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A MODEL OF CONSCIOUSNESS: AN ENGINEERING APPROACH

By

Emil Jovanov

e-mail: jovanov@ieee.org

Electrical and Computer Engineering Dept.
The University of Alabama in Huntsville
Huntsville, AL 35899

The Kingdom of Heaven is not a Place,
but a State of Mind

Abstract

Consciousness, as a complex phenomenon, arises on a hierarchy of human rhythms and their interaction with the environment. We present here a model of consciousness represented as a parallel distributed multiprocessing system with rhythmic scanning within a set of active modules. Dominant "gestalt" activity is then created by the global exchange of information on "system bus," and by means of a common electromagnetic field of brain waves. Module priority is dynamic and determined by an available time slot on the system bus; electric potential; and the module's metabolism (energy budget). The main system strategy could be defined as minimizing energy consumption. The limbic system has a crucial role, as the evolutionary role of module activation distracts stable mentation and stream of consciousness. The proposed model is used to analyze normal as well as possible states of expanded consciousness.

1. Introduction

At the present prime time of consciousness studies, the main mistake of many researchers is the expectation to resolve consciousness phenomena on a single level, either at the micro (atomic) or macro level (universe). We believe that consciousness exists as an eternal play on a hierarchy of processes, and that different states of consciousness represent only our ability to comprehend its complexity. The measure of consciousness is therefore the span of our awareness of this multitude of processes.

One possible approach to analysis could be to observe man as a complex system, and use engineering methods to analyze its performance. Normal human performance is reasonably well explained in different scientific disciplines. However, altered states of consciousness, as the most boundary phenomena, are indispensable for system identification and characterization [1]. Although human performance in the normal state of consciousness is amazing, its expansion during some altered states is really fascinating. How can it be possible to enormously increase processing performance? It is often reported that when our life is in danger, our possibility to analyze the situation, retrieve images, and other information becomes incomparable to our normal state. The crucial questions are what make this activation of hidden reserves happen, and is it possible to systematically improve one's performance?

The main problems facing the scientific investigation of these phenomena are poor reproducibility and the inadequacy of objective measures. What makes one meditation successful; can we rely on subjective report of the meditant; how can we judge a healer; and what is a successful healing session? How can we set weighting factors on any objective measure we get from our experiments? The transient nature of phenomena observed makes the results of statistical analysis even fuzzier.

Our interaction with the environment is usually omitted from exploration. Man's functions are very well adapted to changes in his environment. Although not crucial for basic functions, it should be carefully analyzed in the analysis of subtle phenomena. Our internal rhythms interact with external rhythms. The most important slow rhythm is the daily rhythm sensed directly as change of light. Rhythms connected with the daily rhythm are called circadian (an example is pineal gland melatonin secretion). Some experiments in the absence of natural light have shown that the basic human "clock" is actually slightly longer than one day, and closer to one lunar day (24h 50min) [2]. The lunar day has a similar period (24h 50min). On a slower scale, a strong influence on the Earth is its geomagnetic field, which is influenced by the following periods: the Moon's rotation (29.5 days); the Earth's rotation (365.25 days); Sun spots (11 and 22 years); the nutation cycle (18.6 years); the rotation of the planets (88 days to 247.7 years); and all the way out to the galaxy's rotation cycle (250 million years) [2].

Very important rhythms are in the order of 1-2 hours, like hormone extraction, and dominant nostril exchange [3]. In the range of human EEG, we have the Sun's electromagnetic oscillation of 10Hz [2], while the Earth-ionosphere system is resonant at frequencies in the theta, alpha, beta1 and beta2 bands (the so called Schumann resonances [4]). Different species often have internal generators of environmental rhythms, which can be extremely precise, up to 10-4 [5]. The frequency of these oscillators is then phase locked loop (PLL) synchronized with the natural rhythms. Environmental synchronization sources are often called "zeitgebers." The mechanism of optical synchronization is shown in [2, 6]. The presented rhythms should inspire a better understanding of the interaction of internal and external rhythms during specific states of consciousness.

At the present moment, the neurophysiological basis of consciousness is represented by a thalamocortical model with different modalities (as a reference, we advise reading the proceedings of the electronic symposium "Thalamocortical Foundations of Conscious Experience".

Crick first emphasized the importance of thalamocortical connections in 1984 [7]. He pointed out its remarkable position and connections. Most neurons have their dendrites spread around thalamus and "gate" access to the cortex, which makes possible the extensive exchange of information. LaBerge hypothesized that attention can be expressed as a relative increase of information flow on particular pathways against the others, emphasizing the possible role of thalamocortical structures in this process.

Baars developed the model of Global Workspace [8] (GW), in which the most active coalition of modules receives control over the GW. The most important part of this model represent ERTAS (Extended Reticular Thalamic System), which, in addition to RAS, emphasize the role of the thalamus and its projection to the cortex.

This paper introduces a model of conscious processing analogous to a distributed real-time multiprocessing system. Although primarily theoretical, this model also makes possible the simulation and analysis of altered states of consciousness.

2. Electromagnetic Activity of CNS

It may be reasonable to view the search for EEG correlates of subtle states of consciousness as being similar to the analysis of a modem signal which is transferring text between two computers. Although a spectral analysis of the modem signal will not reveal the nature of the story, a spectral analysis of a speaker's voice speaking this text may well do so. We believe that subtle states have their own EEG correlates, in much the same way as do gross neurophysiological states of consciousness. As an example, it has been reported that EEG correlates of a low concentration odors appear at lower concentration, even without being perceived.

Conscious processing has a very dynamic nature and includes a variety of spatio-temporal patterns of activity. William James wrote in 1890 about "stream of consciousness" and "centrality of attention." The rhythms of EM activity of CNS have evolved from epiphenomenon (during the 1950's, the EEG was considered as brain "noise") to correlates of successful cognitive tasks [9, 10]. The different frequencies of the brain's EM activity may represent different levels of hierarchical processing (see Jovanov [11]).

It is supposed that the integration of sensory information is performed by 40Hz scanning (synchronous oscillations) [7, 12]. MEG studies of cognitive tasks have proved the existence of impulse packets on 1000Hz, every 12.5ms. Even more important is the fact that consciousness of separate sensory information exists only if inter-stimulus time exceeds 13.7ms [12]. It is interesting to notice that some species of electric fish living in muddy waters "scan" its environment using continuos sinusoid of 50-1000Hz, or using impulses lasting 1ms on every 25ms (which is 40Hz) [5].

EM field perception for different animal species is well confirmed, but still has to be proved in man [5]. Possible mechanisms for this perception are outlined by Adey [9], and Rakovi? [4]. The excessive exposure to an EM field has been proved to distract the function of the pineal gland, and specifically, the mechanism of circadian rhythm control [13]. The possible role of magnetite crystals in brain tissue has still not been discovered. An open question is also the interaction of environmental EM fields and human brain rhythms, especially if we bear in mind their closely related frequency. It is logical to assume that these rhythms are developed as a response to changes in the environment, and a better understanding of the mechanism of interaction of internal and external rhythms may lead to an understanding of human subtle phenomena. Rakovi? has developed a biophysical model of altered states of consciousness based on these characteristics of the human environment [4].

3. Conscious Processing Model

This hypothetical model of consciousness as a real-time distributed, parallel, multiprocessing system with a common bus was developed having in mind the anatomy and physiology of the central nervous system (CNS).

The processing of distinct sensory signals is performed by a specific thalamocortical system [6], which consists of a functional unity of specific thalamic nuclei with projected cortex cells. This unit (or module) is represented in our model as a single processor on a common system bus. Some modules are dedicated (like audio, motor, visual, etc.) while others are general purpose or associative. A module is characterized by a processor (CPU); permanent memory represented by genetically inherited anatomic organization (ROM); temporary working memory (RAM); and local connections with neighboring modules. Associative modules carry dynamic pictures of working space that can be represented as successful copies of working programs or memorized experience.

In the case of an already experienced situation, these modules control the activity (automatic action), while in a new situation, modules have to intensively cooperate to modify existing (or create new) programs for this particular situation. On a neural level, learned experience is "hardwired" (static mapping) with established synaptic weights, while the new situation is resolved by simultaneous activation and synchronous activity of different regions (modules).

The Global exchange of information is accomplished by:

  • The exchange on the global system bus (neural transmission), and
  • By means of common EM field of brain waves.

The possible role of a system bus, according to the existing findings, may have a nucleus reticularis (NRT). The main issue in this case will be the control of the system bus and global exchange of information.

Global coordination should be performed on two levels:

  1. The detection of synchronous activity in different modules, and
  2. An information exchange between synchronous modules.

The first level is equivalent to the acquisition of information from the environment, and it is possibly realized using synchronous 40Hz oscillation [12]. It is important to emphasize that a system "gestalt" is formed 100-200ms after the stimulus; although analysis, cognitive processing and preparing of action goes on n the meantime. Having this in mind, Gray represented consciousness as an output of a comparator that compares an "inner plan of action" with an outer state [14].

Most models consider permanent requests for global workspace from different modules, and then grant it to the most active set of modules ("Winner Take All" neural network). However, in the proposed model control of a system bus, this is seen as a serial scan of set of active modules, where every module receives particular time to control the system bus (time slot). The scan clock is possibly an internal clock ("pacemaker") synchronized with some rhythm from the environment. For the sake of global synchronization, the EM rhythms of the Earth and Sun probably have a significant role. This function could be contributed to Intralaminar Nucleus (ILN formation) [12]. It has been shown that injury of this small group of neurons cancels the conscious state as well. This fact can perfectly fit in our model where lack of global synchronization breaks off global exchange of information, and therefore consciousness itself.

The global state of the system can be characterized by a set of active processes and processors (modules). Every processor has a dynamically given time slot on the system bus, when its local process becomes global. An active set of processes represents a set of uninhibited modules that access the system bus, or global workspace. The total system cycle is then given as the sum of individual time slots of active modules.

The change of module priority can be represented as a combination of the following mechanisms:

  1. An increase of available time slot on the system bus,
  2. A change of processing performance that can be realized as:
    • a local change of region potential (it can be seen as CNV potential for evoked responses or long term integral of module activity [9, 15, 16]), and
    • increased metabolism, supported with regional blood flow, and manifested as a slow-frequency EEG component [17, 18].

Different methods of functional brain imaging have shown that even when your attention flits, it flits to one thing at a time.

The default inherited modules bus priority is evolutionary, and developed as a set of priorities established to increase the probability of surviving. As a characteristic example, we can take an animal which, at a potentially dangerous sound, "becomes all ears," suspending all the other modules. As a consequence all the available energy budget is given to the sound processing modules, and its result is globally available.

Module activation increases local metabolism of the region. As a consequence, a part of ANS will be activated to support control of increased metabolism, which includes a number of biochemical and neural processes. All this activity further increases metabolism as well as overall activity in the region, acting as passive "noise" interfering with module output. Moreover, the activation of the limbic system itself decreases available system bus throughput, and increases energy consumption. We refer to this complex of problems as "metabolic noise".

Therefore, unlike computer systems, processing changes processing conditions, thereby retroactively influencing the process itself (stream of consciousness)!

Consequently, in a normal state you can not allow a large number of active modules. As an extreme case, clinical death represents an extreme decrease of metabolic noise, which allows for a very short time the super consciousness of subtle signals that are not available in the normal state. It can be the basis for an explanation of Near Death Experience phenomena.

The basic strategy of the system is defined as the minimization of energy consumption, and can be realized using the following mechanisms:

  • Decreasing system scan frequency,
  • Decreasing number of active modules, and
  • Decreasing energy consumption for individual modules.

We can find all these mechanisms in the dream state. A decreased mean EEG frequency may represent lower scan frequency. Fast spindles during sleep onset could be considered as the manifestation of "check out" procedures that take place to define the state of the system before the module is set to a low activity mode of operation. Then some senses are deactivated to decrease the number of active modules, and activity on specific modules is decreased to the level of possible recognition of dangerous situation. It can also be considered that during sleep, associative regions modify their model of reality according to previous experience. An improved model (and its effectiveness) is, of course, of great evolutionary value for all animal species.

A second characteristic state is meditation. It makes use of consciously decreased physical awareness, and therefore the decreased number of active modules. As a consequence, a decrease of scanning frequency is visible (which can be represented as a decreased mean EEG frequency [19, 20]). In addition, the decreased activity of physical awareness modules makes available additional energy within the existing energy budget. This energy could be used either to increase the activity of currently active modules or to activate additional set of associative modules.

During normal states of consciousness, associative modules make possible centralized control with minimal energy consumption. Modified or new situations further energize sensory and associative modules to modify an existing spatio-temporal pattern of activity. It is equivalent to the modification of an existing, memorized program. Automatic activity can also de-energize the nervous system to the sleepy slate (reduced wakefulness).

3.1. Role of Limbic System

In the proposed model, the limbic system is not just an ordinary module. Its role is crucial because of its influence on the vegetative nervous system. Evolutionary-wise, this function is of great importance, because it makes possible the high priority activation of a set of modules necessary for survival.

However, the same reaction takes place even in a case where the dangerous content is not real, but existing only as mental content. That will definitely change the "stream of consciousness" and the processing, itself. As we can not consciously control the function of the limbic system, we can not control the stream of our consciousness, either. This is the reason for the "wandering mind" that can not be stable on one particular point. Viewed in this light, we can understand Pata?jali's sutra ("yogah cittavrtti nirodhah") as a cessation of movements in the consciousness, or attaining stable flow of consciousness.

3.2. Toward Super-Consciousness State

What is the psycho-physiological basis of the super-consciousness state that characterizes some altered states of consciousness [1]? Based on the proposed model, we can analyze the following mechanisms:

  • Inhibition of sensory and motor modules which have no relevance to the current focus of attention. As an example, we can consider focusing on music, and having inhibited other senses and physical consciousness. Consequently, decreasing the flow of sensory information releases new energy within the available energy budget; decreases system bus overhead in favor of active processes; and decreases system metabolic noise.


  • Stable focus of attention independent of its content. The perpetuated effort to stabilize the focus of attention leads to the willingly regulated limbic system and a weakening of its feedback on the flow of consciousness. After that change, normal consciousness is not the "fighter for ends" anymore, while a new, extended, consciousness represents "detached observer" capable of observing his environment as it is. This leads towards "ultimate reality" [22], without the sympathetic burst of unsupervised ANS [23].


  • Stabilization of basic physiological rhythms and constituting consciously controlled center of physical consciousness. As a consequence, the global information exchange cycle is increased for an amount necessary to control these rhythms in a normal state, and metabolic noise becomes discrete instead of wide-band. It is shown that the stabilization of physiological rhythms stabilizes CNS rhythms, as well [20]. We can compare this effect as an effort to look at a far-away scene from a boat on a lake. If waves rocking the boat were irregular it would be very hard to concentrate. On the other hand, if waves are regular (no matter if they are large) it would be much easier to maintain a stable focus of attention. It could be considered that stable physiological rhythms could provide the foundation on which extended consciousness arises. It has been shown that insights objectively characterized as sudden and instantaneous are preceded by a characteristic pattern of brain electrical activity [24].


  • Decreased energy consumption. With stable consciousness, decreased energy consumption decreases metabolic noise, thereby bringing a greater awareness of subtle phenomena.

  • 4. Conclusion

    The proposed model offers an alternative view of conscious processing, and provides a theoretical framework for practical experiments. From this perspective, it looks like Rodin's sculpture "The Thinker" represents the wrong archetype. The intensive physical effort visible on this statute, would, in our model, increase overall metabolic noise and energy consumption; and thereby decrease the available time slot for conscious processing at a the higher level. Physical effort is useful only in association with a situation that requires the same effort. It is not strange, therefore, that a large number of great inventions are conceived during sleep, when metabolic noise is minimal, and motor and sensor areas are inactive.

    Many experiences of expanded consciousness are described as sudden and without obvious cause. They could be triggered by a simple sound or visual stimulation (flow of water, falling leaf, etc.). The missing link for those descriptions is a long period (usually 3-12 years) of preparation for that sudden moment of clear consciousness. During this prolonged period, we believe, a certain psycho-physiological base is being prepared for launching us to a higher state. The systematic investigation of that preparatory period, the associated changes on all hierarchical levels of human existence, and the practices supporting this kind of change, could bring us closer to the ultimate phenomenon of Being, True Consciousness.


    References

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    Copyright 1998, Emil Jovanov, All Rights Reserved

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