Reading Eye Movements Flashcards
T/F reading eye movements are some of the more complex movements we make
true
What are characteristics of reading eye movements?
saccades NOT pursuits, internally driven, include perceptual aspects
What are perceptual aspects of reading eye movements?
text processing, comprehension, short term memory, generally interest, language
Who discovered that reading eye movements are saccades not pursuits?
javal 1879
What are the three basic patterns of reading eye movement?
fixations, regressions, return sweep
Describe the reading fixations
1-2 degrees, average 8 characters apart (english)
Describe reading regressions
only a few characters, text confusion/comprehension
Describe reading return sweeps
saccade to next line, 12-20 degrees, 6th character from end to 6th character in
What technology records reading eye movements?
readalyzer
T/F we fixate on each word when we read
false
How does skimming differ from reading?
way fewer fixations in skimming
What is the perceptual span of reading?
amount of text processed during a fixation, asymmetric
How long is the perceptual span in english?
extends from 4 characters to the left of fixation over to 15 characters to the right of fixation
T/F successive perceptual spans overlap
true, allows for integration of info
How long is the fixation duration?
225 msec (remember this is saccadic latency) but also is text dependent
What is the reading rate for an average college reader?
290-300 words per minute (w/ minimum of 70% comprehension)
What is the reading rate for skimming?
400-500 words per minute
What is the average duration of fixation for college level reader?
240 msec
How many fixations to college readers use for 100 words?
90
How many regressions does a college reader have for 100 words?
10
What approach are we using when we don’t fixate on every word?
top down approach
What is the top down approach?
we form perceptions starting with the larger concept or idea and then working down to finer detail
How is central retina involved in reading?
used for basic resolution, when occluded get worst comprehension and slowest reading rate
How is parafoveal retina involved in reading?
near parafovea used for semantics and far parafovea used for motor planning
How does a scotoma affect reading?
scotoma to R worse than scotoma to L due to poor planning ability; no adverse effect with supra/infra foveal loss
How often do we sample the world for changes?
4-5 times per second
T/F our perception of the world is always just a bit behind the actual events that occur in space
true
Where do good readers look when they fixate words?
1/3 of the way into the word
T/F we made the same size reading saccade every time
false
How do immature readers saccade?
they saccade too big to the right from lack of fine control of oculomotor system and lack of knowing where to go and attention window too small, to fix must make small saccade left, lots of regressions
In normal readers what percent of saccades are regressions?
12-15%
In poor readers what percent of saccades are regressions?
35-40%
What percent of words do you need to read to understand what you’re reading?
9%
What are tracking problems?
many more fixations, more regressions and have to reassemble chunks of text for meaning, get bored during process, mismatch of speed is problem
What are the two main types of dyslexia?
developmental/congenital and acquired
What is developmental dyslexia?
reading disability, at least 2 years behind expected grade level, normal intelligence, normal sensory vision, no neuro or emotional disorders
What are the two subgroups of developmental dyslexia?
language deficit and visual spatial
What is language deficit developmental dyslexia?
poor performance with age-level material, better performance with reading level material, problem is with language processing
What is visual-spatial developmental dyslexia?
much less common, poor return sweeps, reverse staircases, problem with visual spatial relations
T/F poor eye movements cause dyslexia
false
What is acquired dyslexia?
reading disability in previously normal reader, result of neuro insult like stroke
What are complaints of acquired dyslexia?
reduced comprehension, difficult in sequencing, problems maintaining fixation, need to move head
When does dyslexia treatment involve optometry?
many surgeries overlap with BV dysfunction, OMD perceptual issues, VT eval
What is the breitmeye/lovegrove hypothesis?
an older hypothesis about how magno and parvo interact in reading
What system has a sustained response?
parvo
What system has a transient response?
magno
What is the purpose of the transient/magno response?
to suppress the info in the overlap area and minimize confusion so better perception
What is the magnocellular deficit theory of dyslexia?
postulates that dyslexia is the result of reduced sensitivity in the magnocellular system
What is the cause of dyslexia through the magno/parvo mindset?
dyslexia is the result of a failure to keep separate neural activity during different fixations
What is the transient system deficit theory?
magno system suppresses the parvo system during each saccade causing the activity of the parvo system to terminate and prevent lingering
What does the breitmeyer/lovegrove theory fail to address?
how we figure out where our next fixation should go
What is the preview system?
looks ahead and pre-processes spatial info about the size of words, where they begin, and where they end
What system do we use to pre-process?
magno and parafoveal
What is wrong about the Breitmeyer/lovegrove hypothesis?
magnocellular system can’t just be an eraser, the two streams do not reassemble together to form a unified image
What is the current preview system hypothesis?
fixation point is parvo and preprocess zone is magno
What is gestalt and how does it help?
the general shape of the word, tells us how long the word is so we don’t have to guess where 1/3 of the way in is
T/F parvo and magno systems work simultaneously during reading?
true
What happened during the lateral masking experiment?
target identification in eccentric position, good readers could not correctly ID by 5 degrees eccentricity while dyslexic patients could correctly ID further out from fovea
Why can dyslexic patients better ID letters in eccentric position?
there is a making effect losing detail further out, only use shape of info to plan movements… good thing, detail gets in the way so good readers don’t use it
T/F “software” of fixation in reading is language dependent
true
What is a garden path sentence?
used in psycholinguistics to illustrate that humans process language one word at a time, have confusing sentence structure
What do poor music sight readers do?
look at what they are currently playing, make more mistakes, never look at dynamics, little preview
What do good music sight readers do?
more fixations, more regressions, lots of jumping ahead, do not get stuck
What is the poor and good sight readers; ration of regressions to fixations?
poor 20-24%; good 50-57%
How is oration different than reading out loud?
an orator uses massive look-ahead where current visual input is well ahead of the actual spoken voice
