Is reentry critical for visual awareness of object presence?

Reentrant processing has been proposed as a critical mechanism in visual perception of an object's features. In order to test whether reentry is critical for visual awareness of object presence, the success of reentry was manipulated with object substitution masking (OSM) while participants performed a forced-choice target present-absent task and rated their subjective confidence in each trial. Signal detection analyses were performed on the data from the forced-choice task and on the subjective confidence ratings. The results showed that OSM reduced sensitivity to the presence of the target, indicating that reentry is critical for awareness of object presence. Consistent with the idea that OSM leaves feedforward processing intact, confidence ratings in reported target-absent trials were lower for misses (target present, no response) than for correct rejections (target absent, no response), implying that a target-related sensory signal was available for subjective ratings in spite of reported absence of the target. The results suggest that reentry is critical for encoding the target representation into a stable, consciously reportable form.