1. 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 nine spliced out of the predictable context is often unintelligible in isolation
So, people use context
How and when???
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Psyc / Ling / Comm 525 Fall 10

2. Phoneme Restoration Replace one phoneme in an utterance with noise
If the phoneme is predictable from context, people “hear” the missing sound (e.g., legi*lature)
If tell them a sound has been replaced, they’re not accurate 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 that made sense given the final word
Final word can’t have influenced what they heard at *eel
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Psyc / Ling / Comm 525 Fall 10

3. Cohort Model framework
Zwitserlood (1989) (Tests predictions of Cohort Model - Zwitserlood was Marslen-Wilson’s student & this was her dissertation)
Cohort Model framework
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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Psyc / Ling / Comm 525 Fall 10

4. Possible Timecourse of Context Effects
From Zwitserlood (1989)
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5. 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, a visual word that was semantically related to either the critical word or its competitor (e.g., schip or 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 can rule out inconsistent competitors
Test points determined separately for each critical word by results of gating study
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Psyc / Ling / Comm 525 Fall 10

6. 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 as the 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
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Psyc / Ling / Comm 525 Fall 10

7. Visual Probe Positions (for each critical word)
Isolation point = Timepoint in word when the critical word first given as a response by a participant & after which it’s the only response for that participant (mean across participants)
Isolation point in Biasing Context (Mean = 133 msec; lexical access)
Isolation point in Neutral Context (Mean = 199 msec; lexical access)
Isolation point in Carrier Phrase (Mean = 278 msec; selection)
4. Recognition point in Carrier Phrase (Mean = 410 msec; integration)
Probes = schip or geld
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8. Results Probe positions 1 & 2 Probes related to both
Critical Word & Competitor
primed 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
Here’s also where biasing context first starts to have effect
Here’s where enough
of word heard to start
choosing target over
competitor
schip
geld
From Zwitserlood (1989)
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9. Conclusions
The results of this study led to the revision of the Cohort Model such that context effects can only come in relatively late
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10. Allopenna, Magnuson, & Tanenhaus (1998) Tests predictions of TRACE Model
An important difference between Cohort & TRACE models
Difference in degree of constraint provided by word onsets compared to rest of word is bigger in Cohort Model
Previous work had not found any clear effects of competitors that didn’t share onsets
Allopenna et al. tested this by including competitors that shared onsets vs rhymes
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11. Stimulus Words 9/8/10 Psyc / Ling / Comm 525 Fall 10
From Allopenna et al., 1998
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12. Results of running simulations for these items in TRACE Model
Rhyme competitor
“speaker” becomes
almost as active as
cohort competitor
“beetle”, though
later of course
From Allopenna et al., 1998
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13. Methods - Instructions: “Point to the …” Display contains:
Target beaker
And at least one of:
Cohort competitor beetle
Rhyme competitor speaker
Unrelated word carriage
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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14. Predicted fixation probabilities based on TRACE simulations
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15. Fixation Probability Results
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16. Comparison of data to model predictions
Target & Cohort Competitor
Target & Rhyme Competitor
Model slightly overpredicts fixations to Target & slightly underpredicts fixations to
both Cohort & Rhyme competitors
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17. Gating Study Object choice (pointing) data TRACE Model Predictions
- 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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Psyc / Ling / Comm 525 Fall 10

18. Gating Study – Fixation & Pointing Results
Model vs Fixation data
Model vs Pointing data
- So, it’s not the presence of the visual object with competitor names that led to the
results 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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