Agnosia (Essay Sample)

Agnosia Student’s Name Institutional Affiliation Course Professor Date Agnosia Agnosia is a rare neurological illness that impacts people's ability to recognize objects, sounds, or places while utilizing one or more of their senses. While this disorder affects patients' auditory and tactile senses, the visual faculty is the most impacted element in the sensation and perception systems. Over the years, researchers have discovered two types of visual agnosia: associative and apperceptive agnosias. Associative agnosia refers to abnormalities in an individual's visual perception and discriminative processes, despite the lack of visual impairments. In contrast, apperceptive agnosia refers to an individual's decreased capacity to build a conscious representation of an object's structure. This defect is associated with disruption to primary perceptual processes, resulting in a diminished sensory system that interferes with normal visual functions. More importantly, the simple difference between associative agnosia patients and their apperceptive counterparts is that while the former can copy images in a sketch, the latter cannot. Nonetheless, the two types of agnosia involve a general impairment in object recognition among the affected population. Because of limited research on the prevalence of agnosia, analyzing and evaluating the few available resources is crucial to understanding the disease's prognosis and potential therapies. Apperceptive agnosia patients face significant visual challenges, including a reduced ability to distinguish shapes and objects. According to Haigh et al. (2018), an individual with apperceptive agnosia not only has significant difficulty with object identification but also struggles with other essential activities, including reproducing a target stimulus or correlating a target object with one of several possible items. Thus, these patients cannot reproduce or sketch visually depicted patterns or objects. Instead, they frequently compensate for their primary perceptual issues by relying on other sensations, such as touch, to aid in object identification. For instance, a patient may fail to recognize a bowl visually but may determine the object's color and identify it by touch depending on its shape or texture (Kumar & Wroten, 2022). Still, there can be varying levels of visual disability, with those mildly affected retaining their ability to detect and contrast the sizes of two bodies, separate a body from a background on which it has been presented, and differentiate two overlapping images. Apperceptive agnosia is a rare disorder that affects about one to three percent of the general public. It impacts men and women equally and is most typically encountered in adults due to brain injury. Most incidences are connected with severe brain traumas, stroke, tumors, or overexposure to harmful compounds such as carbon monoxide, which can impair neuron connections in critical visual regions. Studies show that people who have sustained brain injuries face high risks of developing visual complications, leading to loss of independence, spatial orientation, and the ability to engage effectively in social interactions (Heutink et al., 2018). Although brain injuries in patients are often not solely restricted to one region, the neuropathology of the condition shows a substantial level of homogeneity, with several cases primarily related to harm to the occipital cortex, the portion of the brain responsible for visual perception. In these circumstances, patients may first experience cognitive issues before developing evidence of agnosia following a recovery. Apperceptive agnosia has been related to bilateral abnormalities in the lateral region of the occipital lobe, which anoxic events from carbon monoxide or mercury poisoning may cause. A study by Milner & Cavina-Pratesi (2018) established that carbon monoxide poisoning causes significant bilateral lesions on the lateral occipital region, which diminishes patients’ ability to detect and differentiate patterns. In severe cases, the poisoning exposes patients with apperceptive agnosia to risks of death. Indeed, despite agnosia being a rare disorder, clinicians and patients face tremendous pressure to manage the illness. Across the literature, researchers explain apperceptive agnosia using three theories: sensory deficit model, peppery mask account, and grouping deficit account. The sensory impairment explanation, one of the earliest models, linked all the visual challenges patients have to deficits in sensory processing leading to distorted vision (Vecera & Gilds, 1998). While explaining specific characteristics of the apperceptive condition, this hypothesis does not address the distinction between apperceptive and associative agnosias. In contrast, Campion and colleagues' (1985) peppery mask approach offers explicit claims concerning the impairments of apperceptive agnosia. This viewpoint emphasizes that patients have several defects in the visual cortex that fill the field of vision with many (peppered) scotomas of varying sizes and spatial distribution (Vecera & Gilds, 1998). These scotomas disrupt sensation and perception by causing people to appear to be seeing through a peppery mask, which eventually impairs the visual sensory system. Moreover, the grouping deficit theory proposes that recognizing objects entails grouping various perceptual qualities, including resemblance, closeness, and excellent continuity. However, when such grouping is damaged, merging elements such as lines or parts of an item into a cohesive whole becomes impossible. Thus, this model would provide the best explanation for the visual problems that apperceptive agnosia patients experience daily. Concerning the comparison between associative and apperceptive agnosias, apperceptive patients demonstrate strong visual capabilities in acuity and brightness distinction despite having significant challenges recognizing shapes. In contrast, associative agnosia patients can accurately see an item yet cannot recognize these objects because they cannot relate perception to semantic information. Furthermore, study shows that conditions such as Alzheimer's disease may be linked to the prevalence of agnosia since patients with the illness exhibit symptoms of memory impairment and face recognition deficits (Mazzi et al., 2020). Nonetheless, an accurate diagnosis of agnosia involves different tests: Birmingham Object Recognition Test (BORT) and Neuroimaging procedures such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scans. BORT is an efficient testing method that relies on subjects' proclivity to use memory to recall faces and object identities with minimal cognitive stress (Lueptow, 2017). Therefore, this method assists researchers in determining patients' ability to use short- and long-term memories by examining data acquisition, consolidation, and recall levels. On the other hand, neuroimaging techniques help scientists to identify specific areas of the brain that have been damaged, allowing the development of the most effective treatment plans. While there is no direct cure for agnosia, Abela et al. (2019) argue that identifying affected regions in the brain immed...