Preventing Substance Abuse Among American-Indian Adolescents: A Bicultural Competence Skills Approach

Tobacco, alcohol, and drug use are problems for American-Indian people. We reviewed these problems and the explanations for them and described a bicultural competence skills approach for preventing substance abuse with American-Indian adolescents. Data from a study of that approach suggest its efficacy with American-Indian youth. At posttest and a 6-month follow-up, American-Indian subjects who received preventive intervention based on bicultural competence skills concepts improved more than did American-Indian subjects in a no-intervention control condition on measures of substance-use knowledge, attitudes, and interactive skills, and on self-reported rates of tobacco, alcohol, and drug use. Our findings have implications for future substance-abuse prevention research with American-Indian people.     

The height of a stereokinetic cone: A quantitative determination of a 3-D effect from 2-D moving patterns without a “rigidity assumption”

Summary When a circular disc with an eccentric dot painted on it is set in slow circular motion, a three-dimensional solid object appears to the observer: the stereokinetic cone. The cone shows a well-defined height and tilt. All current theories of how the visual system can extract 3-D percepts from 2-D moving patterns, are based on a rigidity assumption hypothesis. But this assumption cannot explain why the stereokinetic cone appears to have a well-defined height. An alternative hypothesis is proposed here, which avoids the rigidity assumption and is based on a minimization process of the relative velocity differences between all the points of the rotating pattern. The hypothesis allows a quantitative prediction of the stereokinetic cone height both when the rotating disc is circular and when it is elliptical. The predictions are in good agreement with previously reported experimental results and with our own observations.     

Conceptualizations of valence and instrumentality: A fourfold model

Within the framework of valence-instrumentality (VI) theory, a fourfold model is developed to predict the contribution which is made by one outcome of an alternative to the valence of that alternative. The proposed model uses four subjective conditional probabilities which are based on the presence and absence of an alternative, and on the occurrence and nonoccurrence of an outcome. Valence is defined as the difference between the attractiveness values of the occurrence of an alternative (or an outcome) and the nonoccurrence of an alternative (or an outcome). Also, differences between subjective probabilities replace instrumentalities. Alternative valence-instrumentality formulations are analyzed in relation to the proposed fourfold model. The proposed model can be understood as a consistent application of Vroom's model (1964, Work and motivation, New York: Wiley), while other models are judged to be relatively deficient. The fourfold model, in combination with a matrix formulation of expectancy concepts, addresses a number of criticisms of VI theory and makes possible a test of the theory within the limits of its own assumptions.     

Influencing prior knowledge through a short reading impacts curiosity and learning

Curiosity predicts memory performance and it is influenced by prior knowledge. Reading a well-organized text can increase curiosity in a classroom setting, however it is not clear if reading a short text written in an encyclopedic style can increase curiosity and learning without explicit educational goals. We presented participants with a short text and examined if questions related to this reading could elicit higher curiosity ratings and better recall in a thematized version of the trivia task. In the first experiment, participants subjectively judged their prior knowledge of trivia questions. The curiosity of the participants was not influenced by the reading, but the memory effect of curiosity was amplified for the questions related to it. In the second experiment, we objectively verified whether the participants knew the answers. The curiosity ratings were higher for the questions related to the reading, but only the curiosity ratings influenced recall performance. These results show that prior knowledge induced by reading can have an effect on curiosity and learning, but it depends on how this knowledge is assessed by the learner.