Belief contraction without recovery

The postulate of recovery is commonly regarded to be the intuitively least compelling of the six basic Gärdenfors postulates for belief contraction. We replace recovery by the seemingly much weaker postulate of core-retainment, which ensures that if x is excluded from K when p is contracted, then x plays some role for the fact that K implies p. Surprisingly enough, core-retainment together with four of the other Gärdenfors postulates implies recovery for logically closed belief sets. Reasonable contraction operators without recovery do not seem to be possible for such sets. Instead, however, they can be obtained for non-closed belief bases. Some results on partial meet contractions on belief bases are given, including an axiomatic characterization and a non-vacuous extension of the AGM closure condition.     

Time to retire the concept of brand personality? Extending the critique and introducing a new framework

In consumer behaviour literature, there is a growing concern about the construct validity of brand personality. We extend this critique and introduce a new approach for the conceptualisation and measurement of human brand associations (HBA). A qualitative study of free associations to six brands in different categories and cultures reveals that brand personality traits, as defined in the literature, are practically non‐existent in real associative networks for brands. The responses are, however, in line with the new HBA framework. The findings suggest that consumer researchers should retire the concept of brand personality and use the new approach instead.     

Coherentist Contraction

A model of coherentist belief contraction is constructed. The outcome of belief contraction is required to be one of the coherent subsets of the original belief set, and a set of plausible properties is proposed for this set of coherent subsets. The contraction operators obtained in this way are shown to coincide with well-known belief base operations. This connection between coherentist and foundationalist approaches to belief change has important implications for the philosophical interpretation of models of belief change.     

Functional brain imaging as a looking-glass into the degraded brain: reviewing evidence from Alzheimer disease in relation to normal aging

Research on the real-time relationship between brain activity and mental performance is intense. However, relatively few studies have been devoted to patients with different diseases or lesions. Such studies may cast light on certain aspects of brain activity, such as plasticity. This review summarizes studies on Alzheimer's disease (AD) patients where the techniques to map brain activity in relation to mental performance have been utilized. Research findings suggest, that there is a spectrum of changes in AD patients that is distinct from that seen in healthy aging. These changes include: (i) loss of activated regions, (ii) reduced activation possibly due to brain degeneration typical of AD, (iii) the emergence of newly activated regions in order to compensate for minor brain deterioration (e.g., an enlargement of activated regions sometimes manifested as an increased bilaterality or a hemispheric shift of activation, and dedifferentiation), (iv) decreased level of activation, and (v) no change at all, which may occur in easy tasks or tasks that do not involve regions exposed to brain atrophy. In conclusion, the pattern of activation in AD depends on interactions between the clinical stage of patients, and the pattern of brain degeneration, as well as the task difficulty and specific networks necessary for solving the task.     

Welfare,Justice, and Pareto Efficiency

In economic analysis, it is usually assumed that each individuals well-being (mental welfare) depends on her or his own resources (material welfare). A typology is provided of the ways in which one persons well-being may depend on the material resources of other persons. When such dependencies are taken into account, standard Paretian analysis of welfare needs to be modified. Pareto efficiency on the level of material resources need not coincide with Pareto efficiency on the level of well-being. A change in economic conditions that is Pareto efficient in the standard sense, i.e., with respect to material resources, may nevertheless sacrifice one persons well-being to that of another. It is shown that under plausible assumptions, Pareto efficiency on the level of well-being may require the reduction of inequality on the level of material resources.     

Global and Iterated Contraction and Revision: An Exploration of Uniform and Semi-Uniform Approaches

In order to clarify the problems of iterated (global) belief change it is useful to study simple cases, in particular consecutive contractions by sentences that are both logically and epistemically independent. Models in which the selection mechanism is kept constant are much more plausible in this case than what they are in general. One such model, namely uniform specified meet contraction, has the advantage of being closely connected with the AGM model. Its properties seem fairly adequate for the intended type of contraction. However, the revision operator based on it via the Levi identity collapses into an implausible operation that loses all old information when revising by new information. A weaker version, semi-uniform specified meet contraction, avoids the collapse but has the disadvantage of a remarkably weak logic. It is left as an open issue whether there is an intermediate class of contraction operators that yields a more satisfactory logic.     

Similarity semantics and minimal changes of belief

Different similarity relations on sets are introduced, and their logical properties are investigated. Close relationships are shown to hold between similarity relations that are based on symmetrical difference and operators of belief contraction that are based on relational selection functions. Two new rationality criteria for minimal belief contraction, the maximizing property and the reducing property, are proposed.     

Sexual Debut Ages in Heterosexual,Lesbian, Gay,and Bisexual Young Adults in Norway

This study estimates sexual debut ages in young heterosexual, lesbian, gay, and bisexual men and women in Norway. A questionnaire survey was completed online by 27.2 % of a representative national web sample of 2090 persons aged 18–29 years. Three self-selected samples of 924 respondents completed an extended version of the survey online. Lesbian and bisexual women reported earlier experience of orgasm through masturbation than heterosexual women (median 13.1 vs. 15.2 years), and heterosexual men (median 13.5) reported earlier debut than heterosexual women. There was a statistically significant difference between heterosexual and lesbian and bisexual women’s age at the first experience of receptive vaginal sex (median 16.8 vs. 15.4 years). As regards experience of insertive vaginal sex, a significantly higher percentage of heterosexual men than women, and of heterosexual and lesbian and bisexual women, reported experience. It was more common among lesbian and bisexual women than heterosexual women to have had oral sex with another woman, but in neither group did the cumulative percent reach 50 % by the age of 29 years and the median could not be estimated. Gay and bisexual men reported earlier receptive anal sex debut than heterosexual men. With regard to insertive anal sex, gay and bisexual men accumulated experience earlier than heterosexual men, and lesbian and bisexual women acquired this experience earlier than heterosexual women. Compared to heterosexuals, LGB persons of both genders engage in more varied sexual activities. Lesbian and gay persons have same-sex experiences at an earlier age than bisexuals.     

Health‐adjusted neuropsychological test norms based on 463 older Swedish car drivers

There is a need for improved normative information in particular for older persons. The present study provides neuropsychological test norms on seven cognitive tests used in a sample representing the general older driving population, when uncontrolled and controlled for physical health. A group of 463 healthy Swedish car drivers, aged 65 to 84 years, participated in a medical and neuropsychological examination. The latter included tests of visual scanning, mental shifting, visual spatial function, memory, reaction time, selective attention, and simultaneous capacity. Hierarchical regression analyses demonstrated that, when uncontrolled for health, old age was associated with significant impairment on all seven tests. Education was associated with a significant advantage for all tests except most reaction time subtests. Women outperformed men on selective attention. Controlling for health did not consistently change the associations with education, but generally weakened those with age, indicating rises in normative scores of up to 0.36 SD (residual). In terms of variance explained, impaired health predicted on average 2.5%, age 2.9%, education 2.1% and gender 0.1%. It was concluded (1) that individual regression‐based predictions of expected values have the advantage of allowing control for the impact of health on normative scores in addition to the adjustment for various demographic and performance‐related variables and (2) that health‐adjusted norms have the potential to classify functional status more accurately, to the extent that these norms diverge from norms uncontrolled for physical health.