Herbal Health – information on herbal medicine

The more we studied the profiles of memory impairment in various types of patients, the more important the distinction between generic memory and specific memory appeared to be. Memory provides the content for our mental lives, but not all memories are equal. Some are much more resistant to the effects of any assault on the brain than others. The distinction between specific memories and generic memories is so important because it shapes our understanding of the fates of different kinds of knowledge in brain disease and brain decay. Knowledge that Paris is the capital of France is an example of singular memory. There is only one Paris and one France, so this knowledge refers to a single entity. By contrast, knowledge that tomatoes are usually red is an example of generic memory, since there are millions of tomatoes on the face of the earth and this knowledge applies to all of them.As a rule, generic memories are accessed much more frequently than specific memories. How often does an average American invoke the knowledge that Paris is the capital of France? A few times a month at most, whenever Paris is mentioned in the news, or when you plan your once-in-a-lifetime dream vacation. But you invoke the knowledge that tomatoes are usually red every time you walk down the supermarkets aisles or stick your fork into your daily lunch salad. Consequently, generic memories are much more robust than singular memories. Because of their high frequency of use, generic memories become committed to long-term storage more rapidly. As a result, they gain independence from the subcortical brain structures known to be particularly vulnerable in Alzheimer’s disease and other dementias. The relative invulnerability of generic memory becomes quite obvious if we consider two essential attributes of our mental life, which tend not to fade with age: language and higher-order perception. Although we tend not to think about these abilities as “memory,” they are. In order to use language effectively, we need to “remember” which word refers to which thing, since the relationship is in most instances a matter of arbitrary convention and cannot be deduced logically. A language in which the word “chair” means table and the word “table” means chair would be every bit as effective as the language we use. And needless to say, the memory of the meaning of words, which is the basis of our linguistic competence, is generic memory, since any given word refers to a whole class of similar objects. A white Art Deco table, and a black-lacquered Chinese table, and a decrepit, rickety table in your neighborhood coffee shop are equal members of the same category and you refer to them with the same word, “table.” Likewise, our ability to recognize objects for what they are is also based on memory. Haven’t you ever marveled at your own ability to come into contact with something you have never seen or heard before, and to instantly know what it is? You see an elaborately designed antique car on the street and you know that it is a car, despite the fact that you had never seen the likes of it. You hear a sound coming from outside, and you know that this is a dog barking, even though you had never heard a bark of this particular kind. To possess this ability, you must have a generic memory stored somewhere in your brain that captures the common characteristics of a whole class of things. You must have a previously formed pattern. Then, when you encounter an object containing enough of such shared characteristics, the generic memory will be evoked, and this is what object recognition is all about.Thus, both language and higher perception are based on generic memories. Certain kinds of brain diseases may wipe these memories out, causing the patient to lose the use of words and the ability to recognize common objects. You may recall that in psychological and medical parlance these two types of symptoms are known as “anomia” and “associative agnosia.” Such a breakdown of generic memories may be affected by stroke, traumatic brain injury, dementia, or some other brain disease. But the neocortex must take a direct hit for language or higher-order perception to suffer. Damage to the subcortical machinery alone will not affect them, since, as we now know, generic memories do not depend on this machinery. What’s particularly important is that language and higher-order perception are also resistant to the effects of normal aging. This is so, at least in part, because they are independent of subcortical structures. An important point follows. Since singular memories depend on both the neocortical and subcortical brain structures, damage to either of the two, or to the connecting pathways, will cause their decay. This is a case of neurological double jeopardy. By contrast, generic memories depend on only the neocortex. This means that it takes a much more targeted kind of brain damage to affect them. While not totally protected from decay (nothing is), generic memories have fewer neurological Achilless heels, fewer points of neural vulnerability. This is why generic memories tend to not decay with age and may even be resistant to the effects of dementia up to a point.The knowledge that frequent exposure to a particular kind of mental task speeds up the formation of a robust, long-term representation of the task and everything associated with it (including previous successful solutions) goes a long way toward understanding why certain kinds of memory are resistant to the effects of brain decay. But the formation of structural neocortical representation is not the only safeguard the brain develops to protect valuable information against the vagaries of neurological deterioration or illness. Other protection mechanisms are also at work. The discovery of such mechanisms was made possible by state-of-the-art methods of functional neuroimaging. These methods, which include fMRI (functional magnetic resonance imaging), PET (position emission tomography), SPECT (single photon emission computerized tomography), MEG (magnetoencephalography), and others, made it possible for the first time in the history of science to observe the landscapes of physiological activation in a working brain of a living person, as the person is engaged in various mental activities. The introduction of these methods has changed the face of neuropsychology and cognitive neuroscience in a way not dissimilar to the one in which the invention of the telescope advanced astronomy. No field of inquiry can thrive on concepts alone, and the introduction of powerful new technologies (themselves products of novel ideas in other fields) usually plays a decisive role in scientific progress.The application of these methods has led to the discovery of two additional protection mechanisms guarding frequently used knowledge represented in the neocortex. They are the mechanisms of pattern expansion and forging effortless experts. These two mechanisms work in concert.In pattern expansion, with practice, experience, and repeated use the brain areas allocated to a particular motor, perceptual, and perhaps also cognitive skill expand and take over the adjacent parts of the cortical space. This was demonstrated in a variety of skill-learning experiments in the monkey by Michael Merzenich and his colleagues at the University of California, San Francisco. Even more to the point, similar effects have been demonstrated in humans. Alvaro Pascual-Leone has shown that in the blind, the cortical representation of the finger used for reading Braille is larger than the cortical representation of the same fingers in Braille-naive seeing individuals. Likewise, the cortical representation of left-hand fingers is larger in string musicians than in other people. Such expansion makes the patterns more resistant to decay and to the effects of brain disease. To understand how this works, consider a simple Swiss-cheese model with a certain number of holes covering an area. If the number and size of the holes is kept constant, then the larger the total cheese-slice area, the larger the area spared by the holes will be.While it may sound both irreverent and simplistic, the Swiss-cheese analogy is not that far off. In a number of age-related brain disorders, the brain is affected by tiny, discrete lesions, which destroy nerve cells and disrupt the communication between them. In Alzheimer’s disease, the lesions are the infamous microscopic tangles and plaques, the debris of decaying and dying nerve tissue. In Lewy body disease, another primary degenerative disease, less prevalent and less well-known to the general public but every bit as malignant, the lesions are the microscopic Lewy bodies. In a different type of dementia, the so-called multiinfarct or small vessel disease, caused by a widespread disorder of brain vasculature, the lesions are tiny infarctions distributed throughout the brain. Whatever the etiology and pathogenesis of these lesions, they damage the brain tissue the way randomly thrown darts damage a bull’s eye. But the greater the overall area of a bull’s eye, the vaster will be its spared part—if not in proportionate then at least in absolute terms, which is probably what matters most for the preservation of a cognitive skill.*27\302\2*

Your options for medical care will depend on where you live. The kind of care specific to HIV infection is likely to be better in a big city: most big cities offer many options for treatment of HIV infection. Smaller cities and rural areas are likely to offer fewer options, and the physicians in these areas are likely to be less familiar with HIV infection. This is because most of the people who became infected in the early stages of this epidemic lived primarily in large cities like New York, San Francisco, Los Angeles, Miami, and Washington, D.C.; disproportionately fewer people living in smaller cities and rural areas were infected. As a result, physicians who trained or who practice in small cities or rural areas often lack experience in treating HIV infection.     As a consequence, when people with HIV infection who live in small cities and rural areas want medical treatment or periodic consultation about medical treatment, they often travel to the nearest physician or clinic specializing in HIV infection.     The options for medical care may also be substantially fewer for people who belong to HMOs, for people receiving Medicaid, and for people who have limited financial resources and no health insurance. HMOs and city health clinics offer medical services that vary in quality, some very good and some not so good. Some HMOs do not allow patients to see physicians other than those physicians who participate in the HMO, or do so only on a case-by-case basis. People enrolled in those HMOs therefore have no choice in what specialists they see. HMOs can also limit the hospitals people may be admitted to.     The process of selecting among medical options begins with finding out what your finances allow. This disease is expensive, and HMOs, insurance plans, and Medicaid will each pay for some things and not for others. In addition, HMOs, insurance plans, and Medicaid all differ in what they will and will not pay for. Many insurance plans especially restrict the outpatient services they cover. Medicaid covers a broad range of services but reimburses physicians at so low a rate that most physicians refuse to accept patients paying through Medicaid. Many employers offer a choice between joining an HMO or being reimbursed by the insurance company, and you may be able to switch back and forth as your needs dictate. In any case, you need to know your options. You can begin by finding out what your HMO, insurance company, or government medical assistance will allow, and then discussing these issues candidly with your physician or with a social worker.

When your child has had a second or third seizure, family and friends need to be informed. Your child has probably been started on medication and could experience side effects or even temporary changes in personality from the medication. The likelihood of your child having a further seizure is now high enough that family and friends should be informed. They should know what these “frightening episodes” look like and what they should do if another occurs. They should know about the various false myths about epilepsy. Most of the time your child will be normal. Make sure epilepsy is not blown out of proportion. Don’t let your friends and relatives dwell on it. If they understand, perhaps they can avoid the overprotection and restrictions that deprive your child of normal experiences.*180\208\8*