(A) Visual Perception Flashcards
what is visual perception
receivng information from env through sensory impulses and converting it into meaningful information
what is visual acuity? give an example
clarity/shaprness of vision
ability to recognize shape/details of object from distance
- color vision, peripheral vision, visual field
ex: seeing traffic light
what categorie of visual perception does hemianopsia affect?
visual acuity bc can only see half the visual field
what is visual discrimination. give an example
ability to see subtle differences and similatirits between shape/objects
ex: foreign coins
what is visual figure? give ex
ability to focus on one object in busy background
ex: keys in messy drawer
what is visual closure?
ability to crrectly perceive object/work even when it is partly hidden
ex: road sign w snow
what is visual memory/pattern recognition?
ability to recall or remember visual details of what you have seen
ex: reading, recognize letter
what is visual sequential memory
ability to remember visual details in correct sequence
ex: writing (to remmeber sequence of letters to spell word)
what is visual form constancy
ability to rec and label objects even when they are viewed from different angle or in a different environment
ex: recognize dog in photo vs recognize dog whilst its running
what is visual spatial relationship?
abilityt to perceive relationships of objects posiiton in space
ex: reading map, bump into things
what cateogie is affected in usn?
visual spatial relationship (visual acuity is perfect)
what is visual motor integration?
ability to interpret visual info and respond with motor action
ex: catch ball
what is visual agnosia
ability to reco or describe use of familiar visual objects (normal visual function
ex: cannot recognize cellphone but can can identify by touch or sounds
what is unilateral spatial neglect (USN)
feature of stroke defined as failure to attent to the side opposite of brain lesion
what are the 3 categories of USN. describe each one of them
- sensory neglect (input issues): impaired ability to perceive object => do not attend to visual, auditory, or sensory stimuli on affected side = USN
- motor neglect (integration and output issue): reduced ability to initiate movement in resopnse to stimuli on affected side despite awareness of stimuli (not explained by motor weakness of lack of sensitivity)
- representational neglect: failure to describe affected side of a familiar scene from memory (Not explained by memory loss)
what is anosagnosia?
lack of insight regarding their failure to attend to side opposed of brain lesion ie not aware of USN
how does USN differ from hemianopsia?
- hemianopsia = primary sensory loss so aware ur not receiving visual input so u can quickly compensate
- usn = neglect, disorganized, disrupted search strated => cant scan bc border between neglected space and non neglected space is not sharp nor absolute (no vertical mjidline)
what are the 3 hemispaces of usn?
- personal space = on their own body
- near extrapersonal space (peripersonal) = within their reach (ex: eating, reading)
- far extrapersonal space = beyonf reaching point (walking)
what screening must be done within 48 h of a patient w stroke regaining consciousness?
cogntiive (ex: moca) for screeen which can be complimented w ax such as motor free visual perception test
what is the motor free visual perception test (MVPT-3). what are its domains, its population
AX:
domain: visual perception, independent motor ability for ind w storke, head injury, peds, others
what is the behavioral inattention test: domain, population
assessment of USN (presence, extent) using everyday activities w patients w stroke
- asked to cross line, cancel letter, cancel star…
- patient required communciation
what type of tx appoach should be used for USN?
a mixture of remedial, compensatory, task oriented
what is the best strategy for tx interventions for USN?
education
=> include cognitive strategy for compensation such to increase visual search strategies
=> get client to understand that their vision cannot be trusted on affected side => to develop intellectual override
name compensatory strategies used for USN (4)
- adequate lighting
- increase visibility of task/environment (reduce background pattern and increase constrat)
- organize structure environment
- simplify task
