad event allows us to extinguish memory of the original bad situation and its negative emotions.

Extinction is something scientists know a lot about. I recently got an up-date in this area of research at a seminar by Gregory Quick from the Dept. of Psychiatry at the University of Puerto Rico. As Pavlov showed, extinction is a basic phenomenon even in simple animals. If you repeatedly ring a bell and then give foot shock to a rat, it soon learns to become distressed the next time it hears that bell, even if it does not get a shock. In the lab, this is manifest by the rat showing freeze behavior. But, if you repeat the bell enough times without foot shock,the conditioned response (CR)(freeze behavior) is extinguished. At first,scientists thought that memory of the CR is erased during extinction, but even Pavlov, the father of conditioned learning, recognized early on that extinction is a new learning experience. Think of it as learning to unlearn. Extinction creates a new memory that competes with memory of the original CR. Both memories co-exist. However, over time the extinction memory may be lost, and the CR can return. Presumably, the rules for effective consolidation apply to extinction learning as well as to CR learning. Therapy would be more effective if therapy for PTSD and other anxiety disorders was approached like a conventional learning experience whose memory needs considerable nurturing. The confirmation that extinction is new learning comes from experiments showing that traces of extinction memory remain after extinction learning seems to be forgotten. Re-learning of an extinguished response occurs much more readily than it does for an initial extinction learning.Its like re-learning a foreign language. It goes easier the second time.


Memory of a distressing event and memory of its extinction can co-exist. Which memory is retrieved determines whether or not anxiety results.

As this picture shows, memory of a CR and its extinction can co-exist. The practical consequence is that these memories compete for which one is strong enough to be retrieved. Sadly, the CR memory is often stronger. As I explain in my book, cues are extremely important to both forming and retrieving and memory. It seems likely that in typical human situations, there are many more cues in CR than in extinction. Therapy should be aimed at enriching the number and variety of cues associated with extinction learning.

Here is an example applied to humans that this kind of research suggests to me: if you are afraid of heights, it could be because some frightening event happened, perhaps years ago, that involved a high place. You may not even remember what caused the fear, but clearly any high place provides plenty of cues to trigger the memory of that conditioned memory. Now, if you progressively force yourself in small steps to go to high places, under clearly safe conditions, you can learn to extinguish this memory by thinking about how irrational your fear is. For instance, walking up a staircase should not evoke fear if there is no way you can fall off. These new extinction learning experiences need to be consciously attended, rehearsed, protected from interfering stimuli, and otherwise nurtured to promote consolidation. You should strive to construct all sorts of cues that can be associated with your extinction trials. These cues should strengthen the consolidation of your extinction learning and moreover, make the extinction memory more retrievable in the face of other cues that were associated with the original CR. Like any other memory, the extinction cues and environment need to be re-experienced often at periodic intervals so the extinction memory is strengthened at the expense of the original CR that created the anxiety disorder.

Source:

Quirk, G. J. et al. 2006. Prefrontal mechanisms in extinction of conditioned fear. Biological Psychiatry. 60: 337-343,

Wednesday, October 03, 2007

Benefits of Increasing Working Memory

In an earlier post, I summarized some Japanese research showing that working memory capacity can be increased in young children and that such increase even improves IQ. Accumulating evidence seems to indicate that working memory, with proper training, can be improved in anyone, even adults. Improved working memory results in improved attention (recall my other posts about how the main memory problem in aging is usually not memory per se but poor attentiveness), better reasoning ability, and better self control.

I recently found a paper in which lasting increases in brain function were produced in healthy adults by only 5 weeks of practice on three working-memory tasks that involved the location of objects in space. Subjects performed 90 trials per day on a training regimen (CogMed) and MRI scans showed increased activity in the cortical areas that were involved in processing the visual stimuli. Brain activity increases in these areas appeared within the first week and grew over time.

Similar results have been reported by other investigators. In a few cases, where different kinds of stimuli were used, memory training induced a decrease of brain activity in certain areas, which is interpreted to indicate that the trained brain did not have to work as hard.

While we clearly don’t understand things very well, it seems clear that working memory training not only improves memory capability but also causes lasting changes in the brain.

Reference:

Olesen, P. J., Westerberg, H., and Kingberg, T. 2004. Increased prefrontal and parietal activity after training of working memory. Nature Neuroscience. 7: 75-79.

Saturday, September 08, 2007

Losing Your Past

Do you remember the names of your elementary-school teachers? How about the name of the bully in middle school? Or names of your friends when you were a kid? These are all things you remembered well at one time and remembered for a long time. But you may well have forgotten by now.

Scientists like to talk about "long-term" memory, but even long-term memory has its limits. A recent study on rats suggests what it takes to sustain longer term memories. Rats in the study learned a "bait shyness" task. Rats were given a drink of saccharin-flavored water, and then shortly afterwards injected with lithium, which made them nauseated. This was a typical conditioned learning situation, as with Pavlov's dogs. In this case, rats typically remember to avoid such water for many weeks. This is the basis for "bait shyness." If rats survive a rat poisoning episode, they will avoid that bait in the future. However, in this experiment,one group of rats received an injection directly into the part of the brain that holds taste memories.This injection contained a drug that blocks a certain enzyme, a protein kinase. These rats lost their learned taste aversion. The bad memory was lost irrespective of when the injection was made during the 25 days after learning occurred.Giving the enzyme blocker before learning had no effect on the ability to learn to avoid the flavored water.The protein kinase thus seems to be necessary for sustaining a long-term memory. It is possible that other long-term memories the rats may have had were also wiped out by the enzyme-blocking drug, but this was not tested.


So what is the practical importance of these findings? I suggest that even "long-term" memories have to get rehearsed once and a while or they may eventually fail to remember (see my earlier post on "reconsolidation" of memories. Or if you do remember, there is a good chance that the memory is corrupted, that is, not totally correct. The consequence is that things that happened long ago may be either forgotten, misremembered, or so buried in memory that it takes a great deal of cuing to retrieve the memory. I have a whole chapter in my book, Thank You Brain for All You Remember on the subject of false memory.

The study showed that a certain enzyme has to be present to preserve a memory. Without the enzyme, the memory disappears. What sustains the enzyme? I suspect it is rehearsal and periodic reactivation of the memory, although this possibility has not been tested yet. Some scientists are excited about the possibility of developing a drug that would eliminate the enzyme or insure its presence. The problem with that, however, is that the drug could abolish old memories that you might not want to forget (like your name) or may cause you to remember too much that is now irrelevant.

Source:

Shema, R., Sacktor, T. C., and Dudai, Y. 2007. Rapid erasure of long-term memory associations in the cortex by an inhibitor of PKM. Science. 317:951-953.



For more summaries of recent research with practical application, click here.

Saturday, August 11, 2007

Students Who E-communicate Have Lower Grades


A new study of 517 California high-school students found that grades were lower in those who socially interacted over the Internet using MySpace, instant messaging (IM) accounts, or who used cell phones. In the study, students answered a questionnaire on what social networking devices they used and when they used them. The answers were paired with the grades (from the previous year and the most recent report card).

In this study, 72% of the students had a My Space account, 76% had a cell phone, and 68% had an IM address. Those who had a MySpace account had significantly lower grades than those without an account. The same was true for those that used IM, compared with those who did not. Cell phone use was also associated with lower grades and the effect was magnified if text messaging was used on cell phones. Not surprisingly, if these devices were used during homework, the grades were even lower than for students who used these technologies outside of homework. Almost half reported text messaging during class time, and their grades were lower than the students who only used IM outside of class.


These are correlational data and do not prove that using these devices causes lower grades. But it is a good bet. Multi-tasking, as when using the communication devices while trying to do homework or learn in class, is well-known to interfere with memory . Poor memory yields lower grades. See my other posts on multi-tasking.

Source:

Pierce, Tamyra, and Vaca, Roberto. 2007. Distracted: academic performance differences between teen users of MySpace and other communication technologies. Proceedings EISTA. Orlando, FL. July. http://www.cyber-inf.org/imsci2007/Program/html/program-5.htm

For more summaries of recent research with practical application, click here.

Saturday, July 07, 2007

New Neurons Die Unless You Save Them

A recent study in adult mice indicates that new neurons in the memory-forming part of the brain have only a narrow time window, about three weeks, in which they can be saved. How were the saved from death? ... by providing a stimulating environment. Rather than being raised in standard laboratory cages as were the controls, the test mice lived in groups in cages that had various toys and things to do. These neurons survived if they were born one-to-three weeks earlier, but not if the enriched environment was available later.The spared neurons survived throughout the four-month observation period.

People also presumably are birthing new neurons, but learning experiences and mental activity are probably needed to help these new neurons to get incorporated into existing circuitry. If new neurons don't get included in circuitry, they will die.

For more details, click here.
To get the big picture of how memory works and how to improve it, get the book. Click here.

Sunday, June 24, 2007

Multi-tasking: How the Brain Fools You

Are you impressed with the multi-tasking abilities of young people? Don't be. Our brain works hard to fool us into thinking it can do more than one thing at a time. It can't. Recent MRI studies at Vanderbilt prove that the brain is not built for good multi-tasking. When trying to do two things at once, the brain temporarily shuts down one task while trying to do the other. In their study, even doing something as simple as pressing a button when an image is flashed causes a delay in brain operation. It is highly likely, though not yet studied, that the delays and confusion magnify with increases in the number of different things one tries to do simultaneously.

For details on this research go to the Web supplement for my book on improving memory: thankyoubrain.com

Friday, June 08, 2007

Forgetting Can Be Good - Solving the "Tip-of-the-Tongue" Problem

Ever forget something you know you know ... like a friend's name or some other equally embarrassing piece of information? It is on the tip of your tongue, but you just can't get it out.

New research suggests that the problem is caused by a failure to forget. That is, you remember too many wrong things that interfere with the recall of what you want.

Researchers at Stanford University recently clarified this problem by a study in which subjects were required to recall words from among many similar words that they had also seen but not required to remember.

Recall effectiveness ranged from about 30 to 80%, with better performance correlating with poor recall of those words that subjects were not supposed to remember. In other words, the better subjects could forget irrelevant information, the better they could recall what they were supposed to remember.

During all of the testing, subjects had their brains scanned by MRI, and these results showed a decrease in brain activity in the brain areas that detect and resolve memory competition as a given word pair was rehearsed. That is, as the learning progressed, there is a decrease in the amount of work the brain has to do. Interestingly, with the irrelevant word pairs, the effectiveness at forgetting was associated with still greater decreases in brain activity. That is, forgetting of competing memories lowered the required workload for remembering the relevant memories.

Clearly, "tiip-of-the-tongue" recall problems would benefit from strategies that improve the ability to forget irrelevant memories. I am not aware of any formal studies that tell you how to do this. My own experience suggests two things to do, which I explain on my Web site.

Source: Kuhl, B. A. et al. 2007. Decreased demands on cognitive control reveal the neural processing benefits of forgetting. Nature Neuroscience. Published online: 3 June; | doi:10.1038/nn1918.
http://www.nature.com/neuro/journal/vaop/ncurrent/suppinfo/nn1918_S1.html

Read more about it at http://thankyoubrain.com/PracticalMemoryResearch.htm
... and get "Dr. Bill's" book from that site so you will have a complete background on how to improve your memory.

Tuesday, June 05, 2007

New Neurons. Use Them or Lose Them

Many studies have demonstrated that new neurons are continuously being born in the hippocampus, the part of the brain that forms new memories. Learning increases the survival of neurons born up to a week before the learning. In other words, use them or lose them.

Source: Drapeau, E. et al. 2007. Learning-induced survival of new neurons depends on the cognitive stateus of aged rats. J. Neuroscience. 27 (22): 6037-6044.

Read more about it at http://thankyoubrain.com/PracticalMemoryResearch.htm
... and get "Dr. Bill's" book from that site so you will have a complete background on how to improve your memory.

Epicatechin - Newly discovered memory Chemical

It is found in blueberries, tea, grapes, and cocoa, and it improves memory in laboratory animals. Epicatechin, is one of a family of chemicals known as flavonols. It improves blood flow in the brain and presumably also in the heart. In a recent study of maze learning in mice, memory lasted longer in the group that got the epicatechin supplement and also exercised. Memory also improved in the sedentary mice, but was not as pronounced.

Source:
van Praag, H. et al. 2007. Plant-derived flavanol (-) epicatechin enhances angiogenesis and retention of spatial memory in mice. J. Neuroscience. 27 (22) 5869-5878.

Read more about it at http://thankyoubrain.com/PracticalMemoryResearch.htm
... and get "Dr. Bill's" book from that site so you will have a complete background on how to improve your memory.

Thursday, April 26, 2007

Omega-3 Fatty Acid Supplements Improve Memory

Taken your omega 3 tablets today? A new study suggests that you need to get in the habit of taking omega-3 (specifically the omega-3 fatty acid, docosahexaenoic acid). Such supplementation benefited mice that were genetically engineered to produce the two different proteins that create the amyloid plaques and neurofibrillary tangles that characterize Alzheimer's disease in humans.

The study focused on testing the dietary ratio of omega-3 to another fatty acid, omega-6. People typically consume omega-3 from fish, eggs, and organ meats, while omega-6 is prominent in corn, peanut, and sunflower oils. It turns out that it is the ratio of the two fatty acids that is important, and the diet of most people does not have enough omega-3. A typical Western diet produces a ratio ranging from 1:10 to 1:30, where ideally it should be 1:5 to 1:3.

Previous mouse-model studies in other labs have shown some benefit from a variety of such dietary sources as green tea, fish, blueberries and from exercise and environmental enrichment.

Alzheimer's disease is a growing public-health problem as people live longer. Today, roughly 5% of the population over 65 has Alzheimer's disease, and as many as one half of the 80-year-olds have it. By 2050, predictions are that 20 million people in the U.S. will have Alzheimer's disease (it is 4.5 million now).

To learn more abut the actual experiment, go to my Web site on practical memory research.

Saturday, April 07, 2007

Learning to Learn

Ever wonder why some people can learn like sponges, soaking up information in great gobs, while others struggle to learn? It is akin to the rich getting richer, while the poor get poorer.

Well, scientists have discovered that good learners have learned how to learn. This is especially evident for specific areas of expertise, where an existing expertise makes it easier to become even more expert. This principle was recently rediscovered (actually it was discovered at least twice before, dating back to 1932). The idea is being framed in terms of “schema,” or pre-existing knowledge that makes it easier to make associations with new information. The experiments actually focused on how having a schema speeds up the consolidation process.

So what is the take-home message for people? Just this: learn, learn, learn. The more you learn, the more schemas you are developing, making it easier to learn even more. My guess is that this principle is especially useful for learning such things as a foreign language, music, or an academic discipline. This richness really will become richer.

To learn more abut the actual experiment, go to my Web site on practical memory research.

Friday, March 23, 2007

Folic Acid Improves Memory

In a recent study of 818 normal middle-aged people,folic acid supplement reduced cognitive decline in general and specifically improved memory ability. The dose used was double the Recommended Daily Amount (RDA).

Learn more about it at my Web site on improving memory. Click here and follow the link in the "Medical Issues" category.

Teenage Angst Is Bad for the Brain

Remember being a teenager? ... and all the stress of boy-girl problems, over-bearing parent problems, bullies, worries about school and your future, and frustrated attempts to be popular? Scientists have long known that chronic stress can kill nerve cells. Now it seems that an especially vulnerable time is adolescence. It now seems clear that the brain is being re-built during teenage.

Read all about it at my memory improvement Web site. Click here. Follow the link to the "Emotions" category.

Sunday, February 25, 2007

Remembering Names and Faces

Everybody has trouble remembering names and faces. The usual tricks don't always work, and may even be counter-productive. I have just posted a summary of a study that challenges the conventional approach to remembering names and faces. Click here for details.

More confirmation of sleep loss impairment of memory

I just wrote a summary of yet another study which showed that missing one night's sleep impairs memory of what happened the next day, even though the sleep loss was made up later. The test conditions involved losing sleep on one night, then learning stuff on the next day, followed by a normal night's sleep, and then being tested the next day. So this indicates that this is a "proactive" effect, where sleep loss before learning impairs learning. I have reviewed other studies that show impairment when sleep loss occurs at the same time as learning, as in cramming for exams. Click here for details.