A computer-aided technique for testing cognitive functions. Validated on a sample of Danes 30 to 60 years of age.

Abstract

With the growing importance of occupational behavioural neurotoxicology the demand for a standardized and reliable cognitive test battery has become urgent. The present study deals with the compilation of a test battery, the purpose of which is to be sensitive to mild brain dysfunction and suitable for modern microcomputer administration and scoring. The battery comprises tests of learning and memory functions specific for each brain hemisphere (Face Recognition Test and Number Learning Test), visuomotor function separately for continuous and discrete tasks (Figure Drawing Test and Pen-to-Point Test), visuospatial function (Parallelogram Test), visual and auditive perception, attention and vigilance (Bourdon-Wiersma Test and Continuous Reaction-Time Test), and concentration (Continuous Graphics Test). The complete test battery was administered and scored on a slightly modified Tektronix 4052 computer with a Tektronix 4956 digitizer as a peripheral device. The validity of the battery was analysed on the basis of a sample of the normal Danish population (N = 1262) stratified for the ages 30, 40, 50, and 60 years, the two sexes, and residence in one of 11 municipalities in the western part of Copenhagen County. Using a 16-dimensional multivariate model comprising biological, social, psychological, and environmental factors, and also examiner behaviour, statistical analyses confirmed hypotheses of influence by the factors Age, Sex, Schooling, and Social Group, i.e. these factors partially explained the variance in the case of almost all the test parameters. Moreover, psychic stress, as determined in a questionnaire, had explanatory power with tests demanding attention and concentration. Hypotheses of effects on test performance by Smoking Status and psychophysiological diurnal or annual rhythms, i.e. Time of Day, and Time of Year, were confirmed for a few parameters, but the effects differed to some extent from those described in the literature. Alcohol Consumption, Drug Consumption Affecting the CNS, Cardiovascular Diseases or Disorders, Metabolic Diseases or Disorders, CNS Injuries or Disorders, and Occupational Activity Status, all revealed by questionnaire, were not found to show the assumed significant effects on test performance. However, a hypothesis of an effect originating in differences between different examiners' behaviour was confirmed for a number of test parameters, although all the test measurements and scorings were done automatically by computer. On the basis of a re-examination of 19 patients previously diagnosed as suffering from diffuse organic psychosyndrome, the sensitivity of the test battery was estimated to be 0.79. The specificity was estimated to be 0.79 on the basis of the results of the original sample.(ABSTRACT TRUNCATED AT 400 WORDS)