Object Perception:

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Chapter 6

• Object Perception
• Recognizing the Things We See

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Recognizing 3-D Objects

• Recognition by components
• According to this theory, a view of an object is
  an arrangement of a few simple three-dimensional
  forms called geometrical ions, or geons.

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Recognizing 3-D Objects
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Recognizing 3-D Objects

• Geons can be distinguished from one another in
  any orientation.
• Geons can be recognized when partially occluded
  or obscured or even when intersections are
  disconnected.

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Recognizing 3-D Objects

• View-based recognition
• According to this theory, recognition of a
  three-dimensional object depends on multiple,
  stored views of objects.
• Object recognition occurs when a current pattern
  matches a stored pattern.

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Learning to Recognize

• Visual priming involves an experience at one
  moment influencing subsequent experiences.
• This is a sign of visual plasticity.

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Learning to Recognize

• Vernier acuity is the ability to perceive tiny
  offsets between collinear lines.

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Temporal Pathway and Object Recognition

• The brains temporal stream makes synaptic
  connections in several areas of the temporal
  lobes lower half.
• This is known as the Inferiortemporal (IT)
  cortex.
• Visual perception interfaces with imagery and
  memory in the IT.

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Face Perception

• People are very good at reading faces for
  information about age, gender, and emotional
  state
• Face-inversion effect An upside down face and an
  inverted face are very difficult to recognize.

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Prosopangnosia

• Prosopagnosia a patient can see and describe
  another persons face but not recognize it.
• Configural processing integrating various
  features into a comprehensive, global
  configuration
• Featural processing singling out facial
  components without integrating them

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Greebles

• Greebles are three-dimensional,
  computer-generated creatures that differ by
  gender, family membership, and individual
  identity.
• People trained to identify greebles show
  increased activation of face areas of the brain
  when recognizing new greebles.

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Greebles
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Attention and Object Recognition

• Object-based attention is focused attention that
  increases neural processing of an object and
  enhances recognition.
• Operates at the level of an entire object, not
  just a certain spatial location.

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Attention and Object Recognition

• Intentions and expectations engage a selective
  process called attention that can modulate object
  recognition.

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Attention and Object Recognition

• The initial orientation to unusual objects that
  pop out at you is dubbed preattentive vision.

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Attention and Object Recognition

• Divided Attention - putting attention into 2
  objects / tasks / scenes / etc.

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Attention and Object Recognition

• Selective Attention - focusing attention on one
  objects/tasks/scenes/etc. while ignoring another.

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Attention and Object Recognition

• Attentional Capture - when attention is so
  focused on one object that other objects are
  ignored.

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Attention can induce blindness

• Change blindness is the failure to notice an
  otherwise conspicuous change because of a
  diversion of attention.
• http//www.csc.ncsu.edu/faculty/healey/PP/

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Imagery Visions Little Helper

• Images generated by the imagination can easily be
  confused with real stimuli.
• Imagery and vision seem to share a common neural
  basis.
• Imagery and visual perception both involve the
  primary visual cortex.
• Mental images have less high spatial frequency
  detail than do actual images.
• The missing detail in mental images can be
  encoded in words.

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Imagery and Visual Perception