Visual and cognition processing Flashcards
visuocognition
ability to manipulate and integrate visual input with other sensory information to gain knowledge, solve problems, formulate plans and make decisions
visual memory
for mental manipulation of an object, you must be able to create and retain a picture of the stimuli in the mind’s eye while visual analysis is being completed; temporary short term storage
- retrieve from long term memory
pattern recognition
identify salient features, distinguish object from background, problems E and F or 3 and 8
- features: 1) general shape, contour and features 2) specific features
visual scanning/search
accomplished through saccades or movement of the eye toward something of interest
- purpose of saccade = put the object in focus on the retina
- cyclic saccade = ensure that correct identification is being made
attention
- automatic: brainstem level; stimulated by any novel or new object appearing in the periphery
- voluntary: cortical level; purpose is to gather information, locate object in the environment (keys, light switches)
eye innervation
- CN III : superior rectus, inferior rectus, inferior oblique, medial rectus
- CN IV: superior oblique
- CN VI: lateral rectus
refractive errors
light doesn’t focus on retina and objects appear blurred
myopia
nearsightedness
hyperopia
farsightedness
asigmatism
both combined
refraction
process of determining correct lenses (glasses or contact lenses)
accomodation
- ability of lens to focus
- lens loses its flexibility
- person holds things farther away to focus
- additional convex lens for near (bifocal, trifocal, progressive lens)
presbyopia
age related loss of focus at near; about age of 40
convergence
ability to accurately aim the eyes at an object of regard and to track an object as it moves towards and away from the person
strabismus
- cannot align both eyes at the same time
- requires treatment
- constant unilateral strabismus can cause ambylopia if not treated
amblyopia
- “lazy eye”
- good eye and brain inhibit eye from blur
- critical period: birth - 6 yr
- cause by vision not corrected by glasses or elimination of eye turn
- can result in permanent decrease in vision
acquired brain injury
greater than 50% incidence of visual and visual-cognitive disorders in neurologically impaired patients (TBI, CVA, MS)
visual-perceptual dysfunction
one of the most common devastating residual impairments of head injury
visual acuity
- clarity of sight (far/near)
- becomes blurred in various refractive conditions
visual fields
- central/peripheral range
- stroke - loss of the visual field (hemianopsia)
occulomotor
alignment of eyes
fixation
- the ability to steadily and accurately gaze at an oject of regard
- most dysfunctional in nystagmus (uncontrollable shaking of the eyes)
pursuits
- ability to smoothly and accurately track, or follow, a moving object
saccades
- ability to quickly and accurately look, or scan, from one object to another
stereopsis
depth perception
exotropia
form of strabismus where an eye turns out
esotropia
form of strabismus where an eye turns in
hypertropia
form of strabismus where an eye turns up
hypotropia
form of strabismus where an eye turns down
binocularity
integration of accommodation and convergence
visual- motor integration
- eye-hand
- eye-foot
- eye-body coordination
visual-auditory integration
ability to relate and associated what is seen and heard
visual memory
ability to remember and recall information that is seen
visual closure
ability to “fill in the gaps” or complete a visual picture based on seeing only some of the parts
spatial relationships
ability to know “where I am” in relation to objects and space around me and to know where objects are in relation to one another
figure-ground discrimination
the ability to discern form and object from background
What are the 3 most devastating and intolerable visual problems resulting from ABI?
- visual field loss
- intractable double vision
- visual/balance disorders
diplopia
double vision; serious and intolerable condition that can be caused by strabismus, gaze palsy and decompensated binocular skills in patients with brain injury, stroke and other neurologically compromising conditions
what kind of therapy might alleviate diplopia?
- prisms, lenses or vision therapy can oftentimes help the patient achieve fusion (alignment of the eyes)
visual midline shift syndrome
- shift in concept of perceived visual midline
- leans to one side, forward and/or backward
- results from dysfunction of the peripheral visual process
treatment for visual midline shift
-yoked prisms: shifts midline to a more centered position to begin weight bearing on affected side
hemi-inattention
visual neglect
