Problem-solving in a cooperative task in peach-fronted conures (Eupsittula aurea)

Animal Cognition - Cooperation is a complex behaviour found in many kinds of organisms and occurs between individuals of the same and different species. Several studies have examined the...     

Cross-language computational investigation of the length effect in reading aloud

The authors examined whether 2 computational models of reading, the dual-route cascaded model (M. Coltheart, K. Rastle, C. Perry, R. Langdon, & J. C. Ziegler, 2001) and the connectionist 2-layer model (M. Zorzi, G. Houghton, & B. Butterworth, 1998), were able to predict the pattern that the length effect found in reading aloud is larger in German than in English (J. C. Ziegler, C. Perry, A. M. Jacobs, & M. Braun, 2001). The results showed that the dual-route cascaded model, which uses a serial mechanism for assembling phonology, successfully predicted this cross-language difference. In contrast, the connectionist model of Zorzi et al. (1998) predicted the opposite: a larger length effect in English than in German. Both the success of one model and the failure of the other highlight fundamental differences between 2 major classes of computational models.     

Action-based and vision-based selection of input: Two sources of control

In the first part of this paper we review evidence suggesting that there exists a mechanism that selects input on the basis of its similarity to the required action. This response-based input selection differs from the more established space- and object-based input selection in that it is not constrained by the structure of the input. Our evidence suggests that the two-choice Stroop effect is caused by this response-based selection mechanism. By contrast, it is known that the flanker effect is determined by the space- and object- based selection mechanisms. We explore whether the conflict resolution of the Stroop and flanker tasks is different as well by embedding these two tasks in a PRP (Psychological Refractory Period) paradigm. We show that the Stroop and the PRP effects are additive whereas the flanker and the PRP effects are underadditive, suggesting that the processes in charge of the conflict resolution in the Stroop and the flanker tasks are indeed different. We discuss possible reasons for this difference, and discuss possible ways in which the response-based mechanism can be implemented in information processing models.     

Win-shift and win-stay learning in the short-beaked echidna (<Emphasis Type="Italic">Tachyglossus aculeatus</Emphasis>)

Numerous previous investigators have explained species differences in spatial memory performance in terms of differences in foraging ecology. In three experiments we attempted to extend these findings by examining the extent to which the spatial memory performance of echidnas (or "spiny anteaters") can be understood in terms of the spatio-temporal distribution of their prey (ants and termites). This is a species and a foraging situation that have not been examined in this way before. Echidnas were better able to learn to avoid a previously rewarding location (to "win-shift") than to learn to return to a previously rewarding location (to "win-stay"), at short retention intervals, but were unable to learn either of these strategies at retention intervals of 90 min. The short retention interval results support the ecological hypothesis, but the long retention interval results do not. Electronic Publication     

Linguistic difficulties in language and reading development constrain skilled adult reading

This study investigated whether the quality and specification of phonological representations in early language development would predict later skilled reading. Two perceptual identification experiments were performed with skilled readers. In Experiment 1, spelling difficulties in Grade 1 were used as a proxy measure for poorly specified representations in early language development. In Experiment 2, difficulties in perceiving and representing liquid and nasalized phonemes in final consonant clusters were used for the same purpose. Both experiments showed that words that were more likely to develop underspecified lexical representations in early language development remained more difficult in skilled reading. This finding suggests that early linguistic difficulties in speech perception and structuring of lexical representations may constrain the long-term organization and dynamics of the skilled adult reading system. The present data thus challenge the assumption that skilled reading can be fully understood without taking into account linguistic constraints acting upon the beginning reader.     

The Factor Structure of the Beavers Interactional Scales

Confirmatory factor analysis and regression analyses of the Beavers Interactional Scales did not appear to support the model offered by its developers, namely, several specified family attributes contributing respectively to two global factors of Family Competence and Family Style. Moreover, regression analysis indicated that only three of 12 items predicted raters' assessments of Global Family Health, and one of seven items predicted Global Family Style. Individuals interested in the family dynamic centripetal/centrifugal might best think of that as a unitary entity and rate it accordingly.     

Male and female delinquency trajectories from pre through middle adolescence and their continuation in late adolescence

This study of male and female adolescent delinquency trajectories focuses on the prediction of late adolescence delinquency, based on earlier delinquency and social support. In this 3-wave longitudinal survey, 270 Dutch adolescents (113 males and 157 females) ages 12 to 14, were followed for a period of 6 years. For males, the level of delinquent activity in late adolescence strongly depends on earlier delinquent activities (R2 = .33, p < .0005). In contrast, the level of female delinquency in late adolescence is far less predictable (R2 = .18, p < .001), and could not be predicted from delinquent activities during pre and early adolescence, while support from the mother during late adolescence was associated with reduced delinquency for females. Different models may be needed to explain the development of delinquency for males versus females.     

Plantinga’s Reformed Epistemology: What’s the Question?

Alvin Plantingas Warranted Christian Belief is without questionone of the central texts of the Reformed epistemology movement. Critiques of Plantingas defence have been both multiple and varied. As varied as these responses are, however, it is my contention that many of them amount to the same thing. It is the purpose of this paper to offer an overview of the main lines of attack that have been directed as Plantingas project, and thereafter to show how many, if not most, of these objections can be understood as versions or aspects of the same criticism, what I call the Inadequacy Thesis.     

Bioethics and Christian Theology

The authors of this essay suggest that the field of bioethics and Christian theology have a great deal to offer to each other. The authors first argue that representatives from both fields must first make sure that they fully and correctly represent their respective position. In other words, scientists, ethicists, and theologians alike must make sure that they present their fields and not use their knowledge merely for personal gain at the stake of misguiding people. Once this is established, the authors then proceed to show the intimate relationship between Christianity and medicine that has existed throughout the ages. It is a call for a continuation of such a relationship that the authors suggest between bioethics and theology. Through an integration of bioethics and Christian theology, both scientists/physicians and theologians are able to gain greater insight into the human person—a focus in both fields.