The Mind II AGI architecture Alan Grimes Abstract The following is an outline of a practical approach towards developing and refining a generally intelligent technology called Mind II. My purpose here is to describe the Mind II approach to AI, to present a rationalle for its fesability, and to outline the steps needed to realize it. The Mind II approach to AI is a cybernetic system derived from the Celular Automaton abstract machine. CONTENTS Introduction Motivation The Mind II approach. - Mind II is a cybernetic approach. - Design methodology Rationale The development process. - Phase 1: basic control model: The flatworm. - Phase 2: Elementary behaviors: The fish - Phase 3: Fundamentals of environmental awareness: The lizard - Phase 4: Basic cognition: The rat. - Phase 5: Epesodic memory and planning: The monkey. - Phase 6: Language and abstract cognition: Man An artificial evolutionary context for the refinement of AI design. - A VR environment as a learning tool. - A VR interface for user-AI interraction. - A VR environment as an evolutionary context. - The mechanics of evolving a Mind II AI. - Exploiting evolutionary theory. A Comparison to Other AI Efforts Commercialization. - Accelerating the evolutionary process by making the software available to home users. - AI as a stand-alone product. - Hardware accelerators for Mind II AI systems as commercial products. - Robotic systems. Introduction The Mind II architecture is my proposal for developing an artificial intelligent consciousness. It's name is derived from a classification scheme which I use to describe intelligent objects. The first class is the unmodified or weakly modified human brain, or Brain I. A biological variant of that design with significant anatomical and physiological changes is termed by this classificiation scheme as Brain II. The Mind type of AI is based on the neural organization of the brain but in the form of computer software. A mind I AI is based on a detailed simulation of organic neurons. It is highly likley that it is a feasable design but it is not likley to be efficient enough to be workable in a commercially viable product. It is also very likley that a design which uses a more abstract approach to creating a functional equivalent to the brain will yield much greater performance on the same hardware. Mind II aims to be such a design. Motivation The principal reason for working towards Mind II, or any general AI is the immense benefit to humanity that can be expected from a successful design. These benefits range from a better understanding of human cognition through a working experamental model to having a practical, useful AI technology which can be applied to any of a wide variety of problems. A listing of all the potential categories of applications would not be relevant to the present discussion. The second major motive which plays a large part in the Mind II approach steams from the risks to human interests associated with strong AI. These risks range from the minor risk from the possibility that an intelligent robot could go on a crime spree in down town Detroit to apocalyptic scenereos on a cosmic scale. The design of Mind II very deliberately stays close to the pattern of development which lead to human consciousness so that this risk may be mitigated. Firstly, the architecture will begin with a great deal of commonality with it's human model so that it is unlikley that it will demonstrate any faculties that humans might have difficulty dealing with. Secondly, by adhering to a biologically inspired model, it is hoped that a large portion of the many techniques used in human psychology, including the innate intuitive understanding of mind, may be successfuly applied to a Mind II based AI. The third area of risk in any AI venture is the risk that the project will fail. History gives us many examples of failed attempts to build a thinking machine. The Mind II architecture addresses this problem by staying close to the biological archetype. It is beleived that by not getting too "creative" by adding any "computer like" features such as direct number crunching and ascii-based text processing the core problems can be addressed and overcome. The downside to this strategy is that the resultant AI may lack many features and capabilities that would otherwise be possible. This approach is necessary to increase the chance the project will succede in creating general intelligence at all. Enhancements to the basic design can be explored in subsequent projects. The Mind II approach. - Mind II is a cybernetic approach. In studying intelligence and it's role in the human it becomes clear that it is hardly meaningful at all without an environment to interact with. Mind II, as a brain inspired approach, is grounded in a cybernetic theory. Beyond that it is clear that many types of learning require an active exploration of the environment such as procedural learning through trial and error. It can be concluded that without active learning the knowledge available to an AI is severely limited. Many previous AI projects reflect an assumption that this interaction is not necessary. Needless to say, none of those have succeded in producing a full AI. - Design methodology The essence of the Mind II approach is that it mimics the brain but completely disregards the fact that it is constructed with neurons. Wherever the computation preformed by the brain is known, the best available algorithm for performing the same job will be used. Where the algorithm is unknown a stand-in will be used and configured to match our best guess of it's information flows and to mimic all known connections with other modules. In the case of the cortex, an advanced hexaginal-latice celular automaton will be used to mimic the function of cortical columns. Current Celular automata models are theoretical in nature. They are specified by a state, a set of rules, and their interractions with their immediate neighbors. As such, they are not especially practical because it takes quite a while for a signal to propagate across a large latice. The brain solves this problem by using a complex topology where certain cells are able to send signals directly to cells in remote locations, greatly increasing the system's reaction speed. In most areas of the cerebral cortex six anatomical layers have been identified, these layers appear to have fairly distinct functions. The first attempt at the Mind II design will implement a "best guess" for all of them. One of the most interesting features of the brain is it's ability to re-task cortical columns on the basis of computational demands. Mimicing this function algorithmicly poses an interesting problem. One possible approach is to attempt to measure the workload of a each cell and make a rule for re-directing connections from highly utilized cells to neighboring cells that are not as heavily stimulated. Rationale It is reasnoable to expect that the Mind II architecture will succede in producing a general intelligence because it is based on a celular automata. Even though the educated guess that the cerebral cortex is basically a type of celular automata may be completely false the approach still has a high probability of success through the Church-Turing thesis. Because many types of celular automata are known to be a universal computers it is therefore highly plausable that a celular automata that can emulate the cerebral cortex. The only assumption being made here is that the Church-Turing thesis holds in the case of the cerebral cortex. The C-T thesis has stood for around 65 years so that is highly unlikley at this juncture. The design of the Mind II architecture is also strongly motovated by the possibility that there are certain critical aspects of the brain which we do not understand at all. Prior attempts at AI have depended on the programmer accurately determining what types of computations the brain does and then emulating them in the machine. Mind II, on the other hand, lies right on the border between emulation and simulation. On the level of details, it is an emulation, and on the systems level it is a simulation. It is hoped that by adhering to the form of the human mind that all qualities necessary for intelligence will be included, or notably absent, even if the programmer is not fully aware of what they are. I say it is good that some features of Mind II might be notably absent precicely because the exact nature of their absense will, itself, serve as a means for their discovery and inclusion. Because the workings of Mind II will be so similar to the brain, the description of missing functionalities can be made with sufficient detail as to be useful in their creation and inclusion in the next prototype. The development process. The most reliable strategy for developing a Mind II architecture is to re-trace the course of the evolution of man. This approach demonstrates a working implementation of each of the respective layers of functionality in the brain. It may be necessary, at times, to backtrack to earlier phases as deficiencies of the implementation strategy are uncovered. - Phase 1: basic control model: The flatworm. The earliest phase of our evolutionary development is the flatworm. It is a primative creature with a very simple nervous system which demonstrates little more than reflexive behavior. The goal of this level of development is to demonstrate a capacity to respond to an environment in a simple manner. A secondary task is to refine the programming techniques used to implement this functionality. This choice has a strong effect on the patterns used in the higher levels. The actual animal model may be any type of worm progressing towards more advanced kinds. - Phase 2: Elementary behaviors: The fish The next level is to implement sequential behaviors that allow the animal to respond to the environment in a patterned manner. It does this by both state-based controll and by either inhibiting or exciting the basic reflex behaviors. I would suggest that a quadripedal model be used for this phase. - Phase 3: Fundamentals of environmental awareness: The lizard Using the same animal model, the next evolutionary step is to include a basic memory. It's basic function is to generate maps of relationships between specific stimuli. This allows for the organism to organize behaviors with regards to the geography of a specific environment. The same mechanism is also forms the basis of epesodic memory. The system should be tested untill it can be shown to exhibt similar behaviors to a lizard. - Phase 4: Basic cognition: The rat. The rat is probably the most well-studied creature in the universe. One would be tempted to begin the project with the rat instead of "wasting time and money" in working up through the evolutionary heirarchy from the beginning. The purpose, however, is to establish a design pattern and good coding practices that will serve to organize and clarify the organization of the design and keep it in tune with it's biological counterpart. The testing at this point will be more extensive because so much is known about what the capabilities of a rat brain are. Specificly these are the ability to be able to acquire a world model which can be used not just to map out a known territory but to make predictions about a new teritory based on remembered knowledge. Instead of simply selecting among innate behaviors, the same type of automata should be able to learn completely new behaviors. If a working approach is developed it is very likley that it will be very close to the algorithm required for high level cognition. Infact, the bulk of changes from this point will be to adding complexity to the system by increasing the cortical area and increasing the complexity of it's topology. - Phase 5: Epesodic memory and planning: The monkey. The next major evolutionary improvment is the addition of the epesodic memory. This allows the system to remember not just places but events in it's past. Successful completion of this phase will yield a mind on a par with the chipanze. The body of the animal should be changed to a roughly humanoid bipedal design with some approximation of a hand maniplator although the precice physics are probably not necessary. - Phase 6: Language and abstract cognition: Man Far far from finally except for this brief document, there is human equivalency. The topolgy of the mind is expanded once again to include regions for associating symbols with internal representations. This, combined with all of the previous steps, should be enough for the mind to use language and think like a human being. An artificial evolutionary context for the refinement of AI design. Because intelligence can't form in a vacuum, a virtual world must be provided to provide the AI the stimulation and feedback it requires to acquire knowledge. Such a virtual world can serve three major purposes in the AI development effort. Those are that of a learning tool, that of a medium for user-AI interraction and as an evolutionary context for refining the Mind II design. To serve these purposes it is necessary that the virtual world have certain qualities. - A VR environment as a learning tool. A successful environment will provide many options for complex interractions. It should provide, to the AI, a rich array of auditory, visual, gustatory, and tactile feedback. It should have a robust and consistient physics. All objects should have predictable behaviors and these behaviors should have no arbitrary limitations. The environment should provide "raw materials" with which the AI can construct artifacts which may have useful properties depending on how well they were designed. The classic toys and games, such as chess, should be available as artifacts within the VR world. The actual "resolution" of the environment is not especially important but rather that it be possible to deduce the function of an object from it's graphical representation. - A VR interface for user-AI interraction. Human researchers and other users should have two forms of interraction with the world, both are of great importance. The first is the G0D-mode interface where the user sees a top-down (or other appropriate view) of the world and is able to adjust various objects in the system in arbitrary ways. This interface should also privide a way to inspect, edit, remove, or insert the artificial lifeforms. The other means for interraction is through a human-controlled VR avatar. The "front end" of this system should be symetrical with what is provided to the AI. It will connect to the VR through an avatar that is identical to the ones used for the AI. This is so that the human can directly debug the avatar software and so that the VR system's function as a medium for communication is not compromized because the AI only sees dots in space where the human is shown a top of the line 3D animation. The avatar interface should provide the user with the ability to interact socially with the AI entities. An AI development workstation may provide both of these interfaces simultaneously on different monitors. - A VR environment as an evolutionary context. It can be expected that the team implementing this plan may run into difficulties with the performance of their CAM rules or the overall topology of the mind. This problem can be addressed with an evolutionary approach. At first the environment will have to be very tolerant of the minimial capabilities of the AI model, a paradise if you will. The paradise zone will have a relatively high rate of resource replenishment, no requirements for shelter, and very few dangers. It's only evolutionary value will be to train the agents in the basics of food gathering and to protect their eggs (instead of eat them or allow them to be eaten). As the population increases the resources will run out and expansion will be necessary. The adjacent habitats will be somewhat hostile, shelter will be required for sleeping and protecting eggs. Food will be relatively scarce but agriculture will be supported. There may be engineering problems, such as building a boat or a bridge, required to move further along. There may also be periodic disasters requiring planning in order to achieve optimal utilization of the area. The next region will be extremely harsh, akin to a desert or an arctic tundra. Only by scouting and then making preparations will the creatures be able to make any use of this area at all. Beyond this area will be a challenge zone. A task such as building a complex machine from materials available in raw form in locations scattered across the entire world. Success will give access to another paradise zone, completing more difficult variants of the task will provide rewards to the creature such as increased strength, extended reproductive life, decreased metabolic needs, a number of instant clones, or any other advantageous gift. In this last zone, at the end of the world, there should be a "trial zone". This will begin with a tower on a tall mountain, a mountain so tall that only the most determined, and best prepared, creature will be able to reach it. Inside there will be a series of IQ tests for spatial, mathematic, and reasoning skills. Once a test is passed the creature can move on to the next. The biological modeling can be suspended in this zone so that the creature can take as much time as it needs. If it gives up, it can use a transporter to go back to the foot of the mountain where it will have to re-supply before it can make another attempt. The last of these trials will be the turing test administered through an avatar controlled by one of the experamentors. If the creature passes this it becomes immortal and invulnerable. It also gains access to a room within which it can control the rest of the world and use the full power of the software for self-modification -- it has won the game. - The mechanics of evolving a Mind II AI. The avatar models will be similar in nature to the ones used in the software toy "Creatures". The avatars will have to have biologically plausable requirements for food and a limited tolerance to environmental extremes and traumatic injury. All avatars will have identical physical capabilities and needs. These will include a base metabolic rate and an activity dependant rate. Each will have a "genome" which will consist of the program used to specify it's brain and how fast it runs relative to the rest of the simulation. This rate combined with the total size of it's cortex will determine it's brain's metabolic requirements. Also encoded in these genes will be information about it's coloring and pattern so that each creature will have a recognisably unique appearance. The lifecycle of the creature will have to be fairly long in order to make sure that it encounters enough interesting challenges during it's life in order to have an evolutionary impact. It would probably be useful too for it to have an egg phase so that it will have to evolve to protect it's eggs. The eggs will also be colored and patterned based on the genes so that it is possible for a creature to determine which eggs are it's own. Unlike the game Creatures, there will not be any classes of creatures. Any avatar can be used for any type of lifestyle from agrarian to canabalism. Various things in the game can be used as weapons. This might be unplesant to the creatures but it is necessary to promote their ability to think strategicly, work towards objectives, and deal with other minds. - Exploiting evolutionary theory. To accelerate the evolutionary process several steps can be taken. Firstly, the relatively short lifespan of the creature increases the number of generations that can take place in a short period of time. The limiting factor is that that the creatures need a significant ammount of interraction with the world in order to demonstrate a real intelectual capacity. Another approach is to use a faster computer as the simulator in order to compress the clock time each generation requires with minimal impact on the quality of it's experience. Population dynamics can also play a role. By periodically closing travel between areas populations can be limited to a size where they evolve rapidly away from the baseline. A pattern can then be established where the simulation runs for ten or fifteen generations as isolated units at which point the gates are opened for a period of two to five generations followed by another period of isolation. During the period of free travel, the populations can mix and traits which evolved during the isolation can spread to the broader population. Finally, programmers can examine all the creatures for desirable traits and then attempt to manually produce a winning design. Complexity analysis It is assumed that the dominant source of computational complexity in this model will indeed be the emulation of the cortex. It is further assumed that signals within this cortex will not have to propagate across a distance greater than a single bordman's area. Furthermore it is assumed that a propagation of this distance will be required at a rate proportional to the apparent step-rate of the human mind which appears to be around 18 cycles per second under normal levels of arousal. Humans appear to have a throttling mechanism that causes their brains to accererate to handle stressful situations and slow down when in a relaxed state, presumably to conserve energy. It is not beleived that this function is critical to producing a demonstration of functional intelligence though such functionality would likley to be of great use in mobile platforms for the same reason similar features are common in today's laptop computers. The computation to complete one update cycle of a hexagonal celular automaton is proportional to the number of cells times the distance between the edges of the latice which is proportional to the cube root of the number of cells. O(N * (3û)N) While the actual compute time required for each cell is unknown it is known that it will complete in essentially constant time because it will be a non-looping, non-recursive function of the previous state combined with the eight input channels representing the neighboring cells, a link to a topologicly remote cell in the cortex and a system-wide input. The input and output channels will be an ordered set of bits of a size yet to be determined. Under these assumptions it is possible to conclude that if the efficiency of the Mind II design can be made proportional to that of the brain, which has approximately four million CAM-like cells divided up into dozens of regions, then a machine capable of sustaining 350 billion operations per second should be sufficient to implement Mind II. A Computer System for Mind II development I beleive that it is possible to implement Mind II and the evolutionary system proposed above with today's hardware or, at the very most, hardware that can be expected to be on the market within the next few years. A distributed platform for this effort will probably follow the following outline. Each individual instance of Mind II will function on a discrete system based on a comodity platform. It will accept state information from a world severer, generate a 3D image of the world, process it, and then send commands to the avatar which resides on the server. In addition to the host processor a comodity 3D video processor will be used for generating the 3D scene and the bulk of the Mind II processing work will be accomplished by an array processor board inserted into one of the expansion slots. The total cost for each unit, at today's pricing, will be on the order of $10,000. A suitable evolutionary population of 200 can therefore be sustained on hardware costing around $2,000,000. Each Mind II system will be connected, via a simple network connection, to a host machine that will simulate it's world. Each area, as described above, may reside on a seperate machine. A suitable platform may be obtained for $15,000. I expect ten of these world-servers will be desired. The total cost of the hardware for this venture, including a few workstations and network infrastructure will be in the neighborhood of $2.25M A Comparison to Other AI Efforts A review of the literature will clearly show that very few of the ideas presented here are new. There are indeed a number of research efforts by people who actually have accademic credentials that, superficially, would appear to incorporate the key ideas of this proposal. I do not beleive that this is the case. I will here present a review of the most visable of these efforts and what I believe to be their flaws. One of the most prominent proponents of a Celular Automata based approach to AI is Dr. Hugo DeGaris. His approach, in my classification scheme, is a Mind-I design. He uses CAM as a medium for simulating organic neurons. He hopes that the rules he selects will succede in replicating the functionality of the cortex. While his approach might break new ground for neural-net approaches it is unlikley to succede in producing a pracitcal mind. The first major drawback to his approach is that it doesn't provide a general purpose memory as the Mind II does. His current approach of evolving neural modules and then wiring them togeather is unlikley to produce a capacity for introspection because the basic cognitive units aren't discrete. While his design will likley be able to solve a number of problems that involve a direct chain of cognition, it is unlikley to be able to exhibit directed cognition or the ability to construct and use representation of the environment. Assuming he did produce a workable model of the Cortex and all of the vital sub-cortical regions the system will still be too expensive to be marketable. Each cell in the Mind II design attempts to emulate a cortical column. The simulation he proposes requires hundreds if not thousands of CAM cells to simulate the structure of each neuron in that column. Even though his cells are simpler in nature it isn't enough to overcome the orders of magnitude increase in their number. If Mind II is barely feasable on today's computers then, assuming an 18 month Moore's law I would expect that a DeGaris-style CAM Brain would be feasable 15 years from now. Steve Grand, the creator of Creatures also used a Cellular Automata approach. Like DeGaris' work it also was patterned on a neural network model and does not appear to exploit its full computational potential. He coined a phrase, CyberLife to refer to the ideas behind his implimentation of artificial life. A version of almost all of the ideas in Mind II can be found in Creatures. Infact, it was my hope that his work would be sufficient to produce AI and that I would not have to go through the effort myself. Unfortunately his design had to cut many corners in order to work on 1995 vintage comodity hardware. The most drastic of which is the way the creatures experience their environment. Their perceptions are limited to a few points in 2-dimensional space and little else. While his design did a very good job in implementing motovators it did not implement a heirarchical control system. This is the primary reason, I beleive, that his Norns were very poor at goal-directed behavior. Any semblance of goal directed behavior was due to the limited nature of the cybernetic loop the system employed where the creature could only receive information from one stimulus at a time allowing it to react in a somewhat organized fassion relative to that stimulus. A true AI system will need to be able to accept a much larger ammount of input and then dynamicly select behaviorally relevant content as it is detected. His biological models were also loose. For example, it was possible to starve a norn well past the duration of any biological endeurance and have it suffer no real ill efects. It is apparent that this was for marketing reasons as, unfortunately, the system was not geared for research use. In all, his system was far too limited for there to be much hope at all of intelligence emerging. I would be very interested, however, to see what he would do with a practically unlimited computational budget. Another notable AI researcher is Rodney Brooks of the MIT. His efforts of the late '80s and early '90s were most remarkable in the field of AI for no other reason than they actually made sense. Instead of messing around with trees of abstract syntax, he developed robots which interacted with their environment. His early robots were equivalent of Phase 1 and, perhaps, Phase 2 of the project outlined above. Had he continued his work he would almost certainly have something really interesting by now. I really don't know what he has been doing the last ten years but I can hardly find anything new projects on his website at all. I'll give the man credit for being one of the very few AI researchers out there persuing the most obvious course of research but his follow-through is most sorely lacking. If I were him, I would have made a larger mobile robot with a richer suite of sensors, especially cameras, and at least one reasonably dexterous manipulator. Then I would have started hacking togeather a system that can perceive it's environment. Instead, his work seems to be focused on producing human-like afect display. This is only a mite and a half better than plain anamatronics. My supposition is that he has sold out and is working with a very short-sighted commercial product in mind, basically the face for the androids coming out of Japan and little more. Either that or he has just gotten too caught up in all of the organizations he is involved with. I would say more about the androids from Japan but very few details are publicly available (and in English). There are other efforts to produce AI but few of them are worth mentioning. The examples above should be sufficient to give the reader a general impression of where my ideas are situated in the broader scheme of things. Commercialization. The Mind II project, both during and after it's development, presents a number of commercial opportunities. While the AI architecture produced by this project will have some limitations that will hinder it from performing well in the most demanding environments, it will have a broad number of useful applications. Some people claim that once general AI is achieved commercial concerns will quickly be overwealmed by other impacts of the AI technology on society. It is my beleif that any intention to unleash an AI with the ability and motive to effect some change on society or the environment is criminal. The commercial model of deployment is very well tuned to allow people to choose for themselves in a supprisingly democratic fassion how they wish new technologies to affect their lives. - Accelerating the evolutionary process by making the software available to home users. During the development effort the Virtual world simulation software may have some commercial value in the same way the Creatures software attempted to gain a market. This possibility is mitigated, however, by the fact that the level of hardware required to run a population of Mind II instances is likley to be beyond what will be common for at least another few years. Another opportunity is in the simulation software itself. As this application is intensely demanding on the detail and features of the simulation software, the simulation itself may have some commercial value. - AI as a stand-alone product. The commercial applications of AI are practically limitless because a digital generally intelligent agent can take the place of virtually any knowledge worker. With a Mind II AI the task of a producer is to construct and educate instances of Mind II for the varrious tasks. Additionally, variations of the basic topology will need to be created to address unusual or specialized usage scenereos. The actual business model for this type of venture is a matter for debate with the community at large. It also is dependant on varrious technical issues with regards to the power and flexability of the AI technology itself which are not entirely forseeable. - Hardware accelerators for Mind II AI systems as commercial products. The Mind II approach, as it is outlined here, will not run very efficiently on today's processors. Architectures designed specificly for the CAM paradigm of computing will be better suited to the task. As the Mind II AI system grows in popularity a secondary market for Mind II processors will emerge. These may be packaged either as accelerator boards for existing computer systems or as stand-alone "cybernetic modules". - Robotic Systems. Perhaps the most natural application for an AI of this architecture is in the form of androids. Because the Mind II follows the human brain pattern so closely the only problem becomes adapting the control structure of the android to the AI architecture. Refferances Dr.Rodney Brooks. http://www.ai.mit.edu/people/brooks/index.shtml Dr.Hugo DeGaris. http://www.cs.usu.edu/~degaris/ Creatures Labs (what's left of it.) http://www.gamewaredevelopment.co.uk/creatures_index.php Steve Grand http://www.cyberlife-research.com/