Vision Flashcards
(23 cards)
Early Visual Processing
Sensation > optic nerve (once exiting the optic nerve its LVP)
Late Visual Processing
Perception > visual cortex or occipital lobe
V1
responds to simple patterns of oriented edges, contains specialized regions that process particular attributes or features (edges, angels, etc.)
Ventral Pathway
WHAT pathway, occipital to temporal lobe (shape, size, visual details)
Ventral Damage
impaired performance on visual object recognition or matching tasks
Dorsal Pathway
WHERE pathway, occipital to parietal lobe (location space, movement info)
Dorsal Damage
impaired on visually guided action (picking up an object
Bottom-Up Processing
Influence of information from external environment on perception
Top-Down Processing
Use of previous knowledge influencing perception
Constructivist Theory of Perception
We use what we know, and current context to predict how to perceive sensory data (top down processing)
Blindsight
Damaged V1 removes conscious perception of visual objects
- able to answer questions about whats seen but swear they are just guessing
- Blindsight leads to deficits in consciously processing incoming visual information but not imagery (imagination)
Akinetopsia
visual motion blindness: perceives motion as a series of stationary objects
- damaged dorsal pathway
Optic Ataxia
inability to reach for objects with the ability to name objects
- damaged dorsal pathway
Visual Agnosia
Difficulties recognizing everyday objects
- damaged ventral pathway
Prosopagnosia
FFA damage causes deficit in recognizing faces
- damaged ventral pathway
Apperceptive agnosia
problems perceiving objects (faces for prosopagnosia look contorted)
- Impairment in grouping visual features to form meaningful perception, problems with discrimination
Associative Agnosia
problems assigning meaning or labeling objects
- An inability to associate visual input with meaning
- Problems drawing objects from memory, naming objects, indicating functions of objects
Gestalt Principle
- States the whole that is perceived is greater than the sum of its parts
- Based on knowledge and experience (top-down processes) and shared among people
Direct Model
rejects that brain constructs mental model of world and says perception is direct between stimulus and action (bottom up)
Motion Parallax
the fact that objects far away change position more slowly on your retina as you move
Template Matching Theory
Every object has templates
Prototype Theory
We match objects to average prototype idea
