The egocentric reference for visual exploration and orientation

Clinical signs of damage to the egocentric reference system range from the inability to detect stimuli in the real environment to a defect in recovering items from an internal representation. Despite clinical dissociations, current interpretations consider all symptoms as due to a single perturbation, differentially expressed according to the medium explored (perceptual or representational). We propose an alternative account based on the functional distinction between two separate egocentric mechanisms: one allowing construction of the immediate point of view, the other extracting a required perspective within a mental representation. Support to this claim comes from recent results in the domain of navigation, showing that separate cognitive mechanisms maintain the egocentric reference when actively exploring the visual space as opposed to moving according to an internal map. These mechanisms likely follow separate developmental pathways, seemingly depend on distinct neural pathways and are used independently by healthy adults, reflecting task demands and individual cognitive style. Implications for spatial cognition and social skills are discussed.     

The phantom illumination illusion

A novel brightness illusion in planar patterns is reported. The illusion occurs, for example, when surfaces with a luminance ramp shaded from black to white are positioned on a black homogeneous background, so that each white end of the surfaces faces a single point of the plane of the pattern. The illusion consists of the enhancement of the brightness of the background in a relatively wide area around the white ends of the surfaces. A parametric study was conducted in which participants were asked to rate the difference in brightness between the parts of the background inside and outside a virtual circle formed by disks with different luminance ramps. The results show that mean ratings of brightness depended on the luminance of the background, the luminance range of ramps, and the kind of ramp. Discussion of these results with reference to other brightness illusions (assimilation, neon color spreading, anomalous surfaces, visual phantoms, grating induction, and the glare effect) shows that t hephantom illumination illusion derives from processes producing the perception of ambient illumination.     

De Finetti coherence and the product law for independent events

Synthese - In an earlier paper the present author proved that de Finetti coherence is preserved under taking products of coherent books on two finite sets of independent events. Conversely, in this...     

A Critique of Victoria S. Harrison’s Internal Realist Approach to Pluralism

Philosophia - Victoria S. Harrison’s theory of internal pluralism approaches religious beliefs in terms of conceptual schemes. To her, this approach has the advantage of preserving core...     

The impact of phantom decoys on choices in cats

Context-dependent choice is an important aspect of decision making. The paper examines context-dependent choice in cats (Felis catus), with particular reference to the effect of local context, on the basis of hypotheses developed in the field of human decision making. Cats were initially confronted with two different feeding options. This binary choice set was later manipulated incorporating a decoy that was better than the available options but ultimately unavailable (a phantom). By means of a within-subjects manipulation of phantom location in the attribute space, the author compared the effects of close and distant phantoms on the final choices. The main finding is that close phantom decoys affected choice behavior of cats by altering the overall share of the available options, leading some animals to reject even some of the available feeding options, and by causing the animals to favor the available option that was more similar to the phantom decoy. No significant effects emerged for phantoms that were far from the alternatives in the attribute space. The strengths of this paper lie in its novel approach and high originality. No other study has used dominating decoys with animals or decoys that are unattainable. This paper provides strong links to the human decision making literature, the presentation of the predictions of a range of different choice models, and the novelty of the application to animals. The use of a phantom decoy is particularly interesting because the phantom cannot actually be chosen, and thus the binary and trinary choice sets both have the very same choices available. Overall, the effect of phantoms is real, interesting and new.     

The role of consumer ethical beliefs in product‐harm crises

The purpose of this paper is to investigate the consumer reaction during a product‐harm crisis by examining the interdependencies that exist among their ethical beliefs as consumers, their attributions of blame, their feelings of anger and finally their purchase intentions towards the affected company. To test the five research hypotheses, a questionnaire containing a hypothetical crisis scenario of a fictitious company was distributed to 277 consumers. Respondents were asked to read the scenario and answer questions regarding their attribution of responsibility to the company, their feelings of anger and their purchase intentions. In order to investigate consumers' ethical beliefs, a Consumer Ethics Scale was also included in the questionnaire. Structural equation modelling revealed a significant, positive correlation between attributions of blame, anger and ethical beliefs. Moreover, anger negatively affects purchase intentions, whereas the attribution of blame was not found to be significantly connected to purchase intentions. In spite of the rational connection between ethics and crisis, there is lack of research correlating these two concepts. Based on this gap in the literature, the current research attempts to connect ethical beliefs with consumer reactions and emotions during product‐harm crises. Copyright © 2011 John Wiley & Sons, Ltd.     

Value-based accounts of normative powers and the wishful thinking objection

Philosophical Studies - Normative powers like promising allow agents to effect changes to their reasons, permissions and rights by the means of communicative actions whose function is to effect...     

Characteristics and reversibility of dementia in Normal Pressure Hydrocephalus

Studies of the cognitive outcome after shunt insertion for treatment of Normal Pressure Hydrocephalus have reported widely mixed results. We prospectively studied performance of 60 patients with Normal Pressure Hydrocephalus on a comprehensive battery of neuropsychological tests before and after shunt surgery to determine which cognitive functions improve with shunt insertion. We also administered a subset of cognitive tests before and after temporary controlled drainage of cerebrospinal fluid to determine if change on this brief subset of tests after drainage could predict which patients would show cognitive improvement three to six months after shunt insertion. There was a significant improvement in learning, retention, and delayed recall of verbal memory three to six months after surgery (using paired t-tests). The majority (74%) of patients showed significant improvement (by at least one standard deviation) on at least one of the memory tests. Absence of improvement on verbal memory after temporary drainage of cerebrospinal fluid had a high negative predictive value for improvement on memory tests at 3-6 months after surgery (96%; p=0.0005). Also, the magnitude of improvement from Baseline to Post-Drainage on few specific tests of learning and recall significantly predicted the magnitude of improvement after shunt surgery on the same tests (r2=0.32-0.58; p=0.04-0.001). Results indicate that testing before and after temporary drainage may be useful in predicting which patients are less likely to improve in memory with shunting.