The cause of the brain cells dying and the deterioration of the connectors is not fully known. Vascular dementia is a form of dementia caused by damage to the brain through deprivation of oxygenated blood. Causes are preventable and include high blood pressure, heart problems, diabetes and high cholesterol. Rarer forms of dementia are Creutzfeldt-Jakob disease (CJD) and Biswanger’s disease. 1.2 Types of memory impairment Whilst long term memory loss is experienced, short term memory loss can cause more problems, although it is not the same in every case.
With any severe injury, there is also usually a short period before the injury and events that occurred prior to the injury for which memory is lost which are often referred to as the retrograde Amnesia. Retrograde Amnesia in particular present interesting problems for any theory of the cerebral mechanism of memory, functioning normally, registration, retention and often recall of experiences all having actually occurred during a period sub sequently covered by a complete amnesia. In Anterograde amnesia patients often will loss memories of experiences that happen after the injury. These amnesias are interesting, because of their variable form and content and also because their time of onset can usually be accurately gauged and their duration measured. In assessing traumatic amnesia, it is usual to measure the post-traumatic amnesia as a period between the injury and the subsequent resumption of normal continuous memory.
Damage to the frontal lobe is typically associated with Semantic Dementia. Semantic Dementia implies a cognitive deficit affecting fundamental aspects of language, memory and object recognition,
Other less common causes of dementia may include depression, head injuries, alcohol misuse, brain tumours, infections of the brain such as HIV, Strokes, or lack of Vitamin B in the diet. These causes of dementia can be treatable or non progressive or in some cases reversible such as vitamin deficiencies or thyroid problems. Rarer causes of dementia include Huntington’s disease, or progressive supranuclear palsy. 1.2 The different types of memory impairments commonly experienced by individuals with dementia include thought impairment such as storing and retrieving memory problems, calculation, spelling, planning and organising. Many people can also have difficulty with day to day tasks.
. Disruption of this blood supply usually leads to a wide range of deficits, knocking out neighbouring regions that often have different functions16. On the other hand, owing to the redundancy of the human brain, small lesions that only partially damage a module might not lead to any obvious behavioural
Physiology is the way the organism functions through internal and biological living mechanisms. Amnesia can be defined as the inability to learn new or recall old information. There is an interaction between biological and cognitive factors in amnesia. The Loss of memory may be as a result of brain injury or deterioration, shock, fatigue, senility, drug use, alcoholism, anesthesia, illness, or neurotic reaction. Amnesia may be anterograde (in which events following the causative trauma or disease are forgotten) or retrograde (in which events preceding the trauma or disease are forgotten).
George Miller (1956) concluded that the span of immediate memory is 5-9 items. He also found that people can recall 5 words just as well as they can recall 5 letters, this is because if you chunk things together they are easier to remember. However Miller's study lacked ecological validity and contained several extraneous variables such as the effects of reading aloud, pronunciation time and individual difference – some people read faster than others. STM and LTM differ in terms of encoding, evidence of this is Baddely's study (1966) he tested the effects of acoustic and semantic similarity in short and long term memory. He gave participants two lists with similar or dissimilar acoustic and semantic words.
Short-term memory loss, disorientation and loss of concentration are common symptoms. There are other less common types of dementia such as Lewy Body dementia and Frontol Temporal dementias (including Picks Disease) which affect the parts of the brain which control social behaviour. Whatever type of dementia the person has, it eventually affects their ability
They include - Emotional stress Strenuous physical exertion Transient ischemic attack, a "mini-stroke." Basilar artery migraine, f) Wernike-Korsakoff's psychosis – This amnesia is a progressive disorder caused by extended alcohol abuse. It is usually accompanied by neurological dysfunctions such as loss of co-ordination during movement or a feeling of numbness in the fingers and
People with delirium suffer from hallucinations and delutions which means they hear see or think things that are not real, their thinking and reasoning are affected significantly and severe confusion is often present as in most cases of dementia. Age related memory impairment can cause forgetfulness again similar to dementia. The most common causes of different types of dementia are as follows. Alzheimer's disease: Alzheimer's disease is caused by parts of the brain wasting away, which damages the structure of the brain and how it works.It is not known exactly what causes this process to begin, but people with Alzheimer's disease have been found to have abnormal amounts of protein and fibres in the brain.These reduce the effectiveness of healthy neurons, gradually destroying them.Over time, this damage spreads to other areas of the brain such as the grey matter and the hippocampus. Risk factors