PSYCHOLOGY AND NEUROSCIENCE

9 mind-blowing facts about your brain

These nine facts will radically improve your mental health.
By Dustin Neathery — March 19, 2020 — 7 minute read

1: Your Brain Has 100 Billion Cells and a Quadrillion Synapses

Each of the brain’s 100 billion cells makes about 10,000 connections with other neurons, called synapses, which yields about a quadrillion connections. In fact, your brain has enough neurons and neuronal connections that theoretically it could store each and every experience in your life, including all the visual, auditory, tactile, and other sensations associated with those experiences. The number of distinct brain states expressed this way far exceeds the number of atoms in the known universe.

Most of the cells in your brain are in the neocortex and the cerebellum. The cerebellum uses lots of cells to allow high precision in coordinated movement. The neocortex uses lots of cells to allow high precision in coordinated movement. The neocortex uses lots of cells for high precision in sensory discrimination and for planning complex behavior.

Some people equate the brain and how it works and stores information with microprocessors. They say that the 100 billion neurons in the brain are like the transistors in a microprocessor. In truth, even the most advanced microprocessors, which have a few billion transistors, can’t hold a candle to the power of the human brain. Why? Because neurons are more complicated than transistors. Digital transistors tend to be either “on” or “off” and connected to only a few other transistors. Each neuron in the brain, however, is like a computer itself, capable of an almost infinite variety of different states. Neurons also typically output to around 1,000 other neurons using about 10,000 connections.

In addition, while microprocessors work mostly in a series, processing a single instruction at a time, neurons work in parallel, processing billions of things at the same time.

2: Consciousness Does Not Reside in Any Specific Area of the Brain

Many people misunderstand how the brain works because of the popular—but incorrect—notion that certain functions reside solely in particular parts of the brain. One part of the brain is thought to house your ability to taste, another ability to see, another your ability to move your right hand, and so on. Given this perception, it’s easy to see why people tend to think that consciousness resides in a particular area, and because we think of consciousness as the highest brain function, we also tend to put this “consciousness location” at the top of the brain hierarchy. Well, as I explain throughout this book, this just isn’t how the brain works.

The brain doesn’t have any consciousness neuron, and no particular brain area, by itself, serves as the seat of consciousness. Nor is consciousness just a function of brain size; otherwise, elephants would be conscious and humans not. No place in the brain receives the results of all the neural processing in the rest of the brain, so there’s no “top” to the neural hierarchy, and nothing in the brain “looks at” images formed in other parts of the brain.

Instead, several areas of the brain are necessary for consciousness. Areas of the brain that seem to be necessary for and activated by consciousness include the thalamus, the prefrontal cortex, and portions of the parietal and medial temporal lobes. Still, these areas are not unique to the human brain, although the prefrontal cortex is larger (as a percentage of body weight) in humans than any other animal. In addition, damage to the reticular formation in the brain stem produces unconsciousness, but the brain area exists in the non-mammalian vertebrates such as lizards and frogs.

2: It Has No Pain Receptors

Although the experience of pain is dependent on brain areas such as the anterior consulate cortex, the brain tissue itself actually has no receptors for pain. The brain “experiences” the pain resorted be receptors elsewhere in the body, mostly in the skin.

Because brain tissue has no pain receptors, surgery can be done on the brain with the patient fully awake (although tranquilizers and analgesics are typically given to reduce anxiety, and local anesthetics are used for the early phase of the surgery where the scalp skin is cut in order to remove a piece of the skull).

When you have a headache, then, it is not usually because something in your brain hurts, but because a pain message from somewhere in your body reaches the brain. For example, you can get a headache because you actually have mild indigestion or some other body pain of which you are not directly aware.

This doesn’t mean, however, that brain dysfunction can’t be felt as pain. Migraine headaches appear to be due to transient vascular problems in the brain that might lead to abnormally high neural activity, which is felt as pain not because pain receptors are activated, but because some unknown brain circuit interprets that excessive activity as painful. Tumors and strokes may induce excessive brain activity that the brain similarly interprets as painful. In some cases, pain receptors may be activated but referred to the wrong place (as when trigeminal pain receptors are activated).

Another example is the pain associated with looking directly at a very bright light. There are no pain receptors for bright light in the eye, but the brain interprets something about the firing of ganglion cells going from the eye to the brain as indicating that the light level is high enough to be damaging, and it’s felt as pain.

Cutting the Largest Fiber Tract in the Brain Produces Few Side Effects

The largest fiber tract in the nervous system is the corpus callosum, which connects the left and right brain hemispheres. This fiber tract contains about 200 million axons.

This tract has been severed surgically many times to stop epileptic seizures from spreading from one cerebral hemisphere to the other, becoming amplified, spreading back, and producing a whole brain grand mal seizure.

When this procedure was apprehensive tested on a few patients, the results were remarkable.

Amthor, Frank. Neuroscience For Dummies. Wiley, 2016.

1: Your Brain Has 100 Billion Cells and a Quadrillion Synapses

Each of the brain’s 100 billion cells makes about 10,000 connections with other neurons, called synapses, which yields about a quadrillion connections. In fact, your brain has enough neurons and neuronal connections that theoretically it could store each and every experience in your life, including all the visual, auditory, tactile, and other sensations associated with those experiences. The number of distinct brain states expressed this way far exceeds the number of atoms in the known universe.

Most of the cells in your brain are in the neocortex and the cerebellum. The cerebellum uses lots of cells to allow high precision in coordinated movement. The neocortex uses lots of cells to allow high precision in coordinated movement. The neocortex uses lots of cells for high precision in sensory discrimination and for planning complex behavior.

Some people equate the brain and how it works and stores information with microprocessors. They say that the 100 billion neurons in the brain are like the transistors in a microprocessor. In truth, even the most advanced microprocessors, which have a few billion transistors, can’t hold a candle to the power of the human brain. Why? Because neurons are more complicated than transistors. Digital transistors tend to be either “on” or “off” and connected to only a few other transistors. Each neuron in the brain, however, is like a computer itself, capable of an almost infinite variety of different states. Neurons also typically output to around 1,000 other neurons using about 10,000 connections.

In addition, while microprocessors work mostly in a series, processing a single instruction at a time, neurons work in parallel, processing billions of things at the same time.

2: Consciousness Does Not Reside in Any Specific Area of the Brain

Many people misunderstand how the brain works because of the popular—but incorrect—notion that certain functions reside solely in particular parts of the brain. One part of the brain is thought to house your ability to taste, another ability to see, another your ability to move your right hand, and so on. Given this perception, it’s easy to see why people tend to think that consciousness resides in a particular area, and because we think of consciousness as the highest brain function, we also tend to put this “consciousness location” at the top of the brain hierarchy. Well, as I explain throughout this book, this just isn’t how the brain works.
The brain doesn’t have any consciousness neuron, and no particular brain area, by itself, serves as the seat of consciousness. Nor is consciousness just a function of brain size; otherwise, elephants would be conscious and humans not. No place in the brain receives the results of all the neural processing in the rest of the brain, so there’s no “top” to the neural hierarchy, and nothing in the brain “looks at” images formed in other parts of the brain.
Instead, several areas of the brain are necessary for consciousness. Areas of the brain that seem to be necessary for and activated by consciousness include the thalamus, the prefrontal cortex, and portions of the parietal and medial temporal lobes. Still, these areas are not unique to the human brain, although the prefrontal cortex is larger (as a percentage of body weight) in humans than any other animal. In addition, damage to the reticular formation in the brain stem produces unconsciousness, but the brain area exists in the non-mammalian vertebrates such as lizards and frogs.

2: It Has No Pain Receptors

Although the experience of pain is dependent on brain areas such as the anterior consulate cortex, the brain tissue itself actually has no receptors for pain. The brain “experiences” the pain resorted be receptors elsewhere in the body, mostly in the skin.
Because brain tissue has no pain receptors, surgery can be done on the brain with the patient fully awake (although tranquilizers and analgesics are typically given to reduce anxiety, and local anesthetics are used for the early phase of the surgery where the scalp skin is cut in order to remove a piece of the skull).
Amthor, Frank. Neuroscience For Dummies. Wiley, 2016.