The Causal Theory of Perception Revisited

It is generally agreed upon that Grice’s causal theory of perception describes a necessary condition for perception. It does not describe sufficient conditions, however, since there are entities in causal chains that we do not perceive and not all causal chains yield perceptions. One strategy for overcoming these problems is that of strengthening the notion of causality (as done by David Lewis). Another is that of specifying the criteria according to which perceptual experiences should match the way the world is (Frank Jackson and Michael Tye). Finally, one can also try to provide sufficient conditions by elaborating on the content of perceptual experiences (Alva N?e). These different strategies are considered in this paper, with the conclusion that none of them is successful. However, a careful examination of their problems points towards the general solution that we outline at the end.

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Degrees of Causation

The primary aim of this paper is to analyze the concept of degrees of causal contribution for actual events and examine the way in which it can be formally defined. This should go some way to filling out a gap in the legal and philosophical literature on causation. By adopting the conception of a cause as a necessary element of a sufficient set (the so-called NESS test) we show that the concept of degrees of causation can be given clear and even empirical meaning. We then apply a game theoretical framework to derive a measure of causal contribution. Our favoured measure turns out to be a generalised version of the normalized Penrose–Banzhaf index of voting power.     

The Mental Model Theory of Conditionals: A Reply to Guy Politzer

This paper replies to Politzer’s (2007) criticisms of the mental model theory of conditionals. It argues that the theory provides a correct account of negation of conditionals, that it does not provide a truth-functional account of their meaning, though it predicts that certain interpretations of conditionals yield acceptable versions of the ‘paradoxes’ of material implication, and that it postulates three main strategies for estimating the probabilities of conditionals.     

Anomalous brain dominance and the immune system: Do left-handers have specific immunological patterns?

Geschwind and Behan (1982) and Geschwind and Galaburda (1985a, 1985b, 1985c) suggested a correlation between brain laterality and immune disorders. To test whether this hypothesis holds true not only for the frequency of immune diseases and circulating autoantibodies, but extends also to cellular immunity, we examined the association between handedness and markers of cellular immunity. Twenty-seven left-handed and 37 right-handed subjects were serologically screened for cellular parameters and 22 left-handed subjects were typed for human leukocyte antigen (HLA). When compared to the right-handers, the left-handed group showed a significant decrease in the inflammatory cell types CD3(+) T cells (total T cells), CD4(+) T cells (T-helper cells), and HLA-Dr (MHC-II, antigen-presenting cells) as well as in the CD19(+) cells (B cells) and CD16/CD57(+) cells (natural killer cells). We assume a relationship exists between cerebral hemispheric specialisation and the immune system not only for humoral but also for cellular immunity, and we discuss the role of the major histocompatibility complex in neurological and immunological development.     

Biological and environmental initial conditions shape the trajectories of cognitive and social‐emotional development across the first years of life

Human development is thought to evolve from the dynamic interchange of biological dispositions and environmental provisions; yet the effects of specific biological and environmental birth conditions on the trajectories of cognitive and social‐emotional growth have rarely been studied. We observed 126 children at six time‐points from birth to 5 years. Intelligence, maternal sensitivity, and child social engagement were repeatedly tested. Effects of neonatal vagal tone (VT) and maternal postpartum depressive symptoms on growth‐rates were assessed. Cognitive development showed a substantial growth‐spurt between 2 and 5 years and social engagement increased rapidly across the first year and more gradually thereafter. VT improved cognitive and social‐emotional growth‐rates across the first year, whereas maternal depressive symptoms interfered with growth from 2 to 5 years. Differences between infants with none, one, or two non‐optimal birth conditions increased with age. Findings shed light on the dynamics of early development as it is shaped by biological and environmental initial conditions.     

Percentage of nonoverlapping corrected data

In the present study, we proposed a modification in one of the most frequently applied effect-size procedures in single-case data analysis: the percentage of nonoverlapping data. In contrast with other techniques, the calculus and interpretation of this procedure are straightforward and can be easily complemented by visual inspection of the graphed data. Although the percentage of nonoverlapping data has been found to perform reasonably well in N = 1 data, the magnitude of effect estimates that it yields can be distorted by trend and autocorrelation. Therefore, the data-correction procedure focuses on removing the baseline trend from data prior to estimating the change produced in the behavior as a result of intervention. A simulation study was carried out in order to compare the original and the modified procedures in several experimental conditions. The results suggest that the new proposal is unaffected by trend and autocorrelation and that it can be used in case of unstable baselines and sequentially related measurements.     

TwoMP: A MATLAB graphical user interface for two-mode partitioning

Two-way two-mode data occur in almost every domain of scientific psychology. The information present in such data, however, may be hard to grasp because of the dimensions of one or both modes. Two-mode partitioning addresses this problem by breaking down both modes into a number of mutually exclusive and exhaustive subsets. Although such a technique may be very useful, up to now, software—and consequently, two-mode partitioning—has been available only to a handful of specialists in the field. In this article, we present a free, easy-to-use MATLAB graphical user interface (TwoMP) for two-mode partitioning models, specifically developed for nonspecialist users. A short formal introduction is given on the statistics of the method, and the basic use of TwoMP is demonstrated with an example.     

A standardized set of 260 pictures for Modern Greek: Norms for name agreement, age of acquisition, and visual complexity

The appropriate selection of both pictorial and linguistic experimental stimuli requires a previous languagespecific standardization process of the materials across different variables. Considering that such normative data have not yet been collected for Modern Greek, in this study normative data for the color version of the Snodgrass and Vanderwart picture set (Rossion & Pourtois, 2004) were collected from 330 native Greek adults. Participants named the pictures (providing name agreement ratings) and rated them for visual complexity and age of acquisition. The obtained measures represent a useful tool for further research on Greek language processing and constitute the first picture normative study for this language. The picture norms from this study and previous ones may be downloaded from brm.psychonomic-journals.org/content/supplemental.     

Randomization tests for multiple-baseline designs: An extension of the SCRT-R package

Multiple-baseline designs are an extension of the basic single-case AB phase designs, in which several of those AB designs are implemented simultaneously to different persons, behaviors, or settings, and the intervention is introduced in a staggered way to the different units. These designs are well-suited for research in the behavioral sciences. We discuss the advantages and limitations for valid inferences, and suggest a statistical technique—randomization tests—for use with multiple-baseline data, to complement visual analysis. In addition, we provide an extension of our SCRT-R package (which already contained means for conducting randomization tests on single-case phase and alternation designs), for multiple-baseline AB data.