Whatever! Were we Thinking?
Surprisingly the model for how the brain learns that we have used for the past hundred years has almost no supporting science behind it. We knew more about the far side of the Moon than we did about how our brain learns
- up until now!
Some fast facts; just in case you thought you knew how the brain learns! We knew our current model for how the brain worked was flawed when we discovered that:
1. Humans have the lowest ration of neurons (7%) of any species and the highest ratio of astrocytes (76%). Einstein currently holds the record for the lowest ratios of neurons and the highest ration of astrocytes of any human tested. If you are reading and think you may well beat Einstein - Well, you sort of have to be dead for someone to do the cell count so that could be a high cost of proving your point.
"Three published scientific studies examined the brain. 'On the brain of a scientist: Albert Einstein' appeared in 1985 and analysed the ratio of neurons to glial [predominantly astrocytes] cells, specific cells that provide nourishment. In one area of the left side of Einstein's brain there were 73% more glial cells per neuron than average . . ." Carolyn Abraham
2. Clever people map and automate cognitive patterns, we call concepts and to do that we download additional stem cells from the gyrus in our brain. Most of these stem cells become astrocytes. Astrocytes work with neurons to map and automate concepts (patterns) into non-conscious processes such as driving and eating and almost 90% of what we do in any given day. The more new concepts you map the more astrocytes you get. Those additional astrocytes are then on the prowl for patterns/concepts that need to be mapped. All these additional astrocytes looking for concepts increase the potential of your neural sequences being interrupted, resulting in you having 'senior moments.' These are those embarrassing moments when you cannot remember simple things like where are my glasses or "Oh heck! What is her name again?" The smarter you are, due to all those new concepts, the more senior moments you will have. Less smart people don't have as many senior moments so next time you have one just revel in the joy of being too smart!.
. . the older you are the brighter you are and the more you will forget because in general you don’t need to remember those things:
“older - smarter - more efficient - slightly forgetful!” Seems like a good deal to me! And no, that's not due to Alzheimer’s!
3. 100’s of people (up to the age of 23-ish), have had a complete hemisphere of their brain removed (cortex only) with surprisingly little damage. Note: this is not a quick piece of cosmetic surgery in order to reduce weight. Actually the cerebrospinal fluid that replaces that half is more dense that your brain so you actually gain weight - AND no the half left (or right) does not flop around as the pressure of the cerebrospinal fluid keeps it nice and steady. Those that have this operation generally have severe epilepsy or fitting that has a high chance of killing them if they do not have the operation.
4. If you are blind it is possible to “see” using your tongue instead of the non-functioning eyes! Seriously, but you have to have a have a small plastic paddle attached to the back of your tongue with the wires attached to micro cameras in a set of glasses - the glasses do not help these blind people see - they just host the cameras! What this does support is the idea suggested in 1987 by scientist Vernon Mountcastle that all our senses can be replicated using other sense organs.
"It's a concept in which you replace a sense that was lost by another one that is there," said Maurice Ptito, the neuropsychologist supervising the study. "They sense the world through their tongue, and that gives them the feeling of seeing. You don't see with your eyes. You see with your brain."
5. Savants can remember and recall extraordinary long sequences of numbers, words or even music. Daniel Tammet holds the world record for remembering mathematical Pi to 22,514 decimal places; very cool, but not the useful thing to remember for most people. Interestingly Daniel struggles with formulating and applying even the most simple of concepts in daily life. Savants can sequence exceptionally well, whether that be numbers, words, music, art or even drawing what we have seen on a grand scale (see Stephen Wiltshire - www.youtube.com/watch?v=a8YXZTlwTAU)
6. You cannot see pictures in your head. Seriously; if we could do this we would not need photos and we would all have a photographic memory, which by the way does not exist for anyone! Seriously!
"One common fallacy is to assume there is an image inside your eyeball, the optical image, exciting photoreceptors on your retina and then that image is transmitted faithfully along a cable called the optic nerve and displayed on a screen called the visual cortex. Now this is obviously a logical fallacy because if you have a screen and an image displayed on a screen in the brain, then you need another little chap in there watching that image, and there is no little chap in your head.” VJ Ramachandran
7. You have 23 senses that merge together to give you a sense of your world, seeing, hearing, balance etc do not happen in a specific place in your brain; although there are busy neural networks for each of your senses. Your senses merge into a single stream to give you a sense of someone, a place or an idea.
8. Each of your 100 billion neurons has between 10-100 thousand dendrites and each dendrite has between 10-100 thousand dendritic spines that can form synapses but in practice each cortical neuron develops approximately 10 000 synapses. Then of course we have to add to that the role of the astrocytes and they are ten times as numerous as neurons. BUT astrocytes are not electrically managing information but rather they do this chemically; sure that is slower but astrocytes can get the neurons to do the their work for them - especially when it comes to higher order thinking.
9. ’On the back of an envelope’ calculation: 100 billion neurons multiplied by 10 000 synapses/neuron and we have 1015 synapses that weigh about 100grams or 1013 synapses/gram. Contrast this to a modern chip that has 109 transistors/gram This means that your brain is about 10 000 times more powerful than a computer chip and is not limited to outputting just 1’s and 0’s but rather thousands of possible outputs-inputs.
“In a recent lecture at Harvard University neuroscientist Jeff Lichtman, who is attempting to map the human brain, has calculated that several billion petabytes of data storage would be needed to index the entire human brain. The Internet is currently estimated to be 5 million terabytes (TB) of which Google has indexed roughly 200 TB or just .004% of its total size.”
10. Your brain makes computer chips look pathetic but add to that the fact that neurons can output not just trivial 1’s or 0’s like a transistor but a range of billions of unique outputs-inputs. Add to that, each synapse can act as a memory gate, equivalent to an electronic memristor. Electronic components called memristors are hundreds of times more efficient that transistors as they can store a memory of the resistance it experienced in the past and this is the basis for how we are now think synapses work.