Surajit Nundy

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The relationship between luminance (i.e., the photometric intensity of light) and its perception (i.e., sensations of lightness or brightness) has long been a puzzle. In addition to the mystery of why these perceptual qualities do not scale with luminance in any simple way, "illusions" such as simultaneous brightness contrast, Mach bands,(More)
Although it has long been apparent that observers tend to overestimate the magnitude of acute angles and underestimate obtuse ones, there is no consensus about why such distortions are seen. Geometrical modeling combined with psychophysical testing of human subjects indicates that these misperceptions are the result of an empirical strategy that resolves(More)
The perceptions of lightness or brightness elicited by a visual target are linked to its luminance by a nonlinear function that varies according to the physical characteristics of the target and the background on which it is presented. Although no generally accepted explanation of this scaling relationship exists, it has long been considered a byproduct of(More)
Recent work on brightness, color, and form has suggested that human visual percepts represent the probable sources of retinal images rather than stimulus features as such. Here we investigate the plausibility of this empirical concept of vision by allowing autonomous agents to evolve in virtual environments based solely on the relative success of their(More)
Hepatic venous outflow obstruction (HVOO) is a rare cause of portal hypertension and conservative treatment is usually ineffective. A large series of patients gave us an opportunity to devise a management protocol for this disorder. Between 1978 and 1992, we prospectively studied 75 patients with HVOO. The obstruction was in the hepatic vein in 24, in the(More)
The relationship between luminance (i.e., the photometric intensity of light) and its perception (i.e., sensations of lightness or brightness) has long been a puzzle. In addition to the mystery of why these perceptual qualities do not scale with luminance in any simple way, " illusions " such as simultaneous brightness contrast, Mach bands,(More)
  • Everson, B W Sirovich, L Kaplan, Shoham, A Bonhoeffer, T Spatio +25 others
  • 2003
motion, both the orientation and the axis of motion were different by 908 between the subtracted stimuli. For example, the response to a texture with 458 oriented bars moving horizontally was subtracted from the response to a texture with 1358 oriented bars moving vertically. Results obtained with difference imaging were verified with single-condition(More)
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