Perception Flashcards
Vision Attention is influenced by:
-general alertness, visual fixation and focused gaze of person
Visual Attention is Defined as:
-person’s ability to determine “what” (object ID) and “where” (orientation to space) of things in the environment
Most common cause of perceptual impairments:
- Lesion to right hemisphere
- Left brain damage=deficit not as severe as right
Perceptual Impairment
- Loss of ability to correctly perceive
- distorted view of their body and awareness of their body in relation to environment
Causes of perception impairments:
- CVA
- TBI
- Degenerative disorders (MS, PD, Alzheimer’s)
Types of Perception Dysfunction
- Visual
- Body scheme
- Motor planing (praxis)
- Tactile
- Language (expressive/receptive)
Visual Perceptual Disorders
- Visual agnosia
- Prosopagnosia
Visual Agnosia
- inability to ID or recognize familiar objects and people (with visual system intact)
- Neural connections interrupted between cortical receptor region for visual stimulus and memory of image (parietal lobe damage)
Prosopagnosia
- client can’t ID familiar faces
- inability to perceive unique expressions of facial Mm that make us unique
Visual-Spatial Perceptual Disorders
- Right-Left Discrimination
- Difficulty following directions about how to get from one place to another and moving in new environments
Problems with Visual-Spatial Perceptual disorders
- -Topographical orientation
- -position in space dysfunction
- -depth perception
Body Scheme Perceptual Disorder
- (unilateral neglect syndrome)
- due to lesion/damage (CVA/TBI)
- problems with sense of body shape, position and capacity
- presents as inattention to side of body and environment
2 Subtypes of Unilateral Neglect
- Sensory neglect
- Motor neglect
Unilateral Neglect: Sensory Unawareness
–spatial, right/left, near/far space, observed in systems (tactile, visual, auditory)
Unilateral Neglect: Motor
-Hard to discriminated between sensory/motor
Anosognosia
- Extreme Neglect Syndrome
- Pt fails to recognize own limbs as their own (R hemisphere lesions)
- show strange affective dissociation (ask others to move limb)
- Typically resolves as pt recovers
Praxis
-ability to rapidly conceive of and plan motor acts in response to environment
Apraxia/Dyspraxia
- inability to carry out skilled movement in presence of intact sensation, movement and coordination
- disturbances in planning (conceptual/purpose) and execution (production/output)
- subtle or extremely obvious
Motor Perception disorders
- client has distorted perception of motor strategies needed to negotiate environment
- affects cognitive aspects of motor control
Functional Implications of Apraxia
- reduce ability to coordinate, plan and carry out movements of everyday tasks
- Difficulty performing series of steps
- -eating, shaving, opening doors, dressing
Conceptual Problems in Apraxia
- knowledge use of objects and tools for specific function
- knowledge of actions independent of object/tool to perform a function they serve
- knowledge of single actions needed within sequence
- selection of objects to perform action
Production Problems in Apraxia
- motor sequencing errors
- imitation and movement production
- object substitution and misuse
Assessment Methods for Apraxia
- consists of gesture production (ask pt to pantomime a task on command)
- assess sensory function, Mm strength and dexterity before testing for praxis
- assess visual agnosia prior to praxis testing
- eval language status
Apraxia and Aphasia
- apraxia often occurs with aphasia (makes it hard to distinguish the two)
- pts with aphasia–have expressive and receptive deficits
- check for comprehension
Ideational Apraxia
- inability to cognitively understand the motor demands of a task involving multiple or sequential steps (disruption in conception rather than execution)
- lack of knowledge regarding tool and object use
- may have difficulty sequencing of activity steps or use of objects in relation to each other
Clinical Observations in Ideational Apraxia
- use familiar objects incorrectly
- -eat soap, chew washcloth, move wheelchair by pulling armrests
- -multistep tasks
- -stir drink with finger, brush teeth with finger
- slow task or doesn’t do at all
Ideomotor Apraxia
- difficulty with production errors (motor apraxia) even though idea and purpose is intact
- -OR–
- motor plan intact but pt can’t access appropriate plan or uses inappropriate motor plan for task
e.g. understands toothbrush is for brushing teeth but uses it to brush hair
With ideomotor apraxia: sometimes pt can’t access specific motor plan on command but______
-can when presented with visual cue (such as comb to comb hair)
Observations of Ideomotor Apraxia
- awkward/clumsy movements
- hard to plan movements to cross body’s midline
- hard to orient hand to conform to objects
- hard to sequence movements
- delayed initiation
Dressing Apraxia
-inability to dress self
Constructional Apraxia
-inability to organize or assemble parts into a whole
(copying, drawing, building 2/3D designs)
-Specific deficit in spatial organization performance
–Functional: setting table, make sandwich, dishes into dishwasher
Tactile Perception Impairment
- Tactile agnosia
- Astereognosis
Tactile Agnosia
-inability to attach meaning to somatosensory information
Astereognosis
-inability to ID objects by touch
Stereognosis Testing
- ID familiar objects by hand with eyes closed
- (pencil, key, nail, safety pin, paperclip)
Perception Intervention
- provide physical contact
- repeated practice on tasks and environments, gradually fade support
- perform familiar tasks
- mental practice/visualize task/sequence
Intervention For Motor Planning
- draw attention to features of object/activity
- use written lists/visuals as reminders
- tool use
- training to caregivers
- safety issues
