Aging and the depth of binocular rivalry suppression

Two experiments were designed to examine the effect of aging on the strength of binocular rivalry suppression. To produce rivalry, orthogonally oriented sine-wave luminance gratings were presented dichoptically. The observers were then required either to discriminate the spatial location of a probe spot presented to the dominant or suppressed eye's view or to detect the presence or absence of the probe. The observers in the younger and older age groups exhibited typical rivalry suppression for both tasks (i.e., the probe was more difficult to detect or discriminate when presented to the suppressed eye), but the magnitude of the suppression was significantly larger in the older observers. This increased suppression that accompanies aging can be explained by a reduction in the inhibition produced by the binocular matching circuitry of S. R. Lehky and R. Blake's (1991) model.     

Taxometric and factor analytic models of anxiety sensitivity: integrating approaches to latent structural research

This study represents an effort to better understand the latent structure of anxiety sensitivity (AS), as indexed by the 16-item Anxiety Sensitivity Index (ASI; S. Reiss, R. A. Peterson, M. Gursky, & R. J. McNally, 1986), by using taxometric and factor-analytic approaches in an integrative manner. Taxometric analyses indicated that AS has a taxonic latent class structure (i.e., a dichotomous latent class structure) in a large sample of North American adults (N=2,515). As predicted, confirmatory factor analyses indicated that a multidimensional 3-factor model of AS provided a good fit for the AS complement class (normative or low-risk form) but not the AS taxon class (high-risk form). Exploratory factor analytic results suggested that the AS taxon may demonstrate a unique, unidimensional factor solution, though there are alternative indications that it may be characterized by a 2-factor solution. Findings suggest that the latent structural nature of AS can be conceptualized as a taxonic latent class structure composed of 2 types or forms of AS, each of these forms characterized by its own unique latent continuity and dimensional structure.     

The Kitty Genovese murder and the social psychology of helping: the parable of the 38 witnesses

This article argues that an iconic event in the history of helping research -- the story of the 38 witnesses who remained inactive during the murder of Kitty Genovese -- is not supported by the available evidence. Using archive material, the authors show that there is no evidence for the presence of 38 witnesses, or that witnesses observed the murder, or that witnesses remained inactive. Drawing a distinction between the robust bystander research tradition and the story of the 38 witnesses, the authors explore the consequences of the story for the discipline of psychology. They argue that the story itself plays a key role in psychology textbooks. They also suggest that the story marks a new way of conceptualizing the dangers of immersion in social groups. Finally, they suggest that the story itself has become a modern parable, the telling of which has served to limit the scope of inquiry into emergency helping.     

Multidimensional modeling with unidimensional approximations

This paper advances nonparametric multidimensional item response theory by reporting experimental results on the use of nonmetric multidimensional scaling (MDS) to synthesize a multidimensional model from several approximating one-dimensional models. A two-dimensional simulation data set contains items in which the two-component traits combine linearly (dominance model items) and items in which the two-component traits combine quadratically (ideal point items). Several unidimensional approximations of the two-dimensional model were obtained by running unidimensional estimation software on the simulated data set. The graphs reconstructed from MDS of the unidimensional approximations at selected points clearly separate dominance items from ideal point items, and also various types of dominance or ideal point models. MDS also succeeded in determining the dimensionality of the simulation model items from the observable item responses.     

Gradations of awareness in a modified sequence learning task

We argue performance in the serial reaction time (SRT) task is associated with gradations of awareness that provide examples of fringe consciousness [Mangan, B. (1993b). Taking phenomenology seriously: the “fringe” and its implications for cognitive research. Consciousness and Cognition, 2, 89–108, Mangan, B. (2003). The conscious “fringe”: Bringing William James up to date. In B. J. Baars, W. P. Banks & J. B. Newman (Eds.), Essential sources in the scientific study of consciousness (pp. 741–759). Cambridge, MA: The MIT Press.], and address limitations of the traditional SRT procedure, including criticism of exclusion generation tasks. Two experiments are conducted with a modified SRT procedure where irrelevant stimulus attributes obscure the sequence rule. Our modified paradigm, which includes a novel exclusion task, makes it easier to demonstrate a previously controversial influence of response stimulus interval (RSI) on awareness. It also allows identification of participants showing fringe consciousness rather than explicit sequence knowledge, as reflected by dissociations between different awareness measures. The NEO-PI-R variable Openness to Feelings influenced the diversity of subjective feelings reported during two awareness measures, but not the degree of learning and awareness as previously found with traditional SRT tasks [Norman, E., Price, M. C., & Duff, S. C. (2006). Fringe consciousness in sequence learning: the influence of individual differences. Consciousness and Cognition, 15(4), 723–760.]. This suggests possible distinctions between two components of fringe consciousness.     

Psychological correlates of PTSD symptoms following stroke

This study assessed associations between a number of demographic, medical and psychological risk factors and post-traumatic stress disorder (PTSD) symptoms following stroke. Individuals (N = 102) who had experienced a stroke within the previous year participated in the study. Participants completed questionnaires containing measures of PTSD symptoms and a range of psychological risk factors (i.e., anxiety, depression, negative affect, dissociation, cognitive appraisals). Regression analyses revealed the variables under consideration were able to explain large proportions of the variance in the number (R(2) = .54, p < 0.001) and severity (R(2) = .58, p < 0.001) of PTSD symptoms. Number of strokes, negative affect and cognitive appraisals emerged as significant predictors of both the number and severity of PTSD symptoms. The present findings suggest that a significant proportion of stroke patients may benefit from the detection and treatment of PTSD symptoms.     

How to Measure and Explain Achievement Change in Large-Scale Assessments: A Rejoinder

In this rejoinder, we discuss substantive and methodological validity issues of large-scale assessments of trends in student achievement, commenting on the discussion paper by Van den Heuvel-Panhuizen, Robitzsch, Treffers, and Köller (2009). We focus on methodological challenges in deciding what to measure, how to measure it, and how to foster stability. Next, we discuss what to do with trends that are found. Finally, we reflect on how the research findings were received.