Object Attention Flashcards
What information is required to identify distal stimuli?
Light sources
Reflectance
Surface orientation
Viewing position
What are primary light sources?
Sun, lightbulb
What are secondary light sources?
Moon, walls
What is surface orientation?
Position of surface causes different amount of light to fall on it/reflect off it
What is viewing position?
Scene appears different from different viewing angles
What is the inverse projection problem?
How do you go from the proximal stimulus to identifying the distal stimulus?
What is underdetermination?
Any 2D image may have many potential 3D sources that created it
What is a contour?
Border between light and dark areas in an image
What is Ganzfeld?
Sensory deprivation developed to test for telepathic communication
Some observers blank out or halluinate
Sharp luminance contours are important for visual system
What are microsaccades?
Minute, involuntary, almost imperceptible eye movements that occur during fixations
Purpose is to change the position of the image on the retina
What did Pritchard find about microsaccades?
Observers wore contact lenses with an attached device and a constant image was projected onto the retina
The image disappeared within 3 seconds so eyes respond best to changing stimuli and a static pattern will quickly fade from view
What are illusory contours?
Contours not present on the retina, still affect contour perception
What are the characteristics of figures?
Appear to be in front
Are smaller
Have well-defined shape
Are meaningful
Have more detail
Differ from background in lightness
What is the law of proximity?
Things near to each other tend to be grouped together
What is the law of similarity?
Similar things tend to be grouped together
What is the law of good continuation?
Points that, if connected, would result in either straight or smoothly curving lines, tend to be seen as belonging together; and lines follow the smoothes path
What is the law of closure?
A space enclosed by a contour tends to appear as a figure
What is the law of common fate?
Things that are moving in the same direction tend to be grouped together
What is the law of meaningfulness/familiarity?
Things that are meaningful or familiar tend to form groups
What is the law of Pragnanz?
Every stimulus pattern is seen in such a way that the resulting structure is as simple as possible
What are the pros of Gestalt?
Holistic approach
What are the cons of Gestalt?
Operates post hoc; not good for predictions
Not good at explanations
Vague definitions