Normative Assessment of Cognitive Functions with on the Brief Assessment of Cognition in Schizophrenia (BACS) Scale in the Tomsk Population: Constitutional Factors of Variability

The article provides arguments in favor of developing ideas about cognitive functions and their implementation not only in the practice of scientific knowledge, but also in everyday life. The relevance of the study is due to the priority links with psychosocial functions and cognitive management of public life. The aim of the study was to provide a normative assessment of cognitive functions using the Brief Assessment of Cognitive Functions in Patients with Schizophrenia (BACS) scale in the Tomsk population of healthy individuals. Our objectives were to determine the nature and severity of cognitive functions in the representation of the BACS scale in a group of healthy individuals in the study of the normative indicators variability in different populations; to determine the influence of constitutional factors (gender, age) on the variability of cognitive functions (CF) indicators; to carry out a comparative analysis with the data obtained from other normative indicators studies; to determine the variability of CF indicators in the covariance-dispersion representation; to determine the co-variability of CF indicators in the covariance-dispersion representation. The sample consisted of 161 people without mental disorders living in Tomsk. The age ranged from 20 to 69 years old. The markers of the state of cognitive functions are the assessments of the BACS scale. The BACS scale meets the requirements for rapid assessment of the cognitive functions state and includes tasks for evaluation of planning and control functions, speech fluency, working memory, and motor skills. This study keeps developing ideas about cognitive indicators of the Russian population norm. The article examines the gender and age influence on the scale assessments. Statistically significant decrease with age in male and female subpopulations for all tests is shown. The most significant decrease is noted for test scores "Symbol Coding" and "Tower of London". Comparative analysis of the state of cognitive functions shows that in the Tomsk population "Token Motor" and "Verbal Fluency" indicators were higher and other test indicators were significantly lower than those of the Moscow sample. The variability of the scale values is found to be due to such constitutional factors as age and gender. According to ANOVA data, gender and age significantly influences the mean scores of test performance. Based on the calculations of the covariance-dispersion matrix, it is shown that cognitive functions are highly connected in the male subpopulation. Comparison of empirical data from different study groups shows that the BACS reveals high validity with respect to measurable attributes and sensitivity to regional variability in CF indices. The scores can be used as normative for the Tomsk population when studying neurocognitive deficits in patients with schizophrenia.