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- Lovcevic, Irena, et al.
(author)
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Neural processing of hyper-and hypo-articulated vowels in Infant-Directed Speech
- 2019
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Conference paper (peer-reviewed)abstract
- When addressing infants, adults use a speech register known as infant-directed speech (IDS). Compared to adult-directed speech (ADS), IDS has a number of distinctive acoustic and linguistic features. Vowel hyperarticulation, the expansion of the acoustic space between the corner vowels /i,u,a/, is one feature specifically proposed to facilitate language acquisition processes. Interestingly, the presence of vowel hyperarticulation in IDS appears to be dependent on the infant’s communicative and linguistic needs. Mothers do not hyperarticulate vowels in IDS to infants with hearing loss (Lam & Kitamura, 2010) or infants at-risk for dyslexia (Kalashnikova et al., 2018), indicating that infants’ ability to hear and process speech can influence speakers’ IDS to them. Given the important role of vowel hyperarticulation in early language acquisition, it is of interest to investigate the effects of IDS with hypo-articulated vowels on infants’ early linguistic processing.This study investigated whether there is a neurophysiological difference in the processing of hyper- and hypo-articulated vowels in IDS by comparing the electroencephalographic (EEG) signatures of typical IDS with hyperarticulated vowels (hyper-IDS), IDS that lacks vowel hyperarticulation (hypo-IDS), and ADS in 9 month-old-infants (N = 12). Event-related potentials (ERPs) were recorded while infants listened to familiar words in hyper-IDS, hypo-IDS, and ADS registers. If hyper-IDS facilitates infants’ early lexical processing, we expected it to elicit a different pattern in brain potentials compared to hypo-IDS and ADS.Regarding electrophysiological measures, mean amplitudes were calculated in the 250-500ms time window measured from word onset, since ERP amplitudes in this window have been proposed to reflect increased semantic processing (Kidd et al., 2018; Zangl & Mills, 2007). A Speech (hyper-IDS, hypo-IDS, ADS) x Antpost (frontal, central, parietal, occipital) x Laterality (left, right) ANOVA yielded a main effect of Speech (F(2, 22) = 7.054, p = .004, p2 = .391) and Speech x Antpost x Laterality interaction (F(6, 66) = 2.771, p = .018, p2 = .201), meaning that the factor Speech interacted with topographical factors. Hypo-IDS was found to elicit a broadly distributed negativity compared to hyper-IDS and ADS respectively, which gave rise to more positive amplitudes in the same time window. Taken together, these results suggest a decrease in lexical processing for hypo-IDS.These findings indicate different brain responses to IDS with and without vowel hyperarticulation in early language processing, supporting the assumption that vowel hyperarticulation in IDS influences infants’ early linguistic processing. Given that early brain potentials occurring at 200-500ms have previously been suggested to reflect increased lexical or semantic processing, these findings indicate that infants are sensitive to the specific acoustic qualities of IDS, which facilitate semantic processing (Junge et al., 2014). Importantly, the current findings demonstrate that IDS with hyperarticulated vowels provides infants with a rich linguistic signal. When hyperarticulation is absent, lexical processing appears to be impeded. This is an especially important insight with regard to infants with hearing loss who do not have access to this feature in IDS, but who may instead rely more on other perceptual advantages offered by this register.
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- Lulaci, Tugba, et al.
(author)
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The time course of onset CV coarticulation
- 2022
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In: Proceedings of Fonetik 2022 : Fonetik 2022 - the XXXIIIrd Swedish Phonetics Conference - Fonetik 2022 - the XXXIIIrd Swedish Phonetics Conference. - 0282-6690. ; :XXXIII
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Conference paper (other academic/artistic)abstract
- The study investigates the center of gravity in onset fricatives as a main acoustic feature to assess the relation between vowel pronunciation and coarticulatory spectral characteristics of the onset consonant. /s/- and /f/-initial CV sequences were analyzed with backness, roundedness and height of the vowel as predictors of fricative center of gravity. Results showed that the first 15 ms of an onset fricative could carry predictive cues to the upcoming vowel.
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- Roll, Mikael, et al.
(author)
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Forehearing words : Pre-activation of word endings at word onset
- 2017
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In: Neuroscience Letters. - : Elsevier BV. - 0304-3940. ; 658, s. 57-61
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Journal article (peer-reviewed)abstract
- Occurring at rates up to 6-7 syllables per second, speech perception and understanding involves rapid identification of speech sounds and pre-activation of morphemes and words. Using event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI), we investigated the time-course and neural sources of pre-activation of word endings as participants heard the beginning of unfolding words. ERPs showed a pre-activation negativity (PrAN) for word beginnings (first two segmental phonemes) with few possible completions. PrAN increased gradually as the number of possible completions of word onsets decreased and the lexical frequency of the completions increased. The early brain potential effect for few possible word completions was associated with a blood-oxygen-level-dependent (BOLD) contrast increase in Broca’s area (pars opercularis of the left inferior frontal gyrus) and angular gyrus of the left parietal lobe. We suggest early involvement of the left prefrontal cortex in inhibiting irrelevant left parietal activation during lexical selection. The results further our understanding of the importance of Broca’s area in rapid online pre-activation of words.
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- Roll, Mikael, et al.
(author)
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Phonetic markedness, turning points, and anticipatory attention
- 2011
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In: Fonetik 2011: Speech, Music and Hearing Quarterly Progress and Status Report. - 1104-5787. ; 51, s. 113-116
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Conference paper (other academic/artistic)abstract
- Phonetic markedness regarding linguistically relevant tonal patterns (Accent 2, boundary tones) in Central Swedish is discussed. Both tonal markedness and F0 turning points are assumed to be important cues for anticipatory attention to grammatical structure during speech processing. Empirical evidence from neuro- linguistic and psycholinguistic experiments for the assumed relation between anticipatory attention and marked tonal patterns’ association with Swedish word and clause structures is presented.
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- Roll, Mikael, et al.
(author)
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Pre-activation negativity in language brain potentials
- 2023
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In: ; , s. 64-64
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Conference paper (peer-reviewed)abstract
- The pre-activation negativity (PrAN) is an event-related potential (ERP) component indexing how constraining phonological cues are. It has an early phase (136-200 ms), with sources in the left auditory cortices, and a late phase (200 ms onwards), with sources in Broca’s area. The PrAN has been found for segmental and prosodic cues increasing the certainty about upcoming words, morphemes, grammatical structures, or lexicality. The phonological cues investigated have been Central Swedish, South Swedish, Danish, and English segmental phonemes, Central and South Swedish lexical tone accents, Danish stød, and Central Swedish boundary tones and left-edge boundary tones/initiality accents.
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- Roll, Mikael, et al.
(author)
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Pre-activation negativity (PrAN) : A neural index of predictive strength of phonological cues
- 2023
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In: Laboratory Phonology. - : Open Library of the Humanities. - 1868-6354. ; 14:1, s. 1-28
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Journal article (peer-reviewed)abstract
- We propose that a recently discovered event-related potential (ERP) component—the pre-activation negativity (PrAN)—indexes the predictive strength of phonological cues, including segments, word tones, and sentence-level tones. Specifically, we argue that PrAN is a reflection of the brain’s anticipation of upcoming speech (segments, morphemes, words, and syntactic structures). Findings from a long series of neurolinguistic studies indicate that the effect can be divided into two time windows with different possible brain sources. Between 136 and 200 ms from stimulus onset, it indexes activity mainly in the primary and secondary auditory cortices, reflecting disinhibition of neurons sensitive to the expected acoustic signal, as indicated by the brain regions’ response to predictive certainty rather than sound salience. After ~200 ms, PrAN is related to activity in Broca’s area, possibly reflecting inhibition of irrelevant segments, morphemes, words, and syntactic structures.
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