Another Remembered Present
February 1, 2012 | James Kohl
http://www.sciencemag.org/content/335/6067/415.short Subscription required to read the full text. Here is the introduction.
Intuition tells us that perceptual experience—the seamless flow of conscious images of vision, sound, touch, and so forth—reflects the external world. Accordingly, information flow along the brain’s sensory pathways has been thought to follow a caudo-rostral direction, away from the ports of entry, toward integrative cortices in the anterior parts of the frontal and temporal lobes. However, this view of a unidirectional, “bottom-up” processing cascade is challenged by findings which suggest that there is also information transfer in the opposite, “top-down” direction, from association areas toward early sensory cortices. A particularly intriguing observation is that while the initial bottom-up activation sweep along the sensory pathways can accomplish stimulus processing of considerable complexity and yield certain automated behaviors, conscious awareness of a sensory object appears to depend on top-down signals (1–3), as observed in the visual (4), auditory (5), and somatosensory (6) systems. Why is this the case?
Here is my comment: http://comments.sciencemag.org/content/335/6067/415
In my model of bottom up organization, self-engineered genetically predisposed intracellular interactions depend on chemical input from the environment, which activates existing intracellular interactions from the top down. The chemical input is associated with nutrition (food odors) and self/non-self recognition (social odors/pheromones) from microbes to man.
In this model, if olfactory/pheromonal input is responsible for the consciousness we do not attribute to other organisms, it would nevertheless be an evolved genetically predisposed attribution predicted by animal models of sensory stimuli and their unconscious affects. Of course the two essential unconscious affects are chemically associated with nutrition and reproduction because evolution could not have occurred if the unconscious affects of chemical stimuli did not lead to the proper choices.
Thus, the answer to the question of “Why would the conscious mind be grounded in dispositional records held in CDZs, rather than the “raw” version of reality initially established in the early sensory cortices through bottom-up signals from the thalamus?” is contained within the olfactory/pheromonal model. And Kasper Meyer nearly answered the question. “The brain “constantly and internally [generates] varieties of hypotheses and [tests] them upon the outside world, instead of having the environment impose (instruct) solutions directly upon the internal structure of the brain” because the plasticity of responses has been established along an evolutionary continuum that did not require consciousness or the thalamus for proper choice. But now that we can think about the choices we make, we think that consciousness is something other than what is required for food acquisition and reproduction in other species.
In my model, consciousness is an evolved function of how sensory input from the environment directly effects the mammalian gene, cell, tissue, organ, organ system pathway that links the input to the diversity of behaviors across species and within species (e.g., the behaviors linked directly to food choice and mate choice by olfactory/pheromonal input).