Conscious perception

This book adds to numerous preceding texts on consciousness the relatively new concept that particular neurotransmitters may be central to the process. As outlined in the Preface, communication between neurons is essential for consciousness and such communication, on the timescale applicable to conscious perception, is principally mediated by chemical neurotransmission. As Susan Greenfield (2000) points out in The Private Life of the Brain , acetylcholine may enable a whole population of cells to become more important than individual units, a kind of neuroscientific Marxism If the concept of transmitter NCC is incorporated into future discussions of the neurobiology of consciousness, or adds a further dimension to the neuropharmacology of disorders of the brain which affect conscious awareness, this book will have more than served its purpose. 

The most constant internal experience in my salvinorin journeys is a drastic shift in my sense of identity and conscious perception. At the onset of the experience my identity is completely dislodged from my body and familiar self. Following this I experience myself as existing, but not as a body, human, or personality. I usually find myself in some alternate dimension, which can either closely resemble earth, or be entirely alien. Quite often the worlds visited under the influence of salvinorin do not obey the laws of physics which we are typically accustomed to. The action of the forces of gravity and momentum, the dimension of time, and the geometric construction of these worlds, can be rather bizarre. 

An alternative explanation for these higher thresholds was not that they took greater stimulus intensity (longer flashes) to perceive but that the social unacceptability of the words made the subjects more reluctant to voice them until they were quite certain. Further research showed that this accounts for part of the delay, but there is still a perceptual defense factor. More direct evidence for perceptual defense comes from the fact that physiological reactions associated with emotions, like quick changes in the electrical resistance of the skin, can sometimes be seen when emotionally threatening words are presented that are well below a subject s conscious perception threshold. 

Psychologists concluded that there are three stages in perception. There is first an initial perception/recognition outside of consciousness. This is followed by a stage involving discrimination of the potential emotional threat of the stimulus. If the stimulus is classified as threatening at this second stage, an influence is exerted on the mind to raise its threshold for the third step of the process, conscious perception of the stimulus. 

With the development of the human brain, a functional network with over 100 billion interrelated nerve cells and 1010 bit capacity arose. With this system, whose operation is inseparably connected to conscious perception, life on earth reached its most sophisticated form. Furthermore, the human being, who is primarily a social creature, is a building block in the creation of a gigantic product human society. The function and capacity of society obviously exceeds the sum of the activity of its members. Based on the practically inexhaustible capacity of the human brain to acquire drives, human society represents a qualitatively new, higher form of life. For example, a country, presently the most sophisticated form of a human community, consists of millions or even over a billion humans and operates de facto as a huge living complex interacting with other similar entities, about 200 at present. 

In my case the decisive period of experimentation that built into my brain the urge to clarify the unknown neurochemical mechanism of the acquisition of a drive fell between 1951 and 1953. After 50 years of continuous analysis of this problem, it has become my firm belief that the mammalian brain reached its highest level of organization with the evolution of specific cortical enhancer regulation enabling it to acquire drives. I also propose that this development culminated in the appearance of the Homo sapiens, the only mammalian species whose fife is primarily based on the acquisition of unnatural drives. It seems to me that just as the discovery of the force of mutual attraction among all bodies led to a sound interpretation of the world around us, the discovery of the force of mutual attraction between cortical neurons will lead to a sound interpretation of a brain function which is inseparable from conscious perception. 

Tibet performed a series of experiments on fully conscious patients during the exposure of a cerebral hemisphere for some neurosurgical procedure. The postcentral gyrus was electrically stimulated with extreme care in order to establish the conscious perception of this stimulation. 

Libetfound that a single stimulus was ineffective. For the conscious perception of cortical stimulation he needed to apply trains of 0.5-ms pulses at liminal intensity for as long as 0.5-s duration. 

Thus Tibet has detected experimentally in humans the phenomenon we observed in rats and described as warming up. He just did not know what happened. He obviously activated, with the aid of electrical stimulation, a chain of ICRs and ecphorized the engram as an integral whole. He needed 0.5 s until the cooperating neurons were brought to the state of excitability inseparable from conscious perception. 

We assume that the phenomenon of forgetting and remembering is attributed to the continuously changing excitability of the cortical neurons, due to the physiological undulation in the synthesis of the specific enhancer substance. The operation of this mechanism always makes it unpredictable which group of neurons - in the course of the explosive activation of a chain of ICRs - will be temporarily unable to reach the level of excitability needed for conscious perception. 

Proper stimulation of the cooperating neurons as an integral whole allows the ecphorization of the fixed information at any later point in time. This is inseparable from conscious perception thus, the past experience is vividly relived in a cognitive and affective manner. 

According to our working hypothesis (see Sect. 3.4.2), a chain of ICRs is ecphorized as follows. The proper stimulus activates the first member of the chain. Activation means that a higher amount of the neuron-specific enhancer substance is synthesized and the excitability of a mass of cortical neurons is enhanced. The members of the chain are thereafter explosively activated in the sequence in which they were fixed during the learning process. Activation of the chain of ICRs as an integral whole is inseparable from conscious perception and from the proper affective state of consciousness. 

With the development of the human brain, a functional network with over 100 billion interrelated nerve cells and 1010 bit capacity arose. With this system, from the operation of which conscious perception is inseparable, life on earth reached its most sophisticated form of appearance. Furthermore, the... 

Thus, (a) whenever a chain of ICRs is fixed in the human brain, the proper cortical neurons remain, on an unconscious level, constantly active for life, and (b) if the proper method is used, even a chain of ICRs that had never been ecphorized after fixation can be activated to the level needed for conscious perception at any later date. The recalling of any chain of ICRs is necessarily inseparable from an affective state of consciousness, due to the emotions coupled as appurtenances to the cortical neurons when they learned to cooperate with each other. Freud developed empirically sound methods for ecphorizing forgotten chains of ICRs in humans, decades after their fixation. 

The time delay between sensory signaling and the subjective conscious perception of sensation which has so carefully been demonstrated by neurosurgeon Benjamin Li bet and other experimenters may also have a simpler explanation than those proposed so far. Li bet and others have shown that a pin-prick of the finger, for example, transmits a signal to the cortex of the brain via the thalamus, which arrives in a few thousandths of a second. All sensory signaling except olfaction is similarly transmitted first to the thalamus which acts as a sort of relay-station distributing the signals to the appropriate domains of the cortex. Yet conscious perception of the pin-prick can by various experimental techniques be shown to be delayed by up to a half-second, while "cerebral neuronal adequacy" is achieved. 

The third component of the physiological effect involves the sensory impact of the cough medicine. If the medicine could be administered without any sensory impact, i.e. without the patient perceiving that any treatment had been administered, then it is doubtful that there could be any true placebo effect as this is dependent on the conscious perception that a treatment has been administered. Consciousness... 

Performance is said to be at either a skill-based or a rule-based level when tasks are routine in nature. Skill-based performance involves the smooth, automatic flow of actions without conscious decision points. As such, skill-based performance describes the decisions made by highly trained operators performing familiar tasks. Rule-based performance involves the conscious perception of environmental cues, which trigger the application of rules learned on the basis of experience. As such, rule-based performance corresponds closely to recognition-primed decisions (Klein 1989). The... 

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