One of the objectives of this blog is to educate the reader about neuroscientific concepts that may aid the understanding of the personal human experience. I would love for this blog’s visitors to learn and develop insights about their own experiences by becoming familiar with neuroscientific concepts/frameworks. Thus, occasionally some pieces may be neuro-lingo heavy while others will mainly be creative and wordy (I’ll try to trim my Nabokovian tendencies).
The first resource I recommend visiting when you find yourself in doubt while reading this blog is the website: http://www.brainfacts.org (“an authoritative source of information about the brain and nervous system for the public” [created by neuroscientists] – quote taken from the “About Us” section of the page).
The following information is meant to serve as a primer and resource for some of my future posts. Here are the “Neuroscience Core Concepts” outlined in the aforementioned page with additional personal commentary. I suggest visiting the NCC link for a more interactive learning experience. If you are puzzled by any of the terminology or explanations, fret not, you may easily consult the BrainFacts glossary.
NCC #1: The brain is the human body’s most complex organ.
- Unsurprisingly, it is widely recognized as the most complex biological structure on Earth. In fact, there is a consensus among many neuroscientists and other members of the scientific community that regard it as “the most complex structure in the known universe”. Naturally, I am delighted as well as skeptical at this notion, mainly because it is the hypothesis of human brains working with a biased set of “known” information.
- The reasoning behind this core concept is not difficult to understand. Since this is just an intro I’m going to get lazy and let Wikipedia semantics deal with this one: “Complexity describes the behavior of a system or model whose components interact in multiple ways and follow local rules, meaning there is no reasonable higher instruction to define the various possible interactions.” The level of complexity of the possible connections within the nervous system as well as the complexity of the products (i.e. consciousness, emotion) that emerge from these interactions is simply unmatched by any other biological system in the human body. Humans, who intuitively perceive and memorize and learn, have developed an understanding of nature which allows us the capacity to manipulate it and adapt and create in a way unique to our species. Our mental illnesses are also endemic to our nervous system. And yet. Our knowledge of how our nervous systems evolved to enable these faculties and illnesses or how they result from our biology remains inconceivably limited while our ignorance (about what we don’t know and about what we don’t know that we don’t know) seems to expand beyond the far reaches of our imagination.
NCC #2: Neurons communicate in electro-chemical signals.
- The nerve cell, most commonly referred to as the neuron, is the “basic building block of the nervous system”; the neuron has the ability to conduct electrochemical (commonly referred to as nerve) signals through its structure. These are then passed on to other neurons through what are known as synapses (essentially interfaces for communication between neurons). Nerve signals are how information is encoded and conveyed throughout the brain.
- Here’s an oversimplified account of the most common relay of a nerve signal through a neuron unto the next (refer to diagram for the illustration of the parts of a neuron): pre-synaptic neuron’s dendrites -> cell body -> axon hillock -> axon -> axonal terminals of pre-synaptic neuron -> synapse -> post-synaptic neuron’s dendrites.
- Synapses are small gaps between the effector part of one neuron (“mouth”) and the receptor part of another (“ear”). These allow, through electrochemical means, the conveyance of a nerve signal from one neuron to the next, which is how neurons communicate information about external stimuli, internal states, memories, etc.
- The main method of communication through synapses (exempting gap junctions) uses the release and reception of molecules called neurotransmitters (you may think of these as the messages one neuron sends to the other). There are a variety of neurotransmitters, each adding complexity to the neuronal language.
NCC #3: Neural circuits are the foundation of the nervous system; the organization of these is genetically pre-determined.
- “Neurons never function in isolation”. For the purposes of this NCC we’ll stick to defining neural circuits as such: a neural circuit is an organized ensemble of nerve cells which processes a specific type of information (e.g. visual, spatial, painful). You could think of them as pathways for different types of information.
- Neural circuits’ mechanisms of transmission and organization vary according to their genetically pre-determined function, but their components are generally the same: neurons and glial cell processes which facilitate and accelerate the conduction of nerve signals as well as strengthen or weaken connections between neurons.
- This neuronal circuitry is originally “determined by genetic programs during embryonic development and modified through interactions with the internal and external environment”. In other words, neural circuits are initially the result of the genetic blueprint of your brain. And, as we’ll discuss in the next NCC, they are subject to change.
NCC #4: Life experiences change the nervous system.
- This NCC indirectly refers to an emerging field of study which has revolutionized biology (and will continue to do so): epigenetics (i.e. “chemical modification of specific genes or gene-associated proteins of an organism”). Moreover, it directly refers to a most beloved neurological phenomenon: neuroplasticity. As the term suggests, neuroplasticity refers to the nervous system’s adaptability or capacity to modify itself structurally and functionally in response to experience/stimuli. Throughout a human’s lifetime, the brain is constantly reorganizing, modifying, and creating or pruning neural connections in response to experiences. Consider this: currently, your brain is already slightly different from your brain at the beginning of this day, even from your brain at the beginning of your reading this post!
- “Differences in genes and environments make the brain of each animal unique.” In the case for humans, the complexity of our brain, our social interactions, and our environment allows for an inconceivable number of possibilities for the brain to keep changing itself.
NCC #5: Intelligence arises as the brain reasons, plans, and solves problems.
- Frankly, do we know what intelligence is? Even though I have sifted through a considerable amount of definitions and theories regarding intelligence, I still can’t offer a clear explanation of what it is. I am kind of partial to the idea that there are multiple intelligences because it makes some sense to me that natural selection would result in such a variety. Plus, my personal experience also supports this idea.
- Nevertheless, my understanding is that this NCC refers to human intelligence as cognitive capacity cultivated throughout the development of the nervous system (can a newborn baby be considered intelligent?). I am also of the opinion that some non-human animals are possessed of intelligence.
NCC #6: The brain makes it possible to communicate knowledge through language.
- Imagine a world where language does not exist. Would this world house organisms with nervous systems identical to ours? This NCC seems to suggest not. We still have a ways to go to understand how language emerged in humans and is processed by the nervous system, but its function and value are indisputable.
- As social and creative creatures, the development of language as a means of communication has been essential to our cultural evolution, to science and art, to any type of production, to civilization; essentially to our success as a species.
- I personally would never want to live in a reality without language. Thanks, human brain?
NCC #7: Human brain endows us with natural curiosity to understand how the world works.
- The human brain is a curious brain. It also manifests a natural craving for novelty (just as the bee brain does apparently). Once our early ancestors wandered and explored around, questioning and observing the strange environment in which they would have to learn to survive, this curiosity must have served them immeasurably (making it a prime trait for selection).
- Humans want to learn, want to understand, and want to amass knowledge so that they can manipulate the world around them to their favor. William James described it as “the impulse towards better cognition” (cognition being the mental process through which we acquire knowledge and understanding from experience). Curiosity feeds the will to learn.
NCC # 8: Fundamental discoveries in the study of the nervous system promote healthy living and treatment of disease.
- Can’t say much about this one. Everybody knows that this is one of the main reasons why most of neuroscience (or any research associated with biology) gets funded. As imperative as research is for making fundamental discoveries in service of the advancement and enhancement of mankind, contributing knowledge to promote healthy living and improve treatment of disease gets priority. This perhaps may be considered one of the scientist’s social or civic responsibilities.