Reading Ambiguous Words

Reading Ambiguous Words

Sereno, O’Donnell, & Rayner

University of University ofGlasgow Massachusetts

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

Models of Lexical Ambiguity Resolution

• Modular position– Access is exhaustive: All meanings of ambiguous words are

automatically accessed; context cannot directly affect lexical processing, but instead operates on the output of the lexical processor to select the appropriate sense.

• Interactive position– Access is selective: Context guides access towards the

appropriate sense of an ambiguous word; while both senses may be initially activated, only the contextually appropriate sense is fully accessed.

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.

So, when is access?

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

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

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

• If you can track frequency, you can track lexical access...

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

553 ms490 ms

259 ms275 ms

280 ms293 ms

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

EM studies of lexical ambiguity

• Compare fixation time on an ambiguous word to a control word across different contexts.

Context Ambiguous Control

Neutral Robin peered over at the _____ ... bank edge

Biasing The mud was deep along the _____ ... bank edge

• Critical factors that affect fixation time

Fixationtime

>

=

(1) Context

(2) Meaning instantiated

(3) Type of amb word

Factors identified from EM studies

Biasing = disambiguation before targetNeutral = disambiguation after target

Dominant (Dom)Subordinate (Sub)

Biased (polarized): Dom >> SubBalanced: Dom ≥ Sub

(1) Context

(2) Meaning instantiated

(3) Type of amb word

Factors identified from EM studies

Biasing = disambiguation before targetNeutral = disambiguation after target

Dominant (Dom)Subordinate (Sub)

Biased (polarized): Dom >> SubBalanced: Dom ≥ Sub

BANK

Dominant:“money”

Subordinate:“river”

(1) Context

(2) Meaning instantiated

(3) Type of amb word

Factors identified from EM studies

Biasing = disambiguation before targetNeutral = disambiguation after target

Dominant (Dom)Subordinate (Sub)

Biased (polarized): Dom >> SubBalanced: Dom ≥ Sub

Biased (polarised): Dom >> Sub

Balanced: Dom ≥ Sub

Why is BANK so slow?

• BANK is a biased ambiguous word (Dom>>Sub), and the prior biasing context supports its Sub sense.

• Shouldn’t a biasing context facilitate word recognition?

Context Ambiguous Control

Neutral Robin peered over at the _____ ... bank edge

Biasing The mud was deep along the _____ ... bank edge>

=

Why is BANK so slow?

• Interactive: – Lexical processing is slowed because the Sub sense is

equivalent to a low frequency (LF) word meaning.

• Modular: – Post-lexical processing (serial) is slowed in biasing context

because integration is only successful half the time (at most).

Context Ambiguous Control

Neutral Robin peered over at the _____ ... bank edge

Biasing The mud was deep along the _____ ... bank edge>

=

Why are the others faster?

• Why is EDGE so fast?– It’s a HF word.

• Why is Neutral BANK so fast?– Only strong, Dom sense is accessed & it fits (neutral) context.

>

=

Context Ambiguous Control

Neutral Robin peered over at the _____ ... bank edge

Biasing The mud was deep along the _____ ... bank edge

What about the CONTROL word?• In almost all EM ambiguity studies, the unambiguous control

word is chosen to match the overall word-form frequency of the ambiguous target.

• For biased ambiguous words (Dom>>Sub), this typically results in control words that are high frequency (HF) words.

• A more appropriate control might be one matched to the meaning frequency of the ambiguous word’s instantiated Sub sense – a low frequency (LF) word.

Ambiguous (Sub) The mud was deep along the bank ...

Word form = HF The mud was deep along the edge ...

Word meaning = LF The mud was deep along the brim ...

BANK

ambiguous unambiguous controls

BRIMEDGE

“river”

“money” “edge”

“brim”

MEANING

FORM

Dom

Sub

HF

LFFOFO RR MM

MM EAEA NN II NNGG

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 inconsistentSereno (1995) x xBinder & Morris (1995) x inconsistentBinder & Rayner (1998) x xBinder & Rayner (1999) x xRayner, Binder, & Duffy (1999) x xWiley & Rayner (2000) x xKambe, Rayner, & Duffy (2001) x inconsistentBinder (2003) x inconsistent

Contextsentence paragraph

Control wordHF LF amb

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

Sereno, O’Donnell, & Rayner

(Sub / Dom)

Kambe et al. (2001)

Global Mike Tyson had just arrived in town on a promotional tour.

After she was robbed, Mary decided to buy an attack dog.

2 ‘fillers’When the community found out, many of them were very angry. Others were not sure how they felt.

Mary wanted something to protect her so when she saw an ad for aboxer/puppy in the local paper, she bought it and immediately felt much safer.

Local + target

Consistent“dog” “dog”

Inconsistent“fighter” “dog”

(Sub )

Kambe et al. (2001)

Sam was out of shape andneeded to join a gym.

Sam’s pet died last week andhe wanted a new companion.

He spent a great deal of time reviewinghis options. He even went to talk to otherpeople to get their advice.

Sam decided to go to a kennel wherehe bought a boxer/puppy that he knew he would like to take home.

Consistent“dog” “dog”

Inconsistent“fighter” “dog”

(Sub / Dom)Global

2 ‘fillers’

Local + target(Sub )

Kambe et al. (2001)

Context Global Local Gaze Duration (ms)

Consistent Sub Sub Amb (303) > HF (286)

Inconsistent Dom Sub Amb (304) > HF (291)

Sereno, O’Donnell, & Rayner:Changes to Kambe et al.

1 Only use Consistent (global=local=SUB) contexts.

2 Remove 2 internal “filler” sentences that occur between global and local sentences.

3 Add word meaning (LF) control word.

4 Create new paragraph to accommodate additional control word for counter-balancing purposes.

Stimuli: Example 1

Step 1: Only Consistent versions

After she was robbed, Mary decided to buy an attack dog. When the community found out, many of them were very angry. Others were not sure how they felt. Mary wanted something to protect her so when she saw an ad for a boxer/puppy in the local paper, she bought it and immediately felt much safer.

Sam’s pet died last week and he wanted a new companion. He spent a great deal of time reviewing his options. He even went to talk to other people to get their advice. Sam decided to go to a kennel where he bought a boxer/puppy that he knew he would like to take home.

Stimuli: Example 1

Step 2: Remove internal ‘filler’ sentences

After she was robbed, Mary decided to buy an attack dog. When the community found out, many of them were very angry. Others were not sure how they felt. Mary wanted something to protect her so when she saw an ad for a boxer/puppy in the local paper, she bought it and immediately felt much safer.

Sam’s pet died last week and he wanted a new companion. He spent a great deal of time reviewing his options. He even went to talk to other people to get their advice. Sam decided to go to a kennel where he bought a boxer/puppy that he knew he would like to take home.

Stimuli: Example 1

Step 3: Add word meaning (LF) control

After she was robbed, Mary decided to buy an attack dog. Mary wanted something to protect her so when she saw an ad for a boxer/puppy/husky in the local paper, she bought it and immediately felt much safer.

Sam’s pet died last week and he wanted a new companion. Sam decided to go to a kennel where he bought a boxer/puppy/husky that he knew he would like to take home.

Stimuli: Example 1

Step 4: New passage for counter-balancing

After she was robbed, Mary decided to buy an attack dog. Mary wanted something to protect her so when she saw an ad for a boxer/puppy/husky in the local paper, she bought it and immediately felt much safer.

Sam’s pet died last week and he wanted a new companion. Sam decided to go to a kennel where he bought a boxer/puppy/husky that he knew he would like to take home.

“I don’t want a cat!” screamed Tara. Her parents were devastated. How could they have been mistaken? She liked dogs. They went out the next day and brought home a little boxer/puppy/husky and hoped their Tara would approve.

Stimuli: Example 2

Step 1: Only Consistent versions

Colleen was tormented by her sins. She began to feel as if she were losing control of her life. She did not want to feel worse than she already did. She knelt down in the church after putting on the habit/cross that all of the novices were required to wear within the convent walls.

Although Peggy had a deep sense of faith she was troubled. Recently, when she went to the doctor, he told her that her health was deteriorating. She was extremely upset by the news. Peggy decided to become a nun and wear a habit/cross in order to symbolize her devotion to religious life.

Stimuli: Example 2

Step 2: Remove internal ‘filler’ sentences

Colleen was tormented by her sins. She began to feel as if she were losing control of her life. She did not want to feel worse than she already did. She knelt down in the church after putting on the habit/cross that all of the novices were required to wear within the convent walls.

Although Peggy had a deep sense of faith she was troubled. Recently, when she went to the doctor, he told her that her health was deteriorating. She was extremely upset by the news. Peggy decided to become a nun and wear a habit/cross in order to symbolize her devotion to religious life.

Stimuli: Example 2

Step 3: Add word meaning (LF) control

Colleen was tormented by her sins. She knelt down in the church after putting on the habit/cross/shawl that all of the novices were required to wear within the convent walls.

Although Peggy had a deep sense of faith she was troubled. Peggy decided to become a nun and wear a habit/cross/shawl in order to symbolize her devotion to religious life.

Stimuli: Example 2

Step 4: New passage for counter-balancing

Colleen was tormented by her sins. She knelt down in the church after putting on the habit/cross/shawl that all of the novices were required to wear within the convent walls.

Although Peggy had a deep sense of faith she was troubled. Peggy decided to become a nun and wear a habit/cross/shawl in order to symbolize her devotion to religious life.

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/cross/shawl and carried a stake.

• Stimuli:

Amb HF(form) LF(Sub)frequency 65 64 5length 4.96 4.96 4.92# items 24 24 24

• Subjects: 45

• Design:– 3 passages for each matched set of 3 targets (x 24 sets = 72 total items)– Each subject saw all 3 targets, each in different passages– 3 subject conditions by rotating 3 targets through 3 different passages– 15 Ss in each of the 3 possible subject conditions

Sereno, O’Donnell, & Rayner:Specifications

Sub = 6%Dom = 90%

Single Fixation Duration

250

260

270

280

290

1

Word Type

Fixation Time (ms)

AmbHFLF

Amb HF LF

Fixation Time (ms)

240

260

280

300

320

340

360

FFD SFD GD TT Nxt +2wd

AmbHFLF

“target” “spillover”

Conclusions – 1• Ambiguous words (with prior context supporting the

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

• The present data support a hybrid model in which both the prior context and meaning frequency of the instantiated sense affect lexical access.– Reordered Access Model (Duffy, Morris, & Rayner, 1988).– 2-Stage Modular-Interactive (Potter, Moryadas, Abrams, & Noel, 1993)– Independent Activation Model (Twilley & Dixon, 2000)

• The present data do not provide clear support for either a strong modular or strong interactive account.– Both predict (for different reasons) increased difficulty than that observed.

Conclusions – 2

• Bottom line: Future lexical ambiguity studies should use both word-form (HF) & word-meaning (LF) controls.

• The dual nature of an ambiguous words means that the characteristics of the control word need to be seriously considered.

• A LF meaning control can cast light on the contextual constraint of meaning activation.