sight Flashcards
(52 cards)
structures in the eye
pupil –> forms an opening
iris –> controls color of eye and pupil size
muscles behind iris –> control lens
lens –> controls focus
cornea –> bends light to aid the lens in focusing
retina –> membrane in back of they eye
rods vs. cones
rods:
- operate at low levels of light
- night vision
- no color vision
- poor at fine detail
- located in the peripheral of the eye
cones:
- do poorly in low light
- love brightness
- see color
- see detail
- concentrated in the fovea
- located a little
proximity
tend to see stimulus elements that are near each other as part of the same group (groups)
similarity
elements that are similar tend to be grouped together (separating patterns)
closure
we tend to supply missing elements to close / complete a familiar figure (finishing the shape)
continuity
we tend to see elements in ways that produce continuous lines minimal change of direction (we see lines)
common movement / fate
when elements are moving in the same direction at the same rate, we tend to see them as part of a single object
good form or simplicity
the brain seeks the simplest explanation –> an object that is simmetrical may be seen as flat whereas when it isnt it may be seen as continuous lines
How do we see 3D
Different cues:
- binocular cues –> your eyes are in two different positions so you have two different images. your brain uses these cues to establish depth
- monocular cues
- motion parallax –> one of the most important features of depth perception. describes the rate of movement of objects in front of you to determine their distance.
- optic flow –> when you move you get this radial flow in the retina. based on the movement of objects around you, you get an idea of what direction youre headed in (like if youre in a train car looking out the window) **optic flow helps maintain balance
- Y shapes (three intersection points) imply corners
- L shapes (two intersection points) imply connections
- occlusion –> implies something in front
- we also pick up cues from shading and lighting
bottom up processing
we perceive local stimuli and bring them together to produce a whole
top down processes
making use of knowledge to help usperceive (recognizing patterns)
- uses the context effect –> which is using memory and the context of a situation to make a judgement
- ex. seeing a dalmation in a jumbled mess of dots
where is touch processed
parietal cortex
where is taste processed
insular cortex
where is sight processed
occipital lobe
where is smell processed
olfactory bulb (part of the prefrontal cortex)
where is sound processed
temporal lobe
first stop when processing a sensation
everything travels to the thalamus FIRST (except smell)
physical stimulus of audition
changes in air pressure over time
amplitude vs. frequency
amplitude –> loudness
frequency –> pitch (cycles per second)
- fewer cycles per second, lower pitch and vice versa
how does the auditory cortex map sounds
has a map correlating neurons to different frequencies
auditory localization
a combination of intensity and timing of sounds help us determine where theyre coming from
touch
senses pressure, temperature, and pain
- the receptor sends out an axon that goes to the brainstem, to the thalamus, then to the cortex
pain sensation
fast fiber –> mylenated, so information is sent right away (sharp, fast pain)
slow fiber –> nonmylenated, so information takes longer to be processed (duller, diffused pain)
open gate / closed gate
- a larger stimuli can block the firing of smaller nerve fiber firing (closing the gate)
- if you touch a burn it will block pain from being felt
