An expert-novice comparison of lifeguard specific vigilance performance.

INTRODUCTION: Lifeguards must maintain alertness and monitor an aquatic space across extended periods. However, lifeguard research has yet to investigate a lifeguard's ability to maintain performance over time and whether this is influenced by years of certified experience or the detection difficulty of a drowning incident. The aim of this study was to examine whether lifeguard experience, drowning duration, bather number, and time on task influences drowning detection performance. METHOD: A total of 30 participants took part in nine 60-minute lifeguard specific tasks that included 11 drowning events occurring at five-minute intervals. Each task had manipulated conditions that acted as the independent variables, including bather number and drowning duration. RESULTS: The experienced group detected a greater number of drowning events per task, compared to novice and naïve groups. Findings further highlighted that time, bather number, and drowning duration has a substantial influence on lifeguard specific drowning detection performance. PRACTICAL APPLICATIONS: It is hoped that the outcome of the study will have applied application in highlighting the critical need for lifeguard organizations to be aware of a lifeguard's capacity to sustain attention, and for researchers to explore methods for minimizing any decrement in vigilance performance.

The effect of learning to drum on behavior and brain function in autistic adolescents.

This current study aimed to investigate the impact of drum training on behavior and brain function in autistic adolescents with no prior drumming experience. Thirty-six autistic adolescents were recruited and randomly assigned to one of two groups. The drum group received individual drum tuition (two lessons per week over an 8-wk period), while the control group did not. All participants attended a testing session before and after the 8-wk period. Each session included a drumming assessment, an MRI scan, and a parent completing questionnaires relating to the participants' behavioral difficulties. Results showed that improvements in drumming performance were associated with a significant reduction in hyperactivity and inattention difficulties in drummers compared to controls. The fMRI results demonstrated increased functional connectivity in brain areas responsible for inhibitory control, action outcomes monitoring, and self-regulation. In particular, seed-to-voxel analyses revealed an increased functional connectivity in the right inferior frontal gyrus and the right dorsolateral prefrontal cortex. A multivariate pattern analysis demonstrated significant changes in the medial frontal cortex, the left and right paracingulate cortex, the subcallosal cortex, the left frontal pole, the caudate, and the left nucleus accumbens. In conclusion, this study investigates the impact of a drum-based intervention on neural and behavioral outcomes in autistic adolescents. We hope that these findings will inform further research and trials into the potential use of drum-based interventions in benefitting clinical populations with inhibition-related disorders and emotional and behavioral difficulties.

Drum training induces long-term plasticity in the cerebellum and connected cortical thickness.

It is unclear to what extent cerebellar networks show long-term plasticity and accompanied changes in cortical structures. Using drumming as a demanding multimodal motor training, we compared cerebellar lobular volume and white matter microstructure, as well as cortical thickness of 15 healthy non-musicians before and after learning to drum, and 16 age matched novice control participants. After 8 weeks of group drumming instruction, 3 ×30 minutes per week, we observed the cerebellum significantly changing its grey (volume increase of left VIIIa, relative decrease of VIIIb and vermis Crus I volume) and white matter microstructure in the inferior cerebellar peduncle. These plastic cerebellar changes were complemented by changes in cortical thickness (increase in left paracentral, right precuneus and right but not left superior frontal thickness), suggesting an interplay of cerebellar learning with cortical structures enabled through cerebellar pathways.

Rock drumming enhances motor and psychosocial skills of children with emotional and behavioral difficulties.

Objectives: Drumming may have therapeutic and learning benefits but there exists little causal evidence regarding the benefits for children with emotional and behavioral difficulties (EBD) such as Autistic Spectrum Disorder. Methods: Six EBD pupils (EBD Drum) and six peers (Peer Drum) were given 2, 30-min rock drumming lessons per week, over 5 weeks. Six matched individuals received no drumming instruction (3 = EBD Control; 3 = Peer Control). An exploratory, mixed-methods analysis was used to explore quantitative changes in skills and qualitative perspectives of the teaching staff. All pupils were tested two times (pretest and posttest) on drumming ability and Motor skills (Movement Assessment Battery for Children, version 2). Teacher's rating of social behavior (Strength and Difficulties Questionnaire; SDQ) was tested two times (pretest and retention). Results: Significant differences in total SDQ difficulties between the four groups (χ2(3) = 8.210, p = 0.042) and the hyperactivity subscale (χ2(3) = 10.641, p = 0.014) were observed. The EBD Drum group had greater reductions in total difficulties compared to the Peer Drum (p = 0.009) group and specifically greater reductions in hyperactivity compared to Peer Drum (p = 0.046) and the EBD Control (p = 0.006) group. In follow-up interviews, staff spoke positively about changes in pupil's attitudes toward learning and social confidence. Conclusions: The positive changes to social and behavioral skills reported in this pilot study are similar to those recorded for other music modalities.

Motor Learning Induces Plasticity in the Resting Brain-Drumming Up a Connection.

Neuroimaging methods have recently been used to investigate plasticity-induced changes in brain structure. However, little is known about the dynamic interactions between different brain regions after extensive coordinated motor learning such as drumming. In this article, we have compared the resting-state functional connectivity (rs-FC) in 15 novice healthy participants before and after a course of drumming (30-min drumming sessions, 3 days a week for 8 weeks) and 16 age-matched novice comparison participants. To identify brain regions showing significant FC differences before and after drumming, without a priori regions of interest, a multivariate pattern analysis was performed. Drum training was associated with an increased FC between the posterior part of bilateral superior temporal gyri (pSTG) and the rest of the brain (i.e., all other voxels). These regions were then used to perform seed-to-voxel analysis. The pSTG presented an increased FC with the premotor and motor regions, the right parietal lobe and a decreased FC with the cerebellum. Perspectives and the potential for rehabilitation treatments with exercise-based intervention to overcome impairments due to brain diseases are also discussed.

A comprehensive testing protocol for MRI neuroanatomical segmentation techniques: Evaluation of a novel lateral ventricle segmentation method.

Although a wide range of approaches have been developed to automatically assess the volume of brain regions from MRI, the reproducibility of these algorithms across different scanners and pulse sequences, their accuracy in different clinical populations and sensitivity to real changes in brain volume have not always been comprehensively examined. Firstly we present a comprehensive testing protocol which comprises 312 freely available MR images to assess the accuracy, reproducibility and sensitivity of automated brain segmentation techniques. Accuracy is assessed in infants, young adults and patients with Alzheimer's disease in comparison to gold standard measures by expert observers using a manual technique based on Cavalieri's principle. The protocol determines the reliability of segmentation between scanning sessions, different MRI pulse sequences and 1.5T and 3T field strengths and examines their sensitivity to small changes in volume using a large longitudinal dataset. Secondly we apply this testing protocol to a novel algorithm for segmenting the lateral ventricles and compare its performance to the widely used FSL FIRST and FreeSurfer methods. The testing protocol produced quantitative measures of accuracy, reliability and sensitivity of lateral ventricle volume estimates for each segmentation method. The novel algorithm showed high accuracy in all populations (intraclass correlation coefficient, ICC>0.95), good reproducibility between MRI pulse sequences (ICC>0.99) and was sensitive to age related changes in longitudinal data. FreeSurfer demonstrated high accuracy (ICC>0.95), good reproducibility (ICC>0.99) and sensitivity whilst FSL FIRST showed good accuracy in young adults and infants (ICC>0.90) and good reproducibility (ICC=0.98), but was unable to segment ventricular volume in patients with Alzheimer's disease or healthy subjects with large ventricles. Using the same computer system, the novel algorithm and FSL FIRST processed a single MRI image in less than 10min while FreeSurfer took approximately 7h. The testing protocol presented enables the accuracy, reproducibility and sensitivity of different algorithms to be compared. We also demonstrate that the novel segmentation algorithm and FreeSurfer are both effective in determining lateral ventricular volume and are well suited for multicentre and longitudinal MRI studies.

Dehydration affects brain structure and function in healthy adolescents.

It was recently observed that dehydration causes shrinkage of brain tissue and an associated increase in ventricular volume. Negative effects of dehydration on cognitive performance have been shown in some but not all studies, and it has also been reported that an increased perceived effort may be required following dehydration. However, the effects of dehydration on brain function are unknown. We investigated this question using functional magnetic resonance imaging (fMRI) in 10 healthy adolescents (mean age = 16.8, five females). Each subject completed a thermal exercise protocol and nonthermal exercise control condition in a cross-over repeated measures design. Subjects lost more weight via perspiration in the thermal exercise versus the control condition (P < 0.0001), and lateral ventricle enlargement correlated with the reduction in body mass (r = 0.77, P = 0.01). Dehydration following the thermal exercise protocol led to a significantly stronger increase in fronto-parietal blood-oxygen-level-dependent (BOLD) response during an executive function task (Tower of London) than the control condition, whereas cerebral perfusion during rest was not affected. The increase in BOLD response after dehydration was not paralleled by a change in cognitive performance, suggesting an inefficient use of brain metabolic activity following dehydration. This pattern indicates that participants exerted a higher level of neuronal activity in order to achieve the same performance level. Given the limited availability of brain metabolic resources, these findings suggest that prolonged states of reduced water intake may adversely impact executive functions such as planning and visuo-spatial processing.

Effects of acute dehydration on brain morphology in healthy humans.

Dehydration can affect brain structure which has important implications for human health. In this study, we measured regional changes in brain structure following acute dehydration. Healthy volunteers received a structural MRI scan before and after an intensive 90-min thermal-exercise dehydration protocol. We used two techniques to determine changes in brain structure: a manual point counting technique using MEASURE, and a fully automated voxelwise analysis using SIENA. After the exercise regime, participants lost (2.2% +/- 0.5%) of their body mass. Using SIENA, we detected expansion of the ventricular system with the largest change occurring in the left lateral ventricle (P = 0.001 corrected for multiple comparisons) but no change in total brain volume (P = 0.13). Using manual point counting, we could not detect any change in ventricular or brain volume, but there was a significant correlation between loss in body mass and third ventricular volume increase (r = 0.79, P = 0.03). These results show ventricular expansion occurs following acute dehydration, and suggest that automated longitudinal voxelwise analysis methods such as SIENA are more sensitive to regional changes in brain volume over time compared with a manual point counting technique.

Physiological profile of senior and junior England international amateur boxers.

Despite worldwide popularity of amateur boxing, research focussed on the physiological demands of the sport is limited. The physiological profile of Senior and Junior England international amateur boxers is presented. A gradual (8 to 21-days) and rapid (0 to 7-days) phase of body weight reduction was evident with 2.2 ± 0.3 % of the 7.0 ± 0. 8 % weight loss occurring over the final 24-hours. An increase in body weight >4% was observed following a recovery period. High urine osmolality values (> 1000 mOsm·kg(-1)) were recorded during training and competition. High post-competition blood lactate values (>13.5 mmol·l(-1)) highlighted the need for a well-developed anaerobic capacity and the importance of not entering the ring in a glycogen depleted state. The aerobic challenge of competition was demonstrated by maximum heart rate values being recorded during 'Open' sparring. Mean body fat values of 9-10% were similar to those reported for other weight classified athletes. Normal resting values were reported for hematocrit (Senior 48 ± 2 % and Junior 45 ± 2 %), haemoglobin (Senior 14.7 ± 1.0 g·dl(-1) and Junior 14.5 ± 0.8 g·dl(-1)), bilirubin (Senior 15.3 ± 6.2 µmol·l-1(-1)) and ferritin (Senior 63.3 ± 45.7 ng·ml(-1)). No symptoms associated with asthma or exercise-induced asthma was evident. A well- developed aerobic capacity was reflected in the Senior VO2max value of 63.8 ± 4.8 ml·kg(-1)·min(-1). Senior lead hand straight punching force (head 1722 ± 700 N and body 1682 ± 636 N) was lower than the straight rear hand (head 2643 ± 1273 N and body 2646 ± 1083 N), lead hook (head 2412 ± 813 N and body 2414 ± 718 N) and rear hook (head 2588 ± 1040 N and body 2555 ± 926 N). It was concluded that amateur boxing performance is dependent on the interplay between anaerobic and aerobic energy systems. Current weight making methods may lead to impaired substrate availability, leading to reduced competitive performance and an increased risk to a boxers health. Key PointsSenior England international amateur boxers decrease 6.0-8.3 % (7.0 ± 0.8 %) body weight over a 21-day pre-contest period by employing passive and active weight making methods.Urine osmolality values >1000 mOsm·kg(-1) are recorded during training and competition.Senior and Junior England international amateur boxers experience high post contest blood lactate values (Seniors 13.5 ± 2 mmol·l(-1) and Juniors 14.1 ± 2 mmol·l(-1) under the current 4 rounds x 2-minute contest format.Senior England international amateur boxers have a high relative VO2max of 63.8 ± 4.8 ml·kg(-1)·min(-1)Senior England international amateur boxers have a straight and hook punch force >2400 N, except for the straight lead hand to the head and body.