Orchestrating visual experience: unveiling the nature of feedback processing in object representations and their developmental trajectories

Abstract

Object perception arises from a complex interplay between feedforward and feedback processes within the ventral visual stream, dynamically transforming object representations to shape our visual experience. This thesis combines three experimental studies which reveal the nature of the object representations in human brains. In study 1, the findings demonstrate that the alpha-frequency band serves as a spectral signature of feedback processing, mediating the similarity between veridically perceived and mentally imagined objects. Employing a backward masking paradigm to dissociate feedforward and feedback processes, study 2 provides a detailed account of when, where, and how feedback modulates visual representations during naturalistic object vision. Study 3 reveals the developmental trajectory of visual representations from infancy to adulthood, uncovering changes in their temporal dynamics, representational format, and spectral properties. Together, these studies shed light on the mechanisms and contributions of visual feedback processing in object representations, elucidating how these representations emerge in space and time and evolve throughout brain development.