Showing papers by "Werner X. Schneider published in 2005"

Usability of a theory of visual attention (TVA) for parameter-based measurement of attention I: evidence from normal subjects.

Abstract: The present study investigated the usability of whole and partial report of briefly displayed letter arrays as a diagnostic tool for the assessment of attentional functions The tool is based on Bundesen’s (1990, 1998, 2002; Bundesen et al, 2005) theory of visual attention (TVA), which assumes four separable attentional components: processing speed, working memory storage capacity, spatial distribution of attention, and top-down control A number of studies (Duncan et al, 1999; Habekost & Bundesen, 2003; Peers et al, 2005) have already demonstrated the clinical relevance of these parameters The present study was designed to examine whether (a) a shortened procedure bears sufficient accuracy and reliability, (b) whether the procedures reveal attentional constructs with clinical relevance, and (c) whether the mathematically independent parameters are also empirically independent In a sample of 35 young healthy subjects, we found high intraparameter correlations between full- and short-length tests and sufficient internal consistencies as measured via a bootstrapping method The clinical relevance of the TVA parameters was demonstrated by significant correlations with established clinical tests measuring similar constructs The empirical independence of the four TVA parameters is suggested by nonsignificant or, in the case of processing speed and working memory storage capacity, only modest correlations between the parameter values (JINS, 2005, 11, 832–842)

Usability of a theory of visual attention (TVA) for parameter-based measurement of attention II: evidence from two patients with frontal or parietal damage.

Abstract: Based on a ‘Theory of Visual Attention’ (TVA), whole and partial report of brief letter arrays is presented as a diagnostic tool to estimate four clinically significant attentional components: perceptual processing speed, visual working memory storage capacity, efficiency of top-down control, and spatial distribution of attention. The procedure used was short enough to be applicable within a standard clinical setting. Two brain-damaged patients, selected based on lesion location and neuropsychological test profile, were compared to a control group of 22 healthy subjects. One patient with a right inferior parietal lesion showed a pattern of non-spatially and spatially lateralized attention deficits that is typically found in neglect patients. Results from the second patient supported the decisive role of superior frontal brain structures for top-down control of visual attention. This double dissociation supports the hypothesis that, even with a short version of whole and partial report, valid and meaningful results can be obtained in the neuropsychological assessment of attention deficits. The potential and constraints of TVA-based parameter estimation for the clinical application are discussed. (JINS, 2005, 11, 843–854.)