Searching for visuomotor matches versus mismatches biases confidence and visual sampling strategies

Abstract

Visuomotor self–other distinction relies on the comparison of forward predictions from one’s motor system with visual movement data. Previous work suggests that matching kinematics may be preferentially processed, but at the same time, visuomotor mismatches are known to capture attention. Here, participants were presented four virtual hands, each reflecting their actual hand movements, conveyed via a data glove, with a unique added time delay. Participants had to identify which of these hands moved most similarly (search for match) or most differently (search for mismatch) to their actual movements under high or low task difficulty (i.e. relative similarity of delay mappings). Detection accuracy did not differ between search instructions on average but was less strongly affected by task difficulty when searching for visuomotor matches than when searching for mismatches. Furthermore, despite comparable performance, participants reported significantly higher confidence in their choices when searching for visuomotor matches than when searching for mismatches. Finally, eye tracking showed participants relied significantly more on serial sampling of the hands when searching for matches, whereas they retreated to central fixation (and thus probably peripheral vision for simultaneous sampling) when searching for mismatches.