Acoustic analyses and perceptual data on anticipatory labial coarticulation in adults and children

The present study investigated anticipatory labial coarticulation in the speech of adults and children. CV syllables, [s], [t], and [d] before [i] and [u], were produced by an adult male speaker and a female child speaker age 3 years 6 months. Each syllable was computer‐edited to include only the noise‐excited portion of fricative‐vowel stimuli and only the aperiodic portion of stop‐vowel stimuli. LPC spectra were computed for each excised segment. Analyses of the effect of the following vowel on the spectral peak associated with the second formant frequency and on the characteristic spectral prominence for each consonant were performed. Perceptual data were obtained by presenting the aperiodic consonantal segments to subjects who were instructed to identify in a forced choice paradigm the following vowel [i] or [u]. Both the acoustic and perceptual data show strong coarticulatory effects for adults and the absence of such coarticulations in the speech stimuli of the child. The results are discussed in terms of the articulatory and perceptual aspects of coarticulation in language learning

Acoustic analyses and perceptual data on anticipatory labial coarticulation in adults and children

This is the published version, also available here: http://dx.doi.org/10.1121/1.394917.The present study investigated anticipatory labial coarticulation in the speech of adults and children. CV syllables, composed of [s], [t], and [d] before [i] and [u], were produced by four adult speakers and eight child speakers aged 3–7 years. Each stimulus was computer edited to include only the aperiodic portion of fricative‐vowel and stop‐vowel syllables. LPC spectra were then computed for each excised segment. Analyses of the effect of the following vowel on the spectral peak associated with the second formant frequency and on the characteristic spectral prominence for each consonant were performed. Perceptual data were obtained by presenting the aperiodic consonantal segments to subjects who were instructed to identify the following vowel as [i] or [u]. Both the acoustic and the perceptual data show strong coarticulatory effects for the adults and comparable, although less consistent, coarticulation in the speech stimuli of the children. The results are discussed in terms of the articulatory and perceptual aspects of coarticulation in language learning

How Do French–English Bilinguals Pull Verb Particle Constructions Off? Factors Influencing Second Language Processing of Unfamiliar Structures at the Syntax-Semantics Interface

An important challenge in bilingualism research is to understand the mechanisms underlying sentence processing in a second language and whether they are comparable to those underlying native processing. Here, we focus on verb-particle constructions (VPCs) that are among the most difficult elements to acquire in L2 English. The verb and the particle form a unit, which often has a non-compositional meaning (e.g., look up or chew out), making the combined structure semantically opaque. However, bilinguals with higher levels of English proficiency can develop a good knowledge of the semantic properties of VPCs (Blais and Gonnerman, 2013). A second difficulty is that in a sentence context, the particle can be shifted after the direct object of the verb (e.g., The professor looked it up). The processing is more challenging when the object is long (e.g., The professor looked the student’s last name up). This shifted structure favors syntactic processing at the expense of VPC semantic processing. We sought to determine whether or not bilinguals’ reading time (RT) patterns would be similar to those observed for native monolinguals (Gonnerman and Hayes, 2005) when reading VPCs in sentential contexts. French–English bilinguals were tested for English language proficiency, working memory and explicit VPC semantic knowledge. During a self-paced reading task, participants read 78 sentences with VPCs that varied according to parameters that influence native speakers’ reading dynamics: verb-particle transparency, particle adjacency and length of the object noun phrase (NP; 2, 3, or 5 words). RTs in a critical region that included verbs, NPs and particles were measured. Results revealed that RTs were modulated by participants’ English proficiency, with higher proficiency associated with shorter RTs. Examining participants’ explicit semantic knowledge of VPCs and working memory, only readers with more native-like knowledge of VPCs and a high working memory presented RT patterns that were similar to those of monolinguals. Therefore, given the necessary lexical and computational resources, bilingual processing of novel structures at the syntax-semantics interface follows the principles influencing native processing. The findings are in keeping with theories that postulate similar representations and processing in L1 and L2 modulated by processing difficulty

Contextual Influences on Phonetic Identification in Aphasia: The Effects of Speaking Rate and Semantic Bias

Two experiments examined the influence of context on stop-consonant voicing identification in fluent and nonfluent aphasic patients and normal controls. Listeners were required to label the initial stop in a target word varying along a voice onset time (VOT) continuum as either voiced or voiceless ([b]/[p] or [d]/[t]). Target stimuli were presented in sentence contexts in which the rate of speech of the sentence context (Experiment 1) or the semantic bias of the context (Experiment 2) was manipulated. The results revealed that all subject groups were sensitive to the contextual influences, although the extent of the context effects varied somewhat across groups and across experiments. In addition, a number of patients in both the fluent and nonfluent aphasic groups could not consistently identify even endpoint stimuli, confirming phonetic categorization impairments previously shown in such individuals. Results are discussed with respect to the potential reliance by aphasic patients on higher level context to compensate for phonetic perception deficits

Sensitivity to sub-syllabic constituents in brain-damaged patients: evidence from word games

Two experiments were conducted to examine whether left- (LHD) and right-hemisphere-damaged (RHD) patients exhibit sensitivity to sub-syllabic constituents (i.e., onsets and codas) in the generation of nonwords, using a word games paradigm adapted from Treiman (1983). Four groups of individuals (including LHD fluent and nonfluent aphasic patients, RHD patients and normal controls) were trained to add syllables to monosyllabic CVC nonwords either after the initial consonant (Experiment 1) or prior to the final consonant (Experiment 2) to create bisyllabic nonwords. Experimental stimuli consisting of CCVC or CVCC nonwords tested whether participants would preserve or split the onset and coda constituents in producing the novel bisyllabic nonwords. Results revealed that the majority of subjects demonstrated sensitivity to the sub-syllabic constituents, preserving the onsets and codas. The fluent aphasic patients exhibited a greater than normal tendency to split the onset and coda constituents; however, the small number of individuals in that group whose data met inclusion criteria limits the conclusions that may be drawn from these findings. The results are discussed in relation to theories of phonological deficits in aphasia

Age differences in the influence of metrical structure on phonetic identification

Two phonetic identification experiments were conducted with two groups of participants: a young adult group and an older adult group. In Experiment 1, subjects were required to make voiced–voiceless decisions for initial alveolar stop consonants to stimuli along two voice onset time (VOT) continua—one ranging from “di’gress” to “ti’gress” and the other from “’digress” to “’tigress” (i.e., in one continuum, the voiced endpoint was consistent with the word’s stress pattern while in the other continuum, the voiceless endpoint was consistent with the word’s stress pattern). Results revealed that both groups of participants were influenced by the stress pattern of the stimuli, but stress seemed to override VOT cues for a large number of the older individuals. To confirm that the effect was not simply due to a lexical influence, a follow-up experiment utilized two word–nonword continua (“diamond–tiamond” and “diming–timing”) to examine the magnitude of lexical effects in these subject groups. Typical lexical status effects emerged for both young and older adults which were smaller than the effects of stress pattern found in Experiment 1. The findings are discussed with respect to the role of prosodic context in language processing in aging

Word recognition in individuals with left and right hemisphere damage: The role of lexical stress

Lexical stress patterns appear to be important in word recognition processes in normal individuals. The present investigation employed a lexical decision task to assess whether left (LHD) and right hemisphere damaged (RHD) patients are similarly sensitive to stress patterns in lexical access. The results confirmed that individuals without brain damage are influenced by stress patterns, as indicated by increased lexical decision latencies to incorrectly stressed word and nonword stimuli. The data for the LHD patients revealed an effect of stress for real word targets only, whereas the reaction time data for the RHD patients as a group showed no significant influence of stress pattern. However, there was a great deal of individual variability in performance. The latency and error rate findings suggest that LHD patients and non-brain-damaged individuals are both sensitive to lexical stress in word recognition, but the LHD patients are more likely to treat incorrectly stressed items as nonwords. The results are discussed in relation to theories of the hemispheric lateralization of prosodic processing and the role of lexical stress in word recognition

Acoustic analysis of intra-word syllabic timing relations in anterior aphasia

A study was conducted to explore intra-word syllabic timing relations in anterior, non-fluent aphasic patients. Ten sets of three words of increasing length (e.g. “sleep,” “sleepy,” sleepiness”) were elicited from four non-fluent aphasic subjects. Acoustic analyses revealed that, overall, the aphasic patients produced monosyllabic root words with longer durations than those root words embedded in multisyllabic utterances. This general pattern was consistent with that for normal subjects reported in the literature (Lehiste 1972). However, the aphasic patients exhibited anomalous results for root word durations in the three-syllable condition. That is, root word durations were increased in the three-syllable compared to the two-syllable condition — a pattern which contrasts with that of normal subjects. Results are discussed in relation to theories which attempt to characterize the speech production deficit in anterior aphasia

Cross-Language Competition is Modulated by Individual Differences in Executive Function: An Aging Study

Background: Accumulating evidence from empirical and clinical studies has shown evidence suggesting that lexical selection is more difficult when there is greater cross-language competition. These studies further suggest that higher cognitive mechanisms, particularly inhibitory control, may play a crucial role in the regulation of languages in the bilingual brain. An important implication of this finding is that the process of lexical selection in a bilingual context may be particularly difficult for older adults for whom a vast body of literature has demonstrated a decline in cognitive functions required for language processing and production. However, benefits in executive functions (EF) conferred by life-long bilingualism may protect against age-related difficulties in language skills (1). Here, we sought to investigate whether older adults resolved within- and cross-language lexical competition differently from younger adults and whether factors such as word status (cognate and non-cognate word processing) and individual differences in domain-general executive control modulated cross-language interference resolution. Methods: In a picture-word interference paradigm, French-English bilingual younger and older adults named cognate and non-cognate pictures in English while ignoring within- and cross-language auditory distractor words (at varying SOAs). The distractors exhibited three different relations to the cognate target picture (Cactus): semantic (Thorn or Épine), phonological (Canvas or Cahier (notebook)) and unrelated control (Soap or Meuble (furniture)). An additional target-distractor relation was included for the non-cognate target pictures: phonological relation to the translation (Gâteau) of the target (Cake) – (Garden or Garçon (boy)). Additionally, to evaluate whether cross-language interference is modulated by individual differences in executive control, a battery of EF tests was administered. To further imply causality to EF and bilingual lexical selection, we employed high-frequency rTMS (10 Hz) to facilitate the region of the brain involved in EF (DLPFC) and measured post-stimulation RT and accuracy scores. Results: Our results correspond with previous findings of picture word interference effects in both younger and older adults. Pictures with cognate names were named faster than pictures with non-cognate names across SOA and distractor conditions. Additionally, both groups demonstrated greater within-language semantic interference and phonological facilitation effects and marginal between-language effects. As expected, older adults had more difficulty suppressing cross-language competitors than younger adults. Overall, older adults also demonstrated less efficient inhibitory control compared to younger adults measured by the Stroop and Simon tasks indicating that declining inhibitory control skills in healthy older bilinguals may underlie increased lexical competition. Of note, for our hypothesis regarding domain-general executive control, we expected to see decreased response times in EF and picture naming tasks post TMS stimulation, particularly in individuals with decreased EF skills as a consequence of aging, supporting the notion that individual differences in EF modulate bilingual lexical selection