Photo credit: Andrew Ostrovsky
Dreams provide an observation window to our memory consolidation, long-term memory formation, and synaptic development process. Dreams rearrange discrete and unconsolidated memories to tell a story. Dreams are subject to the same "story-telling" evolutionary instinct as our naturally occurring cognitive biases. Reaching the dream state is an indication our thinking maintenance process is healthy.
To build our dream perspective, this article starts with a description of how we think. From there, we explore why we sleep as support for our thinking processes. Finally, we build on our thinking and sleeping understanding to describe our dream perspective. This article builds on context from neuroscience and psychology. Several examples and "digging deeper" resources are provided along the way.
As a starting point, sleeping is an important input to the thinking maintenance process, with dreams providing an observation window into that process. But dreaming is not just a thinking process bystander. Dreaming is like the proverbial "canary in the coal mine." Not reaching a dream state suggests there is a thinking process problem. Not to worry, just because we do not remember our dreams, does not mean the thinking maintenance process did not occur.
In this article, we build an understanding of why our thinking maintenance process requires sleep, including disease and related impacts resulting from not having proper sleep hygiene. We then present and explore our dream perspective, including how dreams are subject to the same evolutionary instincts as our story-telling cognitive biases. Along the way, we provide suggestions for activating your healthy brain.
Table of Contents:
Introduction
Thinking
Sleeping
Dreaming
Dream summary and conclusion
Notes
Extras - Deeper dives, Examples, and Analogies:
Brain biology deeper dive
The Flow State paradox
Align higher education with how we think
Building memory by building many synaptic connections
Cramming for an exam - A counterproductive memory development example
A cognitive bias and reasoning error analogy
These are extra resources intended to help deepen your understanding and pique your curiosity.
2. Thinking
The brain is an extraordinary and complex organ. People are born with about 100 billion neurons. Consider neurons as microscopic buckets holding and switching biochemically activated electric signals. The neuron's biological "thinking partner" is called the "synapse." At birth and especially earlier in life, we generate approximately 100 trillion synapses. [i] Think of synapses as the network lines that connect the buckets. Together, neurons and synapses are the building blocks for thought, like putting together a sentence or completing a math problem. The basis for learning is the creation of new synaptic connections. This is known as neuroplasticity. Also, while the rest of your body will weaken as you age, neuroplasticity enables a healthy brain to strengthen throughout one’s life, all the way until one dies. In fact, many philosophers and scientists relate learning to life itself.
“Wisdom is not a product of schooling but of the lifelong attempt to acquire it.”
- Albert Einstein
“No problem can withstand the assault of sustained thinking.”
- Voltaire
This article challenges the notion that you "can't teach an old dog new tricks." We suggest that with the proper behavioral strategies, "old dogs" or younger folks are quite capable of increasing synapses, enhancing our smart-defining cognition, and outrunning potential naturally occurring cognitive challenges. [ii]
Throughout this article, we will discuss approaches to encourage neuroplasticity and healthy brain habits. This helps maintain a robust brain that will serve us well to the end of our days.
Let us start with a simple exercise - try writing your name with the opposite hand from which you normally write. It will likely feel odd to hold the pen in your offhand. Then writing itself will take much concentration. Every letter will need to be considered. You will likely be disappointed with the quality of the penmanship. Next, write your name with your offhand 10 times in a column on a single sheet of paper. Notice that each time you write your name it gets a little quicker and the quality increases. This is neuroplasticity in action! You are quite literally enabling new synaptic connections by learning something new. Learning to write well with your offhand will take significantly more practice, over many weeks. In the next section of the article, we will describe the process by which your brain learns and improves via synaptic growth. By the way, many neuroscientists believe we may decrease the chances of being affected by brain disease by ongoing synaptic growth. [iii] So, learning something new on a regular basis will help you outrun brain disease!
You spend much of your waking day processing information. Like the offhand writing example, some of your daily processing includes new, synaptic growth-based information. However, most of your mental processing occurs along existing synaptic pathways. Take driving as an example. For an experienced driver, driving “feels” very easy. They have practiced this activity so much that the neural pathways have become deeply habituated. Thus, while "thinking about driving" is occurring, it feels easy, almost automatic. The act of driving is mentally executed on highly habituated mental pathways. Next, we describe our brain's biology and habituated v. new learning.
Brain biology deeper dive: Our brain’s primary cognition center is known as the cerebral cortex. Our cerebral cortex is physically and logically divided into the right hemisphere (RH) and the left hemisphere (LH). Think of our LH as a logic-seeking serial processor - it handles:
Past information, often from long-term memory;
Current information, often from short-term memory; and
Creates future forecast information, to help us make future judgments.
Our LH also tends to be slow, given the volume of information needing processing and especially the information needed from our long-term memory. Our RH is different. Our RH is connected solely to the present. Think of the RH as a more intuition-based parallel processor, able to input information from our 5 senses as processed via our short-term memory. Our RH relies on readily available habituated information. Our RH tends to be fast. In fact, very fast. From a long-term evolutionary standpoint, our brain evolved to be our protector from danger. For example, our RH evolved from the danger of wild animals or rival tribes of many millennia ago. It is our RH that responds quickly to brake when an animal darts in front of our car. You may thank our brain’s evolution for the fact that we are alive to read this article today! Based on the driving example, a well-trained and experienced (highly habituated) driver may enable fast memory access via the RH. Other than heavy traffic (a situation requiring the LH), the driver may rely upon their RH. [iv]
Much of our day-to-day mental processing is more automatic. Thus, few new synaptic connections are created with habituated activity. A minority of our daily mental activities will include learning something completely new. This newly learned behavior will likely “feel” difficult and challenging. This new activity will create many new synapses, including synaptic development while we sleep. We will discuss why we sleep in the next section.
The Flow State paradox: Reaching flow state is where our brain exists solely in the RH for an extended period of time. The flow state is where both our attention (consciousness) and cognitive resources (information needs or training) are completely in the present. Being in the present is synonymous with full immersion in the RH. Some high-level athletes reach a flow state. They discuss “losing time” as the world around them slows. Even a driver may reach an almost hypnotic state where they seem to lose time in their journey. Some religions call this an enlightened state or “nirvana.” In the Pulitzer Prize-winning book, Goedel, Escher, Bach; the author, Douglas Hofstadter, makes the comment:
“Apparently the master wants to get across the idea that (Zen) enlightened state is one where the borderlines between self and the rest of the universe are dissolved."
One would think we may always wish to reach a flow state. It turns out that reaching a flow state is the outcome of highly disciplined LH-based mental resources training. The flow state is generally temporary, requiring both unique internal and environmental conditions. Most important, building synapses generally requires LH-based training. The flow state is the ultimate outcome of the habituated brain. Thus, even if we could remain in an RH-centered flow state, we would be reducing our ability to develop new synapses. Thus, while the flow state may be “nirvana” it is our slow LH that enables a periodic visit to the flow state and provides for synaptic growth. For a deeper dive into reaching a flow state, please see our article: Soccer Brain - the making of the beautiful game.
All this mental processing sends electrical impulses between neurons and is transmitted via the synaptic connection between neurons. As transmitted via the synapses, much of the electric signals are associated with information signals generated from neurotransmitters. [v] (the neurotransmitters are represented by the yellow dots in the diagram) As generated from our cognition, there is also a small amount of a waste peptide created. This peptide is named Amyloid Beta (“Aβ” is represented by the red dot in the diagram).
Photo Credit: Lisa Genova
This Aβ byproduct occurs for a similar reason that your muscles create lactic acid after a big workout. Lactic acid is what creates that sore feeling after exercising a muscle. Think of Aβ as the necessary byproduct after exercising the brain. In your synapses, you have microglia to sweep away the Aβ byproduct from your thinking process. The challenge is that sometimes your microglia may not be sufficient to sweep away all the Aβ.
In the next section, we discuss how sleep helps the microglia. We also show how brain disease may result from inadequate sleep hygiene. We then will show how sleep is part of our thinking maintenance process, especially concerning memory consolidation and synaptic growth.
3. Sleeping
A very important reason mammals sleep, particularly humans, is to help the brain cleanse the excess Aβ built up in the synapses. The microglia do not always wholly cleanse all the Aβ. When you sleep, specifically in your deep, delta wave sleep, your brain releases spinal fluid to wash away excess Aβ and to help the microglia finish their job of cleaning out the Aβ. Human brains:
Have significant neuron and synaptic capacity and
Are very active in their daily usage of this mental capacity.
As such the need for daily brain maintenance to ensure the brain’s long-term well-being is increased compared to other mammals. Not cleansing the Aβ is the basis for many brain diseases, including Alzheimer’s disease. Excess Aβ may eventually bind together to form Amyloid Plaques (“AP”). AP may eventually overwhelm the synapse and cause synaptic death. [vi] A significant amount of synaptic death will likely cause Alzheimer’s disease symptoms. Thus, sleep is a critical activity to ensure long-term brain health.
Photo Credit: Lisa Genova
In a healthy brain, some synaptic death is normal. No matter how good our sleep hygiene is, most people can expect some synaptic death throughout their lives. It has been shown that active learners are not as symptomatic of brain disease as compared to less active learners. This occurs even though the active learners' brains may present synaptic death. This enables the new synaptic activity to effectively “outrun” synaptic death by rewiring our neural network around the AP-impacted synapses. This means the volume of the new learning will generate enough new synapses to offset the effects of the synaptic death associated with AP. [vii]
Confirming research suggests that sleep hygiene, along with ongoing learning, healthy exercise, and good eating behaviors, is a critical personal mental health activity. [viii] Broad-based neuroscience literature reviews suggest that lifestyle is the critical determinant of long-term brain health. [ix] As an analogy for why good sleep hygiene and other healthy habits are important to prevent brain disease, neuroscientist and author Lisa Genova said:
“Think of amyloid plaques as a lit match, at the tipping point [of brain disease], the match sets fire to the forest. Once the forest is a blaze, it doesn’t do any good to blow out the match.”
Another critical reason we sleep is to process our daily mental activity for the purpose of categorizing and strengthening the synaptic growth associated with daily learning. Generating synaptic connections is an associative activity. Like in the handwriting example, the muscles, balance, language, and visualization of training the offhand to write will generate new synapses. These new synapses will be associated with the existing dominant handwriting-trained neurons. Plus, the new synapses will associate with other related existing neurons. (Like neurons associated with your offhand, with holding a pen, etc.) Thus, many new directly and indirectly associated synaptic connections were made to accommodate the newly learned behavior. Sleep provides the synaptic development environment.
Also, the volume of training for the newly learned behavior matters. As we all experience in our daily lives, the more we practice something, the better we become. This is the process of strengthening synaptic development via repetition. This is a key aspect of the neuroplastic processes to create and strengthen new neural synaptic pathways. As an important nuance, the learning associated with creating new synaptic connections is challenging. It is far easier to do something we know versus something we do not. Just like it is super challenging to learn to write with your offhand. But only traveling down the same mental road repeatedly will not create new synapses. In terms of education, new learning, and synaptic development, the necessary repetition is greatly facilitated via effective study habits. [x] Research (and parent intuition!) shows that student success is associated with the building and application of effective study habits. The next "deeper dive" explores the U.S. challenge of how we think is often misaligned with the current higher education process.
Align higher education with how we think: The extraordinary amount of brain capacity, along with the significant differences in childhood educational opportunity, suggests people are incredibly neurodiverse. Almost all people share a genome with a similar starting point and we mostly share the neuron/synapse brain capacity necessary for college success. But after that consistent starting point, our neurodiversity grows.
Traditionally, U.S. high school graduates are about 17 years old. The U.S. education system generally operates with the assumption that the high school graduate is ready for college. However, given our significant neurodiversity and the diverse environments children are raised, the tradition of universal college readiness of high school graduates is flawed. Effective study habits are often cited as a key success indicator, but not all high school graduates have YET developed these success behaviors. College outcomes are telling. Only a minority of students in the U.S. who start college are able to graduate, get a good job, or not default on a student loan. This article suggests learning is primarily a function of behavioral and environmental influences. Proper assessment of study habits associated with college success is a key behavioral determinant.
“Formal education must change. It needs to be brought into closer alignment with the world as it actually is, into closer harmony with the way human beings actually learn and thrive.”
- Sal Khan, Founder and CEO, Kahn Academy
To dig deeper and consider a new way to align Higher Education with the world as it actually is and how human beings actually learn, please see our article Higher Education Reimagined.
The essence of a healthy brain life is pursuing the mastery process associated with strong synaptic connections, and then pursuing something new and challenging. In other words, work on learning something new until it goes from being a challenge to being automatic - known as "mastery learning." Then it is time for the next challenge. Your good study habits are a key enabler to mastery learning. Plus, all the while, having good sleep hygiene, along with the other healthy behaviors mentioned earlier, supports synaptic development for new learning. [xi]
In the next section, I present my dream perspective. My perspective is a theory on an additional purpose of sleep and how dreams are associated with this sleep purpose. Like any theory, ongoing testing and literature reviews are necessary for validation.
4. Dreaming
Our days are spent performing various mental processing activities as discussed in the earlier “Thinking” section. Some of those processing activities are new and require categorization for long-term memory. It has been shown that we have different memory storage types, from the most short-term to the most long-term. [xii] Think of sleep as the means for converting our more temporary short-term memories into more permanent, recallable long-term memories. The quality of our sleep relates to 1) more efficiently processing daily experiences and 2) creating long-term memories. Importantly, sleep helps us to “connect the dots” between memories, both newer memories from the day and existing memories. The creation of additional synapses is like the connection of another network branch in our brain’s neural network. The strength of the memory and our ability to recall is based on the number of synaptic connections to like memories.
Building memory by building many synaptic connections: If all you have ever learned about Jeff Hulett is that he wrote the article "Dreams are a window to our memories," then you likely will not remember Jeff Hulett. However, if you have also learned that Jeff Hulett is married to Patti Hulett, Jeff has 4 children, Jeff is a behavioral economist, Jeff is a software and services company executive, Jeff leads a nonprofit, and Jeff declares himself a Christian but he left the Catholic Church; then you are much more likely to remember Jeff Hulett. Each of those disparate facts about Jeff, when committed to long-term memory, will create a separate synaptic connection. Additional synaptic connections increase the likelihood and speed of long-term memory recall.
On the flip side, lack of sleep will reduce your ability to commit those short-term memories to your synapse-connected long-term memory. Unconnected short-term memories will get crowded out by newer short-term memories and ultimately be lost.
Cramming for an exam - A counterproductive memory development example: College students are famous for “pulling all-nighters.” This is characterized by an exam scheduled for tomorrow and the student staying up through the night to study. The ability to stay awake is likely enhanced by caffeine or related stimulants. The challenge is that without sleep, the learning associated with the ”all-nighter” will not be effectively consolidated and made available for the synaptic processes associated with the subject studied and long-term learning. The student’s ability to perform well on the exam will be limited, perhaps only to uncategorized, unconnected learning that may still exist in their short-term memory. Think of a stack of 100 randomly ordered pieces of paper. Properly ordered, those pieces of paper may mean something, like a story. However, without order, they are mostly confusing noise.
Most short-term memory will lack context. Without proper synaptic or neuroplastic-related processing, the information will be mostly lost and not committed to one’s synaptic neural network. Also, any existing learning, properly processed earlier in the semester, should be available. Although a tired brain does not typically perform memory recall as well as a rested brain. As such, my advice: Go to every class and study as you go. Study enough for your final ahead of the exam, enabling you to get a good night's sleep the night before the final. If faced with an “all-nighter” or “sleep” tradeoff choice, I would prioritize getting a good night's sleep.
Neuroscientist Stanislas Dehaene said [xiii]: "Sleep and learning are strongly linked. Numerous experiments show that spontaneous variations in the depth of sleep correlate with variations in performance on the next day."
Generally, your day’s experiences are captured in your short-term memory as a jumble of information that lacks the strength of connection to existing long-term memories. This is not to say that some of your day’s experiences were not connected to long-term memories. Very likely some were. But connecting an immediate experience to long-term memory requires a conscious process that is not available for most of your day’s experiences. This is because, given the extraordinary volume of sensory input received in our waking life, there are simply too many discrete experiences to process and commit to long-term memory. Therefore, your short-term memory is holding an inventory of your day’s experiences and waiting for long-term processing. The next graphic describes the dream theory: Sleep [1] is where the lion's share of synaptic processing and related neuroplastic processes occur [2]. In sleep, the experiences found in your short-term memory, many of which were created that day, are available for synapse creation [3] or synapse strengthening to associate with like neurons in long-term memory [4].
Dreams are like a window into that synaptic creation process. Imagine every discrete memory is like a picture or a short video. The collection of short-term memories is kept in an inventory but in no particular order. As a matter of practice, a dream will randomly get seeded with a single piece of information stored in short-term memory. From my experience, dreams often get seeded from a particularly salient experience or fear. Stress is a particularly good "dream seeder." From there, the dream narrative is built by rearranging the remaining information available to short-term memory to align with the seeded narrative.
Even in sleep, our brains have the amazing ability to make sense of the world, even our discrete, jumbled experiences as found in our short-term memory inventory. The brain's instinct to seek causality by story-telling is the same instinct that enables cognitive biases and related reasoning errors. N.N. Taleb is an author, philosopher, and financier. In his book The Black Swan, he observes:
"Our minds are wonderful explanation machines, capable of making sense out of almost anything, capable of mounting explanations for all manner of phenomena."
A cognitive bias and reasoning error analogy: Confirmation bias is a type of cognitive bias. This is where your brain naturally weighs information confirming an existing belief more than information contrary to an existing belief. Dream formation is also consistent with a reasoning error known as an error of omission. An error of omission is where one's reasoning utilizes only a subset of available information. In this kind of reasoning error, the remaining information needed to make an accurate reasoning conclusion is omitted. Whether our brain is in a dream state as part of the thinking maintenance process or is reasoning subject to cognitive biases or reasoning errors, all these brain situations work under the same set of rules as evolved from our genome. Thus, our evolutionary-based need for causal ordering is at play in key aspects of our brain functions.
The reason why our brain naturally reorders short-term memories for dreams is the same evolutionary-based mechanism as the reason why "story-telling" related confirmation bias exists. [xiv]
Also, the comparison of a "bias" or an "error" type to a dream is appropriate because a dream, like a bias or error, is not an accurate representation of reality.
Dreams are an assortment of discrete memories rearranged to tell a story. The discrete memories found in the short-term memory inventory may have occurred that day and some may have happened in the more distant past. Even while asleep, your consciousness is observing this synaptic creation process and seeking to make sense of the jumble of pictures and short videos it perceives as your brain processes the jumbled memory inventory while sleeping. This is why dreams seem authentic and original. Dreams are a unique rendering of reordered memory snippets. Via dreams, your consciousness is viewing a window into the long-term memory creation process by observing and seeking to tell a story with the jumbled inventory of discrete short-term memories. As presented in the cramming for an exam example, think of your consciousness as viewing those 100 random pieces of paper. The dream will reorder the stack of papers in a way that tells a fanciful story.
5. Dream summary and conclusion
Dreams are part of our overall thinking process. Dreams are like a byproduct, that provide our consciousness with a glimpse of the extraordinary synaptic development and strengthening process driving our thinking process. This process converts our short-term memories to long-term memory storage. Dreams rearrange discrete and unconsolidated memories to tell a story. Dreams are subject to the same "story-telling" instinct as confirmation bias.
The strength of long-term memories and speed of conscious recall is a function of the synaptic volume and synaptic strength. Good study habits accelerate your ability to learn. Sleep is a critical part of learning and synaptic growth. A lack of sleep is related to insufficient synaptic development and brain diseases such as Alzheimer's disease. A lack of sleep is generally counterproductive to cognition.
6. Notes
[i] Literature reviews suggest the number of neurons in the human brain is reasonably well known, at approximately 100 Billion. The number of synapses is less well-known. 100 Trillion seems to be a starting number, with some estimates suggesting well into the quadrillion. Part of the challenge of measuring synapses is agreeing upon what a synapse actually is! It does seem clear that the number of synapses is variable and is sensitive to behaviors as discussed in this article.
Hulett, Brain Model, The Curiosity Vine, 2020
[ii] There is increasing evidence in the literature that aging brains may be very plastic. This suggests behavior and habits are critical as we age to encourage neuroplastic-based synaptic development. In the referenced study, it is also suggested the neurotransmitter GABA shows signs of being helpful in increasing memory consolidation. "Our work showed that the aging brain is, contrary to a widely-held notion, more plastic than the young adult brain," says Cisneros-Franco.
Cisneros-Franco, Ouellet, Kamal, de Villers-Sidani, A Brain without Brakes: reduced Inhibition Is Associated with Enhanced but Dysregulated Plasticity in the Aged Rat Auditory Cortex. eneuro, 2018
[iii] Nahum, Lee, Merzenich, Principles of Neuroplasticity-Based Rehabilitation, Progress in Brain Research, Volume 207, 2013, Pages 141-171
[iv] We provide more explanation for brain biology in the following articles:
Hulett, Brain Model, The Curiosity Vine, 2020 Hulett, Soccer Brain - the making of the beautiful game, The Curiosity Vine, 2020
[v] We provide more explanation of neurotransmitters in the following articles:
Hulett, Brain Model, The Curiosity Vine, 2020
Hulett, Origins of our tribal nature, The Curiosity Vine, 2022
Hulett, Soccer Brain - the making of the beautiful game, The Curiosity Vine, 2020
[vi] Genova, What you can do to prevent Alzheimer's, TED Talk, 2017 [vii] Snowdon, Aging and Alzheimer's disease: lessons from the Nun Study, National Library of Medicine, 1997
[viii] Much has been written about sleep hygiene and its connection to stress. Cortisol is the stress hormone. Cortisol is a glucocorticoid hormone that your adrenal glands produce and release. Chronic over-production of cortisol is known to have unhealthy effects, including weight gain and the onset of diabetes. Cortisol is also associated with sleep interruption. Thus, managing sleep in the context of your stress levels is important. Please see the following Cleveland Clinic suggestions for managing stress and attendant cortisol levels:
Editors, Cortisol, The Cleveland Clinic, 2022
Robert Sapolsky is a neuroendocrinology researcher, author, and Stanford University professor. Dr. Sapolsky discusses the importance of managing stress levels that cause cortisol hormone build-up. Cortisol build-up may be destructive, especially to children. Too much cortisol will interrupt thinking maintenance processes and reduce the brain's ability to create synaptic connections.
Sapolsky, Behave: The Biology of Humans at Our Best and Worst, 2017
[ix] Toricelli, Pereira, Abrao, Malerba, Maia, Buck, Viel, Mechanisms of neuroplasticity and brain degeneration: strategies for protection during the aging process, Neural Regeneration Research, 16(1), 58-67, 2021
[x] Gentry, Making College a Success by Assessing and Navigating Candidates' Study Habits, Research in Higher Education Journal, 2012
[xi] In the following article, we present our entropy and time framework. We suggest our overarching human physics-based goal is to "Fight Entropy" and we do so by pushing toward lower entropy throughout our life.
Hulett, Fight Entropy: Living your best life by using the practical physics of time, The Curiosity Vine, 2021
[xii] Camina, Guell, The Neuroanatomical, Neurophysiological and Psychological Basis of Memory: Current Models and Their Origins, Frontiers in Pharmacology, 2017
[xiii] Dehaene, How We Learn: Why Brains Learn Better Than Any Machine . . . for Now, 2018
[xiv] We present our "Big 4" decision-making biases in the following article. We demonstrate how confirmation bias, along with other cognitive biases, lay the foundation for biased decision-making impact. These are the same foundational biases impacting our dreams. We cannot escape our evolution-based cognitive biases, even when we sleep!
Hulett, Great decision-making and how confidence changes the game, The Curiosity Vine, 2022
コメント