Naive and refined truth approximation

The naive structuralist definition of truthlikeness is an idealization in the sense that it assumes that all mistaken models of a theory are equally bad. The natural concretization is a refined definition based on an underlying notion of structurelikeness.In Section 1 the naive definition of truthlikeness of theories is presented, using a new conceptual justification, in terms of instantial and explanatory mistakes.In Section 2 general constraints are formulated for the notions of structurelikeness and truthlikeness of structures.In Section 3 a refined definition of truthlikeness of theories is presented, based on the notion of structurelikeness, using a sophisticated version of the conceptual justification for the naive definition.In Section 4 it is shown that idealization and concretization is a special kind of potentially refined truth approximation.I would like to acknowledge that van Benthem (1987) played in several respects a crucial role in the research for a new refined definition. Moreover, I like to thank David Miller, Ilkka Niiniluoto, and two referees for their comments on an earlier version. One of the referees notes that the Miller version of the naive approach (in model-theoretic terms, and identifying the truth with the truth about the actual world) has been criticised on several occasions for its failure to accommodate likeness between structures by Oddie (notably Oddie, 1986). The idea that likeness between structures should be a guiding idea behind truthlikeness is said to be a constant theme of Oddie's work. All this may well be true, but I should add however that Oddie's publications did not play any role in my research. The local references to Oddie are based on the suggestions by the referee.     

Blind to Object Changes: When Learning the Same Object at Different Levels of Categorization Modifies Its Perception

The perceptual features people extract from objects depend on how they typically categorize them. It is now commonly acknowledged that the human perceiver can interact with the objects of his or her world at different, hierarchically organized levels of categorization. People who have learned to categorize an object as general or specific may therefore perceive different features in this object. We report two experiments that examined the hypothesis that the nature of categorization (general vs. specific) can influence the perceived properties of an identical distal object.     

TGF-β1 in Aplysia: Role in Long-Term Changes in the Excitability of Sensory Neurons and Distribution of TβR-II-Like Immunoreactivity

Exogenous recombinant human transforming growth factor β-1 (TGF-β1) induced long-term facilitation of Aplysia sensory-motor synapses. In addition, 5-HT-induced facilitation was blocked by application of a soluble fragment of the extracellular portion of the TGF-β1 type II receptor (TβR-II), which presumably acted by scavenging an endogenous TGF-β1-like molecule. Because TβR-II is essential for transmembrane signaling by TGF-β, we sought to determine whether Aplysia tissues contained TβR-II and specifically, whether neurons expressed the receptor. Western blot analysis of Aplysia tissue extracts demonstrated the presence of a TβR-II-immunoreactive protein in several tissue types. The expression and distribution of TβR-II-immunoreactive proteins in the central nervous system was examined by immunohistochemistry to elucidate sites that may be responsive to TGF-β1 and thus may play a role in synaptic plasticity. Sensory neurons in the ventral–caudal cluster of the pleural ganglion were immunoreactive for TβR-II, as well as many neurons in the pedal, abdominal, buccal, and cerebral ganglia. Sensory neurons cultured in isolation and cocultured sensory and motor neurons were also immunoreactive. TGF-β1 affected the biophysical properties of cultured sensory neurons, inducing an increase of excitability that persisted for at least 48 hr. Furthermore, exposure to TGF-β1 resulted in a reduction in the firing threshold of sensory neurons. These results provide further support for the hypothesis that TGF-β1 plays a role in long-term synaptic plasticity in Aplysia.     

Nature des représentations du langage écrit aux débuts de l'apprentissage de la lecture: un modèle interprétatif

The main objective of this study is to test a knowledge-based simulation model, elaborated in a previous longitudinal research in order to explain reading errors produced by first-grade children. This model relies on two assumptions: (1) in the beginning of the grapho-phonological acquisition, the child tries to extract, from the series of letters which forms a word, graphic patterns corresponding to an oral syllable; (2) these patterns are stored either in an ordered representation or in a non-ordered representation. Permutation errors, often pointed out in this phase of reading acquisition, would then be the mark of a non-ordered representation of the graphic patterns. Two experiments were proposed to new first-grade children, in the middle of the school year. In experiment 1, they had to detect an oral syllable in written pseudo-words in which the first trigram did or did not correspond to the legal order. In experiment 2, they had to read aloud trisyllabic pseudo-words in which the first trigram was presented in four different orders. Reading errors correspond to the predictions our model allows. Moreover, the absence of correlation between the two tasks suggests that the knowledge activated depends on the type of activity.     

Computers in psychology teaching in the U.K.

This paper describes the first year of operation of the CTI Centre for Psychology, which pro-motes the use of computers in psychology teaching in the U.K. We outline current use of computers in teaching and some of the obstacles to the effective development of computer-supported courses. In particular, we focus on the need for closer integration of innovative forms of teaching into courses. We describe the Centre’s strategy for supporting both conventional and innovative computer-supported teaching, and argue that effective use of software depends on both the instructional situation and the educational context.     

Relationships between early and final reports of treatment outcome in long-term group psychotherapy

A study of the report of treatment outcome in three long-term therapy groups focused on two questions: 1) Are early reports of treatment outcome significantly related to final reports, i.e., is there substantial consistency in outcome reports over the course of therapy? 2) Are final reports of treatment outcome significantly more favorable than early reports, i.e., do patients experience significant improvement after the early part of therapy? Affirmative answers to these two questions for a number of outcome variables led to a consideration of a number of clinical and research implications.     

Long-term outcome after discontinuation of benzodiazepines for insomnia: a survival analysis of relapse

Discontinuation of benzodiazepine (BZD) treatment for insomnia can be a difficult task. Cognitive-behavior therapy (CBT) for insomnia, combined with a supervised medication taper, can facilitate withdrawal but there is limited evidence on long-term outcome after discontinuation. The objective of this study was to examine medication-free survival time and predictors of relapse (i.e., resumed BZD hypnotics) over a 2-year period in 47 older adults (mean age 62.1 years) with persistent insomnia and prolonged BZD use (average duration of 18.9 years), who had successfully discontinued BZD following CBT for insomnia, a supervised medication taper program, or a combined approach. The Kaplan-Meier product-limit method was used to estimate survival time, defined as time between end-of-treatment and relapse or end of follow-up. By the end of the 24-month follow-up, 42.6% of the samples had resumed BZD use. Participants in the Combined (33.3%) and Taper (30.8%) groups relapsed significantly less than their counterparts from the CBT group (69.2%). Survival rates at 3 months were 61.5% (CBT), 100% (Taper), and 80.9% (Combined). At 12 months, they were 38.5%, 83.3%, and 70.8%, respectively; and, at 24 months, they were 28.9%, 64.8% and 64.9%, respectively. Mean survival time was significantly longer for both the Taper (18.6 months, SE = 2.1) and Combined groups (12.6 months, SE = 1.4), relative to the CBT group (8.5 months, SE = 1.8). Significant predictors of relapse included treatment condition, end of treatment insomnia severity, and psychological distress. In conclusion, there is a substantial relapse rate following BZD discontinuation among prolonged users. CBT booster sessions might enhance compliance with CBT and prove useful in preventing relapse.     

Reasoning, emotions, and delusional conviction in psychosis

The aim of the study was to elucidate the factors contributing to the severity and persistence of delusional conviction. One hundred participants with current delusions, recruited for a treatment trial of psychological therapy (PRP trial), were assessed at baseline on measures of reasoning, emotions, and dimensions of delusional experience. Reasoning biases (belief inflexibility, jumping to conclusions, and extreme responding) were found to be present in one half of the sample. The hypothesis was confirmed that reasoning biases would be related to delusional conviction. There was evidence that belief inflexibility mediated the relationship between jumping to conclusions and delusional conviction. Emotional states were not associated with the reasoning processes investigated. Anxiety, but not depression, made an independent contribution to delusional conviction.     

Controversies in counseling for mitochondrial conditions

A healthy woman sought preconceptional genetic counseling regarding a family history of a mitochondrial myopathy in her brother and retinitis pigmentosa (RP) in her two maternal aunts. Several questions were raised: (1) What is the likelihood of a familial mitochondrial condition? (2) What molecular tests or prenatal screening can we offer? (3) How would these tests help assess the likelihood of a familial mitochondrial condition? A mitochondrial mutation previously identified in the brother consisted of a heteroplasmic 2.9 kb deletion. We detected this deletion in the peripheral blood of the brother by PCR amplification of the deletion breakpoint, but not in his mother, the consultand, nor in one of the two aunts affected with RP. Although the molecular analysis was encouraging to the consultand, a familial mitochondrial disorder could not be eliminated with certainty. The pros and cons of prenatal testing for mitochondrial disorders are discussed in general, and as specifically related to this family.