The Evolution of a Scientific Concept

A philosophically comprehended account is given of the genesis and evolution of the concept of protein. Characteristic of this development were not shifts in theory in response to new experimental data, but shifts in the range of questions that the available experimental resources were fit to cope with effectively. Apart from explanatory success with regard to its own range of questions, various other selecting factors acted on a conceptual variant, some stemming from a competing set of research questions, others from an altogether different field of inquiry, and still others from the external environment. These results are best explained on, hence support, an evolutionary model of the progress of experimental investigation, whose outlines are briefly discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

The conscious experience of color constancy and neural responses to subliminal deviations – A behavioral and EEG/ERP oddball study

IntroductionColor constancy, a property of conscious color experience, maintains object color appearance across illuminant changes. We investigated the neural correlates of subliminal vs. conscious stimulus deviations of color constancy manipulations.MethodsBehavioral and Oddball EEG/ERP experiments were conducted (n = 20). Psychophysical illuminant variation discrimination thresholds were first estimated, to establish individual perceptual awareness ranges, allowing for simulation of natural daylight spectral and spatial variations on colored surfaces, at different ambiguity levels.ResultsBehavioral results validated illuminant choice. ERPs showed a significant modulation of posterior P1 component specifically for the subliminal global uniform deviation condition, respecting color constancy. Neural correlates of conscious percepts were identified at posterior N2-P3 latencies, parietal (P3b) and frontal regions.ConclusionsWe identified an early subliminal correlate of low-level illuminant change, which reflects automatic unconscious detection of global color constancy deviations. Its suppression under conscious perception is probably due to top-down suppression according to prediction error models.     

The Contribution of Attention to the Right Visual Field Advantage for Word Recognition

Perceptual asymmetries have been explained by structural, attentional bias and attentional advantage models. Structural models focus on asymmetries in the physical access information has to the hemispheres, whereas attentional models focus on asymmetries in the operation of attentional processes. A series of experiments was conducted to assess the contribution of attentional mechanisms to the right visual field (RVF) advantage found for word recognition. Valid, invalid and neutral peripheral cues were presented at a variety of stimulus onset asynchronies to manipulate spatial attention. Results indicated a significant RVF advantage and cueing effect. The effect of the cue was stronger for the left visual field than the RVF. This interaction supports the attentional advantage model which suggests that the left hemisphere requires less attention to process words. The attentional asymmetry is interpreted in terms of the different word processing styles used by the left and right hemispheres. These results have ramifications for the methodology used in divided visual field research and the interpretation of this research.     

An application of visual interactive goal programming: a case in vendor selection decisions

This article presents the vendor selection problem of the hydraulic pump division of a US original equipment manufacturing company. The division wants to identify appropriate vendors and allocate purchase orders among them while minimizing product acquisition costs and maximizing total product quality and delivery reliability. Visual interactive goal programming is used as a multi‐criteria decision analysis tool. Interaction with decision makers during the model building and solution process, and implications are discussed. Copyright © 1999 John Wiley & Sons, Ltd.