Current neuroscience situates cognition within cortical and (to a less extent) subcortical areas, relegating receptors to passive relays. We propose a receptor-centered framework in which receptors act as constitutive determinants of neural architecture and cognitive experience, supported by empirical studies that substantiate our interpretation. Opsin gene therapy altering color vision in adult primates, as well as cross-modal reorganization in congenital or acquired human blindness, show that natural or artificial modifications of receptor repertoires can reshape cortical maps and perception. Mechanoreceptors and proprioceptors can sustain the representational scaffolds for agency, motor planning and body schema, while the interoceptive receptors that detect respiratory, cardiovascular and visceral states can modulate affect, memory and perceptual awareness. Also, we propose that gut bacteria may contribute to cognition through receptor-mediated signaling, where microbial metabolites interact with neural, immune and endocrine receptors to influence mood, motivation and higher cognitive processes. We argue that receptor guidance may extend upward into cognition: mental imagery, sensory substitution and synesthesia point towards imagination and abstract thought as recombination of receptor-derived primitives. Comparative neurobiology reinforces our claims, showing that distinct receptor repertoires yield species-specific perceptual worlds such as echolocation in bats, polarization vision in cephalopods or magnetoreception in birds, each shaping unique cognitive landscapes. Overall, cognition could be described as a multilevel process in which cortical activity is driven by receptor-encoded informational templates that are established across phylogeny, ontogeny and individual experience. To think is to reconfigure receptor traces, while to imagine differently is to sense differently.
Arturo Tozzi (Wed,) studied this question.