On Sun, 9/9/12, clarence sonny williams wrote: “There are distinct and independently-operating anatomical regions in the brain that are integrated (sometimes tightly and other times more loosely), such as the visual system, etc.”
My comment: There are no distinct and independently-operating anatomical regions in the brain. There are separate visual pathways projecting from each of ~ 20 anatomically distinct classes of the ganglion cell, and the retina contains ~ 80 different cell populations. That’s why researchers argue that the linear pathway model of cortical visual processing is fundamentally unsound. Instead, it should be clear that only a multidimensional view can resolve the issues created by attempts to pigeon-hole development of species-specific behaviors into any framework that involves domain-specific modules that have neither been identified, nor even accurately conceptualized in the context of established neuroscientific facts, which currently provide the framework for future investigations (e.g., across species).
Many of these investigations might already be complete if not for the amateur evolutionary theorists, like Williams, and the ethologists who attempt to discuss sensory cause and effect as if a direct epigenetic link to genetic predisposition and behavioral affect was not an absolute requirement. Inventing domain-specific modules, for example, is merely a means to clearly state that theorist/inventors do not understand the basic principles of biology and levels of biological organization that enable adaptive evolution via ecological, social, neurogenic, and socio-cognitive niche construction.
Positing that avian species are primarily audio-visual before examining their olfactory acuity and specificity in the context of adaptive evolution is another sure-fire way to lead others astray. This does not mean that ethologists should question evolutionary theorists about domain-specific modules, however. It means that an interdisciplinary approach must be adopted at the same time past biases are abandoned.
That interdisciplinary approach has already been adopted by most neuroscientists who currently are not even involving themselves in discussion of theories about behavioral development due to different sensory modalities, since it is widely known that the brain integrates sensory input via classically conditioned effects of olfactory/pheromonal input on genes in cells of hormone-secreting tissue impacted by ~10,000 neurons in 26 different brain areas, and that same hormone-secreting brain tissue transmits signals to ~ 30,000 or more neurons in 34 brain areas.
What then can be said about operant conditioning (“animal training”) involving pain receptors, and claims that avian species are primarily visual creatures, or that any animal has an evolved domain-specific module? Nothing!
What makes the “modular concept” useless is that there is no evidence for the evolution of domain specific modules.
Neuroscientists are not simply calling domain-specific modules something else, they’re using terms like “layered,” “the triune brain,” or a “nested hierarchy” to indicate interconnectivity because there is no evidence for evolved domain specific modules in any species.
The visual system does not exist in microbial species, so if microbes were involved in our evolution, there is a question of why and when integration of the visual system occurred.
There are people who claim ongoing dispute when no dispute exists.
The data in the 30 publications from ENCODE (last week) should lead all but the most ignorant to dismiss concepts like domain specific modules. See also: Evolution Did Not Snap the Brain Together like LEGOS By Gary Stix | August 29, 2012 |