Transcript Ocular Motor Skills & Reading Fluency

Ocular Motor Complications
& Their Impact on the
Reading Process
Marva Gellhaus, PhD
SD School for the Blind & VI
July 24, 2010
AER International Conference
Little Rock, Arkansas
Objectives
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Define fixation, smooth pursuits & saccadic
eye movements & explain their importance
to reading fluency
Explain the impact of ocular motor
difficulties on reading fluency for student’s
with low vision
Explain why increasing a student’s span of
recognition & tapping into a student’s long
term memory are effective methodologies
Who observes and documents
ocular motor skills?
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Eye care specialists?
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Addressed in reports
Not specific to reading process (Medically based)
Parents? LD Teachers? Vision teachers?
Reading Teachers? Classroom teachers?
Occupational therapists?
Does anyone synthesize the ocular motor and
reading process information?
Ocular motor stress symptoms
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Intermittent blurred vision
Diplopia
Visual fatigue
Orbital aching
Eyes burning
Headaches
Eye Muscle Expectations
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Fixation-hold the image on the fovea
Vestibulo-ocular reflex-hold the image steady
during brief head rotations
Optokinetic-hold the images steady during
sustained head rotations & gaze shifting
Smooth pursuits-hold the images of moving target
on the fovea
Saccades-holds images of eccentrically located
objects of interest on the fovea
Vergences-images of both eyes “fuse” into one
image
Fixation
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Hold the central image of a stationary
object on the fovea
Pauses to take in information
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First grader pauses 224 times per 100
words
College student pauses 90 times per 100
words
Vestibulo-ocular reflex
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Hold the images of the seen world
steady on the retina during brief head
rotations
This may be abnormal with some brain
stem defects
Optokinetic
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Hold images of the seen world steady
on the retina during sustained and low
frequency head rotation and gaze
shifting
Smooth pursuits
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Hold the image of a moving target on
the fovea
Symptoms (difficulties noted)
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Jerking eye movements/midline tremors
Excessive head movements while reading
Poor performance in sports
Movements are in one direction
Saccades
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Directs images of eccentrically located
objects of interest on the fovea
Movements in more than one direction
Quick movements of both eyes in same
direction
Mechanism for fixation, re-fixation,
rapid eye movement
Saccades-Difficulties Noted
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Head movements
Frequent loss of place
Omission of words
Skipping lines
Slow reading speed
Poor comprehension
Difficulty with columns of numbers
Difficulty copying
Saccades-Difficulties Noted
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Letters compete for space near fovea;
results in visual crowding
Visual crowding observations tools
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Near Reading Card for the Partially Sighted
LEA Cards
Other Cards
Educator created cards for screenings
Saccadic Eye Movements
and Reading
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Muscle controlled saccadic eye
movements
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Linked to and affect span of visual
recognition (amount of visual information
formed on the fovea in a given fixation)
Good saccades-10 eye movements per line
Poor saccades-dramatic increase in eye
movements (Back tracking necessary to
pick up lost or unperceived information)
Saccadic Eye Movements &
Reading
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Span of fixation reduced when eye muscle
complication exist
Each fixation must be remembered in
sequence to put a line together
Multiple visual fixations have multiple auditory
(phonetic) components
Reduced span of recognition and
uncontrollable eye movements make process
of reading significantly more complex
Vergence
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Moves the eye movements so that
images of a single object are placed
simultaneously on the foveae of both
eyes and the image fuse to send one
image back to the brain
Main concerns for reading
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Fixation
Smooth pursuits
Saccades
Vergence
Sole purpose of the ocular motor
system is to keep the image we are
looking at on both foveae at the same
time
Observations by Evaluator
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Have child track object: move object
horizontally, vertically, and diagonally
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Do eyes move smoothly together,
horizontally, vertically and diagonally?
Have child watch your finger move
toward his/her nose
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Do eyes move smoothly inward as object is
moved towards nose?
Next Step-Documentation of
Eye Condition
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Existing eye care specialist’s reports can
be examined to determine current
documentation from eye care specialists
Observation and inquiries should be
recorded for further investigation and
documentation by eye care specialists
Teaching Reading?
Now What?
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Learn implication of weak/poor eye
movements on the reading process
(DONE!)
Move information from short to long
term memory
Increase a student’s span of recognition
Memory & Reading 1
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Input into sensory store is affected by
acuity, span of visual recognition,
number of fixations, visual field,
magnification--Visual input and information from long
and short memory store are integrated
to create reading comprehension
Long Term Memory & Reading
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Reading (decoding) and comprehension
are heavily dependent on information
retrieved from long term memory.
The more information that is stored in
long term memory, the less processing
(use of visual and auditory memory and
sequencing) that is needed for reading.
Long Term Memory & Reading
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Sight words are stored in long term
memory and quickly retrieved.
Experience and concepts are stored in
long term memory.
How Can We Improve Reading
Fluency?
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We must increase a
student’s span of
recognition.
Increasing Span of
Recognition 1
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Display for 1 second
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Series of letter
Meaningful clusters (grouping and
chunking of words and whole words)
Add context (meaningful sentence)
The more information we have in long
term memory, the less processing we
have to do.
Increasing Span of
Recognition 2
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Span of recognition can be increased by
chunking or grouping letters together in
a single meaningful symbol.
Phonetic approach-requires sequencing
of four sounds (b-r-o-k-e)
Chunking approach-requires sequencing
of two sounds (br-oke): visual &
auditory sequencing greatly reduced
Learning Chunks
(Prerequisite skills)
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Identify rhyming sounds auditorily
Identify sounds of all consonants used
in the lesson
Know sight word of one of one member
of the word family
Chunks-Increasing Span of
Recognition
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Practice with chunks; repetition of
chunks (initial sound with chunks)
(Knowledge of phonics is necessary, but
this process is simplified by learning
one syllable sound/spelling patterns
known a chunks)
Chunks-Word Families
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Word families, sound families,
phonograms or rhymes are consistent
one syllable sound/spelling patterns
found in a series of words
500 primary grade words can be
derived from 37 high frequency word
families.
Learning Word Families
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500 primary grade words are derived
from the 37 high-frequency words word
families listed below
-ack –ail –ain –ake –ale -ame –an –ank
-ap –ash –at –ate –aw –ay –eat –ell
-est –ice –ick –ide –ight –ill –in –ine
-ing –ink –ip –id –ock –oke –op –ore –ot
-uck –ug –ump -unk
When you get home--
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Observe and document student’s eye
movements
Help student place information in long
term memory
Increase student’s span of recognition
by using the “Chunk Method”
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Teach word families
Practice, practice
Bibliography
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Developing Ocular Motor and Visual
Perception Skills by Kenneth Lane
Dr. Dorothy Perkins-Professor of Reading
Psychophysics of Reading in Normal and Low
Vision by Gordon E. Legge
The Reading Teacher’s Book of Lists by E. B.
Fry, J. K. Polk, and D. Fountoukidis
Marva’s Website: www.beanybooks.com