What Is Rational About Nash Equilibria?

Nash Equilibrium is a central concept ingame theory. It has been argued that playing NashEquilibrium strategies is rational advice for agentsinvolved in one-time strategic interactions capturedby non-cooperative game theory. This essaydiscusses arguments for that position: vonNeumann–Morgenstern's argument for their minimaxsolution, the argument from self-enforcingagreements, the argument from the absence ofprobabilities, the transparency-of-reasons argument,the argument from regret, and the argument fromcorrelated equilibrium. All of these argumentseither fail entirely or have a very limited scope.Whatever the use of Nash Equilibrium is, therefore,it is not useful as a rational recommendation inone-time strategic interactions. This is good newsfor Bayesians: although this discussion does notargue directly for the Bayesian idea of rationalityas expected utility maximization, it argues againsta position that has been regarded as a contender insituations of strategic interaction.     

Loneliness and solitude in adolescence: A confirmatory factor analysis of alternative models

The present study tested a four-factor model of adolescent loneliness and solitude that comprises peer-related loneliness, family loneliness, negative attitude toward solitude, and positive attitude toward solitude. Nine different instruments for a total of 14 scales and derivative subscales were completed by a sample of mid-adolescents (N = 534) from Grades 10 through 12 (aged 15–18 years) in the Dutch-speaking part of Belgium. As expected, the four-factor solution provided a better fit to the data than did alternative models that comprised just a single factor, or two and three factors. Use of the Loneliness and Aloneness Scale for Children and Adolescents (LACA) is recommended, because the instrument measures all four aspects of the model. Implications for current theories on adolescent loneliness and associated phenomena, such as adolescents’ attitude toward being on their own, are briefly discussed.     

Latent Classes of Dysregulated Behaviors Relate to Negative Mental Images

Dysregulated behaviors (DBs), such as self-harm or binge eating, are related to various negative outcomes. In this study, we investigate how classes of individuals vary in their level of DBs. We compare the classes with regards to their experiences regarding negative mental images and emotion regulation strategies. A web-based survey assessed eleven DBs in a sample of N=912 adults. A latent class analysis (LCA) identified a class of 168 adults that were prone to various DBs (“high(DBs)”). Another class (n?=?46) reported drunkenness and risks for drug use and overeating (“high(Intake)”). The majority of individuals (n?=?698) featured a low rate of DBs (“low(DBs)”). The high(DBs) exhibited the highest scores in distressing imagery and maladaptive emotion regulation. The high(Intake) had a low overall profile; however, it displayed increased imagery nowness. Class differences were leveled by depressive symptoms. The findings help extend the knowledge on DBs and their correlates. Clinical implications are discussed.     

The revelation effect: A meta-analytic test of hypotheses

Judgments can depend on the activity directly preceding them. An example is the revelation effect whereby participants are more likely to claim that a stimulus is familiar after a preceding task, such as solving an anagram, than without a preceding task. We test conflicting predictions of four revelation-effect hypotheses in a meta-analysis of 26 years of revelation-effect research. The hypotheses’ predictions refer to three subject areas: (1) the basis of judgments that are subject to the revelation effect (recollection vs. familiarity vs. fluency), (2) the degree of similarity between the task and test item, and (3) the difficulty of the preceding task. We use a hierarchical multivariate meta-analysis to account for dependent effect sizes and variance in experimental procedures. We test the revelation-effect hypotheses with a model selection procedure, where each model corresponds to a prediction of a revelation-effect hypothesis. We further quantify the amount of evidence for one model compared to another with Bayes factors. The results of this analysis suggest that none of the extant revelation-effect hypotheses can fully account for the data. The general vagueness of revelation-effect hypotheses and the scarcity of data were the major limiting factors in our analyses, emphasizing the need for formalized theories and further research into the puzzling revelation effect.     

A guideline for integrating dynamic areas of interests in existing set-up for capturing eye movement: Looking at moving aircraft

Today, capturing the behavior of a human eye is considered a standard method for measuring the information-gathering process and thereby gaining insights into cognitive processes. Due to the dynamic character of most task environments there is still a lack of a structured and automated approach for analyzing eye movement in combination with moving objects. In this article, we present a guideline for advanced gaze analysis, called IGDAI (Integration Guideline for Dynamic Areas of Interest). The application of IGDAI allows gathering dynamic areas of interest and simplifies its combination with eye movement. The first step of IGDAI defines the basic requirements for the experimental setup including the embedding of an eye tracker. The second step covers the issue of storing the information of task environments for the dynamic AOI analysis. Implementation examples in XML are presented fulfilling the requirements for most dynamic task environments. The last step includes algorithms to combine the captured eye movement and the dynamic areas of interest. A verification study was conducted, presenting an air traffic controller environment to participants. The participants had to distinguish between different types of dynamic objects. The results show that in comparison to static areas of interest, IGDAI allows a faster and more detailed view on the distribution of eye movement.     

Judging the animacy of words: The influence of typicality and age of acquisition in a semantic decision task

The age at which members of a semantic category are learned (age of acquisition), the typicality they demonstrate within their corresponding category, and the semantic domain to which they belong (living, non-living) are known to influence the speed and accuracy of lexical/semantic processing. So far, only a few studies have looked at the origin of age of acquisition and its interdependence with typicality and semantic domain within the same experimental design. Twenty adult participants performed an animacy decision task in which nouns were classified according to their semantic domain as being living or non-living. Response times were influenced by the independent main effects of each parameter: typicality, age of acquisition, semantic domain, and frequency. However, there were no interactions. The results are discussed with respect to recent models concerning the origin of age of acquisition effects.     

Impulsive and premeditated subtypes of aggression in conduct disorder: differences in time estimation

Research aimed at identifying and studying subtypes of aggression have historically dichotomized aggressive subtypes, although specific nomenclature has varied; one approach has been to classify aggressive behavior as predominantly impulsive or predominantly premeditated. There are a number of behavioral and cognitive differences between those exhibiting these different forms of aggression. This study was designed to extend understanding of the impulsive/premeditated aggression dichotomy by comparing time estimation among adolescents exhibiting predominantly impulsive or predominantly premeditated forms of physical aggression who have a psychiatric diagnosis of conduct disorder (CD). Time estimation has previously been shown to be disrupted in impulsive and some aggressive individuals. Time estimation was compared between healthy Controls (n = 37) and two groups of adolescents with CD, those with histories of either predominantly impulsive (CD-Impulsive, n = 26) or predominantly premeditated (CD-Premeditated, n = 38) aggressive behaviors. Participants completed five computerized trials during which they estimated when 1 min had passed. Among aggressive adolescents with CD, the misperception of time was specific to those with histories of impulsive aggression, although time estimates improved with repeated testing and performance feedback. This study confirms the importance of considering the role and type of physical aggression when studying heterogeneous diagnostic groups like CD and supports the relevance of time estimation to certain subgroups of adolescents with CD.     

Mindestanforderungen für Schuldfähigkeitsgutachten*

Ohne Zusammenfassung Wegen der besonderen Bedeutung für die Bemühungen um die Qualit?tssicherung in den forensischen Disziplinen wird der folgende Artikel, entstanden aus einer interdisziplin?ren Diskussion am BGH, hier nochmals den Fachkollegen zur Kenntnis gegeben. H. Sa? * bereits 2005 erschienen in NStZ 25:57–62     

Investigating information seeking in ravens (Corvus corax)

Animal Cognition - Measuring the responses of non-human animals to situations of uncertainty is thought to shed light on an animal’s metacognitive processes; namely, whether they monitor...