Doris Mücke

Previous studies have demonstrated that focus significantly alters sentential prosody in Persian. However, research on the phonetic realization of non-corrective narrow focus is scarce compared to that on broad and corrective focus. This paper presents a systematic production study investigating whether Persian speakers distinguish between three focus structures on target words that bear a pitch accent, that is, broad, narrow, and corrective focus. In a multidimensional phonetic analysis, we investigated the parameters of intensity, duration, and F0. Taking a local perspective, results show that the duration of the target word is a robust cue for focus marking in both syllables of the word, exhibiting a three-step pattern (corrective > narrow > broad). In the first syllable, intensity is a reliable cue to distinguish broad focus from the other two focus types, with higher intensities in broad focus. In the accented syllable, a different two-step pattern is observed, with narrow and corrective focus showing larger F0 spans than broad focus. Taking a global perspective that considers the parts of the utterance before and after the target word, we find a lowering of F0 and decreased intensity for narrow and corrective focus in the pre-target region. In the post-target region, we find strong evidence for differences in mean F0 and intensity with lower F0 in corrective focus than in broad and narrow focus, while the intensity is lower in narrow and corrective focus than in broad focus. Our analysis deepens our understanding of Persian prosody.

Speakers modify their supra-laryngeal articulation on the one hand as a function of prosodic prominence and on the other hand as a function of speaking style. Articulatory movements are spatio-temporally expanded in words that are highlighted due to prosodic strengthening, but also in utterances that are produced in a loud speaking style. What remains unclear, to date, is how these two phenomena interact, or, in other words, how prominence relations are encoded in loud speech. In this paper, we use electromagnetic articulography to investigate lip and tongue kinematics and analyze selected acoustic parameters across several focus conditions in habitual and loud speech. Prosodic prominence relations are studied as the simultaneous strengthening of highlighted words and the attenuation of words in the background. The results show that prominence relations can be encoded multidimensionally in loud speech. Some modifications are even stronger in loud speech than in habitual speech, despite the general articulatory modifications associated with a loud speaking style. In both speaking styles, the attenuation of words in the background tends to be more robust than the strengthening of highlighted words. The paper underlines the flexibility of the multidimensional phonetic space in the encoding of prosodic prominence across varying communicative demands.

Objective: This study aims to shed light on structural networks associated with stimulation-induced dysarthria (SID) and to derive a data-driven model to predict SID in patients with Parkinson’s Disease (PD) and deep brain stimulation (DBS) of the subthalamic nucleus (STN). Methods: Randomized, double-blinded monopolar reviews determining SID thresholds were conducted in 25 patients with PD and STN-DBS. A fiber-based mapping approach, based on the calculation of fiber-wise Odds Ratios for SID, was employed to identify the distributional pattern of SID in the STN’s vicinity. The ability of the data-driven model to classify stimulation volumes as “causing SID” or “not causing SID” was validated by calculating receiver operating characteristics (ROC) in an independent out-of-sample cohort comprising 14 patients with PD and STN-DBS. Results: Local fiber-based stimulation maps showed an involvement of fibers running lateral and postero-medial to the STN in the pathogenesis of SID, independent of the investigated hemisphere. ROC-analysis in the independent out-of-sample cohort resulted in a good fit of the data-driven model for both hemispheres (AUC _left = 0.88, AUC _right = 0.88). Interpretation: This study reveals an involvement of both, cerebello-thalamic fibers, as well as the pyramidal tract, in the pathogenesis of SID in STN-DBS. The results may impact future postoperative programming strategies to avoid SID in patients with PD and STN-DBS.

This study aims to explore the effects of healthy aging and Parkinson’s disease on speech motor performance. One area of speech production which requires fine speech motor control is prominence marking. Therefore, strategies of prominence marking of three speaker groups with four speakers each were investigated: younger speakers, older speakers, and speakers with Parkinson’s disease (PD). Acoustic and articulatory data were collected. Speech data were analyzed focusing on prominence-related adjustments of vowel production and tongue body movements in the temporal and spatial domain. Longer durations, varying initiation of the tongue movements and smaller vowel sizes in older speakers and in speakers with PD were found compared to younger speakers. The data indicate further that all speaker groups mark prominence by changing relevant parameters in the vowel articulation; however, strategies seem to differ between the groups: (i) in the temporal domain, articulatory movement durations increase with age and are further prolonged in speakers with PD; (ii) in the spatial domain, the articulation space is resized by the older speakers in a non-symmetrical way, while no systematic vocalic modulations were found for speakers with PD. To conclude, the speech system seems to be affected by age and disease, but speakers develop compensatory strategies to counteract influences in the spatial domain.

The present study investigates speech changes in Parkinson’s disease on the acoustic and articulatory level with respect to prosodic prominence marking. To display movements of the underlying articulators, speech data from 16 patients with Parkinson’s disease were recorded using electromagnetic articulography. Speech tasks focused on strategies of prominence marking. Patients’ ability to encode prominence in the laryngeal and supra-laryngeal domain is tested in two conditions to examine the influence of motor performance on speech production further: without dopaminergic medication and with dopaminergic medication. The data reveal that patients with Parkinson’s disease are able to highlight important information in both conditions. They maintain prominence relations across- and within-accentuation by adjusting prosodic markers, such as vowel duration and pitch modulation, while the acoustic vowel space remains the same. For differentiating across-accentuation, not only intensity but also all temporal and spatial parameters related to the articulatory tongue body movements during the production of vowels are modulated to signal prominence. In response to the levodopa intake, gross motor performance improved significantly by 42%. The improvement in gross motor performance was accompanied by an improvement in speech motor performance in terms of louder speech and shorter, larger and faster tongue body movements. The tongue body is more agile under levodopa increase, a fact that is not necessarily detectable on the acoustic level but important for speech therapy.

Objective: To gain insights into structural networks associated with stimulation-induced dysarthria (SID) and to predict stimulation-induced worsening of intelligibility in essential tremor patients with bilateral thalamic deep brain stimulation (DBS). Methods: Monopolar reviews were conducted in 14 essential tremor patients. Testing included determination of SID thresholds, intelligibility ratings and a fast syllable repetition task. Volumes of tissue activated (VTAs) were calculated to identify discriminative fibers for stimulation-induced worsening of intelligibility in a structural connectome. The resulting fiber-based atlas structure was than validated in a leave-one-out design. Results: Fibers determined as discriminative for stimulation-induced worsening of intelligibility were mainly connected to the ipsilateral precentral gyrus as well as to both cerebellar hemispheres and the ipsilateral brainstem. In the thalamic area, they ran laterally to the thalamus and postero-medially to the subthalamic nucleus, in close proximity, mainly antero-laterally, to fibers beneficial for tremor control as published by Al-Fatly et al. (2019). The overlap of the respective clinical stimulation setting’s VTAs with these fibers explained 62.4% (p<0.001) of the variance of stimulation-induced change in intelligibility in a leave-one out analysis. Interpretation: This study demonstrates that SID in essential tremor patients is associated with both, motor cortex and cerebellar connectivity. Furthermore, the identified fiber-based atlas structure might contribute to future postoperative programming strategies to achieve optimal tremor control without speech impairment in ET patients with thalamic DBS.

To assess a phonological theory, we often compare its predictions to phonetic observations. This can be complicated, however, because it requires a theoretical model that maps from phonological representations to articulatory and acoustic observations. In this study we are concerned with the question of how phonetic observations are interpreted in relation to phonological theories. Specifically, we argue that deviations of observations from theoretical predictions do not necessitate the rejection of the theoretical assumptions. We critically discuss the problem of overinterpretation of phonetic measures by using syllable coordination for different speaker groups within Articulatory Phonology. It is shown that surface variation can be explained without necessitating substantial revision of the underlying phonological theory. These results are discussed with respect to two types of interpretational errors in the literature. The first involves the proliferation of phonological categories in order to accommodate variation, and the second the rejection of a phonological theory because the model which generates its predictions is overly simplified.