John M. Talmadge, M.D.

A Blog Covering Many Topics

New Brain Discovery? Lymph!

Although we don't know for certain that new treatments are just over the horizon, here's some potentially exciting news. Scientists at the University of Virginia have discovered previously unknown lymphatic vessels in the outer layers of the brain. These vessels appeared to link the brain and spinal cord with the rest of the body’s immune system. This study used mice and human samples, vessel structure was investigated in the mice, and the observations followed up in the human samples. This was an animal study using mice to investigate the structure and function of lymphatic vessels in the brain. In fact, this story has been circulating for awhile, but recently it's been highlighted in several stories. The good news is that this may mean that the original studies are standing up to scrutiny by other scientists.

The discovery may require a reassessment of our assumptions about lymph drainage in the brain and its role in diseases involving brain inflammation or degeneration, such as Alzheimer’s disease and multiple sclerosis. The study was published in the peer-reviewed scientific journal Nature.

When I was in medical school, we were taught that the central nervous system (brain and spinal cord) did not have a typical lymphatic drainage system. Lymph is the immune fluid that circulates through the body, containing white blood cells to fight infection and destroy abnormal cells. This study aimed to look at the circulation of lymph in the mouse brain, but mice and humans do not have identical biology, so the findings may not be directly applicable. 

The study involved complex laboratory techniques, using a fluorescent antibody to assess the alignment of cells within the brain, examination for markers associated with a lymphatic drainage system and looking at the functional capacity of identified vessels to carry lymphatic fluid to and from the brain. 
Human samples taken from the brain at autopsy were used to investigate any structures found in mice.

The scientists found that the outer protective layers of the mouse brain showed cells that were clearly lined up, which suggested that these were vessels with a unique function. These cells showed the characteristic features of functional lymphatic vessels. These vessels appeared able to carry both fluid and immune cells from the fluid surrounding the brain and spinal cord (the cerebrospinal fluid), and were connected to the lymph nodes in the neck. The location of these vessels may have been the reason they have not been discovered before, thereby causing the belief that there is no lymphatic drainage system in the brain.

This may mean current thinking about how the brain works needs to be reassessed. The researchers go on to say it could be the malfunction of these vessels that could be the cause of a variety of brain disorders, such as multiple sclerosis and Alzheimer’s disease.

Summary: This mouse study has examined the circulation of lymph in the brain. It discovered previously unknown lymphatic vessels in the outer layers of the mouse brain. If accurate, the findings may call for a review of how the immune system in the brain functions, and shed new light on its role in brain diseases involving brain inflammation or degeneration. Though animal research can give a good insight into biological and disease processes, and how they may work in humans, the processes in humans and mice are not identical. Further studies are needed to confirm these findings and to assess whether this knowledge is transferable to humans. As such, it is too early to say whether the findings could one day have any implications for the treatment of degenerative brain conditions such as multiple sclerosis or Alzheimer’s.  

The original article in Nature can be found here.

Child Development and Brain Health

In teaching medical students about psychiatry, I say that there are two key factors that influence how an individual fares in life. One factor is biological vulnerability, and the other factor is developmental opportunity. A person may be born with a genetically influenced condition like dyslexia, or a genetic vulnerability to addiction (alcoholism, for example, tends to run in families). Someone with biological vulnerability may, however, do quite well if life is filled with developmental opportunity. A person who grows up in a stable family, who attends good schools, and who gets a good job has a life rich in developmental opportunities that may ultimately enable them to overcome the biological vulnerability.

Someone with dyslexia may attend schools that recognize the deficit and help the child learn to read well; or they may have the help of a skilled educational psychologist who can work the magic and overcome the learning differences. On the other hand, someone who grows up in less fortunate circumstances, like living in poverty or suffering a broken home, may do very well if they are biologically resilient and strong. Problems arise, however, when some suffers biological vulnerability as well as a life short on developmental opportunity. When we see the chronically mentally ill, we often see the overlap of these two conditions.

New research suggests that family income, and to a lesser degree parental education, are associated with brain structure differences in children and young adults. Focusing on brain regions critical for language, memory, and executive function in participants aged three to 20 years, scientists found that small differences in income were associated with relatively large differences in brain surface area in young people from the lowest-income families. This effect was smaller in higher-income families. Higher income was also associated with better performance in tests of cognitive ability. Increased levels of parental education were also related to increased brain surface area, although this effect was smaller when compared to the influence of income.

Although these study results do not suggest that low-income children have poor cognitive function, they indicate that interventions to reduce family poverty may help reduce socioeconomic disparities in child development and achievement.  The full text of the findings can be found here.

Traumatic Brain Injury: Progress

A new study reveals that individuals with traumatic brain injury (TBI) have significantly more difficulty with gist reasoning than traditional cognitive tests. Using a unique cognitive assessment developed by researchers at the Center for BrainHealth at The University of Texas at Dallas, findings published Friday in the Journal of Clinical and Experimental Neuropsychology indicate that an individual's ability to "get the gist or extract the essence of a message" after a TBI more strongly predicts his or her ability to effectively hold a job or maintain a household than previously revealed by traditional cognitive tests alone. The study also further validates the Center for BrainHealth's gist reasoning assessment as an informative tool capable of estimating a broad range of daily life skills.
"Gist reasoning characterizes a meaningful, complex cognitive capacity. Assessing how well one understands and expresses big ideas from information they are exposed, commonly known as an ability to "get the gist", is window into real life functionality. I do not know of any other paper and pencil test that can tell us both," explained Asha Vas, Ph.D., research scientist at the Center for BrainHealth and lead study author. "Although performance on traditional cognitive tests is informative, widely-used measures do not paint the full picture. Adults with TBI often fare average or above on these structured measures. All too often, adults with brain injury have been told that they ought to be fine; in reality, they are not doing and thinking like they used to prior to the injury and struggle managing everyday life responsibilities years after the injury. Gist reasoning could be a sensitive tool to connect some of those dots as to why they are having trouble with real-life functionality despite falling into the range of "normal" on other cognitive tests." For more details and the longer article, click here.

Aging Brain? Not So Bad...

From Harvard Health Publications at Harvard Medical School comes some exciting news about the aging brain.

At middle age, the brain begins to draw on more of its capacity for improved judgment and decision making.
If you forget a name or two, take longer to finish the crossword, or find it hard to manage two tasks at once, you’re not on the road to dementia.
What you’re experiencing is your brain changing the way it works as you get older. And in many ways it’s actually working better. Studies have shown that older people have better judgment, are better at making rational decisions, and are better able to screen out negativity than their juniors are.
Although it may take you a little longer to get to the solution, you’re probably better at inductive and spatial reasoning at middle age than you were in your youth.

The brain changes as we get older, and in some ways it works better as we get older.

How is it possible for older people to function better even as their brains slow? “The brain begins to compensate by using more of itself,” explains Dr. Bruce Yankner, professor of genetics and co-director of the Paul F. Glenn Laboratories for the Biological Mechanisms of Aging at Harvard Medical School. He notes that MRIs taken of a teenager working through a problem show a lot of activity on one side of the prefrontal cortex, the region we use for conscious reasoning. In middle age, the other side of the brain begins to pitch in a little. In seniors, both sides of the brain share the task equally. The cooperative effort has a payoff. “Several studies suggest that seniors who can activate both sides of the brain actually do better on tasks, while those who can’t do worse,” Dr. Yankner says.

If you’ve found that it’s a little harder to carry on a conversation while searching your bag for your keys, MRI studies offer some clues. They show that in younger people, the area of the brain used to do a task goes dark immediately once the task is completed, while in older people it takes longer to shut down. As a result, it’s harder for the older brain to take on several tasks, because not only do you need to use more of the brain for any single task, but the brain also has a harder time letting go of a task. So even after you fish out your keys, you may have trouble getting back into the conversation.
What about the moments when you find yourself driving down the street without any recollection of having passed the last few blocks? Or the times you’ve locked the car door with your keys in the ignition? On those occasions your brain may have slipped into the default mode, which controls processes like remembering and daydreaming that are not required for a directed task. Imaging studies show that interconnected regions of the brain dubbed the “default network” grow more active with age, indicating that as we age we spend more time daydreaming.


At The Center for BrainHealth, as at Harvard, we are discovering that the more mature brain actually has advantages over its younger counterpart. These findings came as a surprise to many people, who were accustomed to seeing “senior moments”—groping for the right word or taking longer to articulate your thoughts—as a sign that the brain was on the skids. Yet even in professions where youth is valued, testing has shown that maturity has advantages.

For example, in a study of air-traffic controllers and airline pilots, those between ages 50 and 69 took longer than those under 50 to master new equipment, but once they had, they made fewer mistakes using it. (Keep this in mind when you’re trying to conquer a new computer program or adapt to a new car!) The mastery that comes with maturity is due to changes in your glands as well as your brain. Declining levels of testosterone—even in women—result in better impulse control. The end of the hormonal roller coaster of menopause may also contribute to emotional stability. After midlife, people are less likely to have emotional issues like mood swings and neuroses that interfere with cognitive function.

Most importantly, the wealth of knowledge from decades of learning and life experience enables you to better assess new situations. At midlife, most people are more adept at making financial decisions and getting to the heart of issues than they were when they were younger.

In most people, these abilities improve with age:

Inductive reasoning. Older people are less likely to rush to judgment and more likely to reach the right conclusion based on the information. This is an enormous help in everyday problem solving, from planning the most efficient way to do your errands to managing your staff at work.

Verbal abilities. In middle age, you continue to expand your vocabulary and hone your ability to express yourself.

Spatial reasoning. Remember those quizzes that require you to identify an object that has been turned around? You are likely to score better on them in your 50s and 60s than you did in your teens. And you may be better at some aspects of driving, too, because you are better able to assess the distance between your car and other objects on the road.

Basic math. You may be better at splitting the check and figuring the tip when you’re lunching with friends, simply because you’ve been doing it for so many years.

Accentuating the positive. The amygdala, the area of the brain that consolidates emotion and memory, is less responsive to negatively charged situations in older people than in younger ones, which may explain why studies have shown that people over 60 tend to brood less.

Attaining contentment. Years ago, researchers were surprised to find that people seem to be more satisfied with their lives as they age, despite the losses that accumulate with passing years. This is probably because they tend to minimize the negative, accept their limitations and use their experience to compensate for them, and set reasonable goals for the future. Dr. Yankner notes that this trait may be innate, because it is prevalent even in the United States and other Western nations, which tend to value youth over age.

Being Mindful: Getting Started

Meditation is not as difficult as most people think. Here are some tips from

Find a good spot in your home or apartment, ideally where there isn’t too much clutter and you can find some quiet. Leave the lights on or sit in natural light. You can even sit outside if you like, but choose a place with little distraction.

At the outset, it helps to set an amount of time you’re going to “practice” for. Otherwise, you may obsess about deciding when to stop. If you’re just beginning, it can help to choose a short time, such as five or ten minutes. Eventually you can build up to twice as long, then maybe up to 45 minutes or an hour. Use a kitchen timer or the timer on your phone. Many people do a session in the morning and in the evening, or one or the other. If you feel your life is busy and you have little time, doing some is better than doing none. When you get a little space and time, you can do a bit more.

Take good posture (see instructions above with actor Sandra Oh above) in a chair or on some kind of cushion on the floor. It could be a blanket and a pillow, although there are many good cushions available that will last you a lifetime of practice. You may sit in a chair with your feet on the floor, loosely cross-legged, in lotus posture, kneeling—all are fine. Just make sure you are stable and erect. If the constraints of your body prevent you from sitting erect, find a position you can stay in for a while.

When your posture is established, feel your breath—or some say “follow” it—as it goes out and as it goes in. (Some versions of the practice put more emphasis on the outbreath, and for the inbreath you simply leave a spacious pause.) Inevitably, your attention will leave the breath and wander to other places. When you get around to noticing this—in a few seconds, a minute, five minutes—return your attention to the breath. Don’t bother judging yourself or obsessing over the content of the thoughts. Come back. You go away, you come back. That’s the practice. It’s often been said that it’s very simple, but it’s not necessarily easy. The work is to just keep doing it. Results will accrue.

The Brain: A Good Introduction

One of my favorite journals, New Scientist, has an excellent introduction to the brain and how it works.

The brain is the most complex organ in the human body. It produces our every thought, action, memory, feeling and experience of the world. This jelly-like mass of tissue, weighing in at around 1.4 kilograms, contains a staggering one hundred billion nerve cells, or neurons.

The complexity of the connectivity between these cells is mind-boggling. Each neuron can make contact with thousands or even tens of thousands of others, via tiny structures called synapses. Our brains form a million new connections for every second of our lives. The pattern and strength of the connections is constantly changing and no two brains are alike.

It is in these changing connections that memories are stored, habits learned and personalities shaped, by reinforcing certain patterns of brain activity, and losing others. To read the article, click here.

SMART Training for Teens

The Center for BrainHealth has created an exciting opportunity for Teens this summer – Teen SMART Camp!
Teen SMART Camp is a great chance for your children or grandchildren to boost their frontal lobe functioning and gain important strategies for learning.
For questions and registration, please contact Lindsay Gehan at or 972.883.3310

Over the last six years, BrainHealth researchers have trained more than 27,000 students in SMART through research grants. Results have shown significant changes in frontal lobe regions responsible for higher order thinking and problem solving after only 10 hours of training. SMART has shown substantial improvements in academic performance in those who have participated to date.
SMART is a series of seven cognitive strategies that can be applied to any learning context. As students’ progress through these steps, they learn to discard unsuccessful and superficial learning styles and to adopt a more robust, focused, and deeper-level strategic learning approach. Upon completion of the SMART training, students can apply the methodology to any subject and have been shown scientifically to do so over an extended period of time with success.
This summer’s teens will begin SMART Camp by receiving comprehensive strategy instruction, teaching them to use their brains more efficiently to improve learning. SMART campers employ their new strategies in a variety of fun learning activities involving academic content as well as personally-relevant materials such as their favorite song lyrics, television shows, magazine articles, or movies, emphasizing organizational and motivational skills. The training is designed to help the teens apply their newly learned strategies to everyday situations. Each camper works on an individual and a group project over the course of the camp to practice planning, goal setting and time management.
The brain is primed for higher order reasoning beginning in adolescence. As a result, this SMART program is offered for students who will enter the 7th through 12th grade in Fall 2015.
SMART Camp has a maximum enrollment of 20 students and are filled on a first-come, first serve basis. The full payment amount is due before the camp begins.
June 22-26th 2015 – The day will start promptly at 9:00 am and conclude at 3:00 pm.
SMART Camp takes place over one week at the Center for BrainHealth.
Please contact Lindsay Gehan at or 972-883-3310 for more information

Change Your Brain

And now…a word or two about good science and having a healthy brain. We offer a range of programs at the Brain Performance Institute to help people of all ages and conditions improve and extend peak brain performance throughout their lives. By evaluating brain fitness and applying proven brain-training methods, the Brain Performance Institute will train individuals to think smarter and exploit their greatest natural resources — their brains.

A unique cognitive assessment that measures cognitive reserve in pivotal areas of higher-order mental functioning, all of which rely on robust frontal lobe function. It is just as essential to measure and monitor brain fitness as it is to measure and monitor physical fitness. Get a benchmark of your brain’s health.

The high performance brain training program, Strategic Memory Advanced Reasoning Training (SMART®Winking, was developed by Center for BrainHealth cognitive neuroscientists and is based on more than 25 years of scientific study. The training program targets improvement in the frontal lobe of the brain and is based on cognitive neuroscience principles of how to build strategic thinking, advanced reasoning and innovative problem-solving skills. SMART sessions include personalized training materials and integrated practice sessions.

I joined the staff at The Center for BrainHealth and BPI after extensive contact with the scientists and clinicians there. Over a period of months I found myself returning at least once or twice weekly to attend a lecture, to discuss research, or to interact with my friends on The Warrior Team, a powerful resource for veterans. I remember the day in November 2014 when I spoke with Dr. Sandra Chapman, the CEO, and she asked me whether I was enjoying my visits. "Are you kidding me?" I said, "I want to be more than a visitor—I want to work here!" Needless to say, I was both honored and extremely delighted when, early in 2015, I got the call and the invitation to be Senior Medical Advisor for CBH and BPI.

Neuroscience of Belief

In the current issue of New Scientist I came across a good article on the neuroscience of belief. Graham Lawton writes, in part: Beliefs define how we see the world and act within it; without them, there would be no plots to behead soldiers, no war, no economic crises and no racism. There would also be no cathedrals, no nature reserves, no science and no art. Whatever beliefs you hold, it's hard to imagine life without them. Beliefs, more than anything else, are what make us human. They also come so naturally that we rarely stop to think how bizarre belief is.
In 1921, philosopher Bertrand Russell put it succinctly when he described belief as "the central problem in the analysis of mind". Believing, he said, is "the most 'mental' thing we do" – by which he meant the most removed from the "mere matter" that our brains are made of. How can a physical object like a human brain believe things? Philosophy has made little progress on Russell's central problem. But increasingly, scientists are stepping in.
The neuroscientific investigation of belief began in 2008, when Sam Harris (Harris, S., Sheth, S. A. and Cohen, M. S. (2008), Functional neuroimaging of belief, disbelief, and uncertainty. Ann Neurol., 63: 141–147) at the University of California, Los Angeles, put people into a brain scanner and asked them whether they believed in various written statements. Some were simple factual propositions, such as "California is larger than Rhode Island"; others were matters of personal belief, such as "There is probably no God". Harris found that statements people believed to be true produced little characteristic brain activity – just a few brief flickers in regions associated with reasoning and emotional reward. In contrast, disbelief produced longer and stronger activation in regions associated with deliberation and decision-making, as if the brain had to work harder to reach a state of disbelief. Statements the volunteers did not believe also activated regions associated with emotion, but in this case pain and disgust.

To read the full article, click here.