Human Action Planning and Mental Rotation in a Tetris-Like-Game

The mechanisms behind human action planning and mental object manipulation are still not well understood. These core cognitive abilities are essential not only for interaction with physical spaces, e.g., for assembling objects, but also for effective problem-solving in the digital world. Here we ask, which strategies humans employ when assessing whether or not an object will fit into a cavity. To this end, objects and cavities were presented with different orientations on a computer screen and we measured errors, reaction-times and gaze patterns, where the latter can point to different problem-solving strategies. On the one hand our findings confirm that simpler configurations are solved faster and more efficiently than more complex ones. On the other hand, by analyzing about 80,000 gazes, we observed that participants used three different strategies. In many instances, the investigated task -- featuring relatively large objects -- could be completed using only peripheral vision (37%). In a larger number of cases quite "specific" gaze patterns were observed, primarily focusing on the Gestalt of a concave corner (46%). Less frequently, but still notably often, participants employed a strategy of fixating near to object or cavity (17%), potentially minimizing the length of the required saccadic eye movements while relying on perifoveal/peripheral vision. Ultimately, these findings highlight the crucial roles of proximity, spatial orientation, and visual cues in object recognition tasks, suggesting that the perceptual strategies used depend on distinct aspects of the object configurations.