Memory
How memory is stored and updated in the brain as well as error/a lapse of memory or even fabrication occurred at that moment, which could lead to false accusations medical malpractice.
To the current understanding, memory is the change in the transmission efficiency of synapse: a joint between neuron and another neuron (nerve cells in the brain cells). The efficiency can be boosted by increasing the amount of protein that accept neurotransmitter released there. One research concluded that if the transmission of the protein was interrupted, academic performance was dropped. The protein activates when memory is generated and evoked. So memory could be changed not only when generated but also when evoked, and therefore, a lapse of memory and fabrication can be occurred when updated.
Sensations
When a person loses a hand or leg or loses all sensation due to nerve damage in the hand or leg, but still feels as if the impaired hand or leg is still there, this is called phantom limb sensation, and the pain in this phantom limb is called phantom limb pain. Phantom limb pain occurs in about 50-80% of people who have lost a hand or leg. It is a condition in which the nerves in the arm have been removed from the spinal cord, e.g. in an accident. Since there is no hand or leg physical exist and the brain is the one that is feeling painful is the brain, painkillers cannot be a help.
Humans receive sound through air vibration and color through electromagnetic waves. Ears and eyes only accept air vibration and electromagnetic waves (real phenomena) respectively, and the brain creates sound and color. Similarly, the sense of touch, as given an example of phantom limb sensation above, works in the same way. For example, if you stubbed your toes and feel painful, the one feeling painful is not the toes themselves but the brain. The brain feeds back information about the location of the pain to the brain. according to law of projection of sensation, any level of stimulation is a phenomenon caused by stimulation of sensory nerve circuits on the cerebral cortex, which project sensations to the point of stimulation. The image below is a "homunculus", that indicates the fact that the surface area of the body does not correspond one-to-one with the corresponding area of the brain.
It's like a map in the brain. That means given the brain electrical stimulation is different from having actual sensation. The Matrix could be coming true!?
So, coming back to the topic of phantom limb pain, the pain is triggered not due to the cut limb itself but due to nerve cells in the brain still activating even after the limb is cut, which makes it feel painful. But why?
If a limb is cut, the brain realm that were initially in charge of the limb will no longer will be used, but instead other realms (eg. shoulder) spread, and occupy and utilize the realm, which is the ability that the brain originally equip, called plasticity. For instance, you will be able to to manipulate prosthetic limbs better by the shoulder realm spreading and functioning better. Then why such a bug happen in phantom limb pain?
It's because of a bug occurred by the higher brain function. When a limb is cut and the realm is replaced by another realm, the higher brain function sometimes does not recognize that the brain map has updated as the neurons start activating again although as another function. This topic also ended up coming back to the topic of synapses.
Changing the example a bit, a surprising fact is that almost half of the entire realm is occupied by vision. However, an interesting thing is that electric signals delivered to the brain through eyes and ears are the same, and whether they will be light or sound is determined depending on their directions (whether they will go to the visual or auditory cortex). For example, those who lost their vision due to an accident often see things with sound instead. Thanks to the brain's plasticity, in which the brain does not tell the difference in what kind of information has been transmitted. Thus, visually disabled people perceive the world, using sound, with superior hearing ability.
You may feel compassionate or superior for disabled people, but there are as many realities as there are people. For instance, dogs use their sense of smell, which is 3000-10000 times superior, to reconstruct the world. Do disabled people themselves feel compassionate for themselves? Not necessarily. Even those of you who do not have physical disability might have experience the same. Tinnitus is also a part of a brain bug. Tinnitus is the most common disability complained of by servicemen who have experienced Iraq War.
Finally, I hope you will enjoy my favorite Japanese blind pianist, Nobuyuki Tsujii (辻井伸行)! See you next time ☆
Reference: Brain Bugs: How the Brain's Flaws Shape Our Lives by Dean Buonomano
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