Wittgenstein y la hipótesis del espectro visual invertido

Un caso de inversión peligrosa del espectro visual es aquél en el que dos personas tienen impresiones visuales distintas cuando ven el mismo objeto y sin embargo coinciden al afirmar que el objeto es, por ejemplo, rojo. De acuerdo con Ned Block, si los casos de inversión del espectro visual son concebibles, entonces puede construirse un argumento a favor de la existencia de los qualia: si dos sujetos tienen distintas impresiones visuales, entonces deben estar diciendo cosas distintas cuando profieren "esto es rojo" al describir su modo de ver el mismo objeto. Según Block, Wittgenstein se comprometió con la posibilidad de un tipo de inversión del espectro visual que permite defender la existencia de los qualia y, sin embargo, Wittgenstein parece oponerse a la idea de los qualia, luego hay una incoherencia en su pensamiento. Nuestra tesis en este trabajo es que el argumento de Block no es un problema para la posición de Wittgenstein con respecto al significado de los términos relativos a la percepción y que tal incoherencia en su pensamiento es solo aparente. TITLE: Wittgenstein and the Inverted Spectrum HypothesisABSTRACTA case of dangerous inverted spectrum is that one in which two subjects have different impressions when they see the same object and both claim, for example, that the object is red. According to Ned Block, if cases of dangerous inverted spectrum are conceivable, then we can offer an argument in favour of existence of qualia: two subjects with inverted spectrum don’t mean the same when they utter that the object is red. According to Block, Wittgenstein accepted the possibility of a kind of case of inverted spectrum that allows to defend the existence of qualia, and nevertheless Wittgenstein seems to be opposed to the idea of qualia. There is thus, it seems, an incoherence in the Wittgensteinian thought. Our thesis in this paper is that Wittgensteinian’ discussion about the inverted spectrum hypothesis is a particular discussion about the grammar of perceptual terms that pretends to show the irrelevance of our sensations in determining the meaning of perceptual terms. From this interpretation, the discussion of a case of inverted spectrum does not mean the commitment with the possibility of that case, and then such incoherence on Wittgenstein’ thought is only apparent.

Cerebellar dysfunction, cognitive flexibility and autistic traits in a non-clinical sample

Cerebellar dysfunction and impaired cognitive flexibility are key features of autism spectrum disorders (ASD). However, despite the increasing interest in subclinical autism, no research has yet examined the relationship between these signs and autistic traits in the wider population. This study used the Autism-Spectrum Quotient (AQ) questionnaire to assess autistic traits in university students enrolled in either systems-oriented or humanities degree programmes. Participants also completed a battery of motor tasks designed to assess cerebellar function, and subscales from the Delis–Kaplan Executive Function System (D-KEFS) battery. Students enrolled in systems-oriented degrees had on average higher AQ scores than students enrolled in humanities degrees. The data showed a significant correlation between autistic traits and motor function scores, as well as between autistic traits and verbal set-shifting ability, as assessed on the D-KEFS. These data provide support for the autistic spectrum hypothesis, in indicating that key cognitive, neurological and behavioural features of autism carry over into non-clinical populations.

Pathological gambling and compulsive buying: do they fall within an obsessive-compulsive spectrum?

Both compulsive buying (CB) and pathological gambling (PG) have been proposed as members of a spectrum of disorders related to obsessive-compulsive disorder (OCD). The spectrum hypothesis originated in the early 1990s and has gained considerable support, despite the lack of empirical evidence. Interest in this hypothesis has become critical because some investigators have recommended the creation of a new category that includes these disorders in DSM-5, now under development. In this article, the authors describe the origin of the obsessive-compulsive (OC) spectrum and its theoretical underpinnings, review both CB and PG, and discuss the data both in support of and against an OC spectrum. Both disorders are described in terms of their history, definition, classification, phenomenology family history, pathophysiology, and clinical management. The authors conclude that: (i) CB and PG are probably not related to OCD, and there is insufficient evidence to place them within an OC spectrum in DSM-V; (ii) PG should stay with the impulse-control disorders (ICDs); and (iii) a new diagnosis of CB should be created and be classified as an ICD.

Extending the spectrum idea: child personality, parenting and psychopathology

The spectrum hypothesis, postulating that differences between referred and non‐referred samples are confined to mean level differences, is elaborated by exploring whether the covariation between child problem behaviour and its predictors—child personality and parenting, rated by mothers—is similar in referred (N = 205) and non‐referred (N = 596) children and whether personality by parenting interactions can be generalized across samples. Results showed significant mean level differences for all the variables. Both personality and parenting explained problem behaviour, with some differences in strength of the effects across samples. Parenting by personality interactions mainly predicted externalizing behaviour, with benevolence and conscientiousness as the most prominent moderators. Results confirmed that moderators of problem behaviour operate similarly in the two samples, thus corroborating the spectrum hypothesis. Copyright © 2006 John Wiley & Sons, Ltd.

NONUNITAL SPECTRAL TRIPLES ASSOCIATED TO DEGENERATE METRICS

We show that one can define (p,∞)-summable spectral triples using degenerate metrics on smooth manifolds. Furthermore, these triples satisfy Connes–Moscovici's discrete and finite dimension spectrum hypothesis, allowing one to use the Local Index Theorem [1] to compute the pairing with K-theory. We demonstrate this with a concrete example.

Space–time Antarctic surface mass-balance variability from climate models

The interannual to interdecadal variability and space–time statistics (including radius of decorrelation) of the Antarctic surface mass balance (SMB) are evaluated from climate models and meteorological analyses. At model resolution scales (>100 km), the interannual relative standard deviation of precipitation ranges from ∼5% (remotest interior) to ∼40% and possibly more. Time variability is spatially coherent at distances of ∼500km on average, less than 300 km in the interior near ridges, but in excess of 700 km in some regions. As far as spatial distributions are concerned, interannual statistics can be broadly transposed to interdecadal time-scales. The amplitude of variability may also be extrapolated across time-scales, using a ‘white’ spectrum hypothesis according to one coupled ocean– atmosphere model, but a significantly ‘red’ spectrum hypothesis according to another. Surface sublimation and blowing-snow processes are estimated to have limited contributions to the statistics of the SMB at model-resolved scales. Precipitation statistics can thus largely be transposed to SMB. The information reported here is expected to be useful for defining the details of field programmes such as the International Trans-Antarctic Scientific Expedition (ITASE), for extrapolating the spatial significance of field SMB data and for better interpreting Antarctic ice-sheet surface elevation changes from satellite altimetry.

Empirically based subgrouping of eating disorders in adolescents: A longitudinal perspective

BackgroundSuccessive DSM versions struggle with the heterogeneity of the eating disorders. Criteria were mainly based on clinical impressions and on descriptive and inferential studies.MethodIn a study of 55 eating-disordered adolescents, we investigated whether patients could be grouped on an empirical basis, using principal components analysis (PCA) with optimal scoring (scaling), i.e. PCA with no a priori assumptions. Clustering was based on Morgan-Russell subscales, each measured four times over the course of illness.ResultsContrary to DSM – IV criteria, patients did not cluster primarily on the basis of anorectic symptoms; the occurrence of bulimic symptoms was more dominant. Core symptomatology (preoccupation with food, disturbed body perception and inadequate sexual behaviour) did not differ between patients, either at referral or over time.ConclusionsThese results support the spectrum hypothesis of the eating disorders, which considers them as one syndrome with different manifestations.

The Intelligibility of Spectrum Inversion

Christopher Peacocke has recently made an important and insightful effort to fashion a non-verificationist method for distinguishing sense from nonsense (or, as he puts it, genuine from spurious hypotheses). The argument is subtle and complex, and varies somewhat with each of his three target ‘spurious hypotheses’: that if a perfect fission of one person into two were to occur, one and only one of the resulting persons would be identical with the original; that another person’s visual experience can be qualitatively different from your own when you are both seeing the same object, even though your relevant brain states are physically identical and so are your environmental conditions; and that the entire material universe is moving undetectably at a particular uniform velocity with respect to absolute space. My own assessment of his efforts is that they are most successful against the third of these hypotheses, and that this is a function of the fact that of the three, it alone (from both Peacocke’s and my perspectives) clearly employs a problematic concept- that of absolute location. However, my purpose here is not to engage in a comprehensive evaluation of Peacocke’s project; it is rather to defend the extreme inverted spectrum hypothesis (henceforth EISH) against his attack. I shall argue not only that his argument against EISH fails, but that he is himself independently committed to its intelligibility. Beyond that, I shall point out some striking and, to my mind, welcome consequences of his plausible claims concerning the relations between his own proposal and certain other views concerning content theory; the consequences in question depend both on his positive proposal and on my reasons for rejecting his argument against the extreme inversion hypothesis.