Reaction time indicators for assessing cognitive functions

Cognitive abilities in neurodegenerative diseases begin to alter much earlier than the main clinical pathomorphological core of the disease develops, while patients for many years do not demonstrate pronounced clinical manifestations amid active functioning compensatory mechanisms. Subsequently, the leading symptom complex formed against the background of decompensation becomes practically insensitive to modern drug treatment. In this regard, the search for early manifestations of cognitive and neurological changes that could serve as reliable markers of the development of the neurodegenerative process, is a relevant task of diagnosing these diseases. Currently, in practical work, psychiatrists and neurologists mostly use blank cognitive tests for screening diagnostics of cognitive disorders based on questionnaires with scaled results, sensitivity of which is high for the stages of advanced disease, but is not enough for the stages of prodrome cognitive impairment. Therefore, the creation of a tool for objective screening of early stages of cognitive impairments, combining efficiency and ease of use, is an important and modern direction of neuroscience. Suggested review aims to analyze and summarize available data on the change in reaction speed at the onset of neurological diseases. The need for modernization of neuropsychological diagnostics with the help of possible integration of sensorimotor tests with computer technology is revealed. It should improve the reliability and accessibility of the screening assessment. It is shown that, apart from simple reaction (SRT), such reaction indicators as reaction time variability (RTV), choice reaction time (RTT) and the dynamic of reaction time are the objective and independent markers of efficiency of information processing by the nervous system.