Temporal discrimination learning of operant feeding in goldfish (Carassius auratus)

Operant temporal discrimination learning was investigated in goldfish. In the first experiment, there was a fixed daily change in illumination. Eight subjects were trained to operate a lever that reinforced each press with food. The period during which responses were reinforced was then progressively reduced until it was 1 hr in every 24. The final 1-hr feeding schedule was maintained over 4 weeks. The feeding period commenced at the same time each day throughout. The food dispensers were then made inactive, and a period of extinction ensued for 6 days. The pattern of responding suggested that the fish were able to exhibit temporal discrimination in anticipation of feeding time. This pattern of responding persisted for a limited number of days during the extinction procedure. The second experiment produced evidence that operant temporal discrimination could develop under continuous illumination.     

Exchange delays and impulsive choice in adult humans.

Choice responding by adult humans in a discrete-trial task was examined as a function of conditions that manipulated either the delay to point delivery or the delay between points and their exchange for money. In point-delay conditions, subjects chose between an "impulsive" alternative that provided a small amount of points immediately and a "self-control" alternative that provided a larger amount of points delayed by 15, 30, or 60 s. Points were exchanged for money immediately following the session. Subjects preferred the self-control alternative. In exchange-delay conditions, subjects chose between a small amount of points exchangeable for money immediately following the session and a larger amount of points exchangeable for money after 1 day, 3 weeks, or 6 weeks. A self-control preference observed for all subjects in the 1-day exchange-delay condition reversed to exclusive impulsive preference for 4 of the 6 subjects when choice conditions involved exchange delays of 3 or 6 weeks. These results show that human choice is sensitive to the manipulation of exchange delays and that impulsive preference can be obtained with exchange delays on the order of weeks.     

Social epistemology and reflexivity: Two versions of how to be really useful

This essay argues that the really useful character of reflexivity is that it enables a radical critique of representation and its conventional material and rhetorical practices. It is uniquely able to produce paradox and thus disrupt discourses by undermining authorial privilege. Because Fuller's social epistemology is insensitive to its own reflexive implications, and limits itself to normative questions about knowledge policy, it is too limited — and limiting — to provide a context that can nurture reflexivity.     

Families and family therapy in Germany

The author describes some of the effects of decades of life under a dictatorship for East Germans and the effects on family life and family therapy of changes following the recent reunification of Germany. A case example illustrates some intergenerational family problems associated with the changes. Contrasts are drawn between East and West Germany and family therapy's present stage of development is depicted in both parts of the reunified country. Germany has approximately 10,000 trained family therapists, a minority of whom work in private practice. The largest amount of family and couples therapy is performed in agencies.Portions of this material were first presented in a poster session at the American Association for Marriage and Family Therapy annual conference in Miami Beach, 1992.     

Circular definitions,circular explanations,and infinite regresses

This paper discusses some of the ways in which circular definitions and circular explanations entail or fail to entail infinite regresses. And since not all infinite regresses are vicious, a few criteria of viciousness are examined in order to determine when the entailment of a regress refutes a circular definition or a circular explanation.I would like to thank Professors Robert Tully, Howard Sobel, and Derek Allen for their constructive comments.     

Teaching simple addition to children with mental retardation using a microcomputer

Computer assisted instruction (CAI) was used for improving the efficiency of simple addition (single-digit without carrying) computation in three children with mental retardation. The training program, conducted on a portable personal computer, consisted of demonstrations and repetitive practices on simple addition presented in a vertical format. A number of behavioral instruction techniques such as direct feedback, corrective demonstration, verbal association, and token reinforcement were also included. To evaluate the effects of the CAI package, a multiple-baseline across subjects design with followup was employed. Results showed that performances of children improved with training and were maintained at 1-week, 4-week, and 12-week followups. Generalization of the learned skills was evident when children were assessed on a paper-and-pencil addition test in a vertical format. The skills were also transferable, with initial prompting, to a computerized addition test in a horizontal format. These findings reaffirmed the applicability of CAI and behavioral techniques for teaching math skills to children with mental retardation.     

Cultural competency in genetic counseling

Incorporating a cross-cultural curriculum into genetic counseling training programs demonstrates a professional conviction of genetic counselors that cultural issues are important in genetic counseling. Funded by the Special Projects Fund in 1993 from the National Society of Genetic Counselors and the Kitson Fund from the Department of Social, Organizational, and Counseling Psychology, Teachers College, Columbia University, theHandbook of Cross-Cultural Genetic Counseling was developed to provide genetic counseling programs a curriculum to teach cross-cultural genetic counseling. The theoretical rationale for the development of a cultural curriculum is presented. By expanding cultural knowledge, developing an awareness of oneself and others, and increasing the repertoire of culturally relevant counseling skills within a socio-political context, genetic counselors will be able to better serve all clients seeking genetic counseling.