The puzzle of language evolution

Linguistics must again concentrate on the evolutionary nature of language, so that language models are more realistic with respect to human natural languages and have a greater explanatory force. Multi-agent systems are proposed as a possible route to develop such evolutionary models and an example is given of a concrete experiment in the origins and evolution of word-meaning based on a multi-agent approach.     

Knowledge level learning and the power law: A soar model of skill acquisition in scheduling

Zusammenfassung. Das hier vorgestellte Modell lernt graduell, Planungsaufgaben aus der Klasse der Maschinenbelegungsprobleme (job-shop-scheduling problems) zu lösen. Mit Hilfe des Chunking-Mechanismus von Soar wird episodisches Wissen über die Belegungsreihenfolge von Aufträgen auf Maschinen memoriert. Bei der Entwicklung des Modells wurden zahlreiche qualitative (z. B. Transfereffekte) und quantitative Befunde (z. B. Bearbeitungszeiten) aus einer früheren empirischen Untersuchung berücksichtigt. In einer Validierungsstudie wurden dieselben Aufgaben von 14 Probanden und dem Modell bearbeitet. Die Passung von Simulationsdaten und empirischen Ergebnissen fiel insgesamt gut aus. Allerdings löst das Modell die Aufgaben schneller und zeigt auch einen etwas besseren Lernverlauf als die Probanden. Das Modell liefert eine Erklärung für das Rauschen, das typischerweise bei Bearbeitungszeiten zu beobachten ist: es handelt sich um erworbenes Wissen, das mehr oder weniger gut und auch unterschiedlich häufig auf neue Situationen übertragen wird. Der Lernverlauf der Probanden entspricht nur für aggregierte Daten einer Potenzfunktion (power law). Der vorgestellte Mechanismus zeigt, wie ein symbolisches Modell der Informationsverarbeitung graduelle Verhaltensänderungen generiert und wie der offensichtliche Erwerb allgemeiner Prozeduren ohne explizites Lernen von deklarativen Regeln erfolgen kann. Es wird nahegelegt, daß es sich hier um die Modellierung einer Form impliziten Lernens handelt. Summary. The model presented here gradually learns how to perform a job-shop scheduling task. It uses Soar's chunking mechanism to acquire episodic memories about the order to schedule jobs. The model was based on many qualitative (e.g., transfer effects) and quantitative (e.g., solution time) regularities found in previously collected data. The model was tested with new data where scheduling tasks were given to the model and to 14 subjects. The model generally fit these data with the restrictions that the model performs the task (in simulated time) faster than the subjects, and its performance improves somewhat more quickly than the subjects' performance. The model provides an explanation of the noise typically found in problem solving times - it is the result of learning actual pieces of knowledge that transfer more or less to new situations but rarely by an average amount. Only when the data are averaged (i.e., over subjects) does the smooth power law appear. This mechanism demonstrates how symbolic models can exhibit a gradual change in behavior and how the apparent acquisition of general procedures can be performed without resorting to explicit declarative rule generation. We suggest that this may represent a type of implicit learning.     

Further evidence on the effects of symbolic distance on Stroop-like interference

Pavese and Umiltà found that, in an enumeration task, Stroop-like interference is larger when the digit identity is symbolically close to the enumeration response than when it is symbolically far. In two experiments testing 49 undergraduates, we further explored this phenomenon using Francolini and Egeth's paradigm. We found that symbolic distance affected interference even when the stimulus was briefly presented and masked. In Exp. 2, which tested numerosities outside the subitizing range, individuals used a different enumeration strategy but showed the same symbolic distance effect. These results support the hypothesis that Stroop interference found in enumeration tasks depends on a rapid and automatic activation of digits' magnitude representation. Received: 10 November 1997 / Accepted: 23 June 1998     

Husserl and queer theory

In spite of a history wherein queer theory has openly rejected phenomenology, phenomenology has gained increasing interest amongst queer theorists. However, Husserl’s phenomenology is often marginalized in attempts to integrate queer theory with phenomenology, and when Husserl is addressed specifically, his work is often treated superficially or even misrepresented. Given this, my first goal is to demonstrate how Husserl’s work is already open to positions considered fundamental to queer theory, and that Husserl is often explicitly arguing for these positions himself. In doing so, I wish to show that Husserl’s phenomenology is well fitted for complementary engagement with queer theory. My second goal is to work through some ways in which Husserl’s phenomenology and queer theory can work together in detail to accomplish shared theoretical goals. Although this will not be a full-blown analysis—which would exceed the parameters of this article—my hope is to provide a certain amount of in depth work that can then assist further analyses that combine these methods.     

Partiality and distributive justice in African bioethics

African ethical theories tend to hold that moral agents ought to be partial, in the sense that they should favour members of their family or close community. This is considered an advantage over the impartiality of many Western moral theories, which are regarded as having counterintuitive implications, such as the idea that it is unethical to save a family member before a stranger. The partiality of African ethics is thought to be particularly valuable in the context of bioethics. Thaddeus Metz, in particular, argues that his African-derived theory best accounts for a number of plausible intuitions, such as the intuition that health care practitioners ought to be biased towards the patients for whom they are directly responsible. In this article, I claim that the plausible intuitions drawn on in favour of partiality can be satisfactorily explained on the basis of impartial moral theories. Moreover, I argue that blanket acceptance of partiality has problematic consequences for distributive justice in resource allocation in biomedical contexts. By contrast, impartial theories can justify plausible instances of partiality whilst avoiding the pitfalls of fully partial moral theories. Although this provides grounds for abandoning partiality in principle, I claim that this finding should not be seen as damaging to African medical ethics. Instead, it prompts investigation of underexplored possibilities of impartial African moral theories. To demonstrate the value of this direction, I sketch some novel and attractive conceptions that combine impartiality with elements of African ethics.     

Capuchins (<Emphasis Type="Italic">Cebus apella</Emphasis>) fail to show an asymmetric dominance effect

The asymmetric dominance effect (ADE) occurs when the introduction of a partially dominated decoy option increases the choice share of its dominating alternative. The ADE is a violation of regularity and the constant-ratio rule, which are two derivations of the independence of irrelevant alternatives axiom, a core tenant of rational choice. The ADE is one of the most widely reported human choice phenomena, leading researchers to probe its origins by studying a variety of non-human species. We examined the ADE in brown capuchin monkeys (Cebus apella), a species that displays many other decision biases. In Experiment 1, we used a touchscreen method to elicit choice-based preferences for food rewards in asymmetrically dominated choice sets. In Experiments 2 and 3, we distinguished between different types of judgments and used a free selection task to elicit consumption-based preferences for juice rewards. However, we found no evidence for the ADE through violations of regularity or the constant-ratio rule, despite the similarity of our stimuli to other human and non-human experiments. While these results appear to conflict with existing literature on the ADE in non-human species, we point out methodological differences—notably, the distinction between value-based and perception-based stimuli—that have led to a collection of phenomena that are difficult to understand under a unitary theoretical framework. In particular, we highlight key differences between the human and non-human research and provide a series of steps that researchers could take to better understand the ADE.