Advantages of visual object and space perception battery

Advantages of visual object and space perception battery Ans. Neuropsychological assessment is incomplete without the visual and space perception (Warrington shape detection, incomplete letters, silhouettes, object decision, dot counting, progressive silhouettes, position discrimination, number allocation and cube analysis (Warrington & James, 1991 as cited in Gorayska & Mey, 2004). Advantages of VOSP Brenda Rapp (2001) has stated that, â€Å"highly sophisticated methods of cognitive assessment can be developed if one uses as a starting point a detailed theory of relevant cognitive system† (Rapp, 2001, p.4). Good examples for theory based assessments methods for visual perception are Birmingham Object Recognition theory (BORB) (as given by Humphreys & Riddoch, 1993) and VOSP (Warrington & James, 1991). VOSP is made on Warrington’s model (Warrington & McCarthy, 1990 as cited in Lara et al., 2004). The model puts forward three subtypes of impaired object recognition. They are, â€Å"disorders of visual sensory discrimination † (Lara et al., 2004, p.386), apperceptive agnosia and associative agnosia. â€Å"Disorders of visual sensory discrimination reflect selective deficits affecting sensory processing including acuity, shape, discrimination and colour discrimination† (Lara et al., 2004, p.386), apperceptive agnosia is impaired object perception (Lara et al., 2004) and associative agnosia is when an individual is unable to derive meaning of the object presented despite having normal perceptual and sensory abilities(Lara et al., 2004). Thus, it can be inferred that object perception is not possible without object recognition in Warrington’s model (Lara et al., 2004) and it points out that object perception is an, â€Å"adequate integration of sensory, perceptual and representation information (Rapport, Millis & Bonello, 1998) in a complex analytical task that integrates perceived details into an organized structure (McCarthy &Warrington, 1990)† (Lara et al., 2004, p. 386). Cogn itive state of visual perception can be better understood with VOSP in normal and pathological population (Lara et al., 2004). For example, when VOSP was administered to patients of Alzheimer’s disease, impairment was found only in the silhouette subtest of VOSP (Binetti et al., 196 as cited in Lara et al., 2004). This suggests that early perceptual processes are still intact in patients who are in the initial stage of Alzheimer’s disease (Binetti et al., 196 as cited in Lara et al., 2004). VOSP is clearly a test of object recognition and space perception and nothing else. The is due to the reason , VOSP is made of different tests which includes tasks which are so designed that they assess specific dissociable aspects of object and space perception (Lawrence et al., 2000 , p.1350). Every task of the test focuses on a particular aspect of visual perception being completely independent of other cognitive and motor processes (Lawrence et al., 2000). Hence, VOSP can be reg arded as a sensitive test battery. The authors of VOSP have stated, â€Å"Any number of the eight individual tests may be administered and there is no prescribed order (Warrington & James, 1991, p.7)† (Merten, 2006, p.460). This is a very useful thing to do. It is very practically next to impossible to administer the complete set of tests of VOSP as part of neuropsychological assessment because it will be quite a time consuming process (Merten, 2006). Moreover, as advised by Lasogga & Michel (1994 in Merten,2006), easy to use screening measure can be used to test initial visual perception on the suspected group and only those showing visible deficits will be asked to go through the complete assessment (Merten, 2006).