The burden of calcific aortic stenosis: what's behind?

In Western countries, calcific aortic valve stenosis (CAS) is widely common, representing the third cause of death among cardiovascular diseases (CVD). The burden of CAS is high, with an increasing prevalence rate related to age. An efficient medical treatment, according to guidelines, lacks to prevent the development and to reduce the progression of CAS. In this context, due to the aging population and the lack of effective medical management, the prevalence is expected to double-triple within the next decades. In our review, we aim to provide an overview of the underlying mechanisms of pathogenesis and the current state of the art regarding pathophysiological insights and novel potential therapeutic targets.

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

P415 NEUROGENIC STRESS CARDIOMYOPATHY

Case Report

Caucasian 84–years–old woman was found on the floor at her house and was brought to the ED of Policlinico Umberto I with the diagnosis of cranial trauma following a syncope. A head CT showed right paramedian fracture of the occipital bone, left frontal subarachnoid hemorrhage and left frontal subdural hemorrhage. The neurosurgeon gave no indication to urgent evacuation of the hemorrhage. Then elevation of cardiac enzymes and ST–segment elevation at the EKG were found but due to the state of the patient a coronary angiography was not performed and the patient was transferred to the CCU. The patient was hemodynamically stable with right hemiplegia. The EKG showed rapid ventricular rate atrial fibrillation with ST segment elevation in inferior and lateral leads with T wave inversion in the same leads and elevated serum troponin levels. ETT showed: EF 30% with a global reduction of left ventricular systolic function with diffuse akinesis. Intravenous therapy with mannitol and corticosteroids for perilesional oedema was started. Beta blockers and a class III antiarrhythmic drug were also started, but hemodynamic conditions declined and acute kidney failure occurred with progressive hypotension followed by cardiogenic shock. The patient had an episode of nonsustained ventricular tachycardia treated with antiarrhythmic drugs and magnesium sulfate. The EKG started to show a normalization of the repolarization phase with regression of ST segment elevation and persistent T wave inversion.The patient’s neurological conditions were complicated with epileptic seizures.On the fifth day of hospitalization the TTE revealed a slight improvement of global systolic function and the presence of an apical thrombotic apposition.The patient’s clinical conditions worsened and led to exitus.

Discussion

The interpretation of this patient’s history was made more difficult by the lack of witnesses of the trauma.The patient’s age, her history of hypertension and the presence of regional wall motion abnormalities at the TTE suggested the presence of CAD. On the other side the atrial fibrillation could hint a primitive cerebral event. This case report shows the potentially severe cardiac manifestations of cerebral hemorrhage and the necessity to consider cerebrovascular events as the cause of EKG changes mimicking a myocardial infarction, cardiac enzymes elevation and ventricular wall motion abnormalities, in order to avoid inappropriate or delated therapies.

Visual similarity modulates visual size contrast

Perception is relational: object properties are perceived in comparison to the spatiotemporal context rather than absolutely. This principle predicts well known contrast effects: For instance, the same sphere will feel smaller after feeling a larger sphere and larger after feeling a smaller sphere (the Uznadze effect). In a series of experiments, we used a visual version of the Uznadze effect to test whether such contrast effects can be modulated by organizational factors, such as the similarity between the contrasting inducer stimulus and the contrasted induced stimulus. We report that this is indeed the case: size contrast is attenuated for inducer-inducing pairs having different 3D shapes, orientations, and even - surprisingly - color and lightness, in comparison to equivalent conditions where these features are the same. These findings complement related work in revealing basic mechanisms for fine-tuning local interactions in space-time in accord to the global stimulus context.

Adhésion et représentations des antidépresseurs chez des patients hospitalisés pour épisode dépressif majeur

Introduction

La non-adhésion diminue largement l’efficacité des antidépresseurs [1,2], dont la représentation évolue dans un contexte particulièrement défiant et médiatiquement tendu.

Objectif

L’objectif de cette étude est de :

– évaluer l’adhésion aux antidépresseurs chez des patients hospitalisés pour épisode dépressif majeur ;

– explorer les représentations que les patients ont des antidépresseurs et de la dépression, ainsi que la perception de la stigmatisation aux troubles mentaux ;

– analyser la relation entre les attitudes face aux antidépresseurs et des paramètres sociodémographiques et cliniques.

Méthode

L’adhérence était évaluée chez 40 patients en utilisant la version courte du Drug Attitude Inventory (DAI-10), complétée par un questionnaire mesurant les connaissances, craintes, impact des média et stigmatisation liés aux antidépresseurs. Des entretiens d’investigation étaient ensuite menés à l’aide de celui-ci.

Résultats

L’âge moyen de l’échantillon est de 43 ans, dont 27 % d’homme. Il s’agit d’un premier épisode pour 40 % des patients. La médiane du DAI est de 3,5 (échelle de −10 à +10), et 30 % des patients ne sont pas adhérents. Les hommes de l’échantillon ont une plus mauvaise représentation des antidépresseurs (−2 VS 4 ; U de Mann-Whitney = 90,50 ; p = 0,0035). Soixante-dix pour cent des patients ont des craintes par rapport à leur antidépresseur (prise de poids et dépendance au premier rang). Vingt pour cent des patients n’ont pas dit à leur entourage qu’ils prenaient des médicaments contre la dépression.

Discussion

Une intervention à de multiples niveaux pourrait augmenter les connaissances des patients ainsi que de l’opinion publique [3]. Une collaboration spécifique entre journalistes et psychiatres permettrait une meilleure connaissance et une diffusion plus représentative des enjeux de santé mentale dans les média [4]. Des actions de santé publique et initiatives citoyennes pourraient aussi être profitables aux patients.

Conclusion

L’adhérence aux antidépresseurs peut largement être améliorée, la stigmatisation restant une barrière aux traitements et à la prise en charge.

Pulsed source of spectrally uncorrelated and indistinguishable photons at telecom wavelengths

We report on the generation of indistinguishable photon pairs at telecom wavelengths based on a type-II parametric down conversion process in a periodically poled potassium titanyl phosphate (PPKTP) crystal. The phase matching, pump laser characteristics and coupling geometry are optimised to obtain spectrally uncorrelated photons with high coupling efficiencies. Four photons are generated by a counter-propagating pump in the same crystal and anlysed via two photon interference experiments between photons from each pair source as well as joint spectral and g((2)) measurements. We obtain a spectral purity of 0.91 and coupling efficiencies around 90% for all four photons without any filtering. These pure indistinguishable photon sources at telecom wavelengths are perfectly adapted for quantum network demonstrations and other multi-photon protocols.

Phase III development of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire module for women undergoing breast reconstruction

Background

Comprehensive outcome assessments after breast reconstruction (BRR) require surgery-specific patient-reported outcome measures. The aims of this study were to assess the relevance, acceptability and redundancy of questions/items (phase III pretesting) of a new BRR questionnaire evaluating patients' health-related quality of life before and after BRR. Phase III occurred in collaboration with the European Organization for Research and Treatment of Cancer (EORTC) following earlier development phases that identified 31 items.

Methods

The EORTC BRR subgroup applied decision-making rules to each question according to eight EORTC criteria. A total of 197 patients (from the UK, Austria, Belgium, Italy and Sweden) were recruited. Forty-seven patients completed pre- and post-BRR questionnaires prospectively, and 150 reported post-BRR questionnaires only retrospectively. Qualitative debriefing interviews were undertaken in 189 patients. Preliminary psychometric analyses were performed.

Results

Thirty-one items fulfilled ‘relevance’, with none producing ‘difficulties’. Ten items were not a priority for 10 per cent of respondents. Of these, two questions concerning muscle twitching in the affected breast and problem with donor-site swelling were deleted. Three redundant items were deleted: weakness in arm, which correlated significantly to the Quality of Life Questionnaire (QLQ) BR23 breast questionnaire, and shape and colour of the affected nipple. Descriptive statistics reduced the module to 26 items conceptualized into three provisional scales (disease treatment/surgery-related symptoms, sexuality and cosmetic outcome) within the newly completed questionnaire, EORTC QLQ-BRR26.

Conclusion

The QLQ-BRR26 is available for psychometric validation in a large-field international sample. The intended use for QLQ-BRR26 is alongside EORTC QLQ-C30 and QLQ-BR23, in women treated by mastectomy for breast cancer and undergoing all types of BRR.

High efficiency coupling of photon pairs in practice

Multi-photon and quantum communication experiments such as loophole-free Bell tests and device independent quantum key distribution require entangled photon sources which display high coupling efficiency. In this paper we put forward a simple quantum theoretical model which allows the experimenter to design a source with high pair coupling efficiency. In particular we apply this approach to a situation where high coupling has not been previously obtained: we demonstrate a symmetric coupling efficiency of more than 80% in a highly frequency non-degenerate configuration. Furthermore, we demonstrate this technique in a broad range of configurations, i.e. in continuous wave and pulsed pump regimes, and for different nonlinear crystals.

[Differential indications for psychotherapies in borderline personality disorder]

BACKGROUND

Borderline personality disorder (BPD) accounts for 10% of outpatient psychiatric practice. The risk of suicide attempts is high and the psychosocial impairment significant. Different theoretical streams have suggested psychotherapeutical approaches for BPD.

OBJECTIVE

to examine the efficacy of psychotherapy for BPD patients on affective symptoms, behavioural outcomes, interpersonal and social functioning, as well as BPD criteria.

METHODS

We reviewed the medical literature from 1990 to 2008 on Medline by combining the following keywords "borderline personality disorder" and "psychotherapy" (inclusion criteria). We restricted the analysis to "randomised control trial" or "meta analysis".

RESULTS

Of the 39 abstracts that came out from the search, we selected 17 (44%) after applying the exclusion criteria. According to our review, different types of psychotherapies have shown some efficacy on reducing affective symptoms and BPD criteria, as well as improving behavioural outcomes and psychosocial functioning. Dialectical behavioural therapy presents the best-documented efficacy, notably on reducing self-mutilating and suicidal behaviours (five randomized controlled trials [RCT]). Mentalization based treatment seems to be efficient on the four types of outcomes, but has been the object of only one RCT. Finally, some evidence suggests that Manual Assisted Cognitive Treatment and Systems Training for Emotional Predictability and Problem Solving are the most cost-effective and easiest to be implemented.

CONCLUSION

According to our review, some evidence supports an efficiency of psychotherapies in the management of several features of BPD. It is likely that, depending on the target symptoms, one type of therapy might be more efficient than another. The acceptability of these long-term treatments is however unknown.

Hyperentangled mixed phased Dicke states: optical design and detection

A recently introduced family of multipartite entangled states, the 4-qubit phased Dicke states, has been created by 2-photon hyperentanglement. Our experimental method allows high state fidelity and generation rate. By introducing quantum noise in the multipartite system in a controlled way, we have tested the robustness of these states. To this purpose the entanglement of the resulting multipartite entangled mixed states has been verified by using a new kind of structural witness.

Protective role of protein C inhibitor in monocrotaline-induced pulmonary hypertension

BACKGROUND

Protein C inhibitor (PCI) plays a role in multiple biological processes including fertilization, coagulation, fibrinolysis and kinin systems.

OBJECTIVES

We hypothesized that PCI participates in the pathogenesis of pulmonary hypertension. To demonstrate this, we compared the development of pulmonary hypertension in mice overexpressing PCI in the lung with wild-type (WT) mice. Pulmonary hypertension was induced by s.c. injection of 600 mg kg-1 of monocrotaline weekly for 8 weeks.

RESULTS

Right ventricular arterial pressure was significantly increased in monocrotaline-treated WT mice compared with that in monocrotaline-treated transgenic mice. Bronchoalveolar lavage fluid (BALF) levels of thrombin-antithrombin complex, monocyte chemoattractant protein-1 and platelet-derived growth factor, and the plasma level of tumor necrosis factor-alpha were significantly increased in monocrotaline-treated WT mice as compared with monocrotaline-treated PCI transgenic mice. Increased level of PCI-thrombin complex was detected in BALF from monocrotaline-treated PCI transgenic mice as compared with saline-treated PCI transgenic mice.

CONCLUSIONS

This study showed that increased expression of PCI in the lung is protective against monocrotaline-induced pulmonary hypertension, suggesting a potential beneficial effect of PCI for the therapy of this disease.

Different atrial regional patterns of activation during atrial fibrillation: is there any relationship with the anatomy?

Right atrial (RA) mapping has been recently more carefully examined in patients with idiopathic atrial fibrillation (AF) in order to improve radiofrequency (RF) catheter-mediated ablation lines to control recurrences. The aim of this study was to map right atrial activation during AF to analyze relationship between anatomy and atrial activation for specific sites. Twenty-four patients with recurrent, drug-refractory, paroxysmal AF underwent an extensive mapping of the RA before attempting RF linear lesion catheter ablation. A typical pattern of atrial activation was recorded in all patients which was consistent with a more regular activity on the trabeculated right atrium (type I AF) and a more fragmented and complex activation on the posterior and the anterior septum (type II and III AF). This paper helps to understand the influence of the anatomic barriers to atrial activation during atrial fibrillation.

When does action resist visual illusions?

Over the past decade, many studies of non-pathological individuals have reported functional dissociations between perceptual judgments and motor responses. These results suggested an interpretation of the ventral and dorsal streams in the primate visual system as independent modules for visual awareness and the visual guidance of actions. However, recent comparisons of perception and grasping responses in size-contrast displays have been widely reported to show that apparent dissociations are actually experimental artifacts. An overview of the literature suggests that the issue of visuomotor dissociations in healthy individuals is far from settled. Some results suggest that immunity from visual illusions might be found when task requirements emphasize observer-relative reference frames. These results suggest that the functional specialization of the two visual subsystems might be less rigid than originally posited.

Paradoxical rest

Paradoxical absence of motion in a rotating pattern is reported. The effect requires that the motion of the paradoxically stationary figure be underspecified by local motion signals, and that the paradoxically stationary figure be well segregated. This is consistent with proposals that figural segregation affects the integration of local motion signals.

Amodal completion of partly occluded surfaces: is there a mosaic stage?

Recent investigators have proposed that amodal completion is a sequential process requiring a preliminary mosaic stage. Results of 6 studies of the time course of completion processes show support for this mosaic-first view with pictorial displays, but not with displays involving occlusion specified by binocular parallax or when pictorial displays were observed monocularly. These results still do not rule out the mosaic-first view. A parallel model, however, can account more economically for the available data.

Amodal completion of partly occluded surfaces: is there a mosaic stage?

Recent investigators have proposed that amodal completion is a sequential process requiring a preliminary mosaic stage. Results of 6 studies of the time course of completion processes show support for this mosaic-first view with pictorial displays, but not with displays involving occlusion specified by binocular parallax or when pictorial displays were observed monocularly. These results still do not rule out the mosaic-first view. A parallel model, however, can account more economically for the available data.

Lightness, equivalent backgrounds, and anchoring

Observers compared two center/surround configurations haploscopically. One configuration consisted of a standard surface surrounded by two, three, or four surfaces, each with a different luminance. The other configuration consisted of a comparison surface surrounded by a single annulus that varied in luminance. Center surfaces always had the same luminance but only appeared to have the same lightness with certain annuli (equivalent backgrounds). For most displays, the luminance needed to obtain an equivalent background was close to the highest luminance in the standards surround configuration. Models based on the space-average luminance or the space-average contrast of the standard surround configuration yielded poorer fits. Implications for computational models of lightness and for candidate solutions to the anchoring problem are discussed.

The perception of surface folding in static and animated displays

How do we interpret outline drawings of surfaces? Although pictorial depictions are projectively ambiguous, observers demonstrate definite preferences of interpretation. Additionally, they commit typical errors. A study is reported of one specific arrangement of surfaces as it is represented in outline drawings, namely the arrangement that results when two arbitrary surfaces are joined at a common edge to form an angle in 3-D ('phenomenic folding'). With some of these arrangements, observers report that the angle formed by the two surfaces is zero (complete folding). With others, they report that the angles are greater than zero (incomplete folding). Both interpretations are actually valid. Several investigators have proposed that observer preferences such as these are due t a tendency to prefer a 3-D interpretation that will make the depicted 3-D shape regular. Three experiments were performed to test this regularisation hypothesis. In the first, observers were shown pairs of four-sided polygons joined at one equal side. Their task was to imagine how the smaller polygon could be folded completely towards the larger, and, subsequently, to report on its position after the ('mental folding'). Reported positions were consistent with 3-D interpretations that caused figural regularisations, In the second and third experiments, observers were shown drawings of diamonds and parallelograms folded along a number of differently positioned and oriented segment ('folding edge'). Their task was to estimate verbally the extent of the dihedral angle formed by the two surfaces. Results indicated that the perception of incomplete folding is determined by 3-D interpretation of the orientation of the drawing with respect of the picture plane. In a fourth experiment, observers were asked whether projective equivalences might be disambiguated by animating two kinds of displays that yield the 'incomplete folding' effect but that should be distinguishable on the basis of the trajectories of the vertexes of the folding parts. Results demonstrated that even in these conditions observers are unable to interpret the foldings correctly. These results might be taken to indicate that projective, static information leading to a simpler and more regular interpretation of the display can prevail over explicit motion information that should force the system to achieve a nonregular solution.

Lightness contrast in CRT and paper-and-illuminant displays

The increased use of CRT monitors for displaying and controlling stimuli in studies of surface color poses problems of comparability with data obtained with traditional paper-and-illuminant methods. A review of comparable studies using the two methodologies revealed that CRT studies tend to report larger contrast effects. To investigate factors that may be responsible for this difference, simultaneous lightness contrast was measured using both CRT and paper-and-illuminant presentations. The spatial distribution of luminance in the whole field of view and the visual angles subtended by the displays were controlled. The CRT presentation yielded contrast effects twice as big as those measured for a paper surface in a homogeneously illuminated room. However, a paper display under Gelb lighting yielded almost exactly the same effect size as that measured in the CRT presentation. These results demonstrate that contrast effects in both modes of presentation are affected by the spatial distribution of luminance beyond the basic experimental stimuli.

Failures of lightness constancy, edge integration, and local edge enhancement

In a CRT simulation of the "edge-substitution" paradigm [Gilchrist (1988) Perception & Psychophysics, 43, 415-424], observers adjusted the apparent reflectance (lightness) of a test surface to match incremental or decremental standards. Matches suggested that two factors contributed to the observed failures of lightness constancy: (1) the interpretation of the scene in terms of illumination and reflectance edges and their corresponding integration, and (2) edge-enhancement (the "crispening" effect) due to the local surround.

[Percutaneous approach in the use of subclavian vein in pacemaker implantation]

BACKGROUND AND METHODS

We analyzed the complications of 1729 pacemakers implants (from October 1980 to December 1992) divided according to the way of leads insertion. The approaches from the subclavian vein was used in 1220 cases, the cephalic vein was used in 431 implants and the external jugular vein in 78.

RESULTS

Major complications were: pocket bleeding (108 cases), pocket erosion (15 cases), infection (2 cases), lead fracture (5 cases), lead dislodgement (20 cases), pneumothorax (4 cases, only for subclavian puncture). There were no significative differences in the complications between the three approaches. On the other hand, the subclavian puncture reduces the time of the procedure, is less traumatic and allows to insert and to position several leads.

CONCLUSIONS

We suggest to use the subclavian vein approach as first choice to implant one or more leads, being this way safe and fast.

Selectivity, scope, and simplicity of models: A lesson from fitting judgments of perceived depth

When comparing psychological models a researcher should assess their relative selectivity, scope, and simplicity. The third of these considerations can be measured by the models' parameter counts or equation length, the second by their ability to fit random data, and the first by their differential ability to fit patterned data over random data. These conclusions are based on exploration of integration models reflecting depth judgments. Replication of Massaro's (1988a) results revealed an additive model (Bruno & Cutting, 1988), and Massaro's fuzzy-logical model of perception (FLMP) fit data equally well, but further exploration showed that the FLMP fit random data better. The FLMP's successes may reflect not its sensitivity in capturing psychological process but its scope in fitting any data and its complexity as measured by equation length.

Fibrinopeptide A excretion in urine: a marker of the cumulative thrombin activity in stable versus unstable angina patients

Plasma levels and 24-hour urine excretion of fibrinopeptide A were measured in a consecutive series of 179 patients with angina pectoris. Sixty-four patients had stable angina and 115 patients had unstable angina. Urine was collected over 24 hours the day before coronary arteriography, and blood samples were taken at the end of urine collection. When the values of fibrinopeptide A in plasma and in the 24-hour urine specimens were compared, no significant correlation was found in patients with either stable (rs = 0.16, difference not significant) and unstable (rs = 0.07, difference not significant) angina. The concentrations of fibrinopeptide A in the plasma did not differ significantly when patients with stable angina (range 0.1 to 82.6, median 7.4 ng/mL) were compared with patients with unstable angina (range 0.2 to 61.7, median 14 ng/mL, p = 0.055), whereas fibrinopeptide A 24-hour urinary excretion was significantly higher in patients with unstable angina (range 0.3 to 38.1, median 11.8 micrograms/24 hr) than in patients with stable angina (range 0.4 to 38.1, median 3.8 micrograms/24 hr, p less than 0.001). Twenty-four-hour urine excretion of fibrinopeptide A in patients with unstable angina and angiographically documented intracoronary thrombi were higher than the corresponding values in patients with unstable angina without such angiographic characteristic (p less than 0.001). The largest increase in plasma and urine concentration of fibrinopeptide A was observed in patients whose first episode of angina at rest occurred within the previous 48 hours. We conclude that the cumulative thrombin activity, assessed by 24-hour urinary excretion of fibrinopeptide A, is a more useful index, compared with single fibrinopeptide A measurement in plasma, for discriminating between patients with stable and with unstable angina pectoris.

Illusory figures based on local kinematics

A new type of motion-induced illusory figure determined by local kinematic information is investigated. The new figure is induced by radial line patterns subjected to either figure motion (the lines change as if they were stationary and a triangle was rotating in front of them) or background motion (the lines change as if they were being rotated behind a stationary triangle). Although the two kinds of motion are equivalent from the viewpoint of relative displacements, perceptually they yield very different results. With background motion, observers tend to perceive rigid figures that have a triangular shape. With figure motion, observers report seeing deforming figures with shapes that vary depending on the number of lines in the display. We consider two alternative accounts for this asymmetry which we term the background superiority effect (BSE). The first account proposes that the effect is due to retinal persistence and to figure stability. Against this line of explanation, we demonstrate that observers also see rigid triangular shapes in displays where both the figure and the radial lines rotate (double motion displays). The second account proposes that the effect depends on the availability of local kinematic information constraining contour orientation. This second line of explanation is consistent with observers' reports of bowed edges in double motion displays rotating in phase or in counterphase. Candidate mechanisms for extracting local kinematic information are discussed.

Identifying contours from occlusion events

Surface contours specified by occlusion events that varied in density, velocity, and type of motion (rotation or translation) were examined in four experiments. As a fourth experimental factor, there were both figure-motion trials (the occluding surface moved over a stationary background) and background-motion trials (the background moved behind a stationary surface) in each experiment. Displays contained line patterns and rotary motion (Experiment 1), line patterns and translatory motion (Experiment 2), textured surfaces and rotary motion (Experiment 3), and textured surfaces and translatory motion (Experiment 4). Results indicate that contour identifications are more accurate with translation than with rotation, and that background-motion trials are generally easier than figure-motion trials. Although density in all experiments affected identifications in both background- and figure-motion trials, velocity did so in Experiment 4 only. In Experiments 1, 2, and 3, velocity affected identifications in background-motion trials but not in figure-motion trials. In Experiments 3 and 4, the rate of accretion and deletion of texture was a poor predictor of identification accuracy. These results are not consistent with previous accounts of contour perception from occlusion events, and may reflect an involvement of ocular pursuit as a mechanism for registering contour information.

Usefulness of the hyperventilation test in stable exertional angina pectoris in selecting medical therapy

To assess the prevalence of abnormal coronary vasoconstriction in stable exertional angina and to evaluate whether the presence of increased coronary tone may have therapeutic implications, we studied 83 consecutive patients with typical exertional angina, positive response to exercise stress testing and documented coronary artery disease. Abnormal coronary vasoconstriction was induced by a hyperventilation test in 16 patients (group I) while the remaining 67 had a negative response (group II). No differences were observed between the 2 groups with regard to clinical, exercise and angiographic data. All group I patients and 16 patients in group II repeated hyperventilation and exercise tests after the administration of dihydropyridine-type calcium antagonists (7 patients nifedipine, 9 patients felodipine). After treatment 15 of 16 group I patients had a negative response to the hyperventilation test. The total exercise duration was significantly increased (278 +/- 183 vs 554 +/- 248 seconds; p less than 0.001) with higher values of rate pressure product at peak exercise (168 +/- 47 vs 235 +/- 67 mm Hg x beats/min/100; p less than 0.0025). In group II no significant differences were observed between pre- and posttreatment values for total exercise duration (244 +/- 210 vs 308 +/- 243 seconds) and rate pressure product at peak exercise (170 +/- 46 vs 188 +/- 56 mm Hg x beats/min/100). These data show that the hyperventilation test can be used to select a subset of patients with stable exertional angina and detectable abnormal coronary vasoconstriction who will improve their exercise tolerance with coronary vasodilator treatment.

Additivity, subadditivity, and the use of visual information: a reply to Massaro (1988)

Previously we (Bruno & Cutting, 1988) explored the perception of spatial relations among objects laid out in a computer-generated environment. In his commentary on our article, Massaro (1988) raised several issues. The most important is from his reanalysis, which indicated that--because of a subadditive trend in the results--additive and multiplicative strategies fit our data in Experiment 1 about equally well. In reply, we performed a different analysis. Results corroborate subadditivity--and hence multiplicative information combination--in Experiment 1 but provide no evidence for it in Experiments 2 and 3. On the whole, then, the results still support additivity more strongly than any other combination rule and thus support our notion of minimodularity.

Minimodularity and the perception of layout

In natural vision, information overspecifies the relative distances between objects and their layout in three dimensions. Directed perception applies (Cutting, 1986), rather than direct or indirect perception, because any single source of information (or cue) might be adequate to reveal relative depth (or local depth order), but many are present and useful to observers. Such overspecification presents the theoretical problem of how perceivers use this multiplicity of information to arrive at a unitary appreciation of distance between objects in the environment. This article examines three models of directed perception: selection, in which only one source of information is used; addition, in which all sources are used in simple combination; and multiplication, in which interactions among sources can occur. To monocular spatial information, using all combinations of the presence or absence of relative size, height in the projection plane, occlusion, and motion parallax. Visual stimuli were computer generated and consisted of three untextured parallel planes arranged in depth. Three tasks were used: one of magnitude estimation of exocentric distance within a stimulus, one of dissimilarity judgment in how a pair of stimuli revealed depth, and one of choice judgment within a pair as to which one revealed depth best. Grouped and individual results of the one direct and two indirect scaling tasks suggest that perceivers use these sources of information in an additive fashion. That is, one source (or cue) is generally substitutable for another, and the more sources that are present, the more depth is revealed. This pattern of results suggests independent use of information by four separate, functional subsystems within the visual system, here called minimodules. Evidence for and advantages of minimodularity are discussed.