Visual awareness and anisometry of space representation in unilateral neglect: A panoramic investigation by means of a line extension task
Graduate studies at Western
Consciousness and Cognition 7 (3):327-355 (1998)
|Abstract||Ninety-one right brain-damaged patients with left neglect and 43 right brain-damaged patients without neglect were asked to extend horizontal segments, either left- or rightward, starting from their right or left endpoints, respectively. Earlier experiments based on similar tasks had shown, in left neglect patients, a tendency to overextend segments toward the left side. This seemingly paradoxical phenomenon was held to undermine current explanations of unilateral neglect. The results of the present extensive research demonstrate that contralesional overextension is also evident in most right brain-damaged patients without contralesional neglect. Furthermore, they show that in a minority of left neglect patients, the opposite behavior, i.e., right overextension can be found. The paper also reports the results of correlational analyses comprising the parameters of line-extension, line-bisection, and cancellation tasks, as well as the parameters relative to the Milner Landmark Task, by which a distinction is drawn between perceptual and response biases in unilateral neglect. A working hypothesis is then advanced about the brain dysfunction underlying neglect and an attempt is made at finding an explanation of neglect and the links between the mechanisms of space representation and consciousness through the study of the changes induced by unilateral brain lesions in the characteristics of space-coding neurons. Abbreviations: C, control group;GN+91,full group of neglect patients;GN+27,group of neglect patients with relative left overextension;GN+14,group of neglect patients with relative right overextension;GN-43,full group of non-neglect patients;GN-9,group of non-neglect patients with relative left overextension; H canc, H cancellation task; LE, left extension; LE/RE, ratio of left-right extension; N+, neglect patients; N-, non-neglect patients; PB Land-M, perceptual bias on Landmark motor task; PB Land-V, perceptual bias on Landmark verbal task; RB Land-M, response bias on Landmark motor task; RB Land-V, response bias on Landmark verbal task; RE, right extension.|
|Keywords||No keywords specified (fix it)|
|Categories||categorize this paper)|
|Through your library||Configure|
Similar books and articles
Anna Berti (2002). Unconscious Processing in Neglect. In Hans-Otto Karnath, David Milner & Giuseppe Vallar (eds.), The Cognitive and Neural Bases of Spatial Neglect. Oxford University Press.
John Driver & Patrik Vuilleumier (2001). Perceptual Awareness and its Loss in Unilateral Neglect and Extinction. Cognition 79 (1):39-88.
L. Deouell (2002). Pre-Requisites for Conscious Awareness: Clues From Electrophysiological and Behavioral Studies of Unilateral Neglect Patients. Consciousness and Cognition 11 (4):546-567.
M. Kinsbourne (1993). Orientational Bias Model of Unilateral Neglect: Evidence From Attentional Gradients Within Hemispace. In John Marshall & Ian Robertson (eds.), Unilateral Neglect: Clinical And Experimental Studies (Brain Damage, Behaviour and Cognition). Psychology Press.
M. Behrmann & D. V. Meegan (1998). Visuomotor Processing in Unilateral Neglect. Consciousness and Cognition 7 (3):381-409.
Paolo Bartolomeo & Sylvie Chokron (2002). Can We Change Our Vantage Point to Explore Imaginal Neglect? Behavioral and Brain Sciences 25 (2):184-185.
Bill Brewer (1992). Unilateral Neglect and the Objectivity of Spatial Representation. Mind and Language 7 (3):222-39.
Peter W. Halligan & John C. Marshall (1998). Neglect of Awareness. Consciousness and Cognition 7 (3):356-380.
E. Bisiach, M. Neppi-Modona, R. Genero & R. Pepi (1999). Anisometry of Space Representation in Unilateral Neglect: Empirical Test of a Former Hypothesis. Consciousness and Cognition 8 (4):577-584.
Added to index2009-01-28
Total downloads18 ( #74,621 of 739,406 )
Recent downloads (6 months)3 ( #26,423 of 739,406 )
How can I increase my downloads?