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
