Scientific Understanding of Consciousness |
Antonio Domasio’s Convergence ZonesThere are in the order of thousands of convergence zones, which are all microscopic neuron ensembles, located within the macroscopic convergence regions that have been cytoarchitectonically defined and that number about one hundred. (Domasio; Convergence Zone, 71) A convergence zone is a means of establishing, through synaptic strengthening, preferred feedforward/feedback loops that use subsets of neurons within the ensemble. (Domasio; Convergence Zone, 72) Access to concrete knowledge of higher hierarchical status requires structures in anteriorly placed temporal cortices, whereas access to concrete knowledge of lower complexity only requires posterior occipital cortices. (Domasio; Convergence Zone, 68) Top steps in the hierarchy are the most distant convergence points from which divergent retroactivation can be triggered. (Domasio; Convergence Zone, 70) Cells in high-order cortices forming the hierarchy of convergence zones are critical for the neural process of memory reenactment, but they are neither the "sole basis for" nor the "explicit site of" that neural process. There is no single basis or site for such a process. Each memory reenactment can utilize slightly different neural assemblies. (Domasio; Convergence Zone, 68) |