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Visual Space Perception
Wednesday, 4 June 14
1.The Problem ofVisual Space
Perception
Wednesday, 4 June 14
The Physical World and the Perceptual World
Wednesday, 4 June 14
The Physical World and the Perceptual World
• Physical World - exist outside observer
Wednesday, 4 June 14
The Physical World and the Perceptual World
• Physical World - exist outside observer
• Perceptual World
Wednesday, 4 June...
The Physical World and the Perceptual World
• Physical World - exist outside observer
• Perceptual World
• Experienced by ...
The Physical World and the Perceptual World
• Physical World - exist outside observer
• Perceptual World
• Experienced by ...
The Physical World and the Perceptual World
• Physical World - exist outside observer
• Perceptual World
• Experienced by ...
The Physical World and the Perceptual World
• Physical World - exist outside observer
• Perceptual World
• Experienced by ...
Geometrical Relationships
Wednesday, 4 June 14
Geometrical Relationships
• Physical Space
Wednesday, 4 June 14
Geometrical Relationships
• Physical Space
• Object can be displaced / rotated
without deformation
Wednesday, 4 June 14
Geometrical Relationships
• Physical Space
• Object can be displaced / rotated
without deformation
• Follows Euclidean Geo...
Geometrical Relationships
• Physical Space
• Object can be displaced / rotated
without deformation
• Follows Euclidean Geo...
Geometrical Relationships
• Physical Space
• Object can be displaced / rotated
without deformation
• Follows Euclidean Geo...
Geometrical Relationships
• Physical Space
• Object can be displaced / rotated
without deformation
• Follows Euclidean Geo...
Geometrical Relationships
• Physical Space
• Object can be displaced / rotated
without deformation
• Follows Euclidean Geo...
Geometrical Relationships
• Physical Space
• Object can be displaced / rotated
without deformation
• Follows Euclidean Geo...
Wednesday, 4 June 14
• Relationships among Spaces - Perceived and Physical
Wednesday, 4 June 14
• Relationships among Spaces - Perceived and Physical
• To maintain important distinction between
Wednesday, 4 June 14
• Relationships among Spaces - Perceived and Physical
• To maintain important distinction between
• physical objects (or s...
• Relationships among Spaces - Perceived and Physical
• To maintain important distinction between
• physical objects (or s...
• Relationships among Spaces - Perceived and Physical
• To maintain important distinction between
• physical objects (or s...
• Relationships among Spaces - Perceived and Physical
• To maintain important distinction between
• physical objects (or s...
• Relationships among Spaces - Perceived and Physical
• To maintain important distinction between
• physical objects (or s...
Wednesday, 4 June 14
• Distal objects and scenes can be observed directly
Wednesday, 4 June 14
• Distal objects and scenes can be observed directly
• Perception cannot be observed directly
Wednesday, 4 June 14
• Distal objects and scenes can be observed directly
• Perception cannot be observed directly
• Proximal stimulus patterns...
• Distal objects and scenes can be observed directly
• Perception cannot be observed directly
• Proximal stimulus patterns...
• Distal objects and scenes can be observed directly
• Perception cannot be observed directly
• Proximal stimulus patterns...
• Distal objects and scenes can be observed directly
• Perception cannot be observed directly
• Proximal stimulus patterns...
• Distal objects and scenes can be observed directly
• Perception cannot be observed directly
• Proximal stimulus patterns...
Distal - Proximal Relationships
Wednesday, 4 June 14
Distal - Proximal Relationships
• Projective Geometry: Geometrical Optics
Wednesday, 4 June 14
Distal - Proximal Relationships
• Projective Geometry: Geometrical Optics
• The light falling on an eye can come
Wednesday...
Distal - Proximal Relationships
• Projective Geometry: Geometrical Optics
• The light falling on an eye can come
• directl...
Distal - Proximal Relationships
• Projective Geometry: Geometrical Optics
• The light falling on an eye can come
• directl...
Distal - Proximal Relationships
• Projective Geometry: Geometrical Optics
• The light falling on an eye can come
• directl...
Distal - Proximal Relationships
• Projective Geometry: Geometrical Optics
• The light falling on an eye can come
• directl...
Wednesday, 4 June 14
• To study perception - it is necessary to consider
only the rays that enter the eye of a viewer.
Wednesday, 4 June 14
• To study perception - it is necessary to consider
only the rays that enter the eye of a viewer.
• Fig. shows the distal-...
• To study perception - it is necessary to consider
only the rays that enter the eye of a viewer.
• Fig. shows the distal-...
• To study perception - it is necessary to consider
only the rays that enter the eye of a viewer.
• Fig. shows the distal-...
• To study perception - it is necessary to consider
only the rays that enter the eye of a viewer.
• Fig. shows the distal-...
• To study perception - it is necessary to consider
only the rays that enter the eye of a viewer.
• Fig. shows the distal-...
• To study perception - it is necessary to consider
only the rays that enter the eye of a viewer.
• Fig. shows the distal-...
Wednesday, 4 June 14
• Proximal Geometry - Geometry of Perspective
Wednesday, 4 June 14
• Proximal Geometry - Geometry of Perspective
Wednesday, 4 June 14
• Proximal Geometry - Geometry of Perspective
• represented in a hypothetical projection
plane erected b/w the viewer
and ...
• Proximal Geometry - Geometry of Perspective
• represented in a hypothetical projection
plane erected b/w the viewer
and ...
• Proximal Geometry - Geometry of Perspective
• represented in a hypothetical projection
plane erected b/w the viewer
and ...
• Proximal Geometry - Geometry of Perspective
• represented in a hypothetical projection
plane erected b/w the viewer
and ...
“The Problem ofVisual Space Perception”
Wednesday, 4 June 14
“The Problem ofVisual Space Perception”
• To relate - the experienced qualities - of - visual space to specific
aspects of ...
“The Problem ofVisual Space Perception”
• To relate - the experienced qualities - of - visual space to specific
aspects of ...
“The Problem ofVisual Space Perception”
• To relate - the experienced qualities - of - visual space to specific
aspects of ...
“The Problem ofVisual Space Perception”
• To relate - the experienced qualities - of - visual space to specific
aspects of ...
2. Spatial Localization :Visual Directions
Wednesday, 4 June 14
Visual Directions
Wednesday, 4 June 14
Visual Directions
• Visual directions experienced when viewing a
scene with two eyes
Wednesday, 4 June 14
Visual Directions
• Visual directions experienced when viewing a
scene with two eyes
• Eyes are in different positions in ...
Visual Directions
• Visual directions experienced when viewing a
scene with two eyes
• Eyes are in different positions in ...
Monocular Localization of Directions
Wednesday, 4 June 14
Monocular Localization of Directions
• MonocularVisual Field
Wednesday, 4 June 14
Monocular Localization of Directions
• MonocularVisual Field
• The portion of the world that is visible to a single
statio...
Monocular Localization of Directions
• MonocularVisual Field
• The portion of the world that is visible to a single
statio...
Monocular Localization of Directions
• MonocularVisual Field
• The portion of the world that is visible to a single
statio...
Monocular Localization of Directions
• MonocularVisual Field
• The portion of the world that is visible to a single
statio...
Wednesday, 4 June 14
• BinocularVisual Field
Wednesday, 4 June 14
• BinocularVisual Field
• Superimposed monocular fields of
two eyes
Wednesday, 4 June 14
• BinocularVisual Field
• Superimposed monocular fields of
two eyes
• Max width = ~200º with 120º of
binocular field
Wednesd...
Wednesday, 4 June 14
• Objective Directions:Visual Lines
Wednesday, 4 June 14
• Objective Directions:Visual Lines
• Visual Line - locus of distal points that stimulate a given point on
the retina of a...
• Objective Directions:Visual Lines
• Visual Line - locus of distal points that stimulate a given point on
the retina of a...
• Objective Directions:Visual Lines
• Visual Line - locus of distal points that stimulate a given point on
the retina of a...
• Relationship between distal points and their representation in the
proximal stimulus for a single eye
Wednesday, 4 June ...
Wednesday, 4 June 14
• Subjective Directions: Visual directions
Wednesday, 4 June 14
• Subjective Directions: Visual directions
• Perceived visual directions are the subjective directions of points
in space ...
• Subjective Directions: Visual directions
• Perceived visual directions are the subjective directions of points
in space ...
• Subjective Directions: Visual directions
• Perceived visual directions are the subjective directions of points
in space ...
• Proximal - perceptual relations described by visual directions.
• Perceived directions are described relative to the pri...
Wednesday, 4 June 14
• Vergence Movements
Wednesday, 4 June 14
• Vergence Movements
• Conjunctive eye movements that maintain a constant
convergence angle
Wednesday, 4 June 14
• Vergence Movements
• Conjunctive eye movements that maintain a constant
convergence angle
• Vergence Movements are disju...
• tan y/2 = A / 2D
• ~ y = A/D for small y in radians
Wednesday, 4 June 14
Binocular Localizarion
Wednesday, 4 June 14
Binocular Localizarion
• Well’s Experiments
Wednesday, 4 June 14
Binocular Localizarion
• Well’s Experiments
• Fusion
Wednesday, 4 June 14
Binocular Localizarion
• Well’s Experiments
• Fusion
• Horopter andVieth-Muller Circle
Wednesday, 4 June 14
Binocular Localizarion
• Well’s Experiments
• Fusion
• Horopter andVieth-Muller Circle
• Next -- 3. Fusion and Horopters
W...
Wednesday, 4 June 14
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Visual space perception

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Visual space perception

  1. 1. Visual Space Perception Wednesday, 4 June 14
  2. 2. 1.The Problem ofVisual Space Perception Wednesday, 4 June 14
  3. 3. The Physical World and the Perceptual World Wednesday, 4 June 14
  4. 4. The Physical World and the Perceptual World • Physical World - exist outside observer Wednesday, 4 June 14
  5. 5. The Physical World and the Perceptual World • Physical World - exist outside observer • Perceptual World Wednesday, 4 June 14
  6. 6. The Physical World and the Perceptual World • Physical World - exist outside observer • Perceptual World • Experienced by the observer Wednesday, 4 June 14
  7. 7. The Physical World and the Perceptual World • Physical World - exist outside observer • Perceptual World • Experienced by the observer • Produced by activity in eye-brain system - when - patterned light simulates the eye of observer Wednesday, 4 June 14
  8. 8. The Physical World and the Perceptual World • Physical World - exist outside observer • Perceptual World • Experienced by the observer • Produced by activity in eye-brain system - when - patterned light simulates the eye of observer • Consist of - view at a given moment Wednesday, 4 June 14
  9. 9. The Physical World and the Perceptual World • Physical World - exist outside observer • Perceptual World • Experienced by the observer • Produced by activity in eye-brain system - when - patterned light simulates the eye of observer • Consist of - view at a given moment • 4D World - “3D Space” + Time Wednesday, 4 June 14
  10. 10. Geometrical Relationships Wednesday, 4 June 14
  11. 11. Geometrical Relationships • Physical Space Wednesday, 4 June 14
  12. 12. Geometrical Relationships • Physical Space • Object can be displaced / rotated without deformation Wednesday, 4 June 14
  13. 13. Geometrical Relationships • Physical Space • Object can be displaced / rotated without deformation • Follows Euclidean Geometry - Parallel Postulate - Parallel Lines do not meet Wednesday, 4 June 14
  14. 14. Geometrical Relationships • Physical Space • Object can be displaced / rotated without deformation • Follows Euclidean Geometry - Parallel Postulate - Parallel Lines do not meet • Points in space can be assigned coordinates in Cartesian coordinate system and distance between points can be measured w.r.t origin Wednesday, 4 June 14
  15. 15. Geometrical Relationships • Physical Space • Object can be displaced / rotated without deformation • Follows Euclidean Geometry - Parallel Postulate - Parallel Lines do not meet • Points in space can be assigned coordinates in Cartesian coordinate system and distance between points can be measured w.r.t origin • Perceptual (Visual) Space Wednesday, 4 June 14
  16. 16. Geometrical Relationships • Physical Space • Object can be displaced / rotated without deformation • Follows Euclidean Geometry - Parallel Postulate - Parallel Lines do not meet • Points in space can be assigned coordinates in Cartesian coordinate system and distance between points can be measured w.r.t origin • Perceptual (Visual) Space • Geometry of Physical space w.r.t. Perceiver Wednesday, 4 June 14
  17. 17. Geometrical Relationships • Physical Space • Object can be displaced / rotated without deformation • Follows Euclidean Geometry - Parallel Postulate - Parallel Lines do not meet • Points in space can be assigned coordinates in Cartesian coordinate system and distance between points can be measured w.r.t origin • Perceptual (Visual) Space • Geometry of Physical space w.r.t. Perceiver • Direction and Distance in Polar Coordinates Wednesday, 4 June 14
  18. 18. Geometrical Relationships • Physical Space • Object can be displaced / rotated without deformation • Follows Euclidean Geometry - Parallel Postulate - Parallel Lines do not meet • Points in space can be assigned coordinates in Cartesian coordinate system and distance between points can be measured w.r.t origin • Perceptual (Visual) Space • Geometry of Physical space w.r.t. Perceiver • Direction and Distance in Polar Coordinates • By specifying an origin that corresponds to a perceiver - visual space can be measured in terms of angular direction and radial distance Wednesday, 4 June 14
  19. 19. Wednesday, 4 June 14
  20. 20. • Relationships among Spaces - Perceived and Physical Wednesday, 4 June 14
  21. 21. • Relationships among Spaces - Perceived and Physical • To maintain important distinction between Wednesday, 4 June 14
  22. 22. • Relationships among Spaces - Perceived and Physical • To maintain important distinction between • physical objects (or scenes) and Wednesday, 4 June 14
  23. 23. • Relationships among Spaces - Perceived and Physical • To maintain important distinction between • physical objects (or scenes) and • pattern of reflected light impinging on the retinal surface Wednesday, 4 June 14
  24. 24. • Relationships among Spaces - Perceived and Physical • To maintain important distinction between • physical objects (or scenes) and • pattern of reflected light impinging on the retinal surface • Physical Objects (or scenes) are described as distal stimuli and Wednesday, 4 June 14
  25. 25. • Relationships among Spaces - Perceived and Physical • To maintain important distinction between • physical objects (or scenes) and • pattern of reflected light impinging on the retinal surface • Physical Objects (or scenes) are described as distal stimuli and • Impinging Patterns of light are described as proximal stimuli Wednesday, 4 June 14
  26. 26. • Relationships among Spaces - Perceived and Physical • To maintain important distinction between • physical objects (or scenes) and • pattern of reflected light impinging on the retinal surface • Physical Objects (or scenes) are described as distal stimuli and • Impinging Patterns of light are described as proximal stimuli • Perception refers to the process or act of perceiving, whose content is the percept, the conscious experience of the distal object or scene. Wednesday, 4 June 14
  27. 27. Wednesday, 4 June 14
  28. 28. • Distal objects and scenes can be observed directly Wednesday, 4 June 14
  29. 29. • Distal objects and scenes can be observed directly • Perception cannot be observed directly Wednesday, 4 June 14
  30. 30. • Distal objects and scenes can be observed directly • Perception cannot be observed directly • Proximal stimulus patterns can be observed by Wednesday, 4 June 14
  31. 31. • Distal objects and scenes can be observed directly • Perception cannot be observed directly • Proximal stimulus patterns can be observed by • projecting light from distal stimuli Wednesday, 4 June 14
  32. 32. • Distal objects and scenes can be observed directly • Perception cannot be observed directly • Proximal stimulus patterns can be observed by • projecting light from distal stimuli • onto a surface - a screen or projection place that represents the retinal surface Wednesday, 4 June 14
  33. 33. • Distal objects and scenes can be observed directly • Perception cannot be observed directly • Proximal stimulus patterns can be observed by • projecting light from distal stimuli • onto a surface - a screen or projection place that represents the retinal surface • Each component of perceptual act - distal stimulus, proximal stimulus, percept, response - can be described geometrically Wednesday, 4 June 14
  34. 34. • Distal objects and scenes can be observed directly • Perception cannot be observed directly • Proximal stimulus patterns can be observed by • projecting light from distal stimuli • onto a surface - a screen or projection place that represents the retinal surface • Each component of perceptual act - distal stimulus, proximal stimulus, percept, response - can be described geometrically • The relationship between adjacent components in a sequence may be described by mapping the geometry of one component into geometry of the next component Wednesday, 4 June 14
  35. 35. Distal - Proximal Relationships Wednesday, 4 June 14
  36. 36. Distal - Proximal Relationships • Projective Geometry: Geometrical Optics Wednesday, 4 June 14
  37. 37. Distal - Proximal Relationships • Projective Geometry: Geometrical Optics • The light falling on an eye can come Wednesday, 4 June 14
  38. 38. Distal - Proximal Relationships • Projective Geometry: Geometrical Optics • The light falling on an eye can come • directly from an emitting source or Wednesday, 4 June 14
  39. 39. Distal - Proximal Relationships • Projective Geometry: Geometrical Optics • The light falling on an eye can come • directly from an emitting source or • after being refracted through a medium like air, water Wednesday, 4 June 14
  40. 40. Distal - Proximal Relationships • Projective Geometry: Geometrical Optics • The light falling on an eye can come • directly from an emitting source or • after being refracted through a medium like air, water • The 2D pattern of light reflected to an eye from 3D arrangement of objects in the world is described by projective geometry Wednesday, 4 June 14
  41. 41. Distal - Proximal Relationships • Projective Geometry: Geometrical Optics • The light falling on an eye can come • directly from an emitting source or • after being refracted through a medium like air, water • The 2D pattern of light reflected to an eye from 3D arrangement of objects in the world is described by projective geometry • We apply geometrical analysis to light - it is called as Geometrical Optics Wednesday, 4 June 14
  42. 42. Wednesday, 4 June 14
  43. 43. • To study perception - it is necessary to consider only the rays that enter the eye of a viewer. Wednesday, 4 June 14
  44. 44. • To study perception - it is necessary to consider only the rays that enter the eye of a viewer. • Fig. shows the distal-proximal realtions for a single eye Wednesday, 4 June 14
  45. 45. • To study perception - it is necessary to consider only the rays that enter the eye of a viewer. • Fig. shows the distal-proximal realtions for a single eye • The viewer is looking at house - a distal object Wednesday, 4 June 14
  46. 46. • To study perception - it is necessary to consider only the rays that enter the eye of a viewer. • Fig. shows the distal-proximal realtions for a single eye • The viewer is looking at house - a distal object • Light is reflected everywhere - but the perceiver is simulated only by light that - enters the eye Wednesday, 4 June 14
  47. 47. • To study perception - it is necessary to consider only the rays that enter the eye of a viewer. • Fig. shows the distal-proximal realtions for a single eye • The viewer is looking at house - a distal object • Light is reflected everywhere - but the perceiver is simulated only by light that - enters the eye • Light is represented by the rays that converge toward the nodal point of the eye and simulate cells on the retina of the viewer. Wednesday, 4 June 14
  48. 48. • To study perception - it is necessary to consider only the rays that enter the eye of a viewer. • Fig. shows the distal-proximal realtions for a single eye • The viewer is looking at house - a distal object • Light is reflected everywhere - but the perceiver is simulated only by light that - enters the eye • Light is represented by the rays that converge toward the nodal point of the eye and simulate cells on the retina of the viewer. • The pattern of light simulating cells on retina constitutes the proximal stimulus Wednesday, 4 June 14
  49. 49. • To study perception - it is necessary to consider only the rays that enter the eye of a viewer. • Fig. shows the distal-proximal realtions for a single eye • The viewer is looking at house - a distal object • Light is reflected everywhere - but the perceiver is simulated only by light that - enters the eye • Light is represented by the rays that converge toward the nodal point of the eye and simulate cells on the retina of the viewer. • The pattern of light simulating cells on retina constitutes the proximal stimulus • inverted w.r.t. orientation of distal object Wednesday, 4 June 14
  50. 50. Wednesday, 4 June 14
  51. 51. • Proximal Geometry - Geometry of Perspective Wednesday, 4 June 14
  52. 52. • Proximal Geometry - Geometry of Perspective Wednesday, 4 June 14
  53. 53. • Proximal Geometry - Geometry of Perspective • represented in a hypothetical projection plane erected b/w the viewer and the distal stimulus Wednesday, 4 June 14
  54. 54. • Proximal Geometry - Geometry of Perspective • represented in a hypothetical projection plane erected b/w the viewer and the distal stimulus • In above figure, the projection is on frontoparallel plane or picture plane - a plane that is perpendicular to line of sight of the viewer Wednesday, 4 June 14
  55. 55. • Proximal Geometry - Geometry of Perspective • represented in a hypothetical projection plane erected b/w the viewer and the distal stimulus • In above figure, the projection is on frontoparallel plane or picture plane - a plane that is perpendicular to line of sight of the viewer • the upright pattern in proximal stimulus is described by 2D geometry of perspective Wednesday, 4 June 14
  56. 56. • Proximal Geometry - Geometry of Perspective • represented in a hypothetical projection plane erected b/w the viewer and the distal stimulus • In above figure, the projection is on frontoparallel plane or picture plane - a plane that is perpendicular to line of sight of the viewer • the upright pattern in proximal stimulus is described by 2D geometry of perspective • In this pattern, the size of a distal object is represented according Wednesday, 4 June 14
  57. 57. “The Problem ofVisual Space Perception” Wednesday, 4 June 14
  58. 58. “The Problem ofVisual Space Perception” • To relate - the experienced qualities - of - visual space to specific aspects of simulation - and - to processes occurring in the visual space system Wednesday, 4 June 14
  59. 59. “The Problem ofVisual Space Perception” • To relate - the experienced qualities - of - visual space to specific aspects of simulation - and - to processes occurring in the visual space system • To simplify these tasks of identifying these components - visual space perception is divided into two different ways Wednesday, 4 June 14
  60. 60. “The Problem ofVisual Space Perception” • To relate - the experienced qualities - of - visual space to specific aspects of simulation - and - to processes occurring in the visual space system • To simplify these tasks of identifying these components - visual space perception is divided into two different ways • Binocular and Monocular Perception Wednesday, 4 June 14
  61. 61. “The Problem ofVisual Space Perception” • To relate - the experienced qualities - of - visual space to specific aspects of simulation - and - to processes occurring in the visual space system • To simplify these tasks of identifying these components - visual space perception is divided into two different ways • Binocular and Monocular Perception • Static and Kinetic Analysis Wednesday, 4 June 14
  62. 62. 2. Spatial Localization :Visual Directions Wednesday, 4 June 14
  63. 63. Visual Directions Wednesday, 4 June 14
  64. 64. Visual Directions • Visual directions experienced when viewing a scene with two eyes Wednesday, 4 June 14
  65. 65. Visual Directions • Visual directions experienced when viewing a scene with two eyes • Eyes are in different positions in space Wednesday, 4 June 14
  66. 66. Visual Directions • Visual directions experienced when viewing a scene with two eyes • Eyes are in different positions in space • When looking at a single point, the two eyes must be oriented in slightly different directions Wednesday, 4 June 14
  67. 67. Monocular Localization of Directions Wednesday, 4 June 14
  68. 68. Monocular Localization of Directions • MonocularVisual Field Wednesday, 4 June 14
  69. 69. Monocular Localization of Directions • MonocularVisual Field • The portion of the world that is visible to a single stationary eye defines the monocular visual field Wednesday, 4 June 14
  70. 70. Monocular Localization of Directions • MonocularVisual Field • The portion of the world that is visible to a single stationary eye defines the monocular visual field • Perimetry Wednesday, 4 June 14
  71. 71. Monocular Localization of Directions • MonocularVisual Field • The portion of the world that is visible to a single stationary eye defines the monocular visual field • Perimetry • Field of monocular vision Wednesday, 4 June 14
  72. 72. Monocular Localization of Directions • MonocularVisual Field • The portion of the world that is visible to a single stationary eye defines the monocular visual field • Perimetry • Field of monocular vision • Blind spot Wednesday, 4 June 14
  73. 73. Wednesday, 4 June 14
  74. 74. • BinocularVisual Field Wednesday, 4 June 14
  75. 75. • BinocularVisual Field • Superimposed monocular fields of two eyes Wednesday, 4 June 14
  76. 76. • BinocularVisual Field • Superimposed monocular fields of two eyes • Max width = ~200º with 120º of binocular field Wednesday, 4 June 14
  77. 77. Wednesday, 4 June 14
  78. 78. • Objective Directions:Visual Lines Wednesday, 4 June 14
  79. 79. • Objective Directions:Visual Lines • Visual Line - locus of distal points that stimulate a given point on the retina of a single eye Wednesday, 4 June 14
  80. 80. • Objective Directions:Visual Lines • Visual Line - locus of distal points that stimulate a given point on the retina of a single eye • PrincipalVisual Line (PVL) - locus of distal points that stimulate the center of foveola of a single eye Wednesday, 4 June 14
  81. 81. • Objective Directions:Visual Lines • Visual Line - locus of distal points that stimulate a given point on the retina of a single eye • PrincipalVisual Line (PVL) - locus of distal points that stimulate the center of foveola of a single eye • Line passing through the center of the foveola, the nodal point of the eye and the fixated point is Visual Axis Wednesday, 4 June 14
  82. 82. • Relationship between distal points and their representation in the proximal stimulus for a single eye Wednesday, 4 June 14
  83. 83. Wednesday, 4 June 14
  84. 84. • Subjective Directions: Visual directions Wednesday, 4 June 14
  85. 85. • Subjective Directions: Visual directions • Perceived visual directions are the subjective directions of points in space (up, down, left, right) Wednesday, 4 June 14
  86. 86. • Subjective Directions: Visual directions • Perceived visual directions are the subjective directions of points in space (up, down, left, right) • When eye is directed at a given point, the image of the point falls on the center of the fovea Wednesday, 4 June 14
  87. 87. • Subjective Directions: Visual directions • Perceived visual directions are the subjective directions of points in space (up, down, left, right) • When eye is directed at a given point, the image of the point falls on the center of the fovea • The subjective direction associated with this fixation is called PrincipalVisual Direction (pvd). Wednesday, 4 June 14
  88. 88. • Proximal - perceptual relations described by visual directions. • Perceived directions are described relative to the principal visual direction (pvd) • Point A appears to be ߺ to the left and øº above pvd Wednesday, 4 June 14
  89. 89. Wednesday, 4 June 14
  90. 90. • Vergence Movements Wednesday, 4 June 14
  91. 91. • Vergence Movements • Conjunctive eye movements that maintain a constant convergence angle Wednesday, 4 June 14
  92. 92. • Vergence Movements • Conjunctive eye movements that maintain a constant convergence angle • Vergence Movements are disjunctive eye movements in which the convergence angle changes i.e. the eye muscle move the eyes equally inward or outward. Wednesday, 4 June 14
  93. 93. • tan y/2 = A / 2D • ~ y = A/D for small y in radians Wednesday, 4 June 14
  94. 94. Binocular Localizarion Wednesday, 4 June 14
  95. 95. Binocular Localizarion • Well’s Experiments Wednesday, 4 June 14
  96. 96. Binocular Localizarion • Well’s Experiments • Fusion Wednesday, 4 June 14
  97. 97. Binocular Localizarion • Well’s Experiments • Fusion • Horopter andVieth-Muller Circle Wednesday, 4 June 14
  98. 98. Binocular Localizarion • Well’s Experiments • Fusion • Horopter andVieth-Muller Circle • Next -- 3. Fusion and Horopters Wednesday, 4 June 14
  99. 99. Wednesday, 4 June 14

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