When Task Seems Easier: The Influence of Illusory Target Size on Hitting Accuracy

Abstract

The article investigates the influence of subjective beliefs about one's efficiency on the results of sensorimotor activity through experimental studies using size illusions. Sensorimotor learning is a process of increasing the efficiency of activity as it is practised. It involves a two-way relationship between performance expectations and performance outcomes. Performance expectations are subjective beliefs about the likely success of a particular task. Visual illusions are often used to investigate this relationship. Illusorily larger targets are perceived as easier compared to illusorily smaller ones; as a consequence, subjects are more efficient at hitting targets that appear easier to them. However, results that do not fit the model are still observed. The paper proposes an explanation for the inconsistent results by a possible "failure" in a three-level mechanism involving replication of the size illusion, perception of targets as different in difficulty, and changing performance prediction according to difficulty. The paper analyses the design and results of 18 experimental studies conducted from 2012 to 2023 and suggests possible modifications of the experimental paradigms at each of the three levels of the mechanism of the effect of performance prediction on sensorimotor activity.