A critical comparison of two random-walk models for two-choice reaction time

Two random-walk models for two-choice reaction time, being the sequential probability ratio test model initially suggested by Stone and the relative judgment theory recently proposed by Link, are here compared. The comparison shows the precise mathematical relation between the models, the predictions they have in common, and two points at which they differ. Three experiments concerned with the effect of stimulus probability on two-choice reaction time are examined with respect to three predictions from the models. In this three-way comparison the two models are more like each other than either is to the data; a greater variety of phenomena is revealed than either model can at present accommodate.     

Autocorrelation of choice-reaction times.

A choice-reaction (CR) task requires that the subject estimate, raking the warning signal or his response on the preceding trial as a reference point, the time when the reaction stimulus is due, so that he can begin deciding on his response at an appropriate time. This paper presents a model for the reproduction of temporal intervals, with particular emphasis on the sequential statistics of a series of such reproductions. When this model is concatenated with the sequential probability ratio test model for 2CRT, it provides a quantitative account of the pattern of autocorrelation found in a series of RTs. There is no corresponding autocorrelation in the incidence of errors, however, because after an error the subject systematically adjusts the epoch at which he begins sampling as a precaution against a further error. These post-error adjustments can readily be incorporated into the model. The ideas presented enable several different CR phenomena to be related, and they have implications for the relation between speed and accuracy, for the form of empirical distributions of RTs, and for the effects of temporal uncertainty.     

RALPH WENDELL BURHOE: HIS LIFE AND HIS THOUGHT

Abstract. This is the first of four installments by the author, presenting an intellectual biography of Ralph Wendell Burhoe. This first segment follows Burhoe from his college years at Harvard through the founding of the Institute on Religion in an Age of Science in 1954. In this period, after his college and seminary study, Burhoe worked at Harvard's Blue Hill Meteorological Observatory and as executive officer of the American Academy of Arts and Sciences. Throughout his early life he had been concerned with how religion could maintain its credibility as a bearer of truth vis-à-vis the sciences, which were displacing religion not only among leading intellectuals, but also in other segments of society. The founding of IRAS provided an important instrument for dealing with this concern.     

Contradictions in the American dream: High educational aspirations and perceptions of deteriorating institutional support

This study examines contradictions in the “American Dream” during the Great Recession: young adults maintained high educational aspirations, yet perceived little opportunity for their educational achievements to help them fulfil their dreams of financial prosperity and work stability. Based on in‐depth interviews with 85 young college students and recent graduates, this study found that college enrolment was propelled by the recession, as a college degree, and often a graduate or professional degree, was perceived as an increasingly necessary credential. Despite these high educational aspirations, students and recent graduates were fearful about their capacity to find future work and they expressed concerns about the collapse of employment opportunity. Many were also wary of educational institutions, which they viewed as unable to prepare them for a shrinking job market. These perceptions reveal a contradiction in the “American Dream:” although young adults have high aspirations and achievements, they have lost confidence in the educational and work institutions upon which they must depend.     

The Great Apes and the Severely Disabled: Moral Status and Thick Evaluative Concepts

The literature of bioethics suffers from two serious problems. (1) Most authors are unable to take seriously both the rights of the great apes and of severely disabled human infants. Rationalism—moral status rests on rational capacities—wrongly assigns a higher moral status to the great apes than to all severely disabled human infants with less rational capacities than the great apes. Anthropocentrism—moral status depends on membership in the human species—falsely grants all humans a higher moral status than the great apes. Animalism—moral status is dependent on the ability to suffer—mistakenly equates the moral status of humans and most animals. (2) The concept person is widely used for justificatory purposes, but it seems that it cannot play such a role. It seems that it is either redundant or unable to play any justificatory role. I argue that we can solve the second problem by understanding person as a thick evaluative concept. This then enables us to justify assigning a higher moral status to the great apes than to simple animals: the great apes are persons. To solve the first problem, I argue that certain severely disabled infants have a higher moral status than the great apes because they are dependent upon human relationships for their well-being. Only very limited abilities are required for such relationships, and the question who is capable of them must be based on thick evaluative concepts. Thus, it turns out that to make progress in bioethics we must assign thick evaluative concepts a central role.

From great commission to inclusive education: a tangible illustration of missionaries’ legacy

This article analysed missionaries’ roles in the development of general and special education by examining the relationship between the Great Commission and education and the biblical perspective on disabilities as the foundational links between their work and inclusive education. While missionaries have not been directly involved in the practices of inclusive education today, their work in initiating and formalising special education services has facilitated a more welcoming attitude toward individuals with disabilities, and propelled governments around the globe to make special and inclusive education a public responsibility when socio-political environments demand it. To provide a concrete illustration, this article used Hong Kong as an example by examining missionaries’ key involvements and impact in its development of public education from the early colonial era to today’s inclusive education. The missionaries’ legacy in Hong Kong’s inclusive education development lay in their nurturing of Christian educators as supported by a high number of public Christian schools and Christian educators advocated for inclusive education, and in their efforts to formalise special education during the early colonial era (175).     

Preference for spatial cues in a non-storing songbird species

Male mammals typically outperform their conspecific females on spatial tasks. A sex difference in cues used to solve the task could underlie this performance difference as spatial ability is reliant on appropriate cue use. Although comparative studies of memory in food-storing and non-storing birds have examined species differences in cue preference, few studies have investigated differences in cue use within a species. In this study, we used a one-trial associative food-finding task to test for sex differences in cue use in the great tit, Parus major. Birds were trained to locate a food reward hidden in a well covered by a coloured cloth. To determine whether the colour of the cloth or the location of the well was learned during training, the birds were presented with three wells in the test phase: one in the original location, but covered by a cloth of a novel colour, a second in a new location covered with the original cloth and a third in a new location covered by a differently coloured cloth. Both sexes preferentially visited the well in the training location rather than either alternative. As great tits prefer colour cues over spatial cues in one-trial associative conditioning tasks, cue preference appears to be related to the task type rather than being species dependent.     

EVOLVING APPROACHES TO CONSERVATION: INTEGRAL ECOLOGY AND CANADA'S GREAT BEAR RAINFOREST

This case study applies Integral Ecology to analyze the broad range of strategies environmentalists have undertaken to create protected areas and change forest practices in the Great Bear Rainforest, British Columbia, Canada. Rainforest conservation efforts in the region promoted holistic, trans-disciplinary solutions and fostered agreement among diverse stakeholders, modeling an Integral Ecology approach. Environmentalists worked locally and globally, engaging with economic, cultural, political, and scientific systems to create change. The campaign involved transformations at personal and cultural levels that have enabled negotiated solutions involving over twenty million acres of rainforest on British Columbia's coast.