visual processing testing Flashcards
what eye movements are tested with the DEM
saccades
saccades
rapid yoked eye movements that move the fovea to an object of interest. they are used during reading tasks to may be initiated by sudden visual, auditory, or peripheral stimulus. The DEM evaluates this
DEM
- patient is asked to call off a series of numbers as fast as he can without using a finger to hope with tracking
- the first series of numbers are arranged in vertical columns and tests the patients ability to automatically call off numbers (random automaticity of naming (RAN)). The Sedona series of numbers are arranged in horizontal columns to assess RAN + saccades
- The patient’s response time and number of errors for each series are recorded and used to calculate an adjusted horizontal/vertical time ratio that taken into account errors. This ratio is compared to normative values to determine whether saccades are impaired.
tests for saccades
DEM, NSUCO test, and King Devick test
DEM scores
a low horizontal/vertical time ratio on DEM testing is considered good. Any score below the 50% percentile is considered abnormal, and any score below the 15% percentile is considered significantly poor
smooth pursuits
slow tracking movements that maintain fixation of the five on a moving object. Although they are considered voluntary eye movements, few people can perform smooth pursuits without a moving stimulus. The NSUCO oculomotor test and Groffman tracings can be used to evaluate pursuits
versions
are binocular eye movements that result in the visual axes of both eyes moving in the same direction (conjugate). They enlarge the field of view and move the fovea of each eye to an object for fixation
vergences
align the visual axes of both eyes to obtain binocular fixation and fusion. They are disconjugate eye movements, meaning that the visual axes of each eye move in opposite directions (convergence, divergence)
ductions
monocular rotations or movements of the eye. Remember that abduction moves the eye away from the midline, adduction moves the eye towards the midline, elevation moves the eye up, depression moves the eye down, incycloduction moves the top of the eye inward, and excycloduction rotates the top of the eye outward
VOR
stabilizes images on the fovea during brief head movements by producing an eye movement of equal magnitude to the head movement, but in the opposite movement of endolymph within the semicircular canals of the ear during head movement. The VOR does NOT require a visual stimulus (It will occur in response to head movement even if the eyes are closed). Remember after 30 seconds of sustained head movement, the VOR begins to fade and the optokinetic reflex continues the eye movements in response to the continuous head movements
optokinetic reflex
stabilizes the image on the fovea duding prolonged head movements > 30s after the VOR response has faded
difference between the optokinetic nystagmus and VOR
- optokinetic reflex is responsible for maintaining an image on the fovea with prolonged head movements >30 seconds when the VOR is no longer active
- optokinetic nystagmus maintains the image of a moving object on the fovea when the head is still
dyslexia
a term that has been applied to a reading disability. It is best described as a cognitive deficit related to the process of spelling and reading. Dyslexia should be applied in two specific situations
Learning related vision problems (LRVPs)
broadly categorized as deficiencies in visual efficiency nd visual information processing
visual efficiency
basic visual physiological processes that allow the patient to see comfortably and clearly and include refractive error, accommodation, vergence, and motility. Visual efficiency deficits account for 15-20% of all LVRPs and most commonly involves accommodative dysfunction and convergence insufficiency
VIP
the ability to discriminate, recognize, and interpret visual stimuli. It incorporates visual spatial orientation, visual analysis, rapid naming (quickly recognizing a visual signal), and executive functions (the brain processing necessary to accomplish goal-directed behavior). VIP deficits account for 20% of all LRVPs and are considered developmental in etiology
what is a good test to detect LRVPs
Denver
VIP skills
directionality, visual motor integration, bilateral integration, and fine-motor coordination are all classified as visual information processing skills
visual spatial skills
bilateral integration
laterality
directionality
bilateral integration
visual spatial skill
-awareness and ability to use both sides of the body independently or together
laterality
visual spatial skill
-understanding ones own R and L
directionality
visual spatial skill
-ability to distinguish between L and R on an object in space
signs and symptoms of visual spatial problem
lack of coordination and balance, not knowing R from L, reversing letters when writing
testing for visual spatial provlems
- bilateral integration tests: standing test (body control), chalkboard circle test, standing angles in the snow
- laterality: Piaget’s RL awareness test
- Directionality: Jordan LR reversal test, reversals frequency test, Piaget’s LR awareness test
visual analysis skills
aka visual perception
- involve gathering and evaluating visual information from the environment, allowing us to ask “what am I seeing, Where is it located, and why is it important?”
- describes the ability to use visual memory to identify objects in the environment when certain characteristics are missing or when distracting objects are present. Visual analysis skills are important for letter and number recognition, mathematics, maintaining concentration, and competing tasks efficiently.
categories of visual perception
visual discrimination visual closure visual form constancy visual figure ground visual spatial relations visual memory
visual discrimination
the ability to identify features of an object (size shape color) that differentiate it from other objects
visual closure
the ability to identify an object when portions of it are missing v
visual form constancy
the ability to identify an object based on its shape, even when the size, color, or orientation of the object changes
visual figure ground
the ability to identify an object from background with distracting stimuli, while still attending to the interaction between the object and the background
visual spatial relations
the ability to identify an object based on its orientation when its surrounding by other objects of similar shape, size, and color
visual memory
the ability to recall visual objects that were previously present
signs and symptoms of visual perception problems
difficulty learning the alphabet or recognizing words, difficult writing, poor number recognition, difficulty with math, poor reading comprehension, and short attention span
tests for visual perception
TVPS (test of visual perpetual skill)
MFVP (Motor free vision perception tests)
DTVP (development test of visual perception)
visual attention and processing skills
describes the ability to attend to a single object for sustained periods of time, as well as the ability to shift attention between multiple objects. Visual attention is closely tied to visual processing, which describes the ability to perceive and analyze an object to create an image of the object in the mind
4 main categories of VIP
visual spatial skills
visual analysis
visual attention and processing skills
visual motor integration skills
signs and symptoms of problems with visual attention and processing skills
easily distracted, slow reading speed, difficulty completing written assignments, difficulty attending to homework, and decreased reading comprehension
tests for visual attention and processing skills
symbol digit modalities
children’s color trials test
visual motor integration skills
visual motor integration describes the ability to use the visual processing information to direct fine motor movements (typically hand skills such as writing typing). visual motor integration involves visual analysis )receiving the characteristics of an object), visual conceptualization (reconstructing the image in the mind), and fine motor control (eye hand coordination)
signs and symptoms of visual motor integration skills
difficulty copying from the board during school, poor spacing of letters/words, significantly rotating the paper when writing, poor spelling when writing, and difficulty organizing mathematical columns of numbers
tests for visual motor integration skills
DTVM (Beery)
wold sentence copy test
test of visual motor skills
Piaget’s RL awareness test
assesses a child ability to distinguish R or L on himself and out in space. There are 5 subsections
A: show me your R and L hand
B: show me my R/ L, nad/leg
C: R vs left with coin and pencil
Jordan LR reversal test
determines how well children ages 5-18 can identify reversed images, letters, numbers, and sequences of letters (both in isolation and within text).
tests for visual spatial skills
Piagets
Jordans
tests for visual analysis skills
TVPS-3
MVPT-4
DTVP-3
Test of Visual Perceptual Skills (TVPS)
ages 4-18. It assess visual perceptual abilities without integrating motor abilities (motion is notrewuried to make a response). Items are presented in multiple choice format, and responses can be made vocally or by pointing to the answer choice format, and responses can be made vocally or by pointing to the answer choice. It contains 112 black and white designs (16 designs for each of the7 subsections). Each subset starts with 2, non scored examples, followed by 16 test items arranged in order of increasing difficulty
subsections of TVPS
visual discrimination visual memory spatial relationships form constancy sequential memory visual figure ground visual closure
Motor free visual perception test (MVPT)
assesses visual perceptual skills in children and adults ages 4-80. Contains 45 black and white dragons within 5 subsections. No copying or other motor skills are required to make a response. there are no ceilings for responses when scoring each subset
subsections of MVPT
spatial relationships visual discrimination figure ground visual closure visual memory
DTVP
assessment of visual perception and visual motor abilities
ages 4-12
subsets of DTVP
eye hand coordination copying figure ground visual closure form constancy
tests for visual motor integration
Beery (developmental test of visual motor integration)
Wold
TVMS
treatment of VIP deficits
involves in office and at home vision therapy. VT is aimed at improving the rate of visual information processing. Home therapy reinforces skill learned during office therapy, and should be performed 4-5days/week for 20-30m each session. Occupational therapists and teachers may also need to be involved
