Monitors: key mechanisms and roles in the development and aging of the consciousness and self.
A network of interacting neural structures, called monitors, exists in the mammalian brain in which data derived from sensory inputs and from memory stores is precisely displayed within the brain. The key function of monitors is to provide an 'ultimate monitor', proposed to be the locus that generates the phenomenon of conscious self awareness, with information that defines or maps the positions of the parts of an individual with respect to each other and with respect to external objects or events at specific times. The resolution of at least some of these monitors (e.g. some concerned with vision) is extremely great and approaches, in the case of vision, the precision with which images of external objects are projected onto the retina. This conclusion is based on the fact that an individual is able to perceive visual images with an acuity that closely approximates the fineness of resolution of the retinal image. The sensory signals that provide information about body part positions and those that provide information about the exterior are evidently integrated with each other in a suitable hierarchy of monitors so as to provide a coherent representation of self-vs.-environment. The logical 'framework' monitor for this integrated display-mapping is proposed to be that that maps the body in space and it is proposed that the locations of objects perceived through the touch sense and senses that deal with more remote items in the environment become superimposed on a map that extends or extrapolates the body space map beyond the body's physical boundaries, a learning process that occurs during development. The ultimate monitor not only receives a display of the synthetic representations derived currently through the integrative functions defined above, but also is provided with at least four other inputs from other different classes of monitors. One of these is a monitoring system that generates timing signals needed to separate inputs into a time order and to assign an order to them. It is proposed that it is awareness of these timing signals by the ultimate monitor that is the essential and indispensible input that generates the phenomenon of awareness. A second input to the monitor that is the self is a selected part of its own activities. This awareness of what the ultimate monitor is receiving, doing or planning to do in the future is the characteristic necessary for awareness of self.(ABSTRACT TRUNCATED AT 400 WORDS)
Strehler
B L
BL
University of Southern California, Los Angeles 90089-1481.
D000375:Aging / Q000502:physiology*; D001364:Awareness; D003243:Consciousness / Q000502:physiology*; D004532:Ego; D006801:Humans; D009430:Neural Analyzers / Q000502:physiology*