The most frequently used method for evaluating tremor in Parkinson’s disease (PD) is currently the internationally standardized Movement Disorder Society—Unified PD Rating Scale (MDS-UPDRS). However, the MDS-UPDRS is associated with limitations, such as its inherent subjectivity and reliance on experienced raters. Objective motor measurements using accelerometry may overcome the shortcomings of visually scored scales. Therefore, the current study focuses on translating the MDS-UPDRS tremor tests into an objective scoring method using 3D accelerometry. An algorithm to measure and classify tremor according to MDS-UPDRS criteria is proposed. For this study, 28 PD patients undergoing neurosurgical treatment and 26 healthy control subjects were included. Both groups underwent MDS-UPDRS tests to rate tremor severity, while accelerometric measurements were performed at the index fingers. All measurements were performed in an off-medication state. Quantitative measures were calculated from the 3D acceleration data, such as tremor amplitude and area-under-the-curve of power in the 4–6 Hz range. Agreement between MDS-UPDRS tremor scores and objective accelerometric scores was investigated. The trends were consistent with the logarithmic relationship between tremor amplitude and MDS-UPDRS score reported in previous studies. The accelerometric scores showed a substantial concordance (>69.6%) with the MDS-UPDRS ratings. However, accelerometric kinetic tremor measures poorly associated with the given MDS-UPDRS scores (R2 < 0.3), mainly due to the noise between 4 and 6 Hz found in the healthy controls. This study shows that MDS-UDPRS tremor tests can be translated to objective accelerometric measurements. However, discrepancies were found between accelerometric kinetic tremor measures and MDS-UDPRS ratings. This technology has the potential to reduce rater dependency of MDS-UPDRS measurements and allow more objective intraoperative monitoring of tremor.

This study introduces a method ideally suited for investigating toddlers’ ability to detect mispronunciations in lexical representations: pupillometry. Previous research has established that the magnitude of pupil dilation reflects differing levels of cognitive effort. Building on those findings, we use pupil dilation to study the level of detail encoded in lexical representations with 30-month-old children whose lexicons allow for a featurally balanced stimulus set. In each trial, we present a picture followed by a corresponding auditory label. By systematically manipulating the number of feature changes in the onset of the label (e.g., baby ∼ daby ∼ faby ∼ shaby), we tested whether featural distance predicts the degree of pupil dilation. Our findings support the existence of a relationship between featural distance and pupil dilation. First, mispronounced words are associated with a larger degree of dilation than correct forms. Second, words that deviate more from the correct form are related to a larger dilation than words that deviate less. This pattern indicates that toddlers are sensitive to the degree of mispronunciation, and as such it corroborates previous work that found word recognition modulated by sub-segmental detail and by the degree of mismatch. Thus, we establish that pupillometry provides a viable alternative to paradigms that require overt behavioral response in increasing our understanding of the development of lexical representations.

Linguistic evidence suggests that syllables like bdam (with stop-stop clusters) are less preferred than bzam (with stop-fricative combinations). Here, we demonstrate that English speakers manifest similar preferences despite no direct experience with either structure. Experiment 1 elicited syllable count for auditory materials (e.g., does bzam have one syllable or two?); Experiment 2 examined the AX discrimination of auditory stimuli (e.g., is bzam = bezam?); whereas Experiment 3 repeated this task using printed materials. Results showed that syllables that are dispreferred across languages (e.g., bdam) were prone to misidentification relative to preferred syllables (e.g., bzam). The emergence of this pattern irrespective of stimulus modality--for auditory and printed materials--suggests that misidentification does not solely stem from a phonetic failure. Further, the effect remained significant after controlling for various statistical properties of the materials. These results suggest that speakers possess broad linguistic preferences that extend to syllables they have never encountered before.