Vision Flashcards
Sensation
The ability to detect a stimulus and turn that detection into an experience
Perception
Give meaning to detected sensation
Unconscious actions can
Propel us to act
Bottom up
Triggered by external stimulus which impacts a sense organ
Top down
Triggered internally by memory knowledge or experience
Visual neurons have been found to respond to weak light signals
If accompanied by a loud sound
Synesthesia
One neural pathway from a sense organ diverges and is sent to a different party of the brain that normally processes a different stimulus
Cornea
Transparent thin layer
Bends light inward
Pulls light to pupil
Pupil
Opening in center of iris
Responds to emotions
Iris
Colores
Dilate and contract/regulate light entering eye
Lens
Focus close/bulge
Focus far/flaten
Retina
Sensory receptor for vision
Fovea/ image focuses
Packed with rods and cones
From Retina neural impulses leave eye via optic disk to enter brain
First two layers of retina
Send signals to visual cortex
Don’t respond to light
Third layer of retina
At back
Where rods and cones are located
Cones
Color, fine detail, focus on light,
Red
Green
Blue
Rods
Helps adapt to dark places
Bright places
Dim light
Black and white
Vision as neural impulses
Transduce light waves into neural impulses
Impulses travel across optic nerve to brain
At optic chiasm the brain crosses to opposite sides
Optic chiasm
Fibers carrying info from both left sides of retina go to left optic Tract
Lateral geniculate
Lateral geniculate nucleus of thalamus
The visual cortex
Approximately 30 visual areas in the human brain are organized into a hierchy
Where pathway
Upper dorsal route
Lesion in parietal lobe
Ungerleider and mishkin
Ablation, they removed parietal lobe from half monkeys and half of temporal lobe from other half
Temp-trouble in what
Parietal- trouble in where
Occipital to other lobes
Sing dissociation
Two functions(see touch) Operate in different mechanisms But work together
Double dissociation
Two functions (speech production, language comprehension) Involve different mechanisms Operate independently
Object recognition area
Bottom of temporal lobe
Human faces dealt with
This is one of first stops after info has reached occipital lobe
Other areas include emotional and memory
Inferotemporal cortex in monkeys
Faces/heads
Perception module
Temporal damage causes prosopagnosia
Yeah that was the answer
Look at someone you don’t know
Primary visual cortex-face-recognition area (lower temporal lobe)
Look at someone you know
Primary visual cortex- face-recognition area( lower temporal lobe)- amygdala
Upside down pictures of faces aw sent to areas of brain not sensitive to facial features
Yeah that’s all
Sensory code
Representation of perceived objects through brutal firing
Specificity coding
Specific neurons to specific stimuli
Binocular disparity
Differences between two retinal images of same scene
Occulomotor
Accommodation change focus
Convergence inward eyes
Divergence out ward eyes
Monocular clues
Interposition obstruction of object means it comes first
Linear perspective train tracks
Height/size/shadows
Aerial perspective =mountains
Motion parallax= images move faster when closers
After image
Negative afterimage
Image after stimulus removed
Opposite polarity
