Purpose: Real-time magnetic resonance imaging (MRI) and accompanying analytical methods are shown to capture and quantify salient aspects of apraxic speech, substantiating and expanding upon evidence provided by clinical observation and acoustic and kinematic data. Analysis of apraxic speech errors within a dynamic systems framework is provided and the nature of pathomechanisms of apraxic speech discussed. Method: One adult male speaker with apraxia of speech was imaged using real-time MRI while producing spontaneous speech, repeated naming tasks, and self-paced repetition of word pairs designed to elicit speech errors. Articulatory data were analyzed, and speech errors were detected using time series reflecting articulatory activity in regions of interest.Results: Real-time MRI captured two types of apraxic gestural intrusion errors in a word pair repetition task. Gestural intrusion errors in nonrepetitive speech, multiple silent initiation gestures at the onset of speech, and covert (unphonated) articulation of entire monosyllabic words were also captured. Conclusion: Real-time MRI and accompanying analytical methods capture and quantify many features of apraxic speech that have been previously observed using other modalities while offering high spatial resolution. This patient's apraxia of speech affected the ability to select only the appropriate vocal tract gestures for a target utterance, suppressing others, and to coordinate them in time.

Research on geminate consonants has attempted to establish whether the control of their articulation differs from that of corresponding singletons in temporal parameters, spatial parameters, or both. One piece of evidence supporting spatial control in Italian geminates is EPG results revealing that the location of maximal constriction (CL) of coronal geminates along the palate exhibits small differences from the CL of singletons (Payne 2005). However, our recent work investigating Italian using real-time magnetic resonance imaging (MRI) has shown that when measuring CL dynamically, the CL of singletons and geminates are identical. Dynamic CL is defined as the region of the image that exhibits maximum intensity change during constriction formation and release. These results can be reconciled with the EPG findings if we hypothesize that differences in CL at the moment of maximal constriction are due to compression effects (in the longer geminates) involving the tongue tip sliding along the palate during the closure duration. We evaluate this hypothesis by testing whether CL differences between singletons and geminates can also be found in MRI data, when CL is measured statically (region on the palate contacted in the most constricted frame) in the same utterances in which dynamic CL is invariant. [Work supported by NIH.]

We investigate articulatory behavior in post-glossectomy speech using real-time magnetic resonance imaging. Our data reveal that listeners judge speech produced by partial-glossectomy patients as atypical when the surgical procedure affected the oral tongue. Speech produced by patients whose procedure affected the base of tongue, however, was judged as typical. We observe that preservation and compensation mechanisms are exhibited by the patients with atypical speech. They preserve appropriate modulation of F1 using tongue and/or jaw height despite inability to appropriately modulate F2 due to the reduced size and/or mobility of the tongue. Further, durational differences between tense and lax vowels are maintained. The preservation of these features serves as evidence in support of a framework within which individual gestural parameters are independently controlled; when achievement of a particular parameter specification (e.g., constriction location) is compromised, the remaining (e.g., constriction degree, activation duration) are unchanged. Compensatory behavior is exhibited when coronal tongue movement has been impeded and is exemplified by (i) production of labiodental stops in place of target coronal stops and laterals and (ii) forming a velar constriction to produce frication in place of the alveolar frication for /s/.

Purpose Facial transplantation involves partial or total replacement of neuromuscular and skeletal structures of the face, head, and neck using donor tissues and is among the most extensive facial reconstructive procedures. This case report compares changes in speech production and articulator movement in a 44-year-old man from pretransplant to a 13-month posttransplant period. Method Speech production and articulator movement data were examined at 5 time points, once pretransplant and 4 times posttransplant (4, 7, 10, and 13 months), and compared to 4 healthy controls. A motion capture system was used to track jaw and vertical/horizontal lip movement during nonspeech and speech tasks. Speech intelligibility, jaw displacement, lip aperture, and movement variability were measured. Results Speech intelligibility varied across the study period and was restored to control status by 7 months posttransplant. Jaw displacement and lip aperture in the vertical plane significantly increased over time for nonspeech and speech tasks. Changes in horizontal lip movements over time were minimal. Jaw and lip movement variability fluctuated over time and was greater than the controls by 13 months posttransplant. Discussion Findings quantify changes in articulator movement and contributions to improved speech production following facial transplant. Changes reflect the adaptability of the speech motor system and are discussed in relation to pretransplant speech motor control patterns.