N2 - A group of three pigeons was trained on a 4‐ply multiple schedule: a green color and a vertical line superimposed upon an achromatic background as positive stimuli, and a red color and a horizontal line on an achromatic background as negative stimuli. The pigeons were tested with the vertical line superimposed upon different achromatic background intensities, then with the vertical line superimposed upon different green background intensities, and finally with the vertical line and its training achromatic background attenuated (and unattenuated) by a neutral density filter. The gradients peaked at the luminance of the achromatic background used during training and at the equivalent luminance for the green background when it was substituted for the achromatic background. The brightness contrast, not the background luminance, was the critical variable as the neutral density filter attenuated both the line and the background equally, leaving brightness contrast unchanged; there was no response decrement to this attenuated stimulus. Two other groups of three pigeons showed that they attended to line orientation as well as to brightness contrast. The brightness contrast hypothesis was extended to explain results of attention experiments and combined cue experiments which have used line stimuli in combinations with different backgrounds. 1980 Society for the Experimental Analysis of Behavior
N2 - A recent perceptual imaging experiment uses a rare 2 x 2 design to dissociate selective visual attention from visual consciousness. Its conclusions support the hypothesis that visual consciousness does not arise from neurons in primary visual cortex and forces a reinterpretation of numerous prior studies.
Controversial new theory of dark matter could ..
It is not generally appreciated that the p value, as conceived by R. A. Fisher, is not compatible with the Neyman-Pearson hypothesis test in which it has become embedded. The p value was meant to be a flexible inferential measure, whereas the hypothesis test was a rule for behavior, not inference. The combination of the two methods has led to a reinterpretation of the p value simultaneously as an "observed error rate" and as a measure of evidence. Both of these interpretations are problematic, and their combination has obscured the important differences between Neyman and Fisher on the nature of the scientific method and inhibited our understanding of the philosophic implications of the basic methods in use today. An analysis using another method promoted by Fisher, mathematical likelihood, shows that the p value substantially overstates the evidence against the null hypothesis. Likelihood makes clearer the distinction between error rates and inferential evidence and is a quantitative tool for expressing evidential strength that is more appropriate for the purposes of epidemiology than the p value.
Low Involvement Versus High Involvement Cognitive Structures
The Samuelson hypothesis implies that the volatility of futures price changes increases as a contract's delivery date nears. In markets where the Samuelson hypothesis holds, accurate valuation of futures-related derivatives requires that a term structure of futures volatilities be estimated. We develop a framework for predicting the markets where the Samuelson hypothesis should be expected to hold. Unlike a prominent reinterpretation of the hypothesis, our work shows that clustering of information flows near the delivery date is not a necessary condition. We show instead that the hypothesis is generally supported in markets where spot price changes include a predictable temporary component; we argue that this condition is much more likely to be met in markets for real assets than for financial assets. Finally, we provide empirical evidence consistent with our predictions.
Pluralism, Religious | Internet Encyclopedia of Philosophy
AB - A recent perceptual imaging experiment uses a rare 2 x 2 design to dissociate selective visual attention from visual consciousness. Its conclusions support the hypothesis that visual consciousness does not arise from neurons in primary visual cortex and forces a reinterpretation of numerous prior studies.