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8/3/2019 Visual Processing Home

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Visual Processing

Diane Cullinane, M.D.


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Goals

1. See that vision is the most importantsense

2. Vision is complex (and fascinating)3. Visual deficits can affect behavior, learning,

and relating

4. We all need to be aware of, and tailorinteractions to, a childs visual abilities

5. Instill humility- we are still in the dark ages


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Visual Processing:

complex

Use central and peripheral vision Detect Attend Hold attention

Use eyes to examine Perceive qualities of shape, color, location, and

movement Pattern discrimination Visual repair Match to previous representation Interpret meaning Remember


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And then..

Use representations to plan,anticipate, think logically

Communicate Fix gaze

Avert gaze

Lock gaze Shift gaze

Direct gaze


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Visual processing:

more complex

One form of Sensory processing Visual Auditory

Touch Proprioceptive Vestibular Smell and taste

Visual processing is influenced by all othersensory processing and vision influencesthem


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Sensory potentials

Localization theory of the brain

Plasticity- many potentials, depends on

how it is used; brain actuallyrestructures itself


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Visual processing- a

developmental process

Vision takes up largest portion of thebrain

Vision is least functionally mature atbirth

Normal infant is auditory dominant


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Development of Vision

Skills: 2 months

Watch parents from a distance

Deliberate shift gaze between two

people or objects (simple visualpreference)


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3 months

Vision is more dominant

Eye contact is coupled with increased

limb movement Preference for people over objects

Will grasp and bring object into visual

field


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4-6 months

Recognizes a person on sight andsmiles selectively

Reaching/grasping is visually guided (visual and proprioceptive feedback)

Inspect and examines object from

different angles

Look for object that falls


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6-8 months

Can predict the reappearance of anobject (object permanence)

Understands picture represents anobject (attempts to take picture)

Follows direction of your gaze

Greater looking at mothers mouth at 6months predicts expressive language at18 months


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9-12 months

Looks by word alone

3 point looking

Shows a toy

Social referencing influences action

12 months: proto-imperative pointing

14 months: proto-declarative pointing


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DMIC Axis V: 6

Visuospatial Capacities

1. Body awareness and sense

2. Location of the body in space

3. Relation of objects to self and otherobjects and people

4. Conservation of space

5. Visual Logical reasoning6. Representational Thought (drawing,

thinking, visualizing)


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Susan R. Barry,

Fixing My Gaze

Most surprising to me was that thechange in my vision affected the way I

thought. I had always seen andreasoned in a step-by-step manner. Isaw with one eye and then thenext.when I learned to see

simultaneously with two eyesonlythen was I aware of the whole forestand within it, the trees.


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Vision Skills

1. Tracking (follow moving object, ocularpursuit)

2. Fixation (locate and inspect stationeryobject/s, in succession)

Saccades: The ability to switch fixation

from one target to another


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Vision Skills, contd

3. Focus Change (far to near)Accomodation- ciliary muscle holds

and controls lens Poor accomodationcause intermittent blur, difficultyshifting attention

4. Depth Perception5. Peripheral Vision


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6. Binocularity

Convergence and Divergence

Eye teaming Necessary for comfort vs. headaches andeye strain, fatigue

blinking, red eyes, rubbing or covering eye,

poor attention span Compensation: cortical inhibition, lose depth

perception


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7. Maintaining Visual Attention

8. Near Vision Acuity

9. Distance Acuity

Do all this when still, and while moving


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Visual Perception

Visual discrimination

Similarities and differences

Visual memory Visual-spatial relations

Orient body in space and perceive the

position of objects in relation tohimself/herself or other objects.


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Visual Perception

Visual form constancy

Recognize regardless of orientation

Difficulty distinguishing b and d Difficulty recognizing things when

environment changes

Mentally manipulate forms (visualize)


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Visual Perception

Visual sequential memory

Visual figure-ground

Difficulty organizing personal belongings

Miss the big picture, or misses importantdetail

Lack visual search strategies Visual closure


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Visual-motor skills

Eye hand coordination

Fine motor

Gross motor

Praxis (ideation, planning, execution,sequencing)


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Visual Pathways

Eyes (photo-receptors- rods and cones)

Thalamus (in brain stem)

Visual Cortex


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Ontongeny

Vision was initially a modulator for movement,largely unconscious process, it helped adaptsuch as moving through space to get foodand escape from enemies.

Later vision advanced to have visualrepresentations

The two systems are segregated beginning atthe retina


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Where? system (Magno-cellular)

Older

Large-cell

Motion, space, position, depth, figure/ground, and

Overall organization Color blind

High sensitivity to contrast, lower acuity

Faster and more transient

Functions from birth Largely unconscious process

Linked to PMC, guides movement


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What? system (Parvo system)

Small-cell Only in primates; Recognize objects, including faces, color and

detail More acuity; sensitive to finer detail, subtle

contrast Meaning; enduring characteristics

Form (borders) and surfaces Temporal lobe Becomes active at 2 months of age


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Praxis

Requires:

1. Basic motor skill (motor cortex)

2. Postural knowledge: representationsof the movement (time-space) (parietalcortex)

3. Movement plans (premotor cortex)


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Mirror neurons

Deficits in autism affect imitation

Concepts of self-other


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Individual Differences:

Visual preferences

We all have individual differences-

Prefer near or far and wide

Read while moving

Level of visual stimuli

Skills with puzzles, etc.


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Individual Differences

Chart

1. Observe and focus on desiredobject

(first must explore space)

2. Alternate gaze

(initiate joint attention visually)


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Chart

3. Follow anothers gaze to determine the

object of their attention and their intent

(respond visually)3 (again) Switch visual attention back

and forth between self and other (self

monitor, other monitor & integration)


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Chart

4. Differentiate salient visual stimuli frombackground stimuli (visual figure

ground)


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Chart

5. Actively search for object she seeshidden

6. Can explore two areas of room andsearch for desired object

7. Can explore more than two areas with

active visual assessment of space,shape and materials.


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I add

8. Organizes toys in close proximity

9. Aware of body in context to toys and otherpeople

10.Purposeful movement in relation to othersmovement

11.Organizes larger play space

12.Visual-spatial problem solving13.Utilizes abstract materials to represent

space


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Modulation Disorder

Over- responsive

Over sensitive to light

Easily distracted by visual input

May startle easily

Tend to avoid eye contact

May cover eyes

Helped: sunglasses; hat

M d l ti Di d


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Modulation Disorder:

Under-responsive

Increased tolerance for strong visualinput

Failure to attend Failure to alert to peripheral fields

M d l ti Di d


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Modulation Disorder:

Sensory-seeking

May seek toys with moving parts orflashing lights

Vi l Di i i ti


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Visual Discrimination

disorder

An impairment in the ability to interpretwhat is seen. A visual discrimination

disorder may affect the ability tocorrectly identify shapes and forms;match visual elements; remember visualinformation; or recognize objects thatare partially concealed.

Lucy Jane Miller, PhD OT


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Where is affect?

I could revert to my old strabismic ways

under stressful conditions..Now I

discovered that we cant understandhow we perceive the world and how weadapt and learn without considering thewhole person- the thinking, moving, andfeeling person. Susan R. Barry

Fixing My Gaze


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Where is affect?

Attention: Guides where we look

Modulation of response: level of

arousal Meaning: How things are stored in

memory


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Who? system

Sh t t t


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Short cut system:

Thalamus-Amygdala

B h i i t d ith


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Behaviors associated with

poor visual processing

Visual monitoring Look at feet

Being silly

Give up

Overflow movements Sequential rather than simultaneous movements

Break the chalk and drop the eraser

Fatigue

Blinking and yawning Sloppy writing; poor organization on the page


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More Behaviors

Bumps into objects and other people Misjudges distances while jumping Difficulty orientating hand and modulating

grasp Walks perimeter Anxious Isolated, passive, aloof

Delinquency Illiteracy


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Even more behaviors

Forgets which way to room

Takes circuitous route

Doesnt turn in homework

Chooses not to play with dollhouse

Avoids coloring

Play space is disorganized

Never looks up


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Where system dominates

Look at spinning objects

Line up objects

Follow lines while walking

Wiggle fingers in front of eyes


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What system dominates

Hyperlexia

Fixate on details

Memorize signs and words


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Affect diathesis hypothesis

Use affect to build connections!!!

Connect to sound, vestibular,proprioception, tactile, smell and taste


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Vision Therapy

www.covd.org

www.oep.org

Visual efficiency: accommodation, binocularvision, ocular motility (saccadic, pursuit,fixation, nystagmus

Visual information processing: visual/spatial,

visual analysis (discrimination, figure/ground,visual closure), visual memory, visual motor
http://www.covd.org/http://www.oep.org/http://www.oep.org/http://www.covd.org/


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Vision Therapy

Joint statement July 2009 AAP and AAO Scientific evidence does not support the

efficacy of eye exercises, behavioral vision

therapy or special tinted filters or lenses forimproving the long-term educationalperformance learning disorders includingreading disabilities

Not endorsed and should not berecommended

www.covd.org
http://www.covd.org/http://www.covd.org/


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They also say

Only convergence insufficiency and pooraccommodation, which are uncommon, caninterfere with the physical act of reading butnot with decoding

Routine pediatric vision screenings areunlikely to disclose near-vision problems such

as convergence insufficiency,accommodative insufficiency and significanthyperopia


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Things to do

Understand causes of behavior

Occupational therapy

Consider the environment Consider the toys

Just right level of challenge


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A complex problem requires a complex

solution . Stanley Greenspan, M.D.

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