Different responses in two strains of chickens (<Emphasis Type="Italic">Gallus gallus</Emphasis>) in a magnetic orientation test

Previous studies demonstrated that layer strain domestic chicks bred for egg production can orient using directional cues from the magnetic field; here we report that chicks from a broiler strain bred for meat production do not use magnetic cues for orientation. We imprinted both strains of chicken on a red ball and subsequently trained them in a featureless testing arena. Between rewarded trials in the geomagnetic field, we inserted unrewarded tests under the following conditions: (1) in the geomagnetic field, (2) in a magnetic field with North shifted by 90 degrees and (3) in a magnetic field with the inclination inverted. The layer chicks made a correct axial response in 75-80% of the tests, shifting their choices following a rotation of magnetic North. Chicks of the broiler strain, in contrast, performed at chance level with between 47 and 60% of choices on the correct axis. This difference between the strains does not appear to be due to substantial strain differences in motivation to perform the task. It therefore appears possible that the selection of the broiler strain has led to the elimination of the specific ability to respond to magnetic cues in the test situation.     

Platitudes against Paradox

We present a strategy to dissolve semantic paradoxes which proceeds from an explanation of why paradoxical sentences or their definitions are semantically defective. This explanation is compatible with the acceptability of impredicative definitions, self-referential sentences and semantically closed languages and leaves the status of the so-called truth-teller sentence unaffected. It is based on platitudes which encode innocuous constraints on successful definition and successful expression of propositional content. We show that the construction of liar paradoxes and of certain versions of Curry’s paradox rests on presuppositions that violate these innocuous constraints. Other versions of Curry’s paradox are shown not to be paradoxical at all once their presuppositions are made explicit. Part of what we say rehearses a proposal originally made by Laurence Goldstein in 1985. Like Goldstein we dispose of certain paradoxes by rejecting some of the premises from which they must be taken to proceed. However, we disagree with his more recent view that the premises to be rejected are neither true nor false.     

Exploiting redundancy for flexible behavior: unsupervised learning in a modular sensorimotor control architecture

Autonomously developing organisms face several challenges when learning reaching movements. First, motor control is learned unsupervised or self-supervised. Second, knowledge of sensorimotor contingencies is acquired in contexts in which action consequences unfold in time. Third, motor redundancies must be resolved. To solve all 3 of these problems, the authors propose a sensorimotor, unsupervised, redundancy-resolving control architecture (SURE_REACH), based on the ideomotor principle. Given a 3-degrees-of-freedom arm in a 2-dimensional environment, SURE_REACH encodes 2 spatial arm representations with neural population codes: a hand end-point coordinate space and an angular arm posture space. A posture memory solves the inverse kinematics problem by associating hand end-point neurons with neurons in posture space. An inverse sensorimotor model associates posture neurons with each other action-dependently. Together, population encoding, redundant posture memory, and the inverse sensorimotor model enable SURE_REACH to learn and represent sensorimotor grounded distance measures and to use dynamic programming to reach goals efficiently. The architecture not only solves the redundancy problem but also increases goal reaching flexibility, accounting for additional task constraints or realizing obstacle avoidance. While the spatial population codes resemble neurophysiological structures, the simulations confirm the flexibility and plausibility of the model by mimicking previously published data in arm-reaching tasks.     

Psychotherapeutenausbildung aus Sicht der Absolventen

Background

A survey was performed to assess the current situation in education and to identify critical issues 10 years after the inception of the psychotherapy act in Germany.

Methods

In August 2008 all non-medical psychotherapists who had graduated since 2002 according the psychotherapy act were invited to take part in the survey and a total of 863 persons participated. The answers from 666 could be evaluated corresponding to a participation rate of 20%.

Results

A total of 57.6% of the graduates had completed a full-time training and approximately 50% of the graduates had completed the training within the allotted time. In the majority of cases evaluation occurred only for the theoretical courses. During the practical work (PT I) 36.8% of the graduates did not receive any salary or remuneration, 82% had their own field of activity and of these 38% treated patients without the presence of qualified tutor.

Conclusions

The training often lasts longer than intended, the financial situation in the PT I is exceptionally critical and in clear contrast to the field of activity in this section of training. Further detailed results will be presented and discussed.     

Preserved Implicit Knowledge of a Forgotten Childhood Language

ABSTRACT— Previous research suggests that a language learned during early childhood is completely forgotten when contact to that language is severed. In contrast with these findings, we report leftover traces of early language exposure in individuals in their adult years, despite a complete absence of explicit memory for the language. Specifically, native English individuals under age 40 selectively relearned subtle Hindi or Zulu sound contrasts that they once knew. However, individuals over 40 failed to show any relearning, and young control participants with no previous exposure to Hindi or Zulu showed no learning. This research highlights the lasting impact of early language experience in shaping speech perception, and the value of exposing children to foreign languages even if such exposure does not continue into adulthood.     

Large-Scale Assessment of Change in Student Achievement: Dutch Primary School Students’ Results on Written Division in 1997 and 2004 as an Example

This article discusses large-scale assessment of change in student achievement and takes the study by Hickendorff, Heiser, Van Putten, and Verhelst (2009) as an example. This study compared the achievement of students in the Netherlands in 1997 and 2004 on written division problems. Based on this comparison, they claim that there is a performance decline in this subdomain of mathematics, and that there is a move from applying the digit-based long division algorithm to a less accurate way of working without writing down anything. In our discussion of this study, we address methodological challenges that come in when investigating long-term trends in student achievements, such as the need for adequate operationalizations, the influence of the time of measurement and the necessity of the comparability of assessments, the effect of the assessment format, and the importance of inclusion relevant covariates in item response models. All these issues matter when assessing change in student achievement.     

Liberalism, entitlement, and verdict exclusion

In a series of recent papers, Crispin Wright has developed and defended an epistemic account of borderline cases which he calls ‘Liberalism’. If Verdict Exclusion is the claim that no polar verdict on borderline cases is knowledgeable, then Liberalism implies the view that Verdict Exclusion is itself nothing we are in a position to know. It is a matter of ongoing discussion what more Liberalism implies. In any case, Wright argues that Liberalism affords the means to account for the intuition that polar verdicts on borderline cases are equally permissible. Here I argue that Liberalism fails to deliver and that an account of borderline cases based on Verdict Exclusion fares much better when it comes to showing that our ordinary practice of reaching verdicts on borderline cases is fully legitimate: all it needs is a reassessment of the nature of the claims such verdicts express.     

Cutting the Gordian Knot of Demarcation

A definition of pseudoscience is proposed, according to which a statement is pseudoscientific if and only if it (1) pertains to an issue within the domains of science, (2) is not epistemically warranted, and (3) is part of a doctrine whose major proponents try to create the impression that it is epistemically warranted. This approach has the advantage of separating the definition of pseudoscience from the justification of the claim that science represents the most epistemically warranted statements. The definition is used to explain why proponents of widely divergent criteria for the demarcation between science and pseudoscience tend to be in almost complete agreement on the particular demarcations that should presumably be based on these general criteria.