Top-down and bottom-up attentional responses to manipulations of perceptual organization in a complex visual Image: A flicker task study using a medieval mosaic as a case study

The perception of art involves a complex interplay of bottom-up and top-down attentional processes, which are shaped by principles of perceptual organization. In this study, we investigated how systematic manipulations of visual features governed by Gestalt principles affect attentional deployment in a highly structured image. Using the apse mosaic of Saint Agnes Outside the Walls as a stimulus for a case-study, thirty participants performed a flicker change-detection task. Variations of spatial and chromatic symmetry, figure-ground ratio, and size of the central figure were introduced. Reaction time and response correctness to marginal and central interest changes were measured. Departures from perceptual regularities were associated with increased response times. Moreover, under specific conditions involving figure-ground alteration and enlargement of the central figure, a reversal of the typical flicker task effect was observed, with faster detection of marginal than central changes. These results suggest that disruptions of perceptual organization modulate the balance between automatic and controlled attention during visual processing. The present study contributes to knowledge about the impact of visual complexity, emphasizing the active and adaptive character of involved cognitive mechanisms.