Orientation-specific luminance aftereffects

Prolonged viewing of bright vertical (horizontal) gratings alternating with dim horizontal (vertical) gratings generates negative brightness aftereffects that are contingent on the orientation of orthogonal test gratings. The effect is measured by a brightness cancellation technique, similar to the color cancellation technique used in measuring McCollough effects. Like the latter, brightness aftereffects appear to persist for long periods. The magnitude of these aftereffects is a positive monotonic function of the luminance difference between the inducing gratings, and it depends on the conditions of induction; monocular induction generates larger aftereffects than binocular induction does. The aftereffect transfers interocularly, although its magnitude in the contralateral eye is substantially attenuated; binocular measurement, following monocular induction, results in even smaller aftereffects. An attempt to understand these findings within the computational model of brightness perception developed by Grossberg and Mingolla (1985a, 1985b) is presented.     

Are fear-avoidance beliefs related to the inception of an episode of back pain? A prospective study

Abstract Fear-avoidance beliefs and catastrophizing have been implicated in chronic pain and theoretical models have been developed that feature these factor in the transition from acute to chronic pain. However, little has been done to determine whether these factors occur in the general population or whether they arc associated with the inception of an episode of neck or back pain. The aim of this study was to evaluate prospectively the effects of fear-avoidance beliefs and catastrophizing on the development of an episode of self-reported pain and associated physical functioning. To achieve this, we selected a sample of 415 people from the general population who reported no spinal pain during the past year. At the pretest a battery of questionnaires was administered to assess beliefs about pain and activity and it featured the Pain Catastrophizing Scale and a modified version of the Fear-Avoidance Beliefs Questionnaire. One year later outcome was evaluated by self-reports of the occurrence of a pain episode as well as a self-administered physical function test. The results showed that scores on both fear-avoidme and cabstrophizing were quite low. During the one year follow-up, 19% of the sample suffered an episode of back pain. Those with scores above the median on fear-avoidance beliefs at the pretest had twice the risk of suffering an episode of back pain and a 1.7 times higher risk of lowered physical function at the follow-up. Catastrophizing was somewhat less salient, increasing the risk of pain or lowered function by 1.5. but with confidence intervals falling below unity. These data indicate that fear-avoidance beliefs may be involved at a very early pint in the development of pain and associated activity problems in people with back pain. Theoretically. our results support the idea that fear-avoidance beliefs may develop in an interaction with the experience of pain. Clinically, the results suggest that catastrophizing and particularly fear-avoidance beliefs are important in the development of a pain problem and might be of use in screening procedures.     

Relativism and Faultless Disagreement

The argument from faultless disagreement employed by the relativist purports to show that contextualism falls short of explaining cases of faultless disagreement. The demonstration is intended to give credence to the relativist semantics of epistemic modality expressions. In this paper we present some cases showing that even though cases of faultless disagreement do reveal some intrinsic features of epistemic modality claims, they do not support the relativist semantics. The sophistication of faultless disagreement goes beyond what the relativist semantics can cope with. We also advance an epistemologically oriented proposal to account for faultless disagreement.     

Reducing the threat value of chronic pain: A preliminary replicated single-case study of interoceptive exposure versus distraction in six individuals with chronic back pain

This paper describes a preliminary experimental evaluation of a technique intended to help people suffering from chronic back pain and low pain acceptance to alter the aversiveness or threat value of their persisting pain. Using a multiple baseline cross-over design six individuals with chronic back pain were taught to use a form of interoceptive exposure as well as a relaxation/distraction breathing-based technique in the presence of their pain. Half the participants used one method for three weeks, and then crossed over to the other method for a further three weeks. The other half did the reverse. Assessments were conducted at pre/post treatment and at a three month follow-up. Daily monitoring of pain-related distress was also completed. The results indicated moderately high improvements in pain acceptance across most participants and corresponding declines in pain-related distress. No clear differences occurred between conditions, but the changes on disability and catastrophising scales for most cases were consistent with those reported after more substantial interventions. The study raises some important clinical and methodological issues that could inform future research in this area.     

Comparative syllogism and counterfactual knowledge

Comparative syllogism is a type of scientific reasoning widely used, explicitly or implicitly, for inferences from observations to conclusions about effectiveness, but its philosophical significance has not been fully elaborated or appreciated. In its simplest form, the comparative syllogism derives a conclusion about the effectiveness of a factor (e.g. a treatment or an exposure) on a certain property via an experiment design using a test (experimental) group and a comparison (control) group. Our objective is to show that the comparative syllogism can be understood as encoding a simulation view of counterfactuals, in that counterfactual situations are conceptual constructs that can be correctly simulated by homogeneous comparison groups. In this simulation view, the empirical data from the comparison groups play an evidential role in the evaluation of counterfactuals and in obtaining counterfactual knowledge. We further indicate how successful experimental designs can help us to obtain correct simulations, and thus to bring us to scientifically-empirically based counterfactual knowledge.     

2020 Foresight: Practicing Ethically While Doing Things That Don’t Yet Exist

The APA Ethical Code struggles to offer guidance in the rapidly changing field of clinical health psychology. Professional challenges anticipated in the next decade are described, and their implications for ethical practice examined. This paper is based in part on a presentation at the 2009 Conference at the Association of Psychologists in Academic Health Centers held in St. Louis, Missouri.