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.     

Severity of injuries due to accidental fall across the life span: a retrospective hospital-based study

This retrospective study investigated injuries due to accidental fall across the life span for which 19,593 patients were admitted to the Emergency Unit of the Groningen University Hospital during the period 1990 through 1997. 64% of the accidental falls were found for those in the age range between 10 years and 59 years; however, the proportion of accidental falls with regard to other causes of injuries by age group were the highest in youngsters (infants up to 9 years old) and in elderly persons (over 60 years old), 43% or more of these patients having falls with injuries. The clinically treated patients had on the average a statistically greater Injury Severity Score (7.2) than the outpatients (2.4). The highest percentages of medically treated inpatients were the patients of 60 years and over. Their mean ISS score was about the same for elderly inpatients, but the percentage of clinical treatment increased with age as well as the mortality. 30% of the injuries were found in the lower extremities and 30% in the upper extremities. Bone fracture was statistically significantly the major (36%) injury followed by contusion (20%). 34% of the accidental falls occurred at home, and statistically significantly more females, 50 years of age and older, were injured than males.     

Injuries due to school sports accidents in 4 to 13-yr.-old children

505 kindergarten and primary school children from 4 to 13 years of age were treated for school sports injuries during the period 1990-1997. The incidence of injuries increased statistically significantly from .5 per 1,000 children 4- to 5-yr.-old to 4.8 injured children per 1,000 in 12- to 13-yr.-old. 59% of the injuries involved upper extremities; 35% of these were in the wrist region. 33.5% of the injuries were of the lower extremities, with 50% being of the feet and 36.4% of the ankle. Accidental falls were the main situation (53%) in which school sport accidents occurred. Nearly 65% of these accidental falls occurred at the ground level; the remaining accidents (35%) occurred when the child was working on an apparatus, e.g., parallel bars, balancing beam, side horse. The 4- to 5-yr.-old children were the most vulnerable to accidental fall (67%). A statistically significant increase in injuries in ball sports was observed from 4- to 5-yr.-olds (0%) to the 12- to 13-yr.-olds (28%).     

Personality in proportion: a bipolar proportional scale for personality assessments and its consequences for trait structure

Trait structures resulting from personality assessments on Likert scales are affected by the additive and multiplicative transformations implied in interval scaling and correlational analysis. The effect comes into view on selecting a plausible alternative scale. To this end, we propose a bipolar bounded scale ranging from -1 to +1 representing an underlying process in which the assessor would review and discount positive and negative behavioral instances of a trait. As an appropriate index of likeness between variables X and Y, we propose LXY = SigmaXY/N, the average of the raw scores cross products. Using this index, we carried out a raw scores principal component analysis on data consisting of 133 participants who had each been rated by 5 assessors including self on 914 items. Contrary to the Big-Five structure that was found in these data on standard analysis, the results showed a relatively large first principal component F1 and 2 very small ones, F2 and F3. The sizes LFF=SigmaF2/N, the averages of the squared component scores, were modest to small. It thus appears that the scale, bipolar proportional versus standard, has a profound impact on the size and structure of personality assessments. The dissimilarity remains on analyzing self-ratings rather than averaged (over the 5 assessors) ratings.     

Evidence that baroreflex feedback influences long-term incidental visual memory in men

Sympathetic nervous system (SNS) activity at the time of acquisition is associated with human memory. However, rather than SNS activity per se, it may be afferent baroreflex feedback that is responsible for this effect. A pharmacological design was employed to unload (SNP, sodium nitro-prusside) and load (norepinephrine) baroreceptors. In addition to two placebo periods, epinephrine and esmolol (a peripherally acting beta1-blocker) served as control conditions for altered cardiac perception. During drug infusion blood pressure, heart rate, and perception of heartbeat were tested. Twenty-four healthy men were participated. The participants viewed emotional slides while their electromyographic eye blink responses to random noise bursts were measured (affective startle modulation paradigm) to determine potential drug impact on emotional processing. Subjects were not informed that memory testing would take place after 4 weeks. Drugs did not impact startle, thus indicating unbiased emotional processing at the time of acquisition. Norepinephrine had no effect on heartbeat perception, but improved (p = .002) recognition memory. SNP (p = .0001) increased heartbeat perception but impaired (p = .038) recognition memory. Epinephrine, on the other hand, increased heartbeat perception (p = .0001) yet did not impair but partially improve memory (effect on high arousing pictures only: p = .05). Heartbeat perception in the placebo condition did not correlate with recognition memory (p's > .5). We suggest that baroreflex unloading, with subsequent feedback activation of the SNS, impairs long-term incidental visual recognition memory in humans while baroreflex loading enhances it. Further, we propose that these memory effects are neither secondary to cardiac sensations that accompany SNS activation nor to altered emotional picture processing at the time of acquisition.     

A case of extreme simplicity of the core matrix in three-mode principal components analysis

In three-mode Principal Components Analysis, theP ×Q ×R core matrixG can be transformed to simple structure before it is interpreted. It is well-known that, whenP=QR,G can be transformed to the identity matrix, which implies that all elements become equal to values specified a priori. In the present paper it is shown that, whenP=QR − 1,G can be transformed to have nearly all elements equal to values spectified a priori. A cllsed-form solution for this transformation is offered. Theoretical and practical implications of this simple structure transformation ofG are discussed. Constructive comments from anonymous reviewers are gratefully acknowledged.     

Medical Ethics Research Between Theory and Practice

The main object of criticism of present-day medical ethics is the standard view of the relationship between theory and practice. Medical ethics is more than the application of moral theories and principles, and health care is more than the domain of application of moral theories. Moral theories and principles are necessarily abstract, and therefore fail to take account of the sometimes idiosyncratic reality of clinical work and the actual experiences of practitioners. Suggestions to remedy the illnesses of contemporary medical ethics focus on re-establishing the connection between the internal and external morality of medicine. This article discusses the question how to develop a theoretical perspective on medical ethical issues that connects philosophical reflection with the everyday realities of medical practice. Four steps in a comprehensive approach of medical ethics research are distinguished: (1) examine health care contexts in order to obtain a better understanding of the internal morality of these practices; this requires empirical research; (2) analyze and interpret the external morality governing health care practices; sociological study of prevalent values, norms, and attitudes concerning medical-ethical issues is required; (3) creation of new theoretical perspectives on health care practices; Jensen's theory of healthcare practices will be useful here; (4) develop a new conception of bioethics that illuminates and clarifies the complex interaction between the internal and external morality of health care practices. Hermeneutical ethics can be helpful for integrating the experiences disclosed in the empirical ethical studies, as well as utilizing the insights gained from describing the value-contexts of health care practices. For a critical and normative perspective, hermeneutical ethics has to examine and explain the moral experiences uncovered, in order to understand what they tell us.     

Orthogonal procrustes rotation for two or more matrices

Necessary and sufficient conditions for rotating matrices to maximal agreement in the least-squares sense are discussed. A theorem by Fischer and Roppert, which solves the case of two matrices, is given a more straightforward proof. A sufficient condition for a best least-squares fit for more than two matrices is formulated and shown to be not necessary. In addition, necessary conditions suggested by Kristof and Wingersky are shown to be not sufficient. A rotation procedure that is an alternative to the one by Kristof and Wingersky is presented. Upper bounds are derived for determining the extent to which the procedure falls short of attaining the best least-squares fit. The problem of scaling matrices to maximal agreement is discussed. Modifications of Gower's method of generalized Procrustes analysis are suggested.     

Effects of Salient Multiple Identities on Women's Performance Under Mathematics Stereotype Threat

Previous research on affective extremity and social identity complexity suggested that women's mathematics stereotype threat might be alleviated by reminding individual women of their multiple roles and identities, most of which would presumably be unrelated and thus impervious to negative stereotypes regarding math performance. To test this hypothesis, we primed the relevant stereotype and then asked men and women college students to draw self-concept maps with many or few nodes. When they drew no maps or maps with few nodes, highly math-identified women scored significantly worse than highly math-identified men on a subsequent Graduate Record Examination-like math test, but when they drew maps with many nodes, they scored as well as those men. Theoretical and practical implications of the results are discussed.     

Sufficient conditions for uniqueness in Candecomp/Parafac and Indscal with random component matrices

A key feature of the analysis of three-way arrays by Candecomp/Parafac is the essential uniqueness of the trilinear decomposition. We examine the uniqueness of the Candecomp/Parafac and Indscal decompositions. In the latter, the array to be decomposed has symmetric slices. We consider the case where two component matrices are randomly sampled from a continuous distribution, and the third component matrix has full column rank. In this context, we obtain almost sure sufficient uniqueness conditions for the Candecomp/Parafac and Indscal models separately, involving only the order of the three-way array and the number of components in the decomposition. Both uniqueness conditions are closer to necessity than the classical uniqueness condition by Kruskal. Part of this research was supported by (1) the Flemish Government: (a) Research Council K.U. Leuven: GOA-MEFISTO-666, GOA-Ambiorics, (b) F.W.O. project G.0240.99, (c) F.W.O. Research Communities ICCoS and ANMMM, (d) Tournesol project T2004.13; and (2) the Belgian Federal Science Policy Office: IUAP P5/22. Lieven De Lathauwer holds a permanent research position with the French Centre National de la Recherche Scientifique (C.N.R.S.). He also holds an honorary research position with the K.U. Leuven, Leuven, Belgium.