Auditory Word Recognition

8/13/2019 Auditory Word Recognition

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9/8/10 Psyc / Ling / Comm 525 Fall 10

Auditory Word Recognition

Clearly, we use top-down processing

The acoustic signal alone is often just not enough

Record people saying:

Predictable: A stitch in time saves nine.

Unpredictable: The next number will be nine.

The ninespliced out of the predictable context is oftenunintelligible in isolation

So, people use context

How and when???


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Phoneme Restoration

Replace one phoneme in an utterance with noise

If the phoneme is predictable from context, peoplehear the missing sound (e.g., legi*lature)

If tell them a sound has been replaced, theyre notaccurate at identifying which sound it is

Warren & Warren (1970) Stimuli (acoustically identical except for last word)

It was found that the *eel was on the orange.

It was found that the *eel was on the axle.

It was found that the *eel was on the shoe. It was found that the *eel was on the table.

People believed they had heard the phoneme thatmade sense given the final word

Final word canthave influenced what they heard at *eel


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Zwitserlood (1989)(Tests predictions of Cohort Model - Zwitserlood wasMarslen-Wilsons student & this was her dissertation)

Cohort Modelframework

How much information is retrieved about all the

activated cohort members (=competitors)before selection?

How early in word recognition does context

influence processing?


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Possible Timecourse of Context Effects

From Zwitserlood (1989)


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Methods

People heard sentences that ended with a critical word(e.g., kapitein) Critical words had clear competitors before their uniqueness

point(e.g., kapit aal)

At one of several timepoints during the critical word, avisual word that was semantically related to either the

critical word or its competitor (e.g., schipor geld)appeared on screen Task = lexical decision Cross-modal priming paradigm

Use response to target to tap into processing of prime

Early test points intended to determine how early context canrule out inconsistent competitors Test points determined separately for each critical word by

results ofgating study


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Stimuli

Gating study

People heard successively longer fragments of critical words In 3 kinds context Carrier phrase: The next word is kapitein. Neutral context: They mourned the loss of their kapitein. Biasing context: With dampened spirits the men stood around the grave. They

mourned the loss of their kapitein. Control context:The player got the ball and scored the winning goal.

Guessed what the word was

Recognition point= Point in word where everyone identifies it asthe critical word

Often earlier than uniqueness point How much earlier typically depends on degree of contextual constraint

Get to see what competitors are produced before recognition point


7/189/8/10 Psyc / Ling / Comm 525 Fall 10

Visual Probe Positions(for each critical word)

Isolation point= Timepoint in word when the critical word first given as aresponse by a participant & after which its the onlyresponse for that participant (mean across participants)

1. Isolation point in Biasing Context (Mean = 133 msec; lexical access)

2. Isolation point in Neutral Context (Mean = 199 msec; lexical access)

3. Isolation point in Carrier Phrase (Mean = 278 msec; selection)

4. Recognition point in Carrier Phrase (Mean = 410 msec; integration)

Probes= schipor geld



Heres where enough

of word heard to startchoosing target over

competitor

Results

From Zwitserlood (1989)

Probe positions 1 & 2

-Probes related to both

Critical Word & Competitorprimed by hearing some of

Critical word, compared to

Control condition

Probe position 3

- Hear enough word that target

more active than competitor in

Carrier Phrase (= selection)

- Only then does Biasing

Context have an effect

-So, context does not influence

word recognition until enough

bottom-up information to start

selecting word from cohort

133 199 278 410

schip

geld

Heres also where

biasing context firststarts to have effect



Conclusions

The results of this study led to the revision ofthe Cohort Model such that context effects canonly come in relatively late



Allopenna, Magnuson, & Tanenhaus (1998)Tests predictions of TRACE Model

An important difference between Cohort & TRACE models

Difference in degree of constraint provided by word onsetscompared to rest of word is bigger in Cohort Model

Previous work had not found any clear effects of competitorsthat didnt share onsets

Allopenna et al. tested this by including competitors that

shared onsets vs rhymes



Stimulus Words

From Allopenna et al., 1998



Results of running simulations forthese items in TRACE Model

From Allopenna et al., 1998

Rhyme competitorspeakerbecomes

almost as active as

cohort competitor

beetle, though

later of course



Methods

- Instructions:Point to the

-Display contains:-Targetbeaker

-And at least one of:

-Cohort competitorbeetle

-Rhyme competitorspeaker-Unrelated wordcarriage

-Participants wore head-mounted

eyetracker- People tend to look at objects

that are mentioned- especially before reaching for them

- How quickly do they look at the

objects related to the target word?


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Predicted fixation probabilitiesbased on TRACE simulations


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Fixation Probability Results


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Comparison of data to model predictions

Target & Cohort CompetitorTarget & Rhyme Competitor

Model slightly overpredicts fixations to Target & slightly underpredicts fixations to

both Cohort & Rhyme competitors


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Gating Study

TRACE Model Predictions Object choice (pointing) data

- Maybe results of first experiment specifically due to having competitor objects visually present?- What would happen in a task using same display but that emphasizes auditory word onsets?


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Gating StudyFixation & Pointing Results

Model vs Fixation data Model vs Pointing data

- So, its not the presence of the visual object with competitor names that led to theresults in Experiment 1

- Experiment 1 provided the first clear evidence of activation of Rhyme competitors- which lends support to the TRACE Model over the Cohort Model- & which led to further revision of the Cohort Model

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Auditory Word Recognition