The levels of perceptual processing and the neural correlates of increasing subjective visibility.
Consciousness and cognition October 1, 2017 Marek Binder, Krzysztof Gociewicz, Bert Windey et al.
Transitions from unconscious to conscious perception may be more gradual for low-level visual features and more dichotomous for high-level features. In an fMRI study using backward masking, participants reported a target digit's magnitude (high-level) or its color (low-level) and rated visibility. Intermediate visibility was reported more often in the low-level task, supporting the levels-of-processing hypothesis. Visible targets activated insulo-fronto-parietal regions in both tasks, while visual areas showed higher activity in the low-level task across all visibility levels. The findings suggest that attentional modulation of feature-representing brain regions mediates how processing level shapes conscious perception.