Sunday, August 12, 2012

#16 Your Brain

There is way too much information on the brain for me to cover in a short blog post, but I want to give some convincing highlights (probably more that you want to read). Here is a quote that will get us started.

"Scientists claim that the most complicated and mysterious thing in the universe is the human brain. Scientists know more about stars exploding billions of light years away than they know about the brain." [1]

The brain is a vast mystery and our greatest scientists have not figured it out. That makes a great case for me that it must have been created by a higher intelligence than ours. To think that it happened accidentally when our greatest minds are very far from understanding it's complexity is preposterous. Accidents do not create order.


The human brain consists of approximately 100 billion neurons. That, by the way, is about how many stars there are in our Milky Way Galaxy. [3]

Each neuron has somewhere between 1,000 and 10,000 synapses, equaling about 1 quadrillion synapses. [2]

Another source quotes up to 40,000 synapses per neuron. [3]

There are possibly as many connections in your brain as there are stars in the known universe.

If all the neurons in the human brain were lined up, they would stretch 600 miles. [2]

A piece of brain tissue the size of a grain of sand contains 100,000 neurons and 1 billion synapses, all "talking" to one another. [3]


Human brain's are comparable in computing power to the world's greatest computers, but fantastically better at almost every other task while fitting inside your skull and using only the power of a small lightbulb.

"The world’s most powerful supercomputer, the K from Fujitsu, computes four times faster and holds 10 times as much data. And of course, many more bits are coursing through the Internet at any moment. Yet the Internet’s servers worldwide would fill a small city, and the K sucks up enough electricity to power 10,000 homes. The incredibly efficient brain consumes less electricity than a dim lightbulb and fits nicely inside our head." [4]

A human brain is 75% water and has the consistency of tofu, custard, or gelatin.[5] You could cut it with a table knife [6].

Note also that the human brain accomplishes everything at a relatively slow speed, nothing like a computer. Impulses travel at only about 223.56 miles per hour.

"Axons, the long output connection from a cell, come in two types: myelinated and unmyelinated. Myelinated axons have an extra layer of "insulation," a fatty substance, which allows the impulse to travel about 10 to 100 meters per second. Unmyelinated axons only transmit at about 1 meter per second. When the signal reaches the end, it has to cross the synapse to influence the next cell, which adds about 5 ms. (10 meters per second = 22.356 mph and 100 meters per second = 223.561 mph.) As you can see it is a lot slower than the speed of light in a vacuum which is exactly 299,792,458 metres per second, or 186,000 miles per second, or 670,616,629 mph." [6]

A 20-year-old man has around 109,000 miles of myelinated axons in his brain, which is enough to wrap around the earth’s equator four-and-a-half times. [7]

Here is an amazing fact. 3 year old babies have twice as many connections in their brains as adults.

"Babies are born with around a 100 billion brain cells, but only a small number of neurons are actually connected. By three years of age a child's brain has formed about 1,000 trillion connections, about twice as many as adults have. At around 11 years, the brain begins to prune unused connections. Connections that are used repeatedly in the early years become permanent; those that are not are eliminated." [6]

There are more than 100,000 chemical reactions happening in the human brain every second.[7]

The human brain has around 100,000 miles of blood vessels.[7] 750-1000ml of blood flows through your brain every minute. That's enough to fill about 3 full soda cans. [12]

"Research indicates that men and women have different structures and wiring in the brain. For example, the frontal lobe—which is responsible for problem solving and decision making, and the limbic cortex—which is responsible for regulating emotion, are larger in women. Women also have about 10 times more white matter than men." [8,9]

Here is a quote from Jeff Hawkins about computers and brains in his 2004 book "On Intelligence."

"A human can perform significant tasks in much less time than a second. For example, I could show you a photograph and ask you to determine if there is cat in the image. Your job would be to push a button if there is a cat, but not if you see a bear or a warthog or a turnip. This task is difficult or impossible for a computer to perform today, yet a human can do it reliably in half a second or less. But neurons are slow, so in that half a second, the information entering your brain can only traverse a chain one hundred neurons long. That is, the brain 'computes' solutions to problems like this in one hundred steps or fewer, regardless of how many total neurons might be involved. From the time light enters your eye to the time you press the button, a chain no longer than one hundred neurons could be involved. A digital computer attempting to solve the same problem would take billions of steps. One hundred computer instructions are barely enough to move a single character on the computer's display, let alone do something interesting." [10]

Even if humans compete against single minded computers on a particular task, we have to remember the human brain is doing thousands if not millions of other things at the same time.

"However the computational power of the human brain is difficult to ascertain, as the human brain is not easily paralleled to the binary number processing of computers. For while the human brain is calculating a math problem, it is subconsciously processing data from millions of nerve cells that handle the visual input of the paper and surrounding area, the aural input from both ears, and the sensory input of millions of cells throughout the body. The brain is also regulating the heartbeat, monitoring oxygen levels, hunger and thirst requirements, breathing patterns and hundreds of other essential factors throughout the body. It is simultaneously comparing data from the eyes and the sensory cells in the arms and hands to keep track of the position of the pen and paper as the calculation is being performed." [6]

The more we discover about the brain, the more wondrous and awesome it is.

"The discovery of ventral and dorsal visual streams has only made our work more difficult because it is unclear how these streams fit into the functional architecture of the brain and which parts of the brain receive the resulting signals. Similar problems exist with memory processing. So far, no research team has been able to pinpoint where in the brain memory is and how it functions." [11]

Here is a little bit of information on how synapses work in the brain. This should leave you awestruck.

"Neural synapses in the human brain are extraordinarily complex structures. Responsible for relaying information between neurons, chemical synapses govern the release of over 100 different kinds of neurotransmitters, while electrical synapses deliver information via electricity for rapid-fire reflexes." [13]

"When a nerve impulse gets to the end of an axon, its message must cross the synapse if it is to continue. Messages do not “jump” across synapses. Instead, they are carried across by chemical messengers called neurotransmitters. These chemicals are packaged in tiny sacs, or vesicles, at the tip of the axon. When a nerve impulse arrives at the tip, it causes the sacs to release their contents into the synapse. The neurotransmitters diffuse across the synapse and bind to receptors in the membrane of the cell on the other side, passing the signal to that cell by causing special ion channels in the postsynaptic membrane to open. Because these channels open when stimulated by a chemical (in this case, a neurotransmitter) they are said to be chemically gated.


Why go to all this trouble? Why not just wire the neurons directly together? For the same reason that the wires of your house are not all connected but instead are separated by a host of switches. When you turn on one light switch, you don’t want every light in the house to go on, the toaster to start heating, and the television to come on! If every neuron in your body were connected to every other neuron, it would be impossible to move your hand without moving every other part of your body at the same time. Synapses are the control switches of the nervous system.

When a nerve impulse reaches the end of an axon, it releases a neurotransmitter into the synaptic space. The neurotransmitter molecules diffuse across the synapse and bind to receptors on the postsynaptic cell, a neuron in this case, passing the signal to that cell. Enzymes destroy the neurotransmitter molecules to prevent continuous stimulation of the postsynaptic cell." [14]

As you can imagine, I'm just getting started. Hundreds of books have been published on the brain and thousands more will be. I have even read where some people now believe that your memories are stored in all the cells of your body, not just inside your skull.

Our existence is a total and absolute miracle. Only a supernatural cause could possibly be an explanation for our existence. No materialistic cause, and certainly not a materialistic random accident, makes any rational sense what-so-ever.

There must be a God.

++++++++++++++++++++++++++
References

[1] Newquist, H.P. 2004. The Great Brain Book. New York, NY: Scholastic Inc.

[2] Chudler, Eric. “Brain Facts and Figures.” November 1, 2011.

[3] http://smartnow.com/page/10570

[4] http://www.scientificamerican.com/article.cfm?id=computers-vs-brains

[5] Juan, Stephen. 2011. The Odd Brain: Mysteries of Our Weird and Wonderful Brain Explained. Riverside, NJ: Andrews McMeel

Publishing.

[6] http://www.disabled-world.com/artman/publish/brain-facts.shtml

[7] Turkington, Carol. 1996. The Brain Encyclopedia. New York, NY: Checkmark Books.

[8] Cohen, Elizabeth. “Loving with All Your . . . Brain.” CNN. February 5, 2007. Accessed: November 17, 2011.

[9] Edmonds, Molly. “Do Men and Women Have Different Brains?” Discovery. 2011. Accessed: November 17, 2011.

[10] Hawkins, Jeff. "On Intelligence" 2004

[11] http://www.lucidpages.com/branco.html

[12] http://science.nationalgeographic.com/science/health-and-human-body/human-body/brain-article/

[13] http://www.nextnature.net/2012/06/replacing-synapses-with-a-single-switch/

[14] http://www.txtwriter.com/backgrounders/Drugaddiction/drugs1.html

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