COLOR THRESHOLD MEASUREMENTS IN SCOTOPIC VISION

The absolute and the color threshold in scotopic vision generally coincide during dark adaptation, indicating that color-threshold intensity is a measure of the concentration of rhodopsin, and that different modes of rhodopsin regeneration are reflected in the measurements of the color threshold.     

COLOR THRESHOLD MEASUREMENTS IN SCOTOPIC VISION: Test-stimulation varied

S tabell , U. & S tabell , B. Color threshold measurements in scotopic vision. II. Test-stimulation varied. Scand. J. Psychol ., 1968, 9, 129–132.—The color threshold curve generally coincides with the dark adaptation curve of the rods, irrespectively of test-stimulation variation, confirming the assumption that a threshold response of rods may initiate a color-related process. Variation of color threshold intensity is thus assumed to reflect variation of rod threshold intensity.     

RODS AS COLOR RECEPTORS IN SCOTOPIC VISION

With the method of successive contrast, all the principal colors have been observed when test-stimulating at levels of intensity within the photochromatic interval. Using the method of simultaneous contrast, blue and green colors have been observed within this area of intensity. It is concluded that rod activity must somehow initiate these color processes.     

RODS AS COLOR RECEPTORS IN PHOTOPIC VISION

Comparing a foveal and an extra-foveal field during dark adaptation, transition from chromatic to achromatic vision at intensity levels above the cone plateau started around the break of the dark adaptation curve. Pre-stimulating the two fields in a dark-adapted state with deep red, and test-stimulating when returning sensitivity had reached absolute threshold of the dark-adapted eye, with green filters at intensities above the specific threshold, the fields matched as to hue and saturation. It appears that rod and cone activities are integrated and function as a synchronized unit during the initial recovery phase of dark adaptation.     

TRANSITION FROM ROD TO CONE VISION I. Simultaneous contrast

S tabell , B. Transition from rod to cone vision. I. Simultaneous contrast. Scand. J. Psychol ., 1969, 10 , 61–64.—Above the specific threshold, color quality depended on the test filter, while at lower intensities the same color was observed irrespectively of the test filter used, confirming the assumption that colors within the photochromatic interval are triggered by rod activity. The lawful relation between rise of specific threshold and increase of rod sensitivity was not found under the condition of simultaneous contrast.     

TRANSITION FROM ROD TO CONE VISION: II. Successive contrast

S tabell , B. & S tabell , U. Transition from rod to cone vision. II. Successive contrast. Scad J. Psychol., 1969, 10 137–139—Transition from chromatic rod to chromatic cone activity during dark adaptation is interpreted as a kind of color mixing.     

TRANSITION FROM ROD TO CONE VISION:III. Successive contrast anew

S tabell , U. & S tabell , B. Transition from rod to cone vision. III. Successive contrast anew. Scand. J. Psychol ., 1969, 10 , 140–144—The relation between the specific threshold level and the upper limit of the scotopic contrast color was investigated. The achromatic interval between the scotopic and the photopic component increased when time in darkness increased, and when pre-stimulation was reduced as regards intensity, duration, or cone/rod ratio. The results are interpreted on the basis of the opponent theory of color vision.     

PSYCHOPHYSICAL INVARIANTS OF ACHROMATIC COLOUR VISION: IV. Depth adjacency and simultaneous contrast

L ie , I. Psychophysical invariants of achromatic colour vision. IV. Depth adjacency and simultaneous contrast. Scand. J. Psychol ., 1969, 10 , 282–286.— Achromatic colour contrast as a function of adjacent subareas was investigated by a stereoscopic depth technique. The degree of colour contrast was found to be independent of stereoscopic depth.     

Simultaneous contrast: evidence from licking microstructure and cross-solution comparisons

The microstructure of rats' licking responses was analyzed to investigate both "classic" simultaneous contrast (e.g., Flaherty & Largen, 1975) and a novel discrete-trial contrast procedure where access to an 8% test solution of sucrose was preceded by a sample of either 2%, 8%, or 32% sucrose (Experiments 1 and 2, respectively). Consumption of a given concentration of sucrose was higher when consumed alongside a low rather than high concentration comparison solution (positive contrast) and consumption of a given concentration of sucrose was lower when consumed alongside a high rather than a low concentration comparison solution (negative contrast). Furthermore, positive contrast increased the size of lick clusters while negative contrast decreased the size of lick clusters. Lick cluster size has a positive monotonic relationship with the concentration of palatable solutions and so positive and negative contrasts produced changes in lick cluster size that were analogous to raising or lowering the concentration of the test solution respectively. Experiment 3 utilized the discrete-trial procedure and compared contrast between two solutions of the same type (sucrose-sucrose or maltodextrin-maltodextrin) or contrast across solutions (sucrose-maltodextrin or maltodextrin-sucrose). Contrast effects on consumption were present, but reduced in size, in the cross-solution conditions. Moreover, lick cluster sizes were not affected at all by cross-solution contrasts as they were by same-solution contrasts. These results are consistent with the idea that simultaneous contrast effects depend, at least partially, on sensory mechanisms.     

Saliency on a natural scene background: Effects of color and luminance contrast add linearly

In natural vision, shifts in spatial attention are associated with shifts of gaze. Computational models of such overt attention typically use the concept of a saliency map: Normalized maps of center-surround differences are computed for individual stimulus features and added linearly to obtain the saliency map. Although the predictions of such models correlate with fixated locations better than chance, their mechanistic assumptions are less well investigated. Here, we tested one key assumption: Do the effects of different features add linearly or according to a max-type of interaction? We measured the eye position of observers viewing natural stimuli whose luminance contrast and/or color contrast (saturation) increased gradually toward one side. We found that these feature gradients biased fixations toward regions of high contrasts. When two contrast gradients (color and luminance) were superimposed, linear summation of their individual effects predicted their combined effect. This demonstrated that the interaction of color and luminance contrast with respect to human overt attention is—irrespective of the precise model—consistent with the assumption of linearity, but not with a max-type interaction of these features.     

THE FRUITS OF PLURALISM: A VISION FOR THE NEXT SEVEN YEARS IN RELIGION/SCIENCE

This article offers a vision for work at the intersection of science and religion over the coming seven years. Because predictions are inherently risky and are more often than not false, the text first offers an assessment of the current state of the science‐religion discussion and a quick survey of the last 50 years of work in this field. The implications of the six features of this vision for the future of the field are then presented in some detail. Rather than bemoaning the current diversity of approaches and conclusions as a negative result, I endorse it as a healthy sign—if acknowledged honestly and managed well.     

额叶在启动效应中的作用机制：对额叶损伤病人颜色命名和词命名任务的分析

以额叶损伤病人为被试,探讨在知觉型联想启动和知觉启动中,额叶的作用及其内在机制。实验任务包括颜色命名和词命名任务,以及相应的再认任务。结果表明,额叶损伤病人在颜色命名和词命名任务中,对旧词和重组颜色词的命名时间都没有明显差别,联想启动和颜色启动效应受损,但轻度记忆损伤病人与正常对照组之间的再认成绩相似。相关分析发现联想启动和颜色启动与额叶的多项功能有中度相关。这表明,额叶参与了知觉型联想启动效应和知觉启动,并且与其抑制和注意等执行功能有关。     

REESTABLISHING “THE SOCIAL” IN RESEARCH ON DEMOCRATIC PROCESSES: MID‐CENTURY VOTER STUDIES AND PAUL F. LAZARSFELD'S ALTERNATIVE VISION

Voter studies conducted in the United States during the first decades after World War II transformed social scientific research on democracy. Especially important were the rapid innovations in survey research methods developed by two prominent research centers at Columbia University and the University of Michigan. This article argues that the Columbia and Michigan voter studies presented two visions for research on democracy. Where the Michigan research produced quantitative measures expressing the ‘political behavior’ of the electorate, the Columbia studies, and especially Paul F. Lazarsfeld, presented an alternative vision for qualitative research on political choice. Largely ignored by later voter studies, this vision prefigured much contemporary research on democracy that embraces a qualitative or interpretive approach. This article reconstructs Lazarsfeld's alternative vision, describes the institutional context in which scholars disregarded it in favor of formal quantitative models, and argues for its recognition as a forerunner to qualitative research on democratic processes.