Alpha and Theta Rhythms as Markers of Cognitive Effort

Abstract

Introduction. This review article combines the theory of motivational intensity and the theory of mental effort with studies of oscillatory correlates of the performance of complex cognitive tasks. The phenomenon of effort has been a longstanding subject of research in fundamental psychology. Theories describing the cognitive mechanisms of mental effort have been developed in recent years. However, further research is needed to explain the mechanism of effort modulation during task performance. Theoretical justification. Mental effort can be defined as an active volitional process of mobilizing resources to maintain a particular behavior. The theory of motivational intensity, in conjunction with theories of mental effort, describes the cognitive and motivational factors that modulate the effort invested in the performance of a task. Interpreting the oscillatory correlates of individual cognitive processes in the context of effort theories may allow one to develop an understanding of the mechanism underlying the distribution and modulation of mental effort. The purpose of this paper is to review the existing experimental data on the modulation of task-related oscillations and compare the research results with the predictions of force theories. Results. The article reviews research on the power of oscillations as correlates of various controlled processes required by a cognitive task. The severity of the oscillatory effects associated with the performance of the task increases with the complication of the task and with increased motivation to perform. When performing particularly complex tasks, there are individual differences in indicators of brain activity, which, apparently, can only be explained through the motivational-emotional reaction of the subject to complexity. Discussion of the results. The effects found as a result of the literature review are consistent with the predictions of the theory of motivational intensity about the modulation of effort. However, to date, there is a lack of research to correlate oscillatory data with theories of effort and develop an understanding of the mechanism of force modulation under various task requirements. The article discusses possible studies on this topic and the features of the required experimental designs.

Keywords

• mental effort
• motivational intensity
• brain oscillations
• electroencephalography
• magnetoencephalography
• alpha rhythm
• theta rhythm
• complex tasks
• motivation
• cognitive abilities