Concept learning at different levels of abstraction by pigeons, monkeys, and people.

Pigeon, monkey, and human subjects were trained on three two-choice picture discrimination problems that varied in level of abstraction. At the most concrete level, subjects were rewarded for choosing pictures of a single species of bird, the common kingfisher, and nonrewarded for choosing pictures of other birds. At an intermediate level of abstraction, subjects were required to discriminate bird pictures as a general category from pictures of nonbird animals. As the most abstract problem, animal pictures in general were S+ items, and nonanimal pictures were S– items. Tests with novel probe pairs of pictures in Experiment 1 indicated that human subjects rapidly mastered all three concepts. Pigeons and monkeys performed well on the concrete kingfisher problem but not on the more abstract birds and animals problems. Although this initial experiment suggested that concept learning in pigeons and monkeys might be limited to concrete categories, further training with more exemplars in Experiment 3 revealed accurate identification of animal pictures in contrast to nonanimal pictures. On the other hand, both pigeons and monkeys showed an inability to discriminate novel bird pictures from pictures of other classes of animals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Open-set speech perception in congenitally deaf children using cochlear implants

A review of the literature examining school-based prevention and treatment intervention programs for smokeless tobacco users is provided. Although few school-based prevention studies have been conducted, the results are promising. Many of the treatment studies that have been conducted, thus far, are limited due to the sample size and the lack of a control group. However, of the studies that have not had these limitations, the results are also promising. In general, studies show that intervention in the dental office can be effective and that group behavioral treatment may also improve cessation rates over minimal contact. On the other hand, pharmacological treatment, which has primarily focused on 2 mg nicotine gum, has not been found to be an effective treatment. Dentists are in an ideal position to advise and assist smokeless tobacco users to quit. The majority of smokeless tobacco users want advice and help from their dentists, and a significant number indicate that discussion of the negative oral effects from the use of smokeless tobacco has an impact on their desire to quit.