Conditioned avoidance responses survive contingency degradation in the garden slug,Lehmannia valentiana

Joint presentations of a conditioned stimulus (CS) and an unconditioned stimulus (US) strengthen the contingency between them, whereas presentations of one stimulus without the other degrade this contingency. For example, the CS can be presented without the US either before conditioning (CS–no US and then CS–US; latent inhibition) or after conditioning (CS–US and then CS–no US; extinction). In vertebrate subjects and several invertebrate species, a time lapse usually results in a return of the conditioned response, or spontaneous recovery. However, in land mollusks, spontaneous recovery from extinction has only recently been reported, and response recovery after latent inhibition has not been reported. In two experiments, using conditioned aversion to a food odor as a measure of learning and memory retention, we observed contingency degradation via latent inhibition (Experiment 1) and extinction (Experiment 2) in the common garden slug, Lehmannia valentiana. In both situations, the contingency degradation procedure successfully attenuated conditioned responding, and delaying testing by several days resulted in recovery of the conditioned response. This suggests that the CS–US association survived the degradation manipulation and was retained over an interval of several days.     

Expanding Opportunity for the American People

Hi, everybody. In my State of the Union Address, I talked about the idea of opportunity for all.
Opportunity is the idea at the heart of this country--that no matter who you are or how you started out, with hard work and responsibility, you can get ahead.     

Effects of Headings on Text Summarization

A summarization task was used to study whether headings influence readers' representations of the topic structure of a text. College students (Experiments 1-3) and sixth- and eighth-graders (Experiment 3) summarized a multiple topic text that (a) included headings introducing every new subtopic, (b) included headings introducing half of the new subtopics, or (c) included no headings. In all experiments, topics were more likely to be included in a summary if they were signaled than if they were not signaled. This effect was magnified when the text was only half signaled: Signaled topics were more likely to appear in a summary if only half the text topics were signaled than if all of the topics were signaled; however, unsignaled topics were less likely to appear in a summary if half of the text topics were signaled than if none of the text topics were signaled. The findings demonstrate that readers rely heavily on headings in a task that emphasizes attention to a text's topic structure. It is suggested that previously observed signaling effects on text recall are mediated by effects on how readers represent a text's topic structure. Copyright 2001 Academic Press.     

Teaching: getting it right

This autobiographical article explores the way one North American high school teacher's intuitive teaching principles developed over time. The author uses tennis as a metaphor to try to describe her feelings about the teaching process.     

Distinction through visual art

Visual art is one of the fields where, according to Bourdieu, culture is used to reproduce the class structure. Like other items in the cultural repertoire, paintings, as major examples of visual art, imply social divisions in how they are engaged with by artists, critics and audiences. Within the Bourdieusian framework, cultural engagements with paintings are interpreted as indicators of social position, since appreciation depends on a trained capacity in the family and the educational system, which is often inaccessible to less powerful sections of the population. This would imply that the sorts of paintings favoured by working-class people differ from those preferred by the middle or upper classes. More recent studies have contested the view that a gulf exists between the art tastes of different classes in ways that reproduce the class structure. The argument of the omnivore thesis that distinctions between more popular and legitimate tastes have become blurred has predominantly been based on empirical references in the field of music. This article explores this thesis on the basis of data about visual arts in the Cultural Capital and Social Exclusion project. While some differences continue to be connected to social divisions of income, education and occupational groups, important similarities are found across the board, and certain significant differences appear to relate to factors other than social class, such as ethnicity, age and gender. It is also significant that some people appear disconnected from and disinterested in paintings.