Gil R, Arroyo-Anllo EM, Ingrand P, Gil M, Neau JP, Ornon C, Bonnaud V. Self-consciousness and Alzheimer’s disease. Acta Neurol Scand 2001: 104: 296–300. # Munksgaard 2001. Objectives – To propose a neuropsychological study of the various aspects of self-consciousness (SC) in Alzheimer’s disease. Methods – Forty-five patients with probable mild or moderate AD were included in the study. Severity of their dementia was assessed by the Mini Mental State (MMS). Fourteen questions were prepared to evaluate SC. Results – No (...) significant correlations were found between SC score and educational level, age, and duration of disease. A significant correlation was found between SC score and the severity of dementia, whereas frontal disturbances were just short of the significance threshold. The various aspects of SC were not impaired to the same degree. The most disturbed ones were awareness of cognitive deficiencies, moral judgements and prospective memory. The least disturbed aspects were awareness of identity and of mental representation of the body. Items relating to anosognosia and moral judgements were significantly correlated with the MMS score, whereas affective state, body representation disorders, prospective memory, and capacities for introspection were not related to the severity of the dementia. Consciousness of identity was sound, regardless of MMS score. Conclusions – AD clearly induces an heterogeneous impairment of SC. SC requires a convergence of many neural networks. In AD, neuronal alterations involve many cortical areas and information sent to the associative frontal cortex from memory, language and visuospatial areas is lacking or disturbed. Thus, the sequential order of successive stimuli cannot be maintained by the heteromodal associative cortex (dorsal convexity of the prefrontal cortex), and the supramodal associative cortex (located rostrally in the frontal lobes) is unable to provide reliable monitoring and assessment of simultaneous neural cognitive networks carrying insufficient and inadequate input. The core deficiency in AD patients might be impaired SC equated with the disability to maintain sequential and simultaneous ‘‘attention to life’’. The Self-Consciousness Questionnaire, a clinical scale providing multidimensional measurement, indicates that different aspects of consciousness are not correlated with overall cognitive deficiency as determined by the MMSE. (shrink)

SummaryWe present a systematic discussion of the structural and conceptual simplifications of proofs of standard theorems afforded by nonstandard methods and examine to what extent the resulting nonstandard proofs satisfy the informal criterion of “plausibility”. We introduce the concept of a “standard detour” and show that all nonstandard proofs considered avoid such detours. Among the proofs examined are proofs of the Intermediate Value Theorem, the Riemann Integration Theorem, the Spectral Theorem for compact Hermitian operators, and the Arzela‐Ascoli Theorem.RésuméNous discutons systématiquement (...) les simplifications structurelles et conceptuelles apportées par des méthodes non standard aux démonstrations de théorèmes standard et examinons jusQuà quel point de telles démonstrations non standard satisfont à un critère informel de plausibilityé. Nous introduisons la notion de détour standard et montrons que toutes les démonstrations non standard considérées évitent de tels détours. Parmi les démonstrations examinées: celles du théoréme de la valeur intermédiate, du théorème ?on;intégration de Riemann, du théorème spectral pour les opérateurs hermitiques compacts et du théorème ?on;Arzelà‐Arcoli.ZusammenfassungWir stellen eine systematische Betrachtung der durch die Nichtstandard‐Methoden gegebe‐nen strukturellen und begrifflichen Vereinfachungen von Beweisen von Standardsätzen an, und untersuchen, wie weit die entstandenen Nichtstandard‐Beweise das informelle Kriterium der Plausibilität erfüllen. Wir führen den Begriff eines Standard‐Umweges ein, und zeigen, dass alle betrachteten Nichtstandard‐Beweise solche Umwege vermeiden. Unter den betrachteten Beweisen befinden sich Beweise des Zwischenwertsatzes, des Riemannschen lntegralsatzes, des Spektralsatzes für kompakte, hermitische Operatoren, und des Theorems von Arzelà‐Ascoli. (shrink)

When Kepler concluded that the orbit of Mars was not a circle, he was led to the belief that the orbit was an oval touching the circle at the apsides and lying within the circle at other points. In the definition of the oval, physical hypotheses played a primary role. Two forces were involved; a tractive force arising from the effect of the solar rays rotating with the sun, and a directing force arising from a natural instinct of the planet (...) itself. The former pushed the planet along the orbit while the latter enabled the planet to steer itself across the stream of the solar vortex in a small epicycle. In adopting this physical theory to determine the oval, Kepler was led into what he himself described as ‘a new labyrinth’. After several attempts to construct the oval, and by progressively eliminating the sources of error from his calculating procedures in order to arrive at an accurate mathematical formulation of the physical hypotheses, he was able to conclude that the oval was inconsistent with the empirical data and the physical theory in need of modification. (shrink)

Soon after receiving Bouvet's interpretation of the hexagrams of the I ching as binary numbers, Leibniz communicated this application of his binary arithmetic to Hans Sloane in a letter published here for the first time. The letter also included a report on the observations of the variable star in the neck of the Swan by Gottfried Kirch. Sloane sent a copy of the scientific parts of the letter to Flamsteed.

When Bouvet discovered the relationship between the binary arithmetic of Leibniz and the hexagrams of the I ching—in reality only a purely formal correspondence—he sent to Leibniz a woodcut diagram of the Fu-Hsi arrangement, which provides the key to the analogy. This diagram, in a re-drawn version, was first published by Gorai Kinzō in a study of Leibniz's interpretation of the I ching and Confucianism which has been influential in providing, indirectly, the principal source for the accounts of Wilhelm and (...) Needham. Yet this pioneering study of Leibniz's interpretation of the hexagrams is virtually unknown. Even the account of Needham, who saved it from complete obscurity, contains one or two inaccuracies about it and these are repeated by Zacher in his otherwise excellent monograph on Leibniz's binary arithmetic. (shrink)