word recognition in normal reading sara c. sereno collaborators: ras/pgs: paddy...

Word recognitionin normal reading

Sara C. Sereno

Collaborators: RAs/PGs:

Paddy O’Donnell Sébastien Miellet

Hartmut Leuthold Graham Scott

Christopher Hand

Word Recognition

• What factors affect word recognition?

• How can word recognition processes be accurately measured?

• How can effects be interpreted?

• Orthography of language– English vs. Hebrew or Japanese

• Intraword (sublexical) variables– word-initial bi/tri-grams clown vs. dwarf– spelling-to-sound regularity hint vs. pint– neighborhood consistency made vs.

gave– morphemes

• prefix vs. pseudo-prefix remind vs. relish• compound vs. pseudo-compound cowboy vs. carpet

What factors affect word recognition?

What factors affect word recognition?

• Word (lexical) variables– word length duke vs. fisherman– word frequency student vs. steward– AoA rabbit vs. violin– expert vocabulary voxel– syntactic class open/closed-class; A,N,V– ambiguity bank (“money” “river”)– concreteness/imageability tree vs. idea– animacy dog vs. cup– affective tone 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 Mary knew the book

Intrans. Mary hoped the book

on the table.was good.

on the table.was good.

on the table.was good.

• 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

What factors affect word recognition?

… The mugger her with his weaponweapon…

He threw the knife into the bushes and ran away.

stabbedassaulted

What factors affect word recognition?

• Language skill– beginning (novice) vs. skilled (expert) readers– normal vs. dyslexic vs. neuropsychological patient

How can word recognition processesbe accurately measured?

Measure Task Time Res.“electrical” imaging single word presentation ~80 – 500 ms (EEG, MEG) word-by-word reading (P1,N1,EPN,N400)

Eye movements in fixation time, location & ~250 ms normal reading sequence of EM’s

RT naming, lexical decision ~500 – 800 ms categorization tasks;

± priming, masking, lateralized presentation

“blood flow” imaging single word presentation seconds (PET, fMRI)

Thisisawordbywordpresentationofasentenceatafastreading-likerate.

Word-by-word reading: 200 ms per word

Thisisawordbywordpresentationofasentenceataslowratetypically usedinERPstudies.

Word-by-word reading: 600 ms per word

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

in real time.*

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 There was a box of…

Cond2 There was an enormous box of…

Cond1 She saw a cat in the…

Cond2 She saw a cup in the…

Perception of text influences how EMs made.

AND

Location/duration of EMs affect perception.

(1) Pick factors: stimulus quality, frequency, predictability

• Additive factors

How can effects be interpreted?

StimulusQuality

Context

Frequency

RTLo freq

Hi freq

+ – stim qual

RT

+ – context

– stim

+ stim

RT

+ – context

Lo freq

Hi freq

(3) Additive sequential Interactive overlapping

(2) Independently manipulate 2 factors at once:

oculomotor-related factorslaunch distance to wordlocation of fixation within wordnumber of fixations on wordword lengthword frequencycontextual predictability

language-related factors

How can effects be interpreted?• Modelling

(1) Pick factors:

oculomotor-related factorslaunch distance to wordlocation of fixation within wordnumber of fixations on wordword lengthword frequencycontextual predictability

language-related factors

How can effects be interpreted?• Modelling

(1) Pick factors:

(2) Perform repeated measures multiple regression analysis to determine which factors account for most variance.

Factors Measures Approachorthographybi-/tri-gramsregularityneighborhoodmorphologylengthfrequencyjargonword classambiguityimagabilityanimacyemotionalitypredictabilitysyntactic prefs.focusinferenceanaphoraskill

ERPs+

word-by-word(slow) presentation

Eye movements +

normal reading

EM-ERPco-registration?

Additive factors

Repeated measuresmultiple regression

Distributed hierarchical visual processing in primateslexical humans

higher-levelsemantics

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, Trends in Cognitive Sciences, 2003)

Sereno, Rayner, & Posner (1998). NeuroReport.Sereno, Brewer, & O’Donnell (2003). Psych. Sci.