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.     

Unconscious influences revealed. Attention, awareness, and control.

Recent findings of dissociations between direct and indirect tests of memory and perception have renewed enthusiasm for the study of unconscious processing. The authors argue that such findings are heir to the same problems of interpretation as are earlier evidence of unconscious influences--namely, one cannot eliminate the possibility that conscious processes contaminated the measure of unconscious processes. To solve this problem, the authors define unconscious influences in terms of lack of conscious control and then describe a process dissociation procedure that yields separate quantitative estimates of the concurrent contributions of unconscious and consciously controlled processing to task performance. This technique allows one to go beyond demonstrating the existence of unconscious processes to examine factors that determine their magnitude.     

Fluency versus conscious recollection in the word completion performance of amnesic patients

To examine the relative contribution of fluency and recollection to the word completion performance of amnesics, we administered a task in which patients were told specifically not to utilize previously presented words during stem completion (an Exclusion condition). This condition was contrasted with a standard word completion task in which patients were encouraged simply to complete the stem with the first word that came to mind (an Inclusion condition). Since the exclusion condition necessitated controlled respecification of the initial presentation, it was hypothesized that amnesics would be less able than controls to exclude study list items. Consistent with this hypothesis, the results indicated that the amnesics' performance, unlike that of the alcoholic controls, did not significantly differ as a function of task condition. To examine whether amnesics' conscious recollection could be enhanced, Experiment 2 presented the study list five times. The amnesics now were able to exclude a significant number of items from the study list; however, they still did so considerably less frequently than alcoholic controls. For the alcoholic controls, increasing the number of study trials had little additional effect on their exclusion performance, but it significantly enhanced their inclusion performance. Taken together, these findings suggest that for control subjects, word completion performance is likely mediated by a combination of fluency and recollection, while for amnesic patients, performance is almost exclusively based on the fluency with which an item comes to mind.     

Specific word transfer as a measure of processing in the word-superiority paradigm

Explanations of context effects in the Reicher-Wheeler task and the letter-identification task appeal to word-based processing, yet these tasks provide no explicit measure of word processing. An experiment is reported which was designed to investigate the use of transfer in the word-identification task as a measure of word-based processing in letter-identification tasks. It was found that encoding manipulations that determined whether a word-superiority effect was or was not found in a letter-identification task (e.g., Thompson & Massaro, 1973) also determined whether transfer was or was not found in a subsequent word-identification task. The results of the experiment are discussed in terms of the utility of using transfer experiments as converging evidence about the presence and/or absence of processes that cannot be directly measured in other experimental paradigms.