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00100 THE CENTRAL PROCESSES OF THE MODEL
00200
00300
00400 (THIS CHAPTER REQUIRES MANY FLOW DIAGRAMS- SEE BACK OF MS)
00500
00600 Only the major processes will be described in detail
00700 sufficient to illustrate the logic of the algorithm. Many
00800 "housekeeping" procedures are needed to run the model but no
00900 understanding of them is necessary to follow the main flow of symbol
01000 processing. In the next paragraph I will give some examples of
01100 "housekeeping" only to illustrate what little interest they have for
01200 the nonspecialist reader.
01300 The first theoretically uninteresting procedure executed is
01400 one of intiialization which checks to make sure the data-base has
01500 been read in and sets a number of variables to their starting values.
01600 Some of these variables serve as flags or indices pointing to the
01700 topic under discussion or to the last self-topic discussed. Other
01800 variables are set by the interviewer who can choose to run a weak or
01900 strong version of the model. If the weak version is elected, affect-
02000 variables of ANGER and FEAR can be set to `low' or `mild'
02100 values,while MISTRUST can be set to `mild' or `high'. The
02200 interviewer also has the option of following the internal workings of
02300 the model which can be displayed in "windows" on a console. After
02400 this initialization the algorithm prints out `Ready' to indicate to
02500 the interviewer he may now enter his input.
02600
02700 After the input expression is assigned a sentence type
02800 (statement, question or imperative), it then serves as the input
02900 argument to the major procedures which deal with (in order) special
03000 reactions, delusional references, self references, flare references,
03100 interviewer-interviewee relations, miscellaneous expressions and
03200 self-scanning.
03300
03400 SPECIAL REACTIONS
03500
03600 This procedure produces appropriate reactions to special
03700 types of input expressions. If the input consists simply of the
03800 letter `S' {the means by which an interviewer indicates silence over
03900 a teletype), then the algorithm chooses a linguistic response from
04000 the `Silence' list. The linguistic output responses are not generated
04100 word-by-word. They consist of pre-formatted English expressions
04200 stored in the data-base on ordered lists.
04300
04400 The procedure which selects the next reply from the relevant
04500 response list also removes that response from the list so it will not
04600 be output twice. Thus, in this case, where repeated silence is
04700 being detected and if there are no more responses on the `Exhaust'
04800 list {i.e. the `Exhaust' list is itself exhausted} , PARRY would
04900 end the dialogue.
05000
05100 An `Exhaust' list represents a boundary condition in the
05200 model. That is, since the model has a limited number of linguistic
05300 responses for each topic it can discuss, when these responses are
05400 exhausted PARRY must have some way of dealing with a large number
05500 of conceptually equivalent repetitions on the part of the
05600 interviewer. When a response list is exhausted, the model expresses
05700 a wish to change the topic and, as mentioned, when the `Exhaust' list
05800 itself is exhausted, PARRY ends the dialogue. Since this process
05900 is true of all instances in which the response list is exhausted, it
06000 will not be mentioned again. I trust the reader will remember that
06100 this what happens each time this boundary condition is reached.
06200
06300 The second case handled by this procedure consists of input
06400 expressions in which the interviewer states or insinuates that the
06500 model is mentally ill. This condition is detected by finding "you"
06600 and a nearby (within three words) member of the `Abnormal' list in
06700 the input. The inputs:
06800
06900 {1} DR.- YOU NEED TREATMENT.
07000
07100 {2} DR.- YOU ARE DELUSIONAL.
07200
07300 {3} DR.- DO YOU THINK YOU MIGHT BE PARANOID?
07400
07500 would satisfy this condition.
07600 If the input is a question, as in {3}, ANGER is increased by
07700 an smaller amount of its current value than if it is a statement,
07800 Thus a question is interpreted as an implicit insult compared to the
07900 explicit insult of a direct statement.
08000
08100 The linguistic response now chosen is selected from the `Alien'
08200 list, e.g.
08300
08400 {4} PT.- I THINK I KNOW WHAT YOU DOCTORS ARE UP TO.
08500
08600 If conditons for the procedure handling special reactions are
08700 not found to obtain, the algorithm next attempts to recognize
08800 references to delusions.
08900
09000 DELUSIONAL REFERENCES
09100
09200 The strong version of the model contains in its data-base a
09300 delusional network of beliefs about the Mafia. The next procedure
09400 called scans the input expression looking for a reference to this
09500 delusional network. As will be seen, reactions to the first
09600 reference differ from reactions to subsequent references. The
09700 conceptual contentives of the delusional net are classified in the
09800 data-base into `strong' and `ambiguous' terms. Thus "murder" is a
09900 strong term whereas "bug" (as mentioned in chapter 4), is ambiguous.
10000 If delusional terms are detected in the input, a variable is set to
10100 the list of terms found and the terms are then deleted from the
10200 delusional word list for reasons which will become clear later.
10300
10400 Two situations in the interview must be distinguished, one in
10500 which a delusional topic occurs for the first time and one in which
10600 some aspect of the delusional net is under discussion or has been
10700 under discussion and is now being taken up again. Since the topic
10800 of the Mafia is a fear-eliciting, any reference to it for the first
10900 time raises FEAR by an increment much greater than if the topic has
11000 already been discussed. The concept of `mafia' is represented in the
11100 data-base by a node in a weighted and directed conceptual graph.
11200 ((DRAWING OF GRAPH HERE) Horses → Horseracing → Bookies
11300 →Gangsters → Rackets → Mafia ↑ ↑ Gambling Police ↑ ↑↑ Money
11400 Italians)). The nodes in the graph represent "flare" concepts to
11500 which the model is particularly sensitive. Associated with these
11600 nodes are small stories which the model can narrate about each of
11700 them as a theme. Nodes closer to the Mafia node are weighted higher
11800 to represent the notion that they are of greater concern since they
11900 bear more directly on the delusional network. If a Mafia topic
12000 appears for the first time , pointers in the directed graph of flare
12100 concepts must be modified accordingly since the Mafia node has the
12200 highest weight in the graph. A topic such as "bookies", while
12300 leading eventually to Mafia beliefs, is of much less importance than
12400 Mafia-topics. But if "bookies" comes up in the interview, the
12500 algorithm must know whether or not the Mafia has already been
12600 discussed. Also, if an introductory-topic {see p.0OO} or subtopic
12700 was under discussion when reference to a Mafia-topic is made, the
12800 algorithm must unset the introductory-topic indicator.
12900
13000 Since the model strives to tell its story about the Mafia, a
13100 flag is set to indicate that, should the topic be changed by the
13200 interviewer, PARRY should return to the current point in its
13300 story under appropriate circumstances, e.g. when the interviewer
13400 asks a non-specific question or requests any information the patient
13500 wishes to volunteer.
13600
13700 If the interviewer's input expression contains a reference to
13800 the delusional net, a delusional statement is output. But which one?
13900 If this is the first time the topic has come up, the algorithm
14000 outputs the first statement of its delusional story. From then on
14100 the output delusion selected depends on what has been said, what is
14200 still unsaid, and what the interviewer has said about the previous
14300 delusional statement. Thus the most recent delusional statement is
14400 saved along with expected anaphoric references, anticipating that the
14500 interviewer may subsequently ask a question or make a statement about
14600 it.
14700
14800 One special case must be noted. If the values of ANGER, FEAR
14900 and/or MISTRUST are extremely high (above a particular threshold),the
15000 program will refuse to discuss Mafia-topics at all since it is too
15100 `upset' to talk about this most sensitive area.
15200
15300 To make some of these operations more intelligible, let us
15400 consider interview examples. Suppose at some point in the interview
15500 the doctor asks a standard first-interview question as follows:
15600
15700 .V
15800 {5} DR.- DO YOU EVER HAVE THE FEELING YOU ARE BEING WATCHED?
15900
16000 If this is the first reference to the delusional net, FEAR will
16100 increase greatly and the linguistic response will be:
16200
16300 {6} PT.- YOU KNOW, THEY KNOW ME.
16400
16500 In making this response, the model must expect from the interviewer a
16600 number of typical questions of the wh-type as well as rejoinder
16700 statements. The use of "they" by the interviewer in his response to
16800 the model's output is assumed to be an anaphoric reference to the
16900 "they" PARRY is talking about. Although it is likely the
17000 interviewer will react to the model's output of {6}, the algorithm
17100 must be prepared for the possibility that he will change the topic.
17200 Hence if the interviewer at this point asks some non-sequitur
17300 question such as:
17400
17500 {7} DR.- HOW LONG HAVE YOU BEEN IN THE HOSPITAL.
17600
17700 the program recognizes that no reference to the delusional topic has
17800 been made and answers the question just as though it had been asked
17900 in any other context. This ability to deal with input in a flexible
18000 manner is important because of the many contingencies which can occur
18100 in psychiatric dialogues.
18200
18300 If the topic is changed abruptly in this way by an
18400 interviewer, the algorithm `remembers' that it has output its first
18500 delusional statement of {6}. When the interviewer makes another
18600 neutral delusional reference, the next `line' of the delusional story
18700 will be output, e.g.
18800
18900 {8} PT.- THE MAFIA REALLY KNOW ABOUT ME.
19000
19100 The ability to answer typical wh- and HOW questions depends on how
19200 much conceptual information is contained in the delusional belief
19300 being addressed. For example, suppose PARRY replied as in {6}
19400
19500 {6) PT.- THEY KNOW ABOUT ME.
19600
19700 and the interviewer then asked:
19800
19900 {9} DR.- WHERE DO THEY KNOW ABOUT YOU?
20000
20100 If the expectancy-anaphoras contain no "where", then a question about
20200 location cannot be answered. In this default situation, the
20300 algorithm recognizes the anaphoric "they","know" and "you". Hence it
20400 knows at least that the topic has not been changed so it outputs the
20500 next statement in the delusional story;
20600
20700 (9) PT.- THEY KNOW WHO I AM.
20800 and again anticipates questions and rejoinders pertaining to this
20900 statement.
21000
21100 In constructing the data-base of beliefs, we tried to pack as
21200 much information in each belief as any `reasonable' (like ourselves)
21300 interviewer might request. However, one cannot anticipate everything
21400 and when some unanticipated information is requested, another
21500 relevant reply must be substituted. This heuristic may seem less than
21600 perfect but there is little else to do when the model simply lacks
21700 the pertinent information. By the way, humans do this also.
21800
21900 When the interviewer shows interest in the delusional story,
22000 PARRY continues to output assertions appropriate to the dialogue.
22100 However, when the interviewer expresses doubt or disbelief about the
22200 delusions, ANGER and FEAR increase and the interviewer becomes
22300 questioned as in:
22400
22500 (10) PT.- YOU DON'T BELIEVE ME, DO YOU?
22600
22700 Such an output expression attempts to prompt the dialogue towards the
22800 relation between the interviewer and the model which will be
22900 described later ( see p.000).
23000 If no delusional reference at all is detected by this
23100 procedure , the algorithm attempts the next function which searches
23200 for certain types of references to the self.
23300
23400
23500 SELF REFERENCES
23600
23700 Since the main concern of a psychiatric interview consists of
23800 the beliefs, feelings, states and actions of the patient, the model
23900 must be able to answer a large number of questions about its `Self'.
24000
24100
24200 If the input is recognized as a question and no topic is
24300 currently under discussion and the question refers to the `Self',
24400 then it is assumed temporarily that it will refer only to a main
24500 self-topic. These main or "introductory" self-topics (age, sex,
24600 marriage, health, family, occupation, hospital stay, etc.) in turn
24700 have sub-topics to varying depths. For example, suppose the
24800 interviewer asks:
24900
25000 (12) DR.- HOW DO YOU LIKE THE HOSPITAL?
25100
25200 Since "hospital" is a main `introductory' topic with several levels
25300 of sub-topics, the algorithm answers the question with
25400
25500 (11) PT.- I SHOULDN'T HAVE COME HERE.
25600
25700 and then anticipates a variety of likely questions such as "What
25800 brought you to the hospital?", "How long have you been in the
25900 hospital?", "How do you get along with the other patients?", etc.
26000 Each of these questions brings up further topics, some of which
26100 represent a continuation of the main topic "hospital", but others of
26200 which represent a shift to another main introductory topic, e.g.
26300 "other patients". Since many of the inputs of the interviewer
26400 consist of ellipses or fragments, the algorithm assumes them to refer
26500 to the topic or subtopic under discussion. If some topic is being
26600 discussed, the algorithm checks first for a new main topic, then for
26700 a follow-up to the last subtopic, then (unless the subtopic is itself
26800 a main topic, as for example "other patients" in the above) for a
26900 follow-up to the last main topic. Thus continuity and coherence in
27000 the dialogue are maintained.
27100
27200 If some meaning cannot be extracted from the question but it
27300 is recognized at least that a question is being asked, a procedure is
27400 called which attempts to handle certain common miscellaneous
27500 questions which are difficult to categorize. These include the
27600 space-time orientation questions ("What day is this?") and everyday
27700 information ("Who is president?) asked by psychiatrists in a
27800 mental-status examination to test a patient's awareness and
27900 orientation. Some quantitative "how" questions ("how many", "how
28000 often", "how long") are here recognized. Since any adjective or
28100 adverb can follow a "how", one of the limitations of the model is its
28200 inability to handle all of them satisfactorily because the relevant
28300 information is lacking in the data-base. If absolutely no clues are
28400 recognized in the question, the algorithm is forced to output a
28500 noncomittal reply such as:
28600
28700 (12) PT.- WELL, I DON'T KNOW.
28800
28900 This function also checks for statements about the self which
29000 are taken to be insulting or complimentary. Naturally the presence of
29100 a negator in the input reverses the meaning. Thus
29200
29300 (13) DR.- YOU DON'T SEEM VERY ALERT.
29400
29500 s classified as an insult whereas
29600
29700 (14) DR.- YOU ARE RIGHT.
29800
29900 is considered complimentary and benevolent.
30000
30100 Among the introductory self-topics are those which constitute
30200 sensitive areas, e.g. sex, religion and family. If the interviewer
30300 refers to one of these areas, the value of ANGER increases sharply
30400 and a response is selected from one of the lists categorized as
30500 `hostile', `defensive', `personal' or `guarded', depending on the
30600 level of MISTRUST at the moment. For example, if the interviewer
30700 asks a question about PARRY'S sex life, it first replies with:
30800
30900 (13) PT.- MY SEX LIFE IS MY OWN BUSINESS.
31000
31100 If the interviewer persists or even later tries to ask about sex, the
31200 model will respond with a hostile reply, such as:
31300
31400 (14) PT.- DO YOU KNOW WHAT YOU ARE DOING?
31500
31600 The particular sensitive areas in the model are part of the
31700 initial conditions specific for this hypothetical patient. Of
31800 course, these topics are commonly found to be sensitive areas in
31900 human patients.
32000
32100 The model operates sequentially trying one major process
32200 after another. If it has come this far, (that is, having tested for
32300 special reactions, delusional references and self references without
32400 recognizing anything in the input pertinent to these procedures), it
32500 proceeds to the next process which handles flare references.
32600
32700 FLARE REFERENCES
32800
32900 The data-base contains a directed graph of concepts involved
33000 in the model's `stories'. PARRY has small stories to tell about
33100 horseracing, gambling, bookies, etc. The major concepts of these
33200 stories are termed "flare" concepts since they activate stories which
33300 are differentially weighted in the graph.
33400
33500
33600 In the strong version of the model, the concept `Mafia' is
33700 given the highest weight, while in the weak version the concept
33800 `Rackets' is most heavily weighted. In both versions `Horses' has
33900 the lowest weight. The weights are assigned to the concepts and not
34000 individual words or word-groups denoting the concepts.
34100
34200 The graph is directed in the sense that reference to
34300 horseracing elicits the first line of a story about horseracing. When
34400 a story is ended, a prompt is given to the interviewer to discuss the
34500 next story in the graph which involves `bookies'. The model strives
34600 to tell its stories under appropriate conditions and leads the
34700 interviewer along paths of increasing delusional relevance. Much
34800 depends on whether the interviewer follows these leads "benevolently"
34900 and reacts to the prompts.
35000
35100 The first step in this procedure is to scan the input for a
35200 flare concept having the highest weight. Thus if a flare concept is
35300 already under discussion, a weaker new flare will be disregarded. If
35400 the flare concept is one in a story which has already been partially
35500 told, then a prompt is offered regarding the next story-node in the
35600 graph.
35700
35800 If a question is asked about the events of a story, the model
35900 tries to answer it. Also the model is sensitive to whether the
36000 interviewer is showing interest in the story or whether he tries to
36100 change the subject or expresses a negative attitude, such as
36200 disbelief.
36300
36400 If the interviewer indicates a positive attitude towards the
36500 story, then benevolence is recognized and the variables of ANGER,
36600 FEAR and MISTRUST decrease slightly after each I-O pair. ANGER
36700 decreases more rapidly than FEAR while MISTRUST, being a more stable
36800 variable once it has risen, decreases least.
36900
37000 If no flare concepts are recognized in the input, the model
37100 next tries to detect if a reference is being made to the relation
37200 between the interviewer and the model. In an interview interaction
37300 there exist two situations, the one being talked about and the one
37400 the participants are in at the moment. Sometimes the latter situation
37500 becomes the former, that is, the one talked about.
37600
37700 INTERVIEWER-INTERVIEWEE RELATIONS
37800 As described in Chapter 4, the algorithm must be ready to
37900 handle input referring to the relation between interviewer and model.
38000 The simplest cases are exemplified by expressions such as:
38100 (15) DR.- I UNDERSTAND YOU.
38200 (16) DR.- YOU DO NOT TRUST ME.
38300 Those phrases in an expression which can appear between "I" and "you"
38400 or between "you" and "me" we classified as representing a positive or
38500 negative attitude on the part of the interviewer. Thus expression
38600 (15) is taken to be positive whereas (16) is negative because,
38700 although it contains a positive verb, the verb is negated.
38800 If a positive attitude is expressd by the interviewer, FEAR
38900 and ANGER decrease. FEAR and ANGER increase depending on the
39000 conceptualizations of the input. These attitudes of the interviewer,
39100 as interpreted by the model, are reflected in the values of the affect
39200 variables.
39300 Associated in the data base with each type of attitude
39400 expression expected are lists of appropriate output expressions. Thus
39500 in reply to:
39600 (16) DR.- I UNDERSTAND YOU.
39700 the model would reply:
39800 (17) PT.- I'M GLAD YOU DO.
39900 or
40000 (18) PT.- I APPRECIATE YOUR TRYING TO UNDERSTAND.
40100 or some equivalent expression depending on values of the affect
40200 variables. When ANGER and FEAR are high, positive attitude
40300 expressions are interpreted as insincerity and hence evoke hostile
40400 replies.
40500 The remainder of input expression types thus far not
40600 discussed are handled by a procedure for miscellaneous expressions.
40700 MISCELLANEOUS EXPRESSIONS
40800
40900 This procedure deals with all those interviewer expressions
41000 from which no clear conceptualization can be formed. The only thing
41100 which can be determined is perhaps the sentence-type of the input.
41200 Presented with one of these expressions, if FEAR is extremely high
41300 PARRY signs off without a farewell expression and cannot be
41400 contacted through further natural language input. If FEAR is high
41500 but not extreme, and the input is recognized as a question, the model
41600 chooses a reply from a list which brings up the attitude of the
41700 interviewer as in:
41800 (19) PT.- WHY DO YOU WANT TO KNOW?
41900 or
42000 (20) PT.- YOU PRY TOO MUCH.
42100 If the input is recognized as a statement, a reply is chosen from a
42200 list which indicates some degree of anxiety:
42300 (21) PT.- WHO ARE YOU REALLY?
42400 (22) PT.- YOU ARE MAKING ME NERVOUS.
42500 If ANGER is high and the input is a question, a reply is chosen from
42600 a list designed to express hostility as in:
42700 (23) PT.- DO YOU KNOW WHAT YOU ARE DOING?
42800 (24) PT.- PERHAPS YOU ARE JUST POSING AS A DOCTOR.
42900 Sometimes in these default conditions the flag set in the
43000 procedure for delusional references allows the model to continue by
43100 giving the next line in its delusional story. If the story is under
43200 discussion, continuity is maintained. But if it is not, the model
43300 appears to ignore the input and jumps back to one of its previous
43400 preoccupations. In this instance the observed property of rigidity
43500 is a function of linguistic non-comprehension and not of the paranoid
43600 processes per se. Increasing the model's ability to comprehend
43700 conversational language would remedy this deficiency.
43800 If a story flag has not been set by a previous discussion in
43900 the interview and ANGER and FEAR are not high, the algorithm tries to
44000 see if the input is some type of general prompt from the interviewer
44100 such as:
44200 (25) DR.- GO ON.
44300 or
44400 (26) DR.- TELL ME MORE.
44500 If so, PARRY continues with its current story or attempts to
44600 initiate another story.
44700 If none of these conditions hold, the procedure ANSWER
44800 is called. This procedure handles a group of common special-case
44900 miscellaneous questions such as:
45000 (27) DR.- HOW DO YOU DO?
45100 and miscellaneous statements such as:
45200 (28) DR.- HI.
45300 (29) DR.- GOOD EVENING.
45400
45500 SELF SCANNING
45600 The final major procedure in the algorithm scans what the
45700 model has chosen to output. That is, it treats its own output as
45800 input. If this expression contains a flare or delusional reference,
45900 the appropriate flags are set and FEAR is raised slightly, but not as
46000 much as if this expession had come from the interviewer. In this way
46100 the model "frightens itself" by what it says about a frightening
46200 topic.
46300
46400 SUMMARY
46500 To recapitulate the operations of the model, it first
46600 attempts a linguistic recognition of the input by looking for
46700 patterns which indicate its meaning. The internal and external
46800 reactions of the model depend on whether the meaning is classified as
46900 malevolent, benevolent, or neutral. Internal reactions consist of
47000 adjusting the values of affect variables of anger, fear and mistrust.
47100 The model also keeps track of the topic under discussion and by means
47200 of anaphora-expectancy functions, anticpates what might be said. The
47300 external output of a natural language expression depends on the
47400 nature of the input, the topic under discussion and the values of the
47500 affect varaibles.
47600 The systemicity of the model is obvious. We now come to its
47700 testability. How can we compare the model to its subject, its
47800 naturally-occurring counterpart, so that we can judge its degree of
47900 correspondence to facts of observation?