Abstract:

Cognitive effort is the active and volitional mental investment that individuals make during the process of processing information, engaging in thinking, and making decisions, in order to override established habits and achieve intended goals. This effort not only encompasses the degree of engagement demanded by high-demand tasks but is also typically accompanied by an aversive subjective experience. Research on cognitive effort has a long history, yet the concept of cognitive effort remains insufficiently clear. Although it is not equivalent to motivation, willpower, or difficulty, nor is it equivalent to attention or cognitive control, it is closely related to these concepts. Currently, academic circles have carried out a large number of empirical studies on cognitive effort from different perspectives. Based on different research purposes, these empirical studies have different understandings of the concept of cognitive effort, highlight different dimensions of the connotation of cognitive effort, and propose significantly different operational definitions, thereby developing a variety of different measurement methods and experimental paradigms. On the whole, they have promoted the research on cognitive effort, but they vary in terms of measurement indicators, manipulation of the core functions of cognitive effort and effort levels, etc., which makes the academic circle lack recognized, repeatable measurement methods and experimental paradigms that can accurately adapt to the multidimensional characteristics of cognitive effort.

In summary, the current measurement methods can be categorized into self-report scales (2 types) and experimental methods (11 types). The self-report scales include the Need for Cognition Scale and the NASA Task Load Index. According to the differences in the core cognitive functions involved in the measurement methods of cognitive effort, experimental methods can be divided into the following four categories: experiments based on working memory (including N-back Task, Cognitive Challenge Task, and Cognitive Effort Motivation Task), experiments based on response conflict (including Cognitive Performance Task, Number Judgment Task, and Simon-like Dot-Motion Conflict Task), experiments based on attention (including Number Switching Task, Rapid Serial Visual Presentation Task, Odd-ball Discrimination Task, and Visual Blur Search Paradigm), and experiments based on digital operation (containing Mental Arithmetic Task in two forms).

However, self-report scales still have the following inadequacies: although these two scales have been widely applied in the research on cognitive effort, since the initial purpose of developing these scales was not to measure cognitive effort, the validity and reliability of their application in the actual research within the field of cognitive effort still remain to be examined. Furthermore, the accuracy and reliability of the measurement results of the scales are not only prone to be interfered by factors such as individuals' metacognitive abilities but also easily affected by individual differences, testing environments, and cultures. Experimental methods also have certain flaws: if the manipulation of cognitive effort and difficulty in the experimental design is inappropriate, it will easily lead to the confusion between the two; differences in cognitive abilities among individuals will influence their perception of task difficulty; different difficulty levels of experimental tasks are likely to cause the time discount effect; in addition, the theoretical heterogeneity of cognitive effort results in the diversification of measurement methods, and the validity of each measurement tool needs to be verified. Based on the complexity of the subjective cost of cognitive effort, there are currently three main theoretical models regarding the cost of cognitive effort: the internal cost model, the opportunity cost model, and the signal model. The internal cost model focuses on explaining why individuals are willing to invest more cognitive effort to achieve their goals; the opportunity cost model focuses on explaining why individuals are willing to give up other opportunities to reach their goals; the signal model focuses on explaining why individuals are willing to choose to complete something that they did not want to do originally.

Future research should enhance the accuracy and reliability of the use of scales; integrate interdisciplinary technologies to separate cognitive effort from difficulty levels; dynamically calibrate individual differences and conduct multi-modal verification of cognitive effort; innovate measurement theories and methods to meet different research needs.

Key words: cognitive effort, measurement methods, improvement recommendations