Reading and Eye Movements Flashcards
Why do we need reading?
- Individual words – need to be able to identify
- Sentences->paragraphs->books – putting the words together
- Existing knowledge e.g. the alphabet
- Navigation
Why eye movements?
- Need to navigate the text
- A lot of research in the area
- Research has been going on for about 120 years
- Huey, 1898 – tried to look at someone’s eyes whilst they were reading, struggled to find participants
What is the eye-mind assumption?
- “the eye remains fixated on a word as long as the word is being processed. So the time it takes to process a newly fixated word is directly indicated by the gaze duration” Just & Carpenter 1980 p.330
- Non-invasive, relatively low-cost, sensitive online measure of cognitive processing during reading, use of a camera takes sample every ms
- Inform reading instruction, identify reading difficulty, inform design
What has eye tracking found when looking a children being read to?
- Using eye tracking
- Only interested in image when they don’t know how to read
- Look at the picture and some of the text when being read to if they know how to read
How do you perceive a word?
- Need highly detailed (central) vision for accurate perception of word form
- I.e. need to make a fixation on(almost) every word
- Make short saccades between the words
What are the Oculomotor patterns?
- Fixations ~200ms
- Most words receive at least one direct fixation
- Skips ~20%
- Saccades ~15-40ms, ~5-9 chars
- Mostly progressive
- ~10-15% regressions
- = average reading speed ~250-350wpm
What is a Saccade?
one it is set off can’t stop it, directive one shot movement to change gaze position
What is refixation?
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What is fixation?
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What is skip?
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What is regression?
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What is return sweep?
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What are the factors influencing EM behaviour?
- Characteristics of the visual system
- Attention
- Online cognitive processing of text
- Personal characteristics
- Task differences
- Text differences
What does the Retina contain?
- Rods
- Lower acuity
- Peripheral retina
- Monochromatic
- Work at lower light intensities
What does the Fovea contain?
- Cones
- Better acuity
- Central retina
- Trichromatic (colour vision)
When is something considered high detail?
Oyster 1999
- Directly looking at something = high detail
- If you’re not looking straight ahead
What is text like with Online processing?
- Clear effects of certain text characteristics on metrics such as fixation duration
- Looking at effect of different manipulations on different measures can help us understand how text is processed during reading
- Manipulate a target word itself or sentence context and compare oculomotor behaviour on target word
- E.g. word length, word frequency, sentence predictability, sentence plausibility, syntactic ambiguity…
Can Word length have an effect?
- Short words are processed quicker
- Perceptual effect:
- Same pattern X-strings
- Fixation on longer words due to the amount of visual information
What is early processing?
‘Early’ processing –single fixation duration, first fixation duration, skipping probability –the initial familiarity/identification stages
What is late processing?
-‘Late’ processing –total gaze duration, regression probability, go-past duration –the stuff that comes after, integration into wider representation of the text
Where is your attention when reading?
- Mostly deployed to upcoming text (ahead of point of fixation) to begin processing
- Small allocation behind fixation
- Single line
What is Word identification span and how do you investigate it?
- Word identification span –slightly asymmetric (~4L-7R)–close to average progressive saccade size (7 characters)
- Investigate with boundary change paradigm –gaze contingent boundary, different preview to fixated word –see if you notice the difference
What is the boundary change paradigm?
- Use a eye tracker which uses an invisible boundary, and if the boundary is crossed the sentence will change, participant will be asked if they noticed the change
- Underwood and McConkie 1985
What is perceptual span?
- Asymmetric –spans around 4 characters to left and 15 characters to right of fixation
- Constrained under higher foveal load – if you’re looking at something directly which is difficult to read, less attention around the fixation
- Information about word form, inter-word spacing
- Gaze-contingent moving window paradigm (McConkie& Rayner 1975) – using a window where the eye tracker can surround words with x’s
How do we know perception is to do with attention and not the visual span?
- Reversed for orthographies that are read the other way (e.g. Hebrew)
- Shrunk for more dense (/complicated orthographies; e.g. Chinese, 1L 3R)
- Not affected by parafoveal magnification – argued that if the surrounding text is bigger, acuity should be improved
What are the Two main competing models?
- E-Z Reader –serial
2. SWIFT –parallel
What is the E-Z Reader Model?
- Serial model
- Attention deployed to one word at a time
- Two stages of lexical processing
- Saccade planned after first stage is complete
- If 2nd stage is completed as well before this is executed, attention shifts to the next word – saccades are planned for following words in this way until both stages of lexical processing of word (n+x) can’t be completed before the saccade programme is implemented (intervening words are ‘skipped’)
- If 2nd stage isn’t completed before the saccade is executed, a regression may be programmed to return and complete processing
What is the SWIFT model?
- Parallel model
- Words around point of fixation activated to different extents, dependent on early low-level processing which occurs in parallel
- Saccadic shifts are programmed at random intervals to the word receiving highest activation
- Shift might be delayed up to a point by higher processing difficulty on foveated word n than planned saccade target –if delay isn’t sufficient to complete processing before a saccade, activation for this word will be increased and therefore increase likelihood of later regressive saccade
Can word frequency effect how you perceive words?
- Less frequently encountered words take longer to process
- Measure of successful word identification
- E.g. town = high frequency, cove = low frequency
What did Fitzsimmons, Weal, & Drieghe 2014 find when using hyperlinks on websites?
- Reading on websites
- Compared normal reading with skim reading
- Typical text or text with hyperlinks in it
- Loss of word frequency effect for unlinked words demonstrates that when skimming text with hyperlinks, readers only tend to process the linked words properly
- Real-world application: Don’t put important information in between hyperlinks!
Can word predictability have an effect?
- Words that are easier to predict from preceding context are processed quicker
- High predictability: Russell had hurt his hand in the door of the car. He had trapped his finger while playing.
- Neutral: Russell had to go to the hospital. He had trapped his finger while playing.
Can font have an effect?
- Cursive
- Small inter-letter and inter-word spacing
- Colour/contrast
What Other text effects are there which can affect perception?
- Language
- Difficulty of content
- Display format
Can text difficulty have an effect?
- Some texts are easier to read than others
- Whether it is text heavy or not
- Fixation on more difficult texts (increases)
- Reading speed decreases the harder the text gets
- Rayner & Pollatsek (1987)
What did Liversedgeet al. 2016 find about how different languages are perceived?
-English, Chinese and Finnish
-Finnish has longer words
-Chinese takes longer to read, English and Finnish are fairly similar
-Higher saccade length for English and Finnish, lower for Chinese
-Average fixation length is longer for Chinese, similar time for English and Finnish
What are the different ways text can be laid out?
- Normal static text
- RSVP – good for speed reading
- Drifting/horizontally scrolling text – moves across the screen
- Marquee text – moves up the screen, each word on each line
What is Horizontally scrolling text ?
- Need to swap out static fixations for smooth pursuit to track moving words
- Doesn’t seem to have much impact on single word processing
- Does reduce sentence-level integration of info (& therefore comprehension)
- Long words take longer to process
What is RSVP?
- High speeds affects comprehension and memory
- No preview of what’s coming up
- No going back
What purposes are there for reading?
- Reading for comprehension
- Reading for pleasure
- Skim reading
- Proofreading
What happens when you read aloud?
Reading aloud = longer fixation durations (~50ms) and shorter saccades (~1-2 chars) –need to keep roughly in step with the voice (eye-voice span), accuracy more important
What happens when you read fast/skim read?
Longer, fewer saccades, more skips, less idea of details
What happens when you proofread?
- More careful reading shorter saccades, longer fixations, more refixations
- More focus on word-level processing
- Gaze duration longer when proofreading
Can individual differences have an effect?
- Individuals are consistent in their own oculomotor behaviour when reading
- Variation between people
What is reading like for young readers?
- More variable eye movement behaviour
- More refixations, more regressions, shorter saccades, fewer skips, longer fixations (~300+ms)
- Smaller perceptual span (~11 cf. 15 characters to right of fixation)
- Similar pattern to adults by around age 11 – except perceptual span and regression rate
- Perception span takes a while to develop, reaches adult development by 16
What is reading like for older readers?
- ‘Risky’ reading strategy –more skips, longer saccades
- Longer fixations, more regressions –slower reading times
- BUT not universal: Chinese vs. English, older Chinese have more cautious oculomotor pattern than younger Chinese (Rayner, Reichle & Stroud, 2006; Wang et al., 2016)
What individual differences effect how we perceive text?
- Special populations:
- Poor comprehenders
- Deafness
- Visual impairments
- MCI/AD
How can Poor comprehenders effect text perception?
- Less efficient oculomotor pattern -make more fixations, shorter saccades, have smaller perceptual span
- Poor comprehendersare less able to integrate information across text passage
How can deafness effect text perception?
- Typically learn by associating phonology (sound) with orthography (written form)
- Reportedly high levels of reading difficulty/illiteracy in deaf population
- Less skilled deaf readers have the same perceptual span as more skilled hearing readers
- Highly skilled deaf readers (approx 5%) have increased perceputal span cf. matched hearing readers
What is Macular degeneration?
- Most common cause of legal blindness
- Loss of central vision
- Visual distortion (metamorphopsia)
- Fixation instability
- Counterproductive attempts to foveate
What is a Glaucoma?
- Loss of peripheral vision
- Effective shrinking of perceptual span
- Increased density of eye movement
How can Early Alzheimer’s disease effect text perception?
- More fixations and saccades
- Longer fixations
- Shorter saccades
- More regressions
- More skipping
- Breakdown of relationship between saccade length and fixation duration
- Breakdown of relationship between word/sentence characteristics and oculomotor behaviour
