question: How come people with Alzheimer's disease do not forget how to speak their native language?
comment: Some of them do... long term memory and short term memory are very different things. Learning to speak language is something we encode in ourselves at a young age. Even then, you are incorrect here as people often do forget how to put words together in the sentence they are attempting properly. People with this disease literally forget key things about themselves. Nothing is off limits.
passages: Section::::Bilingualism and the onset of dementia.:Cognitive reserve and Alzheimer's disease.
  
  Like the protection bilingualism appears to provide against general cognitive deterioration, it has been hypothesized that bilingualism may also slow the onset of symptoms specifically brought about by Alzheimer's Disease (AD). It is thought that bilingualism might be a factor contributing to cognitive reserve, which in turn, may help delay the onset of Alzheimer's symptoms.
   Further research supports the above hypothesis, and extends it claiming that bilingualism can postpone the onset of the symptoms of AD by as much as 4–5 years. Bialystok, Craik, and Freedman collected data from bilingual and monolingual patients diagnosed with probable Alzheimer's disease regarding, most importantly, age of onset of cognitive impairment and language history and abilities. A 4.3 year delay in diagnosis and a 5.1 year delay in the reported onset of symptoms was found for the bilinguals in comparison to the monolinguals. Not only do these data support the notion of bilingualism contributing to cognitive reserve, thereby compensating for higher levels of brain atrophy, but also that bilingualism might even postpone the onset of AD symptoms by a dramatic 4–5 years.
   Language problems are mainly characterised by a shrinking vocabulary and decreased word fluency, leading to a general impoverishment of oral and written language. In this stage, the person with Alzheimer's is usually capable of communicating basic ideas adequately. While performing fine motor tasks such as writing, drawing or dressing, certain movement coordination and planning difficulties (apraxia) may be present, but they are commonly unnoticed. As the disease progresses, people with AD can often continue to perform many tasks independently, but may need assistance or supervision with the most cognitively demanding activities.
  
  Section::::Signs and symptoms.:Moderate.
   Section::::Bilingualism and the onset of dementia.
  
  The natural process of aging has a deteriorating effect on the brain, and commonly leads to detrimental conditions such as dementia or more specifically, Alzheimer's disease. With the bilingual advantage that appears to persist throughout a person's lifespan, it is plausible that symptoms of these conditions could be offset or further delayed by the lifelong advantages brought about by bilingualism.
  
  Section::::Bilingualism and the onset of dementia.:White matter and brain reserve.
   In people with AD, the increasing impairment of learning and memory eventually leads to a definitive diagnosis. In a small percentage, difficulties with language, executive functions, perception (agnosia), or execution of movements (apraxia) are more prominent than memory problems. AD does not affect all memory capacities equally. Older memories of the person's life (episodic memory), facts learned (semantic memory), and implicit memory (the memory of the body on how to do things, such as using a fork to eat or how to drink from a glass) are affected to a lesser degree than new facts or memories.
   As people grow older, it has been shown that white matter integrity in the brain generally decreases as the natural process of aging takes its course, resulting in a decline of cognitive functioning and control. Because previous work has demonstrated a greater cognitive ability in older bilingual adults, however, it is thought that lifelong bilingualism may mitigate this cognitive decline, resulting in a higher level of white matter integrity and connectivity in these individuals, and therefore greater cognitive ability over that of their monolingual counterparts.
   People who engage in intellectual activities such as reading, playing board games, completing crossword puzzles, playing musical instruments, or regular social interaction show a reduced risk for Alzheimer's disease. This is compatible with the cognitive reserve theory, which states that some life experiences result in more efficient neural functioning providing the individual a cognitive reserve that delays the onset of dementia manifestations. Education delays the onset of AD syndrome without changing the duration of the disease. Learning a second language even later in life seems to delay getting Alzheimer disease.
   Ten years later, Paul Broca examined two patients exhibiting impaired speech due to frontal lobe injuries. Broca’s first patient lacked productive speech. He saw this as an opportunity to address language localization. It wasn’t until Leborgne, formally known as "tan", died when Broca confirmed the frontal lobe lesion from an autopsy. The second patient had similar speech impairments, supporting his findings on language localization. The results of both cases became a vital verification of the relationship between speech and the left cerebral hemisphere. The affected areas are known today as Broca’s area and Broca’s Aphasia.
   In another recent study in Canada, it has been shown that monolinguals were worse at the onset of senility than bilinguals. In the study, it seems that being bilingual is associated with a delay of dementia by four years as compared to monolinguals. Bialystok's most recent work also shows that lifelong bilingualism can delay symptoms of dementia.
   Compared to other forms of primary progressive aphasia, the logopenic variant has been found to be associated with cognitive and behavioral characteristics. Studies have shown that patients with the logopenic variant perform significantly worse on tests of calculation than other primary progressive aphasia patients. Several logopenic variant patients, especially those with Alzheimer’s disease pathology, have also been found to perform poorly on memory tasks.
   Whether or not PPA and other aphasias are the only source of cognitive impairment in a patient is often difficult to assess because: 1) as with other neurologically degenerative diseases, such as Alzheimer's disease, there are currently no reliable non-invasive diagnostic tests for aphasias, and thus neuropsychological assessments are the only tool physicians have for diagnosing patients; and 2) aphasias often affect other, non-language portions of these neuropsychological tests, such as those specific for memory.
  
  Section::::Diagnosis.:Classification.
   Caretakers of adults with Alzheimer's are often told to speak to their patients more slowly, although slow speech has not been proven to improve comprehension in patients with Alzheimer's.
  
  Section::::Use of elderspeak.:Non-medical.
   To test the protection of bilingualism against Alzheimer's disease (AD), Bialystok et al. (2007) examined the hospital records of monolingual and bilingual patients who had been diagnosed with various types of dementia. After controlling for various cognitive and other factors, the researchers found that bilinguals experienced the onset of symptoms and were diagnosed approximately 3–4 years later on average than monolinguals. This was replicated with patients all diagnosed with AD. It is important to stress, however, that the studies did not show that bilingualism directly prevents one from having AD, but rather enables functional cognition for a longer period of time; it delays the onset of symptoms for those with the disease. This was confirmed by the finding that when monolingual and bilingual Alzheimer's patients' brains were scanned, bilinguals actually had more pathology (signs of disease) and damage than the monolingual patients. This suggests that active use of the two languages protects against the symptoms of the disease; areas of the brain that enable cognitive control may have benefited from the bilingual experience and so improve cognitive function in older age. 
   Bialystok, Craik, Fischer, Ware, and Schweizer analyzed and measured brain atrophy in both monolingual and bilingual patients diagnosed with AD using computed tomography (CT) scans with the logic that bilingual patients, when matched with monolingual patients on level of disease severity, should exhibit more atrophy in areas typically used to discriminate between AD patients and healthy ones, as their enhanced cognitive reserve brought about by bilingualism would allow a higher level of functioning than would usually be associated with that level of disease. Results supported this notion and found that the bilingual patients with AD did, in fact, show a greater level of brain atrophy in relevant areas. Even with this increased level of atrophy, however, the bilingual group still performed at the same cognitive level as their monolingual counterparts. These results support the hypothesis maintaining that bilingualism works as a contributor to cognitive reserve and acts as a modifier to behavioral expression that underlies brain atrophy associated with Alzheimer's disease.
   Several severe injuries or diseases can cause IA in a wide range of patients. Alzheimer's patients are the largest cohort groups that express IA. Other groups that are often seen with this dysfunction are stroke victims, traumatic brain injuries, and dementia. The damage is almost always found in the dominant hemisphere (i.e. usually the left hemisphere) of the patient.
  
  Section::::Pathophysiology.
   In humans, the posterior hippocampi of licensed London taxi drivers was famously found to be larger than that of matched controls, while the anterior hippocampi were smaller. This study shows that people choosing taxi driving as a career (one which has as a barrier to entry - the ability to memorize London's streets - described as "the world's most demanding test (of street knowledge)") have larger hippocampi, but does not demonstrate change in volume as a result of driving. Similarly, while acquiring a second language requires extensive and sustained cognitive activity, it does not appear to reduce dementia risk compared to those who have not learned another language. although lifelong bilingualism is associated with delayed onset of Alzheimer's disease.
   BULLET::::- Agrammatism (using the wrong tense or word order)
  
  As the disease develops, speech quantity decreases and many patients become mute.
  
  Cognitive domains other than language are rarely affected early on. However, as the disease progresses, other domains can be affected. Problems with writing, reading, and speech comprehension can occur, as can behavioural features similar to frontotemporal dementia.
  
  Section::::Classification.
   Since people suffering from phonagnosia do not suffer from aphasia, it is suggested that the structures of linguistic comprehension are functionally separate from those of the perception of the identity of the speaker who produced it.
   Conduction aphasia is another speech disorder that is similar to, but not the same as, apraxia of speech. Although patients who suffer from conduction aphasia have full comprehension of speech, as do AOS sufferers, there are differences between the two disorders. Patients with conduction aphasia are typically able to speak fluently, but they do not have the ability to repeat what they hear.
   During the final stages, the patient is completely dependent upon caregivers. Language is reduced to simple phrases or even single words, eventually leading to complete loss of speech. Despite the loss of verbal language abilities, people can often understand and return emotional signals. Although aggressiveness can still be present, extreme apathy and exhaustion are much more common symptoms. People with Alzheimer's disease will ultimately not be able to perform even the simplest tasks independently; muscle mass and mobility deteriorates to the point where they are bedridden and unable to feed themselves. The cause of death is usually an external factor, such as infection of pressure ulcers or pneumonia, not the disease itself.
   The effects of Alzheimer's disease are seen in the episodic part of explicit memory. This can lead to problems with communication. A study was conducted where Alzheimer's patients were asked to name a variety of objects from different periods. The results shown that their ability to name the object depended on frequency of use of the item and when the item was first acquired. This effect on semantic memory also has an effect on music and tones. Alzheimer's patients have difficulty distinguishing between different melodies they have never heard before. People with Alzheimer's also have issues with picturing future events. This is due to a deficit in episodic future thinking.
   The inability to speak stems from a deeper mental inability that causes alogic patients to have difficulty grasping the right words mentally, as well as formulating their thoughts. A study investigating alogiacs and their results on the category fluency task showed that people with schizophrenia who exhibit alogia display a more disorganized semantic memory than controls. While both groups produced the same number of words, the words produced by people with schizophrenia were much more disorderly and the results of cluster analysis revealed bizarre coherence in the alogiac group.
  
  Section::::Causes.
   Many language impairments, including paraphasic errors, are reduced in number through spontaneous recovery of neurological function; this occurs most often with stroke patients within the first three months of recovery. Lesions associated with ischemic strokes have a shorter spontaneous recovery time, within the first two weeks, and lesions associated with hemorrhagic strokes, on the other hand have a longer period for spontaneous recovery, four to eight weeks. Whether spontaneous recovery occurs or not, treatment must begin immediately after the stroke. A traditional approach requires treatment beginning at the level of breakdown - in the case of paraphasia, at the level of the phoneme. There are commercially available workbooks that provide various activities such as letter, word-picture, or word-word matching, and sentence completion, among other things. The difficulty of these activities varies with the level of treatment. However, these treatments have not been proven to be clinically productive. Functional magnetic resonance imaging is the most widely used technique to study treatment-induced recovery, looking at activation of particular areas of the brain. There are many different ways to process fMRI scans, beginning with the pre-scanning process. Data must be normalized. There is also no consensus on whether or not single subject scans are more helpful than group scans to determine a general pattern of treatment. However, fMRI scans have a few disadvantages.
   Patients with Alzheimer's disease (AD), the most common form of dementia, have been studied extensively as far as priming goes. Results are conflicting in some cases, but overall, AD patients show "decreased" priming effects on word-stem completion and free association tasks, while retaining normal performance on lexical decision tasks. These results suggest that AD patients are impaired in any sort of priming task that requires semantic processing of the stimuli, while priming tasks that require visuoperceptual interpretation of stimuli are unaffected by Alzheimers.
  
  Section::::Effects of brain injuries.:Focal cortical lesions.
   Alogia can be brought on by frontostriatal dysfunction which causes degradation of the semantic store, the center located in the temporal lobe that processes meaning in language. A subgroup of chronic schizophrenia patients in a word generation experiment generated fewer words than the unaffected subjects and had limited lexicons, evidence of the weakening of the semantic store. Another study found that when given the task of naming items in a category, schizophrenia patients displayed a great struggle but improved significantly when experimenters employed a second stimulus to guide behavior unconsciously. This conclusion was similar to results produced from patients with Huntington's and Parkinson's disease, ailments which also involve frontostriatal dysfunction.
  
presuppositions: People with Alzheimer's disease don't lose the ability to speak their native languge. People with Alzheimer's disease don't forget how to speak their native language.
corrections: Some people with Alzheimer's disease forget how to speak languages. People with Alzheimer's disease can forget how to speak their native language.
raw_presuppositions: People with Alzheimer's disease don't lose the ability to speak their native languge. People with Alzheimer's disease don't forget how to speak their native language.
raw_corrections: Some people with Alzheimer's disease forget how to speak languages. People with Alzheimer's disease can forget how to speak their native language.