VS - A NEW COMPUTER-PROGRAM FOR DETAILED OFFLINE ANALYSIS OF VISUAL-SPATIAL PERCEPTION

A new IBM-AT-compatible software program, VS, for the analysis of visu al-spatial (VS) perception in humans, especially brain-damaged patient s,is described. VS is suitable for analysis of the following visual-sp atial tests: (1) subjective visual vertical(SVV), (2) subjective visua l horizontal (SVH), and (3) orientation, length, distance, form and po sition discrimination, as well as line/bar bisection. The program allo ws manipulation of a wide range of experimental tasks by varying relev ant parameters, e.g., length, width, color, movement direction, step w idth, 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 g raphics software. VS has a versatile text editor with two macro langua ges which enables the user to define their own experimental configurat ions 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 n ormal 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-sid ed visual neglect, a patient with Balint's syndrome as well as a patie nt with visual-spatial deficits subsequent to a left parietal brain le sion demonstrate the sensitivity and specificity of the program.