Essay on An Examination of Visual Agnosia

Visual agnosia refers to the “…inability to recognize objects that results neither from general intellectual loss nor from a loss of basic sensory abilities,” (Anderson, 2009, p. 32). There are generally two types of visual agnosia: apperceptive agnosia and associative agnosia. Apperceptive agnosia is the inability to recognize or draw simple shapes as they are shown or represented. Associative agnosia is the ability to recognize and copy drawings of simple and complex shapes. However, person with associative agnosia are unable to recognize the complex objects (Anderson, 2009).

Eye Vision Inc, a long-standing medical device manufacturer, has signed a contract to sell Holland Hospital the Clear View Laser and a two-year separately priced maintenance plan for $1 million and $0.2 million respectively. On a when-and-if available bais, Eye Vision Inc. will provide software updats that is embedded with the Laser to maintainance purchasor. The software has never been sold without Laser for its functional necessity. In this memo, as explained below, we conclude that:

Yet it takes piles of cliche, over-simplified sketches with only the extremely distinct aspects of your focus to clarify exactly what object you are drawing to finally begin to learn how to truly see what you are looking at. With practice (and an incredible, patient, encouraging art teacher) you learn how to separate what you know from what you are seeing. Starting with copying a signature you are taught to simply flip it over, transforming what you are recognizing in your mind as letters into unidentifiable lines. By doing this it becomes easier to learn how to separate what we know from what we are seeing and mutes the side of your brain telling you to draw what you know, allowing you to copy the shapes and curves of the line without being influenced by what your mind is telling you what you are seeing. By continuing to learn how to separate what you know from what you are seeing you become aware of every little shape, line, and shadow, allowing you to move away from cliches and learn how to draw what is truly in front of

Dr. P, a musician and teacher who had developed visual agnosia, had difficulty processing what he sees, especially faces, he could only identify them by features which he remembered. He only completed tasks if he was singing, if interrupted, he could no longer remember what he was doing nor complete it. Sacks diagnosed Dr. P with prosopagnosia, the inability to identify

According to research, the earliest experimental change blindness is developed from the phenomena such as eye movements and more on working memory. It depends on the personal attention to the images they perceive (MacWhinney, 2001). Although individual have well informed and good memory on whether or not they have perceived an image, they also have poor recalling ability especially on the smaller details that are presented in that image. This is evidently through presentation of the complex pictures that are stimulated

A study conducted by Gusev, Mikhaylova, and Utochkin used the flicker paradigm as described by Rensink et. al (1997) to observe the effect of different stimuli on change blindness. The different stimuli studied were number of objects, object organization, object shape, appearance/disappearance of an object, object shift, color change of an object, and increasing the interstimulus interval (blank screen

In Oliver Sacks’ The Man Who Mistook His Wife for a Hat, he denotes a “deficit is an impairment or incapacity of neurological function; such as loss of speech, loss of language, loss of memory, loss of vision loss of dexterity, or loss of identity” (Sacks, 1985). The specific neurological disorder that is highlighted in chapter one is Visual Agnosia, which is a deficit associated with poor primary visual processing that affects shape perception, figures, object, face and letter recognition (Serino, et al., 2014). Other subtypes of visual agnosia that also seemed to fit the descriptions that Sacks shared is prosopagnosia, which is the inability to recognize human faces (Shah, 2016), and pantomime agnosia, characterized as the inability to understand gestures (Gonzalez, Mack, & Heilman, K., 1986).

The Jelsone-Swain, Smith, & Baylis, (2012), research displays these conclusions provide innovative understandings into the perceptual discrepancies linked with hemineglect and this backups other effort that fabricates the fast denial account of non-awareness dispensation in visual hemispatial neglect.

After investigating spatial cognition and the construction of cognitive maps in my previous paper, "Where Am I Going? Where Have I Been: Spatial Cognition and Navigation", and growing in my comprehension of the more complex elements of the nervous system, the development of an informed discussion of human perception has become possible. The formation of cognitive maps, which serve as internal representations of the world, are dependent upon the human capacities for vision and visual perception (1). The objects introduced into the field of vision are translated into electrical messages, which activate the neurons of the retina. The resultant retinal message is organized into several forms of sensation and is

While head trauma or tumors often induce the "psychic" blindness of these patients, a model has been developed in monkeys by removing all or part of the primary visual cortex. These monkeys are able to respond to visual inputs. They can be trained to touch illuminated bulbs rather than unlit ones and identify certain colors and patterns in order to obtain food. This phenomenon is believed to parallel human blindsight because when trained to respond differently according to whether there is a visual cue or not, these monkeys respond as if there were no cue when a visual input is presented to the blind field (1). It is therefore believed that these animals are able to respond to and identify features of a visual cue even though they do not report seeing it.

Vision is the most important sensory compared to other sensory modality therefore there is a wide range of research carried out on vision. Visual attention is defined as a term that portrays how individuals are able to change their view while attending to an image that is of a normal perspective due to the neurones in the cortex (Carasco, 2011). It is often described as a focal point which is situated with different locations in the region of space (Wright, 1998). Visual search requires detecting a specific target as quickly as possible. For example, trying to find your car in a large car park. By focusing our attention to the specific environment it improves our visual search of the target (Keane et al., 2015). The speed of a visual search

Visual acuity is a measure of an observer’s ability to see fine spatial detail (Cavonius & Schumacher, 1966). There are a number of factors that affect visual acuity, such as illumination and contrast, and various ways to measure it (Kalloniatis & Luu, 2005). One way to measure visual acuity is through target detection which requires the perception of the orientation of a stimulus such as a Landolt C or a Snellen E (Kalloniatis & Luu, 2005). The participant in the current experiment was referred to have their acuity tested. Target detection of a stimulus was used to measure the participant’s visual acuity as a function of retinal eccentricity of the target.

Agnosia is defined as the inability to recognize objects through the processing of sensory information, which means there is no deficit in semantic memory or problems with naming objects. An individual suffering from agnosia still possesses all the relevant semantic information tied to a precept, but they cannot recognize the precept when it is presented to them and therefore trigger the recall of said information. There are many types of agnosia, but this essay will focus on visual object agnosia and prosopagnosia. The former is the inability to recognise objects: patients suffering from visual object agnosia do not have impaired vision, and in some cases can even copy the object they are seeing (patient H.J.A., Humphreys & Riddoch, 1987) or draw it from memory (patient D.F., Milner & Goodale, 1992), but are unable to recognize it when they see it. In the latter, prosopagnosia, patients cannot recognise faces of familiar individuals, and have to rely on other characteristics such as their voice or clothing to recognize them. Patients suffering from prosopagnosia can either acquire it through a lesion in relevant brain areas (acquired prosopagnosia) or for less understood reasons have it from birth, in which case it is termed developmental prosopagnosia. The study of patients with agnosia is integral to the field of visual recognition, as the specifics of their deficits can provide great insight into the ways our brain processes information; for example, the location of

Similarly, both theories are supported by research. Lawson and Humphreys (1996), for example, showed that recognition is affected more by tilt of major axis (foreshortening) than any other rotation, which endorses Marr’s and Nishihara prediction that establishing a central axis is crucial to the process of recognition. Warrington and Taylor (1978) reported that brain damaged patients could recognize objects presented in a typical view only. These patients found difficult to say if two photographs presented simultaneously were the same object when one image was a typical view and the other an unusual view. Although this could be explained as the patient’s inability to transform a 2D version of the atypical view into a 3D model, it could also be due to difficulty in establishing the central axis or due to some features of the object being hidden. In a later study, Humphreys and Riddoch (1984) used images where either the axis had been foreshortened through rotation or a critical feature was hidden. They found that patients had more problems recognizing the images with a foreshortened axis than the ones where a critical feature was hidden. Their

“Just as a painter draws colors and forms from reality to create a representation that