The scope of unconscious processing remains hotly debated, driven by diverse methods for manipulating and measuring perceptual awareness. Through dialogue among researchers with varied theoretical backgrounds, ten recommendations and nine outstanding issues are provided for designing experimental paradigms, analyzing data, and reporting results. These guidelines aim to evoke discussion about norms in studying unconscious processes and help researchers make informed decisions. While some recommendations may not align with existing approaches and will likely evolve, they are intended to foster a more convergent understanding of the extent and limits of unconscious processing.
Identifying neural correlates of perceptual consciousness (NCC) remains difficult because most studies use non-invasive brain measures that lack the spatial or temporal precision to separate consciousness from other cognitive processes. Low sensitivity also makes null findings hard to interpret. This review argues that human intracranial recordings—which offer high spatiotemporal resolution, better signal sensitivity, and broad brain coverage—can advance the search for NCCs. It examines studies at the single-neuron and population level, evaluates their implications for debates between cognitive and sensory theories of consciousness, and discusses current limitations and future directions using emerging technologies and experimental paradigms.