THE COGSCI 1B -FINAL EXAM WITH COMPLETE QUESTIONS
AND ANSWERS GRADED A+.
Neural Basis of Perception
Began in 1980's when people were getting better at neural imaging techniques
Pathways of Visual Information (2)
Dorsal Stream (Finding a dolphin's dorsal fin): Spatial location, begin in the
striate cortex and then end in the posterior parietal
Ventral Stream: What it is and form: Striate and then goes to the temporal
cortex
Marr's tri-level information hypothesis
Information processing is held at 3 levels
Computational: Highest most abstract level
Algorithm: What is it. Specifies how the data will be transformed
Implementation: What do we need: How do representations get represented
physically?
Marr's theory of visual processing (Follows from the tri-level information
hypothesis)
Take complex stimuli and represent them
1.
Light and dark features and make a very rough sketch
2.
, 2.5 dimensional thing where you're trying but still bound by the viewing
location, and it changes with movement and motion
3.
Finally 3-dimensional!!! Solves constancy problem that it'll change when you
move because you see all of it
But....bad b/c didn't have neural implementation; was too ideal
Elongation Axis (Marr)
The axis by which most of the objects matter is revolved around
Symmetry Axis (Marrs)
Axis by which it's symmetric in mirror halves
Flow of Visual Information
Starts at the optic nerve, goes through the optic chaism and splits off into 2
before heading into the brainstem before going into the thalamus (LGN: Lateral
geniculate cortex) and then V1 and V2 and splits into dorsal/ventral streams
V1: Primary Visual Cortex
Coming from LGN
Process low level features which feature detectors that try to do orientation
and direction of movement, finding edges and countours
Maps onto the V2/Striate cortex
V2: Striate Cortex
Coming from V1. tries to do more complex arrangements of edges and shape.
Also does depth and determines retinal disparity, which is just because of
binocular vision.
In the extrastriate cortex, uust outisde, they process more shit
Stereopsis
Depth Perception
Trichromatic Theory of Coloar
AND ANSWERS GRADED A+.
Neural Basis of Perception
Began in 1980's when people were getting better at neural imaging techniques
Pathways of Visual Information (2)
Dorsal Stream (Finding a dolphin's dorsal fin): Spatial location, begin in the
striate cortex and then end in the posterior parietal
Ventral Stream: What it is and form: Striate and then goes to the temporal
cortex
Marr's tri-level information hypothesis
Information processing is held at 3 levels
Computational: Highest most abstract level
Algorithm: What is it. Specifies how the data will be transformed
Implementation: What do we need: How do representations get represented
physically?
Marr's theory of visual processing (Follows from the tri-level information
hypothesis)
Take complex stimuli and represent them
1.
Light and dark features and make a very rough sketch
2.
, 2.5 dimensional thing where you're trying but still bound by the viewing
location, and it changes with movement and motion
3.
Finally 3-dimensional!!! Solves constancy problem that it'll change when you
move because you see all of it
But....bad b/c didn't have neural implementation; was too ideal
Elongation Axis (Marr)
The axis by which most of the objects matter is revolved around
Symmetry Axis (Marrs)
Axis by which it's symmetric in mirror halves
Flow of Visual Information
Starts at the optic nerve, goes through the optic chaism and splits off into 2
before heading into the brainstem before going into the thalamus (LGN: Lateral
geniculate cortex) and then V1 and V2 and splits into dorsal/ventral streams
V1: Primary Visual Cortex
Coming from LGN
Process low level features which feature detectors that try to do orientation
and direction of movement, finding edges and countours
Maps onto the V2/Striate cortex
V2: Striate Cortex
Coming from V1. tries to do more complex arrangements of edges and shape.
Also does depth and determines retinal disparity, which is just because of
binocular vision.
In the extrastriate cortex, uust outisde, they process more shit
Stereopsis
Depth Perception
Trichromatic Theory of Coloar
