Presentation on theme: "On database keys, with an application to the Praxisproblem Derek J. SMITH Centre for Psychology University of Wales Institute, Cardiff"— Presentation transcript:
On database keys, with an application to the Praxisproblem Derek J. SMITH Centre for Psychology University of Wales Institute, Cardiff
As presented to the 9 th World Multi-Conference on Systemics, Cybernetics, and Informatics Orlando, FL, Tuesday 12 th July 2005
A BIT MORE ABOUT THE AUTHOR 1980s - specialized in the design and operation of very large IDMS databases. Since 1991 taught cognitive science and neuropsychology to Speech and Language Pathologists. Hence interdisciplinary in database, cognitive neuropsychology, and psycholinguistics. Hence fascinated by the possibility that the mind is a biological database capable of linguistic communication.
DEFINITIONS (1) “VOLITION” AND “PRAXIS” “Volition” is the exercise of “the Will”. “Praxis” comes from the Greek prassein, "to do“, and refers generally to a system’s ability to initiate voluntary physical behavior of any sort (hence we call it “dyspraxia” when something goes wrong). “Speech praxis” is the process by which the Will voluntarily initiates the expression of a given idea though the medium of spoken language.
DEFINITIONS (2) “REDUCTIONISM” Reductionism is explaining complex phenomena in terms of their parts. E.g. how nuts, bolts, etc., make an automobile. However, there’s a big problem with reductionist explanations, because systems are frequently greater than the sums of their parts, and you lose much of their essence as soon as you start taking them apart. This is especially true of the mind, which seems to be massively more than the sum of its neurons. Following Levine (1983), we favor the term “Explanatory Gap“ for this problem.
PLAN OF ATTACK This paper looks at the explanatory gap problem in speech praxis, and shows how that gap might be narrowed in an artificial cognitive system using CODASYL-style database keys. This means bringing together two hitherto unconnected areas of knowledge, so we shall open with “background" sections on (a) the psycholinguistics of speech praxis, and (b) the use of database keys in CODASYL databases. We’ll then present a pseudocode demonstration of how the one can help the other.
We’ll also be telling you a little about what went on at this place a while back.
LORDAT (1843) FIVE STAGES OF SPEECH PRAXIS So what do psycholinguists know about speech praxis? Well in 1843 the French neurologist Jacques Lordat identified five processing stages within speech production, and described the first of these as “isolating” the idea to be expressed in words. The four subsequent processes then co-operate in shaping the final spoken output, as now shown …..
LORDAT (1843) Each stage receives a coded message from the one before, adds to it in some clever way, and then passes it on to the one after.
LORDAT (1843) FIVE STAGES OF SPEECH PRAXIS Lordat’s explanation was duly incorporated into a number of later 19th century aphasiological models, and is worth noting because in one form or another it is still with us today. The explanatory diagrams are typically either “A-shaped” (with the “clever” bits – the mind’s “higher functions” - at the top) or “X-shaped” (with the clever bits at the central cross-over point). Here are two of the A-shaped ones, one old and one new …..
LICHTHEIM (1885) TWO-LAYER CONTROL HIERARCHY
NORMAN (1990) MODERN THREE-LAYER HIERARCHY
MODERN SPEECH PRODUCTION MODELS Speech production did not become a popular study topic until 1971, when Fromkin's "Utterance Generator" model extended Lordat from five stages to six. The most popular modern models of speech production come from the Max Planck Institute's Willem Levelt and the University of Arizona's Merrill F. Garrett. But they all take the same basic shape, so we’ll work for now with Fromkin’s …..
FROMKIN’S FIRST THREE STAGES Stage 1 – Pre-Lexical Semantics: Decides the meaning to be conveyed. Code not known, but preverbal. Stage 2 – Pre-Lexical Syntax: Decides the grammatical skeleton of the sentence. Code not known, but preverbal. Stage 3 – Lexical: Selects the necessary “content words” (i.e. nouns and verbs) from the mental lexicon, thus making ideas verbal for the first time. It’s worth remembering these three stages as a unit, because we’ll be returning to them later.
FROMKIN’S LAST THREE STAGES Stage 4 – Prosody: Adds in emotionality via intonation pattern. Code not known, but mediated by the hindbrain. Stage 5 – Phonology: Decides the final syntax and word morphology. Phonemic code. Stage 6 - Final Sound Production: Commits concrete sounds - "allophones“ – to the motor nerves for respiration, phonation, and articulation. We’re not really concerned with these three stages in this paper, because they are all post-semantic.
STATE-OF-THE-ART PSYCHOLINGUISTIC MODELING The PALPA (Kay, Lesser, and Coltheart, 1992) is a typical X-shaped psycholinguistic diagram (that is to say, the Will is located in the middle of the diagram, not at the top). Here it is …..
The PALPA All input channels are now at the top, and all output channels at the bottom. Ideation is in the centre box, and speech praxis is the bottom left processing leg. Our question is, how do ideas make it out of the centre box and down the first arrow!
SPEECH ACTS AND IDEATION (1) In fact, praxis is so complex that it has its own science – “pragmatics” ….. ….. and its own very powerful theory - Speech Act Theory (Austin, 1962; Searle, 1969). Speech Act Theory studies not just the words people use, but the units of intention – the “speech acts” which preceded those words. Pragmatics is thus the science of the centre box and the first arrow …..
SPEECH ACTS AND IDEATION (2) Each speech act is (a) calculated to achieve some discrete behavioral "perlocutionary" effect, but (b) has not yet been fully formed lexically or grammatically. The code is preverbal - perhaps “sprites” or ideograms of some sort. Speech acts haven’t been very well modeled yet, and so remain poorly understood (although we hope to start the ball rolling with this paper).
SPEECH ACTS AND IDEATION (3) Speech Act Theory has its own very difficult jargon. In this paper, for example, we shall be hearing about a “directive” speech act, with a “requestive” subtype, invoking the core verb “to summons”. The mind has about a 1000 different speech acts to choose from (more details in Bach and Harnish, 1979).
ANIMATED PALPA – SMITH (2000) So what might a speech act look like? Where do these all-important sprites come from, where do they go, and what happens to them when they get there? To get a better idea of the process, we need to see the static flow diagram “in motion”. So here, from Smith (2000), is sentence production more or less in real time, for the specimen sentence “The Redcoats are coming” …..
OUR BASIC PROPOSAL So how might a network database help? Well above all it would help demonstrate how mental content is progressively accessed during sentence production. Not just ideation and initiation (Stages #1 and #2), but lexical expansion (Stage #3) as well. Here’s some important background (we’ve taken Computer Associates' IDMS system, a 1969 network database, as the class-defining CODASYL database) …..
ABOUT NETWORK DATABASES (1) IDMS DATABASE KEYS Data is organized into "records“. Filestore is organized into block-sized "pages“ of up to 256 records per page. The resulting page-line address is known as the "database key" for that record.
ABOUT NETWORK DATABASES (2) IDMS DIRECT ACCESS IDMS is a supremely flexible data retrieval tool. It offers 10 ways of finding things, the most fundamental of which is direct access.
ABOUT NETWORK DATABASES (3) IDMS DIRECT ACCESS A hashing algorithm computes the page number from the logical record key (Dumey, 1956). Once a record has been located, its database key is automatically stored by the DBMS as a “currency”.
ABOUT NETWORK DATABASES (4) CHAIN POINTER ACCESS IDMS also arranges for certain data records to "own" certain others, thus capitalizing on the data's natural one-to-many "set" relationships.
ABOUT NETWORK DATABASES (5) CHAIN POINTER ACCESS Each record includes in its physical record length the database key of the next record in that set. These “chain pointers” are a storage overhead, but one which is well worth paying. Just like the brain during semantic or lexical categorization.
ABOUT NETWORK DATABASES (6) “CURRENT OF SET” ACCESS Once a record has been located, its database key is automatically stored by the DBMS, identifying it as “current of set” for the set in question. This makes said record effectively direct access, even if it had originally taken a lot of chain pointering to track down. Just like the brain during medium term recall.
ABOUT NETWORK DATABASES (7) IDMS TRAVERSALS In practice, the final outputs of a database interrogation are always composites of fragments of data collected from potentially hundreds of points across the network. The process of collecting these fragments is known as “traversing” the database. The inventor of the process, Charles W. Bachman, winner of the 1973 A.C.M. Turing Award, once likened it to "navigating" (Bachman, 1973). Traversals are hard to plan, but then easy to achieve using only a handful of "Data Manipulation Language" (DML) verbs, such as OBTAIN CALC, OBTAIN NEXT, MODIFY, and ERASE.
TOWARDS AN IDMS "MINDBASE" (1) DATABASE KEYS AND MACHINE VOLITION OK, so let’s start to bring these thoughts together ….. Supposing the mind were an IDMS database, then for database traversal purposes, only the first three of Fromkin's six stages would need to be considered. This is because they are the ones which access the semantic network. Everything else is just number-crunching. Let’s look at those stages one by one …..
TOWARDS AN IDMS "MINDBASE" (2) “ISOLATING” A PROPOSITION Stage #1 is where we tap into the mind’s central stream of contextually coherent propositional thought. Each successive proposition will activate a number of the mental sprites we have been talking about. Always and, and sometimes also,, and. Every now and then, a small subset of propositions becomes salient enough to warrant initiating a communicative act, whereupon that particular unit of ideation is "isolated" ready for production.
TOWARDS AN IDMS "MINDBASE" (3) SPEECH ACT SELECTION Stage #2 is responsible for converting the afore- mentioned subset of propositions into a speech act of some sort. The point is that by selecting a particular speech act, we restrict our choice of possible sentence structures to only a handful of options. It is rather like opening sealed orders on a military mission - one specific action gets selected from a repertoire of many, you get told what to do next, and the desired outcomes are specified.
TOWARDS AN IDMS "MINDBASE" (4) LEXICAL EXPANSION Stage #3 is where we start attaching words to what until now have been preverbal codes. Unfortunately, this process does not always work cleanly – see our e-paper on “Speech Errors” at
TOWARDS AN IDMS "MINDBASE" (5) STAGES #1 TO #3 IN PSEUDOCODE Here are some extracts from the pseudocode set out in the written version of this presentation. The selections show the following four circumstances ….. (1) Isolation of ideation. (2) Selection of a speech act by direct access. (3) Chain pointer use in opening a set. (4) Set currency use in continuing a set.
INDICATIVE IDMS PSEUDOCODE (1) ISOLATING PAUL REVERE’S IDEA Different combinations of external circumstances demand different actions ….. IF AGENT = …. …. ELSE IF AGENT = “BRITISH COLUMN” IF ACTION = ““ On null condition ….. NEXT-SENTENCE ….. no action is necessary ELSE IF ACTION = “MOVING NORTHWEST” MOVE “PLAN X” TO SPEECH-ACT-CODE NEXT SENTENCE ELSE IF …......
INDICATIVE IDMS PSEUDOCODE (2) EXAMPLE OF DIRECT ACCESS Once a given set of circumstances has prompted a particular pre-learned plan of action, the detailed response can be retrieved from long-term memory ….. MOVE SPEECH-ACT-CODE TO ACT-RECORD-KEY. OBTAIN CALC ACT-CONTROL-RECORD. The “sealed orders” on this occasion specify a “directive” speech act, with a “requestive” subtype, and the core verb “to summons”.
INDICATIVE IDMS PSEUDOCODE (3) EXAMPLE OF CHAIN POINTER ACCESS The waypoints on the road to Lexington are themselves in long-term memory, organized on an owner/member set basis ….. MOVE “MIDDLESEX COUNTY” TO DISTRICT-KEY. OBTAIN CALC DISTRICT. We don’t actually need this record, but we have to get it because it contains the chain pointer to the first set member ….. OBTAIN FIRST MINUTEMAN IN MINUTEMEN-IN- DISTRICT.
INDICATIVE IDMS PSEUDOCODE (4) EXAMPLE OF SET CURRENCY USE Having processed one minuteman, we have to relocate its record before getting the next, again because we need the chain pointer it contains ….. OBTAIN CURRENT MINUTEMAN. OBTAIN NEXT MINUTEMAN IN MINUTEMEN-IN-DISTRICT.
CONCLUSION (1) WHAT WE HAVE SEEN SO FAR The pseudocode is entirely typical of IDMS programming, in that you have to pay precise attention (a) to where you are in the data network, and (b) to how you are going to get to where you want to be next. The record and set currency mechanisms are invaluable in this respect. We may identify three specific potential advantages of the IDMS metaphor to ALL students of the mind …..
CONCLUSION (2) IDMS IS LIKE FOR LIKE WITH BIOLOGY The network database is just that, a network, and so, too, is biological associative memory. And yet only a microscopic proportion of the $billions spent on AI in the past 50 years has utilized a physical network architecture.
CONCLUSION (3) IDMS IS TOTALLY REDUCIBLE The activity of an IDMS mindbase is automatically totally reducible. The DML is pre-processed to native COBOL, and then put through the regular COBOL compiler to produce object code. Both conversions are 100% trackable, and in debug mode we can even execute the object code one instruction at a time. This is important because what cognitive theorists are really about is reverse engineering - “de-compiling” neural object code in order to understand what on earth it is up to.
CONCLUSION (4) IDMS MIMICS NEUROCHEMISTRY IDMS's use of database currencies is uncannily similar to the brain's physiological memory mechanisms. E.g. “second messenger neurotransmission” and “calcium switching”. In other words, biological long-term memory looks to have its own keys and currencies (Smith, 1997). Or to put it another way, closing the explanatory gap is a code-breaking exercise of sorts!
CONCLUSION (5) CRYPTANALYSIS IN COGNITIVE SCIENCE The building we saw earlier was “Station X” – Bletchley Park – The UK Code and Cipher School during World War Two, where Alan Turing helped decode the Nazi Enigma signal system …..
CONCLUSION (6) THE COLOSSUS ….. and the birthplace in December 1943 of the world’s first programmable electronic binary digital computer.
CONCLUSION (7) THE COLOSSUS BUILDING ….. which was successfully rebuilt by preservation enthusiasts between 1994 and 1996.
CONCLUSION (8) TURING’S OFFICE (HUT 8) NOWADAYS The same Alan Turing, incidentally, who inspired the A.C.M. Turing Award, saw the mind as computable, and devised the “Turing Test” of machine consciousness.
CONCLUSION (9) SPECIFIC PROPOSAL The best way across the explanatory gap would be to approach it as a code-breaking exercise, starting with neural “crackle” as the given “intercept”, and reverse engineering it back to the DML of the original ideation ….. ….. and looking out especially for the location of the biological “currency tables”. IDMS may even assist students of artificial consciousness at the same time …..
CONCLUSION (10) ARTIFICIAL CONSCIOUSNESS A leading consciousness theorist, David Chalmers, has argued that if a technically advanced theory could one day explain at the reductionist level how the brain thinks, it would still be "silent about how these processes might give rise to conscious experience" (Chalmers, 1995, p64). We submit IDMS as a candidate for Chalmers' "technically advanced theory“ ….. ….. and suspect that its reducibility and capacity for slow motion execution will reflect on the “how” question as well.
THE END Or is it??
REFERENCES Austin, J.L. (1962). How to do Things with Words. Oxford: Oxford University Press. Bach, K. and Harnish, R.M. (1979). Linguistic Communication and Speech Acts. Cambridge, MA: MIT Press. Chalmers, D.J. (1995). The puzzle of conscious experience. Scientific American, 273(6): Levine (1983) Fromkin, V.A. (1971). The non-anomalous nature of anomalous utterances. Language, Vol. 47, pp Searle, J.R. (1969). Speech Acts: An Essay in the Philosophy of Language. Cambridge: Cambridge University Press. Smith, D.J. (1997). The IDMS Set Currency and Biological Memory. Cardiff: UWIC. [ISBN: ] Smith, D.J. (2000). A slow-motion video analysis of information feedback in a computer-animated psycholinguistic model. Computer-animated poster presented 10th April 2000 at the Tucson Towards a Science of Consciousness conference, University of Arizona, Tucson, AZ.