Norman Doidge’s years of discoveries, expertise and intellect mixed up together in this fabulous book, carrier of scientific data of incalculable value all related to our plastic brain.
SUMMARY:
A Woman Perpetually Falling
This chapter initiates us with a wobbler womman who feels like she is going to fall, so consequently she ends up doing so. This womman called Cheryl got help from Paul Bach-y-Rita (a famous neuroscientist) who found the root of the problem, which was on her damaged vestibular apparatus (sensory system that coordinates movement with balance). Thereafter, he created a hat-like machine which would serve as a new vestibular apparatus for Cheryl, capable of sending the right signals to her brain, so that when the hat was put on Cheryl wouldn’t have these falling perception. As time had gone by, Cheryl was beginning to notice remarkable improvements when she took the hat off, she was gaining residual time progressively, meaning that she was able to let that falling feeling fade for a certain amount of time even when the hat was off, until she was able to feel like a normal person with practice, not having to rely on the hat for at least every 6 months. That is the first case we encounter that proves the plasticity of the brain and its ability to change over time adapting itself and rewiring its neuronal connections, we could say that with the purpose of restoring a healthy vestibular apparatus in this occasion.
#Excessive use of gentacimin can lead to hearing loss, ringing in the ears and devastation of the balance system.
Building Herself a Better Brain
Here Barbara, a woman “labeled” retarded discovers how to heal herself. Barbara had trouble with spatial reasoning, understanding relationships between things, logic and she also had a kinesthetic problem (awareness of the position and movement of the parts of the body by means of sensory organs in the muscles and joints) and couldn’t read clocks. She was frustrated also for not being capable of attaching meaning to symbols, due to this all she was working 20 hours a day in her young age in the library, but nothing beneficial came out of it. Until one day, when she read a book from a Russian neuropsychologist named Aleksandr Luria, who tracked the whole process of a soldier’s rehab who had been shot in the brain damaging the left occipital-temporal-parietal region of the brain, and Barbara saw that the effects described by the soldier Zazetsky were the same as hers. Thinking it through she hypothesized that she could have a brain malformation or damage in a certain area from birth. And as Zazetsky did some specific rehab exercises for that brain region in order to improve, so did Barbara.
What Barbara found through massive practice was that she actually was improving so rapidly that she couldn’t believe it. She was now able to read clocks and establish relationships between things and apply logic. Telling us once again that the brain can change through exercise and practice, the more you repeat the specific exercise the better reinforced the neuronal connections will be once the neuronal map is established (although able to change through synapses whenever alterations occur).
#Acetylcholine and dopamine are essential in learning and in the strenghtening of neural pathways.
#Education increases the number of branches among neurons, which drives the neurons farther apart, increasing the volume and thickness of the brain.
Redesigning The Brain
This chapter is full of takeaways and important things to know, so I’ll just make a list: –Michael Merzenich is often praised by lots of neuroplasticians, he is actually the one who created the cochlear implant, the device that allows congenitally deaf children to hear, it does so by replacing the cochlea for the implant turning speech into bursts of electrical impulses which are decoded by our brain and processed like sound in normal people, and our brain is so incredible and plastic that it goes from needing thousands of hair cells to readapt itself and be able to decode from a simple device, that is one of the reasons our brain is so powerful. He has also developed a variety of well-known plasticity-based computer programmes, FastForword for instance has already helped hundreds of thousands of learning-disabled children to improve their cognition and perception. Most of his discoveries were made through the Micromapping Technique, which was based on the usage of microelectrodes inserted on nerve cells, detecting and catching the electrical signal and sending it to an amplifier, which then conveys it to an oscilloscope screen (Oscilloscopes display the change of an electrical signal over time, with voltage and time as the Y- and X-axes, respectively, on a calibrated scale). This technique is still about a thousand times more precise than all brain scans but it is not commonly used because it requires an extremely tedious kind of surgery.
–Wilder Penfield was the one who discovered that motor and sensory brain maps are topographical, meaning that adjacent parts of the body are also adjacent in brain maps, so that the brain maps altogether follow a body-like structure, meaning that maps are not large but small so neuronal connections within a map are closer together.
Each neurons has three parts: The dendrites that receive input from other neurons, the cell body which contains the cell’s DNA and finally the axon which carries electrical impulses toward the dendrites of other neurons, not exactly touching the dendrites because of the space in between called the synapse, used to release the neurochemichals in, called neurotransmitters that bind to the neighbour cell’s dendrites. Having said that the neurons can receive either inhibitory (less likely to fire off) and excitatory (fires off) signals, which depend on the neurotransmitter, the quantity of it and other factors. We previously talked about the rewiral of our brain, neurons rewiring makes reference to the alterations that occur at the synapses, strenghtening or weakening connections. A fun fact about our nervous system is that if we cut off, let’s say a peripheral nerve (a nerve of the peripheral nervous system or PNS) and then the axon of the peripheral nerve reattaches to the axon of the wrong nerve, we feel “false localization”, for example represented by the touch of our index finger, which can be felt on our thumb finger instead of the index. Funny isn’t it?
Here the first cornerstone of neuroplasticity is mentioned, and that is the principle of “use it or lose it”, stating that if an action is not performed for a long period of time the neuronal connections involved in the action will weaken progressively as time goes by, so that the action could be lost. It is also mentioned the reason why our bad habits are so difficult to break, the reason being resides in our neuronal connections for the bad habit, the more repetition of the habit leads to the strenghtening of that neural connections, which are being reinforced so that it would take longer and longer to break or weaken that connections, resulting in the difficulty of breaking a bad habit, and the same principle applies to good habits. That’s why early childhood education is so important to prevent bad habits from taking advantage, and it is also the reason why unlearning is more difficult than learning. Another cornerstone of neuroplasticity is presented in this chapter, the famous phrase “neurons that fire together wire together” stating what we learned before, emphasizing that with repetition strenghtening takes place. “Neurons that fire apart wire apart” and “neurons out of sync fail to link” (If they don’t fire together there’s no link between those neurons). It is of primordial importance to highlight that when a skill is practiced and repeated for a long period of time so as to be at the level of mastery of that skill the brain makes a selection process in which it ceases to use some neural connections used before to perform that skill. It does when neurons become at a great level of efficiency and in order to create more space for different neural connections to take place. Also, when neurons are trained they became more efficient, thus firing more rapidly and increasing our thought speed processing. Some growth factors exist and there was one in concrete that caught Merzenich’s attention, BDNF, which is released from neurons when an activity is performed, it consolidates connections and promotes the growth of myelin (the insulating sheath of neurons that speeds up electrical signaling) and keeps the nucleus basalis from turning off during the critical period allowing for the differentiation of brain maps to take action effortlessly. BDNF is also a plasticity machine itself and when whe have the brain differentiated our body wants stability, hence the closure of the nucleus basalis through the right amount of BDNF release.
##It is thought that the reason for autism is that autistic children have genes that predispose them to autism, and what these genes actually do is help BDNF release to be produced in abnormal quantities resulting in a prematurely closing of the nucleus basalis, leaving the person with undifferentiated regions of the brain. Epileptic people are believed to be affected early in the critical period by white noise (the sound produced by machines, very excitatory for the auditory cortex) which makes some neuronal connections to a massive release of BDNF turning off the critical period prematurely with the big help of the predisposed genes. That’s why human epileptics find that strobe lights at rock concerts set off their seizures.
#A monkey’s hand, like humans has three main nerves: radial, median and ulnar. #Syndactyly is a condition wherein two fingers are fused. #When learning dopamine reinforces the reward while acetylcholine sharpens our memories. #Autism is largely an inherited condition, if one identical twin is autistic there is a 80-90% chance that the other will be as well. #When we are in the critical period our nucleus basalis (part of the brain that is believed to have an important role to sustain the attention by releasing acetylcholine helping our brain to tune in and sharpen memories) is turned on all the time making our brain maps so malleable just by the mere exposure to the world, but when the critical period ends the nucleus basalis only turns on when we exert focus over a thing we want to learn, that’s why if we stay focused we get much more benefit from an activity (i.e. sports drills).
Acquiring Tastes and Loves (Sexual attraction and Love thorugh neuroplasticity)
It is believed that sexuality is itself an instinct, and if we look at the definition of instinct it is defined as a hereditary behaviour unique to a specie which varies little from one member to the next and generally resists change and it has a hardwired purpose, survival. But the human sexual instinct has been somewhat detached from its core purpose, reproduction, differing from the other animals; we have got to this point because of our plastic brain. And there are certain areas that made this transformation possible, the most crucial one’s being the hypothalamus (regulates instinctive behaviours including sex), the amygdala (playing its role in emotion and anxiety) and the hippocampus (short-term memories to long-term process). A thing I did learn through online research was that when we stress there are hormones called glucocortides that are being released in our body, killing the cells in our hippocampus, thus making us less able to transform memories to long-term. So don’t stress out, keep calm and enjoy every moment of your life. The sexual instinct is being shaped from the moment we are born via environmental factors such as our parents influencing us with what we would later be an acquired taste developed by us based on our experiences. If a parent is warm and gentle the child would probably seek out for this qualities later on when choosing an adult mate.
A curious fact related with sexual plasticity is that when adults make use of baby words like “sweetie pie” for instance, to give to the conversation an oral flavor they are actually unmasking old neural pathways partially buried from childhood, so that the person gets a feeling of regression to some old memories which can be either harmful or harmless whether they had good experiences or bad one’s as children (quick note here, it could be use on your favor, so think about it) From here we can conclude that the odds that forms of fetichism, masochism… can be developed during infancy are very high. And the only way of getting out of these forms is by unlearning the associations of neurons once arranged to develop that acquired taste, but this is not an easy task.
Speaking of dissociations we should remark that in live there occur two massive brain reorganizations at two different stages: When we fall in love (oxytocin the neuromodulator is released when making love) and when we begin parenting (vasopressin the neuromodulator is released). All this neuromodulators in presence to change the structure of neurons and connections to allow the individual to perform the task at its best.
##Addictions, either drug and nondrug cause long-lasting effects: When a drug is taken it produces a protein in the body called ΔFosB, as more drug dosis are taken more ΔFosB accumulates in the neurons until we get to the point that this protein turns on and off certain genes, leading to effects lasting even after the drug is stopped, also leaving us with a damaged dopamine system. Cocaine reduces the threshold of our pleasure centers to fire, so that they fire the electrical signals more easily, that’s the reason why we feel pleasure from whatever we do when cocaine induced. #We have two pleasure systems: the excitatory (dopamine-related) and the satisfaction system (endorphines release, related with opiates). #Dopamine likes novelty, imagine a marriage case, both individuals are mutually attracted by each other but their pleasure systems adapt and it is harder to get the same buzz they once got from each other. #From a neuronal perspective, the neuronal process by which we learn is called LTP (long-term potentiation) and the process by which dissociations are caused by unlearning are called LTD (Long-term depression). #Neuromodulators enhance or diminish the overall effectiveness of synaptic connections and bring about enduring change. #Cystic fibrosis, genetic disorder of the lungs and pancreas in which it is produced an abnormal quantity of mucus that clogs the air passages difficulting breathing and leading to digestive poblems.
Midnight Resurrections
Here we are presented with Edward Taub, a behavioral neuroscientist from which extremely useful experiments and experience can we take benefit. Taub’s essential contribution through his patient’s cases has left us with tons of valuable information, taking as an example his training principles which sport athletes apply to their everyday life: the discovery that training is more efficient if done in increments, and work should be concentrated into a short-time, also referred to as “massive practice”(the reason why it is always better to immerse yourself into a foreign country if you want to learn a new language).
Brain Lock Unlocked
This chapter is exclusively dedicated to patients with OCD (obsessive-compulsive disorder). Mainly focusing on their inability to make a worry fade away, keeping on checking things though previously checked lots of times, a switch of task they cannot perform because they are trapped in a sort of loop due to a “glitch” in their brains that can be redirected for the good with the help of neuroplasticity. I’ll explain this with a common example: A patient with OCD leaves home and starts hesitating whether he had locked the door or not before leaving, this patient is going to start worrying more than normal people because of his OCD and is going to check out if the door was locked or not and afterwards he’s going to check again thinking about which way did he/she rotated the key, was it left or right? Did I just checked in vain?
The reason being can be demonstrated looking at brain scans of OCD patients, this brains presenting three main structures with malfunctioning:
–The orbitofrontal cortex which detects the mistake and doubt is generated (sends a signal to the cyngulate gyrus).
– The cyngulate gyrus which triggers anxiety.
–And the caudate nucleus which allows our thoughts to flow from one to the next, is sticky in OCD patients. The three areas are hyperactive in OCD patients and the orbitofrontal cortex and cyngulate gyrus are turned on all the time leading to an increased anxiety even after the mistake is corrected because of the inability of the caudate nucleus to “turn the page”. The soultion found for OCD patients was to shift the caudate nucleus “manually” with focus and resistance to the stimuli,by implementing your focus to another activity, henceforth weakening the old pathway and promoting the formation of a new one.
Pain
Here’s one of my favourite chapters of this book. Pain is a feeling that all of us have experienced at some point in life, but what Doidge encompasses here introducing us to Ramachandran is the Why we feel pain, which systems are involved and dives right into the possibility of blocking pain so that we don’t experience it, which it is in essence what yoggis in India do to be able to walk barefoot in hot coals or nails.
My takeaways here are the following ones:
-Pain is felt because in some way we want to feel it.
-The brain creates a body image from which we feel pain, our body image consists of our muscles, joints, bones, limbs… Through a Ramachandran experiment we now know that our body image can be merged with a piece of furniture!
The experiment recquired a person to place his right hand under a table, Ramachandran would tap the tabletop at the same time he exerted the same amount of tapping pressure to the patient’s hand. As repetition went on the map finally merged the hand with the table, and when Ramachandran pulled out a hammer that was previously hidden showing his harming intentionality to the table, the patient was so frightened that his stress felt like actual pain.
-There’s a pain theory called “the gate theory” which states that we’ve got gates connecting to our pain system and that if we manage to block this gates we won’t feel pain anymore until they are unblocked. There was proof of the possibility of blocking the gates when TENS (transcutaneous electrical nerve stimulation) came in, which can be used to stimulate pain inhibitory neurons that block the gates. It also seemed possible that acupuncture could also inhibit neurons closing the pain gates.
Imagination
Imagination discoveries have been groundbreaking in the world of science among many others; it has been concluded (Pascual Leone being a pioneer) that imagining an act an doing it are not as different as they sound, i.e: when visualizing (imagining) the letter “c” our visual cortex lights up, just as it would be when physically seeing letter “c”. Imagining engages the same motor and sensory programs that physical action does, and I’m going to make it easier with a study done with the help of a large group.
This large group was splitted into two different groups, group A and group B. Both groups were asked to perform the same body weight exercises covering all the muscle groups for a month. But they differed in the way they had to do it. Group A had to imagine themselves doing this exercises on a daily basis until the month got at its end, while group B had to actually do the exercises physically. The surprising results after the experiment were astonishing, group A had increased their muscular mass by a 22% while group B increased it by 30%, only 8% of difference between both groups! This experiments made it possible for top athletes to perform better by using the power of imagination and visualization.
#Our brains are not truly organized in terms of systems that process a given sensory modality. Rather they are organized in a series of specific operators, meaning that the ablest ones are the ones that are in charge of the task or action but our brain is plastic and can rewire itself so that if we were to lose vision, for example, the visual cortex would be taken over by the sensory map, thus we would have a sharper touch sensitivity that would allow us to create a space image of our surroundings even if not disposing of our visual cortex.
Turning Our Ghosts Into Ancestors
This section of the book was dedicated to Mr.L, a patient who had lost his mother when he was 26 months old, summed up with the depression of his father after the mother’s dead, he had to autorregulate and turn off his emotions because a lack of proximity to family. Once he grew up he began having dreams about something lost but spoke about his mother’s death as though the pain did not register but still shocked him. He was married with children but still didn’t love them and all of that was linked to his past. Anyway if you want to know more about the story visit this page:
https://prezi.com/vptghtkfmjfc/ch9-turning-our-ghosts-into-ancestors/
What I could learn and what I consider to be the most important information of this chapter:
-Psychotherapy works by “talking to our neurons”, by shaping our thinking to turn on specific genes.
-Aplysisas’s (snail) molecular procedure from short-term memory to long-term: First protein Kinase A is released from the outer cell, then enters the nucleus of the nerve cell where genetical infomation is stored and turns on a certain gene which in turn changes the neuron ending structure, leading to the formation of new pathways.
I explained the procedure in aplysias because I believe human learning could be somewhat similar. The protein involved could be different in humans but at the end if we give an overall view to the process we can clearly see that is done with a purpose, that of changing the neuron structure so that it can expand to find more neurons and establish new non-existing neuronal connections. Although know that I’m thinking it through learning strenghtens connections but if we make new linkages from things we knew and recent learnings new connections are created.
-We have two types of memory: Procedural memory (Unconscious memory, non-verbal interactions and expressions) and Explicit memory (Helps us organize our memories by time and place with the help of language, developed in 26 months).
Rejuvenation
Here I’ll not make use of the book information but rather from self-learning. For a lot of time it was believed, even when neuroplasticity was discovered that old people’s brains didn’t have the capacity of rewiral or brain reorganization, that at a certain age the brain become fixed but we now know that that couldn’t be more wrong. It is a certainty that as we age we lose neurons but that doesn’t stop the brain to rewire itself, what young and old people need are challenges, novelty, new activities proven to increase cognitive behaviour. It is of crucial importance to be focused when doing that new activity or task, and it is of equally important that the task obliges us to be constantly challenged and to maintain our focus, otherwise it’ll be too boring and we’ll not make the most of it.
And as we now can see from brain scans, lots of old people who practice with cognitive improvement exercises on a daily basis preserve the brains they had when they were 20 years younger, and that is rejuvenation.
Author’s web page:
http://www.normandoidge.com/
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