Tuan Lam | Loyola University New Orleans (original) (raw)
Papers by Tuan Lam
Discourse Processes, 2021
ABSTRACT Although it is clear that unaccented referring expressions are associated with given inf... more ABSTRACT Although it is clear that unaccented referring expressions are associated with given information in a discourse, it is less clear what aspects of givenness are relevant. We examine whether listeners’ expectation of givenness depends on repetition of a referring expression or on contextual evocation of a referent. The results from two visual world eye-tracking experiments suggest that for interpretation, listeners associated reduced prominence with a repeated referring expression. Listeners expect previously evoked referents to be candidates for reduced referring expressions only when they are referred to with the exact same referential form. The data also suggest that when referents are referred to with different referential forms across utterances, accenting facilitates linking those forms for co-reference.
Journal of Speech, Language, and Hearing Research, 2018
Purpose Understanding speech often involves processing input from multiple modalities. The availa... more Purpose Understanding speech often involves processing input from multiple modalities. The availability of visual information may make auditory input less critical for comprehension. This study examines whether the auditory system is sensitive to the presence of complementary sources of input when exerting top-down control over the amplification of speech stimuli. Method Auditory gain in the cochlea was assessed by monitoring spontaneous otoacoustic emissions (SOAEs), which are by-products of the amplification process. SOAEs were recorded while 32 participants (23 women, nine men; M age = 21.13) identified speech sounds such as “ba” and “ga.” The speech sounds were presented either alone or with complementary visual input, as well as in quiet or with 6-talker babble. Results Analyses revealed that there was a greater reduction in the amplification of noisy auditory stimuli compared with quiet. This reduced amplification may aid in the perception of speech by improving the signal-to-...
Brain sciences, Jan 11, 2018
Can experience change perception? Here, we examine whether language experience shapes the way ind... more Can experience change perception? Here, we examine whether language experience shapes the way individuals process auditory and visual information. We used the McGurk effect—the discovery that when people hear a speech sound (e.g., “ba”) and see a conflicting lip movement (e.g., “ga”), they recognize it as a completely new sound (e.g., “da”). This finding suggests that the brain fuses input across auditory and visual modalities demonstrates that what we hear is profoundly influenced by what we see. We find that cross-modal integration is affected by language background, with bilinguals experiencing the McGurk effect more than monolinguals. This increased reliance on the visual channel is not due to decreased language proficiency, as the effect was observed even among highly proficient bilinguals. Instead, we propose that the challenges of learning and monitoring multiple languages have lasting consequences for how individuals process auditory...
Frontiers in neuroscience, 2018
Auditory sensation is often thought of as a bottom-up process, yet the brain exerts top-down cont... more Auditory sensation is often thought of as a bottom-up process, yet the brain exerts top-down control to affect how and what we hear. We report the discovery that the magnitude of top-down influence varies across individuals as a result of differences in linguistic background and executive function. Participants were 32 normal-hearing individuals (23 female) varying in language background (11 English monolinguals, 10 Korean-English late bilinguals, and 11 Korean-English early bilinguals), as well as cognitive abilities (working memory, cognitive control). To assess efferent control over inner ear function, participants were presented with speech-sounds (e.g., /ba/, /pa/) in one ear while spontaneous otoacoustic emissions (SOAEs) were measured in the contralateral ear. SOAEs are associated with the amplification of sound in the cochlea, and can be used as an index of top-down efferent activity. Individuals with bilingual experience and those with better cognitive control experienced l...
Applied Linguistics, 2015
PsycEXTRA Dataset, 2014
Switch-language repetition Same-language repetition Cue to use English Describe shrinking event C... more Switch-language repetition Same-language repetition Cue to use English Describe shrinking event Cue to use Korean Describe flashing event Cue to use English Describe shrinking event Cue to use English Describe flashing event Bilingual Type English Proficiency Mean (SD) Korean Proficiency Mean (SD) Balanced proficiency (N=16) 9.41 (0.82) 9.41 (0.61) Korean-dominant (N=15) 7.73 (1.01) 9.83 (0.31) English-dominant (N=10) 9.80 (0.48) 7.85 (0.71
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2014
Journal of Memory and Language, 2015
Journal of Memory and Language
In natural conversation, speakers often mention the same referents multiple times. While repeated... more In natural conversation, speakers often mention the same referents multiple times. While repeated referents are produced with less prominence than non-repeated referents, it is unclear whether prominence reduction is due to repetition of concepts, words, or a com- bination of the two. In the current study, we dissociate these sources of repetition by exam- ining bilingual speakers, who have more than one word for the same concept across their two languages. Three groups of Korean–English bilinguals (balanced, English-dominant, Korean-dominant) performed an event description task involving repetition of referents within a single language (i.e., repetition of word and concept) or across languages (i.e., rep- etition of concept only). While balanced bilinguals reduced prominence both within and across languages, unbalanced bilinguals only reduced prominence when repetition occurred within a language. These patterns suggest that the degree to which words and concepts are linked within a speaker’s language system determines the source of repetition reduction.
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2014
Repeated words are produced with reduced acoustic prominence compared to words that are new to a ... more Repeated words are produced with reduced acoustic prominence compared to words that are new to a discourse. Although these effects are often attributed to priming in the production system, the locus of the effect within the production system remains unresolved because in natural speech, repetition often involves repetition of referents and lexical items simultaneously.
Memory & Cognition, 2010
The repetition and the predictability of a word in a conversation are two factors that are believ... more The repetition and the predictability of a word in a conversation are two factors that are believed to affect whether it is emphasized: Predictable, repeated words are less acoustically prominent than unpredictable, new words. However, because predictability and repetition are correlated, it is unclear whether speakers lengthen unpredictable words to facilitate comprehension or whether this lengthening is the result of difficulties in accessing a new (nonrepeated) lexical item. In this study, we investigated the relationship between acoustic prominence, repetition, and predictability in a description task. In Experiment 1, we found that repeated referents are produced with reduced prominence, even when these referents are unexpected. In Experiment 2, we found that predictability and repetition both have independent effects on duration and intensity. However, word duration was primarily determined by repetition, and intensity was primarily determined by predictability. The results are most consistent with an account in which multiple cognitive factors influence the acoustic prominence of a word.
Conference Presentations by Tuan Lam
In an object naming study, Lam & Watson (2010) found that predictability and repetition have inde... more In an object naming study, Lam & Watson (2010) found that predictability and repetition have independent effects on how prominently a word is produced in a discourse. Repeated words are produced with shorter duration whereas words with low predictability are produced with greater intensity. Lam & Watson (2010) argue that different cognitive processes underlie the two effects. Reduction is the result of lexical priming while increased intensity results from marking information status. These findings are consistent with Watson’s (2010) multiple source theory: acoustic prominence is best understood as the product of multiple cognitive processes. This theory makes a strong prediction about the nature of prominence across languages: prominence linked to planning (e.g. repetition reduction) should be universal while prominence linked to marking information status may vary more freely.
In this study, we attempt to replicate Lam & Watson’s (2010) finding in Korean. It has been argued that F0 is the most important acoustic correlate to prominence in Korean, whereas in English, intensity, F0, and duration are important (Jun, 1993). Despite these differences, repetition should still lead to shorter durations in Korean. In contrast, effects of predictability on the acoustic signal may vary across the two languages.
We used the same methodology as Lam & Watson (2010) with native Korean speakers. There were two factors: repetition and predictability. On each trial, participants were shown a 3x4 array of 12 images. Their task was to describe a shrinking and a flashing event that occurred in succession in each trial. The critical word for acoustic analysis was the noun in the second utterance. On repeated noun trials, the same object shrank and then flashed. On non-repeated trials, one object shrank and then another object flashed (See Example 1). To manipulate predictability, a circle cued the noun of the second event before it flashed. Exactly 11/12ths of the time, the cue correctly signaled the object involved in the second target. The rest of the time a different object flashed. This resulted in four conditions: repeated/expected, repeated/unexpected, non-repeated/expected, non-repeated/unexpected.
We analyzed duration, intensity, and F0. All analyses were conducted using multilevel linear regression. As in Lam & Watson (2010) repeated mention led to reduced duration (p<0.001). Additionally, repeated mention led to reduced maximum F0 (p<0.05). However, unlike Lam & Watson, predictability did not lead to reduced intensity. Instead predictable words were produced with longer duration than less predictable words (p<0.01).
As in English, repetition led to shorter durations in Korean, suggesting that repetition reduction is the result of priming. However, predictable words were produced with longer durations, perhaps revealing a cross-linguistic difference in how discourse status is realized within the two languages. Nonetheless, this data supports Lam & Watson’s (2010) claim that reduction is the result of priming processes (not predictability), and that multiple factors independently contribute to acoustic prominence.
Example 1:
Non-repeated: 참새가 작아진다 … 의자가 깜빡인다
(bird is shrinking … chair is flashing)
Repeated: 의자가 작아진다 … 의자가 깜빡인다
(chair is shrinking … chair is flashing)
Reference:
Jun, Sun-Ah (1993) The Phonetics and Phonology of Korean Prosody. Unpublished Ph.D. dissertation. The Ohio State University, Columbus, Ohio.
Lam, T. Q. & Watson, D. G. (2010). Repetition is easy: Why repeated referents have reduced prominence. Memory & Cognition, 38(8), 1137-1146.
In natural conversation, speakers often mention the same referents multiple times over the course... more In natural conversation, speakers often mention the same referents multiple times over the course of a conversation, and prior research has demonstrated that previously mentioned referents are produced with less acoustic prominence compared to previously unmentioned referents. However, it is unclear whether this effect is due to repetition of word-forms, repetition of concepts, or a combination of both word-form and concept repetition. In this study, we examined the effect of concept repetition in code-switching Korean-English bilinguals to determine whether word-form repetition is required for reduction. Balanced and unbalanced bilinguals performed an event description task involving repetition of referents both within and across languages. In balanced bilinguals, concept repetition led to prominence reduction both within and across languages, whereas in unbalanced bilinguals, only repetition within languages led to prominence reduction. This pattern suggests that the internal structure of a speaker’s language system determines whether or not conceptual repetition can influence reduction.
Discourse Processes, 2021
ABSTRACT Although it is clear that unaccented referring expressions are associated with given inf... more ABSTRACT Although it is clear that unaccented referring expressions are associated with given information in a discourse, it is less clear what aspects of givenness are relevant. We examine whether listeners’ expectation of givenness depends on repetition of a referring expression or on contextual evocation of a referent. The results from two visual world eye-tracking experiments suggest that for interpretation, listeners associated reduced prominence with a repeated referring expression. Listeners expect previously evoked referents to be candidates for reduced referring expressions only when they are referred to with the exact same referential form. The data also suggest that when referents are referred to with different referential forms across utterances, accenting facilitates linking those forms for co-reference.
Journal of Speech, Language, and Hearing Research, 2018
Purpose Understanding speech often involves processing input from multiple modalities. The availa... more Purpose Understanding speech often involves processing input from multiple modalities. The availability of visual information may make auditory input less critical for comprehension. This study examines whether the auditory system is sensitive to the presence of complementary sources of input when exerting top-down control over the amplification of speech stimuli. Method Auditory gain in the cochlea was assessed by monitoring spontaneous otoacoustic emissions (SOAEs), which are by-products of the amplification process. SOAEs were recorded while 32 participants (23 women, nine men; M age = 21.13) identified speech sounds such as “ba” and “ga.” The speech sounds were presented either alone or with complementary visual input, as well as in quiet or with 6-talker babble. Results Analyses revealed that there was a greater reduction in the amplification of noisy auditory stimuli compared with quiet. This reduced amplification may aid in the perception of speech by improving the signal-to-...
Brain sciences, Jan 11, 2018
Can experience change perception? Here, we examine whether language experience shapes the way ind... more Can experience change perception? Here, we examine whether language experience shapes the way individuals process auditory and visual information. We used the McGurk effect—the discovery that when people hear a speech sound (e.g., “ba”) and see a conflicting lip movement (e.g., “ga”), they recognize it as a completely new sound (e.g., “da”). This finding suggests that the brain fuses input across auditory and visual modalities demonstrates that what we hear is profoundly influenced by what we see. We find that cross-modal integration is affected by language background, with bilinguals experiencing the McGurk effect more than monolinguals. This increased reliance on the visual channel is not due to decreased language proficiency, as the effect was observed even among highly proficient bilinguals. Instead, we propose that the challenges of learning and monitoring multiple languages have lasting consequences for how individuals process auditory...
Frontiers in neuroscience, 2018
Auditory sensation is often thought of as a bottom-up process, yet the brain exerts top-down cont... more Auditory sensation is often thought of as a bottom-up process, yet the brain exerts top-down control to affect how and what we hear. We report the discovery that the magnitude of top-down influence varies across individuals as a result of differences in linguistic background and executive function. Participants were 32 normal-hearing individuals (23 female) varying in language background (11 English monolinguals, 10 Korean-English late bilinguals, and 11 Korean-English early bilinguals), as well as cognitive abilities (working memory, cognitive control). To assess efferent control over inner ear function, participants were presented with speech-sounds (e.g., /ba/, /pa/) in one ear while spontaneous otoacoustic emissions (SOAEs) were measured in the contralateral ear. SOAEs are associated with the amplification of sound in the cochlea, and can be used as an index of top-down efferent activity. Individuals with bilingual experience and those with better cognitive control experienced l...
Applied Linguistics, 2015
PsycEXTRA Dataset, 2014
Switch-language repetition Same-language repetition Cue to use English Describe shrinking event C... more Switch-language repetition Same-language repetition Cue to use English Describe shrinking event Cue to use Korean Describe flashing event Cue to use English Describe shrinking event Cue to use English Describe flashing event Bilingual Type English Proficiency Mean (SD) Korean Proficiency Mean (SD) Balanced proficiency (N=16) 9.41 (0.82) 9.41 (0.61) Korean-dominant (N=15) 7.73 (1.01) 9.83 (0.31) English-dominant (N=10) 9.80 (0.48) 7.85 (0.71
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2014
Journal of Memory and Language, 2015
Journal of Memory and Language
In natural conversation, speakers often mention the same referents multiple times. While repeated... more In natural conversation, speakers often mention the same referents multiple times. While repeated referents are produced with less prominence than non-repeated referents, it is unclear whether prominence reduction is due to repetition of concepts, words, or a com- bination of the two. In the current study, we dissociate these sources of repetition by exam- ining bilingual speakers, who have more than one word for the same concept across their two languages. Three groups of Korean–English bilinguals (balanced, English-dominant, Korean-dominant) performed an event description task involving repetition of referents within a single language (i.e., repetition of word and concept) or across languages (i.e., rep- etition of concept only). While balanced bilinguals reduced prominence both within and across languages, unbalanced bilinguals only reduced prominence when repetition occurred within a language. These patterns suggest that the degree to which words and concepts are linked within a speaker’s language system determines the source of repetition reduction.
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2014
Repeated words are produced with reduced acoustic prominence compared to words that are new to a ... more Repeated words are produced with reduced acoustic prominence compared to words that are new to a discourse. Although these effects are often attributed to priming in the production system, the locus of the effect within the production system remains unresolved because in natural speech, repetition often involves repetition of referents and lexical items simultaneously.
Memory & Cognition, 2010
The repetition and the predictability of a word in a conversation are two factors that are believ... more The repetition and the predictability of a word in a conversation are two factors that are believed to affect whether it is emphasized: Predictable, repeated words are less acoustically prominent than unpredictable, new words. However, because predictability and repetition are correlated, it is unclear whether speakers lengthen unpredictable words to facilitate comprehension or whether this lengthening is the result of difficulties in accessing a new (nonrepeated) lexical item. In this study, we investigated the relationship between acoustic prominence, repetition, and predictability in a description task. In Experiment 1, we found that repeated referents are produced with reduced prominence, even when these referents are unexpected. In Experiment 2, we found that predictability and repetition both have independent effects on duration and intensity. However, word duration was primarily determined by repetition, and intensity was primarily determined by predictability. The results are most consistent with an account in which multiple cognitive factors influence the acoustic prominence of a word.
In an object naming study, Lam & Watson (2010) found that predictability and repetition have inde... more In an object naming study, Lam & Watson (2010) found that predictability and repetition have independent effects on how prominently a word is produced in a discourse. Repeated words are produced with shorter duration whereas words with low predictability are produced with greater intensity. Lam & Watson (2010) argue that different cognitive processes underlie the two effects. Reduction is the result of lexical priming while increased intensity results from marking information status. These findings are consistent with Watson’s (2010) multiple source theory: acoustic prominence is best understood as the product of multiple cognitive processes. This theory makes a strong prediction about the nature of prominence across languages: prominence linked to planning (e.g. repetition reduction) should be universal while prominence linked to marking information status may vary more freely.
In this study, we attempt to replicate Lam & Watson’s (2010) finding in Korean. It has been argued that F0 is the most important acoustic correlate to prominence in Korean, whereas in English, intensity, F0, and duration are important (Jun, 1993). Despite these differences, repetition should still lead to shorter durations in Korean. In contrast, effects of predictability on the acoustic signal may vary across the two languages.
We used the same methodology as Lam & Watson (2010) with native Korean speakers. There were two factors: repetition and predictability. On each trial, participants were shown a 3x4 array of 12 images. Their task was to describe a shrinking and a flashing event that occurred in succession in each trial. The critical word for acoustic analysis was the noun in the second utterance. On repeated noun trials, the same object shrank and then flashed. On non-repeated trials, one object shrank and then another object flashed (See Example 1). To manipulate predictability, a circle cued the noun of the second event before it flashed. Exactly 11/12ths of the time, the cue correctly signaled the object involved in the second target. The rest of the time a different object flashed. This resulted in four conditions: repeated/expected, repeated/unexpected, non-repeated/expected, non-repeated/unexpected.
We analyzed duration, intensity, and F0. All analyses were conducted using multilevel linear regression. As in Lam & Watson (2010) repeated mention led to reduced duration (p<0.001). Additionally, repeated mention led to reduced maximum F0 (p<0.05). However, unlike Lam & Watson, predictability did not lead to reduced intensity. Instead predictable words were produced with longer duration than less predictable words (p<0.01).
As in English, repetition led to shorter durations in Korean, suggesting that repetition reduction is the result of priming. However, predictable words were produced with longer durations, perhaps revealing a cross-linguistic difference in how discourse status is realized within the two languages. Nonetheless, this data supports Lam & Watson’s (2010) claim that reduction is the result of priming processes (not predictability), and that multiple factors independently contribute to acoustic prominence.
Example 1:
Non-repeated: 참새가 작아진다 … 의자가 깜빡인다
(bird is shrinking … chair is flashing)
Repeated: 의자가 작아진다 … 의자가 깜빡인다
(chair is shrinking … chair is flashing)
Reference:
Jun, Sun-Ah (1993) The Phonetics and Phonology of Korean Prosody. Unpublished Ph.D. dissertation. The Ohio State University, Columbus, Ohio.
Lam, T. Q. & Watson, D. G. (2010). Repetition is easy: Why repeated referents have reduced prominence. Memory & Cognition, 38(8), 1137-1146.
In natural conversation, speakers often mention the same referents multiple times over the course... more In natural conversation, speakers often mention the same referents multiple times over the course of a conversation, and prior research has demonstrated that previously mentioned referents are produced with less acoustic prominence compared to previously unmentioned referents. However, it is unclear whether this effect is due to repetition of word-forms, repetition of concepts, or a combination of both word-form and concept repetition. In this study, we examined the effect of concept repetition in code-switching Korean-English bilinguals to determine whether word-form repetition is required for reduction. Balanced and unbalanced bilinguals performed an event description task involving repetition of referents both within and across languages. In balanced bilinguals, concept repetition led to prominence reduction both within and across languages, whereas in unbalanced bilinguals, only repetition within languages led to prominence reduction. This pattern suggests that the internal structure of a speaker’s language system determines whether or not conceptual repetition can influence reduction.