Hierarchical relationship between neural mechanisms of ensemble and individual perception revealed through perceptual learning.

Ensemble perception is a critical cognitive function that enables individuals to rapidly comprehend overall situations and identify abnormal or potentially hazardous information. Understanding the neural mechanisms underlying ensemble perception is essential for elucidating how the visual system organizes complex information. Although extensive research has explored various aspects of ensemble perception, the relationship between ensemble and individual perception, as well as the existence of a universal mechanism across different subtypes of visual information, remains unclear. In this study, we conducted three tasks: the single line orientation task, the ensemble line orientation (ELO) task, and the ensemble circle size task. We leveraged the characteristics of perceptual learning, namely specificity and transferability, to investigate the aforementioned questions. Our findings revealed perceptual learning effects across all tasks. Notably, an asymmetrical transfer was observed between the ELO and single line orientation tasks: Training on the ELO task led to significant improvement in the single line orientation task, but not vice versa. Furthermore, the perceptual learning effects observed in the ELO and ensemble circle size tasks did not transfer to each other. These results suggest that a hierarchical mechanism may exist between ensemble and individual perception for the same visual features, while ensemble perception across different types of visual information processing may be governed by distinct mechanisms. Our research provides valuable insights into the neural mechanisms underlying ensemble perception, enhancing our understanding of visual perception processes. (PsycInfo Database Record (c) 2025 APA, all rights reserved).