Just Noticeable Difference Research Articles

Using machine learning to predict internal rotation after anatomic and reverse total shoulder arthroplasty.

Improvement in internal rotation (IR) after anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty is difficult to predict, with rTSA patients experiencing greater variability and more limited IR improvements than aTSA patients. The purpose of this study is to quantify and compare the IR score for aTSA and rTSA patients and create supervised machine learning that predicts IR after aTSA and rTSA at multiple postoperative time points. Clinical data from 2270 aTSA and 4198 rTSA patients were analyzed using 3 supervised machine learning techniques to create predictive models for internal rotation as measured by the IR score at 6 postoperative time points. Predictions were performed using the full input feature set and 2 minimal input feature sets. The mean absolute error (MAE) quantified the difference between actual and predicted IR scores for each model at each time point. The predictive accuracy of the XGBoost algorithm was also quantified by its ability to distinguish which patients would achieve clinical improvement greater than the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) patient satisfaction thresholds for IR score at 2-3 years after surgery. rTSA patients had significantly lower mean IR scores and significantly less mean IR score improvement than aTSA patients at each postoperative time point. Both aTSA and rTSA patients experienced significant improvements in their ability to perform activities of daily living (ADLs); however, aTSA patients were significantly more likely to perform these ADLs. Using a minimal feature set of preoperative inputs, our machine learning algorithms had equivalent accuracy when predicting IR score for both aTSA (0.92-1.18 MAE) and rTSA (1.03-1.25 MAE) from 3 months to >5 years after surgery. Furthermore, these predictive algorithms identified with 90% accuracy for aTSA and 85% accuracy for rTSA which patients will achieve MCID IR score improvement and predicted with 85% accuracy for aTSA patients and 77% accuracy for rTSA which patients will achieve SCB IR score improvement at 2-3 years after surgery. Our machine learning study demonstrates that active internal rotation can be accurately predicted after aTSA and rTSA at multiple postoperative time points using a minimal feature set of preoperative inputs. These predictive algorithms accurately identified which patients will, and will not, achieve clinical improvement in IR score that exceeds the MCID and SCB patient satisfaction thresholds.

Differential Etv2 threshold requirement for endothelial and erythropoietic development.

SUMMARYEndothelial and erythropoietic lineages arise from a common developmental progenitor. Etv2 is a master transcriptional regulator required for the development of both lineages. However, the mechanisms through which Etv2 initiates the gene-regulatory networks (GRNs) for endothelial and erythropoietic specification and how the two GRNs diverge downstream of Etv2 remain incompletely understood. Here, by analyzing a hypomorphic Etv2 mutant, we demonstrate different threshold requirements for initiation of the downstream GRNs for endothelial and erythropoietic development. We show that Etv2 functions directly in a coherent feedforward transcriptional network for vascular endothelial development, and a low level of Etv2 expression is sufficient to induce and sustain the endothelial GRN. In contrast, Etv2 induces the erythropoietic GRN indirectly via activation of Tal1, which requires a significantly higher threshold of Etv2 to initiate and sustain erythropoietic development. These results provide important mechanistic insight into the divergence of the endothelial and erythropoietic lineages.

Is There a Time-Sensitive Window in Patients With Stroke to Enhance Arm Recovery With Higher Intensity Motor Therapy?

Is There a Time-Sensitive Window in Patients With Stroke to Enhance Arm Recovery With Higher Intensity Motor Therapy?

Minimal important difference and patient acceptable symptom state for the Numerical Rating Scale (NRS) for pain and the Patient-Rated Wrist/Hand Evaluation (PRWHE) for patients with osteoarthritis at the base of thumb

BackgroundThe Numerical Rating Scale (NRS) and Patient-rated wrist/hand evaluation (PRWHE) are patient-reported outcomes frequently used for evaluating pain and function of the wrist and hand. The aim of this study was to determine thresholds for minimal important difference (MID) and patient acceptable symptom state (PASS) for NRS pain and PRWHE instruments in patients with base of thumb osteoarthritis.MethodsFifty-two patients with symptomatic base of thumb osteoarthritis wore a splint for six weeks before undergoing trapeziectomy. NRS pain (0 to 10) and PRWHE (0 to 100) were collected at the time of recruitment (baseline), after splint immobilization prior to surgery, and at 3, 6, 9 and 12 months after surgery. Four anchor-based methods were used to determine MID for NRS pain and PRWHE: the receiver operating characteristics (ROC) curve, the mean difference of change (MDC), the mean change (MC) and the predictive modelling methods. Two approaches were used to determine PASS for NRS pain and PRWHE: the 75th percentile and the ROC curve methods. The anchor question for MID was the change perceived by the patient compared with baseline; the anchor question for PASS was whether the patient would be satisfied if the condition were to stay similar. The correlation between the transition anchor at baseline and the outcome at all time points combined was calculated using the Spearman’s rho analysis.ResultsThe MID for NRS pain was 2.5 using the ROC curve method, 2.0 using the MDC method, 2.8 using the MC method, and 2.5 using the predictive modelling method. The corresponding MIDs for PRWHE were 22, 24, 10, and 20. The PASS values for NRS pain and PRWHE were 2.5 and 30 using the ROC curve method, and 2.0 and 22 using the 75th percentile method, respectively. The area under curve (AUC) analyses showed excellent discrimination for all measures.ConclusionWe found credible MID estimates for NRS and PRWHE (including its subscales), although the MID estimates varied depending on the method used. The estimates were 20-30% of the range of scores of the instruments. The cut-offs for MID and PASS showed good or excellent discrimination, lending support for their use in future studies.Trial registrationThis clinimetrics study was approved by the Helsinki University ethical review board (HUS1525/2017).

Observational Study on the Variability of Mixed Layer Depth in the Bering Sea and the Chukchi Sea in the Summer of 2019

Based on the CTD data from 58 stations in the Bering Sea and the Chukchi Sea in the summer of 2019, the values of mixed layer depth (MLD) were obtained by using the density difference threshold method. It was concluded that the MLD can be estimated more accurately by using a criterion of 0.125 kg/m3 in this region. The average MLD in the Bering Sea basin was larger than that in the Bering Sea shelf, and both of them were smaller than that in the Bering Sea slope. The MLD increased northward in both the Chukchi Sea shelf and the Chukchi Sea slope. The farther northward, the greater the difference between the MLD calculated from temperature (MLDt) and the MLD calculated from density (MLDd). The water masses and their interaction played an important role in the variation of MLD in the northern Bering Sea shelf and Chukchi Sea. The MLD was large due to the vertically homogeneous Anadyr Water in the northwestern Bering Sea shelf. The horizontal advection of Bering Sea Anadyr Water and Alaska Coastal Water in the Bering Sea shelf led to shallower MLD in the central northern Bering Sea shelf. The westward advection of the Alaska Coastal Water caused shallow mixed layers (MLs) in some regions of the Chukchi Sea shelf in the summer of 2019. The observed large MLD at BL01 station near the Aleutian Island was caused by an anticyclonic eddy. The northward increase in the MLD in the Chukchi Sea was related to the low-salinity seawater from sea ice melting in summer. The spatial variation of MLD was also closely related to the surface momentum flux and the sea surface buoyancy flux. Stratification plays an even more important role in determining the variation of MLD. The ML in 2019 was shallower and warmer than those in previous years, especially in the Bering Sea shelf and Chukchi Sea where sea ice volume, thickness, and coverage were significantly larger than the Bering Sea basin, which was related to the small sea ice volume in winter and spring of 2019 compared to previous years.

The enhancement of the perception of saltiness by umami sensation elicited by flavor enhancers in salt solutions

Health concerns related to the intake of salt have encouraged the investigation into sodium reduction by examining the taste-taste interaction between the perception of saltiness and umami. The effect of saltiness enhancement and sodium reduction of four kinds of umami carrier (WSA, MSG, IMP, and I + G) in a salt model solution with different salt concentrations (2.03–13.94 g/L) were investigated using the two-alternative forced-choice (2-AFC) and generalized Labeled Magnitude Scale (gLMS). The saltiness difference thresholds (DT) under different umami carrier were further explored using the constant stimuli method. The results showed that umami carriers had effective effects of saliness enhancement in the salt solutions with different concentrations, and higher enhancemen levels were obtained at larger salt concentrations. The level of saltiness enhancement were varied between the different umami intensity and carriers, and WSA carrier with moderate intensity had the maximum sodium reduction percentages which reached to 24.25%. Besides, the DT values of saltiness taste were increased under umami carrier, which means that more salt can be reduced without evoking a variation in saltiness. The present work not only provided insight into the effect of umami chemicals on the saltiness perception and saltiness DT values but also presented valuable information regarding flavor when developing low sodium foods and contributing to the development of more healthful products that meet current nutritional recommendations.

InSpace Implant Compared with Partial Repair for the Treatment of Full-Thickness Massive Rotator Cuff Tears: A Multicenter, Single-Blinded, Randomized Controlled Trial.

The purpose of this study was to prospectively evaluate the efficacy and safety of a subacromial balloon spacer (InSpace implant; Stryker) compared with arthroscopic partial repair in patients with irreparable, posterosuperior massive rotator cuff tears. Patients ≥40 years of age with symptomatic, irreparable, posterosuperior, massive rotator cuff tears and an intact subscapularis who underwent failed nonoperative management were included in this randomized controlled trial comparing the InSpace implant with partial repair. Clinical outcome data were collected at baseline through a 24-month follow-up. The primary outcome was improvement in the American Shoulder and Elbow Surgeons (ASES) scores. The secondary outcomes included change from baseline in the Western Ontario Rotator Cuff (WORC) score, the visual analog scale (VAS) pain score, the Constant-Murley shoulder score, the EuroQol-5 Dimensions-5-Level (EQ-5D-5L) score, active range of motion, and operative time. Complications and reoperations for each group were also recorded. Twenty sites randomized 184 patients: 93 in the InSpace group and 91 in the partial repair group. Significant and clinically relevant improvements in the ASES score from baseline were noted in both groups at Month 12 and were maintained at Month 24. Overall, 83% of patients in the InSpace group and 81% of patients in the partial repair group achieved the ASES minimally clinically important difference threshold, and 82% of patients in the InSpace group and 79% of patients in the partial repair group achieved the substantial clinical benefit threshold. Forward elevation was significantly greater in the InSpace group compared with the partial repair group at Day 10 (p = 0.04), Week 6 (p = 0.0001), Month 12 (p = 0.005), and Month 24 (p = 0.003). The operative time was significantly shorter in the InSpace group (p < 0.0001). No device-related surgical complications were noted, and 4 reoperations after InSpace implantation and 3 reoperations after partial repair were required. The InSpace implant is an appropriate alternative to partial repair in patients with irreparable posterosuperior massive rotator cuff tears and an intact subscapularis. Notable benefits include early functional recovery and pain relief combined with a shorter operative time. Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Clinical relevance of increased antibody titres in older adults upon vaccination with squalene-adjuvanted versus non-adjuvanted influenza vaccines

In older adults, the serum antibody response to inactivated influenza vaccine (IIV) is often lower than in adolescents and non-elderly adults which may translate into suboptimal protection against influenza. To counteract this expression of immunosenescence, the use of adjuvanted IIV formulations has been explored. Four recent studies (three meta-analyses and one clinical trial) found an antibody increase of up to 1.5-fold in older adults, when a squalene-adjuvanted (MF59™) IIV was used. The clinical relevance of this increase may well continue to be a matter of debate. We would favour a threshold of 1.5 to consider an adjuvanted vaccine formulation superior to standard aqueous IIV because it exceeds the inevitable variation of antibody responses to non-adjuvanted IIV. It is also the same as the upper FDA equivalence limit for IIV lot-to-lot consistency. A corresponding threshold for the seroresponse rate difference could then be +5%.

Recognition Method of Wushu Human Complex Movement Based on Bone Point Feature

The existing recognition methods of complex human movements in Wushu have the problem of imperfect kinetic energy model, which leads to low recognition accuracy. A complex human motion recognition method based on bone point features is designed. Identify martial arts movement posture, combine the upward movement of human center of gravity trajectory, establish the kinetic energy model of joints according to the positioning results of extremity points, set the threshold of local spatial differences of human bones with the central node of hip joint as the center point, avoid overcalculation, and optimize the complex motion identification process by combining the characteristics of bone points. Experimental Results. The correct rate of different types of actions identified by this method is 90.1% and 92.7%, and the identification time is 1.2 s and 1.41 s, which shows that this method can identify actions quickly and effectively by combining the feature information of bone points.

The effect of the heat transfer mechanism on the psychophysical assessment of moisture sensation in fabrics

Perceived moisture in fabrics is a crucial factor affecting wearing comfort. The aim of the current study was to investigate the effect of the conductive, evaporative and mechanical cues on moisture sensation. Thirteen participants assessed fabric wetness perception in both hot and neutral environments, and the difference threshold and the sensory magnitude of moisture were determined. Three types of knitted fabric were covered with or without an impermeable polyvinyl chloride (PVC) film and were used to simulate either the water evaporation or not. The results showed that the influence of conduction on moisture sensitivity was greater than that of evaporation, as proved by the 0.1 units of increase in the Webber fraction by conduction, compared with only 0.03 units of increase by evaporation. In addition, the relationship between the moisture sensation and the stimulus intensity demonstrated a psychophysical power function. The exponents of the power functions were found to be between 0.15 and 0.45, depending on the stimulus conditions, and the cold-wet stimulus triggered significantly greater moisture sensation than the warm-wet stimulus. Fabrics restrained from evaporation by PVC film resulted in a greater moisture sensation as the supplied water was held as free liquid, which either increased cooling cues in the cold-wet stimulus or increased mechanical cues in the warm-wet stimulus. The results suggest that factors such as clothing fitness, fabric property and environmental conditions might interactively affect human moisture sensation, and future researches are necessary to understand how these initial results would relate to an overall garment.

Forward-reverse fractional and fuzzy logic augmented partial differential equation-based enhancement and thresholding for degraded document images

This paper presents a thresholding algorithm using an alternate forward-reverse flow-based partial differential equation (PDE)-based formulation. Additionally, revised models are augmented with fuzzy intensification and fuzzy rule-based structure tensor edge terms for handling degraded document images. Furthermore, an effective technique for enhancement of document images with extreme bleed-through is proposed to further improve binarization results. Comparisons with state-of-the-art PDE thresholding/binarization approaches show superior results of proposed methods based on visual and objective analysis.

Human auditory frequency discrimination and inter-stimulus interval

The goal of this study was to determine how human performance in discriminating between similar frequencies in the auditory spectrum was influenced by modifying the interstimulus interval (ISI). The ISI is defined as the time elapsed from the end of the first stimulus and the beginning of the second stimulus. The relationship between ISI and auditory discrimination was explored using an auditory file comprised of 40 tests that each contained two tones with a frequency difference of 1%. For each test, 44 participants were asked to select the tone they perceived as being a higher frequency. The two frequencies used in each test were centered around one of five base frequencies, and the ISI used in each test was one of eight predetermined intervals. Results from previous auditory frequency discrimination studies regarding the just-noticeable difference (JND) and Weber’s law were used in the selection of the frequency difference of 1% that was used in this experiment. This frequency difference was kept constant across all the tests in order to ensure that the ISI was the main factor influencing participant performance. Participant performance was greatest at an ISI of 1000 ms when results were averaged by frequency. Additionally, as the base frequency increased, average performance generally improved. The findings from this experiment promote further investigation into the effects of varying ISI on the integration of auditory information by the auditory cortex.

Patient-reported health-related quality of life from a randomized, placebo-controlled phase 2 trial of zuranolone in adults with major depressive disorder

BackgroundMajor depressive disorder (MDD), a disabling, potentially life-threatening condition, negatively affects health-related quality of life (HRQoL). This secondary analysis aimed to understand the impact of the neuroactive steroid zuranolone on HRQoL using the Short Form-36v2 Health Survey (SF-36v2). MethodsAdult patients with MDD and 17-item Hamilton Rating Scale for Depression total score ≥22 were randomized 1:1 to receive zuranolone 30 mg or placebo for 2 weeks, with 4 weeks follow-up. SF-36v2 scores were assessed at Day 15 across 8 domains (Physical Functioning, Role Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role Emotional, and Mental Health) and 2 summary scores (Physical and Mental Component), using a mixed-effects model for repeated measures. Correlations between SF-36v2 scores and clinician-reported efficacy endpoints were assessed using Pearson's correlation. ResultsEighty-nine patients were treated with zuranolone 30 mg (n = 45) or placebo (n = 44). In zuranolone-treated patients, HRQoL improved across all SF-36v2 domains and summary scores at Day 15. Improvements exceeding established minimally important difference thresholds were observed in Bodily Pain, General Health, Vitality, Social Functioning, Role Emotional, and Mental Health scores. Improvements in General Health, Vitality, Mental Health, and Mental Component Summary were statistically significant versus placebo (p ≤ 0.025). Clinician-rated endpoints negatively correlated with SF-36v2 scores. LimitationsThe small unipolar depression sample may not be representative of all US MDD patients. HRQoL measures could be impacted by factors unrelated to depression. ConclusionsZuranolone-treated patients reported rapid and significant improvements in HRQoL versus placebo at Day 15. HRQoL improvements correlated with improvements in clinician-rated assessments.Trial registration:clinicaltrials.gov:NCT03000530; https://clinicaltrials.gov/ct2/show/NCT03000530.

Pitch-timbre interactions as measured in discrimination and the frequency-following response

Perceptual interactions between pitch and timbre have been demonstrated repeatedly using discrimination tasks in psychoacoustics. The current study investigates whether the pitch-timbre interaction is reflected in neural signatures of pitch encoding in the brainstem. Listeners discriminated the pitch of harmonic tone complexes with low- or high-spectral centroids (SC) in a yes/no task. Fundamental frequency (F0) varied by one just noticeable difference (JND), while SC could be varied by two- or five- JNDs. Discrimination performance increased when both F0 and SC were higher as opposed to when one was higher, and one was lower. This suggests that higher SCs bias listeners toward “higher pitch” responses, replicating previous studies. Frequency-following responses (FFR) were obtained in response to the same stimuli from the same listeners. The recorded FFR signals were analyzed using autocorrelation functions, to evaluate the coding of periodicity, and the Fourier spectra, as an indicator of the encoded F0. The encoding of pitch-relevant information was similar for all stimuli, regardless of SC. Contrary to bias observed in pitch discrimination performance imposed by SC, the lack of a significant influence of SC in the FFR measurements suggests that the pitch-timbre interaction was not observed at the level of the brainstem.

Explore Electrotactile Parametric Properties Using an Electrical Stimulation System

Influenced by multiple factors, to understand electrotactile properties is challenging but significant in comparing individual differences, parameters control and coding, and model studies. However, the inadequacy of measurement systems and methods limits the application and development of electrotactile feedback. This study focuses on the exploration of parametric properties using an electrical stimulation system (ESS) via innovative measurement methods and electrotactile control. A 6-channel portable stimulator and a graphical user interface (GUI) with interactive algorithms have been designed. Modified staircase method, bisection and parametric-random algorithms are developed for the psychophysical measurement of detection thresholds (DT), pain threshold (PT), just-noticeable difference (JND), parameter-intensity properties (PIP) and sensitivity index (SI). The system performance is verified by conducting four sub-experiments on eight subjects. Bisection algorithm is proved to be more robust (p < 0.05). JND measurement based on bisection algorithm achieves 50% efficiency improvement over traditional methods. The individual differences and sensitivities are quantified by SI. The JND and PIP measurement results indicate the potential for iso-resolution and iso-intensity control in information coding as well as parameter-intensity modelling. The results of this paper could provide a basis for tactile information encoding as well as an experimental platform for investigating perception mechanism.

The effects of phonological content, sentence context, and vocoding on voice cue perception

Recently, we showed the effect of lexical content on just-noticeable-differences (JNDs) in voice pitch (F0) and vocal-tract length (VTL) voice cue perception. Participants performed an adaptive 3AFC task with non-vocoded and vocoded auditory stimuli. When presented with words, participants showed smaller VTL JNDs compared to time-reversed words, also when vocoding was applied. These outcomes inspired two follow-up studies using similar methods. The first study compared words, time-reversed words, and non-words, to investigate if the benefit is related more specifically to lexical (words) and/or phonological (non-words) content. Irrespective of vocoding, reversed words had a detrimental effect on VTL perception, replicating earlier findings. However, VTL JNDs with non-words did not significantly differ from those with words, suggesting linguistic content benefits for VTL perception at a phonological level. The second study compared JNDs with words and sentences and showed, again regardless of vocoding, a benefit in processing a full sentence compared to a single word in both F0 and VTL perception, suggesting that the amount of acoustic speech information and/or semantic context led to increased voice cue sensitivity. These results improve our understanding of the interactive speech and voice perception processes, inspiring rehabilitation tools for CI users with limited access to voice information.

The perception of synthetic speech versus natural speech stimuli in adult listeners

The majority of speech perception research investigates interpersonal perception through presentation of two types of stimuli: synthetic speech and/or natural speech. Synthetically created speech stimuli allows for precisely controlled manipulation of individual acoustic variables, but can sound unnatural calling into questions its ecological validity. Alternatively, natural speech preserves the full complement of redundant acoustic cues yet limits control of specific acoustic parameters. In this study, we investigate speech discrimination comparing perception of specified acoustic parameters (formant transition duration, F3 onset frequency, F3-F2 distance) across three types of speech stimuli: synthetic speech stimuli, natural speech of a standard adult speaker, and each participant’s own voice. We use the Wide Range Acoustic Accuracy Scale (WRAAS), a computer-based perceptual assessment that uses a parameter estimation by sequential testing (PEST) adaptive-tracking algorithm to rapidly identify a listener’s ability to discriminate sounds. Most trials are presented near the Just-Noticeable-Difference (JND) of a stimulus continuum; thus, few trials are “wasted” with obviously same or different sounds. This study of typical adult listeners (n = 20, enrollment is ongoing) will provide baseline data for future work investigating perception of these same stimuli in children.

Effects of word context on formant discrimination

Studies of phonetic variation identify systematic, but often very small, acoustic differences in the realization of vowels. However, it is not known whether such differences are perceptually relevant in realistic contexts. We examine perceptibility of incrementally manipulated differences in F1 and F2 in vowels embedded in real words of English (experiment 1), and vowels in isolation (experiment 2), via an AX discrimination task. Forty listeners in each experiment, recruited through Amazon Mechanical Turk, heard 27 monosyllabic words or vowels in pairs containing a no-change token and a token edited to differ up to ±100 Hz in F1 or ±150 Hz in F2 relative to the original and were asked to say whether tokens were same or different. Discrimination increased with bigger vowel differences (both F1 and F2) in both experiments; however, even maximally different tokens were correctly discriminated less than half the time. F2 discrimination was better in isolated vowels (48%) than in whole words (33%). Compared to previous results in optimized difference limen studies (e.g., Kewley-Port and Watson, 1994), our results show that untrained listeners in more typical listening conditions (non-synthetic speech heard in non-laboratory conditions in real word contexts) require much bigger differences to be perceptible.

Reverse shoulder arthroplasty after failed tendon transfer for irreparable posterosuperior rotator cuff tears.

Tendon transfers (TTs) can be successful for the management of selected posterosuperior functionally irreparable rotator cuff tears. However, when these procedures fail to provide adequate pain relief or functional improvement, reverse shoulder arthroplasty (RSA) is commonly considered the next treatment option. The effect of prior TT on RSA remains largely unknown. The purposes of this investigation were to evaluate the outcomes of RSA after previous TT performed for posterosuperior functionally irreparable rotator cuff tears and to determine the effect of various TT types on RSA. A retrospective review of 2 institutional databases identified 33 patients who underwent RSA implantation between 2006 and 2019 with a previous failed tendon transfer (FTT) of the shoulder and at least 2 years of clinical follow-up. FTTs included 21 latissimus dorsi transfers, 6 latissimus dorsi and teres major (LD-TM) transfers, and 6 lower trapezius transfers. RSAs were performed at an average of 5.5 years (range, 0.3-28 years) after FTT, with a mean follow-up period of 4.1 ± 2.0 years. Outcomes evaluated included the visual analog scale pain score, range of motion, absolute Constant-Murley score (CS) and relative CS, American Shoulder and Elbow Surgeons score, Subjective Shoulder Value, complications, and implant survivorship free of reoperation or revision. RSA significantly improved pain and function, with improvements in the visual analog scale pain score (6.2 preoperatively vs. 2.2 at most recent follow-up, P < .001), active elevation (85° vs. 111°, P < .001), American Shoulder and Elbow Surgeons score (51 vs. 74, P = .001), absolute CS (34 vs. 48, P = .003), and relative CS (42% vs. 59%, P = .002), exceeding the minimal clinically important difference threshold. There were 7 complications (21%) across the entire cohort, with dislocation (n = 3, 9.1%) as the most common complication. Comparison across TT groups showed that LD-TM transfer had the highest complication rate (3 shoulders, 50%), followed by lower trapezius transfer (1 shoulder, 16.7%); latissimus dorsi transfer had the lowest rate (3 shoulders, 14.3%; P = .037). Survivorship free of revision or reoperation was estimated to be 90.1% at 1 year, 84.9% at 2 years, and 71.2% at 5 years, with no difference among TT groups (P = .654). RSA can serve as a viable salvage option for FTT procedures. At mid-term follow-up, RSA led to significant improvements in pain, range of motion, and patient-reported outcomes. Patients with prior LD-TM transfers may have a higher complication rate, but no other differences were found between TT groups.

Perception and timing of acoustic distance

The notion of acoustic distance figures into many aspects of phonetics, including phonological neighborhoods. A measurement of word-level acoustic distance useful for cognitive modeling must account for two listener characteristics: sensitivity to acoustic differences and sensitivity to duration discrepancies between words. The present work used dynamic time warping to measure how acoustic distance accumulates between words over time. The results of a distance rating task with synthesized vowels were used as a basis for selecting a mathematical function that best matched listener sensitivities. Additionally, the results of a reminder task with synthesized vowels were used to determine a just noticeable difference threshold for vowel duration. The results suggested that a distance function based on the 4.5-norm using a 30 ms radius for dynamic time warping best matched human behavior. A third analysis used these dynamic time warping configurations to model reaction times in an auditory lexical decision task and found that Euclidean distance and no temporal constraints on dynamic time warping best matched human behavior. These results are discussed in relation to spoken word recognition models, including how to assess the acoustic match between the speech signal and a word in the lexicon.