KANDEL PRINCIPLES OF NEURAL SCIENCE CHAPTER 24: HIGH-LEVEL
VISUAL PROCESSING: FROM VISION TO COGNITION
High-level visual processing is concerned with identifying behaviorally meaningful features of the
environment and thus depends on descending signals that convey information from short-term
working memory, long-term working memory, and executive areas of the cerebral cortex.
Inferior temporal cortex = primary center for object recognition.
The ventral stream extends ventrally and anteriorly from V1 through V2, via V4, into the inferior
temporal cortex.
At the top of the hierarchy, inferior temporal neurons are in a position to integrate a large and diverse
quantity of visual information over a vast region of visual space.
Two basic categories of visual agnosia in humans:
1. Apperceptive = the ability to match or copy complex visual shapes or objects is impaired.
2. Associative = the ability to identify objects is impaired.
Object recognition is intimately intertwined with visual categorization, visual memory, and emotion,
and the outputs of the inferior temporal cortex contribute to these functions.
Invariant attributes of an object cues to the identity and meaning of the object.
Proficiency invariant attributes must be represented independently of other image properties
perceptual constancy.
Size constancy an object placed at different distances from an observer is perceived as having the
same size, even though the object produces images of different absolute size on the retina.
Position constancy objects are recognized as the same regardless of their location in the visual
field.
Form-cue invariance refers to the constancy of a form when the cues that define the form change.
Viewpoint invariance refers to the perceptual constancy of three-dimensional objects observed
from different angles.
VISUAL PROCESSING: FROM VISION TO COGNITION
High-level visual processing is concerned with identifying behaviorally meaningful features of the
environment and thus depends on descending signals that convey information from short-term
working memory, long-term working memory, and executive areas of the cerebral cortex.
Inferior temporal cortex = primary center for object recognition.
The ventral stream extends ventrally and anteriorly from V1 through V2, via V4, into the inferior
temporal cortex.
At the top of the hierarchy, inferior temporal neurons are in a position to integrate a large and diverse
quantity of visual information over a vast region of visual space.
Two basic categories of visual agnosia in humans:
1. Apperceptive = the ability to match or copy complex visual shapes or objects is impaired.
2. Associative = the ability to identify objects is impaired.
Object recognition is intimately intertwined with visual categorization, visual memory, and emotion,
and the outputs of the inferior temporal cortex contribute to these functions.
Invariant attributes of an object cues to the identity and meaning of the object.
Proficiency invariant attributes must be represented independently of other image properties
perceptual constancy.
Size constancy an object placed at different distances from an observer is perceived as having the
same size, even though the object produces images of different absolute size on the retina.
Position constancy objects are recognized as the same regardless of their location in the visual
field.
Form-cue invariance refers to the constancy of a form when the cues that define the form change.
Viewpoint invariance refers to the perceptual constancy of three-dimensional objects observed
from different angles.
