- Pp. 94-112 (19)Paulo J. Negro
The olfactory system provides an especially propitious model for the study of neuronal correlates of consciousness. Olfactory signals mostly bypass thalamic firstorder relay neurons and directly affect the olfactory cortex. In the olfactory cortex, the sparse distribution of odor-induced activity and the selective odor tuning of individual pyramidal cells resembles the hippocampus place field and place cells. In mammals, the olfactory cortex gave origin to the isocortex. The realization of information in this region may play the role of a heuristic process for the realization of information in other cortices. Binding of information in the olfactory cortex results from specific focal signaling in the context of widespread activation. Odorants bind to odorant receptors (OR) on the surface of olfactory sensory cells and activate neural maps in the olfactory bulb (OB). This process happens through the synchronization of localized tufts cells and the wide activation of mitral cells, and it fits with the information.expectation model of realization of information. The OB depicts odorant characteristics in spatiotemporal patterns. The piriform cortex (PC), considered the primary olfactory cortex, generates pattern recognition beyond the OB maps. Much like the hippocampus, PC oscillatory activity establishes cellular synchronicity thorough the ensemble and across the oscillatory phase. The posterior PC integrates structural codes into more highly processed representations of odor qualities, considered odor-object categories. The existence of odor-objects is consistent with the manipulation of information as a focal aspect of subjective experiences. Active mapmaking realizes information that transcends into qualia. The process of mapmaking represents a synthetic de novo phenomenon with a relational origin. Olfactory experiences are abstracted from the binding of specific molecules to olfactory receptors into structurebased categories, and further on into odor-object categories. Transitions happen under feedback input, in agreement with Predictive Coding. The overall process parallels the hierarchy of abstractions instantiated in the insula. The transition of external information into organism-centric encoding supports the idea of qualia as conveyors of adaptive information. The synthesis of low dimensional percepts supports the transition from the Bayesian calculations of Predictive Coding to phenomenal heuristics.