Possible worlds semantics: A research program that cannot fail?

Providing a possible worlds semantics for a logic involves choosing a class of possible worlds models, and setting up a truth definition connecting formulas of the logic with statements about these models. This scheme is so flexible that a danger arises: perhaps, any (reasonable) logic whatsoever can be modelled in this way. Thus, the enterprise would lose its essential tension. Fortunately, it may be shown that the so-called incompleteness-examples from modal logic resist possible worlds modelling, even in the above wider sense. More systematically, we investigate the interplay of truth definitions and model conditions, proving a preservation theorem characterizing those types of truth definition which generate the minimal modal logic.     

Logical semantics as an empirical science

Exact philosophy consists of various disciplines scattered and separated. Formal semantics and philosophy of science are good examples of two such disciplines. The aim of this paper is to show that there is possible to find some integrating bridge topics between the two fields, and to show how insights from the one are illuminating and suggestive in the other.     

Disentangling Discrimination: Victim Characteristics as Determinants of the Perception of Behavior as Racist or Sexist

The present experiment examined the impact of victim characteristics on the judgment of behavior as being sexist or racist. Freshmen from the University of Amsterdam read eight scenarios describing instances of everyday discrimination. The race, gender, and socioeconomic status (SES) of the victims in the scenarios were varied systematically. Each scenario was followed by three consecutive questionnaires designed to assess the degree to which research participants perceived the behavior of the agent as racist, sexist, or otherwise. The asymmetry hypothesis for blacks of high and low SES was confirmed Blacks of low SES were more often considered to be victims of racism than blacks of high SES. However, contrary to the asymmetry hypothesis, we found that women of high rather than low SES were more likely to be considered victims of sexism. This finding is inconsistent with other results, and demonstrates that it is not always the less empowered group that is judged as being the most discriminated against. Further, this study demonstrates the relevancy of victim's SES in discrimination research. Finally, the importance of disentangling sexist and racist elements of discrimination is stressed, especially in research involving black women.     

Reduced K+ Channel Inactivation, Spike Broadening, and After-Hyperpolarization in Kvβ1.1-Deficient Mice with Impaired Learning

A-type K⁺ channels are known to regulate neuronal firing, but their role in repetitive firing and learning in mammals is not well characterized. To determine the contribution of the auxiliary K⁺ channel subunit Kvβ1.1 to A-type K⁺ currents and to study the physiological role of A-type K⁺ channels in repetitive firing and learning, we deleted the Kvβ1.1 gene in mice. The loss of Kvβ1.1 resulted in a reduced K⁺ current inactivation in hippocampal CA1 pyramidal neurons. Furthermore, in the mutant neurons, frequency-dependent spike broadening and the slow afterhyperpolarization (sAHP) were reduced. This suggests that Kvβ1.1-dependent A-type K⁺ channels contribute to frequency-dependent spike broadening and may regulate the sAHP by controlling Ca²⁺ influx during action potentials. The Kvβ1.1-deficient mice showed normal synaptic plasticity but were impaired in the learning of a water maze test and in the social transmission of food preference task, indicating that the Kvβ1.1 subunit contributes to certain types of learning and memory.     

An artificial eye for evaluating videobased eye recording systems

Videobased corneal-reflection-to-pupil-center systems are widely used in eye movement research. In this paper, an artificial eye drawn on a computer screen is presented. The artificial eye provides a way to simulate measurements of eye position in human subjects. The method allows testing videobased systems on the level of the signal and on the level of the calibration algorithm used to map the eye position parameters to stimulus space. In addition, the artificial eye can be used to evaluate specific hypotheses concerning the functioning or malfunctioning of the eye recorder and as a help in developing data analysis programs.     

Shape equivalence under perspective and projective transformations

When a planar shape is viewed obliquely, it is deformed by a perspective deformation. If the visual system were to pick up geometrical invariants from such projections, these would necessarily be invariant under the wider class of projective transformations. To what extent can the visual system tell the difference between perspective and nonperspective but still projective deformations of shapes? To investigate this, observers were asked to indicate which of two test patterns most resembled a standard pattern. The test patterns were related to the standard pattern by a perspective or projective transformation, or they were completely unrelated. Performance was slightly better in a matching task with perspective and unrelated test patterns (92.6%) than in a projective-random matching task (88.8%). In a direct comparison, participants had a small preference (58.5%) for the perspectively related patterns over the projectively related ones. Preferences were based on the values of the transformation parameters (slant and shear). Hence, perspective and projective transformations yielded perceptual differences, but they were not treated in a categorically different manner by the human visual system.     

Situational Determinants of the Acceptability of Telling Lies1

It was tested whether the same factors people take into account when involved in the decision to lie apply to the evaluation of lies presented in scenarios. The scenarios represented 12 different situation categories formed by the crossing of the motive for lying (social. individualistic, egoistic), the relative importance of the situation (important matter, unimportant matter), and the closeness of the relation between the subject and the receiver of the lie (best friend, acquaintance). The acceptability of lying was evaluated from 2 perspectives (self, others) by 180 women of the general public. The results show that as the interest of the person that is lied to becomes greater, lying becomes more acceptable. As the interest of the liar becomes greater, lying becomes less acceptable. The systematically higher estimations of acceptability attributed to others indicate a false-uniqueness effect.     

Is pain-related fear a predictor of somatosensory hypervigilance in chronic low back pain patients?

Pain-related fear has been found to be associated with increased disability and increased pain perception in patients with chronic low back pain. A possible mechanism by which pain-related fear could lead to increased pain perception is heightened attention to somatosensory sensations. In the present study, chronic pain patients reporting either a high or low level of pain related fear and control participants performed an auditory reaction time task, while occasionally non-painful electrical stimuli--accompanied by threatening instructions--were given to the arm or back. In the primary task condition, participants had to perform the auditory task while ignoring the electrical stimuli. Next, the task was presented under dual task conditions in which participants had to respond both to tones as well as to detection of electrical stimuli. It was hypothesized that for the primary task, high fearful patients would show greater disruption of performance on the auditory task than low fearful patients and controls when stimuli were presented to the back. For the dual task, slower reaction times for the auditory task, in combination with faster detection of electrical stimuli was expected. The hypotheses were not confirmed but patients scoring high on pain-related fear did show an overall increase in reaction time for all conditions of the primary task, with or without simultaneous stimulation. Regression analyses demonstrated that high pain-related fear was associated with increased reaction time to tones both in patients and healthy controls, and that within patients pain-related fear was a better predictor of reaction time to tones than present pain intensity. The findings may be interpreted as showing that patients with elevated levels of pain-related fear habitually attend to somatic sensations, giving less priority to other attention-demanding tasks.     

Patient experiences with treatment in private practice compared with public mental health services

The study compared patient experiences with psychiatric treatment provided by private practitioners and public outpatient clinics. Questionnaires were completed by 642 outpatients in private practice and 6,677 outpatients in public clinics. The questionnaire included a measure of patient experiences comprising six items: treatment outcome, enough time for contact and dialogue with clinician, clinicians' understanding of patient's situation, suitability of therapy and treatment, clinician follow-up of planned actions, and influence on treatment. Patients in private practice had generally better experiences than patients in public outpatient treatment. The difference between private and public patients was largest for patients with poor self-evaluated mental health or those who had just one consultation in the previous three months. Private practitioners appear to have an important role in mental health services delivery, and patients have relatively good experiences with services. Further studies that assess the patient - clinician interaction in different mental health services may give further insights into potential service improvements.     

Clinical events in coronary patients who report low distress: adverse effect of repressive coping

OBJECTIVE: Coronary artery disease (CAD) patients who report low distress are considered to be at low psychological risk for clinical events. However, patients with a repressive coping style may fail to detect and report signals of emotional distress. The authors hypothesized that repressive CAD patients are at risk for clinical events, despite low self-rated distress. DESIGN: This was a prospective 5- to 10-year follow-up study, with a mean follow-up of 6.6 years. At baseline, 731 CAD patients filled out Trait-Anxiety (distress), Marlowe-Crowne (defensiveness), and Type D scales; 159 patients were classified as "repressive," 360 as "nonrepressive," and 212 as "Type D." MAIN OUTCOME MEASURES: The primary endpoint was a composite of total mortality or myocardial infarction (MI); the secondary endpoint was cardiac mortality/MI. RESULTS: No patients were lost to follow-up; 91 patients had a clinical event (including 35 cardiac death and 32 MI). Repressive patients reported low levels of anxiety, anger and depression at baseline, but were at increased risk for death/MI (21/159 = 13%) compared with nonrepressive patients (22/360 = 6%), p = .009. Poor systolic function, poor exercise tolerance, 3-vessel disease, index MI and Type-D personality--but not depression, anxiety or anger--also independently predicted clinical events. After controlling for these variables, repressive patients still had a twofold increased risk of death/MI, OR = 2.17, 95% CI = 1.10-4.08, p = .025). These findings were replicated for cardiac mortality/MI. CONCLUSION: CAD patients who use a repressive coping style are at increased risk for clinical events, despite their claims of low emotional distress. This phenomenon may cause an underestimation of the effect of stress on the heart. (PsycINFO Database Record (c) 2008 APA, all rights reserved).