Goal of research: the study of the temporal dynamics of the processes of attention, perception and decision-making, identifying patterns of development and interaction of effects of the stimulus history, automated early stages and late conscious stages of information processing, identification of differences in the patterns of brain activity accompanying correct and incorrect decisions, as well as mechanisms of preparation for the decision and mechanisms for assessing the results of the accomplished act.
Methodology: the work was based on electroencephalography recording during a new experimental task with a high cognitive load developed by our laboratory, as well as magnetoencephalography recording during the implementation of the modified task of holistic perception developed by our laboratory.
Empirical base of research: studies were conducted on volunteers who signed the informed consent to participate in the experiment. Studies were carried out in full compliance with ethical standards in accordance with the Helsinki Declaration of Human Rights and subsequent amendments thereto. During the experiments physiological parameters (electroencephalography, magnetoencephalography and others) and behavioral parameters (response time, correctness of response, etc.) were recorded.
Results of research: The present study produced the main results as follows.
The amplitude of the evoked potential component P2 was increased before errors compared with the correct answers, as well as at the situation in the passive attention compared with the active attention. These effects suggest suppression of preattentional automatic information processing of an incoming stimulus - adequate in passive conditions, but leading to an error in the active task. The amplitude of evoked potential component N2 was shown to be reduced before errors, indicating that an error occurs as a consequence of reduced level of executive attention and cognitive control.
The absence of differences in the P3 component of the evoked potential before errors compared with the correct answers indicates that during the time interval of the stimulus recognition and decision the erroneous information remains indistinguishable from the true information.
The spectral power of the alpha rhythm was shown to be reduced before errors compared with the correct answers, indicating the connection of error commission with prestimulus state characterized by elevated levels of cognitive conflict and having a top-down nature. Power of alpha-rhythm increased during expectation of the target stimulus, indicating that the corresponding increase in the level of executive attention.
The holistic perception of the stimulus was shown to be accompanied by a decrease in the activation of the primary sensory areas during the early stages of automatic (preattentional) analysis of the stimulus. This result indicates that the process of detection of a holistic image is preceded by a process of "sparse coding".
Thus, as a result of the research, the important effects of the dynamics of the processes associated with attention, perception and decision-making were identified and described for the first time. In particular, the present work demonstrated that the early preattentional automatic processes are critically dependent on the tonic background state defined by descending influences (including the participation of conscious control). Failures at the stage of early automatic processes influence the decision and the action execution, not manifesting itself during the later, conscious processes of attention and perception.
Novelty, importance and practical applicability of the results:
The novelty of this study on the methodological level is that we for the first time used a new experimental task, which combines the advantages of condensation task and oddball task - high cognitive load, high expression of both early and late components of the evoked potential, the presence of distractors, allowing to explore the current brain state in between the relevant target stimuli.
The theoretical novelty of this study is that it for the first time explicitly demonstrated spontaneous interaction effects between these levels of attention. Moreover, it shows for the first time in human neuroimaging literature the effects of "sparse coding" during the early preattentional stages of holistic image processing, determining the next steps of conscious image perception.
The relevance and significance of this study is determined by that it is aimed at solving the fundamental problem of the internal structure of the processes leading to the decision, as well as to the resolution of theoretically and practically urgent problem of finding precursors and psychophysiological conditions leading to high- and low-effective human performance.The methodology developed during the implementation of this work, and the results obtained open up a new direction of psychophysiological research of attention as a system efficiency factor, which organizes the processes of perception and action. The current studies for the first time identified and described the sequence of events in the pipeline of processes from perception to decision-making, which are guided by the processes of attention, and their important temporal characteristics. The results of this study make it possible to expand the fundamental understanding of the brain mechanisms of cognitive processes, as well as they may have practical applications in the field of psycho-diagnostics and professional selectio