The search for neural correlates of consciousness (NCCs) is a central framework in consciousness science, often praised for its metaphysical neutrality. However, this framework implicitly assumes a specific model of consciousness—the Lite-Brite model—whose plausibility is an open question, making the NCC framework structurally biased. As an alternative, the authors propose a Difference-Maker framework that searches for difference makers of consciousness (DMCs) instead of mere correlates. Drawing on interventionist ideas in philosophy of science, they argue that shifting to DMCs would alter both experimental practice and how existing results are interpreted, offering a more neutral and productive approach.
A conscious being has a subjective point of view on the world and its own body, a concept easiest to grasp with vision, as Ernst Mach illustrated by drawing his own visual perspective. However, subjective experience encompasses far more than vision, including sounds, odors, tastes, and tactile sensations—a complete sensory world. The text argues that these sensory experiences constitute a full subjective point of view, extending beyond any single sense to shape a person's entire conscious experience of reality.
The capacity for subjective experience—basic awareness of the world without reflection—is supported by integrated midbrain and basal ganglia structures, which are among the oldest and most conserved brain systems in vertebrates. This suggests that subjective experience is widespread and evolutionarily old within the vertebrate lineage. The insect brain supports functions analogous to the vertebrate midbrain, so insects may also have a capacity for subjective experience. The authors discuss which neural features can and cannot support this capacity and relate their neurobiological arguments to the 'hard problem' of consciousness.