parafoveal processing influences word frequency & predictability effects on eye movements during...

Parafoveal Processing InfluencesWord Frequency & Predictability

Effects on Eye Movementsduring Reading

University of Glasgow(est. 1451)

GlasgowLanguageProcessing

Christopher Hand

Sébastien Miellet

Paddy O’Donnell

Graham Scott

Emotion Word Processing:Evidence from Eye Movements

Scott, O’Donnell, & Sereno

Frequency & Predictability

• Word frequency– High-frequency (HF) words are read more quickly

than low-frequency (LF) words.– A word frequency effect (HF<LF) is used as a marker

(index) of successful word recognition (lexical access).

• Contextual Predictability– Given a prior context, words that are highly predictable

(HP) from context are read more quickly than those that are less predictable (LP).

– The temporal locus of predictability effects, lexical (interactive) or post-lexical (modular), is a matter of continued debate.

Freq X Pred: Early RT Studies

Stanovich & West (1981):Naming

700

750

800

850

900

950

1000

Incongruous Congruous

Predictability

RT

(m

s)

LF

HF

Schuberth & Eimas (1977):Lexical Decision

500

550

600

650

700

Incongruous Congruous

Predictability

RT

(m

s)

LF

HF

Additive Interactiveor

TargetCondition Context HF LFCongruous The skier was buried in the…Incongruous The bodyguard drove the…

snowsnow avalancheavalanche

TargetCondition Context HF LFBiasing Flying to its nest was a…Neutral To our surprise we saw a…

bird bird hawkhawk

1

1.2

1.4

1.6

1.8

2

Neutral Biasing

Predictability

Un

sig

ned

Vo

ltag

e (μ

V)

LF

HF

Freq X Pred: ERP Study

Sereno, Brewer, O’Donnell (2003)

N1 component: 132-192 ms

Freq X Pred: Eye MovementsAltarriba, Kroll, Sholl, & Rayner (1996)Lavinge, Vitu, & d’Ydewalle (2000)Rayner, Binder, Ashby, & Pollatsek (2001)- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Rayner, Ashby, Pollatsek, & Reichle (2004)Miellet, Sparrow, & Sereno (in press)

Inhoff (1984)

500

550

600

650

700

Low High

Predictability

Fix

ati

on

Du

rati

on

(m

s)

LF

HF500

550

600

650

700

Low High

Predictability

Fix

atio

n D

ura

tio

n (

ms)

LF

HF

Freq X Pred: Eye MovementsAltarriba, Kroll, Sholl, & Rayner (1996)Lavigne, Vitu, & d’Ydewalle (2000)Rayner, Binder, Ashby, & Pollatsek (2001)- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Rayner, Ashby, Pollatsek, & Reichle (2004)Miellet, Sparrow, & Sereno (in press)

Inhoff (1984)

500

550

600

650

700

Low High

Predictability

Fix

ati

on

Du

rati

on

(m

s)

LF

HF500

550

600

650

700

Low High

Predictability

Fix

atio

n D

ura

tio

n (

ms)

LF

HF

conducteden

français

Bugs Bunny eats lots of carrotscarrots to stay healthy.

June Cleaver always serves meat and potatoespotatoes for dinner.

LF

HF

High Predictability

June Cleaver always serves meat and carrotscarrots for dinner.

Bugs Bunny eats lots of potatoespotatoes to stay healthy.

LF

HF

Low Predictability

Rayner et al. (2004)

Rayner et al. (2004)

Limitations Remedies

Items per condition:8

Targets embedded in:single sentence

Length of context (# pre-target words):7.7 words

22

15.5

2nd of 2sentences

Bugs Bunny eats lots of carrotscarrots to stay healthy.

June Cleaver always serves meat and potatoespotatoes for dinner.

June Cleaver always serves meat and carrotscarrots for dinner.

Bugs Bunny eats lots of potatoespotatoes to stay healthy.

LF

LF

HF

HF

High Predictability

Low Predictability

Although a rugby player, Clive struggled through the crowdat the bar carrying glasses of lagerlager and bags of crisps.

Gillian was on the last mile of the women’s marathon. Shegrabbed a bottle of waterwater from a spectator and drank it.

Gillian was on the last mile of the women’s marathon. Shegrabbed a bottle of lagerlager from a spectator and drank it.

Although a rugby player, Clive struggled through the crowdat the bar carrying glasses of waterwater and bags of crisps.

LF

LF

HF

HF

High Predictability

Low Predictability

Ingrid’s boiler had suddenly broken down. Fortunately, herneighbour’s father was a plumberplumber and would be able to help.

Callum was having trouble with his homework. He asked hisuncle who was a teacherteacher to help him with the assignment.

Callum was having trouble with his homework. He asked hisuncle who was a plumberplumber to help him with the assignment.

Ingrid’s boiler had suddenly broken down. Fortunately, herneighbour’s father was a teacherteacher and would be able to help.

LF

LF

HF

HF

High Predictability

Low Predictability

Method

• Materials & Design:Frequency (HF,LF) x Predictability (HP,LP)

HF & LF targets matched pair-wise on word length (mean = 5.84 letters; range: 5-8 letters)

HF LF

HP LP HP LP

Frequency (BNC, per million) 145 145 4 4

Predictability (1-7) 6.19 4.07 6.11 3.69Cloze probability .57 .02 .50 .01

# of items 22 22 22 22

Method

• Participants: 64 (mean age = 22; #F = 47)

• Apparatus:– Dual-Purkinje Eyetracker (Gen 5.5)– 4 characters ≈ 1o of visual angle

• Procedure:– 88 experimental passages– Yes/No comprehension questions on half the trials

WOW!

Results: Fixation Time Measures

• Early– First fixation duration (FFD)– Single fixation duration (SFD)– Gaze duration (GD)

• Later– Next forward-going fixation after target (‘spillover’)– Total Fixation Time (TT)

reject 4%skip 21%

1 fix 63%

2+ fix 12%

Single Fixation Duration: Freq x Pred

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Low High

Predictability

Fix

atio

n D

ura

tio

n (

ms

)

LF

HF

26 ms

9 ms

First Fixation Duration

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270

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330

Low High

Predictability

Fix

atio

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ura

tio

n (

ms)

LF

HF

Gaze Duration

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330

Low High

Predictability

Fix

ati

on

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rati

on

(m

s)

LF

HF

Just then,a smug grincomes overhis face…

Ha! Told you so!

• In reading, words are initially processed parafoveally before they are directly foveated.

• Prior research indicates that both the frequency and predictability of the parafoveal word can influence its subsequent fixation duration.

• Specifically,– HF parafoveal words are subsequently fixated for less

time than LF ones (Inhoff & Rayner, 1986).– HP parafoveal words are subsequently fixated for less

time than LP ones (Balota, Pollatsek, & Rayner, 1985).

Parafoveal Pre-Processing

The sore on Tam-Tam’s rump was swollen.

invisibleboundary

* ** *

* * *

Boundary Technique

The sore on Tam-Tam’s tnam was swollen.

invalid parafoveal preview

…grabbed a bottle of waterwater from a… 1-3




…grabbed a bottle of waterwater from a… 13+

Launch Distance

(Poorly) Simulated Perceptual Span





…grabbed a bottle of waterwater from a… 13+

%Data Contingent on Launch Distance

1-3 (16%)

4-6 (24%)

7-9 (21%)

10-12 (10%)

13+ (5%)

skips (21%)

rejected(4%)

(15%)

(21%)

(17%)

(6%)

(4%)

#items#subjects #conditions per cond # data points

64 x 4 x 22 = 5632

# Data Points by Condition: SFD

0

50

100

150

200

250

300

350

13+ 10-12 7-9 4-6 1-3

Launch Distance (# letters)

# D

ata

Po

ints LF-LP

LF-HP

HF-LP

HF-HP

SFD: Freq x Pred x Launch

200

220

240

260

280

300

1 2 3 4 5 6 7 8

Fix

atio

n D

ura

tio

n (

ms)

LF

HF

Low HighPredictability

7-9


4-6


1-3

Launch Distance from Target (# letters)

• RT studies, in general, find that word frequency and contextual predictability interact.

• Eye movement studies, measuring target word fixation time in normal reading, find that frequency and predictability are additive.

• When the amount of parafoveal preview is manipulated (post-hoc via launch distance), however, different patterns of data emerge.

Summary of Results

Summary of Results

• Specifically,

• Fixation duration vs. RT?– Far condition ≈ RT physically, but not behaviorally– Near condition ≈ RT behaviorally, but not physically

Launch distance Freq Pred FxP

Far (7-9)

Mid (4-6) HFHF

Near (1-3) HFHF,LFLF HFHF<LFLF

• Apparent additive effect of Freq & Pred in reading is comprised of opposing interactive effects.

Conclusions

SFD: Freq x Pred X Launch

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1 2 3 4 5 6 7 8F

ixa

tio

n D

ura

tio

n (

ms

)

LF

HF

LP HP

7-9



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300

Low High

Predictability

Fix

ati

on

Du

rati

on

(m

s)

LF

HF

LP HP

4-6

LP HP

1-3

• Explanation 1: Frequency First

Conclusions


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Low High

Predictability

Fix

atio

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tio

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ms)

LF

HF

• Explanation 2: Floors & Ceilings

Conclusions


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1 2 3 4 5 6 7 8

Fix

atio

n D

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tio

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ms

)

LF

HF

LP HP

7-9


LP HP

4-6

LP HP

1-3

• Launch Site

Conclusions

Used as a tool to capturethe temporal dynamics ofparafoveal processing.

–

Demonstrated sensitivityto the temporal & spatialcontingencies intrinsic toreading.

–

Provides a more fluid ortransitional account ofconcurrent oculomotorand linguistic processing.

–

Thank y’all

• “Parafoveal-on-foveal” effects (oh no!):– When the ease or difficulty in processing a parafoveal

target initially manifests itself on the current, pre-target fixation.

Effects Before the Target?

…grabbed a bottle of waterwater from a…

location of current,pre-target fixation

Fixation Before Target: Freq x Pred

240

250

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270

Low High

Predictability

Fix

atio

n D

ura

tio

n (

ms)

LF

HF

4 ms(marg.)

6 ms (p<.01)

Fixation Before Target: Launch Dist.

200

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300

1 2 3 4 5 6 7 8

Fix

atio

n D

ura

tio

n (

ms)

LF

HF


7-9


4-6


1-3


FFD: Freq x Pred X Launch

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320

1 2 3 4 5 6 7 8

Fix

atio

n D

ura

tio

n (

ms)

LF

HF


7-9


4-6


1-3



200

220

240

260

280

300

320

1 2 3 4 5 6 7 8

Fix

ati

on

Du

rati

on

(m

s)

LF

HF


7-9


4-6


1-3


GD: Freq x Pred X Launch

200

220

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280

300

320

1 2 3 4 5 6 7 8

Fix

atio

n D

ura

tio

n (

ms)

LF

HF


7-9


4-6


1-3


TT: Freq x Pred

290

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Low High

Predictability

Fix

atio

n D

ura

tio

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ms

)

LF

HF

Effects: F1 F2

Freq *** *** Pred *** *** FxP marg n.s.

Probability of Skipping

0.15

0.20

0.25

0.30

Low High

Predictability

Pro

bab

ility

LF

HF

Next Fwd Fix: Freq x Pred

250

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Low High

Predictability

Fix

atio

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ms)

LF

HF

Effects: F1 F2

Freq n.s. n.s. Pred marg. n.s. FxP ** marg.

parafoveal processing influences word frequency & predictability effects on eye movements during...

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