THE HUMAN BRAIN
The following summary was taken from:
“The Human Brain” published in London in 2009 by Rita Carter with several contributors. She is a science and medicine writer, and had as consulters, Professor Chris Frith, Emeritus Professor of Neuro-Psychology of U. College of London, U.K. and Uta Frith, Emeritus Professor of Cognitive Development from the same College. The book is composed of mostly photos, drawings and scans with respective written facts at the side. NO PERMISSION WAS OBTAINED FROM THE AUTHOR TO COPY THESE FACTS.
The reasons behind DOING THIS SUMMARY are double:
1. I was amazed at the amount of information with actual MRI’s depicting areas of increased activity in human brains from different studies. I believe all of us must understand better our computer in order to keep vigilance and take our blood pressures daily after the age of 40, keep a log of them, and show it to our physicians for further advice when elevations are prolonged. This advice was given to my husband in 1996 in a regional center for stroke for Northern Ohio, Case Western Reserve University. It was given by a lady Neurology Professor to medical students making rounds with her and next to my husband’s bed who had suffered a TIA, or a Transient Ischemic Attack with a transient paralysis of one side of his body.
This is directly related to very hi blood pressures because the wall of the arteries of the brain when scourged with very high pressures 60 to 90 times per minute….!!!, enter into a spasm and this renders the part of the brain irrigated by that artery into deep ischemia (lack of oxygen). Or, the very hi blood pressure can burst a weakened part of the arterial wall and the person may have a massive hemorrhage, which causes major damage due to the high pressure of the volume of blood on different parts of the brain that are compressed against the bone of the skull.
Needless to say, since I heard the advice in 1996, I have followed it and have used Omron blood pressures machines which give me a digital read-out. They are rather cheap and available everywhere, from Walmart, Target and the like to all pharmacies.
2. The second reason and actually as important, is because I want to reveal details of this our computer/brain to all of you so that you can sense the glory of God in every detail of the anatomy and physiology of this organ… and thank Him for having one of these divine devices helping you to work and write and love and do good if you choose to…! You will never be the same when you learn more details about what you house in your head…!
FROM THE BOOK “The Human Brain”:
The human brain is like nothing else. It is not especially prepossessing – 3 lb or so of rounded corrugate flesh with a consistency somewhere between jelly and cold butter. It is perhaps not surprising that for centuries the contents of our skulls were regarded as relatively unimportant. When they mummified their dead, the ancient Egyptians scooped out the brains and threw them away, yet carefully preserved the heart. Aristotle thought the brain was a radiator for cooling the blood. Descartes gave it a little more respect, concluding that it was a sort of antenna by which the spirit might commune with the body. It is only now that the full wonder of the brain is being realized.
The most basic function of the brain is to keep the rest of the body alive. Among the brain’s 100 billion neurons, there are more potential connections between them than there are atoms in the Universe. A fetus grows neurons at a rate of 250,000 a minute. A person is born with nearly all the neurons of an adult, but the neural networks are not matured yet. Information travels at different speeds within different types of neurons. Transmission speeds range from 3 to 330 feet/second or 1 to 100 meters/second.
Some neurons regulate your breathing, heartbeat and blood pressure and others control hunger, thirst, and sex drive and sleep cycle. In addition, the brain generates emotions, perceptions and thoughts that guide your behavior. Then, it directs and executes your actions. Finally, it is responsible for the conscious awareness of the mind itself.
Roughly, 10% of the 100 billion neurons are specialized electrical cells that send signals to one another; this signal transmission makes brain function different from any other bodily process. Although the signals are electrical, the mode of transmission between cells is chemical through substances called neurotransmitters.
The basic blueprint of the brain is dictated by our genes. As with any other body feature, brains share a basic anatomy, but each one is also unique. Even identical twins have visibly different brains from the time they are born. The difference between individual brains results in each person having a unique personality. (Notice how this scientific description cannot but assert that we are unique… from birth… with a unique personality, or unique dignity…)
Brain tissue can be “strengthened” and built up like a muscle according to how much it is exercised. So, if a person learns and practices a skill, such as playing a musical instrument or doing mathematics, the part of the brain concerned with that task will grow physically bigger. It also becomes more efficient and enables he person to perform the task more skillfully. This is called plasticity.
Glucose is the brain’s sole fuel, except under conditions of starvation, when it breaks down protein. The brain is by far the body’s hungriest organ. It accounts for just 2 % of the body’s weight but it requires a staggering 20% of its total glucose supplies. The brain cannot store glucose, so it must be available at all times via the blood supply. Without oxygen or glucose, the brain can last for only about 10 minutes.
The brain has a complex and many layered anatomy. Brain anatomy is hidden, secret, and more complex than any other part of the body. Neurons form larger structures called nuclei (30 sets, right and left) that carry out particular functions. They also cluster together to form the thick, laminated, sheet of gray matter forming the covering of the brain called the cortex. Deep fissures in its surface divide the brain into two halves (the hemispheres). Each with five lobes. These major divisions “specialize” in different tasks, but also interconnect and interact.
1. The hemispheres are linked by a bridge of nerve fibers, the corpus callosum.
2. They wrap around the thalamus, hypothalamus known as the forebrain.
3. Below the forebrain is the midbrain, with small divisions that form the basal ganglia.
4. Below the midbrain is the hind brain with the pons and beneath are the cerebellum and the medulla, which tapers to merge with the spinal cord.
Among the 30 sets of nuclei, the main ones are:
Basal: specialized in motor control and learning
Caudate: specialized in motor control and learning but especially controlling feedback.
Sub-thalamic: they are implicated in impulsive actions, including obsession-compulsion
Thalamus: a major processing and relay area for inputs to the cerebral cortex.
Amygdala: part of the limbic system, it is involved in learning, memory and emotions
Facial nucleus: one of several paired brainstem nuclei for cranial nerves, in this case nerve VII (facial nerve)
Hypothalamus: Not much larger than the end segment of the little finger, weighing about 4 grams, comprising only 0.4 % of the brain volume, has many and varied vita roles in conscious behavior, emotions and instincts, and automatic control of body systems and processes like the endocrine system via the a pea-sized cluster of cells called pituitary gland that lies just below it. The hypothalamus secretory cells make hormones but its neuro-secretory cells produce hormone like substances that travel along nerve axons to the pituitary gland. Examples of hormones: anti-diuretic hormone and oxitocyn, the birth and breastfeeding hormone.
Summary of functions of different parts of the brain
1. The uppermost brain region, the cerebral cortex, is mostly involved in conscious sensations, abstract thought processes, reasoning, planning, working memory, and similar higher mental processes.
2. The limbic areas on the brain’s innermost sides around the brainstem deal largely with more emotional and instinctive behaviors and reactions, as well as long-term memory.
3. The thalamus is a preprocessing and relay center, primarily for sensory information coming from lower in the brainstem, bound for the cerebral hemispheres above.
4. Moving down from the brainstem into the medulla are the so-called “vegetative centers” of the brain, which sustain life even if the person has lost consciousness.
The brainstem is perhaps misnamed. It is not a stem leading to the separate brain above, but an integral part of the brain itself. It is shaped rather like a widening upright stalk, on top of which are the thalamus and the dome of the cerebral hemispheres. Curled around the lowers brainstem at the rear of the brain, sits the cerebellum
It is also the site of subconscious or autonomic control mechanism, of which we are usually unaware. It also houses groups of nuclei that are centers for breathing, cardiac pulse, blood pressure as well as vomiting, sneezing, swallowing and coughing.
Circadian rhythm: Information from the “body clock” is passed to the brainstem so that basic processes follow a 24-hour rhythm. About a third of life is spent asleep, during which time the brain remains active, fulfilling a range of important functions. During sleep, the brain generates dreams, which provide us with some of the most intense and strange experiences that we have.
Star of the day: 6:00 AM
6:45 – sharpest rise in blood pressure
7:30 – melatonin excretion stops
8:30 – bowel movement likely
9:00 – highest testosterone secretion
10:00 – high alertness
14:30 – best coordination
15:30 – fastest reaction time
17:00 – greatest cardiovascular efficiency and muscle strength
18:30 – highest blood pressure’
19:00 – highest body temperature
21:00 – melatonin secretion starts
22:30 – bowel movements suppressed
2:00 – deepest sleep
4:30 – lowest body temperature
The brain: it has two types of dreaming:
1) During deep sleep we have vague, often emotionally charged and nonsensical dreams that are often forgotten immediately. The brain is not very active, but seems to be gently processing information in order to lay it down in memory.
2) In REM sleep the brain becomes very active and produces vivid, intense “virtual realities” typically with a narrative. The part of the brain that processes sensation is very active during REM dreaming. The frontal lobes, which include areas that apply critical analysis to our experience, are effectively turned off, so when strange events happen in our dreams we just accept them. (I suspect that St. Joseph’s dream must have been in the REM category…!)
5. The cerebellum main functions are to coordinate body movement through integrated control of muscles, including balance and posture, and equilibrium.
Left and right
Structurally, the left and right cerebral hemispheres look broadly similar. Functionally, however, speech and language, stepwise reasoning and analysis, and certain communication actions are based mainly on the left side in most people. Since nerve fibers cross from left to right at the base of the brain, this dominant left side receives sensory information from, and sends messages to, muscles in the right side of the body- including the right hand.
Meanwhile, the right hemisphere is the more concerned with sensory inputs, auditory and visual awareness, creative abilities and spatial-temporal awareness (what happens in our surroundings second by second). Those people are left handed.
HOW WE SENSE THE WORLD
The brain reaches out to the environment via our sense organs, which respond to various stimuli such as light, sound waves, and pressure. The information is transmitted as electrical signals to specialized areas of the cerebral cortex (the outer layers) to be processed into sensations such as vision, hearing and touch.
Sensory neurons respond to data from specific sense organs. Visual cortical neurons, for example, are most sensitive to signals from the eye. But his specialization is not rigid. Visual neurons have been found to resend more strongly to weak light signals if accompanied by sound, suggesting that they are activated by data from the ears as well as the eyes.
Conscious and unconscious sensation
Our brains are bombarded with sensory information, but only a fraction of it reaches consciousness. Most sensory signals fizzle out unnoticed. Especially “loud” or important data grabs our attention and we become conscious of it. Sensations that we are not conscious of, may still guide our actions. For example, unconscious sensations relating to our body position allow us to move without thinking about it. Also, sights and sounds that we fail to notice may nevertheless influence our behavior.
Bottom-up and top-down processing
Sensations are triggered externally, by an occurrence that impacts on a sense organ, and internally, by memory or imagination. The former is known as ‘bottom-up” and the latter as “top-down” processing. The two combine to create our experience of reality. Each person’s experience of a given event is different. Physiological differences affect bottom-up processing. An individual’s own memories, knowledge, and expectations affect top-down processing. Or, the bottom-up processing presents the viewer with a meaningless array of seemingly random blobs and shapes. The top-down processing imposes a pattern on the image that helps the viewer understand it and see a bird for example. `
Laugher plays tricks on the eyes
Laughing literally changes the way you see the world. Normally, when you look at a Necker cube the image switches between two competing 3-D images, a situation known as binocular rivalry. This rivalry occurs because each eye sends a slightly different image to each side of the brain and the brain switches conscious awareness of one to the other. One theory on why switching stops during laughter is that amusement is a state in which information from both halves of the brain merges more than usual.
THE EMOTIONAL BRAIN
Emotions may seem to be conscious feelings, but they are, in fact, “inner motions” – Physiological response to stimuli, designed to push us away from danger and toward reward. Emotions are generated constantly, but much of the time we are unaware of them.
THE SELF AND OTHERS – THE SOCIAL BRAIN
One of the most distinctive features of the human brain is the large area of neocortex. One reason for the substantial growth of the neocortex may be that humans adapted this way in response to the demands of living in large, close-knit groups. In primates the size of the neocortex relative to other brain areas increase in almost direct proportion to the average size of the social group. Social awareness covers a wide range of cognition that generates a sense of a “self” as well as of that self in a social context. For example, we adapt our behavior to cooperate with others.
The pain of rejection: in a study, MRI scans were conducted on people playing a virtual ball game from which trey were progressively excluded. Upon awareness of rejection, the anterior cingulated cortex was activated, an area that also registers body pain, suggesting that the emotional impact of the two is similar. Part of the prefrontal cortex that helps control emotions was also activated, which seemed to reduce feelings of rejection.
THE MORAL BRAIN
Our sense of right and wrong permeates all our social perceptions and interactions. Moral decision-making is partly learned, but it also depends on emotions, which give “value” to actions and experiences. When making moral judgments, two overlapping but distinct brain circuits come into play. Ones is a “rational” circuit,” which weighs up the pros and cons of an action objectively. The other circuit is emotional. It generates a fast and instinctive sense of what is right and wrong. The two circuit’s do not always arrive at the same conclusion, because emotions are biased toward self-survival and/or protecting those who are loved or related to oneself. (My take: there we see the part of the brain that favors our self-will that always seek control).
Psychopaths and bullies: They are defined as people who use manipulation, intimidation and violence to control others and satisfy selfish needs. They display an inability to feel guilt, remorse, or anxiety about their antisocial behavior. This may result from damage or developmental problems involving the moral circuits of the brain. Imaging studies have found that psychopaths show low levels of activity in the amygdala when faced with stimuli that would be emotionally traumatic to others and normally general amygdala activation. (The book show MRI’s of people that when seeing pictures they had learned to associate with fear and psychopaths showed much less activity in the amygdala than normal people).
LANGUAGE AND COMMUNICATION
We signal our thoughts, feelings and intentions by gesture and body language as well as by speech. Half of our communication is typically nonverbal and when they conflict, gestures “speak” louder than words. When body language and facial expression from another person do not match each other, we are biased toward the emotion signaled by the body, rather than the expression of the face.
The three principal language areas are usually found in the left hemisphere, while four other important language areas are located in the right hemisphere.
Left hemisphere regulates: articulating and comprehending language and word recognition.
Right hemisphere regulates: recognizing tone, rhythm stress and intonation; recognizing the speaker and recognizing gestures.
Main language areas: language recognition occurs mainly in Broca’s and Wernicke’s areas. Broadly speaking, words are comprehended by Wernicke’s area and articulated by Broca’s. A thick band of tissue called the “arcuate fasciculus” connects these two areas.
Wernicke’s area is surrounded by an area known as Geschwind’s territory. When a person hears words spoken, Wernicke’s area matches the sound to their meaning, and special neurons in Geschwind’s territory are thought to assist by combining the many different properties of words (sound, sight and meaning) to provide full comprehension. When a person speaks, the process happens in reverse. Wernicke’s area finds the correct words to match the thought that is to be expressed. The chosen words then pass to Broca’s area via the arcuate fasciculus. Broca’s area then turns the words into sounds by moving the tongue, mouth and jaw into the required position and by activating the larynx.
The Broca’s area lies in the frontal lobe. The back region moves the mouth to form words, while the front part is thought to be concerned with aspects of word meaning. Wernicke’s area lies in the upper temporal love, adjacent to the occipital and parietal cortices; heard and seen words are understood there and also selected for articulation. The Geschwind’s territory is located in the lower part of the parietal lobe, where information from sound, sight and body sensation comes together. It is one of the last parts of the brain to mature. (My note: Wow, wow, wow!!!)
Unlike the rules of speech, which vary from language to language, gesturing seems to have a universal “grammar”. Asked to communicate a simple statement using words of their native languages, English, Chinese and Spanish speakers started with the subject, then the verb and finally the object, whereas Turkish speakers use the subject, object and then the verb. However, when just using gestures, speakers of all of these languages placed the subject, object and verb in that order.
Three main categories of gestures: natural gestures tend to be used for three main purposes: to tell a story, to convey a feeling or idea, or to emphasize a spoken statement. Examples:
Protesting innocence: Arms wide and hands open, with body exposed says: “I’m not hiding anything or deceiving you.”
Shock: both hands covering the mouth
Annoyance: an aggressive, rigid one hand movement elevated to the mid-chest with a finger towards another suggests anger or rejection.
Jubilation: Rising of both hands full height with clenched fists. (what we see after a touch down…!)
Reinforcing a point: pulling fingertips together suggest accuracy, cohesion, and concentration; me be used to focus listener’s attention on words.
Mirroring parents: By 3 months old, babies have the ability to follow another person’s eye gaze, and they are quick to pick up any emotion contained in a look. Experiments show that if a parent looks toward something and displays fear, for example by widening their eyes, the child is very likely to mirror this reaction and be scared too, even if the object is clearly harmless.
LANGUAGE PROBLEMS: aphasia is usually with brain injury (such as a stroke), which affects the brains’ language areas. Depending on the type of damage, the area affected and the extent of damage, those suffering from aphasia may be able to speak, yet have little or no comprehension of what they or others are saying. Or they may be able to understand language, yet be unable to speak. Sometimes, sufferers can sing but no speak, or write but not read.
The multilingual brain: being fluent in two languages, particularly from early childhood, enhances various cognitive skills and might also protect against the onset of dementia and other age-related cognitive decline. One reason for this may be that speaking a second language could build more connections between neurons. Studies show that bilingual adults have denser gray matter, especially in the inferior frontal cortex of the brain’s left hemisphere, where most language and communication skills are controlled.
Conversation comes naturally to most of us, but in terms of brain function it is one of the most complicated cerebral activities we engage in. Both speaking and listening involve widespread areas of the brain reflecting many different types and levels of cognition.
Listening: the sound of spoken words take a short time – about 150 milliseconds (ms) – to pass from the speaker’s mouth to the listener’s ear, and for the ear to turn this stimulus into electrical signals, and for this to be processed as sound by the auditory cortex. These are all the steps:
1. 50-150 ms for the sound to be registered in the auditory cortex and be distributed to areas concerned with decoding the words and other areas of the brain involved with emotion, tone and rhythm.
2. 150-200 ms are used for the amygdala to pick up on the emotional tone of the speech and subsequently produce and appropriate emotional reaction.
3. 250-300 ms takes for the speech to be decoded in Wernicke’s area in the left hemisphere. Then, the anterior temporal love and the inferior frontal cortex in both hemispheres start to extract the meaning of the word.
4. 4 00-550 ms. Turning the sound of speech into a stream of meaning requires more than just decoding the words – they also have to be associated with memories to give full comprehension. This takes place in part of the frontal lobe.
Speaking: the speech process starts about a quarter of a second before words are actually uttered. This is when the brain starts to select the words that are to convey whatever the person wants to say. The words then have to be tuned into sounds, and are finally articulated.
1. 250 ms. Before speaking, words are attached to memories and ideas and act as “handles” by which the brain can grasp the correct ones to express an idea. The matching of words to concepts happens in the temporal lobe.
2. 200 ms – Shortly after the words have been retrieved from memory, they are matched to the sounds in Wernicke’s area, which is adjacent to the auditory cortex where sounds are distinguished. Prepared words are transmitted to Broca’s area via the “arcuate fasciculus.”
3.150 ms – The neurons in Broca’s area match the sounds of words to the specific mouth, tongue and throat movements required to actually voice them.
4. The mouth, tongue and throat movements needed to articulate the selected words are directed by the part of the motor cortex that controls these parts of the body.
5. Under 100 ms are needed for fine control of articulation. The cerebellum is concerned with orchestrating the timing of speech production. The right cerebellar hemisphere connects to the left cerebral hemisphere and this shows greatest activation during speech, whereas the left cerebellar hemisphere is more active during singing.
READING AND WRITING
Learning to read and write uses even more of the brain. In addition to the language areas concerned with comprehension, and the visual areas concerned with decoding text, writing involves integrating the activity in these areas with those concerned with manual dexterity, including the cerebellum, which is involved with intricate hand movements.
Reading in your mother tongue: languages are stored in separate areas in the brains of bilingual people, which mean that different groups of neurons are used to generate each language. This prevents the two languages from interfering with one another. Damage to one area of the brain can results in the complete loss of one language, while the other remains intact. The brain treats a second language learned later in life differently from the mother tongue. A language absorbed from infancy has wider and more intense associations than a second language.
How literacy affects the brain: literacy may improve the ability to make fine distinctions between spoken sounds. Tests have shown that when literate people hear a spoken sound that they do not recognize as a word, a wider network of brain areas becomes active than in those who cannot read or write.
THE PRINCIPLES OF MEMORY
A memory may be of various kinds: ability to recall a poem, to recognize a face on demand, or a vague vision of some long past event; the skill required to ride a bike; of the knowledge that your car keys are on the table. But all these phenomena have in common that they involve learning and total or partial reconstruction of a past experience.
Types of memory: THERE ARE FIVE DIFFERENT TYPES.
1. Episodic memory: it comprises reconstruction of past experiences, including sensations and emotions; these usually unfold like a movie and are experienced from one’s own point of view.
2. Semantic memory is non-personal, factual knowledge that “stands alone”.
3. Working memory: is the capacity to hold information in the mind for just long enough to use it.
4. Procedural “body” memories comprise learned actions, such as walking, swimming, or riding a bicycle.
5. Implicit memories are those we do not know we have. They affect our actions in subtle ways. For example, you might take and inexplicable dislike to a new person because they remind you of someone nasty.
Thalamus: directs attention
Cerebellum: associated with conditioned memories – events linked by time. Body skills depend on the cerebellum to direct timing and coordination.
Parietal lobe: associated with spatial memories
Caudate nucleus: associate with memories of instinctive skills
Mamillary body: associated with episodic memories.
Frontal lobe: seat of working memory. Activity here ensures that episodic memories are not mistaken for real life. One part of the frontal lobe, the central executive, holds a plan of action while calling up items from the rest of the brain.
Putamen: associated with procedural skills. They are body memories that allow to carry out ordinary motor actions automatically, once we have learned them, like riding a bike.
Amygdala: emotional memories may be stored here
Temporal lobe: holds general knowledge
Hippocampus: EVENTS ARE TURNED INTO MEMORY HERE. This is the most essential part for the storage of memory of any kind. During memory recall, the hippocampus is busy pulling together the various facets of the memory from widely distributed areas of the brain.
Forming a long term memory
1. 0.2 sec. The brain can absorb only a finite amount of sensory input at any point. It can sample a little input about several events at once, or focus attention on one event and extract lots of information from that alone. Attention causes the neurons that register the event to fire more frequently and this makes the experience more intense; it also increases the likelihood that the event will be encoded as a memory.
2. 0.25 sec. Personal interactions and other emotional events “grab” attention, so are more likely to be stored.
3. 0.5 sec to 10 minutes. Short-term or “working” memory is like a text on a blackboard that is constantly refreshed.
4. 10 min to 2 years. Particularly striking events “break out” from working memory and travel to the hippocampus, where they undergo further processing and these neurons star to encode this information permanently.
5. 2 years onward. It takes up to 2 years for a memory to become firmly consolidated in the brain, and even after that it may be altered or lost. During this time, the neural firing patterns that encode an experience or event are played back and forth between the hippocampus and the cortex. This prolonged repetitive “dialogue” causes the pattern to be shifted from the hippocampus to the cortex; this may happen in order to free up hippocampal processing space for new information. The dialogue takes place largely during sleep. The quiet or slow/wave phase of sleep is thought be be more important than the rapid eye movement sleep.
Intelligence refers to the ability to learn about, learn from, understand and interact with one’s environment. It involves:
1. Physical dexterity
2. Verbal fluency
3. Concrete and abstract reasoning (making decisions)
4. Sensory discrimination
5. Emotional sensitivity
7. Ability to function well in society.
The frontal lobes have long been considered the seat of intelligence since damage to them affects the ability to concentrate, make sound judgments, and so-on. However, recent research suggests that intelligence relies on a neural “superhighway” that links the frontal lobes, which plan and organize, with the parietal lobes, which integrate sensory information. The speed and efficiency with which the frontal lobes receive a stream of ready-to-use data via this route may affect the IQ.
We cannot do two things at once
If you try to do something while still working on a previous task, your brain stalls. This may be because the prefrontal cortex, which disengages attention from one task and switches it to another, cannot do so instantly, resulting in a short “processing gap.” The brain needs a minimum of 300 milliseconds to switch from one distinct task to the next. The “processing gap” makes a task combination such as talking on a phone while driving, potentially lethal…!!!
I could write more and more but it would be too much for me and for you. I will only enumerate other activities that our brains deal with… All of them are simply extraordinary topics.
1. Creativity and humor
2. What is consciousness?
3. Influencing the brain.
a) Differences between men and female brains
b) The gendered brain: I must note here that this book shows scans of brains from heterosexual and gay persons. It says that heterosexual men tend to have asymmetric brains, with the right hemisphere slightly larger than the left, and this has been found in brains from gay women. In the other hand, heterosexual women show patterns of brain connectivity that are similar to gay men, particularly in areas involved with anxiety, and the scans in this book show the difference clearly.
c) Cultural influences
4. Personality markers: extroversion, aggression, social behavior, novelty seeking, cooperation, optimism, many personalities.
5. The aging brain
a) Natural degeneration
b) Positive aging
c) Keeping the brain young
6. Diseases and disorders of the brain
7. A vulnerable brain because of its plasticity I have treated this subject matter extensively in a previous blog, but I want to copy here what even a scientist from San Francisco has said regarding our wonderful brains and how the media reorganize it.
From Dr. Michael Merzenich – 2005 – “The Internet is just one of those things that contemporary humans can spend millions of “practice” events at, that the average human a thousand years ago had absolutely no exposure to. Our brains are massively remodeled by this exposure, but so, too, by reading, by television, by video games, by modern electronics, by contemporary music, by contemporary “tools, etc.”
Television watching, one of the signature activities of our culture, correlates with brain problems. A recent study of more than 2,600 toddlers shows that early exposure to television between the ages of one and three, correlates with problems paying attention and controlling impulses later in childhood. For every hour of TV the toddlers watched each day, their chances of developing serious attention difficulties at age seven, increased by 10%. (However, this study did not perfectly control other possible factors influencing correlation between TV and later attention problems).
Video games, like Internet porn, meet all the conditions for plastic brain map changes. A team at Hammersmith Hospital in London designed a typical video game in which a tank commander shoots the enemy and dodges enemy fire. The experiment showed that dopamine – the reward neurotransmitter, also triggered by addictive drugs – is released in the brain during these games. People who are addicted to computer games show all the signs of other addictions; cravings when they stop, neglect of other activities, euphoria when on the computer, and tendency to deny or minimize their actual involvement.
Marshall McLuhan, the Canadian who founded media studies in the 1950’s and predicted the Internet 20 years before it was invented, was the first to intuit that the media change our brains irrespective of content. He argued that each medium reorganizes our mind and brain in its own unique way and that the consequences of these reorganizations are far more significant than the effects of the content or “message.” McLuhan’s insight was that the communication media both extend our range and implode into us. His first law of media is that all the media are extensions of aspects of man. The telegraph, radio and telephone extend the range of the human ear; the television camera extends the eye and sight; the computer extends the processing capacities of our central nervous system. However, the implosion of the media is less obvious.”