Category Archives: Neuroscience

Default Mode Network

In 1924, an enterprising psychiatrist named Hans Berger discovered a means to record the electrical activity of the brain. Though initially dismissed by his peers, Berger’s findings were validated by British electrophysiologists Edgar Douglas Adrian and B.H.C., Matthews in 1934 and gained widespread recognition in 1938. Berger’s electroencephalography (EEG) remains a cornerstone of modern medicine.

In 1929, Berger published a series of paper in which he postulated that the brain was always active. As evidence, he noted that his device recorded electrical oscillations even when subjects were at rest. Yet again, his contemporaries did not take his findings seriously, holding to a strict belief that the brain activated only in response to a targeted activity or thought. The invention of functional magnetic resonance imaging (fMRI) in 1990 provided the means to challenge conventional wisdom and validate Berger’s hypothesis.

default mode networkAn fMRI detects variances in blood flow across brain regions with blood flow being an established proxy for neural activation. A typical experiment would commence by asking subjects to clear their minds, thereby establishing a baseline metric. Once given a focused mental task, scientists would note which areas of the brain lit up in response. To their surprise, they discovered quite a bit of brain activation in the medial frontoparietal network during the resting state. While it became less active during a targeted task (e.g., generating words), the net increase in brain energy resulting from a task proved relatively small. Understandably, this finding launched a series of inquiries into the nature and function of the newly dubbed default mode network (DMN).

Self-reported data from study participants revealed that their minds wandered when demands to engage the external environment relaxed. They thought about past events or future goals and experiences. They daydreamed. They reflected on personal relationships and how they impacted their lives. These findings prompted American psychiatrist, neuroscientist, and author Judson Brewer to describe the DMN as a “narrative network” because it is caught up in self-referential processing, a.k.a. “the story of me.”

Drs. Matthew Killingsworth and Daniel Gilbert explored the frequency with which the DMN activates during waking hours. They gathered a group of test subjects with Smartphones and pinged them randomly throughout the day to capture what they were thinking and doing. It turned out that people engaged in the kind of spontaneous mind wandering associated with the DMN about as much as they were attentive to what was actually happening around them. Moreover, mind wandering was prevalent during all kinds of activities. And here’s the kicker: this behavior pattern did not make them happy.

As noted in an earlier post summarizing Dr. Mihaly Csíkszentmihályi’s book Flow: The Psychology of Optimal Experience, we are happiest when fully engrossed in voluntary activities that stretch our bodies and/or minds to accomplish something worthwhile. Such engagements take us out of “the story of me” and immerse us in a broader narrative that unfolds moment-to-moment. The DMN reasserts itself to the extent that we become bored or distracted.

Much like “flow,” Judson Brewer’s lab has shown that mindfulness meditation correlates with decreased DMN activity, notably in the posterior cingulate cortex. This effect can be induced with a relaxed focus on the breath and disrupted by distraction, a wandering mind, and trying too hard to be mindful.

Experienced meditators evidence less DMN activation and greater happiness than novices. That alone piques my interest. But I’ve surfaced another motivation to become a relaxed, proficient, consistent mindfulness practitioner. Sleep-onset insomnia has dogged me for most of my life. My head hits the pillow, and my brain starts thinking thoughts spontaneously. It can go on for hours. I now understand this phenomenon to be the inner working of my DMN. As such, I’ve started experimenting with mindfulness meditation as a bedtime routine to see if I can make a dent in my sleeplessness. The happiness boost from a less energized DMN combined with a rested body could be sheer delight.

Thoughts We Think Per Day

neural network

At a talk I attended recently, the speaker posited that the average person thinks tens of thousands of thoughts per day of which 95% are the same as the day before. My experience aligns somewhat with incessant repetition, but I took issue with a mind that conjured up a new thought every couple of seconds. Moreover, I wondered: How in the world would someone measure the frequency and content of thoughts scientifically? Time for a little research…

Early attempts at thought measurement relied upon self-reporting. Presumably, subjects kept a tally every time they found themselves thinking a thought and marked whether it was a novel one. Of course, the very act of interrupting a thought for reporting purposes would disrupt the brain’s natural processes. And I suspect that such reports were not entirely reliable.

With the advent of functional magnetic resonance imaging (fMRI) technology, scientists gained the ability to detect patterns in brain network activation and tie them to discrete objects (e.g., faces, houses). Not surprisingly, it takes a lot of work and a chunk of change to map the thought pattern for each object. Given the mind-boggling number of objects in the world, the current database proves woefully incomplete to track what people think. Moreover, the complexity of mapping thought patterns ratchets up considerably given that each thought also reflects the subject’s relationship to the object – e.g., perceiving, believing, fearing, imagining, remembering. So, I don’t place much weight in aforementioned speaker’s characterization of our daily thought patterns.

I managed to stumble upon a report by Dr. Jordan Poppenk and his research assistant Julie Tseng from the Centre for Neuroscience Studies in Queen’s University, Kingston, ON opted that gave me something solid on which to stand. They eschewed concerns about what people think in favor of determining the frequency with which subjects transition from one thought to the next (a.k.a. their mentation rate). It turns out that this inquiry can be measured reliably using fMRI data. They published their methodology and findings in the July 2020 issue of Nature Communications.1 Though I found the text rather dense scientifically, I’ll try to explain in simple terms what I think it says.

Poppenk and Tseng’s scientific progenitors took fMRI scans on subjects as they watched well-crafted movies. Participants displayed similar brain activity patterns in widespread low- and higher-order areas. These studies showed how movies exert control over our cognitive states and identified the associated neural circuitry. Poppenk and Tseng suggested that a similar mechanism existed for spontaneous thought. They reasoned that both activities involve a shift in focal point during which new information integrates with existing representations to move a storyline forward.

They analyzed fMRI data from 184 participants taken while watching a movie and at rest. They used the latter to distinguish random fragments of neural activity from contiguous, worm-like segments that arose in response to an attractor (or focal point) that stabilized neural network configurations. Having developed the means to map and measure thought worms2 for minds at rest, they applied their methodology to the fMRI data associated with movie watching. They verified that their worm-like constructs held psychological relevance. They also validated the hypothesis that a mind at rest displays the same thought architecture as a mind in a stimulus-controlled environment. As they stated in scientific jargon:

“Based on the centrality of semantics to thought, we argue these transitions serve as general, implicit neurobiological markers of new thoughts, and that their frequency, which is stable across contexts, approximates participants’ mentation rate.”

Poppenk and Tseng measured the average median thought transition rate across movie-viewing and at rest to be 6.5 transitions per minute. Assuming an 8-hour sleep cycle, that corelates to over six thousand thoughts per day. They also detected higher mentation rates for persons associated with neuroses. That finding is consistent with such individual’s susceptibility to distraction and excessive self-generated thoughts.

While advancing knowledge of the erstwhile mysterious brain, Poppenk and Tseng advocate for additional research to explore and build on their findings. Beyond satisfying intellectual curiosity, their research could lead to early detection of neurosis, schizophrenia, ADHD, etc. and open up the possibility of accelerated life-enhancing intervention.

Notes:

1 See article entitled “Brain meta-state transitions demarcate thoughts across task contexts exposing the mental noise of trait neuroticism” at https://www.nature.com/articles/s41467-020-17255-9.
2 Thought worms are adjacent points in a simplified representation of activity patterns in the brain. They reflect consecutive moments when a person focuses on an idea.

The Distracted Mind

With a looming deadline for a project, I like to clear my calendar, shut off the phones, and hide out in my office until the job is done. It’s my way of creating space for concentrated attention. Yet despite good intentions, I’m not always successful:

  • A random noise can wiggle into my ear and prompt me to investigate its source.
  • I might catch my name and wander what is being said.
  • My mind may wander or start fussing about something completely unrelated to the work at hand.
  • I may start thinking about the email or text messages that I’m missing and grab my phone to satisfy my curiosity.
  • Someone may interrupt my work to deal with an important matter.

With each interruption, I lose my train of thought and have to spend a bit of time getting back on track. It forces me to spend more time on task than I’d budgeted and may affect the quality of my work. Drs. Adam Gazzaley and Larry D. Rosen explore this all-too-common human foible in The Distracted Mind: Ancient Brains in a High Tech World.

As documented in prior posts, human cognition has evolved across the millennia to keep us alive. It allocates our finite processing capacity efficiently and effectively:

  • Amidst an ocean of stimuli, we can focus our attention like a spotlight. We determine which senses, spaces, or objects merit perception and action and which ones to ignore. Suppressing irrelevant data yields higher quality representations of the areas of focus.
  • We’re equipped with working memory to hold information active for brief periods of time. It serves as a bridge between current perceptions and future actions and functions best when unencumbered by distraction.
  • We can engage in task switching to manage multiple goals at the same time. Though we may harbor the illusion of parallel processing, our human brains only operate on one thing at a time even when competing tasks do not demand use of the same cognitive controls.

Our prefrontal cortex manages cognitive capacity in service of goal setting and enactment. It excels in evaluation, reasoning, decision making, organization, and planning. Once a direction has been set, it manages our attention, working memory, and task management systems to reach the destination. Extensive connections between the prefrontal cortex and all other brain regions enable continuous processing of sensory, emotional, and motor functions.

Sleep deprivation, stress, and intoxication downregulate our capacity for focused attention. We also lose this facility as we age. While we retain the capacity to direct our cognitive “spotlights,” we’re slow on the draw to weed out distractions. We give them leave to generate internal interference and mess with our working memory. We’re also less effective at task switching.

While distractions and interruptions get in the way of forward progress at any age, both evolved as essential survivalist instincts. When wandering the jungles seeking food or shelter, our ancestors needed to be alert to environmental changes that might signal a threat – the hissing or rattling of a poisonous snake, or the rustling of bushes as a predator nears. Those who were adept at sensing and reacting to new information moved quickly to protect themselves; the others likely perished. The Darwinian victors were also attuned to input that might lead to food, water, or other forms of gratification.

Unfortunately, the jungle in which we find ourselves today presents a gaggle of distractions that have no material bearing on our survival. Email, text, social media, and news alerts constantly vie for our attention. Seventy-five percent of us operate within 5 feet of our phones day and night; 80% of us reach for our phones upon awakening. Forty-one percent of us respond to email and 71% to text ASAP. We expect rapid respond and feel rebuffed when it is not forthcoming. It should come as no surprise that young adults task switch 27x per hour; older adults task switch 17x per hour. This elevated distractibility increases working hours, stress, frustration, time pressure, and effort. So why do we do it?

The human brain craves novelty; we’re driven to seek new information. When consigned to a single task, we may grow bored with what we’re doing and look for something to entertain us. We may get anxious to move on and start thinking about the next thing. We may experience FOMO (Fear Of Missing Out) and grab our phones to check on the latest news. We may tell ourselves that we have to respond to every alert. All such distractions and interruptions make us far less effective at managing our lives and the goals to which we have committed.

Recognizing the cost of unwanted distraction, the authors provide a bevy of behavioral adjustments to minimize them.

  • Focus on one project at a time in a distraction-free environment. Put away nonessential work materials – i.e., clear your desk! Limit yourself to one screen and close irrelevant apps.
  • Eliminate email, text, news, and other alerts. Set expectations for response times with family, friends, and colleagues.
  • Interleave periods of standing and sitting while working on the project.
  • Schedule brief breaks every 45-90 minutes to relieve boredom. Options include: exercise, work in the garden, daydream, take a power nap, have a snack, read a chapter of your book, laugh.

Beyond the foregoing behavioral modifications, the authors also provide recommendations for enhancing cognitive control:

  • Meditation trains the mind in focused attention and open monitoring of thoughts and feelings. Practitioners learn to acknowledge the latter and dismiss them rapidly. Meditation has been shown to improve sustained attention, processing speed, and working memory.
  • Computerized cognitive exercises adaptively challenge specific areas of cognitive capacity causing them to become stronger over time. As a case in point, Akili Interactive offers digital therapeutics to improve cognitive function. Their offerings were developing in collaboration with world renowned neuroscientists.
  • Judicial use of video games can also have a positive impact on attentional capacity, distributed attention, and speed of attentional processing. They’re demanding, adaptive, and fun!
  • Exercise! A steady diet of aerobics and strength training increases brain volume, nerve growth factors, blood flow, functional and structural connections, and neurogenesis.

Placebos, Nocebos, and Hypnosis

“A mind is fundamentally an anticipator, an expectation-generator.” – Daniel Dennett, AI pioneer

In 1978, a young couple faced a crisis of conscience. As practicing Christian Scientists, they believed in the power of faith healing and eschewed modern medicine, but their infant son was gravely ill. With his life in the balance, the mother considered taking him to the hospital. Her Christian Science healer reminded her of God’s love for the boy and encouraged her to hold fast to her faith. Moments later, the boy’s condition turned around.

That young lad (Erik Vance) heard the story of his miraculous salvation many, many times during his formative years in the Christian Science community. Faith healing was the only form of medicine that he knew, and he witnessed its beneficial effects time and again. Though he eventually fell away from the church, his fascination with the practice stayed with him. He became a science writer and traveled the world to understand the physiological underpinnings of this seemingly magical phenomenon. He captured his findings in Suggestible You: The Curious Science of Your Brain’s Ability to Deceive, Transform, and Heal.

As noted in prior posts, our minds are not computers rooted in logic and facts. They are survival machines geared toward keeping us alive as efficiently and effectively as possible. Expectation serves as a primal survival skill – i.e., anticipating what lies in the immediate future and mounting a swift reaction. Experience guides our expectations. When missing information, we fill in the gaps and move forward, sometimes outside of conscious awareness.

placebo, noceboExpectation plays a substantive role in the body’s capacity for healing. When ill or injured, most of us have been trained to trust in medical professionals to make us well. In the Western world, we visit clinics where caregivers in scrubs and/or white lab coats discuss our ailments and then prescribe drugs, shots, or procedures to make us well. But it turns out that for certain conditions, we can generate the same degree of healing with sham medications and procedures. Scientists refer to that phenomenon as the placebo effect. So, why does it work?

Our brains are adept at pattern recognition; it feeds our “expectation-generator.” Famed neuroscientist Ivan Pavlov explored this capacity in canines by ringing a bell every time he offered them food. Pretty soon, the dogs would salivate whenever they heard the bell. Humans also experience conditioned responses. In one experiment, test subjects were given an immunosuppressant drug in a sweet drink to lower their immune response. After a few iterations, their bodies produced the same reduction in immune response with out the drug even though participants were told in advance that their drinks contained no pharmaceuticals!

Our brains can induce a gaggle of physiological responses without prescription drugs. We’re walking pharmacies with the capacity to produce effective treatments for certain conditions – notably, pain, anxiety, depression, irritable bowel, addiction, nausea, insomnia, and Parkinson’s disease. But several factors influence this healing effect:

  • We need conditioning, a credible backstory, and appropriate environmental cues to engender a belief in the treatment. [Note: Placebo injections prove more effective than placebo pills because we believe that they are more powerful. Likewise, sham surgeries work better than sham pills.]
  • We need a favorable emotional response to our circumstances. Hope yields positive results; despair exaggerates suffering.
  • Social pressure can lessen symptoms or speed recovery – e.g., “If it works for millions of people, it’ll probably work for me.” In fact, the peer pressure placebo effect is twice as strong as an individual placebo response. It feeds into our primal need to go along with the herd.
  • Our genetic maps may make us more (or less) susceptible to placebo responses. As a case in point, folks with the met/met variation of COMT (which, among other things, sweeps up excess dopamine) are far more placebo sensitive than those with the val/val or val/met variations.

Unfortunately, a susceptible brain can make bad things occur without cause – a.k.a., the nocebo effect. One’s mental state can cause physiological suffering. It’s generally driven by fear and can be initiated with a few well-placed words – a report of a contagious disease, a belief that one’s misdeeds will engender cosmic revenge, a curse levied by a supernatural being. A wise person blocks all aggressive suggestions that could cause harm.

Hypnosis represents another form of suggestibility that can drive real physiological change. Its efficacy relies upon the skill of the hypnotist in painting a picture of the magical place that relaxes the participant and opens the door to suggestion, using appropriate pacing and tone of voice to sustain the “trance,” and implanting a credible story that sticks. Roughly 10% of the population responds strongly to hypnosis. Early evidence suggests these folks have naturally higher theta and alpha brain waves than their busy-minded beta and gamma brain-waved counterparts. The latter benefit from meditation to calm their “monkey minds.”

So, what should we make of all of this?

Vance asserts that expectation and suggestibility are a part of all forms of healing. As he says; “Everyone’s door to expectation has a different key, and everyone is suggestible in a slightly different way. But once the door is unlocked, we have amazing power to heal ourselves.” His guideposts for leveraging this capability:

  • Don’t endanger yourself. While some maladies may respond to self-healing, take advantage of modern medicine when you need it.
  • Don’t go broke. Be sensible and follow the evidence before emptying your wallet.
  • Don’t send any creature to extinction no matter how compelling the backstory. They have a right to live, and their sacrifice may do no material good.
  • Know thyself. “For most, suggestibility is a cocktail of genetics, personal beliefs, experience, and personality.” Figure out which pathways hold the most promise for you and be open to the power they hold

Pain and the Brain

“Pain is an opinion on the organism’s state of health rather than a mere reflexive response.” – Dr. V. S. Ramachandran, neuroscientist

headacheMost of us have experienced the body’s diverse repertoire of physical pain. Burning. Aching. Throbbing. Take-your-breath-away stabbing. Agony. Nuisance headaches. Debilitating migraines. Nausea. Feverish discomfort. I could go on, but just thinking about it makes me feel bad. For indeed, emotional suffering generally goes along with pain. Given its unpleasantness, there’s good reason to learn about how it works.

Before reading Dr. Norman Doidge’s The Brain That Changes Itself, I tended to side with the argument that pain was a reflexive response. If the body was sick, hurt, or otherwise debilitated, we were going to have pain. End of story. But it turns out that the brain has far more to do with our experience of pain than I realized.

Our bodies are chock full or neurons that sense injury or illness and report findings to the brain. This feedback provides the opportunity to mobilize resources to initiative repair, fight infection, and take other action to promote healing (e.g., rest). However, these pain signals go through gates; the brain decides whether or not to let them through.

Traditional herbalists and modern medicine have given us remedies to dampen our physiological experience of pain. Thank goodness! But it turns out that the brain can be tricked into lowering its pain response regions when harboring the belief that medication has been administered. Subjects have experienced pain relief when given placebos in lieu of drugs.

Unfortunately, the brain’s “pain map” can get disordered and cause us to experience pain even when no physical threat is present. Amputees often report feeling discomfort at the site of absent limbs. Patients experience “learned pain” when immobilizing muscles in response to injury and then attempting movement again. The “pain wiring” persists even when the body part is no longer subject to trauma. Fortunately, innovative neuroscientists figured out how to use mirror boxes and mental imaging to help the brain see fully healed body parts and release the pain response.

Why does this happen? The brain relies upon a feedback loop to activate and deactivate its pain response. When the signaling gets out of sync, we can get stuck in a cycle of pain. In addition, the neurons in the pain system are quite plastic. Chronic pain can cause them to fire more easily, thereby exaggerating their signals. It’s why we’re often told to “get ahead of the power curve” with pain medication before these neurons get a little too good at firing. Pain killers before surgery may also prevent undue plastic change in the pain map.

For those of us who’d prefer to avoid medication for pain management, acupuncture may be an option. It purports to inhibit pain, close the pain gates, and block pain perception. It also claims to release endorphins, increase blood flow, and induce muscle relaxation. I’ve never used it for pain relief but have found the experience quite restful and restorative.

Meditation may also be a means to relieve discomfort naturally. When bringing attention to an aching body part, we can gain some emotional distance from the experience while exploring the nature of the sensation. While it may or may not diminish the physical experience, it can certainly help mitigate our emotional response.

Why We’ve Taken Up Square Dancing

My opening post on Norman Doidge’s book The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Neuroscience was intended to inspire readers to become lifelong learners for the sake of sustaining healthy brains. Having witnessed firsthand my father’s struggle with dementia and my mother’s Alzheimer’s disease, I’m quite serious about cognitive exercise. My husband is on that bandwagon, too. Square dancing has become our latest adventure.

Square dancing came to America with European settlers and originally took the form of memorized sequences of steps. When African slaves provided music for dances, they began calling out the steps, a practice that became commonplace by the early 1900s. Beginning in the 1930s, an educator by the name of Lloyd Shaw codified the steps and calls to make the dance more accessible to new dancers. It gained in popularity between the 1940s and 1960s, gaining a boost with the folk music revolution.

Here’s how it works:

A square dance involves four couples arranged in a square facing the middle of the square with one couple on each side. A caller provides instructions from a standard collection of roughly 70 moves to which the dancers respond. The moves have variations that can be invoked from a variety of formations. Most calls take between 4 and 32 beats. The caller may provide the instructions as an overlay to a lively instrumental piece or may work them into a vocal performance of a given tune. In either case, dancers must be on alert to hear the calls, watch their fellow dancers, and execute the correct steps.

square dancingMy husband and I had some exposure to square dancing as grammar school students, but that was a LONG time ago. Fortunately, the local area’s square dancing clubs offer a series of 10 lessons covering the basics. Their members volunteer as “angels” to help the newbies get acquainted with the calls and moves. These experienced dancers model the correct form and provide gentle nudges and tugs to help us get in the right places at the right times.

Even though I’ve had a fair bit of dance training and am a reasonably quick study, I really have to pay attention to figure out what’s coming next and remember what I’m supposed to do. I’ve also found that I need to do a little bit of homework between classes to reinforce what I have learned. Fortunately, there’s a great on-line tool called “Taminations” that provides written instructions and animations to help me visualize the steps and my parts in them. Hats off to my husband for whom this exercise is a lot more challenging!

So why do I think square dancing is good for cognitive health?

Dr. Sanjay Gupta identified five key factors that contribute to a healthy brain: exercise, learning, sleep, diet, and socialization. Square dancing ticks off three of the five boxes. Dancing in any form involves movement, and square dancing is no exception. Classes and scheduled dances generally last 2 hours with just a few short breaks to catch a breath and chat. As noted earlier, this particular form of dance demands careful attention to receive and act on the latest instruction. While particularly challenging for newbies, it continues to demand concentration even for those who’ve been dancing for years. And we’ve found the square dancing community to be warm and welcoming – a very good resource for social connection!

The Changeable Brain

“We are all born with a far more adaptable, all-purpose, opportunistic, brain than we have understood.” – Dr. Norman Doidge, MD

I’ve explored aspects of neuroscience in prior blog posts. My latest foray into the subject came through Norman Doidge’s book The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Neuroscience. What I learned from his research made me all the more impressed by this amazing little organ.

cerebral lobesMost of realize that our brains are the master controllers for sustaining bodily functions, processing sensory input, and incubating consciousness. Yet we may not grasp the extent to which the brain alters its structure and function in response to thoughts, activities, and environmental factors. Scientists refer to this phenomenon as neuroplasticity – i.e., the neural network’s ability to change through growth and reorganization. Through it, we can improve mental activities, heal from injury, and establish robust routing systems that bypass blocked pathways as the need arises. With attentive effort, we can sustain this remarkable capacity to the end of our days.

Much like physical fitness regimens, stimulating the brain makes it grow. Brain weight may increase up to 5% through mental training or life in enriched environments; targeted areas may increase up to 9%. This weight gain finds expression in stimulated neurons that increase in size, develop 25% more neural connections, and command increased blood supply. These “beefy neurons” become more efficient, taking less time and resource to perform tasks for which they’ve been trained. Powerful signals have greater impact on the brain.

A leading researcher on neuroplasticity, Dr. Michael Merzenich proved that substantive improvement in cognitive function is possible at any age. The key to success lies in giving the brain the right stimuli in the right order at the right time to drive plastic change. He says:

“When learning occurs in a way consistent with the laws that govern brain plasticity, the mental ‘machinery’ of the brain can be improved so that we learn and perceive with greater precision, speed, and retention.”

For example, through use of specially designed computer programs, users receive specific challenges that target their developmental needs and add difficulty at a pace consistent with their learning styles. Struggling learners at school may take advantage of Fast ForWord, an evidence-based, adaptive reading and language program that boasts 1-2 year gains in 40-60 hours of use. Merzenich’s BrainHQ offers 29 exercises that address attention, brain speed, memory, people skills, navigation, and intelligence.

Brain maps are neither static nor universal; we allocate neural capacity competitively. If one area goes dormant, another area will take it over. As such, if we stop using a skill, that brain map space will be placed in service of an active skill. It’s the law of the jungle: use it, or lose it. For example, a blind person cannot use the visual cortex to receive input from the eyes. That processing power may be repurposed to provide heightened sensitivity in hearing and touch. Unfortunately, if we stop exercising our analytical skills or creative capacities in favor of mindless activities, those vital cognitive resources will also be repurposed. Once a bad habit claims (and sustains) brain space, it can be difficult to dislodge.

The brain can reorganize itself after devastating injury so long as there is adjacent, healthy tissue that can be recruited to take over for lost function. Treatment must address both neural shock and learned nonuse. To that end, motivated patients put themselves through a series of physical and cognitive efforts to support their brains’ rewiring. Legendary actor Kirk Douglas famously worked his way back from his 1996 stroke and continued to act and publish. Actor Christopher Reeve regained a modicum of feeling and movement after sustaining a paralyzing spinal cord injury.

So why do so many of us lose brain function as we age?

Give the right combination of stimuli and experience, we are learning sponges throughout our childhood and teen years. As we grow into adulthood, we lean more heavily on mastered skills in lieu of acquiring new ones. By middle age, we’re settled into our careers and rarely engage in the kind of focused attention that produces long-term neural growth. In a word, we’re comfortable.

We’re also prone to be far less active physically than when we were young. Physical exercise elevates brain-derived neurotropic factor (BNDF), a substance that starts to wane as we age. BDNF plays a crucial role in neuroplastic changes by:

  • Consolidating neural connections
  • Promoting fatty growth around neurons to speed transmission times
  • Helping the brain pay attention (and remember) through nucleus basalis activation

So, if you’d like to hang on to what you’ve got (or add to it), be prepared to challenge yourself throughout your life. Activities that involve deep concentration – e.g., reading/studying, learning a new language, developing proficiency on a musical instrument, playing complex board games, taking up dancing – have been associated with a lower risk of dementia. Effective use of imagination also helps. If hesitant to take action (or temporarily constrained to do so), visualize the activity in attentive detail. It strengthens the cognitive muscles and increases the speed at which you can attain competency when taking action.

Forecasting Future Happiness

crystal ballIn Stumbling on Happiness, Daniel Gilbert asserts that choices we make today carry an expectation of benefitting our future selves. After all, we’d like to set up our older incarnations for happiness. In fact, researchers tell us that we spend on average 12% of our waking hours thinking about the future. But are we really any good at anticipating our future tastes, preferences, needs, and desires?

Gilbert’s answer: NO. He uses neuroscience to make the case that we consistently misremember the past, misperceive the present, and misimagine the future. In short, we’re not terribly well connected to reality, and our crystal balls are hazy at best.

We don’t store memories as if they’re live action films with every shot recorded. If we did, we’d need really huge brains! Rather, each stored memory engram captures a few critical threads and small sets of key features. Upon retrieving the memory, our brains quickly “reweave the fabric” to give the illusion of an accurate record and fill in the details under the radar. Our recall of emotional states tends to be weighted heavily toward our sensibilities during the closing moments and theories about how we must have felt. And memories change ever so slightly every time they are retrieved and then stored again.

This bit of “brain magic” applies in the present, too. We fill in gaps in our visual fields in places where our optic nerves would otherwise leave a blind spot. And what we see gets colored by what we already think, feel, know, want, and believe. We interpret the world as much as experience it. Thus, two people witnessing the same scene can have quite different accounts of what happened.

We make the same cognitive error when imagining the future. When a friend invites us to a party, we fill in the gaps on all of the information that isn’t provided – what it will be like, how we’ll feel when there, what the energy in the space might be. And the further our imaginations stretch into the future, the fewer details we’ll register.

We have a very strong bias toward the present. It colors our remembered past and thoroughly infuses our imagined futures. For instance, we can’t feel good about an imaginary future while feeling lousy about a present circumstance. And even when the present is relatively rosy, we’re just not adept at walking in our future selves’ shoes:

  • We pay more attention to favorable information, surround ourselves with folks who provide it, and accept it uncritically. This filtered input does not provide a realistic view of the past, present, or future.
  • The comparisons we make now (and which influence our choices) may not matter to us in the future. We fail to acknowledge that we’ll think differently as we age an accumulate life experience.
  • We don’t forecast our hungers accurately – for food, emotional support, social connection, intellectual stimulation, or sex. We really can’t imagine how we’ll feel.
  • Negative events don’t affect us as badly (or for as long) as we think. Our psychological immune system mitigates against unhappiness by helping us find silver linings and effective action. It also helps us craft narratives that diminish emotional pain.
  • When considering the past to foretell the future, we remember the best of times and the worst of times… but not the most likely of times. Unusual events come to mind easily, so we tend to think that they’re more common than they really are.

So, if we’re not very good at predicting our futures, to whom or what should we turn to for our “crystal balls”? Gilbert suggests that we talk to people who are currently living in the state that we might imagine for our futures. Studies have shown that such “surrogates” provide a far better indicator of our future emotional well-being than the portraits our imaginations paint. Unfortunately, few of us act on that advice as we consider our experiences and vantage points to be so distinct from everyone else as to render such feedback useless. But the truth of the matter is that we’d profit from their insights.

One other piece of sound advice… When weighing the choice between action and inaction, lean toward action. Nine out of 10 folks regret not have done things more than the things they did. Moreover, our psychological immune system has an easier time rationalizing an excess of courage than a surge of cowardice.

Cognitive Error

Last week, I shared some insights regarding memory from Dr. Catherine Sanderson’s Introduction to Psychology. As she points out, our memories are not nearly as good as we think they are. It’s also the case that our powers of discernment and problem-solving skills are not all that ship-shape. Here are a few ways that we tend to go wrong:

mistakeOverreliance on Intuition: “Gut instincts” serve us well when our survival depends upon the ability to make and commit to a course of action quickly. They’re also helpful when providing a “sixth sense” that something demands our considered attention. However, sometimes snap judgments are flat-out wrong.

Confirmation Bias: Even when we slow things down and give an issue our due consideration, we have a tendency to pay attention to data that affirms our earliest sensibilities and ignore information that does not fit our preconceptions.

Fixation: When we become rooted into one way of thinking, we can find it difficult to see a circumstance or problem with new eyes – e.g., doggedly searching the same place for our house keys even though they’re clearly not there.

Functional Fixedness: We may perceive a person, issue, object, or circumstance as fixed and unchanging. We aren’t open to new information or new approaches – e.g., insisting upon using a screwdriver instead of making do with a dime, nail file, or knife.

Availability Bias: We perceive an event as more likely to occur if it more readily comes to mind. For example, we may forego air travel for fear of death by plane crash (a 1 in 11 million chance per annum) as a function of the harrowing publicity that accompanies air traffic accidents. Yet we don’t worry so much about motor vehicle accidents for which our risk of death is 1 in 5,000 annually.

Stereotypes: When a superficial description fits a preconceived rubric, we make mental short-cut and fill in the blanks with our stereotypes rather than let the page stay blank and fill it in with the new experience. Racial, gender, and cultural biases top this list.

Representation Bias: Wording affects our perceptions. We feel good about consuming something that is 95% fat-free without stopping to consider that it’s actually 5% fat. Likewise, an item purchased for $19.99 feels like more of a bargain versus one price at $20.00. And, as folks approach a milestone birthday – say, 80 – they’ll confidently state that they’re in their 70s the day before even though they’ve clearly lived 80 years already!

Overconfidence: We tend to overemphasize our known knowns, down regulate our known unknowns, and outright dismiss our unknown unknowns. This phenomenon comes to the fore among groups whose participants share similar views and come together under a strong leader. Their belief in the power of collective judgment fails to recognize the inherent aversion to outside perspectives and the social pressure to conform.

Dr. Sanderson ends the lecture with a message of hope. We can overcome our vulnerability to error by recognizing our affinity for shortcuts and opening our minds to possibilities. Helpful strategies include:

  • Slowing down and enjoying the exploration.
  • Actively seeking out persons with different perspectives and listening attentively to their views
  • Encouraging dissenters to speak up and welcoming their full-throated participation
  • Choosing leaders who take seriously the mantle to draw everyone out

Memory

Ever since I watched Dr. Sam Wang’s 36-part educational series entitled Neuroscience of Everyday Life, I’ve been fascinated with the brain. I’ve done additional research and written a few blog posts on the subject. This week’s installment on memory comes courtesy of Dr. Catherine Sanderson and her series entitled Introduction to Psychology.

memoryMost of us think that our memory processing works like a computer. We receive input through our five senses, we encode the data, and we place it in storage. When we want to retrieve the data, we go back into our data repository and pull it back up. While we might admit that we don’t quite capture or retain all of the data, we generally believe that the parts we store accurately reflect the source data.

The truth of the matter is that memory is a constructive process. As discussed in an earlier post, memories get stored in shorthand based on what the brain considers important. In particular, we pay attention to certain bits of data and ignore the rest. There’s also good evidence that we erase and re-write our memories every time we recall them, often changing them in the process. And, we invent details to fill in the gaps and create a more coherent story.

Of all of the memories that we might think we’d retain accurately, those related to major life events would top the list. Dr. Sanderson refers to them as “flashbulb memories” – e.g., where you were and what was happening when the twin towers fell on 9/11. Yet even those memories are subject to change, in part because we tend to process them a lot. And with each recall, we make subtle changes to the story arc. At first, we might get a twinge to suggest that something isn’t quite right. Over time, those small adjustments become entrenched. As my father used to say about one of my relatives: “The first time she tells a lie, she knows she’s made it up. The second time she tells it, she’s believes it’s true because she has heard it before.”

Here are a few other factors that put a monkey wrench into our total recall:

  • Memories fade over time, especially when they lack periodic reinforcement (a.k.a., the Decay Theory).
  • Similar memories compete with one another when vying for our attention (a.k.a., the Interference Theory). With proactive interference, old stuff interferes with our ability to learn new stuff. With retroactive interference, new stuff interferes with our ability to remember old stuff.
  • We remember some piece of information, but we don’t remember where we picked it up (a.k.a., Source Amnesia). This issue can prove troubling in the medical or political realm because we can be manipulated into believing false information.
  • We block out information that we don’t want to remember (a.k.a., Motivated Forgetting) – e.g., how much buttered popcorn we ate while watching TV.

Based on our current understanding of neuroscience, Dr. Sanderson offers the following advice for those who’d like to improve memory:

  • Chunk it. When tasked with learning (or memorizing) something new, break the information down into manageable units. Focus on processing a chunk at a time.
  • Create retrieval cues. Exercise your creatively to come up with devices that help you retrieve information. Use acronyms or clever phrases to prod memory. For example, musicians use the phrase “Father Cooks Good Dinner Always” to remember the order in which sharps appear in a key signature (F, C, G, D, A).
  • Organize it. Create an outline to identify the major points and the associated details. Focus on the major points first and create a memory structure to solidify them.
  • Repeat it over and over. Studies show consistently that we do best when breaking up our study periods into multiple sessions and reviewing content at each session. By contrast, cramming is an ineffective way to learn. We’re handicapped in the moment, and our long-term retention suffers mightily.
  • Focus on it. Really pay attention to what you’re doing when learning something new. Stop multitasking. Bring your full senses to bear on the task.

One final little tidbit from Dr. Sanderson: Our most vivid life memories form between the ages of 15 and 30 because that’s when many of our first-time life events occur. Perhaps those of us on the far side of 30 should try squeezing in a few novel experiences!