Users Guide to the Brain by Ratey

8/8/2019 Users Guide to the Brain by Ratey

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A Users Guide To The Brain

John Ratey M.D.

ISBN 0-679-45309-1

A collection of fascinating facts gleaned from this book.

Page 169

Recent research has overturned the old neruologic dogma that adult brains cannot renewthemselves. It used to be thought that neural stem cells-which divide to produce nerve

cells in an embryonic brain-shut down in adulthood. But Brent Reynolds and Sam Weiss

at Neurospheres, a Canadian biotechnology company, have shown that stem cells are still

alive and well in adults. They just need to be switched on again. This prompting is donewith growth factors-molecules that stimulate tissue growth that turn genes on and off and

then maintain mature organs. Reynolds has shown in controlled experiments that stem

cells treated with growth factors can be persuaded to produce new nerve cells.

Page 175

Whats even more fascinating is that motor control of movement related to emotion is notin the same location as the control for a voluntary motion of the same kind. For example,

when a stroke destroys the motor cortex of the brains left hemisphere, the patient

experiences paralysis on the right side of the face. When asked to smile the patient

cannot move the right side of his mouth. However, when the same patient is told a jokeand laughs spontaneously, the smile is normal; both sides of the mouth move as they

should. The cortex cannot exercise its usual control of the muscles, but the muscles still

respond to the more automatic and implicitly learned responses that are located on thefirst floor-the basal ganglia.

Page 183The study of false memory was pioneered by Elizabeth Loftus at the University of

Washington in Seattle in the 1970s. She walked the adult children through a list of the

real incidents and occasionally slipped in a fake one.When asked to check off on a list the events that had actually occurred in their childhood,

about one quarter of them indicated that they had more confidence that the event they had

imagined had actually happened to them. See the book for the actual quotation as it wasfairly long. H.B.

Page 188

Sleep, specifically the sleep associated with dreaming, is important to human memory. InIsrael, researchers Avi Karni and Dov Sagi at the Weizmann Institute found that

interrupting REM sleep sixty times in a night completely blocked learning, but

interrupting non-REM sleep just as often did not. These findings and others suggest thatREM sleep is crucial for organizing pieces and associations between them needed for

forming lasting memories.

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Page 205

Creative and artistic individuals do indeed possess higher levels of interhemespheric

communication. The creative meanderings and patternings of the right hemisphere arenot enough for creativity; they must be joined with action or language (motor functions)

coordinated by the left hemisphere to be demonstrated to the world. (the opposite is true

for lefties.) A beautiful sonnet or painting in someones head must be expressed throughan understandable medium, which requires fine-motor movements. Other studies show

that creative people also have a higher degree of cortical arousal.

Page 206

A raft of studies that hit the popular media in 1996 showed that training in the arts, which

is in large part rehearsal of movements, extended to good learning in other areas.

The famous example of this phenomenon is Albert Einstein, who played the violin

regularly. At times he would suddenly stop playing, jump up and scribble down an idea

or part of an equation. People who hum or whistle a tune while they are contemplating

something- or walk the Stairmaster exercise machine, as I do are using motor programsin the brain to help them wander along in thought in search of neuronal connections. One

reason motor function and memory are so closely linked, as noted in the previous chapter,is that they are both coordinated by the frontal lobe, home of the brains executive

function.

Page 325Autism

APD is a complex failure of the social brain. Autism on the other hand, is a

developmental disorder that strikes at the heart of what makes us human: our ability tolove, laugh, and encounter others. People with autism have a range of symptoms that can

include deficits in IQ, delayed or nonexistent language, self-injurious behavior, and

repetitive, stereotyped movements. Some autistic people can have amazing talents aswell, such as an almost photographic drawing ability.

Leo Kanner of the John Hopkins Childrens Psychiatric Clinic described and named

autism in 1943. He listed four traits: a preference for aloneness, an insistence onsameness, a liking for elaborate routines and some abilities that are remarkable compared

with those of the average person. Autistic people can be very upset at the slightest

change in routine.

Today autism is the diagnosis when a person has impaired social skills, impaired

language, and significantly restricted interests. There are many ways that these

symptoms and their subsets can be expressed. Whatever the individual mix, however, allautistic people show a profound deficit in social abilities.

However, more recent research has shown that autism does have a genetic basis.Identical twins are more likely to both be autistic than fraternal twins. Autism is 50 to

100 times more likely to occur twice in the same family than would be expected by

chance. Structural differences in the brains of autistic individuals-such as a smaller

cerebellar vermis or uncommon cell structures in other parts of the cerebellum,

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hippocampus, and amygdale-have been widely reported in postmortems, and the deficits

that autistic people show in tests of planning, initiative, and imagination are similar to

those suffered by people with frontal-lobe damage.

Page 326-327

Autistic children cannot understand pretense and do not pretend when they are playing.It is unclear why this is so. Perhaps they do not have an inborn mechanism that allows

them to delay long enough in their thinking process to shift to a different level of

meaning, or have difficulty shifting from one line of thinking to another. They are boundby where they are. They are unable to put themselves in another persons place. It is as

if the ability to manipulate ideas and see them from more than one perspective as well as

a powerful integrating force to seek meaning are missing.

Other theories link autism to cerebellar damage, which would interfere with smooth

coordination of shifts in attention. Most recently, another group of theorists, Lynn

Waterhouse and colleagues at Trenton State College, identified four neurofunctional

deficits in autism. The first is canalesthesia, a problem with the hippocampus, thememory center of the brain. In this dysfunction the neurons in the hippocampus have too

great a cell-packing density, which results in abnormal fragmentation of both currentevents and long-term memories. The second is a problem with the amygdale that disrupts

the ability to assign emotional significance to events as they happen. The third is

asociality, a problem with the oxytocin system that leads to less bonding and affiliative

behavior. The fourth is extended selective attention, a problem with the temporal andparietal lobes that causes over processing of primary representations, where the brain gets

stuck on some detail. Causal relationships between symptoms have not been established,

though, and the variety of symptoms in autism makes it difficult to find a single cause ofthis disorder.

Regardless of which theory prevails, all of them take into account that autism results

from deficits in several areas of the social brain. Some scientists think this could be theresult of damage to the developing embryos brain. Patricia Rodier of the University of

Rochester reported that in 33 percent of mothers, who before its use was banned in

pregnant women, had ingested thalidomide between days 24 and 27 of pregnancy, theirchildren developed autism, and that fetuses exposed at other times did not (thalidomide is

a tranquilizer that was used to help prolong pregnancy and was banned because it was

proved to cause birth defects). The period between days 24 and 27 of pregnancy is

exactly the time that the brain neurons are just starting to form.Other evidence supports injury in the first trimester, particularly to the brainstem, as the

cause of autism. Many autistic people have problems with eye movements, facial nerve

palsy, and hearing problems that are indicative of brainstem injury. All of this researchcan give us insight into how to help people with autism and how the social brain works in

everyday situations.

Page 364

Mental exercise strengthens and even renews neural connections, keeping the brain

flexible and resilient. For years scientists believed that the irreversible loss of neurons

was inevitable in old age. However, actual evidence indicates that there is not a great

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deal of loss. PET scans show that the frontal lobes of a twenty-five year old and a

seventy-five year old glow equally bright after the same memory test.

Decline in old age is caused primarily by the lack of mental exercise.New mental tasks increase neural connections and help the brain become more adaptive

to future events, whether these include coping with the death of a family member or

mastering a new computer language. You have the best chance of growing connectionsbetween your axons and dendrites by tackling activities that are unfamiliar to you.

You can indeed teach an old dog new tricks.

The lesson here is that we have the power to change our brains. The human brains

amazing plasticity enables it to continually rewire and learn, not just through academic

study but through experience, thought, action, and emotion. As with our muscles, we canstrengthen our neural pathways with exercise. Or we can let them wither. It is wise to

remember once again one of the brains most basic principles: Use it or lose it.

Page 366Memory changes due to advancing age are largely the result of lesser efficiency in

processing, not of some pathological breakdown in the brain. Aging is unavoidable;severe memory loss is not. Several factors may slow the onset of memory problems

encountered in Alzheimers disease and other forms of dementia. The intake of anti-

oxidants such as vitamin E and selegeline may help the brain fend off cellular attacks on

the neurons. The use of no steroidal anti-inflammatory drugs (NSAIDs) such as aspirinand ibuprofen may be helpful too, since inflammation is thought to be a cause of the

plaques and tangles found in the brains of Alzheimers patients. Corroboration comes

from a view of numerous epidemiological studies on people with arthritis; earlyindications are that those who have taken anti-inflammatory agents for years to reduce

the symptoms of arthritis have a decreased risk of Alzheimers. but researchers have

issued a strong warning against using these studies as a mandate to start downing aspirinor ibuprofen daily. None of the anti-inflammatory drugs was ever designed for long term

use, and there could be serious side effects such as damage to the stomach lining, internal

bleeding and interference with kidney function- conditions that could be much more lifethreatening than Alzheimers.

Page 369

Poor diet is common in people who suffer from depression and other mental disorders.Even minor nutritional deficiencies can be associated with changes in mood. Memory

loss, confusion, depression, and other mental disorders in the elderly, once attributed

simply to aging, can also be the consequences of a poor diet.One significant relationship is that food intake affects the formation and activity of

neurotransmitters. It is no coincidence that people turn to pasta, desserts, and other

carbohydrate-rich foods when they feel down in the dumps. Carbohydrates increasebrain concentrations of an amino acid called tryptophan, which is the building block for

the neurotransmitter serotonin. Consequently, increased tryptophan means a higher level

of serotonin in the brain, which in turn relieves depression, insomnia, and irritability by

promoting the feelings of calmness and serenity.

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Page 369 (continued lower down) and 370

In recent studies, rapidly lowered cholesterol levels have been associated with

depression, anxiety , panic disorder, violence, and suicide. When we go wild in alteringfood intake, in this case absurdly lowering cholesterol levels, we risk upsetting the

equilibrium we need.

Deficiencies in vitamins B1, B2, B6, and B12, niacin, folic acid and vitamin C are often

found in psychiatric patients and are thought to contribute to a cycle of depression, lack

of interest in food, progressive malnutrition, and increasing mental and emotionaldisorders. Vitamin deficiencies seldom occur singly and are almost always accompanied

by inadequate intake of other vitamins, protein, iron, and minerals.

Even small deficiencies in normal people can promote personality and mood changes,

insomnia, aggressiveness, and impaired reasoning and judgment. Clearly, a better dietrich in vitamins and minerals, with supplements if necessary, is the road to reversing

many ailments of the brain. This may sound as old as the ages, but a balanced diet is the

best brain medicine.

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Users Guide to the Brain by Ratey