Multidisciplinary Delphi Panel on Rehabilitation Approaches and Unmet Needs for Chronic Stroke Walking Impairment and the Role of Rhythmic Auditory Stimulation.

INTRODUCTION: Walking or gait impairment is a common consequence of stroke that persists into the chronic phase of recovery for many stroke survivors. The goals of this work were to obtain consensus from a multidisciplinary panel on current practice patterns and treatment options for walking impairment after stroke, to better understand the unmet needs for rehabilitation in the chronic phase of recovery and to explore opportunities to address them, and to discuss the potential role of rhythmic auditory stimulation (RAS) in gait rehabilitation. METHODS: A panel of eight experts specializing in neurology, physical therapy, and physiatry participated in this three-part, modified Delphi study. Survey 1 focused on gathering information to develop statements that were discussed and polled during Survey 2 (interactive session), after which revised and new statements were polled in Survey 3. Consensus was defined as ≥75% (6/8 of panelists) agreement or disagreement with a statement. RESULTS: Consensus agreement was ultimately reached on all 24 statements created and polled during this process. The panelists agreed that individuals with gait or walking impairment in the chronic phase of stroke recovery can achieve meaningful improvement in walking by utilizing various evidence-based interventions. Barriers to treatment included cost, access, participation in long-term treatment, and safety. Consensus was achieved for interventions that have the following features challenging, personalized, accessible, and engaging. Improvement of gait speed and quality, durability of effect, safety, affordability, and ability for home or community use also emerged as important treatment features. In addition to conventional treatments (e.g., physical therapy, including mobility-task training and walking/exercise therapy), RAS was recognized as a potentially valuable treatment modality.  Discussion: This panel highlighted limitations of current treatments and opportunities to improve access, participation, and outcomes through a consideration of newer treatment strategies and patient/healthcare provider education and engagement.

One-year budget impact of InTandem™: a novel neurorehabilitation system for individuals with chronic stroke walking impairment.

Aim: Chronic stroke walking impairment is associated with high healthcare resource utilization (HCRU) costs. InTandem™ is a neurorehabilitation system that autonomously delivers a rhythmic auditory stimulation (RAS)-based intervention for the at-home rehabilitation of walking impairment in adults in the chronic phase of stroke recovery. This study was conducted to estimate the budget impact of InTandem in comparison with currently available intervention strategies for improvement of gait/ambulation in individuals with chronic stroke walking impairment. Methods & materials: A budget impact analysis (BIA) for InTandem was conducted based on a 1-million-member US third-party payer perspective over a 1-year time horizon. Key inputs for the budget impact model were: costs for each intervention strategy (InTandem, physical therapy, self-directed walking and no treatment), HCRU costs for persons with chronic stroke and anticipated HCRU cost offsets due to improvements in gait/ambulatory status as measured by self-selected comfortable walking speed (based on functional ability). In addition to the reference case analysis, a sensitivity analysis was conducted. Results: Based on the reference case, introduction of InTandem was projected to result in overall cost savings of $439,954 in one year. Reduction of HCRU costs (-$2,411,778) resulting from improved walking speeds with InTandem offset an increase in intervention costs (+$1,971,824). Demonstrations of cost savings associated with InTandem were robust and were consistently evident in nearly all scenarios evaluated in the sensitivity analysis (e.g., with increased/decreased patient shares, increased HCRU cost or increased InTandem rental duration). Conclusion: The InTandem system is demonstrated to improve walking and ambulation in adults in the chronic phase of stroke recovery after a five-week intervention period. The BIA predicts that introduction of InTandem will be associated with overall cost savings to the payer.

Feasibility and Proof-of-Concept of Delivering an Autonomous Music-Based Digital Walking Intervention to Persons with Parkinson's Disease in a Naturalistic Setting.

BACKGROUND: Reduced motor automaticity in Parkinson's disease (PD) negatively impacts the quality, intensity, and amount of daily walking. Rhythmic auditory stimulation (RAS), a clinical intervention shown to improve walking outcomes, has been limited by barriers associated with the need for ongoing clinician input. OBJECTIVE: To assess the feasibility, proof-of-concept, and preliminary clinical outcomes associated with delivering an autonomous music-based digital walking intervention based on RAS principles to persons with PD in a naturalistic setting. METHODS: Twenty-three persons with PD used the digital intervention independently for four weeks to complete five weekly 30-minute sessions of unsupervised, overground walking with music-based cues. The intervention progressed autonomously according to real-time gait sensing. Feasibility of independent use was assessed by examining participant adherence, safety, and experience. Intervention proof-of-concept was assessed by examining spatiotemporal metrics of gait quality, daily minutes of moderate intensity walking, and daily steps. Preliminary clinical outcomes were assessed following intervention completion. RESULTS: Participants completed 86.4% of sessions and 131.1% of the prescribed session duration. No adverse events were reported. Gait speed, stride length, and cadence increased within sessions, and gait variability decreased (p < 0.05). Compared to baseline, increased daily moderate intensity walking (mean Δ= +21.44 minutes) and steps (mean Δ= +3,484 steps) occurred on designated intervention days (p < 0.05). Quality of life, disease severity, walking endurance, and functional mobility were improved after four weeks (p < 0.05). CONCLUSIONS: Study findings supported the feasibility and potential clinical utility of delivering an autonomous digital walking intervention to persons with PD in a naturalistic setting.

Auditory and visual category learning in musicians and nonmusicians.

Across three experiments, we compare the ability of amateur musicians and nonmusicians in learning artificial auditory and visual categories that can be described as either rule-based (RB) or information-integration (II) category structures. RB categories are optimally learned using a reflective reasoning process, whereas II categories are optimally learned by integrating information from two stimulus dimensions at a reflexive, predecisional processing stage. We found that musicians have selective advantages for learning auditory RB categories, specifically when they are instructed about the dimensions that define the categories. In Experiment 1, musicians enrolled in a music college demonstrated advantages over nonmusicians in learning auditory RB categories defined on frequency and duration dimensions but did not demonstrate differences in learning auditory II categories or either visual RB or II categories. In Experiment 2, a broader online sample of musicians who were not instructed about the dimensions did not demonstrate any advantage in auditory or visual learning. In Experiment 3, an online sample of musicians when given dimension instructions demonstrated early advantages over nonmusicians for auditory RB but not visual RB categories. Musicians do not demonstrate a global categorization advantage. Musicians' category learning advantage is limited to their modality of expertise, is enhanced with dimension instructions, and is specific to categories that can be described with verbalizable rules. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Cortical Tracking of Speech in Delta Band Relates to Individual Differences in Speech in Noise Comprehension in Older Adults.

OBJECTIVES: Understanding speech in adverse listening environments is challenging for older adults. Individual differences in pure tone averages and working memory are known to be critical indicators of speech in noise comprehension. Recent studies have suggested that tracking of the speech envelope in cortical oscillations <8 Hz may be an important mechanism related to speech comprehension by segmenting speech into words and phrases (delta, 1 to 4 Hz) or phonemes and syllables (theta, 4 to 8 Hz). The purpose of this study was to investigate the extent to which individual differences in pure tone averages, working memory, and cortical tracking of the speech envelope relate to speech in noise comprehension in older adults. DESIGN: Cortical tracking of continuous speech was assessed using electroencephalography in older adults (60 to 80 years). Participants listened to speech in quiet and in the presence of noise (time-reversed speech) and answered comprehension questions. Participants completed Forward Digit Span and Backward Digit Span as measures of working memory, and pure tone averages were collected. An index of reduction in noise (RIN) was calculated by normalizing the difference between raw cortical tracking in quiet and in noise. RESULTS: Comprehension question performance was greater for speech in quiet than for speech in noise. The relationship between RIN and speech in noise comprehension was assessed while controlling for the effects of individual differences in pure tone averages and working memory. Delta band RIN correlated with speech in noise comprehension, while theta band RIN did not. CONCLUSIONS: Cortical tracking by delta oscillations is robust to the effects of noise. These findings demonstrate that the magnitude of delta band RIN relates to individual differences in speech in noise comprehension in older adults. Delta band RIN may serve as a neural metric of speech in noise comprehension beyond the effects of pure tone averages and working memory.

Better late than never (or early): Music training in late childhood is associated with enhanced decision-making.

Decision-making is critical to everyday life. Here we ask: to what extent does music training benefit decision-making? Supported by strong associations between music training and enhanced cross-domain skills, we hypothesize that musicians may show decision-making advantages relative to non-musicians. Prior work has also argued for a "critical period" for cross-domain plasticity such that beginning music training early enhances sensorimotor brain regions that mature early in life. Given that brain regions supporting decision-making begin maturing late in childhood, we hypothesized that an advantage in decision-making may only be present in musicians who began music training later in childhood. To test this hypothesis, young adults who began music training before and after 8 years of age (early-trained musicians, ET; late-trained musicians, LT, respectively) and non-musicians (NM) performed a decision-making task. We found a decision-making advantage in LT relative to ET and NM. To better understand the mechanism of the LT advantage, we conducted computational modeling on participant responses and found that LT were less biased by recent outcomes and incorporated longer strings of outcomes when deciding among the choice options. These results tentatively suggest that music training may confer decision-making enhancements, and carry strong implications for the utility of music training in childhood.

Audio-Visual and Meaningful Semantic Context Enhancements in Older and Younger Adults.

Speech perception is critical to everyday life. Oftentimes noise can degrade a speech signal; however, because of the cues available to the listener, such as visual and semantic cues, noise rarely prevents conversations from continuing. The interaction of visual and semantic cues in aiding speech perception has been studied in young adults, but the extent to which these two cues interact for older adults has not been studied. To investigate the effect of visual and semantic cues on speech perception in older and younger adults, we recruited forty-five young adults (ages 18-35) and thirty-three older adults (ages 60-90) to participate in a speech perception task. Participants were presented with semantically meaningful and anomalous sentences in audio-only and audio-visual conditions. We hypothesized that young adults would outperform older adults across SNRs, modalities, and semantic contexts. In addition, we hypothesized that both young and older adults would receive a greater benefit from a semantically meaningful context in the audio-visual relative to audio-only modality. We predicted that young adults would receive greater visual benefit in semantically meaningful contexts relative to anomalous contexts. However, we predicted that older adults could receive a greater visual benefit in either semantically meaningful or anomalous contexts. Results suggested that in the most supportive context, that is, semantically meaningful sentences presented in the audiovisual modality, older adults performed similarly to young adults. In addition, both groups received the same amount of visual and meaningful benefit. Lastly, across groups, a semantically meaningful context provided more benefit in the audio-visual modality relative to the audio-only modality, and the presence of visual cues provided more benefit in semantically meaningful contexts relative to anomalous contexts. These results suggest that older adults can perceive speech as well as younger adults when both semantic and visual cues are available to the listener.

Effect of explicit dimensional instruction on speech category learning.

Learning nonnative speech categories is often considered a challenging task in adulthood. This difficulty is driven by cross-language differences in weighting critical auditory dimensions that differentiate speech categories. For example, previous studies have shown that differentiating Mandarin tonal categories requires attending to dimensions related to pitch height and direction. Relative to native speakers of Mandarin, the pitch direction dimension is underweighted by native English speakers. In the current study, we examined the effect of explicit instructions (dimension instruction) on native English speakers' Mandarin tone category learning within the framework of a dual-learning systems (DLS) model. This model predicts that successful speech category learning is initially mediated by an explicit, reflective learning system that frequently utilizes unidimensional rules, with an eventual switch to a more implicit, reflexive learning system that utilizes multidimensional rules. Participants were explicitly instructed to focus and/or ignore the pitch height dimension, the pitch direction dimension, or were given no explicit prime. Our results show that instruction instructing participants to focus on pitch direction, and instruction diverting attention away from pitch height, resulted in enhanced tone categorization. Computational modeling of participant responses suggested that instruction related to pitch direction led to faster and more frequent use of multidimensional reflexive strategies and enhanced perceptual selectivity along the previously underweighted pitch direction dimension.

Enhanced cognitive and perceptual processing: a computational basis for the musician advantage in speech learning.

Long-term music training can positively impact speech processing. A recent framework developed to explain such cross-domain plasticity posits that music training-related advantages in speech processing are due to shared cognitive and perceptual processes between music and speech. Although perceptual and cognitive processing advantages due to music training have been independently demonstrated, to date no study has examined perceptual and cognitive processing within the context of a single task. The present study examines the impact of long-term music training on speech learning from a rigorous, computational perspective derived from signal detection theory. Our computational models provide independent estimates of cognitive and perceptual processing in native English-speaking musicians (n = 15, mean age = 25 years) and non-musicians (n = 15, mean age = 23 years) learning to categorize non-native lexical pitch patterns (Mandarin tones). Musicians outperformed non-musicians in this task. Model-based analyses suggested that musicians shifted from simple unidimensional decision strategies to more optimal multidimensional (MD) decision strategies sooner than non-musicians. In addition, musicians used optimal decisional strategies more often than non-musicians. However, musicians and non-musicians who used MD strategies showed no difference in performance. We estimated parameters that quantify the magnitude of perceptual variability along two dimensions that are critical for tone categorization: pitch height and pitch direction. Both musicians and non-musicians showed a decrease in perceptual variability along the pitch height dimension, but only musicians showed a significant reduction in perceptual variability along the pitch direction dimension. Notably, these advantages persisted during a generalization phase, when no feedback was provided. These results provide an insight into the mechanisms underlying the musician advantage observed in non-native speech learning.