Separation of conjoined twins and the principle of double effect.

This article examines the relationship between the principle of double effect and justification for separation surgeries for conjoined twins. First, the principle of double effect is examined in light of its historical context. It is argued that it can only operate under an absolutist view of good and evil that is compatible with the Bible. Given this foundation for application, scenarios for separating conjoined twins are considered against the criteria for the principle of double effect. It is concluded that the principle of double effect cannot be applied to cases wherein one of the twins must be killed. However, it is noted that this does not leave decision makers without options.     

Common region: a new principle of perceptual grouping.

A new principle of grouping is proposed that is based on elements being located within a common region of space. Demonstrations analogous to Wertheimer's original displays show that this factor strongly influences perceived grouping and is capable of overcoming the effects of other powerful grouping factors such as proximity and similarity. Grouping by common region is further shown to depend on perceived depth relations, indicating that it is influenced by processes that occur after at least some depth perception has been achieved. Further demonstrations suggest that it is dominated by the smallest background area and that it can follow a hierarchical embedding scheme. It is argued that common region cannot be reduced to the effects of proximity, closure, or any other previously known factor and therefore constitutes a genuinely new principle of grouping.     

Partial monotonicity and a new version of the Ramsey test

We introduce two new belief revision axioms: partial monotonicity and consequence correctness. We show that partial monotonicity is consistent with but independent of the full set of axioms for a Gärdenfors belief revision sytem. In contrast to the Gärdenfors inconsistency results for certain monotonicity principles, we use partial monotonicity to inform a consistent formalization of the Ramsey test within a belief revision system extended by a conditional operator. We take this to be a technical dissolution of the well-known Gärdenfors dilemma.In addition, we present the consequential correctness axiom as a new measure of minimal revision in terms of the deductive core of a proposition whose support we wish to excise. We survey several syntactic and semantic belief revision systems and evaluate them according to both the Gärdenfors axioms and our new axioms. Furthermore, our algebraic characterization of semantic revision systems provides a useful technical device for analysis and comparison, which we illustrate with several new proofs.Finally, we have a new inconsistency result, which is dual to the Gärdenfors inconsistency results. Any elementary belief revision system that is consequentially correct must violate the Gärdenfors axiom of strong boundedness (K^*8), which we characterize as yet another monotonicity condition.This work was supported by the McDonnell Douglas Independent Research and Development program.     

Business is not just war. Transferring the principle of double effect from war to business

Abstract

In this article the validity of transferring the Principle of Double Effect from the just war tradition to the domain of business is critically reviewed. If a case can be build for sufficient analogies between war and business, the principle of double effect can legitimately be transferred from war to business. If, on the other hand it can be shown that there are aspects in which business differ substantially from just war, then the transfer to business of a principle developed within the context of war becomes more problematic. After exploring the nature of arguments of analogy and fallacious arguments of weak analogy some important disanalogies between war and business are highlighted. Given these disanalogies it is then contended that the just war background of the Principle of Double Effect had some bearing on both the content and manner of application of the Principle of Double Effect. Finally it is argued that these disanalogies require some revisions to the Principle of Double Effect with regard to both its content and its manner of application before it can be applied meaningfully to foreseeable negative side-effects of business.     

The Mackworth Clock Test: a computerized version

The Mackworth Clock Test (MCT; N. H. Mackworth, 1948) was developed to evaluate vigilance in British Air Force radar technicians during World War II. Homemade versions of the MCT have since varied with respect to both the characteristics of the device and the procedures of its administration. This article is a report on a computerized version of the MCT developed by the authors to closely emulate Mackworth's test. MCT data were collected from 25 undergraduate students; their performance was found to be equivalent to Mackworth's participants' data. This is the first MCT version that has been validated against the original.     

The Spanish version of the Clinical Analysis Questionnaire: a precautionary note

The Spanish version of the Clinical Analysis Questionnaire (CAQ) was examined and found to have numerous grammatical and syntactical errors that seriously limit its usefulness for the psychological evaluation of Spanish-speaking clients. At least 36% of the items were found to be poorly translated from the original English version.     

The puzzle of the unmarked clock and the new rational reflection principle

The “puzzle of the unmarked clock” derives from a conflict between the following: (1) a plausible principle of epistemic modesty, and (2) “Rational Reflection”, a principle saying how one’s beliefs about what it is rational to believe constrain the rest of one’s beliefs. An independently motivated improvement to Rational Reflection preserves its spirit while resolving the conflict.     

The effect of study time distribution on learning and retention: a Goldilocks principle for presentation rate

In 2 experiments, we investigated the effect of presentation rate on both immediate (5 min) and delayed (2 days) cued recall of paired associates. Word pairs were presented for a total of 16 s per pair, with presentation duration of individual presentations varying from 1 to 16 s. In Experiment 1, participants studied word pairs with presentation rates of 16 × 1 s, 8 × 2 s, 4 × 4 s, 2 × 8 s, or 1 × 16 s. A nonmonotonic relationship was found between presentation rate and cued recall performance. Both short (e.g., 1 s) and long (e.g., 16 s) presentation durations resulted in poor immediate and delayed recall, compared with intermediate presentation durations. In Experiment 2, we replicated these general findings. Moreover, we showed that the 4 s condition resulted in less proportional forgetting than the 1 s and the 16 s conditions.     

The effect of sample duration and cue on a double temporal discrimination

To test the assumptions of two models of timing, Scalar Expectancy Theory (SET) and Learning to Time (LeT), nine pigeons were exposed to two temporal discriminations, each signaled by a different cue. On half of the trials, pigeons learned to choose a red key after a 1.5-s horizontal bar and a green key after a 6-s horizontal bar; on the other half of the trials, they learned to choose a blue key after a 6-s vertical bar and a yellow key after a 24-s vertical bar. During subsequent test trials, they were exposed to the horizontal or vertical bar, for durations ranging from 1.5 to 24 s, and given a choice between novel key combinations: red vs. yellow, or green vs. blue. Results showed a strong effect of sample duration—as the test signal duration increased, preference for green over blue increased and preference for red over yellow decreased. The effect of sample cue was obtained only on the green-blue test trials. These effects are discussed in light of SET and LeT.     

Whammies and double whammies: The effect of length on nonword reading

In the work presented here, the length effect in nonword reading aloud was investigated in order to assess whether that effect is driven by the number of letters in a string or by the number of graphemes in a string. Simulation work with the Dual-Route Cascaded (DRC) model (e.g., Coltheart, Curtis, Atkins, & Haller, 1993; Coltheart & Rastle, 1994) uncovered a surprising finding regarding the length effect; the same result was obtained in an experiment with human subjects. The results are discussed in terms of the DRC model, with particular reference to serial processing and interphoneme inhibition, two properties critical to understanding the effect reported here.     

Changing plans: Dynamic inconsistency and the effect of experience on the reference point

This article presents a new test of a principle of decision making calleddynamic consistency. This principle was tested in an experiment in which participants were asked to make decisions about a second gamble within a sequence of two gambles. Participants were first asked to make a planned choice about the second gamble. The planned choice was madebefore the first gamble was played and was conditioned on the anticipated outcomes of the first gamble.After the first gamble was played, the same participants were asked to make a final choice about the second gamble, conditioned on the experienced outcome of the first gamble. The results showed that participants’ final choices were frequently inconsistent with their plans, even when the anticipated and experienced outcomes were identical. These inconsistencies occurred in a systematic direction. Experiencing an anticipated gain resulted with a change toward risk aversion, and experiencing an anticipated loss resulted in a change toward risk seeking. These results are explained in terms of the effect of actual experience on the reference point used for the evaluation of the decision problem.     

The Obsessive-Compulsive Inventory: development and validation of a short version

This article reports on the development of a revised version of the Obsessive-Compulsive Inventory (OCI; E. B. Foa, M. J. Kozak, P. Salkovskis, M. E. Coles, & N. Amir, 1998), a psychometrically sound, theoretically driven, self-report measure. The revised OCI (OCI-R) improves on the parent version in 3 ways: It eliminates the redundant frequency scale, simplifies the scoring of the subscales, and reduces overlap across subscales. The reliability and validity of the OCI-R were examined in 215 patients with obsessive-compulsive disorder (OCD), 243 patients with other anxiety disorders, and 677 nonanxious individuals. The OCI-R, which contains 18 items and 6 subscales, has retained excellent psychometric properties. The OCI-R and its subscales differentiated well between individuals with and without OCD. Receiver operating characteristic (ROC) analyses demonstrated the usefulness of the OCI-R as a diagnostic tool for screening patients with OCD, utilizing empirically derived cutscores.