The Time-Course of Lexical Activation
and Individual Differences inJapanese Two-Character Word Recognition

Koji Miwa †, Gary Libben ‡ & R. Harald Baayen †† University of Alberta, ‡ University of Calgary

Canada

MOPROC, Turku, Finland
June 16, 2009

Japanese Kanji Logography• An auditorily simplex word
can be morphographicallycomplex in Japanese.
• The majority of Japanese“simplex” words arecomplex in this sense.
• How are two-characterwords recognized ?

Purely orthographic morpheme

2Lexical Predictors
Whole Word
Whole Word Token Freq (3,620),
Google Doc Freq (49,400,000)

Kanji Character
Kanji Neighbours (149) , Kanji Token Freq (15,854)
Kanji AoA (2) , Kanji Homophones (11)Radical
Radical Combinability (60)
Radical Token Freq (493,077)

Character Strokes
Kanji Strokes (14), Radical Strokes (7)3LDT with Eye-Tracking• Participants- 15 native Japanese speakers in Canada• Materials- 708 two-character words- 708 nonwords• Procedure- 472 words in one session * 3 sessions- Fixation point manipulations(left, central, right)
4

Observed Eye Movements
What do these different eye-movement patterns reveal
about morphographic two-character word recognition ?

5Lexical Predictors
Whole Word
Whole Word Token Freq (3,620),
Google Doc Freq (49,400,000)

Kanji Character
Kanji Neighbours (149) , Kanji Token Freq (15,854)
Kanji AoA (2) , Kanji Homophones (11)Radical
Radical Combinability (60)
Radical Token Freq (493,077)

Character Strokes
Kanji Strokes (14), Radical Strokes (7)6Stroke Effects• Blue line
= Fixation on the given character• Red line
= Fixation on the other character• Mirror-image effects for the left andright characters• The fixated character’s strokes:- are not predictive at the 1st fixation.
- become inhibitory at later fixations(the more complex the currently
fixated character, the longer it takes
to process it).

7

Stroke Effects• Blue line
= Fixation on the given character• Red line
= Fixation on the other character• The non-fixated character’s strokes:- are facilitatory until 2nd fixation.
- reflect anticipation of further
required processing (You lookshorter at the currently fixatedcharacter if you know that there
is more complex work ahead on
the other character8Semantic Radical Frequency Effects• Blue line
= Fixation on the given characterns• Red line
= Fixation on the other character• At the 1st fixation, the rightns

character’s semantic radical token
frequency is facilitatory.
• At the 2nd fixation, this facilitatoryns

ns

effect remains only when the othercharacter is fixated.
• When the right character is fixated,the effect becomes inhibitory.

9Character Frequency Effects• Blue line
= Fixation on the given character• Red line
= Fixation on the other character• Mirror-image effects for the left andright characters• At the 1st fixation, the left frequency isfacilitatory, and the right is inhibitory.
• Competition with its facilitatory
semantic radical effects• Hyponym (character) vs. hypernym(semantic radical)

10

Character Frequency Effects• Blue line
= Fixation on the given character• Red line
= Fixation on the other character• At the 2nd and 3rd fixations,the fixated character revealed
facilitatory effects.
• The other character emerged as acompetitor with inhibitory effects.

11Given the Radical and Character
Frequency Effects …
① 1st fixation on the head (right ) character reflects:- Facilitatory effects of semantic radical frequency- Inhibitory effects of character frequency② 2nd fixation on the head (right) character reflects- Inhibitory effects of semantic racial frequency- Facilitatory effects of character frequency
Reflects semantic interpretation:① The general category (the head radical) is probably dominant first.
② Then the specific category (the head character) becomesdominant and remains dominant until the end.

12

Whole Word Frequency Effects• Whole word frequency coded by- Written token frequency in anewspaper for a 14-year period and- Google document frequency(dispersion)• Both of these effects were observed
already at the 1st fixation.
(c.f. Kuperman et al. , 2008)• Magnitude of the frequency effects
increase with each successive fixation.
13

Individual Differences(2nd & 3rd Fixation Durations)• How long the readers had been awayfrom Japan influenced their word
recognition process.
• At the 2nd fixation, whole word frequency
is particularly predictive for newcomers toCanada.
• At the 3rd fixation, the right character’sfrequency is particularly predictive fornewcomers to Canada.

14

Individual Differences(Response Times)• Those speakers of Japanese who newly
arrived in Canada respond more slowly towords with a right character learned late.
• Those speakers of Japanese who have
lived in Canada for many years, and are
subject to language attrition, show
increasingly reduced effects of AoA, andincreasing effects of Google document
frequency

15

Summary
1st Fixation (Exploration)
 Finding out where the information is.
 Establishing the general semantic category.

2nd Fixation (Competition)
 Joint-competitive processing of the head and the modifier.
 Establishing the head category.

3rd Fixation (Wrap-up)
 finalizing the joint interpretation of modifier and head(largest whole word frequency effect) finalizing, perhaps verifying, the fixated character(without competition from the other character)16

Summary
1st Fixation (Exploration)
 Finding out where the good food is.

2nd Fixation (Competition)
 competition between the two sources of food3rd Fixation (Wrap-up)
 Finishing the meal.
17

Thank You
Correspondence
Koji Miwa

Email: kmiwa@ualberta.ca

This research was supported by a Major Collaborative Research Initiative Grant(#412-2001-1009) from the Social Sciences and Humanities Research Council ofCanada to Gary Libben (Director), Gonia Jarema, Eva Kehayia, Bruce Derwing, andLori Buchanan (Co-investigators).

18

Not a simple feed-forward process
Features

Radicals Characters

WordFeatures

Fix.1

Radicals

Fix.2

Characters

Fix.3

Word19

Response Times

20

What is “Length of stay in Canada” ?

21