SUBJECTIVISM,UTILITY, AND AUTONOMY

Taking as a starting point a thesis of David Gauthier's about the status of Rational Choice Theory. I discuss the relation between a subjectivist theory of value and an account of rational agency that leaves room for autonomy. I argue that if autonomy presupposes an activity of practical reason, the maximization of subjective expected utility (as prescribed by Rational Choice Theory) cannot serve as the principle of practical reason.     

The role of strategies in deciding advantageously in ambiguous and risky situations

In decision situations of everyday life, the potential positive or negative consequences of a decision are often specified and the associated probabilities are known or they are principally calculable ("decisions under risk"). On the basis of correlations reported in patient studies, it has been recently proposed that decisions under risk involve strategic components, i.e. calculation of the risk, as well as emotional processes, i.e. processing feedback from previous decisions. However, the potential impact of calculative strategies on decision-making under risk has not been investigated systematically, so far. In the current study, we examined 42 healthy subjects (21 females) with the Game of Dice Task measuring decisions under risk, and a questionnaire assessing strategy application in items comparable to the choices in the Game of Dice Task. In addition, the subjects performed the Iowa Gambling Task, examining decision-making under ambiguity, and a neuropsychological test battery focusing on executive functions. Results indicate that deciding advantageously in a decision-making task with explicit and stable rules is linked to applying calculative strategies. In contrast, individuals who decide intuitively prefer risky or disadvantageous choices in the Game of Dice Task. Applying calculative strategies was correlated with executive functions but not with performance on the Iowa Gambling Task. The results support the view that calculative processes and strategies may improve decision-making under explicit risk conditions.     

The Secret of My Success

In an information state where various agents have both factual knowledge and knowledge about each other, announcements can be made that change the state of information. Such informative announcements can have the curious property that they become false because they are announced. The most typical example of that is ‘fact p is true and you don’t know that’, after which you know that p, which entails the negation of the announcement formula. The announcement of such a formula in a given information state is called an unsuccessful update. A successful formula is a formula that always becomes common knowledge after being announced. Analysis of information systems and ‘philosophical puzzles’ reveals a growing number of dynamic phenomena that can be described or explained by unsuccessful updates. This increases our understanding of such philosophical problems. We also investigate the syntactic characterization of the successful formulas. An erratum to this article is available at .     

Beyond Recovery? a Reply to Tennant

In his paper ‘Changing the Theory of Theory Change: Reply to My Critics’, N. Tennant (1997b) reacts to the critical reception of an earlier article of his. The present note rectifies some of the most serious misrepresentations in Tennant's reply. This revised version was published online in July 2006 with corrections to the Cover Date.     

Visuo-Spatial Working Memory Span: A Sensitive Measure of Cognitive Deficits in Children With ADHD

Working memory (WM) has been hypothesised to be impaired in attention-deficit/hyperactivity disorder (ADHD). However, there are few studies reported on tests measuring visuo-spatial WM (VSWM) in ADHD. Some of these studies used paradigms including episodic memory, others only used low memory loads. In the present study we used a VSWM test that has not been used previously in ADHD research. The sensitivity of the VSWM test and a choice reaction time (CRT) test was evaluated in a pilot study by comparing them to two commonly used tests in ADHD-research; the Continuous Performance Test (CPT) and a Go/no-go test, in children with and without ADHD. The groups differed significantly in performance on the VSWM test (P<.01) and CRT (P<.05) but not on the CPT (P>.1) or on the Go/no-go test (P>.1). The results from the VSWM and CRT tests were replicated in a larger sample of participants (80 boys; 27 boys with ADHD and 53 controls, mean age 11.4 years). The difference between the groups was significant for both the VSWM test (P<.01) and the CRT test (P<.01). The effect size (ES) of the VSWM test was 1.34. There was a significant age-by-group interaction on the VSWM test, with larger group differences for the older children (P<.01). Our results show that the VSWM test is a sensitive measure of cognitive deficits in ADHD and it supports the hypothesis that deficits in VSWM is a major component of ADHD.