No watershed for overflow: Recent work on the richness of consciousness

A familiar and enduring controversy surrounds the question of whether our phenomenal experience “overflows” availability to cognition: do we consciously see more than we can remember and report? Both sides to this debate have long sought to move beyond naïve appeals to introspection by providing empirical evidence for or against overflow. Recently, two notable studies—Bronfman, Brezis, Jacobson, and Usher (2014) and Vandenbroucke, Sligte, Fahrenfort, Ambroziak, and Lamme (2012)—have purported to provide compelling evidence in favor of overflow. Here I explain why the data from both studies are wholly consistent with a “no overflow” interpretation. Importantly, when framed purely in representational or informational terms, this “no overflow” interpretation agrees with the interpretations respectively offered by both Bronfman et al. (2014) and Vandenbroucke et al. (2012). The difference only emerges when additional assumptions are made concerning which representations correspond to elements in conscious experience. The assumptions made by overflow theorists are contentious and poorly motivated. However, challenging them simply reopens the original controversy. The upshot is a sobering moral: we still do not know how to move beyond appeals to naïve introspection in establishing the nature and limits of our ordinary experience.