Reading Ambiguous Words

Sara Sereno

in collaboration withPaddy O’Donnell

Why ambiguous words?

• Ambiguous words have 1 form and 2 meanings:

• Is only the context-relevant meaning selectively accessed, or, are all meanings accessed (regardless of context) with selection occurring at a later, post-lexical integration stage?

• The timing of contextual constraint - early or late - has implications for the architecture of language processing...

• Understanding how ambiguous words are processed tells us about how words in general are processed.

CRICKET = or cf.

Distributed hierarchical visual processing in the primatelexical human

features

letters

word forms

meanings

higher-levelsemantics

syntax

Distributed hierarchical visual processing in the primatelexical human

Measurement

• In order to specify when higher-level processes affect lower-level processes, one needs to accurately measure the processes of interest.

• In word recognition, perceptual and cognitive events occur on the millisecond scale.

+ =?

(Sereno & Rayner, Trends in Cognitive Sciences, 2003)

But, when is access?

• A word frequency effect [ HF < LF ] is used as a marker or index of successful word recognition or lexical access.

The sore on Tam-Tam’s was swollen.(HF) back(LF) rump

• The word frequency effect represents the differential response to commonly used high-frequency (HF) words vs. low-frequency (LF) words that occur much less often:

• But, what does frequency have to do with ambiguity?

BANK

Dominant:“money”

Subordinate:“river”

Biased (polarised): Dom >> Sub

Balanced: Dom ≥ Sub

BANK

ambiguous unambiguous controls

BRIMEDGE

“river”

“money” “edge”

“brim”

MEANING

FORM

Dom

Sub

HF

LF

EM ambiguity studiesDuffy & Rayner (1986) x xDuffy, Morris, & Rayner (1988) x xRayner & Frazier (1989) x xSereno, Pacht, & Rayner (1992) x x xDopkins, Morris, & Rayner (1992) x xRayner, Pacht, & Duffy (1994) x - switchSereno (1995) x xBinder & Morris (1995) x - switchBinder & Rayner (1998) x xBinder & Rayner (1999) x xRayner, Binder, & Duffy (1999) x xWiley & Rayner (2000) x xKambe, Rayner, & Duffy (2001) x - switchBinder (2003) x - switch

Contextsentence paragraph

Control wordHF LF amb

ERP studySereno, Brewer, & O’Donnell (2003) x x x

EM ambiguity studiesDuffy & Rayner (1986) x xDuffy, Morris, & Rayner (1988) x xRayner & Frazier (1989) x xSereno, Pacht, & Rayner (1992) x x xDopkins, Morris, & Rayner (1992) x xRayner, Pacht, & Duffy (1994) x - switchSereno (1995) x xBinder & Morris (1995) x - switchBinder & Rayner (1998) x xBinder & Rayner (1999) x xRayner, Binder, & Duffy (1999) x xWiley & Rayner (2000) x xKambe, Rayner, & Duffy (2001) x - switchBinder (2003) x - switch

Contextsentence paragraph

Control wordHF LF amb

ERP studySereno, Brewer, & O’Donnell (2003) x x x

Sereno, O’Donnell, & Rayner

The moon cast an eerie light as Sister Margaret hurried up the unlit road. She had heard tales about the vampire. Although she did not believe them, Sister Margaret was still cautious. So when she was out alone at night, she wore her habit and carried a stake.

The moon cast an eerie light as Sister Margaret hurried up the unlit road. She had heard tales about the vampire. Although she did not believe them, Sister Margaret was still cautious. So when she was out alone at night, she wore her habit and carried a stake.

habitcrossshawl

AmbHF (form)LF (meaning)

Single Fixation Duration

250

260

270

280

290

1

Word Type

Fixation Time (ms)

AmbHFLF

Amb HF LF

Conclusions• Ambiguous words (with prior context supporting the

weak, subordinate sense) are simultaneously:HF forms fastLF meanings slow

• The present data support a top-down account, with early (lexical) selection of the contextually appropriate sense.

• A strict bottom-up account, with later (post-lexical selection), predicts increased difficulty (both meanings would need to be integrated at least half of the time).

• Future lexical ambiguity studies should use both the word-form (HF) and word-meaning (LF) controls.

Fixation Time

240

260

280

300

320

340

360

FFD SFD GD TT Nxt +2wd

AmbHFLF

(Sereno & Rayner, Trends in Cognitive Sciences, 2003)

Emotion words

Valence

Arousal

+ ve

– ve

Lo Hi

peace love

bored fire

Neutral controls: hotel, farm

MEASURE

Normal reading

TASK

fixation duration (as well aslocation and sequence of EMs)

TIME RES.

GOOD

POORhemodynamic imaging: fMRI, PET

electromagnetic imaging: EEG, MEG

various word tasks

ms-by-ms

seconds

various word tasks

Standard word recognition paradigms (± priming, ± masking):

naming

categorisationlexical decision RT

~500 ms~600 ms~800 ms

~250 ms

MEASURE

Normal reading

TASK

fixation duration (as well aslocation and sequence of EMs)

TIME RES.

GOOD

POORhemodynamic imaging: fMRI, PET

electromagnetic imaging: EEG, MEG

various word tasks

ms-by-ms

seconds

various word tasks

Standard word recognition paradigms (± priming, ± masking):

naming

categorisationlexical decision RT

~500 ms~600 ms~800 ms

~250 ms

HF vs. LF activation

0

0.5

1

1.5

2

2.5

3

3.5

4

1 2 3 4 5 6 7 8 9 10

Time

Activation

HF

LF

t