Compensatory Patterns Research Articles

Long-range RNA structures in the human transcriptome beyond evolutionarily conserved regions.

RNA structure has been increasingly recognized as a critical player in the biogenesis and turnover of many transcripts classes. In eukaryotes, the prediction of RNA structure by thermodynamic modeling meets fundamental limitations due to the large sizes and complex, discontinuous organization of eukaryotic genes. Signatures of functional RNA structures can be found by detecting compensatory substitutions in homologous sequences, but a comparative approach is applicable only within conserved sequence blocks. Here, we developed a computational pipeline called PHRIC, which is not limited to conserved regions and relies on RNA contacts derived from RNA in situ conformation sequencing (RIC-seq) experiments. It extracts pairs of short RNA fragments surrounded by nested clusters of RNA contacts and predicts long, nearly perfect complementary base pairings formed between these fragments. In application to a panel of RIC-seq experiments in seven human cell lines, PHRIC predicted ~12,000 stable long-range RNA structures with equilibrium free energy below -15 kcal/mol, the vast majority of which fall outside of regions annotated as conserved among vertebrates. These structures, nevertheless, show some level of sequence conservation and remarkable compensatory substitution patterns in other clades. Furthermore, we found that introns have a higher propensity to form stable long-range RNA structures between each other, and moreover that RNA structures tend to concentrate within the same intron rather than connect adjacent introns. These results for the first time extend the application of proximity ligation assays to RNA structure prediction beyond conserved regions.

Compensatory advantage after the first year at university in the Catalan system: between continuing, transferring and dropping out

ABSTRACT Abundant research has shown the influence of social background on university dropout. However, there is little research that considers the different progression options for analysing the structure of the decisions that students make. This article explores the possible alternative decisions of: (1) continuing the initial degree course chosen; (2) persisting but transferring to other degrees or institutions; (3) dropping out of university. To this effect, we seek whether the decision structure follows a compensatory advantage pattern, according to which poor performance during the first year at university unequally affects students from low and high social backgrounds. The latter compensates for poor results by using alternative strategies to minimise the negative consequences. We analyse longitudinal data from a cohort of students entering any on-site university in the Catalan system in 2012–13 (n = 36909). The results show the importance of performance in predicting university progression decisions. No differences by social origin are perceived in the decisions to continue the same course of study, while differences are observed in dropout and transfer decisions which, for their part, follow a compensatory advantage structure. The results show the need to consider the interaction between performance and social background, and to broaden our view of students’ trajectories.

4 Compensatory Functional Activation During Motion Discrimination in Parkinson’s Disease

Objective:PD patients commonly exhibit executive dysfunction early in the disease course which may or may not predict further cognitive decline over time. Early emergence of visuospatial and memory impairments, in contrast, are more consistent predictors of an evolving dementia syndrome. Most prior studies using fMRI have focused on mechanisms of executive dysfunction and have demonstrated that PD patients exhibit hyperactivation that is dependent on the degree of cognitive impairment, suggestive of compensatory strategies. No study has evaluated whether PD patients with normal cognition (PD-NC) and PD patients with Mild Cognitive Impairment (PD-MCI) exhibit compensatory activation patterns during visuospatial task performance.Participants and Methods:10 PD-NC, 12 PD-MCI, and 14 age and sex-matched healthy controls (HC) participated in the study. PD participants were diagnosed with MCI based on the Movement Disorders Society Task Force, Level II assessment (comprehensive assessment). Functional magnetic resonance imaging (fMRI) was performed during a motion discrimination task that required participants to identify the direction of horizontal global coherent motion embedded within dynamic visual noise under Low and High coherence conditions. Behavioral accuracy and functional activation were evaluated using 3 * 2 analyses of covariance (ANCOVAs) (group [HC, PD-NC, PD-MCI] * Coherence [High vs. Low]) accounting for age, sex, and education. Analyses were performed in R (v4.1.2(Team, 2013)).Results:PD-MCI (0.702± 0.269) patients exhibited significantly lower accuracy on the motion discrimination task than HC (0.853 ± 0.241; p = 0.033) and PD-NC (0.880 ± 0.208; p =0.039). A Group * Coherence interaction was identified in which several regions, including orbitofrontal, posterior parietal and occipital cortex, showed increased activation during High relative to Low coherence trials in the PD patient groups but not in the HC group. HC showed default mode deactivation and frontal-parietal activation during Low relative to High coherence trials that was not evident in the patient groups.Conclusions:PD-MCI patients exhibited worse visuospatial performance on a motion discrimination task than PD-NC and HC participants and exhibited hyperactivation of the posterior parietal and occipital regions during motion discrimination, suggesting possible compensatory activation.

Role of kinetic chain in sports performance and injury risk: a narrative review.

The kinetic chain refers to the body's intricate coordination of various segments to perform a specific activity involving precise positioning, timing, and speed. This process is based on task-oriented and activity-specific pre-programmed muscle activation patterns enhanced by repeated practice. It demands muscular eccentric strength, joint flexibility, and musculotendinous elastic energy storage. The body core (lumbopelvic-hip complex) forms the kinetic chains' central point of activities in most sports because it facilitates load transfers to and from the limbs. The kinetic chain relationship with fascia, peripheral nerves, and tensegrity is fundamental to holistic human body movements. The kinetic chain function demands neuromuscular, sensorimotor, and neurocognitive control. Any blockage or defect in the kinetic chain can develop compensatory patterns, high demands on distal parts, and overuse and overload injuries. Taking a holistic approach and evaluating the integrity of the kinetic chain in athletes can significantly enhance efforts to improve sports performance and mitigate injury risk.

Privatization of preschool education: The implications for educational inequalities in cross-national perspective

Preschool education is regarded by many researchers and policymakers as a potential equalizer of educational opportunities. Yet, cross-national research shows that there exist large variations in the equalizing effects of preschool education across countries. In this paper, we study to what extent the national level of privatization of the preschool sector can explain these cross-national differences by examining its impact on the equalizing effects of preschool education. For this purpose, we use data from the Progress in International Reading Literacy Study 2016 for 24 countries. The results show that having spent more time in preschool is more strongly associated with primary school achievements for children of disadvantaged families. We find some modest support that this compensatory pattern—in which preschool compensates for a reduced set of resources in the home environment—is somewhat weaker in societies with higher levels of privatization, though not reaching conventional standards of statistical significance. The study highlights the relevance of considering the impact of national preschool settings on the distribution of preschool benefits across children with varying socioeconomic backgrounds.

Restoring natural upper limb movement through a wrist prosthetic module for partial hand amputees

BackgroundMost partial hand amputees experience limited wrist movement. The limited rotational wrist movement deteriorates natural upper limb system related to hand use and the usability of the prosthetic hand, which may cause secondary damage to the musculoskeletal system due to overuse of the upper limb affected by repetitive compensatory movement patterns. Nevertheless, partial hand prosthetics, in common, have only been proposed without rotational wrist movement because patients have various hand shapes, and a prosthetic hand should be attached to a narrow space.MethodsWe hypothesized that partial hand amputees, when using a prosthetic hand with a wrist rotation module, would achieve natural upper limb movement muscle synergy and motion analysis comparable to a control group. To validate the proposed prototype design with the wrist rotation module and verify our hypothesis, we compared a control group with partial hand amputees wearing hand prostheses, both with and without the wrist rotation module prototype. The study contained muscle synergy analysis through non-negative matrix factorization (NMF) using surface electromyography (sEMG) and motion analyses employing a motion capture system during the reach-to-grasp task. Additionally, we assessed the usability of the prototype design for partial hand amputees using the Jebsen-Taylor hand function test (JHFT).ResultsThe results showed that the number of muscle synergies identified through NMF remained consistent at 3 for both the control group and amputees using a hand prosthesis with a wrist rotation module. In the motion analysis, a statistically significant difference was observed between the control group and the prosthetic hand without the wrist rotation module, indicating the presence of compensatory movements when utilizing a prosthetic hand lacking this module. Furthermore, among the amputees, the JHFT demonstrated a greater improvement in total score when using the prosthetic hand equipped with a wrist rotation module compared to the prosthetic hand without this module.ConclusionIn conclusion, integrating a wrist rotation module in prosthetic hand designs for partial hand amputees restores natural upper limb movement patterns, reduces compensatory movements, and prevent the secondary musculoskeletal. This highlights the importance of this module in enhancing overall functionality and quality of life.

Exploring velar function in speech: An integrated approach using nasometry and high-speed nasopharyngoscopy

It is well established that coupling between the oral and nasal cavities is controlled by velopharyngeal opening and closing movements and that coarticulatory patterns in these movements can affect both the intelligibility and the naturalness of speech. In addition, poor control can cause individuals to develop undesirable compensatory patterns. Most studies of these patterns have relied on indirect methods to assess both extent and timing of movement due to the difficulty of direct observation of the velopharyngeal port. This study focused on the correlation between indirect and direct methods of assessing both timing and magnitude of velopharyngeal opening for coarticulation using complementary data from nasometry and a novel technique – high-speed nasopharyngoscopy. Nasometry measures the ratio of distinct nasal and oral cavity outflow to determine the degree of nasality in speech. High-speed nasopharyngoscopy captures images of the nasopharyngeal region and can resolve velar motion during speech. By aligning these data, we can infer the functional changes of the velopharyngeal port and show the correlation between its status and resulting acoustic effects. Preliminary findings replicate previous work on coarticulatory patterns associated with prosodic structure and low versus high vowels. This work will illuminate how variability in velar function affects phonetic outputs.

A deep learning system to monitor and assess rehabilitation exercises in home-based remote and unsupervised conditions

In the domain of physical rehabilitation, the progress in machine learning and the availability of cost-effective motion capture technologies have paved the way for innovative systems capable of capturing human movements, automatically analyzing recorded data, and evaluating movement quality.This study introduces a novel, economically viable system designed for monitoring and assessing rehabilitation exercises. The system enables real-time evaluation of exercises, providing precise insights into deviations from correct execution. The evaluation comprises two significant components: range of motion (ROM) classification and compensatory pattern recognition. To develop and validate the effectiveness of the system, a unique dataset of 6 resistance training exercises was acquired.The proposed system demonstrated impressive capabilities in motion monitoring and evaluation. Notably, we achieved promising results, with mean accuracies of 89% for evaluating ROM-class and 98% for classifying compensatory patterns.By complementing conventional rehabilitation assessments conducted by skilled clinicians, this cutting-edge system has the potential to significantly improve rehabilitation practices. Additionally, its integration in home-based rehabilitation programs can greatly enhance patient outcomes and increase access to high-quality care.

Kinematic analysis of movement patterns during a reach-and-grasp task in stroke patients.

This study aimed to evaluate the kinematic movement patterns during a reach-and-grasp task in post-stroke patients according to the upper extremity impairment severity. Subacute stroke patients (n = 46) and healthy controls (n = 20) were enrolled in this study. Spatiotemporal and kinematic data were obtained through 3D motion analysis during the reach-and-grasp task. Stroke patients were grouped using the Fugl-Meyer Assessment (FMA) scale, and a comparison of the groups was performed. The severe group showed a significantly longer movement time, lower peak velocity, and higher number of movement units than the mild group during the reach-and-grasp task (p < 0.05). Characteristic compensatory movement patterns, such as shoulder abduction, thoracic posterior tilting, and upward and external rotation were significantly greater during the forward transporting phase in the severe group than in the mild group (p < 0.05). The FMA score was significantly associated with the movement time during the forward transporting phase, number of movement units during the reaching phase, range of shoulder abduction-adduction and wrist flexion-extension movements during the reaching phase, and range of thoracic internal-external rotation during the backward transporting phase (p < 0.05). Post-stroke patients have unique spatiotemporal and kinematic movement patterns during a reach-and grasp-task according to the impairment severity.

Cerebellar EEG source localization reveals age-related compensatory activity moderated by genetic risk for Alzheimer's disease.

The apolipoprotein-E (APOE) ε4 allele is the greatest genetic risk factor for late-onset Alzheimer's disease (AD), but alone it is not sufficiently predictive. Because neuropathological changes associated with AD begin decades before cognitive symptoms, neuroimaging of healthy, cognitively intact ε4 carriers (ε4+) may enable early characterization of patterns associated with risk for future decline. Research in the cerebral cortex highlights a period of compensatory recruitment in elders and ε4+, which serves to maintain cognitive functioning. Yet, AD-related changes may occur even earlier in the cerebellum. Advances in electroencephalography (EEG) source localization now allow effective modeling of cerebellar activity. Importantly, healthy aging and AD are associated with declines in both cerebellar functions and executive functioning (EF). However, it is not known whether cerebellar activity can detect pre-symptomatic AD risk. Thus, the current study analyzed cerebellar EEG source localization during an EF-dependent stop-signal task (i.e., inhibitory control) in healthy, intact older adults (Mage = 80 years; 20 ε4+, 25 ε4-). Task performance was comparable between groups. Older age predicted greater activity in left crus II and lobule VIIb during the P300 window (i.e., performance evaluation), consistent with age-related compensation. Age*ε4 moderations specifically showed that compensatory patterns were evident only in ε4-, suggesting that cerebellar compensatory resources may already be depleted in healthy ε4+ elders. Thus, the posterolateral cerebellum is sensitive to AD-related neural deficits in healthy elders. Characterization of these patterns may be essential for the earliest possible detection of AD risk, which would enable critical early intervention prior to symptom onset.

Combining spinal neuromodulation and activity based neurorehabilitation therapy improves sensorimotor function in cerebral palsy.

Motor dysfunction in individuals with cerebral palsy (CP) such as the inability to initiate voluntary movements, walking with compensatory movement patterns, and debilitating spasticity is due to the aberrant neural connectivity between the brain and spinal cord. We tested the efficacy of noninvasive spinal cord neuromodulation (SCiP™, SpineX Inc.) with activity-based neurorehabilitation therapy (ABNT) in improving the sensorimotor function in six children with CP. Children received 8 weeks of either SCiP™ or sham therapy with ABNT (n = 3 per group). At the end of 8 weeks, all participants received 8 weeks of SCiP™ therapy with ABNT. Follow up assessments were done at week 26 (10 weeks after the last therapy session). Sensorimotor function was measured by the Gross Motor Function Measure 88 (GMFM88) test. We observed minimal change in sham group (mean 6% improvement), however, eight weeks of SCiP™ therapy with ABNT resulted in statistically and clinically relevant improvement in GMFM88 scores (mean 23% increase from baseline). We also observed reduced scores on the modified Ashworth scale only with SCiP™ therapy (-11% vs. +5.53% with sham). Similar improvements were observed in sham group but only after the cross over to SCiP™ therapy group at the end of the first eight weeks. Finally, sixteen weeks of SCiP™ therapy with ABNT resulted in further improvement of GMFM88 score. The improvement in GMFM88 scores were maintained at week 26 (10 weeks after the end of therapy), suggesting a sustained effect of SCiP™ therapy.

Above knee socket prosthesis use changes proximal femur morphology.

Patients with transfemoral amputation (TFA) are up to six times more likely to develop hip osteoarthritis (OA) in either or both the intact and residual limb, which is primarily attributed to habitually altered joint loading due to compensatory movement patterns. However, joint loading patterns differ between limbs, which confounds the understanding of loading-induced OA etiology across limbs. It remains unknown if altered loading due to amputation results in bony shape changes at the hip, which is a known etiological factor in the development of hip OA. Retrospective computed tomography images were collected of the residual limb for 31 patients with unilateral TFA (13F/18M; age: 51.7±9.9 y/o; time since amputation: 13.7±12.4years) and proximal femur for a control group of 29 patients (13F/16M; age: 42.0±12.27years) and used to create 3D geometries of the proximal femur. Femoral 3D geometric variation was quantified using statistical shape modeling (SSM), a computational tool which placed 2048 corresponding particles on each geometry. Independent modes of variation were created using principal component analysis. 2D radiographic measures of the proximal femur, including common measures such as α-angle, head neck offset, and neck shaft angle, were quantified on digitally reconstructed radiographs (DRRs). SSM results were then compared to 2D measures using Pearson correlation coefficients (r). Two-sample t-tests were used to determine if there were significant differences between the TFA and control group means of 2D radiographic measurements (p<0.05). Patients with TFA had greater femoral head asphericity within the SSM, which was moderately correlated to head-neck offset (r=-0.54) and α-angle (r=0.63), as well as greater trochanteric torsion, which was strongly correlated to the novel radiographic measure of trochanteric torsion (r=-0.78), compared to controls. For 2D measures, the neck-shaft angle was smaller in the TFA group compared to the control group (p=0.01) while greater trochanter height was larger in the TFA group compared to the control group (p=0.04). These results indicate altered loading from transfemoral prosthesis use changes proximal femur bony morphology, including femoral head asphericity and greater trochanter changes. Greater trochanter morphologic changes, though not a known factor to OA, affect moment arm and line of action of the primary hip abductors, the major muscles which contribute to joint loading and hip stability. Thus, chronic altered loading of the amputated limb hip, whether under- or overloading, results in bony changes to the proximal femur which may contribute to the etiological progression and development of OA.

Displaced center of pressure on the treated side in individuals with essential tremor after radiofrequency ablation: a longitudinal case-control study.

Essential tremor (ET) is a common involuntary movement disorder (IMD). Radiofrequency ablation (RFA) targeting the ventral intermediate nucleus (Vim) of the thalamus is a stereotactic neurosurgery performed in individuals with ET when pharmacotherapy is no longer effective. Though the reasons remain largely unclear, certain adverse events are known to appear post-RFA. These may be due to functional changes in the Vim, related to RFA-induced tremor reduction, or an adverse reaction to compensatory movement patterns used to perform movements in the presence of tremor symptoms. This study aimed to understand the characteristics of post-RFA symptoms in individuals with ET. In a longitudinal case-control study, we compared post-RFA symptoms between individuals with ET who underwent Vim-targeted RFA and those with IMD who underwent non-Vim-targeted RFA. Symptoms were compared preoperatively and 1-week and 1-month postoperatively. Quantitative assessments included center-of-pressure (COP) parameters, grip strength, Mini-Mental State Examination, two verbal fluency tests, and three types of physical performance assessments (upper extremity ability, balance ability, and gait ability). Individuals with ET after RFA showed horizontal displacements of the COP to the treated side (the dominant side of the RFA target's hemisphere) at 1-week postoperatively compared to the preoperative period. The horizontal COP displacement was associated with balance dysfunction related to postural stability post-RFA. Other COP parameters did not significantly differ between the ET and IMD groups. COP displacement to the treated side may be due to a time lag in adjusting postural holding strategies to the long-standing lateral difference in tremor symptoms associated with tremor improvement after RFA.

The predictive role of early childhood dysregulation profile on the parallel growth trajectories of reading and math performance across elementary and middle school

This study examined the heterogeneity in the co-developmental trajectories of reading and math performance (i.e., parallel changes in the initial scores and growth patterns) and identified the number, size and shape of the co-developmental trajectory across elementary and middle schools. In addition, this investigation focused on how an early childhood dysregulation profile (DP; indexed by a high co-occurrence of emotional, behavior, and attention problems) was associated with distinct co-developmental trajectories of reading and math performance. Specifically, we examined whether early childhood DP level can predict (a) membership assignment into each distinct co-development group and (b) variability in initial scores and changes in growth with each distinct co-development group. Participants were 784 academically at-risk students (47 % girls) predominantly from low socioeconomic status families who were recruited in first grade (Mean age = 6.57 years) and followed annually through the final year of middle school (ninth grade). Results revealed two distinct co-developmental trajectories of reading and math performance, including (a) a lower initial reading (higher increasing) and higher initial math (lower increasing) class (85.3 %) and (b) a lower initial math (higher increasing) and higher initial reading (lower increasing) class (14.7 %). Our results provided evidence for the compensatory pattern of co-developmental trajectories, indicating initial lower skills grow at a faster rate than the initial high. Further, early childhood DP was not associated with the membership assignment for these two distinct classes, which means that regardless of children’s early DP level, they have equal chances to be assigned to each of the classes. However, children with higher parent and teacher-reported DP in first grade demonstrated lower initial scores and a slower improvement rate in both classes after controlling for kindergarten literacy skills, gender, ethnicity, intelligence, socioeconomic status, and grade retention. Our study findings demonstrated (a) substantial heterogeneity in the co-developmental trajectories of reading and math performance across elementary and middle school ages; and (b) the importance of promoting self-regulation beginning in early childhood, especially for academically at-risk children in families facing economic challenges.

Matthew effects in reading and mathematics: Examining developmental patterns in population data

This study examined whether Matthew effects were evident in developmental patterns of reading and mathematics skills from middle childhood to adolescence. We obtained standardized reading and mathematics scores at Grades 3, 5, 7 and 9 for full cohorts of students in two Australian states, NSW (N = 88,958, 48% female) and Victoria (N = 65,984, 49% female). Latent growth curve models were used to identify the best-fitting longitudinal trajectories of reading and mathematics, and to examine whether cumulative (i.e. a Matthew effect), compensatory, or stable interindividual differences characterized development in each domain. For both reading and mathematics, and in both samples, growth decelerated as grade levels increased, with latent basis models fitting the data better than linear models. Negative intercept-slope covariances, and decreasing variances at increasing grades in both domains indicated compensatory growth patterns, rather than cumulative patterns or Matthew effects. These results indicate that students with below average achievement at Grade 3 make greater gains to Grade 9 than their initially higher-achieving peers. Modeling growth trajectories in two longitudinal population datasets allows strong tests of theorized growth patterns for both reading and mathematics, and presents insights about developmental change in academic skills from middle childhood to adolescence.

Design and evaluation of an independent 4-week, exosuit-assisted, post-stroke community walking program.

Chronic impairment in the paretic ankle following stroke often requires that individuals use compensatory patterns such as asymmetric propulsion to achieve effective walking speeds needed for community engagement. Ankle exosuit assistance can provide ankle biomechanical benefit in the lab, but such environments inherently limit the amount of practice available. Community walking studies without exosuits can provide massed practice and benefit walking speed but are limited in their ability to assist proper mechanics. In this study, we combined the positive aspects of community training with those of exosuit assistance. We developed and evaluated a community Robotic Exosuit Augmented Locomotion (cREAL) program. Four participants in the chronic stage of stroke independently used our community ankle exosuit for walking in the community 3-5 days/week for 4 weeks. We performed lab evaluations before and after the 4-week program. Two participants significantly improved their unassisted paretic propulsion by an average of 27% after the program and walked on average 4001 steps/day more in the week following the program. Despite the small number of participants, this study provides preliminary evidence for the potential of exosuits to augment gait training and rehabilitation in the community.

“Three pills” (cognitive reappraisal × social support × cognitive flexibility) and their impact on ADHD symptoms in early adolescence: Synergistic or compensatory effect?

Converging and compelling evidence has isolated how three malleable “pills” (cognitive reappraisal, social support, and cognitive flexibility) affect the manifestation of ADHD symptoms, but the complex combined effect over time has not been sufficiently addressed. The present research leveraged a strength-based “strategy × situation × person interaction” model to investigate how cognitive reappraisal (strategy), social support from friend (situation), and cognitive flexibility (person) uniquely and interactively impact teacher-rated ADHD symptoms in a typically developing early adolescent sample. In this three-wave multiple-method prospective study, 194 adolescents (Meanage = 11.39; 53.1 % girls) participated. At Time 1, adolescents self-rated cognitive reappraisals; at Time 2, adolescents completed the social support questionnaire and a computerized cognitive flexibility task. Meanwhile, teachers estimated their students' ADHD symptoms at both Time 1 and Time 3. The current study suggests that “more is not always better.” The seemingly beneficial socioemotional and cognitive characteristics in isolation are important to mitigate the manifestations of ADHD symptoms, but when these characteristics work together, they produce a compensatory (instead of synergistic) interaction effect. Specifically, cognitive reappraisal and social support from friend are compensatory and protect young adolescents from severe manifestations of ADHD symptoms. Such a compensatory pattern is especially pronounced for those exhibiting poor cognitive flexibility performance.

Exploring Linkages Between Mother-Child and Sibling Relationship Quality and Prosocial Behavior Between School-Aged and Adolescent Siblings.

The present study investigated the degree to which the quality of sibling relationships interacted with the quality of mother-child relationships to concurrently predict prosocial behavior between school-aged siblings while taking age spacing into account. Forty-five families with two school-aged siblings were recruited from the community. Prosocial behavior was coded from unstructured laboratory observation of sibling interaction. Both children reported on the quality of their sibling relationships; the quality of mother-child relationships was assessed by coding laboratory observation of mother-child interaction, conducted separately with each sibling. A compensatory pattern was found; higher warmth between widely spaced siblings was associated with greater sibling prosocial behavior when maternal positivity was low, and also when maternal negativity was high. These compensatory patterns did not occur for siblings closer in age. Findings suggested that sibling dynamics and relational roles play an important function in children's prosocial development. Results were discussed within family systems frameworks.

An Ultrasound Investigation of Tongue Dorsum Raising in Children with Cleft Palate +/- Cleft Lip.

This study aimed to determine whether increased raising of the back of the tongue is evident in children with repaired cleft palate with or without cleft lip (CP+/-CL). We hypothesized that children with CP+/-CL would show increased raising of the tongue dorsum, a compensatory pattern. Secondary data analysis of mid-sagittal ultrasound tongue imaging data from 31 children with CP+/-CL and 29 typically developing children were used. We annotated the consonants /ʃ, t, s, k/ at the point of maximum constriction in an /aCa/ environment. Children with CP+/-CL said the tokens 10 times, typically developing children said them once. We automatically fitted splines to the tongue contour and extracted the Dorsum Excursion Index (DEI) for each consonant. This metric measures the relative use of the tongue dorsum, with more posterior consonants having higher values. We compared DEI values across groups and consonants using a linear mixed effects model. DEI was predicted by the interaction of consonant (baseline: /ʃ/) and speaker type (baseline: TD), including by-speaker random slopes for consonant and random intercepts for speaker. Overall DEI was not higher in children with CP+/-CL compared to typically developing children. Between groups the only significant difference was the position of /k/ relative to /ʃ/, where the difference between these two consonants was smaller in the children with CP+/-CL. There was no support for the hypothesis that increased raising of the tongue dorsum is a common characteristic in children with repaired CP+/-CL. However, individual children may present with this pattern.

Slipping while counting: gaze–gait interactions during perturbed walking under dual-task conditions

Walking is a complex task. To prevent falls and injuries, gait needs to constantly adjust to the environment. This requires information from various sensory systems; in turn, moving through the environment continuously changes available sensory information. Visual information is available from a distance, and therefore most critical when negotiating difficult terrain. To effectively sample visual information, humans adjust their gaze to the terrain or—in laboratory settings—when facing motor perturbations. During activities of daily living, however, only a fraction of sensory and cognitive resources can be devoted to ensuring safe gait. How do humans deal with challenging walking conditions when they face high cognitive load? Young, healthy participants (N = 24) walked on a treadmill through a virtual, but naturalistic environment. Occasionally, their gait was experimentally perturbed, inducing slipping. We varied cognitive load by asking participants in some blocks to count backward in steps of seven; orthogonally, we varied whether visual cues indicated upcoming perturbations. We replicated earlier findings on how humans adjust their gaze and their gait rapidly and flexibly on various time scales: eye and head movements responded in a partially compensatory pattern and visual cues mostly affected eye movements. Interestingly, the cognitive task affected mainly head orientation. During the cognitive task, we found no clear signs of a less stable gait or of a cautious gait mode, but evidence that participants adapted their gait less to the perturbations than without secondary task. In sum, cognitive load affects head orientation and impairs the ability to adjust to gait perturbations.