Spoken word recognition is a critical hub in language that could link age-related declines in hea... more Spoken word recognition is a critical hub in language that could link age-related declines in hearing and cognition. Changes in word recognition across the lifespan have not been established and it is unclear whether any such changes can be accounted for by hearing or domain-general cognition. We used the Visual World Paradigm to examine several indices of the real-time dynamics of word recognition from early adolescence through older adulthood (ages 11 – 78, N = 107). Recognition became more efficient through the 20’s and began to slow in middle age, accompanied by declines in the ability to resolve competition. This suggests a limited age range where listeners are peak performers. This was seen even after accounting for differences in cognition and hearing thresholds. Word recognition may thus be an important marker for early changes to cognition in older adulthood and a mediator between hearing loss, quality of life, and cognitive decline.
Speech unfolds rapidly, and information necessary for phoneme recognition does not arrive simulta... more Speech unfolds rapidly, and information necessary for phoneme recognition does not arrive simultaneously. Listeners process speech incrementally: information is used as soon as it arrives to make partial decisions and anticipate future material. However, fricatives are not processed incrementally: listeners delay lexical access until all cues arrive. Fricatives also contain coarticulation that anticipates upcoming vowels. We examined the timecourse of anticipation, finding that listeners anticipate vowels immediately, but wait several hundred milliseconds for fricative identification. Thus, listeners do not process speech in the order that cues arrive—the dynamics of language processing may be only loosely coupled to the input.
Understanding speech in noise (SiN) is a complex task that recruits multiple cortical subsystems.... more Understanding speech in noise (SiN) is a complex task that recruits multiple cortical subsystems. There is a variance in individuals’ ability to understand SiN that cannot be explained by simple hearing profiles, which suggests that central factors may underlie the variance in SiN ability. Here, we elucidated a few cortical functions involved during a SiN task and their contributions to individual variance using both within- and across-subject approaches. Through our within-subject analysis of source-localized electroencephalography, we investigated how acoustic signal-to-noise ratio (SNR) alters cortical evoked responses to a target word across the speech recognition areas, finding stronger responses in left supramarginal gyrus (SMG, BA40 the dorsal lexicon area) with quieter noise. Through an individual differences approach, we found that listeners show different neural sensitivity to the background noise and target speech, reflected in the amplitude ratio of earlier auditory-cort...
Mixed effects models have become a critical tool in all areas of psychology and allied fields. Th... more Mixed effects models have become a critical tool in all areas of psychology and allied fields. This is due to their ability to account for multiple random factors, and their ability to handle proportional data in repeated measures designs. While substantial research has addressed how to structure fixed effects in such models there is less understanding of appropriate random effects structures. Recent work with linear models suggests the choice of random effects structures affects Type I error in such models (Barr, Levy, Scheepers, & Tily, 2013; Matuschek, Kliegl, Vasishth, Baayen, & Bates, 2017). This has not been examined for between subject effects, which are crucial for many areas of psychology, nor has this been examined in logistic models. Moreover, mixed models expose a number of researcher degrees of freedom: the decision to aggregate data or not, the manner in which degrees of freedom are computed, and what to do when models do not converge. However, the implications of thes...
Infancy : the official journal of the International Society on Infant Studies
Dialogue between conversational partners, including mothers and their children, is precisely time... more Dialogue between conversational partners, including mothers and their children, is precisely timed. The predictability of this timing is important for establishing and maintaining interaction, communication, and learning. This longitudinal study examines changes in the response latency of utterances in dialogue between mothers and their normal hearing and hearing impaired children between 4 and 60 months of age. Mothers and their children showed parallel developmental trends, responding to each other more quickly at older ages. Beyond these age-related group effects, significant dyadic effects were found in which individual children's latencies were related to those of their mothers, and vice versa. Developmental patterns did not significantly differ across hearing status groups, which may reflect the role of early identification and intervention in promoting positive developmental outcomes.
To inform the development of gamified assessments, this study explored how students with or at ri... more To inform the development of gamified assessments, this study explored how students with or at risk for reading difficulties in Grades 6–8 ( N = 202) perceived and interacted with a decoding assessment designed with gamification characteristics. Three data sources enhanced the methodological triangulation: observations and scores from testing, surveys of students’ perceptions, and focus group discussions with a stratified random sample of students ( n = 25). Findings suggest students became immersed in the gamified reading assessment and were motivated by tasks that were challenging but not frustratingly difficult. However, they were dissatisfied with some design features and reported focusing on identifying patterns and gaming strategies rather than on the reading skills being assessed. This suggests students’ expectations of gamified assessments might contribute construct irrelevant variance to the instruments.
A great deal of behavioral evidence suggests that infants can use distributional statistics to le... more A great deal of behavioral evidence suggests that infants can use distributional statistics to learn speech sound categories. Recently, a number of computational approaches have demonstrated the feasibility of statistical learning by showing that the distributional statistics of linguistically-relevant acoustic cues can be learned in an unsupervised way. However, speakers and listeners use a large number of acoustic cues to distinguish phonetic categories, and it is not clear how multiple cues are combined during perception. We propose a model of speech sound category acquisition that learns the distributions of multiple cues that lie along the same dimension and combines them. We demonstrate that the model is able to account for trading relations between cues (an indicator of the size of the effect of each cue) for word-initial voicing contrasts in English.
Previous research on speech perception in both adults and infants has supported the view that con... more Previous research on speech perception in both adults and infants has supported the view that consonants are perceived categorically; that is, listeners are relatively insensitive to variation below the level of the phoneme. More recent work, on the other hand, has shown adults to be systematically sensitive to within category variation (McMurray, Tanenhaus & Aslin, 2002). Additionally, recent evidence suggests that infants are capable of using within-category variation to segment speech and to learn phonetic categories. Here we report two studies of 8-month-old infants, using the head-turn preference procedure, that examine more directly infants ’ sensitivity to within-category variation. Infants were exposed to 80 repetitions of words beginning with either /b / or /p/. After exposure, listening times to tokens of the same category with small variations in VOT were significantly different than to both the originally exposed tokens and to the cross–category-boundary competitors. Thu...
Objectives: The ability to adapt to subtle variation in acoustic input is a necessary skill for s... more Objectives: The ability to adapt to subtle variation in acoustic input is a necessary skill for successful speech perception. Cochlear implant (CI) users tend to show speech perception benefits from the maintenance of their residual acoustic hearing. However, previous studies often compare CI users in different listening conditions within-subjects (i.e., in their typical Acoustic + Electric configuration compared to Acoustic-only or Electric-only configurations) and comparisons among different groups of CI users do not always reflect an Acoustic + Electric benefit. Existing work suggests that CI users with residual acoustic hearing perform similarly to Electric-only listeners on phonetic voicing contrasts and unexpectedly poorer with fricative contrasts which have little energy in the range of the Acoustic + Electric listeners’ acoustic hearing. To further investigate how residual acoustic hearing impacts sensitivity to phonetic ambiguity, we examined whether device configuration, a...
Words are fundamental to language, linking sound, articulation and spelling to meaning and syntax... more Words are fundamental to language, linking sound, articulation and spelling to meaning and syntax; and lexical deficits are core to communicative disorders. Work in language acquisition commonly asks how lexical knowledge – the sound pattern and meaning of words – is acquired. This is insufficient to account for skilled behavior. Sophisticated real-time processes must decode the sound pattern of words and interpret them appropriately. This paper reviews work that overcome this gap by using sensitive real-time measures of language processing (eye-tracking in the Visual World Paradigm) along with highly familiar words with school age children. This work reveals that the development of word recognition skills can be characterized by differences in the rate by which decisions unfold in the lexical system (the activation rate) and that this develops extremely slowly – through adolescence. In contrast language disorders can be linked to differences in the ultimate degree to which competin...
Understanding spoken language requires analysis of the rapidly unfolding speech signal at multipl... more Understanding spoken language requires analysis of the rapidly unfolding speech signal at multiple levels: acoustic, phonological, and semantic. However, there is not yet a comprehensive picture of how these levels relate. We recorded electroencephalography (EEG) while listeners (N=31) heard sentences in which we manipulated acoustic ambiguity (e.g., a bees/peas continuum) and sentential expectations (e.g., Honey is made by bees). EEG was analyzed with a mixed effects model over time to quantify how language processing cascades proceed on a millisecond-by-millisecond basis. Our results indicate: (1) perceptual processing and memory for fine-grained acoustics is preserved in brain activity for up to 900 msec; (2) contextual analysis begins early and is graded with respect to the acoustic signal; and (3) top-down predictions influence perceptual processing in some cases, however, these predictions are available simultaneously with the veridical signal. These mechanistic insights provi...
The Visual World Paradigm (VWP) is a powerful experimental paradigm for language. Listeners respo... more The Visual World Paradigm (VWP) is a powerful experimental paradigm for language. Listeners respond to speech in a “visual world” consisting of potential referents of the speech. Fixations to these referents provides insight into the preliminary states of language processing as decisions unfold. The VWP has become the dominant paradigm in psycholinguistics and extended to every level of language, development, and disorders. Part of its impact is the impressive data visualizations which reveal the millisecond-by-millisecond timecourse of processing, and advances have been made in developing new analyses that precisely characterize this timecourse. However, all theoretical and statistical approaches make the tacit assumption that the timecourse of fixations is closely related to the underlying activation in the system. It is unclear if this assumption holds given the sequential nature of fixations, and their long refractory period. I investigated this assumption with a series of simul...
Spoken word recognition is a critical hub in language that could link age-related declines in hea... more Spoken word recognition is a critical hub in language that could link age-related declines in hearing and cognition. Changes in word recognition across the lifespan have not been established and it is unclear whether any such changes can be accounted for by hearing or domain-general cognition. We used the Visual World Paradigm to examine several indices of the real-time dynamics of word recognition from early adolescence through older adulthood (ages 11 – 78, N = 107). Recognition became more efficient through the 20’s and began to slow in middle age, accompanied by declines in the ability to resolve competition. This suggests a limited age range where listeners are peak performers. This was seen even after accounting for differences in cognition and hearing thresholds. Word recognition may thus be an important marker for early changes to cognition in older adulthood and a mediator between hearing loss, quality of life, and cognitive decline.
Speech unfolds rapidly, and information necessary for phoneme recognition does not arrive simulta... more Speech unfolds rapidly, and information necessary for phoneme recognition does not arrive simultaneously. Listeners process speech incrementally: information is used as soon as it arrives to make partial decisions and anticipate future material. However, fricatives are not processed incrementally: listeners delay lexical access until all cues arrive. Fricatives also contain coarticulation that anticipates upcoming vowels. We examined the timecourse of anticipation, finding that listeners anticipate vowels immediately, but wait several hundred milliseconds for fricative identification. Thus, listeners do not process speech in the order that cues arrive—the dynamics of language processing may be only loosely coupled to the input.
Understanding speech in noise (SiN) is a complex task that recruits multiple cortical subsystems.... more Understanding speech in noise (SiN) is a complex task that recruits multiple cortical subsystems. There is a variance in individuals’ ability to understand SiN that cannot be explained by simple hearing profiles, which suggests that central factors may underlie the variance in SiN ability. Here, we elucidated a few cortical functions involved during a SiN task and their contributions to individual variance using both within- and across-subject approaches. Through our within-subject analysis of source-localized electroencephalography, we investigated how acoustic signal-to-noise ratio (SNR) alters cortical evoked responses to a target word across the speech recognition areas, finding stronger responses in left supramarginal gyrus (SMG, BA40 the dorsal lexicon area) with quieter noise. Through an individual differences approach, we found that listeners show different neural sensitivity to the background noise and target speech, reflected in the amplitude ratio of earlier auditory-cort...
Mixed effects models have become a critical tool in all areas of psychology and allied fields. Th... more Mixed effects models have become a critical tool in all areas of psychology and allied fields. This is due to their ability to account for multiple random factors, and their ability to handle proportional data in repeated measures designs. While substantial research has addressed how to structure fixed effects in such models there is less understanding of appropriate random effects structures. Recent work with linear models suggests the choice of random effects structures affects Type I error in such models (Barr, Levy, Scheepers, & Tily, 2013; Matuschek, Kliegl, Vasishth, Baayen, & Bates, 2017). This has not been examined for between subject effects, which are crucial for many areas of psychology, nor has this been examined in logistic models. Moreover, mixed models expose a number of researcher degrees of freedom: the decision to aggregate data or not, the manner in which degrees of freedom are computed, and what to do when models do not converge. However, the implications of thes...
Infancy : the official journal of the International Society on Infant Studies
Dialogue between conversational partners, including mothers and their children, is precisely time... more Dialogue between conversational partners, including mothers and their children, is precisely timed. The predictability of this timing is important for establishing and maintaining interaction, communication, and learning. This longitudinal study examines changes in the response latency of utterances in dialogue between mothers and their normal hearing and hearing impaired children between 4 and 60 months of age. Mothers and their children showed parallel developmental trends, responding to each other more quickly at older ages. Beyond these age-related group effects, significant dyadic effects were found in which individual children's latencies were related to those of their mothers, and vice versa. Developmental patterns did not significantly differ across hearing status groups, which may reflect the role of early identification and intervention in promoting positive developmental outcomes.
To inform the development of gamified assessments, this study explored how students with or at ri... more To inform the development of gamified assessments, this study explored how students with or at risk for reading difficulties in Grades 6–8 ( N = 202) perceived and interacted with a decoding assessment designed with gamification characteristics. Three data sources enhanced the methodological triangulation: observations and scores from testing, surveys of students’ perceptions, and focus group discussions with a stratified random sample of students ( n = 25). Findings suggest students became immersed in the gamified reading assessment and were motivated by tasks that were challenging but not frustratingly difficult. However, they were dissatisfied with some design features and reported focusing on identifying patterns and gaming strategies rather than on the reading skills being assessed. This suggests students’ expectations of gamified assessments might contribute construct irrelevant variance to the instruments.
A great deal of behavioral evidence suggests that infants can use distributional statistics to le... more A great deal of behavioral evidence suggests that infants can use distributional statistics to learn speech sound categories. Recently, a number of computational approaches have demonstrated the feasibility of statistical learning by showing that the distributional statistics of linguistically-relevant acoustic cues can be learned in an unsupervised way. However, speakers and listeners use a large number of acoustic cues to distinguish phonetic categories, and it is not clear how multiple cues are combined during perception. We propose a model of speech sound category acquisition that learns the distributions of multiple cues that lie along the same dimension and combines them. We demonstrate that the model is able to account for trading relations between cues (an indicator of the size of the effect of each cue) for word-initial voicing contrasts in English.
Previous research on speech perception in both adults and infants has supported the view that con... more Previous research on speech perception in both adults and infants has supported the view that consonants are perceived categorically; that is, listeners are relatively insensitive to variation below the level of the phoneme. More recent work, on the other hand, has shown adults to be systematically sensitive to within category variation (McMurray, Tanenhaus & Aslin, 2002). Additionally, recent evidence suggests that infants are capable of using within-category variation to segment speech and to learn phonetic categories. Here we report two studies of 8-month-old infants, using the head-turn preference procedure, that examine more directly infants ’ sensitivity to within-category variation. Infants were exposed to 80 repetitions of words beginning with either /b / or /p/. After exposure, listening times to tokens of the same category with small variations in VOT were significantly different than to both the originally exposed tokens and to the cross–category-boundary competitors. Thu...
Objectives: The ability to adapt to subtle variation in acoustic input is a necessary skill for s... more Objectives: The ability to adapt to subtle variation in acoustic input is a necessary skill for successful speech perception. Cochlear implant (CI) users tend to show speech perception benefits from the maintenance of their residual acoustic hearing. However, previous studies often compare CI users in different listening conditions within-subjects (i.e., in their typical Acoustic + Electric configuration compared to Acoustic-only or Electric-only configurations) and comparisons among different groups of CI users do not always reflect an Acoustic + Electric benefit. Existing work suggests that CI users with residual acoustic hearing perform similarly to Electric-only listeners on phonetic voicing contrasts and unexpectedly poorer with fricative contrasts which have little energy in the range of the Acoustic + Electric listeners’ acoustic hearing. To further investigate how residual acoustic hearing impacts sensitivity to phonetic ambiguity, we examined whether device configuration, a...
Words are fundamental to language, linking sound, articulation and spelling to meaning and syntax... more Words are fundamental to language, linking sound, articulation and spelling to meaning and syntax; and lexical deficits are core to communicative disorders. Work in language acquisition commonly asks how lexical knowledge – the sound pattern and meaning of words – is acquired. This is insufficient to account for skilled behavior. Sophisticated real-time processes must decode the sound pattern of words and interpret them appropriately. This paper reviews work that overcome this gap by using sensitive real-time measures of language processing (eye-tracking in the Visual World Paradigm) along with highly familiar words with school age children. This work reveals that the development of word recognition skills can be characterized by differences in the rate by which decisions unfold in the lexical system (the activation rate) and that this develops extremely slowly – through adolescence. In contrast language disorders can be linked to differences in the ultimate degree to which competin...
Understanding spoken language requires analysis of the rapidly unfolding speech signal at multipl... more Understanding spoken language requires analysis of the rapidly unfolding speech signal at multiple levels: acoustic, phonological, and semantic. However, there is not yet a comprehensive picture of how these levels relate. We recorded electroencephalography (EEG) while listeners (N=31) heard sentences in which we manipulated acoustic ambiguity (e.g., a bees/peas continuum) and sentential expectations (e.g., Honey is made by bees). EEG was analyzed with a mixed effects model over time to quantify how language processing cascades proceed on a millisecond-by-millisecond basis. Our results indicate: (1) perceptual processing and memory for fine-grained acoustics is preserved in brain activity for up to 900 msec; (2) contextual analysis begins early and is graded with respect to the acoustic signal; and (3) top-down predictions influence perceptual processing in some cases, however, these predictions are available simultaneously with the veridical signal. These mechanistic insights provi...
The Visual World Paradigm (VWP) is a powerful experimental paradigm for language. Listeners respo... more The Visual World Paradigm (VWP) is a powerful experimental paradigm for language. Listeners respond to speech in a “visual world” consisting of potential referents of the speech. Fixations to these referents provides insight into the preliminary states of language processing as decisions unfold. The VWP has become the dominant paradigm in psycholinguistics and extended to every level of language, development, and disorders. Part of its impact is the impressive data visualizations which reveal the millisecond-by-millisecond timecourse of processing, and advances have been made in developing new analyses that precisely characterize this timecourse. However, all theoretical and statistical approaches make the tacit assumption that the timecourse of fixations is closely related to the underlying activation in the system. It is unclear if this assumption holds given the sequential nature of fixations, and their long refractory period. I investigated this assumption with a series of simul...
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Papers by Bob McMurray