Word recognition
in normal reading
Sara C. Sereno
Collaborators:
Paddy O’Donnell
Hartmut Leuthold
RAs/PGs:
Sébastien Miellet
Graham Scott
Christopher Hand
Word Recognition
• What factors affect word recognition?
• How can word recognition processes
be accurately measured?
• How can effects be interpreted?
What factors affect word recognition?
• Orthography of language
– English vs. Hebrew or Japanese
• Intraword (sublexical) variables
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–
–
–
word-initial bi/tri-grams
spelling-to-sound regularity
neighborhood consistency
morphemes
• prefix vs. pseudo-prefix
• compound vs. pseudo-compound
clown vs. dwarf
hint vs. pint
made vs. gave
remind vs. relish
cowboy vs. carpet
What factors affect word recognition?
• Word (lexical) variables
–
–
–
–
–
–
–
–
–
word length
word frequency
AoA
expert vocabulary
syntactic class
ambiguity
concreteness/imageability
animacy
affective tone
duke vs. fisherman
student vs. steward
rabbit vs. violin
voxel
open/closed-class; A,N,V
bank (“money” “river”)
tree vs. idea
dog vs. cup
love vs. farm vs. fire
What factors affect word recognition?
• Extraword (supralexical) variables
– Contextual predictability
Neutral
He bought a large plant for his garden.
Biasing
Terry went to the new gardening centre.
He bought a large plant for his garden.
– Syntactic complexity
Trans. Mary took the book
VERB
on the table.
was good.
the table.
Mary knew the book on
was good.
the table.
Intrans. Mary hoped the book on
was good.
What factors affect word recognition?
• Extraword (supralexical) variables
– Discourse factors
Focus The dog chased the cat today.
The cat was chased by the dog today.
What the dog chased was the cat today.
It was the cat that was chased by the dog today.
Elaborative inferences & anaphora
stabbed
… The mugger assaulted her with his weapon…
He threw the knife into the bushes and ran away.
What factors affect word recognition?
• Language skill
– beginning (novice) vs. skilled (expert) readers
– normal vs. dyslexic vs. neuropsychological patient
How can word recognition processes
be accurately measured?
Measure
Task
Time Res.
“electrical” imaging
(EEG, MEG)
single word presentation
word-by-word reading
~80 – 500 ms
(P1,N1,EPN,N400)
Eye movements in
normal reading
fixation time, location &
sequence of EM’s
~250 ms
RT
naming, lexical decision
categorization tasks;
± priming, masking,
lateralized presentation
~500 – 800 ms
“blood flow” imaging single word presentation
(PET, fMRI)
seconds
Word-by-word reading: 200 ms per word
presentation
reading-like
sentence
word
rate.
This
fast
by
of
at
is
a
Word-by-word reading: 600 ms per word
presentation
sentence
typically
studies.
word
used
ERP
slow
This
rate
by
of
at
in
is
a
Normal Reading
*
This is an approximation of normal reading
in real time.
*
This is an approximation of normal reading
in real time.
*
This is an approximation of normal reading
in real time.
*
This is an approximation of normal reading
in real time.
*
This is an approximation of normal reading
in real time.
*
This is an approximation of normal reading
in real time.
*
This is an approximation of normal reading
in real time.
This is an approximation of normal reading
* time.
in real
This is an approximation of normal reading
in* real time.
This is an approximation of normal reading
*
in real time.
The importance of making eye
movements in normal reading
Cond1
Cond2
There was a box of…
Cond1
Cond2
She saw a cat in the…
There was an enormous box of…
She saw a cup in the…
Perception of text influences how EMs made.
AND
Location/duration of EMs affect perception.
How can effects be interpreted?
• Additive factors
(1) Pick factors: stimulus quality, frequency, predictability
(2) Independently manipulate 2 factors at once:
Lo freq
RT
Hi freq
– stim
RT
Lo freq
RT
+ stim
+
–
stim qual
(3) Additive
Interactive
+
sequential
overlapping
Hi freq
+
–
context
–
context
Context
Stimulus
Quality
Frequency
How can effects be interpreted?
• Modelling
(1) Pick factors:
oculomotor-related factors
launch distance to word
location of fixation within word
number of fixations on word
word length
word frequency
contextual predictability
language-related factors
How can effects be interpreted?
• Modelling
(1) Pick factors:
oculomotor-related factors
launch distance to word
location of fixation within word
number of fixations on word
word length
word frequency
contextual predictability
language-related factors
(2) Perform repeated measures multiple regression analysis
to determine which factors account for most variance.
Factors
orthography
bi-/tri-grams
regularity
neighborhood
morphology
length
frequency
jargon
word class
ambiguity
imagability
animacy
emotionality
predictability
syntactic prefs.
focus
inference
anaphora
skill
Measures
ERPs
+
word-by-word
(slow) presentation
Eye movements
+
normal reading
EM-ERP
co-registration?
Approach
Additive factors
Repeated measures
multiple regression
lexical
humans
Distributed hierarchical visual processing in primates
higher-level
semantics
syntax
meanings
word forms
letters
features
Conclusion
Precisely delineating the time course of
different components of word recognition
allows us to:
– determine when top-down effects modulate
bottom-up processes;
– inform neuroimaging localisation studies in order
to construct a temporally realistic neural circuitry
of normal reading.
Measurement
EMs = best on-line measure
of visual word recognition in
the context of normal reading
ERPs = best real-time measure
of brain activity associated with
the perceptual and cognitive
processing of words
(Sereno & Rayner, Trends in Cognitive Sciences, 2003)
Sereno, Rayner, & Posner
(1998). NeuroReport.
Sereno, Brewer, & O’Donnell
(2003). Psych. Sci.
(Sereno & Rayner, Trends in Cognitive Sciences, 2003)