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Thursday, July 13, 2017

A Possible Remedy for Depression

In the United States, some 5-7% of the population is clinically depressed in any given year. Over a lifetime, there are high odds that each of us has been depressed at some point. Sadly for seniors, the likelihood can increase with age.
A new treatment approach that combines mindfulness meditation and aerobic exercise seems promising. In a recent study, 22 clinically diagnosed patients with major depressive disorder were put on a treatment regimen that begins with 30 minutes of mindfulness meditation and is followed by 30 minutes of aerobic exercise. Thirty people without depression symptoms served as a comparison group. In the meditation session, patients were told to focus on the present moment and their slow, deep breathing and excluding all mind-wandering and intrusive thoughts. Exercise was on a treadmill or stationary bicycle.
At the end of eight weeks, patients were assessed again for depression symptoms, and symptoms decreased on average by 40%. An electrically evoked brain-wave response characteristic of executive control function was notably increased in the clinically depressed group.
Like any illness, an ounce of prevention is worth a pound of cure. In the case of depression, two approaches can help. The first and foremost is to live a life of worthy purpose that gives life meaning and genuine pleasure. It is hard to be depressed when you believe that you make a positive difference in the lives of others. Of course, your efforts will fail from time to time, and people will not always value your efforts on their behalf. But you can take comfort in knowing that you mean well and are on the right track.
The second approach is to avoid the cues that remind you of negative. I have written several related posts at this archived site ( "depression" in the search field at upper right). I have argued that continual rehearsal of negative emotions, which can be done explicitly or implicitly, is the driver of clinical depression. As a neuroscientist, I know that rehearsal of thoughts and feelings strengthens the mediating synapses and circuits. Consciously rehearsing bad events and our depressive response cements depression in neural circuitry.
So, it would seem important to focus on ways to block the retrieval cues. One solution that sometimes works is to change environments. Even if you don’t know what the depression cues are, you know they can somehow be embedded in the current environment and lifestyle. Maybe the problem is with some of the people you run around with. People who drag you down are not all that hard to spot. Avoid them. Maybe the problem is with your career or work environment, which has saddled you with too many depressing experiences. Staying in that environment assures that depression triggering cues will be encountered again.
It is not always feasible to change dealings with certain people, or the environment or lifestyle. You may not be able to change jobs or careers for economic or other practical reasons. In those cases, it helps to promote recall of happy experiences as a substitute.
Common experience and a great deal of formal research have shown the usefulness of “happy thoughts” as a way to boost positive mood. Here, the trick is to enhance recall of the buried memories of happy experiences. The same neural mechanisms involved in rehearsal and recall of depressing experiences are involved. Triggers that recall happy experiences do so at the expense of triggers that would trigger depressive feelings.
Recent research emphasizes the importance of memory as therapy for depression. Depressed patients were trained to use one or the other of two memory techniques for strengthening the memory of happy events in their lives. Both memorization methods were equally effective when recall was tested right after the training. But a week later, experimenters made a surprise phone call to each patient and asked them to recall the happy thoughts again. This time, clearly better recall occurred in the patients who had used the method-of-loci method. If we can generalize these results, it means that patients can alleviate their depression if they train their brains to be more effective at remembering positive events. Your life should be more satisfying and less depressing when you consciously train your brain to remember the good times.


Alderman, B. L. et al. (2016). MAP training: combining meditation and aerobic exercise reduces depession and rumination while enhancing synchronized brain activity. Transl. Psychiatry. 6(e276). doi: 10.1038/tp.2015.225

Dalgleish, T. et al. (2013). Method-of_Loci as a mnemonic device to facilitate access to self-affirming personal memories for individuals with depression. Clinical Psychological Science. Feb. 12, DOI: 10.1177/21677026112468111.

"Memory Medic" has four books on improving learning and memory:

For parents and teachers: The Learning Skills Cycle.
For students: Better Grades, Less Effort
For everyone's routine living: Memory Power 101
For seniors: Improve Your Memory for a Healthy Brain. Memory Is the Canary in Your Brain's Coal Mine

For details and reviews, see Memory Medic's web site:

Monday, July 03, 2017

Memory Training Produces Lasting Effects

I first got interested in memory training at age 15 when my dad was a salesman for the Dale Carnegie leadership course, which included a section on memory training. My dad taught me some tricks that enabled me to memorize the gist of what was on every page of a magazine, by page number, in 30 minutes. I used to put on demonstrations for prospective enrollees. Before the recruitment meeting started, the leader would tell the audience, "Everybody see Billy here. Stand up Billy. I am going to give him this latest magazine issue, which he has never seen, and let him study it for 30 minutes. Then we will interrupt the meeting and you can ask him what is on any given page. Or you can tell him what is on a page, and he can tell you the page number." To my own astonishment, I could do it and it was not that hard. The basic gimmick was first to memorize a number code that converted page numbers into a visual image. For example, the code for 20 was "noose," as in a hangman's noose. Then I would convert the content on page 20 to an image or image series that captured the gist of the content. Then I would link the page-code image and the content image. For example, if the content on page 20 was about Elvis joining the army and his boot camp experiences, I would picture Elvis, guitar and costume, being trucked off in a military truck to a boot camp, where they put him through gymnastic exercises, marching, and simulated combat, and then they hung him. This idea and many other mnemonic devices are explained more fully in my book, Memory Power 101.
At the time, I wondered if this kind of mental exercise would have some sort of spill-over, lasting effect. Hopefully, it would help me in school. I think it did (I never made less than an A), but I never had an objective way to verify that.
Most readers have probably heard about "memory athletes," people who use mental imaging mnemonic devices to accomplish astonishing feats of memory. Such athletes can, for example, memorize in five minutes 550 words or the sequence of four shuffled decks of cards.
Until now, there were few studies of whether the brains of such athletes are changed in any lasting way by the memory training.
One indication of lasting change had been reported in London taxi drivers who were revealed by brain scans to have an enlarged hippocampus, a large paired structure in the brain that forms memories and also maps spatial locations (London streets are convoluted in their layout and notoriously difficult to learn).
A more direct test of brain change has been recently reported. In the first experiment, 23 of the top 50 world-ranked memory athletes were compared with control normals of similar age, gender and IQ.  Brains were scanned in all subjects under two conditions: first, while they were relaxed and letting their minds wander, and second, while they were trying to memorize a list of 72 words.
Not surprisingly, the memory champions missed only two words on average when recalling the list 20 minutes later, whereas their controls missed nearly half. The brain scans revealed patterns of connectivity among various brain regions in the memory champions.
Investigators then wanted to know if memory training of the controls would produce lasting changes in them. Thus, the controls were separated into three groups: one was asked to practice the Method of Loci memory technique for half an hour every day for a total of six weeks. A second group practiced a very challenging working-memory task, the dual N-back, in which they had to memorize a sequence of spoken words while paying attention to the locations of a moving square on the computer screen, and identify when a letter or position matches one that appeared earlier. The last group just lived their normal life without memory training for the test period of six weeks.
When tested right after training on memorizing a random list of words, only the Method of Loci group showed improved memory. Comparison of brain scans before and after the six weeks revealed connectivity changes, much like those of memory champions. Also, the change in connectivity was a reliable predictor how well they performed in the memory test. Moreover, the connectivity changes and improved memory ability persisted for at least four months afterwards.
The authors of the study report could not explain why dual N-back training had no lasting effect (other than getting better at N-back tests), as might be expected because it is a very demanding task. But I think the reason is that N-back training involves a different aspect of memory that does not generalize to memorizing word lists.
Anyway, I feel better now that my memory experiences at 16 have served me well in the succeeding years. This is consistent with what I had learned about neuroplasticity as an adult neuroscientist: the brain has to change to store what you learn in memory. How that happens is explained in another book of mine, Mental Biology.


Dresler, M., et al (2017). Mnemonic training reshapes brain networks to support superior memory. Neuron, 93: 1-9.

Klemm, W. R. (2012) Memory Power 101. New York: Skyhorse.

Klemm, W. R. (2014). Mental Biology: The New Science of How the Brain and Mind Relate. New York: Prometheus.

See rave reviews of "Memory Medic's" books at
Available at Amazon, Barnes and Noble, and the publisher web sites.

Tuesday, June 20, 2017

Learning Stuff While Missing the Point

As a college professor for many decades, I am always amazed at how so many students pass exams while having so little understanding. If I taught math, it would probably be different, because the task in math is to solve problems, which you can't do if you don't understand how to construct and solve appropriate equations. But for most other subjects, it is amazing how much students can learn with so little understanding.
This problem also exists in the real world outside of academia. I have recently become engaged as a volunteer tutor in our community's citizenship preparation class for immigrants. This past week the topic was George Washington, and the two instructors spent a lot of time teaching trivial things, such as when he was born, where he was born, what he was (general, president), the name of his home. Nothing was presented about his philosophy about freedom and government. I had to remind the teachers and the class that after he had done such a good job in his two terms as President, many citizens pressed him to become king. He, of course, refused. I don't know what he said to the petitioners, but I can guess he thought to himself, "We just spent years fighting where many of our fellows died to create a new country based on freedom. You turkeys missed the whole point. You didn't learn a damn thing."
During that same class period, the instructors taught about our holidays, that is, what and when they were, but not why they were. For example, we talked about the President's day holiday. During the tutoring session, I asked the immigrants at my table why we celebrate all the Presidents, even though most of them had conspicuous human weaknesses, and many of whom had views and policies that the immigrants would not have supported or voted for. Blank stares encircled our table. I had to remind everybody that we honor Presidents we don't like because more than half the country did like them. If you understand anything about freedom, you have to respect every President, because otherwise you disrespect over half the country and worse yet, the principle of democratic government. Otherwise, you are leading the country down the jungle path of becoming a banana republic (which of course is what these Hispanic immigrants are used to).
There are real-world lessons today in the world of Trump. When you popularize the idea of his assassination and shout in rage "He is not my President," you are shouting at your fellow citizens who insist that he is their President and should be yours too. Dishonoring the man dishonors the office and the fundamental philosophy of our governing principles. This is vastly more important than knowing what was being taught about the holiday.
The right lessons about our government are apparently not being taught to citizens in our k-12 schools. Numerous polls uniformly have revealed that the typical high school graduate knows very little about U.S. history. School history textbooks are roundly criticized for inaccuracy, bias, and omissions. What little is learned is about the flaws in our past, such as treatment of Indians, slavery, and the Vietnam War. I have verified this in conversations with my grandchildren. The young people I talk to know nothing about the Federalist Papers. They have little appreciation for how creative the ideas in the Constitution were at the time and how they have had at least some impact everywhere in the world. They know very little about what our "greatest generation" did in World War II to save the world from despotism.
The larger point, of the need to understand the factoids you are learning, applies in all aspects in life: school, workplace training, and relationships with people of different backgrounds. In everything we learn we should get in the habit of asking ourselves certain questions:
·         Do I understand what this means?
·         How much can I learn from it, not just of it?
·         What are the limitations of this information? Where is it wrong or incomplete?
·         What are the implications of this information?
·         To what good purpose can I put this information?
Understanding is much more demanding and valuable than just knowing. I might add as the "Memory Medic" that this perspective on learning makes it easier to remember what you learn. The best way to remember factoids is the thinking required to understand them.

"Memory Medic" has four books 

on improving learning and memory:

For parents and teachers: The Learning Skills Cycle.
For students: Better Grades, Less Effort
For everyone's routine living: Memory Power 101
For seniors: Improve Your Memory for a Healthy Brain. Memory Is the Canary in Your Brain's Coal Mine

For details and reviews, see Memory Medic's web site:

Tuesday, June 13, 2017

Background Noise While Studying

Most people have trouble focusing when there are distractions, and that will surely impair learning. Learning can be impaired by distracting background sounds. That is why teachers generally encourage students to study in quiet environments. Children, however, like extra stimulation when studying, perhaps because they view study as boring. So, a common practice is to play music or even have the radio or TV on. I have written about music effects on learning before (, but now there is other information I would like to share.

Personality of the learner may be an important variable. Adrian Furnham and Lisa Strbac of University College, London, found that both background music or office noises impaired performance of introverts in tasks involving reading comprehension, mental arithmetic, and prose recall. Performance in silence was the same for both personality types, suggesting that introverts have a special need for silence in their study environments.

The notion has surfaced that it might be beneficial to mask distracting sounds by playing white noise while studying. White noise is a random mixture of sound frequencies that when heard in low volume can improve detection of a simultaneous isolated signal with equal power of any frequency. Perhaps this is because the presence of a homogenous signal (white noise) improves the contrast with a novel superimposed signal. A contributing factor might be the brain’s usual response of habituating to a constant stimulus, effectively creating an empty-stimulus state in which other stimuli would be augmented. A couple of years ago a study was reported indicating that a white-noise background can improve memory in youngsters with Attention Deficit Disorder.

What happens in a brain exposed to white noise has been revealed in fMRI brain-scan studies of young adults. The study’s behavioral test indicated slightly improved recognition memory of scene images and scans. An associated increased activity occurred in brain positive reinforcement pathways and in auditory cortex.

However, some caution is needed in interpreting these results. One caveat is that the study of adults used recognition memory (as in “Do you remember seeing this scene?”), which is much less robust than being able to generate a recall without cuing. Another caveat is the lack of systematic evaluation of the decibel level of white noise. At some point, the sound is certain to be distracting or even irritating. In fact, people on average report that such noise is slightly aversive and strongly aversive by some subjects. The adult study used a white noise of 20-5000 Hz at 70 dB via headphones. If one does not deliver white noise via headphones, other sounds in the room could negate whatever beneficial effect white noise might have.

Steven Smith at my university found that recall of memorized words was better 48 hours after learning if the sounds used during word presentation, either music or white noise, were repeated during the recall session. This reflects a common observation that recall is enhanced if you are tested in the same environment as when you learned the test material. Using sound in this way is not practical in school situations, but it could improve the efficacy of self-testing in one's home environment.

We should not accept uncritically the studies that advocate using white noise during study. One study revealed that exposure to background noise improved performance for inattentive children but worsened performance for attentive children. Thus, white noise may be a distraction for attentive children and only helps with inattentive children because their innate distractibility is activated less when the noise background is monotonous and uninteresting.

In the most recent study of this issue, white-noise (20-20,000 Hz, 70 dB, via headphones) during initial learning impaired recall. The authors concluded that white noise has no general beneficial effect on thinking and memory.

What this tells me is that white noise might have some value if there is general room noise that needs to be masked. This might be especially true for people with attention deficits who are especially distracted by noise. Another possibility, which as far as I know has not been tested, is to have a soft background noise of rain in a tropical rain forest or waves lapping on the beach. Those sounds would surely be relaxing and provide a uniform sound background.

But why have any sound at all? What is wrong with utter silence when you are trying to concentrate? When it comes to learning, it is hard to beat the silence of the library.


Furnham, Adran, and Strbac, Lisa. (2010). Music is as distracting as noise: the differential distraction of background music and noise on the cognitive test performance of introverts and extraverts. Ergonomics, 45(3).

Herweg, N. A., and Bunzeck, N. (2015). Differential effects of white noise in cognitive and perceptual tasks. Frontiers in Psychol. (3 Nov.).

Rausch, V. H., Bauch, E. M., and Bunzek, N. (2013). White noise improves learning by modulating activity in dopaminergic midbrain regions and right superior temporal sulcus, J. Cognitive Neuroscience, (Dec. 17) 26(7), doi: 10.1162/jocn_a_00537.

Söderlund, Göran BW  et al. (2010). The effects of background white noise on memory performance in inattentive school children. Behavioral and Brain Functions20106:55
DOI: 10.1186/1744-9081-6-55

Smith, Steven M. (1985). Background music and context-dependent memory. Amer. J. Psychol. 98(4), 591-603.

"Memory Medic" has four books on improving learning and memory:

For parents and teachers: The Learning Skills Cycle.
For students: Better Grades, Less Effort
For everyone's routine living: Memory Power 101
For seniors: Improve Your Memory for a Healthy Brain. Memory Is the Canary in Your Brain's Coal Mine

For details and reviews, see Memory Medic's web site:

Monday, June 05, 2017

Learning to Be Hostile

In U.S. culture, hostility seems to be growing to epidemic proportions. We are teaching each other that hostility is acceptable and even necessary. Recently in my local newspaper, a letter to the editor by  Sana Rahman lamented that “people do not seem to have the same regard and respect for others that we used to have.” I have lived long enough to know she is right.

Taking advantage of others is rampant. Everybody from corporations to individual free loaders want to feed at the federal trough. We legitimize free and undeserved stuff from government as entitlement.  Ripping off taxpayers occurs at all levels, especially in health care programs, government contracts, tax returns, and in all manner of subsidies.

Violence is all around us in video games and movies and in murders in cities like Chicago and New Orleans. We read of horror stories where onlookers of rapes and beatings regard it as entertainment, refusing to intervene or call the police. In some cities, police are targeted for abuse and even killing.

We feel little obligation for thoughtful consideration of the beliefs and views of others. On college campuses, students and professors riot to block free speech of speakers who have different views. The mayor of Berkeley, California is quoted in the June 12 Time article on the university riots was quoted as saying "This level of political violence is something we have not seen before." Fascist intimidation of unwanted speech is being conducted by groups that strangely call themselves antifascist (and these are our best and brightest?).

The hatred of President Trump has reached sociopathic levels. Comedians who used to think their job was to be funny now think their job is to demean conservatives.  Movie stars seem to have similar objectives. To be elected, politicians increasingly rely on character assassination of opponents. Republican and Democrat legislators regard each other as enemies and even enemies of the country. Citizens are politically polarized in socially destructive ways.

Hatred is becoming epidemic, and the spread is promoted by the teaching that the ends justify the means. Hatred is okay when it is directed at people we carelessly define as evil. We teach each other to be desensitized to violence. Like a response to virulent virus, our immune response to violence has become exhausted.

Religious institutions that remind us of our obligation to love our neighbors and even our enemies are losing massive numbers of members. Sana Rahman asked us to pray for a return of the regard and respect for others that we used to have. We must help answer those prayers by a change in our own hearts.

Dr. Klemm's latest book, for parents and teachers, is "The Learning Skills Cycle. A Way to Re-think Education Reform." It is available from most all book vendors.

Monday, May 29, 2017

Video Game Addiction

If you don't think kids get hooked on video games, think again. If you Google "video game addiction," you will find more than a dozen pages of Web sites dealing with this issue. There are also many pages of formal research papers found via search on Google Scholar.

The point at which gaming becomes an actual addiction is hard to define, but some 7-21 criteria can measure the addiction. These criteria include modification of mood, conflict, behavioral problems, and, more tellingly, the same phenomena seen in drug addiction (tolerance and withdrawal symptoms).

So many kids spend nearly every possible moment glued to a game screen that an addiction recovery program known as ReSTART was developed eight years ago in which addicts receive individual and group therapy in a resident campus. The ReSTART therapy program requires patients to take a 45-90 abstention from computer screens. Part of the reason that addiction develops in the first place is the strong positive reinforcement provided by developing game prowess. The young person's self-esteem becomes entangled with gaming.  The therapy program aims at finding other substitute reinforcers for self-identity and self-esteem. Training is provided in the basic life skills that have been neglected from the years of immersion in gaming.

The organization's guiding principle is "Connect with life, not your device." Children who become addicted to video games withdraw from daily living. They are most likely to be male, poorly developed physically, and socially awkward. They often suffer from ill-defined anxiety.

Just how widespread is video game use? Apparently 155 million Americans play video games at least three times a week. Particular concern is the violent nature of many video games, and it is clear that playing such games stimulates the players to be more aggressive.

The Dana Foundation and the American Association for the Advancement of Science recently sponsored a conference on internet gaming. The speaker from ReSTART, co-founder Hilarie Cash, predicted that internet gaming is so addictive that it will probably become listed in newer editions of the Diagnostic and Statistical Manual of mental Disorders.

Another speaker, psychology professor Craig Anderson, summarized the evidence that violent video games promote aggressive behavior in the player. Increases occur in hitting, kicking, punching, biting, fights at school, and juvenile delinquency. Anderson points out that longitudinal studies rule out the possibility that children who are already violent are the ones who become addicted to violent video games. Playing violent games actually makes children more violent.

Video games that are not violent may help develop mental quickness and other cognitive skills. But like much in life, too much of a good thing is a bad thing.


Lemmens, Jeroen S. et al. (2009). Development and validation of a game addiction scale for adolescents. Media Psychology. 12(1), 77-95.

Jarvis, Michaela. 2014. Video games: the bad, the ugly, and the (potentially) good. Science. 355, 1385. 

Sunday, May 21, 2017

Forever Now. Living Life Without a Past

Imagine living every day where you don't remember what happened an hour ago, nor anything that happened to you for all the time before that. Imagine that you can't remember your old friends, even relatives. Imagine that you can't remember what you decided to do anytime in the future.
Lonnie Sue Johnson, a former pilot, commercial artist, and musician, knows what that is like. As told in Michael Lemonick's new arresting new book about her life story, The Perpetual Now, Lonnie Sue experienced a catastrophic herpes simplex viral infection that spread into her brain, almost killed her, and left her with crippling memory failures after she survived. Normally, this virus just causes cold sores, but in a few cases the virus inflames and damages the brain. In Lonnie Sue's case, brain scans revealed that the virus destroyed the part of brain, the hippocampus, that forms past experiences (episodic memory) and general world knowledge (facts, ideas, meaning and concepts—semantic memory).
As she recovered from near death, which took many months, Lonnie Sue gradually recovered some old, well-established memories, like the ability to speak and understand English. She regained her ability to read sheet music and play the viola.
Her memory loss was similar to that of an epilepsy patient, Henry Molaison, known in the brain research literature as "H.M." before he recently died of old age.  The seat of his severe epilepsy was the hippocampus, and surgeons removed it to cure the epilepsy before they knew about the devastating memory loss such surgery would cause. H.M. gladly volunteered for research on his memory loss for many years. Much of what we thought we knew about memory was learned from Henry. The standard model is that there are two kinds of memory, declarative (episodic and semantic) and procedural (motor memories like how to ride a bicycle, play a piano, and the like). The hippocampus is crucial for declarative memories but not procedural ones. At least that is what we thought. Lonnie Sue has revealed that the boundaries between declarative and procedural memories are fuzzy and maybe we don't understand memory as well as we thought.
The comparison with H.M. is not completely parallel. His memory limitations came from an otherwise healthy brain that no longer had a hippocampus. Lonnie Sue may well have had other brain damage than just the hippocampus.
Lonnie Sue, for example, lost many of her procedural memories, such as how to draw and fly a plane. But some of this ability gradually returned. All along she recognized herself in the mirror, and she recognized some old friends even though she couldn't recall anything about them.
Author Lemonick worked with Lonnie Sue and family for some three years as she recovered. His story paints a vivid picture of what life was like for Lonnie Sue and those who cared for her, particularly her devoted sister, Aline, who spent part of every day helping Lonnie Sue take care of herself and cope with the memory problems that never went away.
I admire Lemoncik's ability to explain complex issues of neuroscience in ways that are interesting and easy to understand. Readers will learn quite a bit about brain function from his user-friendly explanations. He even tells of recent studies under way of a very small group of apparently healthy people who have extraordinarily good memory. These people can tell you what happened on every day of their life. But they don't remember everything that happened. Their problem seems to be that certain events every day cannot be forgotten, even decades later. But the real message of the book is the power of love from those who care for Lonnie Sue and her own courage and cheerful spirit in the way she copes with her profound disability.
Lonnie Sue's story compels us to reflect thankfully on our own memory ability that we too often take for granted, with no thought of what life would be like without it. Her story reminds us that the memory of who we have been is an inevitable part of who we are now and who we strive to become. Our memories are not all pleasant, but life without memory of the past would surely be empty.

Lemonick, Michael D. (2016). The Perpetual Now. A Story of Amnesia, Memory, and Love. New York: Doubleday.

Wednesday, May 10, 2017

Genes Change in Your Brain. Do They Change You?

A startling discovery of enormous implication has just been reported in the premier research journal, Science. Despite the accepted dogma that all of a person's cells have the same genetic coding, it turns out that this is not true, especially in neurons. The DNA in each nerve cell (we don't know about sex cells) has hundreds of mutations of the A-T, C-G nucleotides that constitute the genetic code for the neuron. Thus, no two neurons are alike. The study was conducted by 18 research teams at 15 U.S. institutions, formed as a consortium by the National Institute of Mental Health to examine neural genetic coding, using repositories of postmortem brain tissue taken from both healthy people and those with various mental diseases.
The scientists have no explanation at present for what is causing so many mutations and why each neuron has a different genetic profile. The most obvious possibility might seem to be that the mutations occurred as transcription errors during cell division. But there is a major problem with this explanation. We don't know when these mutations occurred. Except for granule cells in the hippocampus and cerebellum, neurons generally do not divide after the first few days after birth. So, if cell division is the cause of mutations, it must be due to what happens during the early post-natal period.
If the mutations occurred sporadically throughout a lifetime, a likely cause for mutation might be DNA damage caused by the free radicals that are generated in ordinary metabolism. Environmental toxins are another possible cause. The point is that the DNA changes are likely to affect how a neuron functions, and that change can last a lifetime.
We know that mutations can cause brain cancer and even certain other brain diseases. The research consortium was commissioned to see if the genetic variants predisposed to neuropsychiatric disease. Obviously, the vast majority of people have these diverse genetic codes in their neurons that do not cause disease. What do they cause? Can the mutations affect which neurons participate in which circuits? Can mutations affect how well you reason, or memorize, or your emotional responsivity? Nobody knows.
A whole new field of research has now been opened. Scientists need to examine different neuronal cell types to see if they are equally affected by mutation. Obvious comparisons needed are between granule cells and all the other neuron types that do not divide.
There is a related aspect that is not considered in this context. That is the likelihood that each neuron differs not only in its genetic code, but also in which genes are expressed. The new field of "epigenetics" has revealed that environmental influences, ranging from drugs, toxins, metabolites, and perhaps even lifestyles can affect the expression of genes, even when there is no mutation. In the case of brain, there is the distinct possibility that one's mental life can affect gene expression. This needs to be studied.
So far, what I have said about gene change and expression refers to single individuals. But what if some of these gene mutations or epigenetic effects that occur in neurons also occur in sex cells? That would mean that traits acquired during one's lifetime could be passed on to future generations. I would hope that the research consortium that has made this monumental discovery about brain cells will extend its charter to also examine sperm and ova.
Recent research on the genetics of the classic animal model of brain function, C. elegans, reveals that epigenetic inheritance of neuronal traits does occur. Gene expression was modified by exposing the animals to high temperatures, and the genetic change was conveyed via both ova and sperm to offspring that had no exposure to high temperature. The epigenetic change was still present some 5-14 generations later.
To the extent that the findings of both of these studies can be extrapolated to humans, we must now consider the possibility that personal lifestyle, environmental, and cultural influences on people may be propagated to successive generations of their children. Bad environments and lifestyle choices may extend well into the future, magnifying the deleterious consequences through multiple generations. We now have to consider that medical and behavioral problems, poverty, and degenerate cultures can arise not only when people make poor choices but that the effects can be genetically propagated to subsequent generations.

These issues may seem to present a challenge to the notion that humans have free will. We are programmed by things that happen to us. But do we not have a choice in deciding much of what we expose ourselves to? The issues are explored in my recent book, Making a Scientific Case for Conscious Agency and Free Will (Academic Press).


McConnell, M. J. et al. (2017).Intersection of diverse neuronal genomes and neuropsychiatric diseases: The brain somatic mosaicism network. Science.  356(6336), 395. doi: 10.1126/scienceaa1641.

Klosin, Adam et al. (2017). Transgenerational transmission of environmental information in C. elegans. Science. 356 (6335), 320-323.