Gait change in tongue movement

During locomotion, humans switch gaits from walking to running, and horses from walking to trotting to cantering to galloping, as they increase their movement rate. It is unknown whether gait change leading to a wider movement rate range is limited to locomotive-type behaviours, or instead is a general property of any rate-varying motor system. The tongue during speech provides a motor system that can address this gap. In controlled speech experiments, using phrases containing complex tongue-movement sequences, we demonstrate distinct gaits in tongue movement at different speech rates. As speakers widen their tongue-front displacement range, they gain access to wider speech-rate ranges. At the widest displacement ranges, speakers also produce categorically different patterns for their slowest and fastest speech. Speakers with the narrowest tongue-front displacement ranges show one stable speech-gait pattern, and speakers with widest ranges show two. Critical fluctuation analysis of tongue motion over the time-course of speech revealed these speakers used greater effort at the beginning of phrases—such end-state-comfort effects indicate speech planning. Based on these findings, we expect that categorical motion solutions may emerge in any motor system, providing that system with access to wider movement-rate ranges.

A Speech Planning Account of Guarani Grammatical Borrowings in Paraguayan Spanish

Previous studies view the use of Guarani grammatical morphemes in Paraguayan Spanish simply as grammatical borrowings (if one focuses on the morphosyntactic status of mixed forms) or as an ill-defined “interference”. But so far there has been no examination of the bilingual planning mechanisms that license and constrain these language mixes. In this paper, I explore the idea that the emergence of grammatical borrowings can be explained by message conceptualization procedures that are influenced by asymmetries in each language’s cognitive dominance. This work thus contributes to our understanding of language contact by applying what we know about language processing and utterance planning to explaining the outcomes observed in language mixing. In so doing, I hope to facilitate a tighter integration between the psycholinguistic planning and language contact literatures.

Do Cross-Language Script Differences Enable Bilinguals to Function Selectively When Speaking in One Language Alone?

The present study examined the role of script in bilingual speech planning by comparing the performance of same and different-script bilinguals. Spanish-English bilinguals (Experiment 1) and Japanese-English bilinguals (Experiment 2) performed a picture-word interference task in which they were asked to name a picture of an object in English, their second language, while ignoring a visual distractor word in Spanish or Japanese, their first language. Results replicated the general pattern seen in previous bilingual picture-word interference studies for the same-script, Spanish-English bilinguals but not for the different-script, Japanese-English bilinguals. Both groups showed translation facilitation, whereas only Spanish-English bilinguals demonstrated semantic interference, phonological facilitation, and phono-translation facilitation. These results suggest that when the script of the language not in use is present in the task, bilinguals appear to exploit the perceptual difference as a language cue to direct lexical access to the intended language earlier in the process of speech planning.

Variation isn’t that hard: Morphosyntactic choice does not predict production difficulty

The following paper explores the link between production difficulty and grammatical variability. Using a sub-sample of the Switchboard Corpus of American English (285 transcripts, 34 speakers), this paper shows that the presence of variable contexts does not positively correlate with two metrics of production difficulty, namely filled pauses (um and uh) and unfilled pauses (speech planning time). When 20 morphosyntactic variables are considered collectively (N= 6,268), there is no positive effect. In other words, variable contexts do not correlate with measurable production difficulties. These results challenge the view that grammatical variability is somehow sub-optimal for speakers, with additional burdensome cognitive planning.

A Cross-Linguistic Study of Individual Differences in Speech Planning

Although previous research has shown that there exist individual and cross-linguistic differences in planning strategies during language production, little is known about how such individual differences might vary depending on which language a speaker is planning. The present series of studies examines individual differences in planning strategies exhibited by speakers of American English, French, and German. Participants were asked to describe images on a computer monitor while their eye movements were monitored. In addition, we measured participants' working memory capacity and speed of processing. The results indicate that in the present study, English and German were planned less incrementally (further in advance) prior to speech onset compared to French, which was planned more incrementally (not as far in advance). Crucially, speed of processing predicted the scope of planning for French speakers, but not for English or German speakers. These results suggest that the different planning strategies that are invoked by syntactic choices available in different languages are associated with the tendency for speakers to rely on different cognitive support systems as they plan sentences.

Changes in Intermuscular Coherence as a Function of Age and Phase of Speech Production During an Overt Reading Task

Purpose: The authors evaluated changes in intermuscular coherence (IMC) of orofacial and speech breathing muscles across phase of speech production in healthy younger and older adults. Method: Sixty adults (30 younger = M: 26.97 year; 30 older = M: 66.37 year) read aloud a list of 40 words. IMC was evaluated across phase: preparation (300 ms before speech onset), initiation (300 ms after onset), and total execution (entire word). Results: Orofacial IMC was lowest in the initiation, higher in preparation, and highest for the total execution phase. Chest wall IMC was lowest for the preparation and initiation and highest for the total execution phase. Despite age-related differences in accuracy, neuromuscular modulation for phase was similar between groups. Conclusion: These results expand our knowledge of speech motor control by demonstrating that IMC is sensitive to phase of speech planning and production.