Abstract This paper discusses how visual agnosia is a disorder where people can see objects, but are unable to recognize them. It looks at how agnosia it not a disease, but a disorder that arises as the result of neurological conditions such as strokes, dementia, or developmental disorders. It also examines how, because agnosia has several different causes, successful treatment relies upon correct diagnosis and treatment of the underlying disorder.
From the Paper ""The way in which messages are relayed from the eyes to the brain is not as straightforward as one might think." (Humphreys and Riddoch, 8). The visual pathway itself is complex. For example, objects recognized with one eye are perceived on the opposite side of the brain. However, visual agnosia is not associated with a problem in the actual visual pathway. Instead, agnosia is believed to reflect a problem in the later stages of sensory processing, "beyond the level of basic sensory mechanisms such as vision and acuity." (Rosello). Furthermore, visual agnosia is not always technically a perception problem; the patients can typically perceive and describe the physical details of a visual stimuli, but are unable to match that description to something held in memory. "
Abstract The paper introduces and defines Agnosia as a rare perceptual disorder of the brain whereby the person is unable to recognize and identify objects or persons whose characteristics are known to him. The paper shows several different types of Agnosia and explains the treatment offered to sufferers of the disorder. Finally, it explains the theory behind the treatment by a specialist in the field, Stephen Kosslyn, who conducted experiments and tests on sufferers.
From the Paper "He conducted experiments that showed how images act as functional representations with real-life spatial characteristics. His experiments indicated that it takes time for images to represent metric distance and that this property affects real-time processing of images. Using a test whereby the experiment subjects imagined to the point of overflow, the result showed that images also have spatial aspects. The same result pointed to the high correlation between the size of the visualized or imagined object and the distance. Moreover, it revealed that it took the experiment subjects longer time to visualize the properties of subjectively smaller images."
Tags: temporo-parieto-occipital, point, apperceptive, pictorialism
Abstract This paper explains the development, signs, symptoms and treatment of retinitis pigmentosa, agnosia and cerebral aneurysms. The author points out how these neurological disorders adversely affect the ability of the patient to handle everyday life situations. The paper concludes that having to endure any neurological disease adversely affects the patient's mental, emotional and social status as adults.
From the Paper "Many cerebral aneurysms can be caused by a type of trauma to the brain such a blunt impact from an automobile accident or a fall, an infection somewhere in the body or high cholesterol (atherosclerosis) which causes the arterial walls to harden. This disease can also occur due to any developmental disorder or birth defects, which occur more often in women than men. However, there are symptoms to look for when suspecting a cerebral aneurysm is present which include, seeing spots, dizziness, nausea, vomiting, black-outs, neck pain and headache."
Abstract The paper describes the condition of a soldier, Zasetsky, who suffered brain damage as a result of a bullet. The writer explains the type of memories Zasetsky is able to recall, his moods and his understanding. The paper discusses Zasetsky's ability to write, but not understand what he has written. In conclusion, the writer shows us how Luria's book has been of value to neurologists, and also to educators of individuals with traumatic brain injuries. Luria's book sheds light on the complexity and ability of the brain to do amazing things, despite traumatic injury.
From the Paper "At first he could not perceive a thing then, when he could, fragments didn't form complete objects. He had to guess what assembled fragments meant. Also, the right side of his visual field was "an even gray vacuum". After brain injury, there is usually a period of recovery, but what is not recovered within the first year or so is usually lost for good, apart from very small improvements.
"His sense of his body had changed. He experienced fragmentation of his body and certain body parts would feel large or small. For example, "...my head is the size of a table". Also, he forgot where body parts were and had to 'hunt' for them. He adjusted to these body problems but other disturbances persisted. Examples of 'spatial disturbances' was not knowing which hand to extend to shake hands and getting lost when going for a walk. When he left hospital and returned home he did not recognize his hometown. Indeed, "space 'made no sense to him'" and so it lacked stability. Spatial agnosia. To the extent that he had trouble organizing movements in space, he would also have had apraxia. With Zasetsky you are really sampling the A-Z of neuropsychological disorder."
Abstract This paper takes an in-depth look at Alzheimer's disease, a degenerative brain disorder that was first identified in 1906 by Alois Alzheimer. This disease represents the single most prevalent form of brain disorders and is also the leading cause of dementia, affecting approximately 4.5 million people in the Untied States. The paper provides a brief overview of the disease, the symptoms, the diagnostic procedures and the treatment methods in order for us to gain a better understanding of this degenerative brain disorder.
Outline:
Introduction
Alzheimer's Disease
Early and Late onset Alzheimer's Disease
Symptoms of the Disease
Memory Loss and Language Disorder
Depression
Dyspraxia and Agnosia Diagnosis
Tests for Cognitive Impairment
Positron Emission Topography
Major Causes of Alzheimer's Disease
Amyloid Plaques
NeuroFibrillary Tangles
Metal ions
Treatment Methods
Restoring Cholinergic Transmission
Anti-inflammatory Drugs
Conclusion
From the Paper "Considerable reduction in cholinergic transmission is one of the primary causes for the loss of memory and other associated symptoms of Alzheimer's disease and other kinds of dementia. Hence pharmacological treatment for AD mainly revolves around rectifying this circulatory deficit within the brain. Compounds designed to enhance cholinergic transmission constitute an important part of the treatment plan. Acetylcholine the neurotransmitter of the brain is considerably broken down in-patients suffering from AD and other dementias. The underlying mechanism of the neurotransmitter can be simplified as follows. An electrical impulse generated passes along the nerve and when it reaches the end it triggers the release of chemical messengers known as neurotransmitters, which in turn diffuse along the synaptic cleft and react with the specific receptor sites on the organ. Activation at the receptor junction initiates a series of chemical reactions resulting in a specific biological response. "
