Walking impairs cognitive performance among people with multiple sclerosis but not controls

People with multiple sclerosis (MS) complain of problems completing two tasks simultaneously; sometimes called ‘dual-tasking’ (DT). Previous research in DT among people with MS has focused on how adding a cognitive task interferes with gait and few have measured how adding a motor task could interfere with cognition. We aimed to determine the extent to which walking affects a concurrent working memory task in people with MS compared to healthy controls. We recruited MS participants (n = 13) and controls (n = 10) matched by age (±3 years), education (±3 years) and gender. Participants first completed the cognitive task (subtracting 7’s from the previous number) and then again while walking on an instrumented walkway. Although there were no baseline differences in cognition or walking between MS participants and controls, MS participants demonstrated a 52% decrease in number of correct answers during DT (p < 0.001). Mental Tracking Rate (% correct answers/min) correlated strongly with MS-related disability measured using the Expanded Disability Status Scale (EDSS; r(11) = −0.68, p < 0.01). We propose that compromised mental tracking during walking could be related to limited neural resource capacity and could be a potentially useful outcome measure to detect ecologically valid dual tasking impairments.     

Propulsion strategy in the gait of primary school children; the effect of age and speed

The strategy used to generate power for forward propulsion in walking and running has recently been highlighted as a marker of gait maturation and elastic energy recycling. This study investigated ankle and hip power generation as a propulsion strategy (PS) during the late stance/early swing phases of walking and running in typically developing (TD) children (15: six to nine years; 17: nine to 13 years) using three-dimensional gait analysis. Peak ankle power generation at push-off (peakA2), peak hip power generation in early swing (peakH3) and propulsion strategy (PS) [peakA2/(peakA2 + peakH3)] were calculated to provide the relative contribution of ankle power to total propulsion. Mean PS values decreased as speed increased for comfortable walking (p < 0.001), fast walking (p < 0.001) and fast running (p < 0.001), and less consistently during jogging (p = 0.054). PS varied with age (p < 0.001) only during fast walking. At any speed of fast walking, older children generated more peakA2 (p = 0.001) and less peakH3 (p = 0.001) than younger children. While the kinetics of running propulsion appear to be developed by age six years, the skills of fast walking appeared to require additional neuromuscular maturity. These findings support the concept that running is a skill that matures early for TD children.     

Functioning of peripheral Ia pathways in leg muscles of newly walking toddlers

Monosynaptic and polysynaptic spinal level reflexes in the leg muscles of infants show significant dispersion across muscles, high variability, and no change in response patterns over the first 10 months. Here we tested the hypothesized relation between early walking experience and the tuning of these responses in three primary gait muscles of participants in four subgroups: cruisers (n = 7) and toddlers with one (n = 5), two (n = 5), or three (n = 5) months of walking experience. Reflex responses in multiple Ia pathways – tendon reflex (T-reflex), vibration-induced inhibition of the T-reflex (VIM-T-reflex), and tonic vibration-induced reflex (VIR), were elicited by mechanical stimuli applied to the distal tendons of the quadriceps, gastrocnemius-soleus, and tibialis anterior of both legs. Walking skill was assessed via a GAITRite mat. Generally, walking experience seemed to be related to slowly emerging improvements and, depending on muscle tested and pathway, progress was quite varied. Amplitude and latency of reflex responses were more clearly impacted by age or leg length while the ratio or distribution pattern of reflex response among antagonist pairs of muscles was impacted by walking experience and skill. As walking experience increased, the ratio of reflex responses tended to increase for the stimulated and decrease for the antagonist reflex loops with distribution of the pattern shifting gradually toward a single type of reflex response in all tested muscles. The very slow tuning of these reflexes may underlie the many missteps and falls reported to occur during early walking and suggest that subsequent studies should continue to follow the developmental trajectory through the first year of walking experience.     

Falling for smartphones: A smartphone-centric data collection tool for measuring distracted walking

Falls and severe head injuries have been increasingly associated with the use of smartphones while walking. A growing body of academic research identifies cognitive, perceptual, and motor deficits caused by smartphone use while walking. Despite the dangers associated with smartphone use while walking, the true prevalence can be challenging to assess. To better address the growing injury risk related to smartphone-induced distraction, we have built a smartphone-based data collection tool to assess smartphone use frequency while walking. In the current study, 35 participants installed the data collection app on their Android smartphones. On average, the application collected 520 data points per day. The application also indicated participants walked 12% of their day, and 49% of their time walking included smartphone use. The current study demonstrates the prevalence of smartphone-induced distraction while walking and smartphone applications' potential efficacy to collect behavioral data.     

Personality self-concept affects processing of trait adjectives in the self-reference memory paradigm

We combined personality, social cognitive, and cognitive paradigms for researching the self. Specifically, we examined whether personality trait assessments are associated with variation in the cognitive processes that produce the self-reference effect in memory. We found that self-reported, but not indirectly assessed, trait orderliness (Study 1; N = 98) and openness (Study 2; N = 92) were associated with slower free recall when corresponding trait adjectives were self-referenced, but not when adjectives were encoded in control tasks. The slower recall showed mixed predictive validity. Results suggest that personality congruent adjectives elicit more elaborative processing in the form of propositions that arise during self-reference, which counter-intuitively slows recall in a manner consistent with random search memory models and cue overload theory.     

Head flexion and different walking speeds do not affect gait stability in older females

Head flexion is destabilizing in older individuals during quiet stance, yet the effect head flexion has on gait is not known. The study examined whether head flexion and gait parameters were altered when walking freely and fixed to a visual target, at different walking speeds. 15 young (23 ± 4 years) and 16 older (76 ± 6 years) healthy females walked at three different walking speeds (slow, comfortable, and fast) under two visual conditions (natural and fixed [focusing on a visual target set at eye level]). Head flexion was assessed using 2D video analysis, whilst gait parameters (step length, double support time, step time, and gait stability ratio) were recorded during a 9 m flat walkway. A mixed design ANOVA was performed for each variable, with age as the between-subject factor and, visual condition and walking speed as within-subject factors. When walking freely, older displayed a greater need for head flexion between walking speeds (P < 0.05) when compared to young. Walking under fixed condition reduced head flexion at all walking speeds in the older (P < 0.05), but had no effect on the young (P > 0.05). Walking at different speeds showed no difference in head flexion when walking under either visual condition and had no effect on gait stability for both groups. Despite older displaying differences in head flexion between visual conditions, there was no effect on gait parameters. Walking speed presented trivial difference in head flexion in older females, whilst overall gait stability was unaffected by different walking speeds.     

Partial body weight support treadmill training speed influences paretic and non-paretic leg muscle activation,stride characteristics,and ratings of perceived exertion during acute stroke rehabilitation

BackgroundIntensive task-specific training is promoted as one approach for facilitating neural plastic brain changes and associated motor behavior gains following neurologic injury. Partial body weight support treadmill training (PBWSTT), is one task-specific approach frequently used to improve walking during the acute period of stroke recovery (<1 month post infarct). However, only limited data have been published regarding the relationship between training parameters and physiologic demands during this early recovery phase.ObjectiveTo examine the impact of four walking speeds on stride characteristics, lower extremity muscle demands (both paretic and non-paretic), Borg ratings of perceived exertion (RPE), and blood pressure.DesignA prospective, repeated measures design was used.MethodsTen inpatients post unilateral stroke participated. Following three familiarization sessions, participants engaged in PBWSTT at four predetermined speeds (0.5, 1.0, 1.5 and 2.0 mph) while bilateral electromyographic and stride characteristic data were recorded. RPE was evaluated immediately following each trial.ResultsStride length, cadence, and paretic single limb support increased with faster walking speeds (p ⩽ 0.001), while non-paretic single limb support remained nearly constant. Faster walking resulted in greater peak and mean muscle activation in the paretic medial hamstrings, vastus lateralis and medial gastrocnemius, and non-paretic medial gastrocnemius (p ⩽ 0.001). RPE also was greatest at the fastest compared to two slowest speeds (p < 0.05).ConclusionsDuring the acute phase of stroke recovery, PBWSTT at the fastest speed (2.0 mph) promoted practice of a more optimal gait pattern with greater intensity of effort as evidenced by the longer stride length, increased between-limb symmetry, greater muscle activation, and higher RPE compared to training at the slowest speeds.     

Comparison of the trunk-pelvis and lower extremities sagittal plane inter-segmental coordination and variability during walking in persons with and without chronic low back pain

Inter-segmental coordination can be influenced by chronic low back pain (CLBP). The sagittal plane lower extremities inter-segmental coordination pattern and variability, in conjunction with the pelvis and trunk, were assessed in subjects with and without non-specific CLBP during free-speed walking. Kinematic data were collected from 10 non-specific CLBP and 10 non-CLBP control volunteers while the subjects were walking at their preferred speed. Sagittal plane time-normalized segmental angles and velocities were used to calculate continuous relative phase for each data point. Mean absolute relative phase (MARP) and deviation phase (DP) were derived to quantify the trunk-pelvis and bilateral pelvis-thigh, thigh-shank and shank-foot coordination pattern and variability over the stance and swing phases of gait. Mann-Whitney U test was employed to compare the means of DP and MARP values between two groups (same side comparison). Statistical analysis revealed more in-phase/less variable trunk-pelvis coordination in the CLBP group (P < 0.05). CLBP group demonstrated less variable right or left pelvis-thigh coordination pattern (P < 0.05). Moreover, the left thigh-shank and left shank-foot MARP values in the CLBP group, were more in-phase than left MARP values in the non-CLBP control group during the swing phase (P < 0.05). In conclusion, the sagittal plane lower extremities, pelvis and trunk coordination pattern and variability could be generally affected by CLBP during walking. These changes can be possible compensatory strategies of the motor control system which can be considered in the CLBP subjects.     

A study of reaching actions in walking infants

Acquiring motor skills transforms the perceptual and cognitive world of infants and expands their exploratory engagement with objects. This study investigated how reaching is integrated with walking among infant walkers (n = 23, 14.5–15.5 months). In a walk-to-reach paradigm, diverse object retrieval strategies were observed. All infants were willing to use their upper and lower bodies in concert, and the timing of this coordination reflected features of their environment. Infants with an older walking age (months since walking onset) retrieved items more rapidly and exploited their non-reaching hand more effectively during object retrieval than did same-age infants with a younger walking age. This suggests that the actions of the upper- and lower-body are flexibly integrated and that this integration may change across development. Mechanisms that shape sophisticated upper-body use during upright object retrieval are discussed. Infants flexibly integrate emerging motor skills in the service of object retrieval in ways not previously documented.     

An interfering dot-probe task facilitates the detection of mock crime memory in a reaction time (RT)-based concealed information test

The present study aimed to test the hypothesis that an interfering task in the concealed information test will help the detection of concealed memory based on participants' behavioral performance (e.g. reaction time, error rate). Here, after participants enacted a mock crime, they were introduced to a concealed information test either with or without an interfering dot-probe task. Results showed that the RT-based pure-CIT (without interference) can detect concealed memory well above chance (AUC = .88). The detection efficiency was higher (AUC = .94) in the interference-CIT based on participants' performance of the interfering task. The findings suggested that the elevation of cognitive workload could possibly increase the detection efficiency of concealed memory based on behavioral measures.     

Evaluation of cognitive behavior among deaf subjects with video game as intervention

Previous research on video gaming mainly focused on negative impact on users. In this study, the positive impact of action video gaming among congenitally deaf subjects is investigated. Subjects possessed high level of visual information processing capacity. A 96 h of action video game play resulted in the improvement of mean reaction time (mRT) (post = 413.21 ms, pre = 453.39 ms) and certain cognitive functions. Higher heart rate variability (HRV) subjects demonstrated faster and significant improvement in mRT (p < 0.0045) after intervention. The α and β EEG band powers were found increased in parietal (6.33%, 4.28%) and occipital (8.38%, 38%) lobes respectively. The θ band power increased in frontal (32%) and parietal (13%) lobes. These results can reflect enhancement in certain cognitive performances such as visual perception, attention, memory, and motor skills. The ratio index β/(α + θ) increased in frontal and occipital lobes while β/θ increased in frontal and temporal lobes. These results may also suggest improvements in attention processing capacity and neural activity. These results implies improvements in certain aspects of cognition among deaf subjects. However, to validate these results a further study on larger number of samples with advanced computerized cognitive battery testing can be employed.     

Effect of an intensified training period on well-being indices,recovery and psychological aspects in professional soccer players

IntroductionIntensified training periods (IT) are associated with fatigue increase and psychological variations.ObjectiveThis investigation aimed to examine the perceived well-being, recovery quality and psychological responses during an IT.MethodsFifteen professional soccer players (mean ± SD: age: 24 ± 1 years, body mass: 71.3 ± 15.1 kg, height: 178.0 ± 6.1 cm) completed a 6-week training program consisting of 2 weeks of basic training (BT) and 4 weeks of IT. They were tested before (T1) and after (T2) the IT. Training load (TL) perception, strain and monotony were measured by the session-RPE method. Well-being indices (sleep quality, fatigue level, stress and delayed-onset muscular soreness [DOMS]) and total quality recovery (TQR) were recorded before each training session. The profile of mood states (POMS) and the Ottowa mental skills assessment tool (OMSAT)-3 were conducted before and after IT.ResultsNo significant difference was found after IT in OMSAT-3 scores (p > 0.05). TL, monotony and strain increased during IT (p < 0.001). Moreover, well-being indices (stress, sleep quality, fatigue level and DOMS) increased (p < 0.001) and TQR decreased (p < 0.001) during IT. The IT increased total mood disturbance (TMD, p < 0.001), tension (p < 0.05) and fatigue (p < 0.01) and decreased vigor (p < 0.001). Significant relationships were found between TL and Hooper Index (HI), TQR and TMD (r = 0.58, 0.65, −0.57, respectively; all p < 0.05).ConclusionThe findings of this investigation suggested that mental ability was not sensitive to fatigue caused by training load intensification. However, perceived well-being, recovery state and mood were found to be sensitive measures and may provide coaches with information about wellness and psychological state of soccer players during IT.     

Two tests of the social cognitive model of well-being in Portuguese college students

A social cognitive model of well-being (Lent & Brown, 2006, 2008) was tested in two studies (one cross-sectional, one longitudinal) with Portuguese college students. Participants in Study 1 (N = 366) completed measures of academic self-efficacy, environmental support, goal progress, academic satisfaction and stress, trait positive affect, and overall life satisfaction at a single assessment. Those in Study 2 (N = 158) took the same measures at each of two time points, 15 weeks apart. A modified version of the model improved the fit to the data in Study 1. Optimal fit in Study 2 was achieved with a bidirectional version that modeled reciprocal relations of positive affect to both self-efficacy and support. The predictors in both studies accounted for substantial portions of the variance in academic domain satisfaction, academic stress, and life satisfaction. Implications for future research on the social cognitive model in educational and work settings are considered.     

Cognitive Load Undermines Thought Suppression in Acute Stress Disorder

Thought suppression studies demonstrate that attempts to suppress can be undermined by cognitive load. We report the first instance in which this has been tested experimentally in a sample of recently traumatized individuals. Individuals with and without acute stress disorder (ASD) were recruited following recent trauma and randomized to load or no load conditions (N = 56). They monitored intrusive memories during baseline, suppression, and think anything phases. The impact of suppression and load on self-reported intrusions, attention bias (dot-probe), and memory priming (word-stem task) was assessed. The ASD load group were less able to suppress memories (d = 0.32, CI₉₅ [− 0.15, 0.83], p = .088) than the ASD no load group (d = 0.63, CI₉₅ [0.08, 1.24], p < .001). In the think anything phase, the ASD load group reported more intrusions than the ASD no load or non-ASD groups (with and without load). No consistent findings were observed in relation to attentional bias. ASD load individuals exhibited stronger priming responses for motor vehicle accident and assault words than all other groups (ds between 0.35–0.73). Working memory did not moderate any outcomes of interest. The findings indicate that cognitive load interferes with suppression and may enhance access to trauma memories and associated material. The study extends previous research by demonstrating these effects for the first time in a clinical sample of recent survivors of trauma.     

Perceiving red decreases motor performance over time: A pilot study

IntroductionColors may influence motor performance.ObjectiveThe present study aimed to compare the effects of perception of red and green environments on physical (performance and heart rate) and psychological (perceived effort, anxiety and enjoyment) parameters during cycling trials.MethodTen cyclists achieved two identical series of three randomized 7-minute trials on home trainers, during which they were continuously exposed to red, green, and gray environments. Covered distance and heart rate were recorded during each trial, after which participants answered items intended to assess perceived effort, anxiety, and enjoyment experienced during the trial.ResultsResults showed that covered distance (ps ≤ .02) and heart rate (ps ≤ .03) were lower in the red environment than in the gray and green environments. Enjoyment was higher in the green environment than in the red environment (p = .006). The colored environments did not influence perceived effort and anxiety (ps > .05).ConclusionThis study is the first to show that perceiving red is detrimental for motor performance over an extended period of time.     

Comparison of fetal and maternal heart rate measures using electrocardiographic and cardiotocographic methods

PurposeTo determine the reliability at term of: (1) two methods of measuring fetal heart rate (HR), electrocardiographic (ECG, the ‘gold standard’) and cardiotocographic (CTG) and (2) two ECG methods of measuring maternal HR variability over relatively brief periods of time (s–min).MethodsDuring 20 min of rest (N = 39) and during 2 min of auditory stimulation (mother's recorded voice, n = 19), fetal HR data were collected using an ECG (Monica AN24) and a Hewlett-Packard Model 1351A CTG. Simultaneously, maternal HR data (n = 37) were collected using the same ECG device (Monica AN24) and a second stand-alone cardiac monitor (Spacelab 514T cardiac monitor with a QRS detector).ResultsDuring 20 min of maternal rest, correlations of individual fetal CTG with ECG measures of HR at each second were moderate to high (r = .57–.97) for 77% of fetuses. Correlations of HR averaged over fetuses and over each of the 20 min were high (r = .93–.97); fetal HR averaged over 20 min varied between devices from 0.0 to 0.8 bpm. During 2 min of maternal voice presentation, correlations of fetal HR over each second were moderate to high (r = .54–.99) for 95% of fetuses and high (all rs = .99) when averaged across fetuses in 30 s or 2 min epochs. Average fetal HR between devices over the 2 min voice varied from 0.0 to 0.6 bpm. Correlations and/or % agreement between the two ECG methods of measuring maternal HR were high. Average maternal HR over 10 min showed 81% of pairs with a difference of ≤1 bpm; correlations for HR variability measures varied from r = .89 to .97.ConclusionsGood reliability was demonstrated between individual spontaneous and auditory induced fetal CTG and ECG with high correlations when HR data were averaged over fetuses or in 30–120 s epochs. High reliability of maternal HR measures was obtained using two ECG devices.     

Transdiagnostic and Transcultural: Pilot Study of Unified Protocol for Depressive and Anxiety Disorders in Japan

Unified protocol (UP) is a transdiagnostic cognitive behavior therapy for emotional disorders. It remains unknown whether UP is applicable for use in non-Western countries and for depressive disorders. We therefore examined its feasibility for a Japanese clinical population using this clinical trial design, which is multicentered, open-labeled, and single-armed (Clinical registry: UMIN000008322). The primary outcome was severity of anxiety symptoms, as assessed using Structured Interview Guide for the Hamilton Anxiety Rating Scale. Secondary outcomes were depressive symptoms, clinical global impression, functioning, quality of life, affectivity, emotion regulation, and adverse events. Of the 28 prospective participants, 17 were eligible and enrolled (depressive disorders = 9, anxiety disorders = 8). Severity of anxiety symptoms, which decreased significantly after the intervention, remained low for 3 months (Hedges’ g = 1.29, 95% CI = 0.56–2.06). Similar tendencies were observed for secondary outcome measures. No severe adverse event occurred. Two participants dropped out of the intervention. High treatment adherence and interrater reliability were confirmed. Results suggest the feasibility of UP in the Japanese context sufficient to warrant a larger clinical trial.     

Personality,intelligence and proof-reading

Two studies sought to determine personality and cognitive ability correlates of proof-reading. In both studies candidates were given 5 min to identify up to 55 errors in a 920 word, two page document. In Study 1, which tested 240 school children, fluid intelligence (as measured by the Baddeley Reasoning Test) was the highest correlate of proof-reading (r = .30). Eleven percent of the variance in total attempted scores was accounted for by intelligence, Introversion and low Conscientiousness. In the second study 70 undergraduates completed the same proof-reading test along with two intelligence tests (Baddeley Reasoning Test; Wonderlic Personnel Test) and a more robust personality measure (NEO-FFI). Proof-reading was correlated with both intelligence tests (Baddeley r = .45; Wonderlic r = .40). More of the variance was accounted for in the total attempted-score of errors than for a correct errors-detected score. When the two intelligence and five personality trait scores were regressed on to the proof-reading test score over a quarter of the variance (Adj R² = .28) was accounted for, but only the Baddeley test was a significant predictor (Beta = .39).     

Attention lapses and behavioural microsleeps during tracking,psychomotor vigilance,and dual tasks

This study examined the incidence of attention lapses and microsleeps under contrasting levels of task complexity during three tasks: PVT, 2-D tracking and a dual task combining the two. More attention lapses per participant (median 15 vs. 3; range 1–74 vs. 0–76, p = 0.001), with the greatest increase with time spent-on-task (p = 0.002), were evident on the more cognitively-demanding dual task than on the PVT. Conversely, fewer microsleeps (median 0 vs. 0; range 0–1 vs. 0–18, p = 0.022) occurred during the more complex task compared to the tracking task. An increase in microsleep rate with time spent-on-task (p = 0.035) was evident during the tracking task but not the dual task. These results indicate that the higher cognitive load, associated with an increase in task complexity, increased the likelihood of attention lapses, while a reduction in task complexity increased the likelihood of microsleeps.     

Alterations in stride-to-stride variability during walking in individuals with chronic ankle instability

The aim of this study was to evaluate stride-to-stride variability of the lower extremity during walking in individuals with and without chronic ankle instability (CAI) using a nonlinear analysis. Twenty-five participants with self-reported CAI and 27 healthy control participants volunteered for this study. Participants walked on a motor-driven treadmill for 3 min at their selected speed. Lower extremity kinematics in the sagittal and frontal planes were recorded using a passive retroreflective marker motion capture system. The temporal structure of walking variability was analyzed with sample entropy (SampEn). The CAI group produced lower SampEn values in frontal-plane ankle kinematics compared to the control group (P = .04). No significant group differences were observed for SampEn values of other kinematics (P > .05). Participants with CAI demonstrated less stride-to-stride variability of the frontal plane ankle kinematics compared to healthy controls. Decreased variability of walking patterns demonstrated by participants with CAI indicates that the presence of CAI may be associated with a less adaptable sensorimotor system to environmental changes. The altered sensorimotor function associated with CAI may be targets for clinical interventions, and it is critical to explore how interventions protocols affect sensorimotor system function.