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PubMed2003

Discourse analysis of logical memory recall in normal aging and in dementia of the Alzheimer type.

This study examined the nature of errors in prose recall made in dementia compared with normal aging. Responses by 48 young adults, 47 nondemented older adults, and 70 people with very mild or mild Alzheimer's disease to the Logical Memory subtest of the Wechsler Memory Scale were examined in a propositional analysis. Compared with young adults, healthy older adults showed good immediate recall but deficits in retention over a delay. Demented individuals made errors of omission, not commission, at immediate recall. These errors probably reflect difficulty with attentional control rather than memory per se. In terms of clinical implications, veridical scoring of the Logical Memory subtest provides more sensitive detection of very mild dementia of the Alzheimer type than the current standard criteria for scoring.

Adult↗

PubMed2003

Logic-based remodeling of the Digital Anatomist Foundational Model.

This paper describes a development cycle for the engineering of large knowledge bases: A graphical tool is used for editing and the content is transformed into a logic-based representation language. This representation is used to check the consistency of the knowledge base as well as to facilitate the reviewing process. Showing the usefulness of this approach, aspects of the Digital Anatomist Foundational Model will be transformed into a Description Logics representation. We introduce a special modeling technique to account for the representation of the complex part/whole relationships in the biomedical domain.

Anatomy↗

PubMed2003

Weaning infants with respiratory syncytial virus from mechanical ventilation through a fuzzy-logic controller.

We have previously developed a fuzzy logic controller for weaning adults with chronic obstructive pulmonary disease using pressure support ventilation (PSV). We used the core of our fuzzy logic-based weaning platform and further developed parametrizable components for weaning newborns of differing body size and disease-state. The controller was validated on neonates recovering from congenital heart disease (CHD) while receiving synchronous intermittent mandatory ventilation (SIMV). We wished to compare the efficacy of this controller versus the bedside weaning protocol in children with respiratory syncytial virus pneumonitis/bronchiolitis (RSV) in the pediatric intensive care unit (PICU). The fuzzy controller evaluated the "current" and "trend" weaning status of the newborn to quantitatively determine the change in the SIMV integrated ventilatory setting. For the "current" status it used heart rate (HR), respiratory rate (RR), tidal volume (VT) and oxygen saturation (SaO2), while for the "trend" status the differences of deltaRR/ deltat, deltaHR/ deltat, and deltaSaO2/ deltat recorded between two subsequent time points were utilized. The enumerated vital signs were fuzzified and then probability levels of occurrence were assigned. Individualized "golden" goals for SaO2 were set for each newborn. We retrospectively assessed the charts of 19 newborns, 113+/-128 days old, 5,546+/-2,321 gr body weight, weaning for 99+/-46 days, at 2-hour intervals. The SIMV levels proposed by the fuzzy controller were matched to those levels actually applied. In 60% of the time both values coincided. For the remaining 40%, the controller was more aggressive suggesting lower values of SIMV than the applied ones. The Area under the SIMV curves over time was 1,969+/-1,044 for the applied vs 1,886+/-978 for the suggested levels, respectively. The fuzzy controller adjusted for body size and disease-pattern can approximate the actual weaning course of newborns with RSV.

Female↗

PubMed2003

Using description logic to manage question corpora.

If clinical questions are to be used on a large scale as a practitioner interface to the medical knowledge base, improved methods must be developed for the semantic management of question corpora. In this project we investigate the use of description logic to manage question corpora. We propose the addition of a Q-box to a standard Description Logic knowledge base. The Q-box will contain concept descriptions that are not yet accepted as part of the T-box, but in effect represent questions about concepts already described in the T-box.

Information Storage and Retrieval↗

PubMed2003

Why don't medical textbooks teach? The lack of logic in the differential diagnosis.

Medical textbooks are an important aid in the process of diagnosing and treating patients. Medical students use these books to acquire the skills necessary for this process, while medical teachers and experienced doctors use them for teaching these competences. We posed the question whether medical textbooks are structured in such a way that medical students are taught to structure knowledge and to make a differential diagnosis in a logical way. Five major textbooks were compared with regard to four clinical problems (gastrointestinal bleeding, anaemia, oedema and heart failure). The presentation appeared to be very variable in respect of logic and systematic arrangement. In fact, it was disappointing that even in well-reputed textbooks, a systematic approach is lacking. We feel there is a need for improvement, in order to facilitate the learning of medical students and to enhance their abilities in clinical problem solving.

Diagnosis, Differential↗

PubMed1992

[Chaos research, fractals, fuzzy logic. From stereotypes to reality--consequences for medicine].

Both language and conventional mathematics aim to describe reality. Although language is more flexible, it is usually also inaccurate, while mathematics permits accurate presentations and clear prognoses. However, it is burdened by the fact that it is not everywhere applicable. Such chaotic structures as clouds, or lang-term weather forecasting, for example, cannot be expressed in terms of mathematics. Chaos researchers are attempting, in a non-linear world, to understand mathematically dynamic, apparently unordered systems. In this connection, the fractal dimension also appears--which can be employed in the area of diagnosis to define tumor contours. Fuzzy logic comes closer to reality by replacing the inflexible yes/no by a more or less option and by introducing linguistic nuances into machine-controlled processes. Chaos research and fuzzy logic teach us that there is no such thing as certainty of action or prognosis. In the world as it is, whoever claims to possess it is either naive or guilty of self-deception.

Artificial Intelligence↗

PubMedDate not supplied

Simple logical structures of medical reasoning and action.

The aim of this study is to delineate the fields of research on medical problem solving and action in which the use of logical methods may be fruitful and to describe the topics related to these fields in a way which would make easier further formal analysis. Four types of reasoning, namely, direct inference, verification of hypotheses, proving and explanation, are distinguished; simple examples of their application in the diagnostic and therapeutic inference-making are presented, and a complex, systemic character of reasoning in actual situations is described. The remarks concerning logical questions connected with the time factor, uncertainty and health values indicate the main sources of difficult problems which appear in a formal analysis. Medical action is represented as a sequence of consecutive, parallel and ramified diagnostic and therapeutic stages; the role of the plan of action and the importance of the cooperation between the doctor and the patient are stressed.

Logic↗

PubMed1980

[The logic of delusions].

The author attempts to uncover the logic behind the various delusion phenomena. Starting from the hypothesis that the paranoic interprets certain I-thou relations exclusively as auto-reference, a new conceptualization of the notion of 'auto-reference' is proposed. On the basis of a reformulated Freudian structure model, auto-reference (id) is defined as physical self-reference. With the aid of a many-valued (transclassical) logic it is shown that delusion phenomena represent mirror-like mappings of certain physical structures of the paranoic. The formal treatment of delusion structures should therefore directly indicate the composition of certain organic structures, especially brain structures, of the paranoic. As this paper tries to show, progress in delusion research can only be achieved by interdisciplinary cooperation.

Delusions↗

PubMed1981

[Logical structure graphs in the teaching of oncology].

The graduates of medical institutes are the first link in the general therapy network, where all patients with pretumor and tumor lesions are referred to for medical aid. It is the rate of their training in oncology that the number of patients with advanced malignancies depends on. To improve the teaching of oncology the writers have used the graphs of logical system, which enabled not only the student but also the teacher to concentrate their attention on the key, basic problems, to choose the necessary information and to reject an excessive secondary one. The graphs of logic system allow the student to realize and understand the structure of the subject concerned, as a whole, the relationship of separate elements under study, thus being a visual aid contributing to better mastering the subject. The former offer good grounds for a scientific approach to the teaching problems.

Logic↗

PubMed1994

Affect logic: an integrative model of the psyche and its relations to schizophrenia.

The integrative concept of 'affect logic' is based on a hypothesis concerning the laws of interaction between emotion and cognition. 'Affects' are defined as global psychophysiological states which determine the prevailing functional 'logic', i.e. the specific ways in which cognitive elements are selected and linked together. This leads to an integrative psycho-socio-biological evolutionary model of schizophrenia, in which a specific affective-cognitive vulnerability is built up in a first phase, through escalating interactions between unfavourable genetic-biological and psychosocial influences. In a second phase, the mental system is decompensated by psychosocial or biological stressors which induce psychosis. The great variability in long-term course (third phase) is conditioned by the complex interplay of many biological and psychosocial variables. The organising functions of affects are evident in schizophrenic core phenomena such as ambivalence, incoherence, and emotional flattening. This proposed model has numerous practical and theoretical implications.

Affect↗

PubMed1993

The bi-logic perception of time.

The problem of perception and conceptualisation of time in the unconscious and the conscious is seen in terms of Matte-Blanco's theories. In a short outline of his ideas, symmetrical and asymmetrical logic and his newer concept of 'bi-logic structures' are discussed. Clinical examples from the psychoanalysis of a patient with a time problem are presented to illustrate the hypothesis that a misperception and misconception of time lead in this case to obsessive-compulsive pathology. The clinical application of Matte-Blanco's postulations not only explains the psychopathology of the patient but also allows the formulation of a treatment strategy leading to a positive solution of the problem.

Adult↗

PubMed1996

The fuzzy logic of visuomotor control.

Biological sensorimotor control is characterized by the use of signals from large numbers of sensors, monitoring numerous variables. Among these are the exteroceptive signals from the eyes and ears. Many of the sensory signals are under efferent control, and the motor responses they evoke, whether at a simple reflex level or routed through the higher centres, appear to be task and context dependent. In technology the analysis and management of multiple-input, multiple-output systems clearly exceed the capabilities of classical servo control theory. In this commentary, new types of control system based on conditional logic are discussed in relation to the rules animals use to control movement. It is argued that the concepts of fuzzy logic control provide a useful and "biologically compatible" way of describing sensorimotor behaviour. An example is given of a robotic device under fuzzy control, in which behaviours are selected according to a visual assessment of motor task and context. Each behaviour is associated with a small subset of rules relating specific sensory variables to specific motor actions. The rule-based approach is also discussed in relation to neurophysiological theories regarding the interneuronal control of locomotion, including the recently adduced "parliamentary principle." The analysis and classification of behaviours and rules is seen as a useful preliminary to the future study of interneuronal systems.

Animals↗

PubMed1995

Ethical and unethical conduct in psychoanalysis. Correlations between logic, ethics and science.

This paper, written by a logician and two psychoanalysts, deals with the existence of logical relationships between ethics and psychoanalysis, which can be expressed as propositions. With a view to focusing the discussion on this point, the authors have deliberately abstained from any polemics concerning the scientific status of psychoanalysis, and concentrate on a consideration of the ethical implications of the conduct of psychoanalysts in the exercise of their profession. In this approach, the theoretical statements and technical rules of psychoanalysis as manifested in its daily practice inevitably have connexions with metaethics and normative ethics. The authors discuss in turn the ethical classification of human conduct, the classes of ethical propositions, the problem of means, ends and values, and the concrete ethical questions raised by the practice of psychoanalysis. Their argument is based on consideration of the existence of empirical, pure ethical and mixed ethical statements, analogous to the familiar categories of empirical, theoretical and mixed statements, or rules of correspondence. Mixed ethical statements are deemed to serve as new rules of correspondence, whereby logical bridges could be constructed between the factual aspect of psychoanalysis and pure ethical statements. If this approach is valid, a sufficient foundation exists to express views on the ethical characteristics of psychoanalytic conduct.

Countertransference↗

PubMed1998

Application of fuzzy logic techniques for the qualitative interpretation of preferences in a collective questionnaire for users of wheelchairs.

Active participation of users in the evaluation of technical aids is essential, since they are part of the interface with the system and constitute a fundamental source of design criteria. In this study, 88 active users of wheelchairs were interviewed by means of a written questionnaire about their opinion concerning the adaptation of his/her wheelchair to the office workplace. A conceptual framework was introduced linking objective measurements of the user-wheelchair interface to the subjective preferences expressed by the user. Discriminant analysis was used in order to select and quantify the importance of the most significant factors influencing the user's opinions. Fuzzy logic was introduced for the qualitative interpretation of the relationship between those significant factors, based on an inductive algorithm for generating fuzzy rules. Fuzzy logic enables a person to model the uncertainty within the subjective formulation of knowledge or opinions. From the results, a mismatch between actual performance of conventional wheelchairs and requirements of office work became evident. The proposed methods make it possible to determine reliable rules explaining subjective preferences; thus, they provide a flexible means of interpreting user questionnaires and obtaining new design criteria.

Equipment Design↗

PubMed1997

Disclosures and refutations: clinical psychoanalysis as a logic of enquiry.

The author argues that the empirical status of psychoanalysis has been distorted by the controversy surrounding Aristotelian and Galilean-Newtonian schemes of science, whose core ideas, respectively, are scientific concepts or forms and scientific laws. Bound by the Euclidian axiomatic tradition, Newtonian-style 'laws' do not obtain in the social sciences, and in biology they apply only at near-molecular levels, not at the level of mind. Continuing the traditional Aristotelian reliance on 'exemplars', neither Freud's nor Darwin's work fits the deductivist, infallibilistic scientific criteria used by philosophers such as Tarski, Popper or Grünbaum. Rebutting the charge that the workings of psychoanalysis are not explicit enough, this paper unfolds the logic of enquiry it utilises. In contrast to Newtonian inductivism, Popper's method of conjectures and refutations and Lakatos's method of proofs and refutations, clinical psychoanalysis employs a 'practical logic' of disclosures and refutations, a constantly evolving enquiry of multi-layered and tentative evidence of discordance and analogy. Such epistemic fallibilism, relying on a build-up of ostensive evidences rather than on 'certainties', is illustrated in the text by Moore's famous 'two-hands' argument, is held to fit in with the workings of everyday discernment and, arguably, with Darwinian evolution.

Humans↗

PubMed1976

[Elementary logic and semantic fields in aphasia].

Modern linguistics, like genetic psychology, postulate a non-linguistic basis for the structurisation of the semantic fields. If such is the case, it should be possible to observe in aphasia, where semantic deficiency predominates, a related disturbance in the semantic fields and logic. Paraxodically, such disturbances have been observed both in Broca's aphasia and in the predominantly semantic aphasia of Wernicke. A qualitative analysis shows that quantitatively identical results in the semantic aphasias of Broca and Wernicke are the result of phenomenological convergence. The related disturbance in the semantic fields and logic appears characteristic of the semantic deficiency which, in aphasic semiology, is marked by the substitution of one word for another. These finding support the theory of the relative autonomy of phonemic and semantic disorders in Wernicke's aphasia. They confirm the linguistic and genetic theory that the structure of vocabulatory is based on extralinguistic factors. They do not however provide an explantation for semantic disorders in aphasia. Further research is required to discover on what functional system articulation of the symbolic function and general operative capacity is based.

Adolescent↗

PubMed1997

Development of a fuzzy logic based system to monitor the electrical responses of nerve fiber.

A fuzzy logic based control system to monitor and control the electrical and chemical responses of nerve fibers has been designed and simulated. Fuzzy logic provides powerful reasoning mechanisms for combining information from multiple fuzzy sets.... The rule base has been developed based on the difference between the measured value and the desired value. The potential difference across each nerve fiber and the current through it has been monitored and controlled by a feedback control signal. The controller has been tested and simulated using sinusoidal and square wave forms with different frequency. The desired value was reached very rapidly. The system is capable of monitoring and controlling four nerve fibers simultaneously and allow the researcher to select different modes of operations.

Electrophysiology↗

PubMed2003

The formation of sense organs in Drosophila: a logical approach.

The genetic analysis of development has revealed the importance of small sets of interacting genes in most morphogenetic processes. The results of gene interactions have so far been examined intuitively. This approach is largely sufficient when one deals with simple interactions, a feedback circuit for example. As more components become involved, however, it is difficult to make sure that the intuitive approach gives a comprehensive view of the behaviour of the system. In this paper, we illustrate the use of a logical approach to describe the genetic circuit that underlies the singling out of sense organ precursor cells in Drosophila. We show how to apply logical modelling to a realistic problem, and how this approach allows an easy assessment of the dynamic properties of the system, i.e., of its possible evolutions and of its reactions to fluctuations and perturbations.

Animals↗