Significant Between-condition Differences Research Articles

The effect of self-reflection on information usage and information literacy in a digital serious game

In crisis management decision-making, decision-makers have to combine (limited) situational information with their own experience. Whereas traditional, analog training of decision-making situations in crisis management costs considerable time and effort, digital serious games can be used as more accessible training environments to offer additional training moments. Another advantage is that digital games offer new didactic opportunities, such as inducing specific reflection from the trainees. This study examines the effect of self-reflection through social comparison on information usage and information literacy of players of a digital serious game for crisis management decision-making training. In an experiment, data was collected from 73 participants, 47 were eligible for further analysis, split over two conditions. Participants played two gameplay scenarios in fixed order. Participants in the experimental condition, between the two scenarios, saw a dashboard displaying their own as well as previous players’ in-game behavior up to that point. Participants in the control condition received no intervention between playing the two scenarios. Overall, participants in the experimental condition used significantly more information from more different sources, and compared to the control condition they kept taking significantly more time to decide in the second scenario. No significant between-condition differences regarding information literacy were found. Results indicate that in-game behavior can be (positively) influenced by letting players self-reflect on their own in-game behavior through social comparison. Results also suggest that the dashboard should display more specific information of players’ in-game behavior, providing guidance on what to improve, rather than simply offering a broad overview.

Breaking up sitting with short frequent or long infrequent physical activity breaks does not lead to compensatory changes in appetite, appetite-regulating hormones or energy intake

The aim of this study was to determine the appetite-related responses to breaking up prolonged sitting with physical activity bouts differing in frequency and duration among adult females. Fourteen sedentary females aged 34 ± 13 years with a body mass index of 27.1 ± 6.3 kg/m2 (mean ± SD) took part in a randomised crossover trial with three, 7.5 h conditions: (1) uninterrupted sitting (SIT), (2) sitting with short frequent 2-min moderate-intensity walking breaks every 30 min (SHORT-BREAKS), and (3) sitting with longer duration, less frequent 10-min moderate-intensity walking breaks every 170–180 min (LONG-BREAKS). The intensity and total duration of physical activity was matched between the SHORT-BREAKS and LONG-BREAKS conditions. Linear mixed models were used to compare the outcomes between conditions with significance being accepted as p ≤ 0.05. There were no significant between-condition differences in hunger, satisfaction, prospective food consumption or overall appetite area under the curve (AUC) (all p ≥ 0.801). Absolute ad libitum energy intake and relative energy intake (REI) did not differ significantly between conditions (all p ≥ 0.420). Acylated ghrelin and total peptide YY incremental and total AUC did not differ significantly between conditions (all p ≥ 0.388). Yet, there was a medium effect size for the higher acylated ghrelin incremental AUC in SHORT-BREAKS versus SIT (d = 0.61); the reverse was seen for total AUC, which was lower in SHORT-BREAKS versus SIT (d = 0.69). These findings suggest that breaking up sitting does not lead to compensatory changes in appetite, appetite hormones or energy intake regardless of physical activity bout duration and frequency among adult females.

Examining the influence of adolescent:provider alliance on youth hazardous drinking: Findings from a randomized controlled trial

PurposeBehavioral interventions to reduce hazardous drinking are only moderately successful in promoting sustained behavior change and post-intervention effect sizes among adolescents remain modest. This study aimed to explore a relevant therapeutic active ingredient, adolescent:provider alliance, as a moderator of short-term (3 month) adolescent intervention outcomes within the course of a larger parent randomized control trial (RCT). MethodsParticipants were community-based youth engaged in hazardous drinking (N = 168) who were randomized to 2 sessions of either motivational interviewing (MI) or mindfulness (brief adolescent mindfulness; BAM). Youth reported pre-intervention hazardous drinking at baseline and rated therapeutic alliance (a metric of adolescent:provider “connectedness” that helps facilitate working relationships during interventions) immediately post-intervention; they reported hazardous drinking again at 3 months post-intervention. Negative binomial regressions predicted post-intervention hazardous drinking score from adolescent:provider alliance, intervention condition, and their interaction. ResultsMean hazardous drinking was reduced by 34–40 % across both intervention conditions, with no significant between-condition differences. Stronger adolescent:provider alliance was associated with lower hazardous drinking scores at 3 months, but this effect was attenuated after controlling for baseline hazardous drinking. Contrary to predictions, adolescent:provider alliance did not appear to moderate the effect of intervention condition in this sample of young people engaged in hazardous drinking. ConclusionsConsistent with prior literature, baseline hazardous drinking was a robust predictor of treatment outcomes. At the same time, these results suggest that future work may benefit from continuing to examine and disaggregate the nature of adolescent:provider alliance across the spectrum of empirically supported brief interventions for adolescent hazardous drinking.Clinical Trials Registration Number: ClinicalTrials.gov identifier: NCT03367858.Data Sharing Statement: Requests for deidentified individual participant data can be made to the first author.

The effect of validation and invalidation on positive and negative affective experiences

ABSTRACT Validation communicates that another’s experiences make sense and are understood, while invalidation dismisses the validity of an individual’s experience. Validation has the potential to preserve positive affect in the face of interpersonal stressors. We aimed to assess and replicate the effect of validation/invalidation on changes in affective experiences. We conducted three experimental studies in which participants were randomized to have their experiences of anger either validated or invalidated. We examined the effects of condition on changes in positive and negative affect as well as global mood. Participants in the validation conditions reported lower decreases in positive affect and mood over the course of the experiment compared to participants in the invalidation conditions. We did not find significant between-condition differences on negative affect. These studies highlight the importance of validation as a communication strategy to buffer against decreases in positive affective experiences after a stressor.

Effects of personalised motor imagery on the development of a complex weightlifting movement

ABSTRACT While recent research has indicated that personalised motor imagery (MI) interventions are beneficial to skill performance, little research has investigated the influence of personalised MI on performance of complex weightlifting movements. In addition, this research has rarely compared the efficacy of personalised scripts with instructor-generated scripts and has focused mainly on performance outcomes as opposed to examining the performance processes. A total of 16 individuals novice in the power clean were randomly allocated to one of two conditions: personalised MI, or instructor-generated MI. Participants engaged in a 6-week training intervention, completing three power clean sessions per week. Scripts were listened to five times each week. Results indicated no significant between-condition differences for total forward displacement at 1RM and 90% 1RM (both p = 0.27), but there was a significant difference at 80% of 1RM for total forward displacement between conditions (p = 0.04, g = −0.94). Differences between conditions for rearward displacement were not significant at any intensities (p = 0.54). No significant (p = 0.16–0.97) between-condition differences in kinetic variables were detected at any intensity over the 6-week training period. Findings indicate that the differences in script content do not influence the development of complex weightlifting movements. A large degree of variation was evident when observing the SD’s of technical variables for each group which may have contributed to the present results. Future research should seek analysis techniques that allows for further investigation of movement variability and how this impacts the efficacy of personalised MI.

Home Use of Remote Microphone Systems by Children with Hearing Loss

Home Use of Remote Microphone Systems by Children with Hearing Loss

Effect of blood flow occlusion on neuromuscular fatigue following sustained maximal isometric contraction.

Sustained isometric maximal voluntary contractions (IMVCs) have blood flow occlusive effects on the microvasculature. However, it is unknown if this effect would be magnified with additional blood flow restriction via a cuff and what the influence on fatigue development would be. Twelve healthy male participants performed a 1-min IMVC of the knee extensors with and without additional blood flow occlusion induced by pneumatic cuff in counterbalanced order on separate days. Vastus lateralis muscle deoxygenation was estimated via near-infrared spectroscopy-derived tissue oxygen saturation (SmO2) throughout the fatiguing contraction. Central and peripheral measures of neuromuscular fatigue (NMF) were assessed via surface electromyography (EMG) and force responses to voluntary contractions and peripheral nerve/transcranial magnetic stimulations before, immediately after, and throughout an 8-min recovery period. SmO2, force, and EMG amplitude decreased during the 1-min IMVC, but there were no between-condition differences. Similarly, no significant (p > 0.05) between-condition differences were detected for any dependent variable immediately after the fatiguing contraction. Transcranial magnetic stimulation (TMS)-derived voluntary activation was lower (p < 0.05) in the no-cuff condition during the recovery period. Sustained IMVC results in a similar degree of muscle deoxygenation and NMF as IMVCs with additional occlusion, providing further evidence that a sustained IMVC induces full ischemia. Novelty NMF etiology, muscle oxygenation, and corticospinal factors during an IMVC are similar with or without an occlusion cuff. Contrary to all other measures, TMS-evaluated voluntary activation returned to baseline faster following the occluded condition.

Manipulating Initial Peak vGRF During Walking Affects Loading Throughout Stance in Individuals with ACL Reconstruction

Gait alterations may be associated with osteoarthritis development following anterior cruciate ligament reconstruction (ACLR). Novel gait retraining paradigms are being developed to optimize peak vertical limb loading in the first half of stance; yet the effect of changing this single discrete variable on loading characteristics across the entire stance phase remain unknown. PURPOSE: Determine the effect of increasing and decreasing the first peak of the vertical ground reaction force (vGRF) by 5% during walking using real-time biofeedback (RTBF) of vGRF throughout stance. METHODS: 30 ACLR participants (21 females, 20.4±2.9 yrs, 172.7±10.8 cm, 73.2±16.1 kg, 47.8±4.2 months post-ACLR) completed one 20-minute control condition and two experimental conditions (high- and low-loading). For high- and low-load conditions, participants walked for 20 minutes on a force-measuring treadmill with RTBF displayed on a screen cuing a 5% increase (high) or decrease (low) in the first peak of the vGRF relative to vGRF collected in the control condition. VGRFs were collected at 1000 Hz throughout the 19th minute. Two functional analyses of variance were conducted to evaluate VGRF magnitude throughout stance. RESULTS: Figures 1A and 1C depict mean vGRF, normalized to body weight (BW), throughout the stance phase. Figures 1B and 1D depict pairwise comparison functions (solid black lines) and associated 95% confidence intervals (gray bands), indicating mean differences between the two conditions. Significant between-condition differences existed in the high-loading condition between 42 and 74% of stance, and in the low-loading condition (between 38 and 70%, and 76 and 97% of stance. CONCLUSION: RTBF, used to cue changes in the first vGRF peak, results in loading alterations throughout stance. Specifically, high loading results in lesser vGRF at midstance but a similar propulsive peak. Conversely, low loading increases vGRF during midstance and decreases vGRF during toe-off.

One-Year Follow-Up of a Randomized Controlled Trial Piloting a Mindfulness-Based Group Intervention for Adolescent Insulin Resistance.

IntroductionTo explore if a brief mindfulness-based intervention (MBI) leads to sustained, improved clinical outcomes in adolescents at-risk for type 2 diabetes (T2D).MethodsParticipants were 12–17y girls with overweight/obesity, elevated depression symptoms, and T2D family history participating in a randomized, controlled pilot trial of a six-session MBI vs. cognitive-behavioral therapy (CBT) group. At baseline and 1-year, mindfulness, depression, insulin resistance (IR), and body composition were assessed with validated instruments.ResultsOne-year retention was 71% (n = 12) in MBI; 81% (n = 13) in CBT. At 1-year, depression decreased (Cohen’s d = 0.68) and IR decreased (d = 0.73) in adolescents randomized to MBI compared to those in CBT. There were no significant between-condition differences in mindfulness, adiposity, or BMI.DiscussionOne-year outcomes from this randomized, controlled pilot trial suggest that brief MBI may reduce depression and IR in at-risk adolescents. Replication and exploration of mechanisms within the context of a larger clinical trial are necessary.Clinical Trial Registrationwww.ClinicalTrials.gov, identifier NCT02218138.

Acute Kinematic Effects of Sprinting With Motorized Assistance.

Clark, K, Cahill, M, Korfist, C, and Whitacre, T. Acute kinematic effects of sprinting with motorized assistance. J Strength Cond Res 35(7): 1856-1864, 2021-Although assisted sprinting has become popular for training maximum velocity, the acute effects are not fully understood. To examine this modality, 14 developmental male sprinters (age: 18.0 ± 2.5 years, 100-m personal best: 10.80 ± 0.31 seconds) performed maximal trials, both unassisted and assisted with a motorized towing device using a load of 7 kg (9.9 ± 0.9% body mass). Significant increases in maximum velocity (+9.4%, p ≤ 0.001, d = 3.28) occurred due to very large increases in stride length (+8.7%, p ≤ 0.001, d = 2.04) but not stride rate (+0.7%, p = 0.36, d = 0.11). Stride length increased due to small changes in distance traveled by the center of mass during ground contact (+3.7%, p ≤ 0.001, d = 0.40) combined with very large changes in distance traveled by the center of mass during flight (+13.1%, p ≤ 0.001, d = 2.62). Although stride rate did not demonstrate significant between-condition differences, the combination of contact and flight time was different. Compared to unassisted sprinting, assisted sprinting caused small but significant decreases in contact time (-5.2%, p ≤ 0.001, d = 0.49) and small but significant increases in flight time (+3.4%, p < 0.05, d = 0.58). Sprinting with motorized assistance elicited supramaximal velocities with decreased contact times, which may represent a neuromuscular stimulus for athletes attempting to enhance sprinting performance. Future research is needed to investigate the effects of this modality across various assistive loads and athletic populations, and to determine the longitudinal efficacy as a training method for improving maximum-velocity sprinting performance.

The Heat Is On: Effects of Synchronous Music on Psychophysiological Parameters and Running Performance in Hot and Humid Conditions

Running in high heat and humidity increases psychophysiological strain, which typically impairs running performance. Listening to synchronous music has been shown to provide psychophysiological benefits, which may enhance running performance. The present randomized, crossover study examined effects of listening to synchronous music on psychophysiological parameters and running performance in hot and humid conditions. Twelve male runners (21.7 ± 2.2 y; 166.17 ± 7.18 cm; 60.32 ± 9.52 kg; 59.29 ± 5.95 ml kg−1 min−1) completed two running trials in simulated conditions (31°C and 70% humidity) with and without synchronous music. Participants ran on a treadmill inside a climatic chamber for 60 min at 60% O2max and continued to run to exhaustion at 80% O2max. Time-to-exhaustion under the synchronous music condition was 66.59% longer (mean = 376.5 s vs. 226.0 s, p = 0.02, d = 0.63) compared to the no music condition. Ratings of perceived exertion were significantly lower for the synchronous music condition at each time point (15, 30, 45, and 60 min) of the steady state portion of the running trials. Small differences in heart rate were detected between conditions. No significant between-condition differences were found in urine specific gravity, percentage of body weight loss, thermal comfort, and blood lactate. Findings suggest that listening to synchronous music is beneficial to running performance and perceived exertion in hot and humid conditions.

The effects of rational and irrational coach team talks on the cognitive appraisal and achievement goal orientation of varsity football athletes

The effects of rational and irrational coach team talks on cognitive appraisal and achievement goal orientation were examined. During the half-time interval of a 60 min football match, 25 male varsity football athletes ( Mage = 20.20; SD ± 1.38 years) received a rational ( n = 13) or an irrational ( n = 12) team talk from a coach. Irrational and rational beliefs were measured before the football match. Task engagement, cognitive appraisal (challenge and threat), and achievement goal orientation (approach and avoidance) regarding second-half football performance were measured following team talk delivery. Athletes in the rational team talk condition reported significantly lower threat appraisal and avoidance goal orientation than athletes in the irrational team talk condition. No significant between-condition differences emerged for challenge appraisal and approach goal orientation. For coaching practice, data suggest that communicating rational or irrational beliefs to football athletes through a half-time team talk will influence appraisal and achievement goal orientation regarding upcoming performance.

Pilot Randomized Controlled Trial of LEAP: A Selective Preventive Intervention to Reduce Adolescents’ Perceived Burdensomeness

This research draws upon the interpersonal-psychological theory of suicide in the development of the LEAP intervention, a web-based selective preventive suicide intervention targeting cognitions of perceived burdensomeness toward others. The pilot randomized controlled trial consisted of 80 adolescents (68.8% female, 65.8% Hispanic) 13–19 of age years who were randomly assigned to either the LEAP intervention or a psychoeducational control condition. Participants completed baseline, posttreatment, and 6-week follow-up assessments. All participants reported high levels of satisfaction with the program. Findings on outcome variables differed across intent-to-treat analyses and treatment completer analyses. Intent-to-treat analysis yielded no significant between-condition differences in perceived burdensomeness at posttreatment or follow-up. Treatment completer analyses revealed significant between-condition differences on outcome variables such that participants who completed the LEAP intervention showed significantly lower perceived burdensomeness scores at postintervention and significantly lower perceived burdensomeness, thwarted belongingness, and depressive symptom scores at follow-up as compared to participants in the control condition. No significant differences in suicidal ideation were found between conditions. These findings support the promise of the LEAP intervention as a brief, web-based selective preventive intervention for reducing perceived burdensomeness among adolescents who complete the intervention. This study provides evidence that perceived burdensomeness can be modified via a psychosocial intervention. Future research is needed to identify ways to enhance adolescent engagement with and completion of the intervention.

3A.01

Objective: A blood pressure (BP) rise and sleep disturbances are known effects of high altitude exposure. Most available data have been collected at altitudes >3300m, while the possible effects of moderate altitude (MA) exposure (around 2000 m) are still poorly understood in spite of the fact that such altitude is easily reachable even by subjects suffering from cardiovascular diseases. Aim of HIGHCARE (HIGH altitude CArdiovascular REsearch)-Sestriere study was thus to evaluate the effect of exposure to an altitude of 2035m (Sestriere, Italy) on BP and sleep disturbances.Design and method: 58 healthy lowlanders were evaluated both at sea level (SL,Milan, Italy) and during acute exposure to MA (2035m, barometric pressure 80% of that at SL). 46 individuals (18 male, 28 females, age 41.52 ± 12.65y) completed the study, having conventional BP measures and 24 h ambulatory BP monitoring (ABPM, validated oscillometric TM-2430 A&D device; measurements every 15 minutes during daytime and 20 minutes during nighttime) performed both at SL and at MA. During both study conditions subjects’ daily life behaviour was carefully standardized, only light physical exercise being allowed. Results: During MA exposure mean 24 h systolic (S) and diastolic (D) BP significantly increased compared to SL (p < 0.005), with no difference between day and night (Figure1). This was the case also for mean daytime and nighttime SBP and DBP (respectively, p < 0.05) and for heart rate (p < 0.005) (Figure1). No statistically significant between-condition differences were found for conventional BP nor for nocturnal BP dipping, and there were no effects of age, gender or BMI. Low sleep quality was reported by 22% of individuals (sleep quality questionnaire), with no correlation between reported sleep quality and BP nocturnal dipping. Conclusions: Our data offer the first demonstration, in healthy subjects, that exposure to an easy-to-reach MA is associated with an increase in 24 h ambulatory BP. No changes were observed in conventional BP, further emphasizing the superior sensitivity of ABPM in assessing BP response to environmental challenges. Our results may have clinical implications for the protection of cardiovascular patients travelling to such altitude for either leisure or work.

A study of the immediate effects of glycerine-filled insoles, contoured prefabricated orthoses and flat insoles on single-leg balance, gait patterns and perceived comfort in healthy adults.

BackgroundFootwear interventions are often prescribed to assist with the management of lower limb pain, injury and disease. Commercially available shoe insoles and orthoses are increasingly incorporating novel design features to alleviate foot and lower limb symptoms, but this may be at a cost to optimal functional performance. This study compared the immediate effects of wearing glycerine-filled insoles, contoured prefabricated orthoses, and flat insoles, on balance and gait measures.MethodsThirty healthy adults (17 men, 13 women; mean [SD] age: 24.3 [2.5] years) performed tests of single-leg standing with eyes open (Kistler force platform), star excursion balance test, and level-ground walking (GAITRite® walkway system), under three randomised conditions: wearing glycerine-filled insoles, prefabricated orthoses, and flat (control) insoles, within their own footwear. Centre of pressure movement (anterior-posterior and mediolateral range and standard deviation, total path velocity), star excursion balance test reach distance, and temporospatial gait variables were collected. Perceived comfort of the inserts was scored immediately after use on a 100 mm visual analogue rating scale. After trialling all inserts each participant ranked their level of comfort from least to most.ResultsCentre of pressure measures, star excursion balance test reach distance, or temporospatial gait variables did not differ between the three inserts (all P values >0.088). Significant between-condition differences were reported for comfort ranking (P = 0.031), but not rating scores (P = 0.638). Weak to moderate negative correlations (r values ranged between −0.368 and −0.406) were observed between visual analogue scale comfort rating for the flat insoles and prefabricated orthoses, star excursion balance test and gait measures.ConclusionsSingle-leg standing balance, star excursion balance test performance, and level-ground walking patterns in asymptomatic adults do not appear to differ when wearing glycerine-filled insoles, contoured prefabricated orthoses, or flat insoles. Perceived comfort may be related to the biomechanical or clinical effectiveness of novel footwear interventions, and requires further investigation. Importantly, these findings are specific to a healthy population and further research is needed to determine the long-term effects of glycerine-filled insoles in patients with known balance impairments.

Breaking up prolonged sitting reduces resting blood pressure in overweight/obese adults

AimTo compare the effect of 7 h of prolonged sitting on resting blood pressure with a similar duration of sitting combined with intermittent brief bouts of light-intensity or moderate-intensity physical activity. Methods and resultsOverweight/obese adults (n = 19; aged 45–65 years) were recruited for a randomized three-treatment crossover trial with a one-week washout between treatments: 1) uninterrupted sitting; 2) sitting with 2 min bouts of light-intensity walking at 3.2 km/h every 20 min; and, 3) sitting with 2 min bouts of moderate-intensity walking at between 5.8 and 6.4 km/h every 20 min. After an initial 2 h period seated, participants consumed a test meal (75 g carbohydrate, 50 g fat) and completed each condition over the next 5 h. Resting blood pressure was assessed oscillometrically every hour as a single measurement, 5 min prior to each activity bout. GEE models were adjusted for sex, age, BMI, fasting blood pressure and treatment order.After adjustment for potential confounding variables, breaking up prolonged sitting with light and moderate-intensity activity breaks was associated with lower systolic blood pressure [light: 120 ± 1 mmHg (estimated marginal mean ± SEM), P = 0.002; moderate: 121 ± 1 mmHg, P = 0.02], compared to uninterrupted sitting (123 ± 1 mmHg). Diastolic blood pressure was also significantly lower during both of the activity conditions (light: 76 ± 1 mmHg, P = 0.006; moderate: 77 ± 1 mmHg, P = 0.03) compared to uninterrupted sitting (79 ± 1 mmHg). No significant between-condition differences were observed in mean arterial pressure or heart rate. ConclusionRegularly breaking up prolonged sitting may reduce systolic and diastolic blood pressure. Trial registration numberACTRN12609000656235 (http://www.anzctr.org.au) Trial registration dateAugust 4th 2009.

The good and the bad one: Gait-patterns in twins with cerebral palsy

Tripping over obstacles is a common cause of falls in older adults, and muscle fatigue, which can alter walking patterns, may add to this risk. To date, no study has examined the effect of lower limb muscle fatigue on obstacle negotiation in older adults. 30 older adults (13 women, aged 78.3 [6.2] years) negotiated a 12 m obstacle course, while completing a visual secondary task, under two randomized conditions: rested or fatigued. For the fatigue condition, participants performed a repeated sit-to-stand movement, as fast as possible, until they could no longer continue. Participants then immediately began walking trials. Kinematic and kinetic data were collected on approach to, during, and after crossing a height-adjustable target obstacle (10% and 20% of leg length). Repeated measures ANOVA showed a statistically significant increase in lead limb vertical loading rate after stepping over the 10% obstacle when fatigued, relative to rested (P = 0.046). No other significant between-condition differences (>0.05) were observed for the other kinematic variables when negotiating the 10% obstacle. Furthermore, no significant between-condition differences (P > 0.05) were observed for any kinetic or kinematic variables when negotiating the 20% obstacle. This study describes a feasible method for investigating the consequences of lower limb muscle fatigue on obstacle crossing. The current finding of increased vertical loading rate when fatigued supports the need for further investigation into the effect of muscle fatigue on gait under different environmental conditions, fatiguing a range of muscles, analyzing a more comprehensive array of kinetic and kinematic measures, and in healthy and clinical populations.

The effect of resting condition on resting-state fMRI reliability and consistency: A comparison between resting with eyes open, closed, and fixated

Resting-state fMRI (rs-fMRI) has been demonstrated to have moderate to high reliability and produces consistent patterns of connectivity across a wide variety of subjects, sites, and scanners. However, there is no one agreed upon method to acquire rs-fMRI data. Some sites instruct their subjects, or patients, to lie still with their eyes closed, while other sites instruct their subjects to keep their eyes open or even fixating on a cross during scanning. Several studies have compared those three resting conditions based on connectivity strength. In our study, we assess differences in metrics of test-retest reliability (using an intraclass correlation coefficient), and consistency of the rank-order of connections within a subject and the ranks of subjects for a particular connection from one session to another (using Kendall's W tests). Twenty-five healthy subjects were scanned at three different time points for each resting condition, twice the same day and another time two to three months later. Resting-state functional connectivity measures were evaluated in motor, visual, auditory, attention, and default-mode networks, and compared between the different resting conditions. Of the networks examined, only the auditory network resulted in significantly higher connectivity in the eyes closed condition compared to the other two conditions. No significant between-condition differences in connectivity strength were found in default mode, attention, visual, and motor networks. Overall, the differences in reliability and consistency between different resting conditions were relatively small in effect size but results were found to be significant. Across all within-network connections, and within default-mode, attention, and auditory networks statistically significant greater reliability was found when the subjects were lying with their eyes fixated on a cross. In contrast, primary visual network connectivity was most reliable when subjects had their eyes open (and not fixating on a cross).

Effects of Computer-Mediated Versus Teacher-Mediated Instruction on the Mathematical Word Problem-Solving Performance of Third-Grade Students With Mathematical Difficulties

This study compared the effectiveness of computer-mediated instruction (CMI) and teacher-mediated instruction (TMI) on the word problem-solving performance of students struggling in mathematics. Both conditions integrated cognitive modeling that focused on the problem structure using visual representations with critical instructional elements specifically targeting the needs of at-risk students. Participants were 25 third-grade students with mathematics difficulties who were randomly assigned to either a TMI or a CMI condition. Results indicated no statistically significant between-condition differences at posttest and on a 4-week retention test of word problem-solving. Furthermore, there was no transfer of the word problem-solving skills to a school administered, standardized mathematics achievement test. Implications for educational practice are discussed.

The effect of lower limb muscle fatigue on obstacle negotiation during walking in older adults

Tripping over obstacles is a common cause of falls in older adults, and muscle fatigue, which can alter walking patterns, may add to this risk. To date, no study has examined the effect of lower limb muscle fatigue on obstacle negotiation in older adults. 30 older adults (13 women, aged 78.3 [6.2] years) negotiated a 12m obstacle course, while completing a visual secondary task, under two randomized conditions: rested or fatigued. For the fatigue condition, participants performed a repeated sit-to-stand movement, as fast as possible, until they could no longer continue. Participants then immediately began walking trials. Kinematic and kinetic data were collected on approach to, during, and after crossing a height-adjustable target obstacle (10% and 20% of leg length). Repeated measures ANOVA showed a statistically significant increase in lead limb vertical loading rate after stepping over the 10% obstacle when fatigued, relative to rested (P=0.046). No other significant between-condition differences (>0.05) were observed for the other kinematic variables when negotiating the 10% obstacle. Furthermore, no significant between-condition differences (P>0.05) were observed for any kinetic or kinematic variables when negotiating the 20% obstacle. This study describes a feasible method for investigating the consequences of lower limb muscle fatigue on obstacle crossing. The current finding of increased vertical loading rate when fatigued supports the need for further investigation into the effect of muscle fatigue on gait under different environmental conditions, fatiguing a range of muscles, analyzing a more comprehensive array of kinetic and kinematic measures, and in healthy and clinical populations.