J. Farley Norman

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We used fMRI to directly compare the neural substrates of three-dimensional (3-D) shape and motion processing for realistic textured objects rotating in depth. Subjects made judgments about several different attributes of these objects, including 3-D shape, the 3-D motion, and the scale of surface texture. For all of these tasks, we equated visual input,(More)
A set of 4 experiments evaluated observers' sensitivity to three-dimensional (3-D) length, using both discrimination and adjustment paradigms with computer-generated optical patterns and real objects viewed directly in a natural environment. Although observers were highly sensitive to small differences in two-dimensional length for line segments presented(More)
An orientation matching task was used to evaluate observers' sensitivity to local surface orientation at designated probe points on randomly shaped 3-D objects that were optically defined by texture, lambertian shading, or specular highlights. These surfaces could be stationary or in motion, and they could be viewed either monocularly or stereoscopically,(More)
Three-dimensional (3D) shape is important for the visual control of grasping and manipulation. We used fMRI to study the processing of 3D shape extracted from disparity in human parietal cortex. Subjects stereoscopically viewed random-line stimuli portraying a 3D structure, a 2D structure in multiple depth planes or a 2D structure in the fixation plane.(More)
The geometric relation between physical and perceived space as specified by binocular stereopsis and structure from motion was investigated. Four experimental tasks were used, each of which required a different aspect of three-dimensional (3-D) structure to be performed accurately. To examine whether the transformation between physical and perceptual space(More)
Three experiments are reported in which observers judged the three-dimensional (3-D) structures of virtual or real objects defined by various combinations of texture, motion, and binocular disparity under a wide variety of conditions. The tasks employed in these studies involved adjusting the depth of an object to match its width, adjusting the planes of a(More)
How do human observers perceive a coherent pattern of motion from a disparate set of local motion measures? Our research has examined how ambiguous motion signals along straight contours are spatially integrated to obtain a globally coherent perception of motion. Observers viewed displays containing a large number of apertures, with each aperture containing(More)
There have been numerous computational models developed in an effort to explain how the human visual system analyzes three-dimensional (3D) surface shape from patterns of image shading, but they all share some important limitations. Models that are applicable to individual static images cannot correctly interpret regions that contain specular highlights,(More)
A single experiment investigated how younger (aged 18-32 years) and older (aged 62-82 years) observers perceive 3D object shape from deforming and static boundary contours. On any given trial, observers were shown two smoothly-curved objects, similar to water-smoothed granite rocks, and were required to judge whether they possessed the "same" or "different"(More)
A series of four experiments was designed to investigate the minimal amounts of information required to perceive the structure of a smoothly curved surface from its pattern of projected motion. In Experiments 1 and 2, observers estimated the amplitudes of sinusoidally corrugated surfaces relative to their periods. Observers' judgments varied linearly with(More)