Divided attention between simultaneous auditory and visual signals

Past studies of simultaneous attention to pairs of visual stimuli have used the “dual-task” paradigm to show that identification of the direction of a change in luminance, whether incremental or decremental, is “capacity-limited,” while simple detection of these changes is governed by “capacity-free” processes. On the basis of that finding, it has been suggested that the contrast between identification and detection reflects different processes in the sensory periphery, namely the responses of magno- and parvocellular receptors. The present study questions that assertion and investigates the contribution of central processing in resource limitation by applying the dual task to a situation in which one stimulus is auditory and one is visual. The results are much the same as before, with identification demonstrating the tradeoff in performance generally attributed to a limited capacity but detection showing no loss compared with single-task controls. This implies that limitations on resources operate at a central level of processing rather than in the auditory and visual peripheries.     

Abstract versus Causal Explanations?

In the recent literature on causal and non-causal scientific explanations, there is an intuitive assumption (which we call the ‘abstractness assumption’) according to which an explanation is non-causal by virtue of being abstract. In this context, to be ‘abstract’ means that the explanans in question leaves out many or almost all causal microphysical details of the target system. After motivating this assumption, we argue that the abstractness assumption, in placing the abstract and the causal character of an explanation in tension, is misguided in ways that are independent of which view of causation or causal explanation one takes to be most accurate. On major accounts of causation, as well as on major accounts of causal explanation, the abstractness of an explanation is not sufficient for it being non-causal. That is, explanations are not non-causal by dint of being abstract.     

Traumatic stress, perceived global stress, and life events: prospectively predicting quality of life in breast cancer patients.

The authors investigated the relationship between stress at initial cancer diagnosis and treatment and subsequent quality of life (QoL). Women (n = 112) randomized to the assessment-only arm of a clinical trial were initially assessed after breast cancer diagnosis and surgery and then reassessed at 4 months (during adjuvant treatment) and 12 months (postadjuvant treatment). There were 3 types of stress measured: number of stressful life events (K. A. Matthews et al., 1997), cancer-related traumatic stress symptoms (M. J. Horowitz, N. Wilner, & W. Alvarez, 1979), and perceived global stress (S. Cohen, T. Kamarck, & R. Mermelstein, 1983). Using hierarchical multiple regressions, the authors found that stress predicted both psychological and physical QoL (J. E. Ware, K. K. Snow, & M. Kosinski, 2000) at the follow-ups (all ps < .03). These findings substantiate the relationship between initial stress and later QoL and underscore the need for timely psychological intervention.     

Diffusion of e-commerce in Denmark: An analysis of institutional intervention

This article analyzes the way a series of recent policy statements have been used to promote and shape the take-up of e-commerce in Denmark. Issuing periodic policy statements, with a combination of direct and indirect modes of intervention, is one of the roads governments are taking to influence the evolutions of ICT. The policy statements present the goals, launch initiatives, and assess achievements. Complementing a co-or self-regulation strategy, the policy statement approach has become particularly important in areas where governments seek to influence the take-up of a technology without appearing to tip the scales. She did her Ph.D. at the Center for Electronic Commerce, at Department of Informatics, Copenhagen Business School. Helle Zinner Henriksen has a degree in Law (University of Copenhagen, 1995). Her research interests include: Adoption and diffusion of Interorganizational Information Systems, e-government, and institutional regulation of electronic commerce and e-government. Kim Viborg Andersen is a researcher in organizational and policy aspects of IT. Andersen’s research encompasses various applications: economic models, EIS/BIS, health data network, EDI, e-commerce, and mobile applications primarily within the public sector domain. He is co-founder of the AIS SIG on e-government, vice-chair of the IFIP WG 8.4 on interdisciplinary e-business and on various editorial boards for journals. He is head of the Center for Research on Information Technology in Policy Settings (CIPS) at the Copenhagen Business School.     

Nanoethics—A Collaboration Across Disciplines

The field of nanoscience and nanotechnology is expanding rapidly, promising great benefits for society in the form of better medicine, more efficient energy production, new types of materials, etc. Naturally, in order for the science and technology to live up to these promises, it is important to continue scientific research and development, but equally important is the ethical dimension. Giving attention to the social, ethical and legal aspects of the field, among others, will help in developing a fully responsible—and thereby capable—science and technology. Nanoethics has emerged as a field concerned with such ethical issues related to nanoscience and nanotechnology. Even though this field is relatively new, a significant amount of literature has already been published. This paper focuses on three of the major issues which are discussed in the literature of nanoethics, and also points to a certain bias in this literature. Each quite different in nature, these issues are: (1) The naming and (2) the timing of and approach to the field, as well as (3) the issue of safety. As will be seen, these issues are almost exclusively discussed by ethicists, (throughout the article, the term’ethicist’ is used in a broad definition covering philosophers, social and political scientists as well as philosophers of science) thus having no direct influence on the work being carried out by scientists. One can argue, therefore, that this bias creates a distortion of the ethical debate, making it insufficient and misleading. Ultimately, this bias is caused by the lack of communication and collaboration between ethicists on the one hand, and nanoscientists on the other. Thus, an argument is made for the different disciplines to begin collaborating, so as to more effectively and responsibly develop the field of nanoscience.     

One night of sleep deprivation affects reaction time, but not interference or facilitation in a Stroop task

The Stroop color-naming task is one of the most widely studied tasks involving the inhibition of a prepotent response, regarded as an executive function. Several studies have examined performance on versions of the Stroop task under conditions of acute sleep deprivation. Though these studies revealed effects on Stroop performance, the results often do not differentiate between general effects of sleep deprivation on performance and effects specifically on interference in the Stroop task. To examine the effect of prolonged wakefulness on performance on the Stroop task, we studied participants in a 40-h "constant routine" protocol during which they remained awake in constant conditions and performed a Stroop color-naming task every two hours. We found that reaction time was slowest when the color and word did not match (incongruent), fastest when the color and word did match (congruent), and intermediate when participants named the color of the non-word stimulus (neutral). Performance on all three trial types degraded significantly as a function of time awake. Extended wakefulness did not significantly change the additional time needed to respond when the color and word did not match (Stroop interference), nor did it change the amount of facilitation when color and word matched. These results indicate that one night of sleep deprivation influences performance on the Stroop task by an overall increase in response time, but does not appear to impact the underlying processes of interference or facilitation. The results suggest that the degree to which an "executive function" is affected by sleep deprivation may depend on the particular executive function studied and the degree to which it is subserved by the prefrontal cortex.