Brain Gain
We have previously discussed how a relatively small number of strategies can dramatically reduce your risk of cognitive decline as you get older.
Our recommendations are firmly buttressed by a most important article available for free download at the website of the Journal of the American Medical Association.
We already knew that cognitive training can improve cognitive abilities in older adults but nobody had established the effects of cognitive training on everyday function.
Sherry Willis of Pennsylvania State University led a team of scientists that followed a group of 2,832 adults, aged 65 and older -mean age 73.6 years – who were still living independently between 1998 and 2004. The seniors came from all walks of life, races, and parts of the country, including Birmingham, Alabama; Detroit, Michigan; Boston, Massachusetts and three other major cities. They all had one thing in common when the study commenced: they had no signs of cognitive impairment.
The researchers divided them into four groups of roughly 700 each: three groups that would receive training in either memory (verbal episodic memory), inductive reasoning or speed of processing (visual search and identification) with 4-session booster training at 11 and 35 months after training, and one that would serve as a control.
The memory training program consisted of mnemonic strategies for remembering word lists or texts, such as associating various words, visualizing them or organizing them in specific ways. Reasoning training taught the participants how to spot the pattern in a series, such as “a c e g i… .” The researchers boosted the subjects’ processing speed via practice, practice, practice in identifying an object on a screen after increasingly short exposures.
Over the course of the next five years the researchers asked participants to appraise their skills and to report whether the training had helped with everyday tasks. They also independently evaluated the subjects’ skills in things like finding items in a medicine cabinet. After training, 87 percent of the speed trainees, 74 percent of the reason trainees and 26 percent of memory trainees showed immediate improvement. That advantage over their untrained peers persisted over the next five years.
The training seemed to largely offset the cognitive decline suffered by nearly all of the controls as the years wore on. By the fifth year, significant skill gaps had opened between the people who had done the training and their untrained peers.
It is not enough to continue to do the crossword or sudoku puzzles. The brain must be continually stretched and challenged. It seems that to drive this effect, you have to practice things that you don’t like or things you don’t regularly practice.
Many of us have spent years working on new training strategies, and this research shows just how valuable cognitive training can be for all of us.
A Memory for Faces
Your humble reporter has always had a good memory for faces. A month after a meeting in San Antonio at which we had about 250 attendees, he was in another part of the country when a charming man came over to say, “You won’t remember me, but I was at your lecture in Texas last month.”
He looked like a man who’d eaten a raw egg when he got the response, “Oh yes, fifth row from the back, fourth person along.”
It would be great if that memory for faces could be linked to a memory for names or something else useful. But sad to say it isn’t. Just the face, and when and where it was last seen.
But new research in neuroscience has shown us ways to tether other memories to each other.
So it was interesting to see a new report of some fascinating research from Vanderbilt University in Nashville suggesting that it is common for us to be better able to remember faces than other objects and in addition that faces “stick” the best in our short-term memory. The reason may be that our expertise in remembering faces allows us to package them better for memory, since faces are complex and their recognition is also essential for normal social relationships.
The findings are currently in press at the journal Psychonomic Bulletin and Review.
The key component of the research is visual short-term memory or VSTM has a unique way of being coded in the brain. The findings have practical implications for the way we use our memories. Clearly being able to store more faces in VSTM may be very useful in complex social situations. Just think for a moment how much most people like being remembered, particularly if you can attach a name and salient fact to the memory. Most of the successful business people and politicians that I know are remarkably adept at doing this.
Short-term memory is crucial to the way in which we create impressions and adapt to a continuously changing world. It serves as temporary storage for information that we are currently using: rather like the RAM on a computer. For example, in order to understand this sentence, your short-term memory will need to remember the words at the beginning while you read through to the end. People with some neurological and attentional problems have a real problem with doing that. VSTM is a component of short-term memory that helps us process and briefly remember images and objects, rather than words and sounds.
VSTM allows us to remember objects for a few seconds, but as with working memory and all the short-term memory stores, its capacity is limited. The new research focuses on whether we can store more faces than other objects in VSTM and the possible mechanisms underlying this advantage.
Study participants were asked to look at up to five faces on a screen for varying lengths of time (up to four seconds). A single face was later presented and the subjects had to decide if this face was part of the original display. For a comparison, the process was repeated with other objects, like watches or cars.
The researchers found that when participants studied the displays for only a brief amount of time (half a second), they could store fewer faces than objects in VSTM. They think that this is because faces are more complex than watches or cars and therefore they require more time to be encoded. Surprisingly, when participants were given more time to encode the images (four seconds), an advantage for faces over objects emerged.
The researchers believe that our past experience with learning faces explains this advantage. This theory is supported by the fact that the advantage was only observed if the faces were upright: the most familiar orientation. Faces that were shown – and therefore encoded – upside-down showed no advantage over other objects.
This is very similar to the situation in chess, where, compared with a novice, a master can instantly remember a position on the board if the pieces are in logical places. If they are arranged at random, the master does no better than the rank amateur.
Most of the textbooks tell us that the capacity of short-term memory is something is fixed, and that you either have a decent capacity or you do not. However the research indicates that you can learn to improve your capacity for this form of memory.
This makes sense: as a child your reporter rarely made notes and his parents supported him in that. More than one school teacher thought him lazy and inattentive because his note books consisted of doodles and random scribbles in between pages of homework.
How many other children have also been accused of cheating or faced punishment or ridicule simply because they had a good memory, but did not learn in the same way as the other kids?
We already have some methods for training people to get better at using visual memory, but most have been discovered by trial and error. This new research will make it that much easier to devise memory training methods rooted in brain science.
But also remember something else: sometimes forgetting is as important as remembering.
Elbert Hubbard, the American Editor, Publisher and Author who perished aboard the Lusitania in 1915, had this to say, “A retentive memory may be a good thing, but the ability to forget is the true token of greatness.”
Memory Molecules
There are still a great many mysteries about memory:
- The molecules in neurons are constantly changing, as are many of the connections between cells. So how can memory be maintained for a lifetime in an environment that is in a constant state of flux?
- Why is it that you can remove large regions of the brain yet memories are not lost? Even in the late stages of Alzheimer’s disease, some long-term memories are maintained even when much of the brain is taken over by plaques and tangles.
- How much memory is there outside the brain and in the body?
- Is some memory maintained not in the brain itself but in fields associated with the body?
Gradually some questions are being answered not just by technology, but by asking new questions and bringing new types of expertise to bear on these problems.
A very interesting new study was published last week in the Journal of Neuroscience. The paper was not by neurologists, but by two mathematicians from the Brain Institute at the University of Utah. Their research suggests that memories are held in our brains because certain proteins serve as anchors, holding other proteins in place to strengthen the connections between nerve cells known as synapses. The anchors keep proteins in place, and these proteins in turn determine how strong a synapse is. And the strength of the synapse is a key to forming and retaining memories.
Synapses function by electrical activity in a neuron releasing a chemical neurotransmitter that affects another neuron or an organ.
One of the primary neurotransmitters involved in learning and memory is called glutamate, that binds to a number of receptors. But the most important for memory are the "AMPA receptors" that are embedded in the receiving ends of neurons. The AMPA receptors are held in place by special scaffolding molecules.
The mathematicians were able to make several predictions about the way in which AMPA receptors stay in place and how repeatedly learning something strengthens the connections between neurons.
The key to learning and remembering is anchoring AMPA receptors on our neurons.
I went into the technical side a bit, because this finding may help us get closer to understanding what goes wrong in Alzheimer’s disease.
It also ties in with some other research out this week in the journal Neuron. A team from the Univesity of Oxford has been trying to work out why adults may find learning more difficult than children. The young learn things more easily, but older brains stiore information more efficiently. They also focused on synapses, and seem to have found the mechanisms involved.
Young brains have many "silent" synapses that don’t do anything unless called upon to learn something. Older brains have to reuse synapses that have already been used, boosting the strength of connections with increased amounts of neurotransmitters.
So as we get older, our brains adopt different strategies for learning new material, and we should get ever better at organizing and integrating information.
That also fits with the strategies that we have used for improving people’s ability to learn and remember. We use connections as in Mind mapping, multiple sensory associations inclusing music, color and smells, and a sophisticated method for asking constant questions to see if new information fits with material that we have already asimilated.
The Seat of the Emotions and the Gateway to Reason
“If passion drives, let reason hold the reins.”
–Benjamin Franklin (American Author, Inventor and Diplomat, 1706-1790)
For many centuries reason and emotion have usually been held to be two poles of a magnet, the North and South of the psyche. Every now and then someone has proposed some other psychological lodestone, but most have finally devolved into this simple binary model.
Yet a moment’s introspection shows us that reason and emotion are inextricably linked. We know from people with alexithymia and a dizzying array of “personality disorders,” that a real-life Mr. Spock would be a hobbled creature. Yet we also know that simple binary models of pleasure and pain as the drivers or behavior are over simplified. It appears that one of the great attainments of many mammalian species – and who knows how many others – is an ability to be moved by more complex considerations of loyalty, propriety and even morality.
There is an important study in this month’s issue of the Journal of Neuroscience. The amygdala is a central processing station in the brain for emotions and is involved in laying down emotional memories. A shock or extreme pleasure may both leave their traces in the amygdala, so it plays a key role in survival.
But this new research shows that the amygdala also plays a role in working memory, a higher cognitive function that is critical for reasoning and problem solving. If you ask someone for a telephone number and you instantly dial the number and then forget it, that is working memory in action. If you choose to remember the number for later, it moves out of working memory into longer term memory stores. In some senses working “memory” is a little bit of a misnomer: it is a function that enables us to manipulate information extremely rapidly.
In two different functional magnetic resonance imaging (fMRI) studies with a total of 74 participants, individual differences in amygdala activity predicted behavioral performance on a working memory task. The experimental subjects were asked to look either at words, such as rooster, elbow, and steel, or faces of attractive men and women. Then they were asked to indicate whether or not the current word or image matched the one they saw three frames earlier. Try it for yourself, and you will see that this is quite challenging. The subjects’ brains were scanned while completing the tasks.
People with stronger amygdala responses during the working memory task also had faster response times.
This is exceptionally important for anyone interested in thinking and learning: it shows that a region of the brain thought to be involved primarily, or perhaps even exclusively, in processing emotions is also involved in higher cognition, even when there is no emotional content.
I think it most likely that the amygdala may be involved in vigilance, perhaps preparing people to better cope with challenging situations and also improving their ability to sort information according to its relevance to the current situation. This is something that people with poor resilience find hard to do, so it may be that the amygdala is involved in developing and maintaining resilience.
This study helps to prove the total inter-relatedness of emotion and cognition and supports learning strategies that are based upon integrating emotion with facts. One of the ways in which health care students are able to remember enormous numbers of facts is by attaching them to patients with whom they have worked. Emotion, interest and empathy can dramatically accelerate learning.
Erasing Your Neurological Hard Drive
Did you ever see the movie Total Recall, and wondered if it might really be possible to erase someone’s memory and implant a new one? Well, that might just be a little closer than most people realize.
One of the mechanisms of the storage of memories in the brain is thought ot involve a process known as long-term potentiation (LTP), that strengthens synaptic connections between neurons. The mechanism of LTP has been a mystery, but recently it was discovered that there is a biochemical pathway that utliizes something called an atypical protein kinase C isoform, protein kinase Mzeta (PKMz), that seems to be a key player in LTP.
New research from a team at SUNY Downstate Medical Center, in Brooklyn, New York, using a PKMz inhibitor reverses LTP and produces persistent loss of 1-day-old spatial information, proving that PKMz is crucial to laying down memories in the brain.
There are many ways of losing memory. Apart from being belabored about the head and shoulders with a stout cudgel, alcohol and benzodiazepines are all fairly reliable ways of causing transient memory loss. But they also may fail, and each may have other unpleasant consequences.
But this is different: undestanding the basic mechanism of memory formation may enable us to obliterate unpleasant or wanwanted memories in conditions like chronic pain and posttraumatic stress disorder. It may also help us understand something more about the mysteries of illnesses like Alzheimer’s and Dementia of Lewy Body type, in which memory can be lost.
But it is also important to keep an eye on this research. I would not like either a government or a corporation to have a way reliably to erase our memories.
Though I’ve often thought that I’d quite like to have one of those little Neutralizers that they had in Men in Black…..
Body Posture and Memory
“Memory moderates prosperity, decreases adversity, controls youth and delights old age.” –Lactantius Firmianus (Roman Rhetorician often known as the "Christian Cicero,” A.D. 260-340)
The Ancients had many methods for remembering factual details: the best known were methods for associating memories with physical places, the columns in a theater, part of the body or body positions.
There a very interesting new study form Florida State University in Tallahassee that examined the impact on autobiographical memory of assuming the same (congruent) or different (incongruent) postures that the person held during the original event.
Response times were shorter when the subjects’ body positions during memory retrieval of were similar to the body positions in the original events than when the body position was incongruent. Free recall of the autobiographical events two weeks later was also better for congruent-posture than for incongruent-posture memories. This has theoretical implications for the idea of embodied cognition: that the environment plays a role in the formation of cognition, and perhaps also for the two other ideas:
1. That the body can hold memories and
2. Antonio Damasio’s concept of the "somatic marker mechanism" that may provide the neurological mechanism for a crucial psychological concept: theory of mind.
Theory of mind refers to our ability to understand that other people have minds that have desires, beliefs and intentions that are separate form our own. Some experts believe that an inability to fully form a theory of mind underlies some of the problems in autism and schizophrenia.
The fact that specific body postures can be used to improve autobiographic memory may also be one of the mechanisms by which mudras, or symbolic gestures may activate memories and their associated feelings and states of consciousness.
This research follows a study that indicated something that you might already have noticed: positive thoughts are more easily recalled in the upright posture. Slouching tends to make you feel negative and to generate and recall negative thoughts. You may also have noticed how you, or the people around you become more still when they are concentrating on something. Research has shown that when people are successfully engaged in complex cognitive tasks, the normal swaying of their bodies is reduced.
So what are we to make of all this?
If you are trying to recall something that happened to you, adopting the same sort of posture may help your recall. Conversely, some body work to stop you getting into that same position may perhaps lessen recall. And physical stillness may help you focus if you have to engage in a complex cognitive task.
“To a mind that is still, the whole universe surrenders.”
–Chuang Tzu (Chinese Philosopher, c.369-286 B.C.E.)
Neurotheology
Over the last three decades researchers at a number of universities have studied meditators and people in prayer, or experiencing mystical experiences, and tried to pinpoint the region of the brain responsible for these experiences. Some researchers went as far as to suggest that there’s a specific region of the brain that’s responsible for direct communication with God, while others have been far more skeptical. One of my early teachers was convinced that mystical experiences were simply forms of temporal lobe epilepsy. I was just as convinced that he was wrong. But back then I was the student, and he the master. So I was put firmly in my place. Neuropsychologist Michael Persinger and his group at Laurentian University in Canada has reported that he can very precise magnetic fields to artificially stimulate regions within the temporal lobes to induce a state of “sensed presence.”
A new study conducted by Mario Beauregard and Vincent Paquette from Montreal has just been published in the journal Neuroscience Letters.
The investigators used functional MRI (fMRI) scanning in 15 Carmelite nuns to try to examine the brain processes underlying the Unio Mystica: the Christian notion of mystical union with God. This is the latest episode in a field that is becoming known as neurotheology.
The nuns were asked to relive a mystical experience rather than actually trying to achieve one. Rather than reveal a spiritual center in the brain – a “God spot,” as the popular press called it – the researchers found a dozen different regions of the brain were activated during the recall of the mystical experience. The experience was mediated by brain systems and regions that are normally implicated in emotion, self-awareness and body representation.
It is important to note that despite the title of the study – “Neural correlates of a mystical experience in Carmelite nuns” – this was actually an experiment on memory, and there were some technical objections to the study. There is a fine critique here.
There is also a point that I have brought up before: can we really try to reduce complex psychological and spiritual experiences to a groups or systems of neurons? My own view is that we are seeing necessary neurological correlates of an experience, but that these measurements tell us nothing at all about the key aspects of what the nuns remember: the sense of meaning, value and purpose that flow from the mystical experience.
Memory and Anticipation
“Nothing is so wretched or foolish as to anticipate misfortunes. What madness is it to be expecting evil before it comes.”
–Lucius Annaeus Seneca (a.k.a. Seneca the Younger, Spanish-born Roman Philosopher and Statesman, c.4 B.C.E.-A.D. 65)
We are all aware that memories of powerful and in particular disturbing emotional events – such as an act of violence or the unexpected death of a loved one – are more vivid and deeply imprinted in the brain than mundane recollections of everyday matters. When I was sixteen years old I was in a head-on car crash: I can still recall the number of the license plates of the car that was driving down the wrong side of the road as it barreled into us. But particularly positive emotions are also remembered in far more vivid detail, and those memories are less likely to be lost. This all makes good sense from an evolutionary perspective: we need to be able to remember things that carry a strong emotional charge.
Colleagues at the University of Wisconsin in Madison have found that the mere anticipation of a fearful situation can activate two memory-forming regions of the brain: even before the event has occurred.
The investigators used functional MRI scans with 40 healthy participants who viewed aversive or neutral pictures preceded by predictive warning cues. Previous research reported sex differences in the way in which memory and emotion interact: in women, memory associations were found with a region called the left amygdala. But the association was with the right amygdala in men. This new study refines these findings: they were confined to the ventral amygdala during picture viewing and delayed memory.
Both men and women who had previously been given an indication that gruesome pictures were going to be shown were more likely to remember them.
What this means is that the act of anticipation may play an important role in whether the memory of a tough experience remains fresh and vivid. This makes sense based on our own experiences of events: do you remember the fear associated with a visit to the dentist that built and built before you got there? That anticipation can itself modify the memories of an event.
The findings are published in this week’s issue of the Proceedings of the National Academy of Sciences. They have important implications for the treatment of some psychological conditions such as post-traumatic stress disorder (PTSD) and social anxiety that are often characterized by flashbacks and intrusive memories of upsetting events
We have long known that our memories are not like some video recording forever preserved within our neurons. Some memories are false, many change over time and others lose their emotional charge. It is possible to implant false memories in people, and by re-writing our own life stories we can change the narrative of our lives and how we react to life events.
Samuel Johnson once said that, “The true art of memory is the art of attention.”
I’m quite sure that he is correct, and this research proves it. I’ve always been blessed – or cursed – with a prodigious memory, to the extent of being able to remember the lab values on every patient that I ever saw during my clinical years, and when I was younger being able to read pages of a textbook from memory. I’m quite convinced that my memory is no better than anyone else’s: I’m just a little better at using it.
The trick to using my memory was discovering at an early age that I could remember virtually anything if I really focused my attention on it. So I would focus on the book to the exclusion of everything else for a minute or two. Rest for a minute and then do it again. To this day, that is the best technique that I know for laying down long-term memory. My father also had this faculty, and when I was a youngster he would tell me not to write down things like shopping lists or to construct “To do” lists. He told me that, “if you really have to remember things you will. And if you’re not interested in something you don’t need a “to do” list.”
I only use lists if I have to do something tedious. This is a good test for you. If something that you are doing really engages your attention it is likely one of your core desires, and there is no need to be writing down a list of things to do. If it does not, and you have to write everything down, it’s probably not a core desire. You may still need to write down an action plan, but that’s to get your creative juices flowing, not to stimulate your memory.
I have developed quite a number of techniques for improving memory and concentration. Some are home grown, others modified from methods and techniques that others have taught me. I’ve been collecting and testing them for years. I’m doing a lot of flying this week, so I shall have the time to be put some of them together into a free report. I shall let you know when it’s ready and if you ask, I shall send you a copy.
There is one important reason for writing down thoughts once you have done something, and that is to help them be part of your legacy. That’s a topic to which we are going to return many times in the next few weeks.
“What we anticipate seldom occurs, what we least expected generally happens.”
–Benjamin Disraeli, 1st Earl of Beaconsfield (English Statesman, Novelist and, in 1868 and from 1874-1880, British Prime Minister, 1804-1881)
Re-Writing Our Life Stories and Developing Resilience
“Every man’s story is important, eternal and sacred.”
–Herman Hesse (German-born Swiss Novelist, Poet and, in 1946, Winner of the Nobel Prize for Literature, 1877-1962)
In Healing, Meaning and Purpose, I spend a lot of time discussing the nature of memory – that it does not work like a video recorder, but is a dynamic process – and the value of re-writing your life story. This is a remarkably powerful technique.
What is particularly interesting and useful is to uncover events in our lives that have had two characteristics. First, is that they had a strong subjective impact. And second, that they generated meaning. Breaking up with a partner might generate a lot of emotion and lead you to believe that you are not good in relationships or it could make you think that the other person didn’t appreciate you. Losing a game of football may be painful, but will likely not generate much meaning. Unless your team is on a thirty game losing streak….
A recent study from Quebec published in the Journal of Personality, studied events that we use to define ourselves. Researchers looked at the subjective impact and the meaning-making effect of these self-defining events. This is what they found. When we remember events in our lives that we feel had a major impact on our life story or on our sense of identity, we tend to downplay the negative and emphasize the positive.
When we are asked to think back to those events, we tend to report less sadness and more pride than we actually felt at the time. For positive memories, people reported equally intense positive emotions – for example love – and less negative emotions – such as fear – compared with how they recalled feeling at the time.
What this means is that in the face of change, adversity and opportunity, we are always trying to maintain a positive and coherent sense of self. This is a component of psychological resilience. Someone with clinical depression loses the ability to maintain this positive and coherent sense of self.
This work is also important for people trying to fashion a more positive view of him or herself. While it is usually a good idea to cultivate a positive mental attitude, there are some people for whom such an approach can be disastrous: they are the ones who thrive on negativity. Which one are you?
Simply deciding to change your view of yourself will likely have only a very short-term effect unless you identify and work with cardinal life events. Some forms of psychotherapy revolve around trying to identify the key events that have fashioned our sense of self and that have contributed to our identity. You can begin that process for yourself.
But that is only one part of the equation.
Any long-term change will also involve the attitudes and expectations of other people: none of us lives in a vacuum. I have known countless supremely self-confident musicians, artists and even scientists, whose careers have never got started, because nobody agreed with their evaluation of themselves.
There are a number of ways of presenting yourself in a way that will inspire confidence in other people, and I shall discuss some of those in one of my future programs.
“Every story can be told in different ways.”
–Greek Proverb
Technorati tags: Memory Resilience Story
Hunger and Memory
It’s always a good idea to see how new findings fit in with previous knowledge, and also to see if they make sense. We have previously met the hormone leptin, which is involved in decreasing appetite. Its twin is the hormone ghrelin. Discovered in 1999, ghrelin comes from some of the cells lining the stomach and acts in the hypothalamus to increase appetite. When the stomach is empty it is released into the circulation and travels to the brain where it activates receptors in many different regions. Some research has indicated that one of the reasons why gastric bypass surgery may be effective is because it reduces levels of ghrelin and therefore reduces appetite.
Research published in December 2004 showed that in healthy young men, sleep deprivation caused a decrease in leptin levels and an increase in ghrelin levels, which, as expected, was associated with an increase in hunger and appetite. This is one reason why getting less sleep than you need may cause you to gain weight.
A new study published in the journal Nature Neuroscience, has found an intriguing link between ghrelin and memory. I noticed that the BBC also picked up on this interesting story. Researchers at Yale have discovered that ghrelin acts in an ancient part of the brain known as the hippocampus: so named because it is shaped like a sea-horse. (As an amusing aside, the old German pathologists thought it looked like a silk worm, so that’s what they called it!) The hippocampus has a number of functions, but is most of all essential for learning new material.
The researchers showed that mice who lack the ghrelin gene had 25% fewer synaptic connections between their hippocampal neurons. They then did the next step, and injected normal mice with ghrelin. They promptly increased the number and density of their synaptic connections, which correlated with significant improvements in the animals’ performance on several tests of learning and memory.
So that means that a hormone produced by the stomach can control some brain functions, and this may represent a link between metabolism and the ability to learn. The more that we discover, the more we see the intimate interactions between the brain, intestines and heart.
This link makes good sense: we know that memory can be switched on and off by a range of factors. In order to help us come up with options for handling the environment and for remembering things to avoid, memory is often switched on at times of stress. Hunger is a form of stress, and it makes good biological sense that we might be more alert and better able to remember and to recall information when hungry. It stands to reason that this has enormous survival advantage. If our early ancestors had not had this hunger/memory link, they might well have died out in the competition for food.
This gives some credence to the old advice that it is best not to try to study or to take an exam on a full stomach. Just have enough food to make sure that you have ample fuel, and that you are not distracted by hunger pains.
Technorati tags: hunger, memory, stress, study habits
