320 final - ch 10

• Cue approach to depth perception

  Focuses on identifying information in the retinal image that is correlated with depth in the scene
• Monocular Depth cues

  • Occlusion
  • Relative height
  • Relative size
  • Atmospheric perspective
  • Perspective Convergence
• Occlusion


  Depth cue in which one object hides or partially hides another object from view, causing the hidden object to be perceived as being farther away. A monocular depth cue.
• Oculomotor cues


  Depth cue that depends on our ability to sense the position of our eyes and the tension in our eye muscles
• Oculomotor cues

  • Accommodation
  • Convergence
• Convergence

  Inward movement of the eyes that occurs when we look at nearby objects
• Accommodation


  The change in shape of the lens that occurs when we focus on objects at various distances
• Pictorial cues


  • Overlap
  • Relative height
  • Relative size
• Relative height


  Objects that have bases below the horizon appear to be farther away when they are higher in the field of view. Objects that have bases above the horizon appear to be farther away when they are lower in the field of view.
• Familiar size

  A depth cue in which judgment of distance is based on knowledge of the sizes of objects
• Perspective convergence


  The perception that parallel lines in the distance converge as distance increases
• Linear perspective


  Things get smaller when they are away
• Atmospheric perspective


  Objects that are farther away look more blurred and bluer than objects that are closer because we look through more air and particles to see them
• Texture gradient


  The visual pattern formed by a regularly textured surface that extends away from the observer. This pattern provides information for distance because the elements in a texture gradient appear smaller as distance from the observer increases.
• Motion parallax


  As an observer moves, nearby objects appear to move rapidly across the visual field whereas far objects appear to move more slowly
• Stereoscopic vision


  Two-eyed depth perception involving mechanisms that take into account differences in the images formed on the left and right eyes
• Stereoscopic depth perception


  Depth perception created by input from both eyes
• Binocular disparity


  Occurs when the retinal images of an object fall on disparate points on the two retinas; the difference in images on the left and right retinas
• Corresponding retinal points


  The points on each retina that would overlap if one retina were slid on top of the other. Receptors at corresponding points send their signals to the same location in the brain.
• Non corresponding points

  Two points, one on each retina, that would not overlap if the retinas were slid onto each other. Also called disparate points.
• Crossed disparity


  Disparity that occurs when one object is being fixated, and is therefore on the horopter, and another object is located in front of the horopter, closer to the observer.
• Uncrossed disparity


  Disparity that occurs when one object is being fixated, and is therefore on the horopter, and another object is located behind the horopter, farther from the observer.
• Random-dot stereogram


  A pair of stereoscopic images made up of random dots. When one section of this pattern is shifted slightly in one direction, the resulting disparity causes the shifted section to appear above or below the rest of the pattern when the patterns are viewed in a stereoscope.
• Binocular depth cells (disparity-selective cells)


  A neuron in the visual cortex that responds best to stimuli that fall on points separated by a specific degree of disparity on the two retinas. Also called a disparity-selective cell.
• Emmert's law


  S = R x D, where S = perceived size, R = retinal image, D = perceived distance