Vision And Visual Pathways In The Brain Flashcards
What is the visual system
The unifying system that integrates all other systems
What does the visual system allow us to do
To learn about, interact, and survive in the world
Used to help make decisions social interaction motor control and posture
Areas vision is important in
Movement detection attentive functions communication subliminal cues Eye hand coordination
What does vision do in movement detection
Alerts us to pleasure, danger,attention
gives us advanced warning
Which fields develop first
Temporal
How is the development of vision important for babies
Babies don’t have central vision right away they
only see about 25 cm
mobile should be close to the side
How long does it take for central vision and color to develop
2 to 4 months
How long does it take for vision to fully myelinate
Two years
How long till the visual system fully develops
11 years
What are the four A’s in attentive functions in vision
Arouse awake alert attend
What percent of our communication is gestures and nonverbal
70
What percent of our communication is actual verbal
30
What are subliminal cues
Cues with in the environment
unconscious
anticipatory in nature
insight when something doesn’t seem right
Effects of visual impairments
Alters quality and amount of input decrease speed of processing changes and decision making changes interactions with people and environment Decreased adaptation
Causes of visual impairments
CVA TBI trauma MS low vision
What is sight
Related to function of eyes
related to visual acuity extraocular muscles ocular impairments
OT’s don’t work with site
What is vision
The whole visual system and how it works with other systems
ambient and focal vision
OT’s work with this:teach compensatory techniques and ways to improve life
What is ambient vision
Where? Subliminal spatiotemporal balance/posture movement detection anticipatory global awareness
What is focal vision
What? liminal or conscious detailed recognition of objects comparisons between things processing memory storage visual completion working memory
What is refraction
Bending of light rays from one medium to another
What are the four areas of refraction
Cornea
aqueous fluid
lens
Vitreous humor
What is myopia
Nearsighted
What is hyperopia
Farsighted
Characteristics of the rods
None in the fovea no color vision night vision Movement detection peripheral or ambient 130 million in each eye
Characteristics of the cones
Present in the fovea 6.5 million in each eye central vision color vision high contrast visual object recognition related to focal vision
What has the highest visual acuity
Fovea
What are the four quadrants of the eye
Temporel
nasal
inferior
superior
What do the visual fields consist of
Fovea macula Paracentral peripheral four quadrants of the eye
Order of the visual pathway
Optic nerve,optic tract, LGN, superior colliculus, parietal or Temporel loops of the optic radiation (geniculocalcarine tracts), occipital cortex
Where does the parietal loop travel to
The frontal lobe
What is the parietal loop for
Inferior visual fields
What does the frontal lobe do
Frontal eye fields Saccades recognition smooth pursuit working memory
Where do the parietal fibers carry info from
Inferior visual fields
Which fibers are the straight fibers
Parietal
Which fibers are the curved fibers
Temporel
What a temporal fibers carry info from
Superior fields
What does the association area do for the parietal loop
Where and how movement detection body image where we are in space postural adjustments global awareness
What Does the association area do for the temporal loop
What is it object recognition size shape texture color sequence awareness of detail
What are the areas of the brain activated in vision
Visual cortical centers Geniculate fibers and occipital lobe Temporal circuitry (what) Parietal circuitry (where and how) prefrontal circuitry limbic system
Order of the visual processing hierarchy from bottom to top
Oculomotor control, visual fields, visual acuity attention=alert and attending scanning pattern recognition visual memory Visuocognition adaptation through vision
What is visual midline shift syndrome
Affects perception of space (shifts persons Midline laterally posteriorly or anteriorly)
effects posture while walking
don’t have visual orientation to space
perceive Midline is towards non affect side
What causes visual midline shift syndrome
Occurs after a head injury such as TBI or stroke
Visual midline shift syndrome is a dysfunction of what kind of vision
Ambient
Symptoms of visual midline shift syndrome
Floor tilts to one side
floor may move
posture shifts to one side
may lean forward or back
What is The overall function of the brain
To filter, organize, and integrate sensory info so it can be used to make an adaptive response to the environment
