Change of Paradigms in Consciousness Research

About it...: New Ideas in Consciousness Research

At least initially, consciousness expresses itself exclusively in the language of sense qualities, i.e., of light, colors, sounds, scents, pleasure, pain, and their derivatives. As a rule, sense qualities are viewed as a product of consciousness.

The diametrically opposite standpoint is advocated by Rudolf Hernegger in his most recent book, "Perception and Consciousness. A Contribution to the Discussion in the Neurosciences" (Spektrum Akademischer Verlag, 552pages). According to Hernegger, the brain receives information about the environment from the sensory system in the form of sense qualities. Instead of sense qualities arising from consciousness, he contends, the reverse holds true: Consciousness arises from the so-called nonspecific reticulo-thalamo-cortical activation or attention system and is based on sensation and perception of sense qualities.

Hernegger's first argument is based on the fact that even insects react to sense qualities such as light, color, sounds, and scents. Karl von Frisch, in his experiments with bees, proved that those insects, instead of reacting to specific electromagnetic wavelengths, i.e., to physical stimuli, actually respond to colors: Bees trained to fly to a certain color when seeking food flew to dishes of that color even when lighting conditions were varied, i.e., the wavelengths were changed. Similarly, it has been shown that flies, for example, respond to lightness and darkness. The phenomenal world of colors, flowers, sounds, and scents, which has arisen from the interaction between insects and plants, indicates that insects and other invertebrates can grasp sense qualities without a cognitive function being involved. Sense qualities are a product of the sensory system and its interactions with physical stimuli, and were developed long before the cortex, that indispensible organ of consciousness. Therefore, they cannot possibly be a product of consciousness; phylogenetically, they must have preceded consciousness and the cortical network.

Sense qualities are a completely new form of information, a product of the interaction of sensory systems with the environment: Unlike metabolic organs, which are able transmit physical matter into the organism, sensory systems can transmit only information about the stimulus. This information, which is generated by the sensory system as sense qualities, is a representation or a symbol of the physical properties of the stimulus. First, the sensory systems devise filters, which serve to select from among the stimuli. As evolution progressed, these filters became better and better adapted to the biological needs of the organism. For the organisms, recognition of food sources and enemies under conditions of changing light, i.e., changing physical stimuli, was crucial to survival. In other words, color constancy and formation of invariants determined the development of sensory information that went beyond representing only a simple physical stimulus and became capable of expressing relationships and combinations of stimuli, which is actually the case with sense qualities. Rather than filtering simple physical stimuli, sensory systems respond to attuned sets of stimulus conditions by development of sense qualities, which are then projected onto the environmental stimulus in such a way that the organism is able to recognize the stimulus through the filter.

Sense qualities were thus the most influential factor in development of the cortex. The cortex resulted from the interaction between the sensory filters of the sensory system and their products, the sensory qualities, for which it serves as a receiver, processor, and storage unit. Sense qualities must have influenced the origin and function of the cortical network, as they existed long beforehand and served as the cortical receivers.

In order to substantiate the learning capabilities of artificial networks, network theorists have introduced a ºteacherº to tell the network whether a chance linkage between layers, nodes, and neurons is closer to or further away from a certain solution; correspondingly, linkages are weighted as better or worse, and the better ones get reinforced. In the development of the cortical network, sense qualities assume the teacher's role, i.e., the better they are represented by the cortical network, the likelier it is that certain linkage patterns will be selected. In the course of billions of attempts, nature has had ample opportunity to develop a cortical network which is completely dedicated and adapted to the task of receiving and representing sense qualities. In this fashion, the cortex became the receiver of sensory information.

The genes determine only the receiver as an instrument, but not the information itself. Proof of this lies in the fact that no amount of electrical stimulation will arouse sensations in the neurons in the cortical sensory fields of individuals who are blind or deaf from birth, although equivalent stimulation in individuals with visual or acoustical experience elicits the appropriate sensation. Thus, colors, light, sounds, scents, and sensations of taste must first be generated by the direct confrontation of the sensory receptor with a physical stimulus; sensations produced in this fashion can be stored.

The transfer of sensory information from the periphery to the cortical representations involves several steps:

  1. First, cortical sensory detectors must be formed in the sensory cortex in response to a unconscious sensation.
  2. In the process, the internal or external stimulus causes the organism to enter a state of activity or preparedness, in which it is able to orient its body and senses actively and selectively toward the stimulus.
  3. Sensation or perception occurs when the sense qualities, which are encoded in the neural code of the sensory detectors, are decoded when the sensory receptors meet the physical stimulus.
  4. When the sensory receptors meet the physical stimulus, the cortical representations of the information are compared with the sense qualities that are projected onto the stimulus by the sensory system. If they fit as lock and key, the centrifugal and centripetal flows of excitation conjoin to form a feedback loop, so that the peripheral event is synchronously represented in the cortex, and attention transforms the sensory system into a receiver organ for sense qualities. This sensory process is regulated by the nonspecific excitation of the central activation system, which simultaneously forms the attention system and represents and involves the organism as a whole.
  5. Attention in this sense refers to active behavior of the whole organism that is oriented toward the stimulus and coupled by a feedback loop involving superliminal arousal of excitation of both individual neural systems and local cell assemblies, which transmit and process sense qualities. In this way, sense qualities become language elements in which consciousness is able to express itself even before the development of human language.

The whole text you find here:

The Author:

R. Hernegger

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