Group Cancellation and Resolution

We establish a connection between the geometric methods developed in the combinatorial theory of small cancellation and the propositional resolution calculus. We define a precise correspondence between resolution proofs in logic and diagrams in small cancellation theory, and as a consequence, we derive that a resolution proof is a 2-dimensional process. The isoperimetric function defined on diagrams corresponds to the length of resolution proofs.     

Does prism adaptation affect visual search in spatial neglect patients: A systematic review

Prism adaptation (PA) is a widely used intervention for (visuo‐)spatial neglect. PA‐induced improvements can be assessed by visual search tasks. It remains unclear which outcome measures are the most sensitive for the effects of PA in neglect. In this review, we aimed to evaluate PA effects on visual search measures. A systematic literature search was completed regarding PA intervention studies focusing on patients with neglect using visual search tasks. Information about study content and effectiveness was extracted. Out of 403 identified studies, 30 met the inclusion criteria. The quality of the studies was evaluated: Rankings were moderate‐to‐high for 7, and low for 23 studies. As feature search was only performed by five studies, low‐to‐moderate ranking, we were limited in drawing firm conclusions about the PA effect on feature search. All moderate‐to‐high‐ranking studies investigated cancellation by measuring only omissions or hits. These studies found an overall improvement after PA. Measuring perseverations and total task duration provides more specific information about visual search. The two (low ranking) studies that measured this found an improvement after PA on perseverations and duration (while accuracy improved for one study and remained the same for the other). This review suggests there is an overall effect of PA on visual search, although complex visual search tasks and specific visual search measures are lacking. Suggestions for search measures that give insight in subcomponents of visual search are provided for future studies, such as perseverations, search path intersections, search consistency and using a speed–accuracy trade‐off.     

On Categorical Equivalences of Commutative BCK-algebras

A commutative BCK-algebra with the relative cancellation property is a commutative BCK-algebra (X;*,0) which satisfies the condition: if a ≤ x, a ≤ y and x * a = y * a, then x = y. Such BCK-algebras form a variety, and the category of these BCK-algebras is categorically equivalent to the category of Abelian ℓ-groups whose objects are pairs (G, G ₀), where G is an Abelian ℓ-group, G ₀ is a subset of the positive cone generating G ⁺ such that if u, v ∈ G ₀, then 0 ∨ (u - v) ∈ G ₀, and morphisms are ℓ-group homomorphisms h: (G, G ₀) → (G′,G′₀) with f(G ₀) ⫅ G′₀. Our methods in particular cases give known categorical equivalences of Cornish for conical BCK-algebras and of Mundici for bounded commutative BCK-algebras (= MV-algebras). This revised version was published online in June 2006 with corrections to the Cover Date.     

Evaluating a model of global psychophysical judgments—I: Behavioral properties of summations and productions

The research presented is a partial empirical evaluation of the second author's proposed psychophysical theory [Luce (2002). Psychological Review, 109, 520-532; Luce (2004). Psychological Review, 111, 446-454]. The theory deals with the global percept of subjective intensity, in which there is a psychophysical function Ψ that maps pairs of physical intensities onto the positive real numbers and represents, in an explicit mathematical way, subjective summation and a form of ratio production. A number of behavioral properties have been shown to follow from these specific representations, and in the presence of certain plausible background assumptions these properties are also sufficient for the representations. In four auditory experiments, key behavioral properties of summation over the two ears and a form of generalized ratio production are evaluated empirically. Considerable support is reported for particular forms of Ψ for summations and ratio productions separately. A second article, Steingrimsson and Luce (Journal of Mathematical Psychology, in press), explores the behavioral properties that link summations and productions.     

Additive conjoint isotonic probabilistic models (ADISOP)

The ISOP-model or model of twodimensional or bi-isotonicity (Scheiblechner, 1995) postulates that the probabilities of ordered response categories increase isotonically in the order of subject ability and item easiness. Adding a conventional cancellation axiom for the factors of subjects and items gives the ADISOP model where the c.d.f.s of response categories are functions of an additive item and subject parameter and an ordinal category parameter. Extending cancellation to the interactions of subjects and categories as well as of items and categories (independence axiom of the category factor from the subject and item factor) gives the CADISOP model (completely additive model) in which the parallel c.d.f.s are functions of the sum of subject, item and category parameters. The CADISOP model is very close to the unidimensional version of the polytomous Rasch model with the logistic item/category characteristic(s) replaced by nonparametric axioms and statistics. The axioms, representation theorems and algorithms for model fitting of the additive models are presented.     

Vulnerable Women and Neo-Liberal Globalization: Debt Burdens Undermine Women's Health in the Global South

Contemporary processes of globalization havebeen accompanied by a serious deterioration inthe health of many women across the world. Particularly disturbing is the drastic declinein the health status of many women in theglobal South, as well as some women in theglobal North. This paper argues that thehealth vulnerability of women in the globalSouth is inseparable from their political andeconomic vulnerability. More specifically, itlinks the deteriorating health of many Southernwomen with the neo-liberal economic policiesthat characterize contemporary economicglobalization and argues that this structure issustained by the heavy burden of debtrepayments imposed on many Southern countries. In conclusion, it argues that many Southerndebt obligations are not morally bindingbecause they are not democraticallylegitimate.     

Getting Along and/or Getting Ahead: Differential HEXACO Personality Correlates of Likeability and Popularity among Adolescents

Getting along (i.e. to be liked) and getting ahead (i.e. to be popular) are two fundamental psychological motives that have important consequences for adolescents' well-being. Especially antisocial behavioural tendencies, which are less well covered by the Big Five than by the HEXACO model, have been shown to differentially predict likeability and popularity. In this study, possible differential relations between personality and likeability and popularity were investigated using the HEXACO Simplified Personality Inventory and sociometric measures of likeability and popularity among 552 (12 to 14 years old) adolescents. Results showed that agreeableness was the most important likeability predictor, whereas extraversion (positive), openness to experience, honesty-humility, and agreeableness (all three negative) were the most important popularity predictors. Facet-level analyses revealed that selected HEXACO facets (greed avoidance, fearfulness, social boldness, gentleness, prudence, perfectionism, aesthetic appreciation, and altruism) most strongly—and in opposite directions—differentiated in the prediction of likeability and popularity. Furthermore, none of the expected interactions but several masking and cancellation effects were observed. The results, which are also discussed in light of interpersonal circumplex, resource control strategies, hierarchical differentiation, and socioanalytic frameworks, suggest that—among early adolescents—differential personality predictors may make it difficult to both get along and get ahead. © 2020 The Authors. European Journal of Personality published by John Wiley & Sons Ltd on behalf of European Association of Personality Psychology     

You never know where you are going until you know where you have been: Disorganized search after stroke

Disorders in spatial exploration can be expressed in a disorganized fashion of target cancellation. There is debate regarding whether disorganized search is related to stroke in general, to right brain damage or to unilateral spatial neglect (USN) in particular. In this study, 280 stroke patients and 37 healthy control subjects performed a computerized shape cancellation test. We investigated the number of perseverations and several outcome measures regarding disorganized search: Consistency of search direction (best r), distance between consecutive cancelled targets and intersections with paths between previous cancelled targets. We compared performance between patients with left and right brain damage (L, R) and with and without USN (USN+, USN?), resulting in four subgroups: LUSN?, RUSN?, LUSN+, and RUSN+. Higher numbers of intersections were found for the left brain‐ and right brain‐damaged patients with USN and for the right brain‐damaged patients without USN, compared to healthy control subjects. Furthermore, right brain‐damaged patients with USN showed a higher number of intersections compared to right brain‐damaged patients without USN and compared to left brain‐damaged patients with USN. To conclude, disorganized search was most strongly related to the neglect syndrome, and patients with more severe USN were even more impaired.     

Contingent application of the cancellation editing operation: the role of semantic relatedness between risky outcomes

This article presents findings on the restructuring component of the decision process. Two experiments are described employing hypothetical vacation choice dilemmas. The aim was to explore the conditions under which outcomes common to two risky prospects with the same probabilities of occurrence are or are not cancelled and how consequent decisions are influenced. The design of the options presented to participants was based on pilot work to establish appropriate contexts. The key independent variable was the semantic relatedness between outcomes of the same risky prospect. The main finding was that the participants did not cancel the outcome shared by two prospects when it was semantically related to another outcome within the same prospect. In this case, the prospect with greater risk was chosen significantly more frequently in comparison to when the common outcome was unrelated to other outcomes. An interpretation of the findings is presented in terms of contingent editing processes. Copyright © 2004 John Wiley & Sons, Ltd.     

Temporal order judgements as a sensitive measure of the spatial bias in patients with visuospatial neglect

Visuospatial neglect is not a unitary phenomenon, but can be better considered a syndrome, consisting of a multitude of different spatial and non‐spatial components. In this study, we used a temporal order judgement (TOJ) test in a large sample of stroke patients (n = 73) to scrutinize the contribution of a spatial bias to the performance on shape cancellation and line bisection tests. In the TOJ test, patients were presented with two elements, one in each visual field, after which the one needed to indicate which of the two elements was presented earlier. For each visual field, the presentation of the stimuli was determined by a staircase procedure where the interval between the two stimuli was determined by the performance of the patient. Results indicated that the strength of the spatial bias was strongly correlated with an object cancellation test, but not with a line bisection test. We argue that these findings are explained by differences in the extent to which a spatial bias determines performance on both tasks: In contrast to shape cancellation tests, successful performance on line bisection tests depends primarily on an object‐based, allocentric representation of space, unrelated to any spatial bias in the detection of elements in the contralesional visual field.