Within-subject Variables Research Articles

Cues to land softly and quietly result in acute reductions in ground reaction force loading rates in runners

BackgroundA common gait retraining goal for runners is reducing vertical ground reaction force (GRF) loading rates (LRs), which have been associated with injury. Many gait retraining programs prioritize an internal focus of attention, despite evidence supporting an external focus of attention when a specific outcome is desired (e.g., LR reduction). Research QuestionDoes an external focus of attention (using cues for quiet, soft landings) result in comparable reductions in LRs to those achieved using a common internal focus (forefoot striking while barefoot)? MethodsThis observational study included 37 injured runners (18 male; mean age 36 (14) years) at the OMITTED Running Center. Runners wore inertial measurement units over the distal-medial tibia while running on an instrumented treadmill at a self-selected speed. Data were collected for three conditions: 1) Shod-Control (wearing shoes, without cues); 2) Shod-Quiet (wearing shoes, cues for quiet, soft landings); and 3) Barefoot-FFS (barefoot, cues for forefoot strike (FFS)). Within-subject variables were compared across conditions: vertical instantaneous loading rate (LR, primary outcome); vertical stiffness during initial loading; peak vertical GRF; peak vertical tibial acceleration (TA); and cadence. ResultsVertical LR, stiffness, and TA were lower in the Shod-Quiet compared to Shod-Control p < 0.001). Peak vertical GRF and cadence were not different between Shod-Quiet and Shod-Control. Reductions in stiffness and LR were similar between Shod-Quiet and Barefoot-FFS, and GRF in Barefoot-FFS remained similar to both shod conditions. However, runners demonstrated additional reductions in TA and increased cadence when transitioning from Shod-Quiet to the Barefoot-FFS condition (p < 0.05). SignificanceThese results suggests that a focus on quiet, soft landings may be an effective gait retraining method for future research.

The Association of APOE ε4 Allele with Retinal Layer Thickness and Microvasculature in Older Adults: Optic Nerve Decline and Cognitive Change Study.

To investigate the relationship between the apolipoprotein E (APOE) ε4 allele and retinal structural and vascular characteristics in older adult participants from several research studies. We also studied the relationship between these structural and vascular characteristics with multifocal visual evoked potential (mfVEP) indices, neuropsychological parameters and MRI brain volumes in these participants. In this study, 109 participants with a mean (SD) age of 67.1 (9.0) years were recruited. Participants were classified as APOE ε4 carriers or non-carriers based on the presence or absence of the ε4 allele. Baseline measurements included peripapillary retinal nerve fibre layer optical coherence tomography (RNFL OCT), and OCT-angiography (OCT-A) for evaluation of the retinal layer thickness and vessel density (VD) parameters. A multifocal visual evoked potential (mfVEP) test, including amplitude and latency, was used to assess the visual pathway function. Finally, cognitive function was evaluated using a battery of neuropsychological tests. OCT-A images were analysed in ImageJ to quantify VD in the superficial and deep vascular plexus and the size of the foveal avascular zone (FAZ). The relationship between carriers of APOE ε4 allele and these ocular parameters was analysed using generalised estimating equation (GEE) models and data adjusted for age, sex and inter-eye differences as within-subject variables (p < 0.05). Twenty-four participants were APOE ε4 carriers. Temporal RNFL thickness was decreased in APOE ε4 carriers (p < 0.01). Vessel density between carriers and non-carriers was not significantly different at either the superficial or deep level. The FAZ area was significantly smaller in ε4 carriers in both superficial (p < 0.01) and deep layers (p < 0.003). Retinal abnormalities were present in participants with increased genetic risk of dementia due to presence of the ε4 allele. These findings provide preliminary evidence for their potential role in the diagnosis of dementia.

Effects of task structure and attribution target on responsibility attributions in human–robot interaction

Responsibility attribution refers to beliefs about the cause of an event or outcome. This study investigates the effects of cooperation and competition on responsibility attributions after success and failure in human–robot interaction. A 2 × 2 × 2 mixed-design experiment was conducted, with task structure (cooperation vs. competition) and attribution target (self vs. robot) as within-subject variables and task outcome (win vs. lose) as a between-subject variable. Forty students from a university campus participated in the experiment. They cooperated with or competed against a humanoid robot in a picture memory game whose outcome either exceeded (success) or did not reach (failure) an expected outcome. Afterward, participants allocated the causal responsibility between themselves and the humanoid robot for a specified performance success or failure. It was found that participants attributed more responsibility for success to themselves than to the humanoid robot, and such self-serving bias was greater in competitive than in cooperative structures. Additionally, participants attributed more responsibility for failure to themselves than to the humanoid robot in cooperative structures but not in competitive structures. Moreover, the competitiveness index of unsuccessful participants moderated the relationship between the task structure and the differential responsibility attribution between the self and the robot. Furthermore, participants evaluated the humanoid robot more positively in cooperative than competitive structures. Finally, participants had higher accuracy in cooperative structures, although they subjectively perceived that they performed better in competitive structures. These findings provide insight to guide people's attributional behavior, task performance, and evaluation of robots in the desired manner from the perspective of task structure design.

Effect of Correcting Peripheral Refractive Errors on Retinal Sensitivity in Younger and Older Healthy Adults.

Retinal sensitivity decreases with age and age-related eye diseases. Peripheral retinal sensitivity may also be compromised if the refractive correction is not optimized for peripheral vision. This study aimed to determine the impact of using a peripheral refractive correction on perimetric thresholds and the influence of age and spherical equivalent on this impact. We measured, in 10 younger (20 to 30 years) and 10 older (58 to 72 years) healthy subjects, perimetric thresholds for Goldmann size III stimulus in several test locations along the horizontal meridian of the visual field (eccentricity, 0, ±10, and ±25°), with default central refractive correction and with peripheral refractive corrections as measured with a Hartmann-Shack wavefront sensor. We used analysis of variance to determine the effect of age and spherical equivalent (between-subject variables) and eccentricity and correction method (central vs. eccentricity specific; within-subject variables) on retinal sensitivity. Retinal sensitivity was higher if the eyes were optimally corrected for the concerning test location (P = .008), and the effect of this peripheral correction differed between the younger and older subjects (interaction term between group and correction method: P = .02), primarily because of more myopia in the younger group (P = .003). The average improvement by applying peripheral corrections was 1.4 dB in the older subjects and 0.3 dB in the younger subjects. Peripheral optical correction has a variable impact on retinal sensitivity, and therefore, assessment of retinal sensitivity may be more accurate if peripheral defocus and astigmatism are corrected.

Social Attitude Profiles and Attribution Types Confronting Pandemic COVID-19

This study aimed to analyze the social processes confronted during the COVID-19 pandemic, arguing that social problems should be primarily analyzed to utilize public health policies. The theoretical framework concerns social attitudes of behavior, emotion, and cognition (BEC) and social attribution types of inner and outer crossed by temporal and permanent, as proposed by Weiner (1974). A quasi-experiment research design was processed using a questionnaire which included personal identities designed by between-subject of 221 people sampled, and items of social attitudes profiles and attribution types designed by within-subject of 27 conditions. Factor analysis expounded that all the items be grouped into 8 independent components that corresponded to the items constructed to be evaluated as a successful design. Analyzing within-subject variables, BEC of social attitudes as health, medical, faith, and risk and mental symptoms except that of political were highly negative skewed in distributions. Each of BEC was individualized to compose the related social attitudes. For attribution types, the permanent ones of personal, governmental, and religious, but not medical, were attributed to the epidemic. This study suggested that social attitudes of BEC were adapted to the pandemic and that attribution should be regarded primarily to make policies efficient for public health.

Search Processes in the Exploration of Complex Data under Different Display Conditions

The study investigated user experience, display complexity, display type (tables versus graphs), and task difficulty as variables affecting the user’s ability to navigate through complex visual data. A total of 64 participants, 39 undergraduate students (novice users) and 25 graduate students (intermediate-level users) participated in the study. The experimental design was 2 × 2 × 2 × 3 mixed design using two between-subject variables (display complexity, user experience) and two within-subject variables (display format, question difficulty). The results indicated that response time was superior for graphs (relative to tables), especially when the questions were difficult. The intermediate users seemed to adopt more extensive search strategies than novices, as revealed by an analysis of the number of changes they made to the display prior to answering questions. It was concluded that designers of data displays should consider the (a) type of display, (b) difficulty of the task, and (c) expertise level of the user to obtain optimal levels of performance.

Effects of Visual Cues on Distance Perception in Virtual Environments Based on Object Identification and Visually Guided Action

ABSTRACT In perceiving a virtual environment (VE), distance perception is important in that it affects users’ behaviors and interactions. This study addresses an on-going issue of virtual reality (VR), distance underestimation within a VE. For this purpose, a 2x2x2x5 mixed design was used with two between-subject variables [visual cue for perception (provided and non-provided) and visual cue for action (provided and non-provided)] and two within-subject variables [response measure (verbal estimation and triangulated blind walking) and distance (1 m, 5 m, 10 m, 20 m, and 35 m)]. Sixty-four undergraduate or graduate students participated in the experiment, and a cube was chosen as the target object. The experimental results showed that visual cues for action mitigated distance underestimation and improved the accuracy of perceived distances. In general, distance underestimation was more obvious in the triangulated blind walking than the verbal estimation, and in the action/vista space than personal space, with relatively lower accuracies. Meanwhile, when visual cue for action were provided, the degree of underestimation decreased significantly with higher accuracy particularly in the triangulated blind walking. Although overestimation was found across all the distances in the verbal estimation, overestimation was found only for the personal distance, and underestimation was found for the action/vista distances in the triangulated blind walking. In both response measures, the accuracy of distance perceptions were the worst in the 10 m condition. These findings can be expected to provide insight into the problem of distance underestimation and can help guide design of VEs.

Check-control of inflammation displayed by bone marrow mesenchymal stem cells in rheumatoid arthritis patients.

Background: Mesenchymal stem cells (MSCs) are a promising treatment of different musculoskeletal diseases including osteoarthritis and rheumatoid arthritis (RA). Results from different approaches in this treatment have been not conclusive. Aim: To analyze factors related to interactions between peripheral blood mononuclear cells (PBMCs) and MSCs and the influence of cellular activation. Materials & methods: PBMCs from RA patients and healthy controls (HC) were obtained. MSCs from bone marrow (BM-MSCs) were obtained from six donors. CD4, CD25, CD69 and CD127 expression was measured by flow cytometry. Repeated measures analysis of variance (ANOVA) models were performed using activation, co-culture with BM-MSCs and time of culture (24h, 72h, 6days) as within-subject variables. Results: PBMCs activated and co-cultured with BM-MSCs showed a lower proportion of CD25-positive and CD25high/CD127low-negative cells in both RA and HC. Additionally, a maintained expression of CD69 was also observed in RA and HC when PBMCs were activated and co-cultured with BM-MSCs. Conclusion: Both PBMC activation grade and RA disease activity influence the immunomodulatory effect of BM-MSCs on T-cell activation.

The Effect of Presentation Mode and Production Type on Word Memory for Hearing Impaired Signers.

Production effect (PE) is a memory phenomenon referring to better memory for produced (vocalized) than for non-produced (silently read) items. Reading aloud was found to improve verbal memory for normal-hearing individuals, as well as for cochlear implant users, studying visually and aurally presented material. The present study tested the effect of presentation mode (written or signed) and production type (vocalization or signing) on word memory in a group of hearing impaired young adults, sign-language users. A PE paradigm was used, in which participants learned lexical items by two presentation modes, written or signed. We evaluated the efficacy of two types of productions: vocalization and signing, using a free recall test. Twenty hearing-impaired young adults, Israeli sign language (ISL) users, participated in the study, ten individuals who mainly use manual communication (MC) (ISL as a first language), and ten who mainly use total communication (TC). For each condition, we calculated the proportion of study words recalled. A mixed-design analysis of variance was conducted, with learning condition (written-vocalize, written-signed, and manual-signed) and production type (production and no-production) as within-subject variables, and group (MC and TC) as a between-subject variable. Production benefit was documented across all learning conditions, with better memory for produced over non-produced words. Recall rates were higher when learning written words relative to signed words. Production by signing yielded better memory relative to vocalizing. The results are explained in light of the encoding distinctiveness account, namely, the larger the number of unique encoding processes involved at study, the better the memory benefit.

Changes in English Past Tense Use by Bilingual School-Age Children With and Without Developmental Language Disorder.

The purpose of this study is to examine changes in English past tense accuracy and errors among Spanish-English bilingual children with typical development (TD) and developmental language disorder (DLD). Thirty-three children were tested before and after 1 year to examine changes in clinically relevant English past tense errors using an elicited production task. A mixed-model linear regression using age as a continuous variable revealed a robust effect for age. A 4-way repeated-measures analysis of variance was conducted with age (young, old) and language ability group (TD, DLD) as between-subjects variables, time (Time 1, Time 2) and verb type (regular, irregular, and novel verbs) as within-subject variables, and percent accuracy as the dependent variable. Subsequently, a 4-way repeated-measures analysis of variance was conducted to measure the overall distribution of verb errors across 2 time points. Overall, children produced regular and novel verb past tense forms with higher accuracy than irregular past tense verbs in an elicitation task. Children with TD were more accurate than children with DLD. Younger children made more improvement than older children from Time 1 to Time 2, especially in the regular and novel verb conditions. Bare stem and overregularization were the most common errors across all groups. Errors consisting of stem + ing were more common in children with DLD than those with TD in the novel verb condition. Contrary to an earlier report (Jacobson & Schwartz, 2005), the relative greater difficulty with regular and novel verbs was replaced by greater difficulty for irregular past tense, a pattern consistent with monolingual impairment. Age was a contributing factor, particularly for younger children with DLD who produced more stem + ing errors in the novel verb condition. For all children, and particularly for those with DLD, an extended period for irregular past tense learning was evident. The results support a usage-based theory of language acquisition and impairment.

Effects of the place of articulation of the following consonant on the identification and discrimination of American English vowels by native speakers of Japanese and Korean

Native speakers of Japanese and Korean identified 6 American English monophthongs /i, ɪ, ɛ, ae, ɑ, ʌ/ and discriminated 6 vowel pairs /i/-/ɪ/, /ɛ/-/ɪ/, /ae/-/ɛ/, /ae/-/ɑ/, /ae/-/ʌ/, /ɑ/-/ʌ/ in in /hVt/, /pVt/, /pVn/ and /pVl/ frames. The two groups of listeners' identification and discrimination accuracy were submitted to 2 mixed-design ANOVAs, respectively, with 2 Listener Groups as a between-subject variable, and 6 frames and 6 vowels (or vowel pairs) as within-subject variables. As for identification, a main effect of vowel and frame are both significant (p<.001), and a three-way interaction of listener groups × vowels × frames is also significant (p<.001). Post-hoc pair-wise comparisons revealed that Korean listeners identified /ʌ/ significantly better than Japanese listeners. This is probably because Korean listeners can equate the English vowel to Korean /ʌ/. Japanese listeners' identification accuracy of /i/ is lower before /n/ and /l/, but that of Korean listeners was not affected by the context. As for discrimination, a main effect of the frames and vowel pairs was significant (p<.001). A three-way interaction of the 3 factors was not significant, but all the two-way interactions were significant (p<.001). Post-hoc pair-wise comparisons revealed that Japanese listeners' discrimination accuracy of /i/-/ɪ/ and /ae/-/ɛ/ is lower before /n/ and /l/ than before /t/, while that of Korean listeners was not affected by the context. Korean listeners discriminated /ae/-/ɛ/ least accurately of all the six vowel pairs.

A Feel for Numbers: The Changing Role of Gesture in Manipulating the Mental Representation of an Abacus Among Children at Different Skill Levels.

Abacus mental arithmetic involves the skilled acquisition of a set of gestures representing mathematical algorithms to properly manipulate an imaginary abacus. The present study examined how the beneficial effect of abacus co-thought gestures varied at different skill and problem difficulty levels. We compared the mental arithmetic performance of 6- to 8-year-old beginning (N = 57), intermediate (N = 65), and advanced (N = 54) learners under three conditions: a physical abacus, hands-free (spontaneous gesture) mental arithmetic, and hands-restricted mental arithmetic. We adopted a mixed-subject design, with level of difficulty and skill level as the within-subject independent variables and condition as the between-subject independent variable. Our results showed a clear contrast in calculation performance and gesture accuracy among learners at different skill levels. Learners first mastered how to calculate using a physical abacus and later benefitted from using abacus gestures to aid mental arithmetic. Hand movement and gesture accuracy indicated that the beneficial effect of gestures may be related to motor learning. Beginners were proficient with a physical abacus, but performed poorly and had low gesture accuracy during mental arithmetic. Intermediates relied on gestures to do mental arithmetic and had accurate hand movements, but performed more poorly when restricted from gesturing. Advanced learners could perform mental arithmetic with accurate gestures and scored just as well without gesturing. These findings suggest that for intermediate and advanced learners, motor-spatial representation through abacus co-thought gestures may complement visual-spatial representation of a mental abacus to reduce working memory load.

An Investigation of Driver Behavior on Urban General Road and in Tunnel Areas

The objective of this study is to examine experience-related differences in microscope driving behavior as drivers performed six separate maneuvers, namely 1) driving on general urban roads, 2) approaching a tunnel portal, 3) driving through a tunnel’s threshold zone, 4) driving in the interior tunnel zone, 5) driving in the zone ahead the tunnel exit and 6) driving after the tunnel exit. An on-road experiment was conducted with 20 drivers in two groups. The first group was made up of new licensed drivers, and the second group contained the more experienced drivers. The study consisted of one between-subject (experience) and five within-subject variables (drive environment type). The drivers’ behavior was measured through Mean Glance Duration, AOI Attention Ration, Horizontal Eye Activity, Vertical Eye Activity, Percentage of Eyelid Closure, and Heart Rate Variability. With respect to the relevant psychological measures, the results show that in general more attention is focused on the far left-hand side of the road and the near front road when driving through tunnel areas when compared with driving on general roads. In addition, the psychological measurements indicate that tunnel’s dark narrow environment causes anxiety on driving for lower heart rate variation coefficient (RRCV). New licensed drivers were more severely affected by the tunnel environment than the experienced drivers.

Feasibility, acceptability, and validity of crowdsourcing for collecting longitudinal alcohol use data.

Challenges to conducting longitudinal research include financial, time, and geographic constraints. An emerging sampling method positioned to address these concerns is crowdsourcing. This study evaluated the feasibility, acceptability, and validity of collecting intensive longitudinal alcohol use data with the crowdsourcing platform, Amazon.com's Mechanical Turk (mTurk). Participants (N = 278) recruited from mTurk provided weekly recordings of daily alcohol and soda use over an 18-week period. Construct and external validity was evaluated using generalized linear mixed models describing associations of between-subject (e.g., alcohol use severity) and within-subject (e.g., day of week) variables with prospectively collected alcohol and soda use. High response rates were observed across the 18-week period demonstrating feasibility (64.1%-86.8%). The design was acceptable with 94% of participants indicating they were satisfied with the procedures. Multilevel models supported construct and external validity by replicating expected associations, such as more frequent and heavier drinking by individuals with higher AUDIT scores and on weekends. These effects were specific to alcohol use and did not extend to soda consumption. These data support the feasibility, acceptability, and validity of using mTurk for intensive longitudinal data collection. Future studies may leverage this platform to generate large, geographically diverse samples for prospective behavioral analytic research.

Synaptic proteins in CSF as potential novel biomarkers for prognosis in prodromal Alzheimer\u2019s disease

BackgroundWe investigated whether a panel of 12 potential novel biomarkers consisting of proteins involved in synapse functioning and immunity would be able to distinguish patients with Alzheimer’s disease (AD) and patients with mild cognitive impairment (MCI) from control subjects.MethodsWe included 40 control subjects, 40 subjects with MCI, and 40 subjects with AD from the Amsterdam Dementia Cohort who were matched for age and sex (age 65 ± 5 years, 19 [48%] women). The mean follow-up of patients with MCI was 3 years. Two or three tryptic peptides per protein were analyzed in cerebrospinal fluid using parallel reaction monitoring mass spectrometry. Corresponding stable isotope-labeled peptides were added and used as reference peptides. Multilevel generalized estimating equations (GEEs) with peptides clustered per subject and per protein (as within-subject variables) were used to assess differences between diagnostic groups. To assess differential effects of individual proteins, we included the diagnosis × protein interaction in the model. Separate GEE analyses were performed to assess differences between stable patients and patients with progressive MCI (MCI-AD).ResultsThere was a main effect for diagnosis (p < 0.01) and an interaction between diagnosis and protein (p < 0.01). Analysis stratified according to protein showed higher levels in patients with MCI for most proteins, especially in patients with MCI-AD. Chromogranin A, secretogranin II, neurexin 3, and neuropentraxin 1 showed the largest effect sizes; β values ranged from 0.53 to 0.78 for patients with MCI versus control subjects or patients with AD, and from 0.67 to 0.98 for patients with MCI-AD versus patients with stable MCI. In contrast, neurosecretory protein VGF was lower in patients with AD than in patients with MCI (ß = −0.93 [SE 0.22]) and control subjects (ß = 0.46 [SE 0.19]).ConclusionsOur results suggest that several proteins involved in vesicular transport and synaptic stability are elevated in patients with MCI, especially in patients with MCI progressing to AD dementia. This may reflect early events in the AD pathophysiological cascade. These proteins may be valuable as disease stage or prognostic markers in an early symptomatic stage of the disease.

Neuropsychological outcome after subtemporal versus transsylvian approach for selective amygdalohippocampectomy in patients with mesial temporal lobe epilepsy: a randomised prospective clinical trial

ObjectiveTo compare the effects of different surgical approaches for selective amygdalohippocampectomy in patients with pharmacoresistant mesial temporal lobe epilepsy with regard to the neuropsychological outcome and to replicate an earlier...

Extended Fitts’ model of pointing time in eye-gaze input system - Incorporating effects of target shape and movement direction into modeling

This study attempted to investigate the effects of the target shape and the movement direction on the pointing time using an eye-gaze input system and extend Fitts' model so that these factors are incorporated into the model and the predictive power of Fitts' model is enhanced. The target shape, the target size, the movement distance, and the direction of target presentation were set as within-subject experimental variables. The target shape included: a circle, and rectangles with an aspect ratio of 1:1, 1:2, 1:3, and 1:4. The movement direction included eight directions: upper, lower, left, right, upper left, upper right, lower left, and lower right. On the basis of the data for identifying the effects of the target shape and the movement direction on the pointing time, an attempt was made to develop a generalized and extended Fitts’ model that took into account the movement direction and the target shape. As a result, the generalized and extended model was found to fit better to the experimental data, and be more effective for predicting the pointing time for a variety of human-computer interaction (HCI) task using an eye-gaze input system.

The Effectiveness of Using Stereoscopic 3D for Proportion Estimation in Product Design Education

In product design education, identifying proportion and manipulating proportional relationships are important practices in form-giving training. However, using conventional 2D displays with monocular depth cues to train students with different spatial abilities remains a great challenge. Although, some literature has indicated that stereoscopic 3D (S3D) displays were helpful for depth-related tasks, whether S3D is helpful for proportion estimation is an open question. Therefore, the objective of this research was to study whether using S3D for design department students could assist them in improving their ability to interpret the proportions of products. The independent variables of the experiment included spatial ability, task complexity, and display mode. Spatial ability was a between-subject variable. Students aged 20–25 years were recruited as participants and were categorized into high-, moderate-, and low-performance groups depending on their score on a spatial ability scale. Task complexity and display mode were within-subject variables. In the experiment, three chair styles were used as samples. Digital models of three chairs with distinct proportions were displayed in two conditions: 2D mode with monocular depth cues and S3D mode. Participants were asked to compare the proportions of a physical chair and three digital chairs and then select the digital chair with the correct proportions in the 2D and S3D modes. The dependent variable were the score of selecting the 3D digital models with correct proportions compared to the physical objects. The result indicated that students could perceive proportions more accurately in the S3D mode than in the 2D mode. In particular, when using S3D, participants with low spatial ability demonstrated overall performance that was equal to that of participants with high spatial ability.

Can Motive-Related Imagery Make School Tasks More Appealing?

Abstract. According to recent research ( Eccles, 1999 ; GEOlino-UNICEF-Kinderwertemonitor, 2014), young people are particularly interested in issues related to affiliation, achievement, or power. We suggest that tasks that raise these issues should be more motivating than tasks that do not raise these topics. To test this hypothesis, we enriched the tasks of common mathematics and German textbooks with affiliation, achievement, or power issues. In four experiments, fifth-graders rated how much they would like to work on the tasks (n = 31 for essay tasks, n = 76 for math tasks) and how confident they were about solving them (n = 56 for essay tasks, n = 60 for math tasks). Motive-related issues were within-subject variables. Participants were more attracted to tasks that included motive imagery than to neutral tasks, and they were more confident that they could solve the former than the latter. These effects were true particularly for tasks containing affiliation motive imagery.

Tone perception in Mandarin-speaking school age children with otitis media with effusion.

ObjectivesThe present study explored tone perception ability in school age Mandarin-speaking children with otitis media with effusion (OME) in noisy listening environments. The study investigated the interaction effects of noise, tone type, age, and hearing status on monaural tone perception, and assessed the application of a hierarchical clustering algorithm for profiling hearing impairment in children with OME.MethodsForty-one children with normal hearing and normal middle ear status and 84 children with OME with or without hearing loss participated in this study. The children with OME were further divided into two subgroups based on their severity and pattern of hearing loss using a hierarchical clustering algorithm. Monaural tone recognition was measured using a picture-identification test format incorporating six sets of monosyllabic words conveying four lexical tones under speech spectrum noise, with the signal-to-noise ratio (SNR) conditions ranging from -9 to -21 dB.ResultsLinear correlation indicated tone recognition thresholds of children with OME were significantly correlated with age and pure tone hearing thresholds at every frequency tested. Children with hearing thresholds less affected by OME performed similarly to their peers with normal hearing. Tone recognition thresholds of children with auditory status more affected by OME were significantly inferior to those of children with normal hearing or with minor hearing loss. Younger children demonstrated poorer tone recognition performance than older children with OME. A mixed design repeated-measure ANCOVA showed significant main effects of listening condition, hearing status, and tone type on tone recognition. Contrast comparisons revealed that tone recognition scores were significantly better under -12 dB SNR than under -15 dB SNR conditions and tone recognition scores were significantly worse under -18 dB SNR than those obtained under -15 dB SNR conditions. Tone 1 was the easiest tone to identify and Tone 3 was the most difficult tone to identify for all participants, when considering -12, -15, and -18 dB SNR as within-subject variables. The interaction effect between hearing status and tone type indicated that children with greater levels of OME-related hearing loss had more impaired tone perception of Tone 1 and Tone 2 compared to their peers with lesser levels of OME-related hearing loss. However, tone perception of Tone 3 and Tone 4 remained similar among all three groups. Tone 2 and Tone 3 were the most perceptually difficult tones for children with or without OME-related hearing loss in all listening conditions.ConclusionsThe hierarchical clustering algorithm demonstrated usefulness in risk stratification for tone perception deficiency in children with OME-related hearing loss. There was marked impairment in tone perception in noise for children with greater levels of OME-related hearing loss. Monaural lexical tone perception in younger children was more vulnerable to noise and OME-related hearing loss than that in older children.