CAN WE REALLY CHANGE?? AREN'T WE CREATURES OF HABIT? LOOK AROUND!!! PEOPLE, GENERALLY, AREN'T CHANGING MUCH!!! IS THERE HOPE?
READ ON!!!馃槉馃槉馃槉
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The brain weighs just three pounds, yet it’s one of the most advanced organs in the body. It has a hundred billion nerve cells, called neurons, and many more support cells. That’s equivalent to the number of stars in our galaxy.
Let’s start with the brain’s architecture. The neurons are clustered in the parts of the brain that have been called modules: the cortex (the outer layer, which has two hemispheres), the four lobes, and the subcortical (below the cortex) modules.
There has been a lot of hype about the character of the two halves of the brain. “Right-brain” people were said to be more creative, even more spiritual than “left-brain” people. The left-brain people were described as more rigid and picky. That hype, born in the 1970s, still exists, but many people who were instrumental in starting this fad have long since abandoned it. The truth is that the two hemispheres work together in everything you do. The brain contains a band of fibers called the corpus callosum that binds the two hemispheres together. It serves to connect distant neurons that fire together, adding dimension and depth to everything you do and think.
The corpus callosum of a woman is denser than that of a man. This means that the two hemispheres of a woman’s brain work more evenly together. The female brain is more symmetrical. The male brain has an asymmetrical torque, which means that the right frontal lobe is larger than the left frontal lobe, and the left occipital (back of the head) lobe is larger than the right occipital lobe.
For both sexes, the right hemisphere processes visual and spatial information, enabling you to grasp the “big picture.” The right hemisphere pays more attention to the context or the gist of a situation. The left hemisphere, in contrast, is more adept at details, categories, and linearly arranged information such as language. The right hemisphere is more active when you’re learning something new. Once the knowledge becomes routine and overlearned, the left hemisphere comes more into play. This is another reason that language is processed by the left hemisphere.
The right hemisphere makes better connections with the parts of the brain below the cortex, so it is more emotional by nature. In other words, it’s better able to pick up the emotional climate of a conversation. Since women’s brains have a better connection between the two hemispheres than men’s brains do, women are said to be more intuitive. Words often carry more emotional meaning for women than they do for men.
There are four lobes in each hemisphere: the frontal lobe, the parietal (middle) lobe, the temporal (side) lobe, and the occipital lobe. Each has specific talents. For example, when you appreciate a specific object, such as a chair you sat on at your friend’s house, the thoughts and feelings you have about the chair are dispersed throughout your brain. You remember the elegant shape of the chair through your right parietal lobe. You remember the words your friend used to describe his trip to Costa Rica through your left temporal lobe, and you process the tone of his voice through your right temporal lobe. You remember looking back at the chair as you were leaving the room and noticing its deep cinnamon color through your occipital lobe.
Women have a greater density of neurons in the temporal lobe, which specializes in language. This verbal advantage begins to appear during the first two years of life, when little girls develop the ability to talk about six months earlier than little boys do. When developing verbal strategies, women activate the left hippocampus (a part of the brain related to memory) more than men do.
Men generally have greater visual and spatial skills, because they show greater activity in the right hippocampus than women do. Then there is the frontal lobe, which makes up about 20 percent of the human brain. In comparison, the frontal lobe of a cat occupies about 3.5 percent of its brain. The frontal lobe is the last part of the brain to mature in humans; its development is not complete until sometime in the third decade of life.
At the forefront of the frontal lobe, the prefrontal cortex (PFC) gives us many of our most complex cognitive, behavioral, and emotional capacities. The PFC enables you to develop and act on a moral system, because it allows you to set aside your needs and reflect on the needs of others. The PFC is part of a system that provides you with the capacity for empathy. If your PFC is damaged, you are likely to engage in antisocial and impulsive behaviors or not engage in any purposeful behavior at all.
One of the principal parts of the PFC is the dorsolateral prefrontal cortex (DLPFC). Dorsal means “fin” or “top,” and lateral means “side.” The other significant prefrontal area is called the orbital frontal cortex (OFC), because it lies just behind the orbs of the eyes.
The DLPFC is very involved in higher-order thinking, attention, and short-term memory (which is also called working memory because it processes what you are working on at any one time).
You can usually hold something you’re working on in your mind for twenty to thirty seconds. The DLPFC is the last part of the brain to fully develop, and it is also the earliest to falter during the later years of life. This is what’s behind the phenomenon of walking purposely into a room and then forgetting what you intended to do there. The DLPFC is involved with complex problem solving, so it maintains rich connections with the hippocampus, which helps you to remember things for later.
The OFC, in contrast, appears to have a closer relationship with the parts of the brain that process emotions, such as those generated by your amygdala. The OFC develops earlier in life and is closely associated with what is called the social brain. Without your OFC, you would be like the classic case of Phineas Gage. In an accident at work, a steel rod pierced Gage’s brain and skewered his OFC but left everything else in his brain intact. Gage retained his cognitive abilities but lost much of his ability to inhibit impulses. He had previously been a supervisor who was widely respected, but now he became unstable (in stark contrast to his previous emotional reserve), erratic, rude, and hard to get along with. Gage was eventually reduced to working in a circus freak show, and he died penniless in San Francisco twenty years after the injury. His skull is on display at Harvard Medical School.
Highly influenced by bonding, the OFC thrives on close relationships. If those relationships are trusting and supportive, the OFC becomes more capable of regulating your emotions. In contrast to the DLPFC, the OFC does not falter much in old age. Older adults remember faces as well as younger adults do.
Finally, there are differences between the left and the right pre-frontal cortex. The right PFC helps to develop foresight and to get the gist of what’s happening in a given situation. It helps you to make plans, stay on course toward your overall goal, and understand metaphor. If someone says, “Michael Phelps is a fish,” it’s your right PFC that enables you to understand what this person is really saying about the Olympic swimmer. Your left PFC, in contrast, helps you to focus on the details of individual events, like how many points were scored in the second half of a football game.
Within all these lobes, hemispheres, and modules are a hundred billion neurons waiting to be used. They are highly social; if they weren’t used by working with neighboring neurons, they would die. Each neuron is capable of maintaining connections with about ten thousand other neurons. These connections change as you learn things, such as a new tennis swing, a new language, or the layout of a new supermarket.
Neurons function partly on chemistry and partly on the electrical firing of impulses in an on-and-off manner. Neurons communicate with one another by sending chemical messengers called neurotransmitters across a gap called a synapse. This is how one neuron gets another neuron to fire. More than sixty types of neurotransmitters exist in the brain. Some make you excited, and some calm you down. There are many different shapes and sizes of synapses, and the shape and size of a synapse changes as you learn something new.
Two neurotransmitters account for about 80 percent of the signaling in the brain: glutamate,
which is excitatory and stirs activity, and gamma-aminobutyric acid (GABA), which is inhibitory and quiets down activity. Glutamate is the workhorse in the brain. When it delivers a signal between two neurons that previously had no connection, it primes the pump for later activation. The more times this connection is activated, the stronger the wiring is between these neurons. GABA, in contrast, helps to calm you down when you need to be calm. It is the target of drugs like Valium and Ativan, which used to be prescribed as a panacea for anxiety. You need optimum GABA activity to keep your anxiety down, but you don’t need those drugs. Although glutamate and GABA are the principal neurotransmitters, there are scores of others that play important roles in the brain. They account for only a fraction of the activity between the neurons, but they have a powerful influence on those neurons. They are widely researched, and many drugs have been designed to affect them.
The three most researched neurotransmitters are serotonin, norepinephrine, and dopamine, and they are sometimes called neuromodulators because they alter the sensitivity of receptors, make a neuron more efficient, or instruct a neuron to make more glutamate. They can also help to lower the “noise” in the brain by working to override other signals that are coming into the synapse. Sometimes, however, they intensify those other signals. These three neurotransmitters can either act directly, like glutamate and GABA, or fine-tune the flow of information that is being processed in the synapses.
Serotonin has attracted much publicity because of the widespread use of drugs like Prozac.
Serotonin plays a role in emotional tone and in many different emotional responses. Low serotonin levels are correlated with anxiety, depression, and even obsessive-compulsive disorder (OCD).
Serotonin is like a traffic cop, because it helps to keep brain activity under control. It’s common to hear people who take drugs like Prozac say, “Things don’t bother me the way they used to.”
However, there is also a downside: these drugs generally provide such an even keel that people say, “I know that the beauty of that sunset would’ve had a bigger effect on me in the past, but now I’m sort of numb to things like that.”
Norepinephrine activates attention. It amplifies the signals that influence perception, arousal, and motivation. Like serotonin, norepinephrine has been associated with mood and depression. It has been targeted by antidepressants such as Ludiomil and Vesta.
Dopamine sharpens and focuses attention. It has also been associated with reward, movement, and learning, and it is one of the principal neurotransmitters that code pleasure. When registering pleasure, dopamine activates an area called the nucleus accumbens, sometimes referred to as the pleasure center. Activation of the nucleus accumbens has been associated with drug abuse, gambling, and other types of addictive behaviors. When this area is frequently activated, it becomes hard to stop doing the things that activate it.
Drugs that activate dopamine, like Ritalin, are used to help people with attention-deficit/hyperactivity disorder (ADHD). People (usually children and adolescents) who are given Ritalin or similar drugs not only pay attention better but also report feeling calmer.
In the last twenty years, there has been an overwhelming amount of evidence that the synapses are not hardwired but are changing all the time. This is what is meant by synaptic plasticity, or neuroplasticity . The synapses between the neurons are plastic.
Neuroplasticity is what makes memory possible, the brain changes its synapses when you remember something new. The brain would not be able to record anything new if it were hardwired.
Remembering something new is, therefore, rewiring the brain. By making connections between ideas or images, you also make connections between the neurons that encode those ideas and images.
Neuroplasticity illustrates the phrase “Use it or lose it.” When you use the synaptic connections that represent a skill, you strengthen them, and when you let the skill lie dormant, you weaken those connections. It’s similar to the way that your muscles will weaken if you stop exercising.
“Cells that fire together wire together” aptly describes the way your brain reorganizes when you have new experiences. The more you do something in a particular way, use words with a specific accent, or remember something about your past, the more the neurons that fire together to make this happen will strengthen their connections. The more the neurons fire together, the more likely it is that they will fire together in the future.
Just as “Cells that fire together wire together” has become a sort of mantra in neuroscience, so too has an opposite phrase been coined: “Neurons that fire apart wire apart.” This means that neurons that are out of sync will fail to link. It is the neural explanation for forgetting.
In other words, the more you do something, the more likely it is that you will do it again in the future. That’s why baseball players go to batting practice, golfers go to driving ranges, and piano players practice for hours on end. The same goes for thinking. The more you think about your Aunt Matilda, the more she will pop into your mind again and again. Repetition rewires the brain and breeds habits.
When neurons fire together often, they begin to fire together at a quicker rate. This leads to increased efficiency, because there is more precision in the number of neurons that are required to do a particular skill. For example, when you learned to ride a bicycle, you used more muscles and neurons at first as you wobbled; then, once you learned to ride efficiently, less muscular effort and fewer neurons were required, and your ride was much smoother and faster. The neurons that were required to fire with their partners had teamed up and wired together.
As you become more talented at a specific skill, a greater amount of space in your brain is devoted to making that possible. Alvaro Pascual-Leone of Harvard Medical School used transcranial magnetic stimulation (TMS) to measure specific areas of the cortex. He studied blind people who read braille and found that the cortical maps for their reading fingers were larger than the cortical maps for their other fingers and also for the fingers of sighted readers. In other words, the sensitivity of their reading fingers required more space. Thus, cultivated movement enhances neuro-plasticity, which creates extra space in the brain.
In another example of the power of neuroplasticity, musicians who play string instruments were fewer neurons were required, and your ride was much smoother and faster. The neurons that were required to fire with their partners had teamed up and wired together.
As you become more talented at a specific skill, a greater amount of space in your brain is devoted to making that possible. Alvaro Pascual-Leone of Harvard Medical School used transcranial magnetic stimulation (TMS) to measure specific areas of the cortex. He studied blind people who read braille and found that the cortical maps for their reading fingers were larger than the cortical maps for their other fingers and also for the fingers of sighted readers. In other words, the sensitivity of their reading fingers required more space. Thus, cultivated movement enhances neuro-plasticity, which creates extra space in the brain.
In another example of the power of neuroplasticity, musicians who play string instruments were examined to see if their brains had reorganized to accommodate more space. There was no difference between the string-instrument players and the nonmusicians in how much space was made available in the sensory motor strip (the area in the center of the brain that controls movement and physical sensation) for the fingers of the right hand (in right-handed players). However, the area of the brain devoted to the fingers of the left hand (in right-handed players) showed a dramatic difference. The fingers of the left hand must be nimble and dexterous in order to make all the fretting movements. The cortical space devoted to the fingers involved in fretting was significantly greater in these musicians than in nonmusicians. This difference was greatest if the musician had started playing the instrument before the age of twelve. In other words, although this use-dependent neuroplasticity occurs during adulthood, it is more dramatic the earlier and the longer that the person plays the instrument. Not only does behavior change the structure of the brain through neuroplasticity; just thinking about or imagining particular behaviors can change brain structure as well. For example, researchers have shown that simply imagining a session of piano practice contributes to neuroplasticity in the area of the brain associated with the finger movements of playing the piano. Thus, mental practice alone contributes to the rewiring of the brain.
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Mussar Haskels:
1] 诪讛 专讘讜 诪注砖讬讱 讛砖诐!!!!! The wonders of the human brain!!!!!!! 驻诇讗讬 驻诇讗讬 驻诇讗讬 驻诇讗讬 驻诇讗讜转!!!
2] YOU CAN CHANGE!!! Science proves it!!! 讻讬讛讜讚讛 讜注讜讚 诇拽专讗 b/c we already know this from the Torah!!馃槉馃槉
