Postdiscrimination generalization as a function of interresponse time

Following 20 sessions of variable-interval 20-sec reinforcement in the presence of a single 45-deg line-tilt stimulus, three pigeons were trained to discriminate between line tilts of 45 deg correlated with variable-interval 20-sec reinforcement and line tilts of 15 deg correlated with extinction. A generalization test along the line-tilt dimension was administered following a criterion discrimination performance. Gradients derived in terms of relative frequency of response as a function of line tilt indicated strong external stimulus control and exhibited clear peak shift. From the interresponse time (IRT) distributions generated for responding to each test stimulus, probability of response conditional upon IRT (IRTs/Op) was derived as a joint function of line tilt and IRT. The IRTs/Op functions for responses following IRTs in 0.2-sec-wide classes from 0.2 to 1.0 sec and for responses following IRTs in the interval of 1.0 to 2.0 sec were similar to the relative generalization gradients and also exhibited peak shift. Few IRTs were greater than 2.0 sec. External stimulus control was established over responses terminating IRTs both longer and shorter than 1.0 sec.     

¿Qué clases y profesores tendremos para la enseñanza de las matemáticas? Posibilidades y alternativas

La pregunta que se plantea el titular de este artículo no es sino una de entre las muchas que se plantean a lo largo del texto acerca de los protagonistas, los contextos y los recursos que pueden ponerse en marcha en un futuro ya presente, al menos en las sociedades avanzadas. Se pasa revista desde el modelo de aula que se avecina, a las nuevas tecnologías—el ordenador y su software, pero también los audiovisuales o el propio texto escrito—, hasta el modelo de profesor y de relación educativa que implican esos nuevos contextos.     

Laterality,Implicit Memory and Attention Disorder

Children who presented behaviours characteristic of attention disorder/hyper‐activity deficit (ADHD), but who were functioning adequately in ordinary schools, were assessed on a range of tests including some focused particularly on cognitive abilities, including verbal and figural aspects of problem solving and creativity. An attempt was made to replicate an earlier study, incorporating refinements to the manner in which pupils were selected from the schools. In spite of cultural differences, the pattern of results substantially duplicated the earlier findings, suggesting a stable pattern of characteristics associated with ADHD and high intelligence. Specifically these children were found to have more mixed laterality and allergies, to gather and use more diverse, nonverbal and poorly focused information, and to show higher figural creativity than did high‐IQ children without attention problems. It was concluded that uncommon information was made use of by ADHD children when exhibiting novelty in nonverbal thinking. This supports Geschwind's prediction that high talent would be found in some types of learning‐disordered individuals.     

Probing Children's Prejudice‐‐a consideration of the ethical and methodological issues raised by research and curriculum development

Since the mid‐1980s many schools in predominantly white areas have taken active steps to counter racism and ethnocentrism and raise awareness of Britain's ethnic diversity through curriculum development. This paper is primarily concerned with the ethical issues raised by research into such initiatives at primary school level. We begin by alluding very briefly to the shortcomings of extant research into children's prejudice, noting that some studies can be criticised for the unwitting reinforcement of stereotypes. We move on to examine the ethical and methodological considerations which have underpinned our own work in this area, focusing on a recent investigation into children's understanding of Jewish culture and identity. The techniques employed to probe the children's beliefs and attitudes and challenge their taken‐for‐granted assumptions are described at length, together with the ethical dilemmas addressed during the course of the research. In the second part of the paper, we focus on issues raised by our own curriculum development work in anti‐racist and multicultural education in ‘all white’ schools. We draw extensively on a recent case‐study of 10 and 11 year‐olds’ responses to a teaching programme which aimed to counter stereotypical images both of developing countries and Islam.