VS — A new computer program for detailed offline analysis of visual-spatial perception

Abstract

A new IBM-AT-compatible software program, VS, for the analysis of visual-spatial (VS) perception in humans, especially brain-damaged patients, is described. VS is suitable for analysis of the following visual-spatial tests: (1) subjective visual vertical (SVV), (2) subjective visual horizontal (SVH), and (3) orientation, length, distance, form and position discrimination, as well as line/bar bisection. The program allows manipulation of a wide range of experimental tasks by varying relevant parameters, e.g., length, width, color, movement direction, step width, and position on screen of the stimuli. Psychophysical parameters are computed (methods of limits) and stored in dBASE files which can be retrieved for further data analysis with commercial statistics or graphics software. VS has a versatile text editor with two macro languages which enables the user to define their own experimental configurations and realize individual graphic plots on screen or laser printer. VS incorporates two standard examinations together with normative data of control subjects and standard plots of the subject's performance. The results of separate investigations show highly stable results in normal control subjects in repeated examinations as well as good retest-reliability of these standard examinations in brain-damaged patients ( r tt = 0.77). Representative case reports of a patient with left-sided visual neglect, a patient with Balint's syndrome as well as a patient with visual-spatial deficits subsequent to a left parietal brain lesion demonstrate the sensitivity and specificity of the program.