The determinants of consciousness of human faces

From what we see to what we hear and from how we feel to what we think, our conscious experiences play an important role in shaping our lives. Because we become aware of only a small subset of our ongoing cognitive and perceptual processes1–4, explicating the determinants of conscious experiences is a crucial step towards understanding human behaviour. Here we develop a computational data-driven approach for studying the determinants of consciousness and we use it to investigate what is arguably the most important social stimulus: the human face5–7. In six experiments with 174 participants, we used this method to uncover a reliable dimension that determines the speed with which different faces reach conscious awareness. This dimension correlates strongly with the perceived power/dominance of a face. We show that the dimension cannot be explained by low-level visual factors and does not describe conscious processing, thereby suggesting that it captures the process of prioritization for consciousness. By visualizing the dimension, we are able to produce a vivid depiction of what unconscious processes prioritize for conscious processing. We propose this method as a means to study the contents and neural correlates of conscious experiences across various domains.