Visual Perception Assessment “The mind can only see what it is prepared to see” - Edward de Bono OCT 1172: Neuroanatomy Tuesday, February 1 st, 2005 Nadia

Visual Perception AssessmentVisual Perception Assessment

““The mind can only see what it is prepared to see”The mind can only see what it is prepared to see” - Edward de Bono- Edward de Bono

OCT 1172: NeuroanatomyTuesday, February 1st, 2005

Nadia Abdel-HafezLisa Purdy

Vivien Chan

AgendaAgendaOverview of visual perceptionOverview of visual perception

TheoryTheory

Summary of:Summary of:LOTCALOTCAMotor-Free Visual Perception TestMotor-Free Visual Perception TestRivermead Perceptual Assessment BatteryRivermead Perceptual Assessment BatteryOSOT Perceptual EvaluationOSOT Perceptual Evaluation

Application to occupational performance of meal Application to occupational performance of meal preparation and drivingpreparation and driving

What is Visual Perception?What is Visual Perception?

PerceptionPerception ““the dynamic process of receiving the environment through sensory the dynamic process of receiving the environment through sensory

impulses & translating those impulses into meaning based on a impulses & translating those impulses into meaning based on a previously developed understanding of that environment.”previously developed understanding of that environment.”

(Bouska et al., 1990; Grieve, 1993; Arnadottier, 1990)(Bouska et al., 1990; Grieve, 1993; Arnadottier, 1990)

VisualVisual PerceptionPerception ““ability to identify, organize, interpret and comprehend visual ability to identify, organize, interpret and comprehend visual

information received by a person through his or her eyes” information received by a person through his or her eyes”

(Hammill et al, 1993)(Hammill et al, 1993)

How does visual processing occur?How does visual processing occur?~ ~ Frame of ReferenceFrame of Reference ~ ~

Bottom-Up ProcessingBottom-Up ProcessingPrimary perceptual processes modify sensation into perceptionPrimary perceptual processes modify sensation into perception

Environment drivenEnvironment driven– ExampleExample

Sensation = vision, perception = form, colour, movementSensation = vision, perception = form, colour, movement

Top-Down ProcessingTop-Down ProcessingLearned experience of perceptions decrease number of possible Learned experience of perceptions decrease number of possible interpretations of sensory environmentinterpretations of sensory environment

Driven by knowledge setDriven by knowledge set– ExampleExample

Opitical illusions when told what to look forOpitical illusions when told what to look for

Zolton, 1996

Optical IllusionOptical Illusion

Luria’s Functional Systems Model :Luria’s Functional Systems Model :Perceptual Process Perceptual Process

The CNS interprets Information in three stages: The CNS interprets Information in three stages:

1.1. Nervous System registers stimulus eventNervous System registers stimulus eventLuria’s first functional unitLuria’s first functional unit

2. System interprets and organizes sensory information2. System interprets and organizes sensory informationLuria’s second functional unitLuria’s second functional unit

3. System compares stimulus to past experience and relates stimulus 3. System compares stimulus to past experience and relates stimulus to goal.to goal.Luria’s third functional unitLuria’s third functional unit

All three stages work together and failure can occur at any stage. All three stages work together and failure can occur at any stage. Abreu & Toglia, 1987Abreu & Toglia, 1987

Second Functional Unit

Posterior CortexSensation & Perception

First Functional Unit

Brain StemArousal & Activation

Third Functional Unit

Frontal LobeProgramming & Regulating

Primary Area Zone

Basic sensory InformationIe. light and angle sensations

Secondary Area Zone

Turning sensations into perceptionsUnimodal

Difficulties with this zone = Agnosia

Ie. Light sensation is perceived as an object .

Tertiary Area Zone

Integration of all sensationsPoly modal

Integration of all sensations Ie. watching your favorite

T.V. show favorite

Luria’ s Functional Systems

A process of perception

Why Assess Visual Perception?Why Assess Visual Perception?Mental Status examinations rely heavily on verbal skills Mental Status examinations rely heavily on verbal skills which may not detect subtle cognitive impairments, which may not detect subtle cognitive impairments, which vision perception tests could identify. which vision perception tests could identify.

Golisz, K., Toglia, J.,Golisz, K., Toglia, J.,

Cause of continued confusion and lack of rehabilitation Cause of continued confusion and lack of rehabilitation progress despite return of motor functionprogress despite return of motor function

Zolton, 1996Zolton, 1996

May contribute to inability to perform desired May contribute to inability to perform desired occupations as well as occupations that are needed occupations as well as occupations that are needed and/or expectedand/or expected

Visual PerceptionVisual PerceptionBarbara Zolton organizes components of Barbara Zolton organizes components of visual perception into 3 catagories:visual perception into 3 catagories:

1.1. Visual ProcessingVisual ProcessingRegistration of visual input through ocularmotor control, visual Registration of visual input through ocularmotor control, visual fields, and acuityfields, and acuity

2.2. Visual DiscriminationVisual Discrimination

3.3. Body SchemaBody SchemaRepresentation of spatial relations among parts of bodyRepresentation of spatial relations among parts of body

LOTCALOTCATMTM Battery Battery Loewenstein Occupational Therapy Cognitive AssessmentLoewenstein Occupational Therapy Cognitive Assessment

Authors:Authors:Malka Itzkovich, Betty Elazar, Sarah Averbach Malka Itzkovich, Betty Elazar, Sarah Averbach

Developed in 1974, at Developed in 1974, at the Loewenstein the Loewenstein Rehabilitation Hospital in Rehabilitation Hospital in IsraelIsrael

LOTCA: PurposeLOTCA: Purpose

Determine client’s abilities and limitations in Determine client’s abilities and limitations in cognitive functioningcognitive functioning

Guides interventionGuides intervention

Examines clinical changeExamines clinical change

Screening tool for further assessmentScreening tool for further assessment(Katz, Itzovich, Averbuch & Elazar, (Katz, Itzovich, Averbuch & Elazar,

1988)1988)

LOTCA: PopulationLOTCA: Population

Developed to assess patients with brain-injuriesDeveloped to assess patients with brain-injuries

Validated to assess those 6 years and upValidated to assess those 6 years and up

Lowenstein Occupational Therapy Cognitive Lowenstein Occupational Therapy Cognitive Assessment-Geriatric (LOTCA-G) is also Assessment-Geriatric (LOTCA-G) is also available available

LOTCA: DomainsLOTCA: Domains

20 subtests 20 subtests

Four DomainsFour Domains::

1. Orientation1. Orientation

2. Perception 2. Perception

3. Visuomotor 3. Visuomotor organizationorganization

4. Thinking Operations4. Thinking Operations

LOTCA: ApproachLOTCA: Approach

Derived from:Derived from:authors’ clinical experiencesauthors’ clinical experiences

Luria’s neuropsychological model Luria’s neuropsychological model

Piaget’s developmental model.Piaget’s developmental model.

Derivative of the Luria-Nebraska Derivative of the Luria-Nebraska Neuropsychological Battery (LNNB) Neuropsychological Battery (LNNB)

Bottom Up assessmentBottom Up assessment

Luria: A Continuum of PerceptionLuria: A Continuum of Perception

According to Abreu, 1985:According to Abreu, 1985:There are 6 areas critical for assessment: There are 6 areas critical for assessment: 1.1. OrientationOrientation2.2. AttentionAttention3.3. Motor PlanningMotor Planning4.4. Visual ProcessingVisual Processing5.5. CognitionCognition6.6. Occupational BehaviourOccupational Behaviour

LOTCA’s domains are congruent with this LOTCA’s domains are congruent with this theory.theory.

Piaget’s Theory of Cognitive Piaget’s Theory of Cognitive Developmental ModelDevelopmental Model

Age-level standards were developed by testing Age-level standards were developed by testing 240 healthy children (ages 6-12) for the 240 healthy children (ages 6-12) for the determination:determination:

1.1. Hierarchical orderHierarchical order of acquiring the cognitive of acquiring the cognitive competencies included in test.competencies included in test.

2.2. Age normsAge norms for subtests for subtests

Developmental curves provided in manualDevelopmental curves provided in manual(Averbach, 1989)(Averbach, 1989)

LOTCA:LOTCA:Subtests 1 & 2: OrientationSubtests 1 & 2: Orientation

Client is asked questions concerning :Client is asked questions concerning :

TimeTime ““what day is today?”what day is today?”

PlacePlace ““Name a city that is located near your home address”Name a city that is located near your home address”

Orientation deficits are frequent symptoms of Orientation deficits are frequent symptoms of brain injuries. However, good orientation is not brain injuries. However, good orientation is not evidence of cognitive competenceevidence of cognitive competence

(Lezak, 1983)(Lezak, 1983)

LOTCA: LOTCA: Perception Perception

Six subtests:Six subtests:

3.3. Visual Identification of ObjectsVisual Identification of Objects

4.4. Visual Identification of ShapesVisual Identification of Shapes

5.5. Overlapping FiguresOverlapping Figures

6.6. Object Constancy Object Constancy

7.7. Spatial PerceptionSpatial Perception

8.8. PraxisPraxis

Subtest 3: Visual Identification of Subtest 3: Visual Identification of ObjectsObjects

8 everyday objects8 everyday objects:: chair, teapot, watch, shoe, bicycle, key, scissors, chair, teapot, watch, shoe, bicycle, key, scissors, glasses are illustrated and presented to clientglasses are illustrated and presented to client

Client is expected to name the objects correctlyClient is expected to name the objects correctly

What do you see?What do you see?

Clients with Expressive ProblemsClients with Expressive Problems

To rule out or control for anomia aphasia, the To rule out or control for anomia aphasia, the clinician shows the client two boards with four clinician shows the client two boards with four objects presented on each. objects presented on each.

Ask questions such as “Where is the chair?”Ask questions such as “Where is the chair?”

What if you still could not see it?What if you still could not see it?

Visual Identification of ObjectsVisual Identification of Objects

If the client is unable to locate the 8 objects or If the client is unable to locate the 8 objects or has has receptive aphasiareceptive aphasia,, the therapist shows the therapist shows two boards with two boards with similarsimilar objects on each and objects on each and the patient must match the target object on the patient must match the target object on the board. the board.

If unable to complete that, the patient is If unable to complete that, the patient is shown two boards with shown two boards with identical identical objects and objects and the patient can perform exact matching. the patient can perform exact matching.

Subtest 4: Visual Identification of Subtest 4: Visual Identification of ShapesShapes

Patient is asked to identify 8 different shapes:Patient is asked to identify 8 different shapes: square, triangle, circle, rectangle, diamond, semi-circle, square, triangle, circle, rectangle, diamond, semi-circle, trapezoid, hexagontrapezoid, hexagon. .

Two levels of difficulty Two levels of difficulty

If the client has expressive problems, they will be shown a If the client has expressive problems, they will be shown a

board with identical shapes.board with identical shapes.

Detecting the Presence of Visual Detecting the Presence of Visual AgnosiaAgnosia

Associative agnosiaAssociative agnosia::unable to recognize the meaning of objects of what unable to recognize the meaning of objects of what is being perceivedis being perceived

The ability to see this object is intact, however, is The ability to see this object is intact, however, is not able to connect object with its meaningnot able to connect object with its meaning

Able to copy and matchAble to copy and match

Detecting the Presence of Visual Detecting the Presence of Visual AgnosiaAgnosia

Aperceptive agnosiaAperceptive agnosia:: inability to visually perceive the object, inability to visually perceive the object, therefore, unable to name the object therefore, unable to name the object

Although, sensation and meaning are intact, there is a Although, sensation and meaning are intact, there is a failure with visual perceptionfailure with visual perception

Client will not be able to match and assessment will stop Client will not be able to match and assessment will stop

here if discoveredhere if discovered

What is the LOTCA Missing?What is the LOTCA Missing?

Other types of Agnosia’s are not assessed Other types of Agnosia’s are not assessed within the LOTCA…within the LOTCA…

ProsopagnosiaProsopagnosia

Also called: Also called: associative associative and and aperceptive face aperceptive face agnosiaagnosia

The inability to recognize an individual that is The inability to recognize an individual that is known to the clientknown to the client

The client understands that he is looking at a The client understands that he is looking at a face but cannot say to whom the face belongsface but cannot say to whom the face belongs

(Zolton)(Zolton)

Colour agnosiaColour agnosia

Inability to recognize coloursInability to recognize colours

The patient cannot identify the colour the word is The patient cannot identify the colour the word is written inwritten in

Diagrams in LOTCA are Black and WhiteDiagrams in LOTCA are Black and White

Subtest 5: Overlapping FiguresSubtest 5: Overlapping Figures

The evaluator shows the client two cards with The evaluator shows the client two cards with three overlapping objects.three overlapping objects.

Asks “what is drawn on the card?”Asks “what is drawn on the card?”

Subtest 5: Overlapping FiguresSubtest 5: Overlapping Figures

This subtest assesses: This subtest assesses:

Figure Ground Perception:Figure Ground Perception:

The ability to distinguish foreground from The ability to distinguish foreground from background. (Zoltan, 1996)background. (Zoltan, 1996)

Subtest 6: Object ConstancySubtest 6: Object ConstancyThe clinician shows the patient four photographs The clinician shows the patient four photographs of objects taken from unusual anglesof objects taken from unusual angles

Asks patient “What do you see in the Asks patient “What do you see in the photograph?”photograph?”

Subtest 6: Object ConstancySubtest 6: Object Constancy

If If language difficulties are present, the clinician language difficulties are present, the clinician can use a multiple choice boardcan use a multiple choice board

Subtest 6: Object ConstancySubtest 6: Object Constancy

Form DiscriminationForm Discrimination: : The inability to distinguish between objects that are The inability to distinguish between objects that are similar in formsimilar in form

Colour, orientation, edge, and motion cues are all utilized Colour, orientation, edge, and motion cues are all utilized for form discriminationfor form discrimination

Eg. difference between a “p” or “b” when readingEg. difference between a “p” or “b” when reading

Subtest 7: Spatial PerceptionSubtest 7: Spatial Perception

Patient is asked to discriminate Patient is asked to discriminate betweenbetween

Right and left on himselfRight and left on himself

Two objects: pencil and boxTwo objects: pencil and box

Right and left of the therapistRight and left of the therapist

Subtest 7: Spatial Perception Subtest 7: Spatial Perception

This subtest assesses for This subtest assesses for Body Schema Body Schema DisordersDisorders::

Right/left discrimination-Right/left discrimination- inability to tell left inability to tell left from rightfrom right

SomatognosiaSomatognosia – lack of awareness of body – lack of awareness of body structure and inability to recognize and structure and inability to recognize and reference one’s body partsreference one’s body parts

LOTCA: Remaining AreasLOTCA: Remaining Areas

Visual Motor Organization Visual Motor Organization

Thinking Operations Thinking Operations

These are concerned These are concerned Higher Level PerceptionHigher Level Perception. . Involves Construction Tasks Involves Construction Tasks

Executive FunctioningExecutive Functioning

LOTCA: ScoringLOTCA: Scoring

Each subtest is scored on a 4-5 point scaleEach subtest is scored on a 4-5 point scale

4 areas of LOTCA:4 areas of LOTCA:1. Orientation (max=8)1. Orientation (max=8)2. Perception (max=20)2. Perception (max=20)3. Visuomotor organization (max=28)3. Visuomotor organization (max=28)4. Thinking operations (max=23)4. Thinking operations (max=23)

AttentionAttention and and concentrationconcentration is observed by therapist and is scored. Time is observed by therapist and is scored. Time is recorded. is recorded.

Each area can be interpreted separatelyEach area can be interpreted separately

Aids in treatment planning and intervention Aids in treatment planning and intervention

(Katz, 2002)(Katz, 2002)

LOTCA: PsychometricsLOTCA: Psychometrics

Psychometrically SoundPsychometrically SoundMany studies have validated the testMany studies have validated the test

– Refer to Psychometric Chart in HandoutRefer to Psychometric Chart in Handout

HighlightsHighlights– Can Can differentiatedifferentiate performance levels as well as performance levels as well as

between patterns of cognitive deficits related to the site between patterns of cognitive deficits related to the site of brain lesions (Katz et al, 1988).of brain lesions (Katz et al, 1988).

– Predictive and Ecological ValidityPredictive and Ecological Validity with occupational with occupational performance in ADLs performance in ADLs

(Katz et al, 2000)(Katz et al, 2000)

LOTCA: Clinical UtilityLOTCA: Clinical Utility

Client acceptability Client acceptability

Includes procedures for aphasic patientsIncludes procedures for aphasic patients

Widely used and favored by occupational Widely used and favored by occupational therapists therapists

Time:Time: 30-45 minutes, can be divided into 2-3 sessions if 30-45 minutes, can be divided into 2-3 sessions if requiredrequired

LOTCA: CritiqueLOTCA: Critique

LOTCA’ s approach of cognition-perception LOTCA’ s approach of cognition-perception assessment adheres to the criteria set forth assessment adheres to the criteria set forth by Abreu and Tonglia by Abreu and Tonglia ((based on Luria’s theory)based on Luria’s theory)

Hierarchical arrangement of tasksHierarchical arrangement of tasks

Flexible assessment e.g. Flexible assessment e.g. Multi-choice format if neededMulti-choice format if needed

Can observe the patient’s strategies in the Can observe the patient’s strategies in the visuomotor tasks. visuomotor tasks.

Suggestions/CritiqueSuggestions/Critique

Inclusion of occupational behaviour is Inclusion of occupational behaviour is questionablequestionable

Suggestions Suggestions Vertical Placement of Diagrams to accommodate those Vertical Placement of Diagrams to accommodate those with unilateral spatial neglect, as it could be a with unilateral spatial neglect, as it could be a confounding factor. LOTCA relies heavily on confounding factor. LOTCA relies heavily on visual/spatial abilities visual/spatial abilities

(Katz et al, 2000)(Katz et al, 2000)Manual should have clearer definitions of constructs Manual should have clearer definitions of constructs

Motor-Free Visual Perception Test Motor-Free Visual Perception Test (MVPT)(MVPT)

Authors:Authors:Ronald P. Colarusso Ronald P. Colarusso

and Donald D. Hammill (1972)and Donald D. Hammill (1972)

MVPT PurposeMVPT Purpose

DescriptiveDescriptive

Measures visual perception without the variable Measures visual perception without the variable of motor involvement of motor involvement

Practical for screening, diagnostic and research Practical for screening, diagnostic and research purposespurposes

(Brown et al., 2003)(Brown et al., 2003)

Rationale behind “Motor Free”Rationale behind “Motor Free”

Motor free assessment of visual perceptionMotor free assessment of visual perception

Colarusso and Hammill (1996) Colarusso and Hammill (1996) although motor and visual skills are often clearly associated, they can although motor and visual skills are often clearly associated, they can also be very separate abilitiesalso be very separate abilities

Authors claim many tests of visual perception require Authors claim many tests of visual perception require complicated graphic responses complicated graphic responses

drawing introduces confounding variable of motor drawing introduces confounding variable of motor

No clear rationale provided in manual as to why a motor No clear rationale provided in manual as to why a motor free test of visual perception is desirable free test of visual perception is desirable


MVPT ApproachMVPT Approach

Bottom up assessmentBottom up assessment

36 items, multiple choice format36 items, multiple choice format

Inanimate pictures, black and whiteInanimate pictures, black and white

No time limitNo time limit

MVPT DomainsMVPT Domains

Chalfant and Scheffelin (1969):Chalfant and Scheffelin (1969):

1. 1. Visual discriminationVisual discrimination

2. 2. Visual figure ground theoryVisual figure ground theory

3. 3. Visual memoryVisual memory 4. 4. Visual closureVisual closure

5. 5. Visual spatial relationshipsVisual spatial relationships


MVPT AdministrationMVPT Administration

Administrator presents item to client, points to Administrator presents item to client, points to stimulus figure while verbalizing “look at this”stimulus figure while verbalizing “look at this”

Administrator points at 4 alternatives, while Administrator points at 4 alternatives, while verbalizing “find it here”verbalizing “find it here”

Client points to one of four alternatives if Client points to one of four alternatives if cannot verbalize responsecannot verbalize response

Administrator confirms clients responseAdministrator confirms clients response

1. Visual Discrimination1. Visual Discriminationability to discriminate dominant features in different objectsability to discriminate dominant features in different objects

2.Visual Figure Ground Theory2.Visual Figure Ground Theoryability to distinguish an object from its backgroundability to distinguish an object from its background

3.Visual Memory3.Visual Memoryability to recall dominant features of one stimulus item or to ability to recall dominant features of one stimulus item or to

remember the sequence of several itemsremember the sequence of several items

Do you remember…Do you remember…

4. Visual Closure4. Visual Closureability to identify incomplete figures when only ability to identify incomplete figures when only

fragments are presentedfragments are presented

5.Visual Spatial Relationships5.Visual Spatial Relationshipsability to orient one’s body in space and to perceive ability to orient one’s body in space and to perceive

the positions of objects in relation to oneself and to the positions of objects in relation to oneself and to objectsobjects

MVPT PopulationMVPT Population

Original MVPTOriginal MVPT- Colarusso and Hammill (1972)Colarusso and Hammill (1972)- standardized on 881 “normal” American children 4-8 years old, residing in standardized on 881 “normal” American children 4-8 years old, residing in

22 states22 states- despite limited age range of normative data, MVPT used on children and despite limited age range of normative data, MVPT used on children and

adults due to good clinical utility adults due to good clinical utility (Brown et al., 2003)(Brown et al., 2003)

MVPT RevisedMVPT Revised- Bouska and Kwatny (1983)Bouska and Kwatny (1983)- original version revised and adapted for use with adult population original version revised and adapted for use with adult population - original MVPT administered to 32 patients with brain damage- original MVPT administered to 32 patients with brain damage- analysis of data used in development of revision of original testanalysis of data used in development of revision of original test (Bouska and Kwatny, 1983)(Bouska and Kwatny, 1983)

Additional Versions of MVPTAdditional Versions of MVPT

MVPT RevisedMVPT RevisedColarusso and Hammill, 1993Colarusso and Hammill, 1993

addressed issues of outdated and incomplete normative dataaddressed issues of outdated and incomplete normative datarevised normative data collected on 912 children in Georgia and revised normative data collected on 912 children in Georgia and Northern CaliforniaNorthern Californiano psychometric studies completed on MVPT-Rno psychometric studies completed on MVPT-R

(Brown et al, 2003)(Brown et al, 2003)

MVPT VerticalMVPT VerticalTo eliminate effect of unilateral neglect, items presented vertically, as opposed to horizontallyGeared towards people 50 years and older

(Mercier et al., 2001)(Mercier et al., 2001)

ScoringScoring

One raw overall score attained One raw overall score attained Usefulness of scoring method questionable Usefulness of scoring method questionable

Volpe-Johnstone (2001) Volpe-Johnstone (2001) too few items in some of the groupings to be able to make definitive too few items in some of the groupings to be able to make definitive statements regarding the domainsstatements regarding the domains

Abreu and Toglia (1987)Abreu and Toglia (1987)Dichotomous scores alone reveal little about the person’s functioning and Dichotomous scores alone reveal little about the person’s functioning and should be eliminated should be eliminated

guessing, inattention, perseveration and other brain-damage guessing, inattention, perseveration and other brain-damage variables can affect scorevariables can affect score

Clinical Utility & PsychometricsClinical Utility & Psychometrics

Different versions available, enhances applicabilityDifferent versions available, enhances applicability

Quick: 10 – 20 minutesQuick: 10 – 20 minutes

Standardized: easy to administer and scoreStandardized: easy to administer and score

Acceptability questionableAcceptability questionable

Multi disciplinaryMulti disciplinary

Excellent validity and reliability Excellent validity and reliability

(test-retest)(test-retest)Refer to handout Refer to handout

Suggestions/CritiqueSuggestions/Critique

Difficulty in interpreting resultsDifficulty in interpreting resultsDichotomous scoringDichotomous scoring

(Brown et al, (Brown et al, 2003)2003)

Limited in intervention planningLimited in intervention planningFor predictive purposes, use in conjunction with ADL assessmentFor predictive purposes, use in conjunction with ADL assessment

Generalizability of MVPT questionableGeneralizability of MVPT questionableClients’ who perform well on tests that assess visual processing of Clients’ who perform well on tests that assess visual processing of inanimate objects (as does MVPT), often perform poorly on tests inanimate objects (as does MVPT), often perform poorly on tests that assess animate objects that assess animate objects

(Duchaine et al., (Duchaine et al., 2003)2003)

Rivermead Perceptual Assessment Rivermead Perceptual Assessment

BatteryBattery

Authors:Authors:S. Whiting S. Whiting

N. LincolnN. Lincoln

G. Bhavnani G. Bhavnani

J. CockburnJ. Cockburn

International Availability: International Availability: Available worldwide Available worldwide

Rivermead, 1985Rivermead, 1985

PurposePurpose:: – 16 subtests, screen for visual and spatial

perception– Evaluative, descriptive,Evaluative, descriptive,

PsychometricsPsychometrics:: – mixed results for predictablity (Donnelly, 2002)mixed results for predictablity (Donnelly, 2002)

Clinical Utility:Clinical Utility:– No special training required, easy to administerNo special training required, easy to administer– Standardized, with norms for ages 16-97Standardized, with norms for ages 16-97

16 subtests assess within the following areas:

Picture Matching Object Matching

Size Recognition Series

Missing Article Sequencing-Pictures

Right/Left Copying Words Colour Matching

Right/Left Copying Shapes Cube Copying

Three-Dimensional Copying Cancellation

Figure-Ground Discrimination Animal Halves

Body-Image Self-Identification Body Image

Reading Test

Rivermead Perceptual Assessment Battery (RPAB)

(Whiting, Lincoln, Bhavnani, & Cockburn, 1985)

Critique:- Comprehensive, time consuming, and uses child-like material; - Need to increase difficulty level to avoid ceiling effect for patients less severely impaired

(Chwen-Yng et al, 2000)

O.S.O.T. Perceptual EvaluationMarion Boys, Pat Fisher, and Claire Holzberg

Ontario Society of Occupational Therapists, 1991

Purpose:– Detection of perceptual impairment in adults using 18 tests– Descriptive (screening tool), evaluative

Psychometrics:– high inter-rater reliability, established validity

Clinical Utility:Population: patients with brain injuryOldest, popular (especially in stroke setting)Standardized: Very quick and easy to useCancellation Sheets and the Score Sheets (copyright free)

Meal PreparationMeal PreparationLOTCALOTCATMTM Battery Battery

Visual Identification of ObjectsVisual Identification of ObjectsAgnosiaAgnosia

unable to find/recognize any items used in unable to find/recognize any items used in meal prep (groceries, utensils, pots/pans) meal prep (groceries, utensils, pots/pans) unless use other sensesunless use other senses

can use touch to identify objects, but safety can use touch to identify objects, but safety issue (knife, stove) issue (knife, stove)


Visual Identification of ShapesVisual Identification of Shapes

Aperceptive AgnosiaAperceptive Agnosiaunable to “see” object (cannot describe, match, copy or unable to “see” object (cannot describe, match, copy or discriminate from another object)discriminate from another object)

will not be able to differentiate between shapes of items needed will not be able to differentiate between shapes of items needed for cookingfor cooking

Cannot tell the difference between a spoon and a knifeCannot tell the difference between a spoon and a knife

May reach for a round pizza pan instead of a rectangular cookie May reach for a round pizza pan instead of a rectangular cookie sheetsheet

Meal PreparationMeal PreparationVisual Identification of Shapes – Cont’dVisual Identification of Shapes – Cont’d

Associative AgnosiaAssociative AgnosiaWould be able to describe difference between a fork and spoon, but Would be able to describe difference between a fork and spoon, but not understand the meaning in difference between a fork and spoonnot understand the meaning in difference between a fork and spoon

could describe steam coming off a hot pot, but will not know it is steam could describe steam coming off a hot pot, but will not know it is steam or understand that it is hot and may therefore reach through it instead or understand that it is hot and may therefore reach through it instead around it to turn off stove.around it to turn off stove.

cannot read recipes as letters have no meaning and cannot be cannot read recipes as letters have no meaning and cannot be interpreted by another sense (unless raised like brail) other than interpreted by another sense (unless raised like brail) other than audition (have someone read audition (have someone read

directions to them,directions to them,

tape recorded recipes)tape recorded recipes)


Overlapping FiguresOverlapping Figures

trying to pick out utensils from a trying to pick out utensils from a messy drawer, could use touch, but messy drawer, could use touch, but

safety issuesafety issue

Messy spice cabinet, must sort Messy spice cabinet, must sort though spice bottles to find the one though spice bottles to find the one you wantyou want

Washing dishes in sink, could not Washing dishes in sink, could not see the plate underneath the pan in see the plate underneath the pan in the sinkthe sink


Object ConstancyObject Constancy

Stacked pots and pansStacked pots and pansMay not be able to recognize the pot May not be able to recognize the pot because of different view when stackedbecause of different view when stacked

May not be able to pick out produce from May not be able to pick out produce from fridgefridge

Eg. Tomato cut in half, may not recognize that it is a Eg. Tomato cut in half, may not recognize that it is a tomato because seeing it from a different view tomato because seeing it from a different view

(inside now exposed instead of (inside now exposed instead of seeing a perfectly seeing a perfectly

round tomato)round tomato)


Spatial PerceptionSpatial PerceptionVisual Spatial AgnosiaVisual Spatial Agnosia

StereopsisStereopsis would have difficulty pouring a liquid into a glass or pot, would have difficulty pouring a liquid into a glass or pot,

judgment of fullness impaired therefore = overfill judgment of fullness impaired therefore = overfill

Difficulty judging distances Difficulty judging distances May try to place something on counter-top, May try to place something on counter-top,

undershoot and drop it on the ground, undershoot and drop it on the ground, OROR

may knock things over (overshoot)may knock things over (overshoot)

NOTE:The LOTCA does not directly assess depth perception, does so Indirectly though visuomotor subtests

Driving AbilityDriving AbilityMotor-Free Visual Perceptual TestMotor-Free Visual Perceptual Test

“…“…90% of informational input to the driver is visual.”90% of informational input to the driver is visual.”

“…“…visual perceptual skills such as scanning, tracking & figure ground visual perceptual skills such as scanning, tracking & figure ground discrimination determine the ability to notice and react to objects in the discrimination determine the ability to notice and react to objects in the visual field.” visual field.”

Poor performance on the MVPT was found to be highly predictive of Poor performance on the MVPT was found to be highly predictive of failure on the on-road driving test, but was not highly predictive of a failure on the on-road driving test, but was not highly predictive of a passpass

Those with a score of Those with a score of 30 were 8.7x’s more likely to fail, than those with 30 were 8.7x’s more likely to fail, than those with scores scores 3030

Even at the highest scores, half the subjects passed while the other half Even at the highest scores, half the subjects passed while the other half failedfailed

Mazer, Korner-Bitendsky & Sofer, 1998


Visual DiscriminationVisual Discrimination

Shape:Shape: could not distinguish an object by shape (eg. Stop sign is an octagon), could could not distinguish an object by shape (eg. Stop sign is an octagon), could

not read road signs (“ambulance” in rear-view mirror), what about traffic lights not read road signs (“ambulance” in rear-view mirror), what about traffic lights that have extra arrows? that have extra arrows?

Form:Form: What is this? Can you recognize the major What is this? Can you recognize the major

distinguishing features of this object?distinguishing features of this object?

Colour Agnosia: Colour Agnosia: traffic lights, especially when not in ONTtraffic lights, especially when not in ONT

Eg. Lights are vertical in ONT so know order of lights, but if drive into Eg. Lights are vertical in ONT so know order of lights, but if drive into Quebec, lights are horizontal, and would not be able to distinguish Quebec, lights are horizontal, and would not be able to distinguish between red, yellow, and greenbetween red, yellow, and green

Note: MVPT does not test for colour discrimination and limited testing for letter discimination


Visual Figure GroundVisual Figure Ground

Can you find the traffic Can you find the traffic lights from the competing lights from the competing background?background?

When approaching an When approaching an intersection, you look for intersection, you look for traffic lights to guide your nexttraffic lights to guide your nextmove (stop or go).move (stop or go).

Driving behind a car, can you Driving behind a car, can you distinguish the break lights from distinguish the break lights from the other features of the the other features of the vehicle?vehicle?How about when it is snowing?How about when it is snowing?


Visual MemoryVisual MemoryChanging lanes:Changing lanes:

– Must look in mirrors and check blind spot and remember where the Must look in mirrors and check blind spot and remember where the cars are to change lanescars are to change lanes

When driving in rain or snow, lose vision for a brief moment as the When driving in rain or snow, lose vision for a brief moment as the wipers clear the windshieldwipers clear the windshield

– Need to remember what was ahead of youNeed to remember what was ahead of you

Note:Note:

MVPT does not assess topographical orientation or sequencing, MVPT does not assess topographical orientation or sequencing,

both are important abilities to have when drivingboth are important abilities to have when driving

Do you remember where the cars surrounding you are?


Visual ClosureVisual Closure

See part of a car in See part of a car in front of youfront of you

Snow covered carsSnow covered cars

Tree that partially covers a signTree that partially covers a sign


Visual Spatial RelationshipsVisual Spatial Relationships

NOTE: MVPT does not test for person to object relationships, only object to object; does not test distance between objects, only orientation; does not test animated object relationships, only inanimate objects.

If you were driving into a If you were driving into a wooded area with many trees and wooded area with many trees and saw one had fallen on the road, saw one had fallen on the road, would you be able to see that it would you be able to see that it was out of place (and avoid it?) was out of place (and avoid it?)

Ability to tell your distance from Ability to tell your distance from the intersection so that you know the intersection so that you know when to start breaking when to start breaking

ParkingParking

Did you find all the faces?Did you find all the faces?

Thanks for Listening!Thanks for Listening!

All replications of diagrams from original assessmentsAll replications of diagrams from original assessments

Documents

Visual Perception Assessment “The mind can only see what it is prepared to see” - Edward de Bono OCT 1172: Neuroanatomy Tuesday, February 1 st, 2005 Nadia