Beyond Stewardship? Dietrich Bonhoeffer on Nature

This article questions whether the model of stewardship is helpful in considering Christian responsibility towards non‐human nature and proposes a different way of treating the issue of care of the environment. In an extended engagement with the theology of Dietrich Bonhoeffer, the article argues that human relations to non‐human nature are best understood by seeing humanity as historical, political and natural. In theological formulation, humanity must be understood asimago dei, imago civitatis andimago mundi. Therefore the place of humanity cannot properly be understood without reference to both God and nature. Humanity, nature and God thereby constitute a ‘common realm’. A new test of Christian responsibility towards non‐human nature is introduced: of primary interest is how historical, political and natural humanity acts in ways which either reveal or obscure the ‘common realm of God, nature and humanity’. At this point, theological self‐understanding moves beyond the model of stewardship.     

BasicBayes: A tutor system for simple Bayesian inference

To date, attempts to teach Bayesian inference to nonexperts have not met with much success. BasicBayes, the computerized tutor presented here, is an attempt to change this state of affairs. BasicBayes is based on a novel theoretical framework about Bayesian reasoning recently introduced by Gigerenzer and Hoffrage (1995). This framework focuses on the connection between “cognitive algorithms” and “information formats.” BasicBayes teaches people how to translate Bayesian text problems into frequency formats, which have been shown to entail computationally simpler cognitive algorithms than those entailed by probability formats. The components and mode of functioning of BasicBayes are described in detail. Empirical evidence demonstrates the effectiveness of BasicBayes in teaching people simple Bayesian inference. Because of its flexible system architecture, BasicBayes can also be used as a research tool.     

THE CRISIS OF VIRTUE: ARMING FOR THE CULTURAL WARS AND PELLEGRINO AT THE LIMES

Theoretical Medicine and Bioethics -     

Holiness, virtue, and social justice: contrasting understandings of the moral life.

Being a Christian involves metaphysical, epistemological, and social commitments that set Christians at variance with the dominant secular culture. Because Christianity is not syncretical, but proclaims the unique truth of its revelations, Christians will inevitably be placed in some degree of conflict with secular health care institutions. Because being Christian involves a life of holiness, not merely living justly or morally, Christians will also be in conflict with the ethos of many contemporary Christian health care institutions which have abandoned a commitment to Christian spirituality. In this regard, managed care raises the special question of how Christian institutions can act morally under financial constraints and maintain their character while under the control of secular managers. This question itself raises the further question as to why health care institutions need even pose this query when there are Christian physicians and nurses who could work for less, or Christian men and women who could become sisters and brothers and work for nothing. Contemporary challenges to Christians to maintain their integrity in a post-Christian world have much of their force because Christians have failed to maintain traditional Christian sprituality. In the face of that failure, Christian physicans and nurses will find themselves in greater conflict with health care institutions, because few will any longer understand the requirements of traditional Christianity. In its place, they will have put a generic spirituality, a value-neutral understanding of the role of the health professional, and an anonymous commitment to social justice.     

The organization of multidimensional selection on the basis of color and shape: An event-related brain potential study

In this paper, we examine whether color and shape, tied to a single object in space, (1) are identified and selected in series or in parallel, (2) are identified and selected in a dependent, self-terminating manner or in an independent and exhaustive manner, and (3) are conjoined by a feature integration process before or only after an initial stage of separate attribute analyses has finished. We measured response time and the selection negativity (SN) derived from event-related brain potentials when participants responded to a unique conjunction of color and shape in a go/no-go target detection task. The discriminability of the color and the shape of the conjunction was manipulated in three conditions. When color and shape were easy to discriminate, the SNs to color and shape started at the same time. When one attribute was less discriminable, the SN to that attribute started later, but not the SN to the complementary attribute. This suggests that color and shape are identified and selected in parallel. In all three discriminability conditions, the SNs to color and shape were initially independent but later interacted. This suggests that color and shape are initially selected independently and exhaustively, after which their conjunction is analyzed. The SN to local shape features started later than that to the conjunction of color and global shape features, which suggests that feature integration can start before the analyses of the separate attributes have finished.     

A multidimensional scaling analysis of vowel discrimination in humans and monkeys

Multidimensional scaling (MDS) was used to compare perceptual maps for 10 synthetic English vowels in humans and Old World monkeys (Macaca fuscata andCercopithecus albogularis). Subjects discriminated among the vowels using a repeating background procedure, and reaction times were submitted to an MDS analysis to derive measures of perceived similarity. The dimensions that emerged related to the frequencies of the first(F1), second(F2), and third(F3) formants. Human data indicated a good match to previous MDS studies using rating procedures or confusion matrices: The dominant dimension mapped onto vowelF2, the phonetically most important formant, and the second and third dimensions mapped ontoF1 andF3, respectively.For monkeys, equal weightings occurred forF1 andF2, andF3 was not clearly represented. Monkey sensitivity to the formants appeared to relate to formant amplitudes. If monkeys are giving an accurate representation of the psychoacoustic relations among the formants, then our human results suggest that species-specific mechanisms, reflecting the salience of the phonetic feature of advancement, may contribute to vowel coding in humans.     

Heading and path information from retinal flow in naturalistic environments

In four experiments, we explored the heading and path information available to observers as we simulated their locomotion through a cluttered environment while they fixated an object off to the side. Previously, we presented a theory about the information available and used in such situations. For such a theory to be valid, one must be sure of eye position, but we had been unable to monitor gaze systematically; in Experiment 1, we monitored eye position and found performance best when observers fixated the designated object at the center of the display. In Experiment 2, when we masked portions of the display, we found that performance generally matched the amount of display visible when scaled to retinal sensitivity. In Experiments 3 and 4, we then explored the metric of information about heading (nominal vs. absolute) available and found good nominal information but increasingly poor and biased absolute information as observers looked farther from the aimpoint. Part of the cause for this appears to be that some observers perceive that they have traversed a curved path even when taking a linear one. In all cases, we compared our results with those in the literature.     

The effect of spatial frequency on global precedence and hemispheric differences

There are many conditions in which identification proceeds faster for the global form of a hierarchical pattern than for its local parts. Since the global form usually contains more lower spatial frequencies than do the local forms, it has frequently been suggested that the higher transmission rate of low spatial frequencies is responsible for the global advantage. There are also functional hemispheric differences. While the right hemisphere is better at processing global information, the left hemisphere has an advantage with respect to local information. In accordance with the spatial-frequency hypothesis, it has been speculated that this difference is due to a differential capacity of the hemispheres for processing low and high spatial frequencies. To test whether low spatial frequencies were responsible for the global advantage and/or for the observed hemispheric differences, two experiments were carried out with unfiltered and highpass-filtered compound-letter stimuli presented at the left, right, or center visual field. The first experiment, in which the target level was randomized in each trial block, revealed that low spatial frequencies were not necessary for either global advantage or for hemispheric differences. Highpass filtering merely increased the response times. In the second experiment, the target level was held constant in each block. This generally increased the speed of responding and produced interactions between filtering and global-local processing. It was concluded that both sensory and attentional or control mechanisms were responsible for global precedence and that the hemispheres differed with respect to the latter.