Speech is usually produced in an upright sitting or standing posture. Measurements and judgments of speech may be made in conditions requiring a supine position, however. These conditions include MRI recordings, and oral procedures, such as, adjustments to dental appliances, medical and surgical procedures. It is of interest, therefore, to see whether gravity has strong or systematic effects on tongue behavior. In the present study, 13 subjects repeated several words, which contained extreme consonant and vowel tongue positions, during upright and supine condition. Ultrasound imaging provided midsagittal tongue contours, in each condition, for comparison. A neck brace was used to stabilize transducer placement and the palate was used as a physiological reference to register the data sets. Results showed a significant subject effect. In supine position the tongue was more posterior than upright for seven subjects, more anterior for two subjects and varied by phoneme for four subjects. However, there was no significant phoneme effect. The direction of change and the amount of change were not directly related. Most subjects had small upright-supine differences. The largest differences, less than 3 mm on average, were in the posterior tongue.
The tongue is a deformable object, and moves by compressing or expanding local functional segments. For any single phoneme, these functional tongue segments may move in similar or opposite directions, and may reach target maximum synchronously or not. This paper will discuss the independence of five proposed segments in the production of speech. Three studies used ultrasound and tagged Cine-MRI to explore the independence of the tongue segments. High correlations between tongue segments would suggest passive biomechanical constraints and low correlations would suggest active independent control. Both physiological and higher level linguistic constraints were seen in the correlation patterns. Physiological constraints were supported by high correlations between adjacent segments (positive) and distant segments (negative). Linguistic constraints were supported by segmental correlations that changed with the phonemic content of the task.
Citalopram is a member of the selective serotonin reuptake inhibitor class of antidepressants. In 1998, citalopram was approved by the US Food and Drug Administration for the treatment of major depression. Like the other selective serotonin reuptake inhibitors, citalopram enjoys a relatively benign side effect profile compared with the tricyclic antidepressants and the monoamine oxidase inhibitors. However, citalopram has been associated with electrocardiographic changes and seizures at doses greater than 600 mg per day. Fatalities have occurred with citalopram-only overdoses. We report the case of a healthy 21-year-old woman who developed QTc interval prolongation after ingestion of approximately 400 mg citalopram. We discuss the cardiac effects of citalopram, review previous cases of citalopram overdose, and discuss treatment recommendations.
This letter presents a method for imaging the palate and extracting the palate contour from ultrasound images. Ultrasound does not usually capture the palate because the air at the tongue surface reflects the ultrasound beam back to the transducer. However, when the tongue touches the palate during a swallow, the ultrasound beam is transmitted through the soft tissue until it reaches and is reflected by the palate. In combination with tongue contours, the palate contour has the potential for disambiguation of the tongue surface, registration of images within and across subjects, and calculation of phonetically important measures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.