Combined EEG and eye tracking in sports skills training and performance analysis

The use of mobile EEG brainwave monitoring and eye-tracking recorded synchronously during the training of sports skills offers significant opportunities but creates challenges. Opportunities: ♦ Measuring neurocognitive activity and visual focus in real time which can be used to provide immediate feedback to the coach, in ‘real world’ settings, for optimising training protocols for the individual athlete. ♦ Use of sound output (‘sonification’) in proportion to EEG regions of interest as a neurofeedback mechanism for athlete self-training. ♦ Application of visualisation protocols and ‘EEG-driven’ PC games where game feedback based on state of mind is used to optimise mental state prior to performance. ♦ Examining the relationship between eye movement and neuro activity (e.g. saccades and gamma waves) and in athlete coaching interventions such as sports visual scanning strategies, Eye Movement Desensitisation & Reprocessing (EMDR) therapy, focussed relaxation, etc. Challenges: ♦ The recording of EEG during gross motor behaviour is subject to non-brain artefacts in the raw (time-domain) EEG, due to the much larger (than EEG) electrical voltages arising from muscle and eye movements. Practical approaches and signal processing (frequency domain spectrum) techniques to address these problems will be discussed. ♦ The synchronisation of data recorded on different types of equipment (e.g. EEG, eyetracker, video, sound, EMG, etc.) with different ‘clocks’ and diverse data formats is difficult – both in terms of time-stamping the original recordings across all the systems and playing them back synchronously for subsequent performance analysis. Progress on creating real-time data export methods which allow synchronous data recording and playback will be reported. Examples of studies carried out in archery, golf, motorsport, football and skiing will be discussed, with a focus on archery where: ♦ Measurements were taken from intermediate, county level, near elite and elite archers. ♦ Archery was chosen to demonstrate the real-time and in-situ quantification of neural activity compared with target-based measures of performance that archery provides, over a range of time-spans and skills. ♦ Results demonstrate that there are significant and measurable changes in EEG patterns during a shot with evidence suggesting that the patterns vary as a function of skill level, but not simply as a function of score. Significance of each of these studies for goal-directed learning and performance enhancement are discussed

Variational Inference as Iterative Projection in a Bayesian Hilbert Space

Variational Bayesian inference is an important machine-learning tool that finds application from statistics to robotics. The goal is to find an approximate probability density function (PDF) from a chosen family that is in some sense `closest' to the full Bayesian posterior. Closeness is typically defined through the selection of an appropriate loss functional such as the Kullback-Leibler (KL) divergence. In this paper, we explore a new formulation of variational inference by exploiting the fact that the set of PDFs constitutes a Bayesian Hilbert space under careful definitions of vector addition, scalar multiplication and an inner product. We show that variational inference based on KL divergence then amounts to an iterative projection of the Bayesian posterior onto a subspace corresponding to the selected approximation family. In fact, the inner product chosen for the Bayesian Hilbert space suggests the definition of a new measure of the information contained in a PDF and in turn a new divergence is introduced. Each step in the iterative projection is equivalent to a local minimization of this divergence. We present an example Bayesian subspace based on exponentiated Hermite polynomials as well as work through the details of this general framework for the specific case of the multivariate Gaussian approximation family and show the equivalence to another Gaussian variational inference approach. We furthermore discuss the implications for systems that exhibit sparsity, which is handled naturally in Bayesian space.Comment: 28 pages, 7 figures, submitted to Annals of Mathematics and Artificial Intelligenc

Data mining of portable EEG brain wave signals for sports performance analysis: An Archery case study

BACKGROUND ♦ Achievement in high performance sport requires an appropriate ‘state of mind’, which is trained alongside the physical skills. ♦ However, quantification of mental state during coaching is often difficult. ♦ With the advent of a new generation of portable compact EEGs and wireless eye tracking devices, one can measure the neurocognitive activity of an athlete’s brain and their visual focus simultaneously in ecologically representative training scenarios. AIM/OBJECTIVES ♦ We present evidence suggesting that the ‘state of mind’ of an athlete can be measured and compared with target-based performance measures. METHOD ♦ Measurements were taken from intermediate, county level, near elite and elite archers investigating: o quantification of EEG brain wave signals comparing archers of different abilities o correlation of EEG data across shots as a function of marksmanship o prototyping real-time EEG data feedback using sound during training o synchronous EEG and eye tracking ♦ Archery was chosen to demonstrate the real-time and in-situ quantification of neural activity compared with target-based measures of performance that archery provides, over a range of timespans and skills. ♦ Mental performance was explored during stages of a shot, across shots within a set, or across different sessions. RESULTS ♦ Results demonstrate that there are significant and measurable changes in EEG patterns during a shot with evidence suggesting that the patterns vary as a function of skill level, but not simply as a function of score. ♦ Significance of each of these outcomes for goal-directed learning and performance enhancement are discussed. DISCUSSION ♦ This may provide coaches and athletes with real-time EEG feedback to identify differing mental skill execution compared to a baseline or aspirational measurement from another athlete. ♦ Future work includes injury recovery/prevention and welfare, rehabilitation, and work with mobility-challenged non-athletes

The effects of acute wild blueberry supplementation on the cognition of 7-10 year old schoolchildren

Purpose: Previous evidence suggests consumption of flavonoids, a sub-class of polyphenols, is associated with improved cognitive function across the lifespan. In particular, acute intervention of a flavonoid-rich wild blueberry (WBB) drink has been shown to boost executive function (EF), short-term memory and mood 2-6 h post-consumption in 7-10 yr old children. However, confirmation of the aspects of EF and memory susceptible to WBB ingestion is required, particularly during childhood, a critical period of neurological development. In addition, the child literature on berry-flavonoid supplementation and cognition highlights the potential for such interventions to elicit positive benefits to real world educational scenarios, such as reading; a complex ability which relies upon aspects of cognition already known to improve following WBB. Methods: Here we examined which aspects of EF and memory are susceptible to acute WBB, as well as investigating whether acute WBB could further benefit reading ability. Fifty-four healthy children, aged 7-10 yrs, consumed a 200ml WBB drink (253mg anthocyanins) or a matched placebo according to a randomised, single-blind, parallel groups design. Verbal memory (Auditory Verbal Learning Task; AVLT), EF (Modified Attention Network Task; MANT), and reading efficiency (Test of Word Reading Efficiency-2; TOWRE-2) were assessed at baseline and 2 h post consumption. Results: For the MANT, significantly quicker RTs were observed for WBB participants when compared to placebo participants on 120 ms trials, without cost to accuracy. Furthermore, WBB participants showed enhanced verbal memory performance on the AVLT, recalling more words than placebo participants on short delay and memory acquisition measures post-consumption. Despite these significant improvements in cognitive performance, no significant effects were observed for reading measures. Conclusion: Consumption of WBB was found to significantly improve memory and attentional aspects of EF. This indicates that a flavonoid-rich blueberry product, equivalent to 240 g or 1½ cups of fresh blueberries can provide acute cognitive benefits in children. These findings support accumulating evidence that flavonoid-rich products are beneficial for healthy brain function, particularly during critical developmental periods. However, the lack of findings relating to reading ability suggested acute WBB may not be sufficient to elicit benefits to reading. Chronic supplementation and other more sensitive reading measures should be considered for examining the effects of WBB on such a complex skill in the future

Changes in the total fecal bacterial population in individual horses maintained on a restricted diet over 6 weeks

Twelve mature (aged 5–16 years) horses and ponies of mixed breed and type were fed restricted (1.25% BM Dry matter) quantities of one of two fiber based diets formulated to be iso-caloric. Diet 1 comprised of 0.8% body mass (BM) of chaff based complete feed plus 0.45% BM low energy grass hay (the same hay used for both diets). Diet 2 comprised 0.1% BM of a nutrient balancer plus 1.15% BM grass hay. Fecal samples were collected at week 10 and week 16. DNA was extracted and the V1-V2 regions of 16SrDNA were 454-pyrosequenced to investigate the bacterial microbiome of the horse. The two most abundant phyla found in both diets and sampling periods were the Firmicutes and Bacteroidetes. There was a clear reduction in Bacteroidetes with a concordant increase in Firmicutes over time. There was a limited degree of stability within the bacterial community of the hindgut of horses, with 65% of bacteria retained, over a 6 week period whilst on a uniform diet. The presence of a core community defined by being present in all samples (each animal/diet combination) included in the study and being present at 0.1% relative abundance (or greater) was identified. In total 65 operational taxonomic units (OTUs) were identified that fit the definition of core making up 21–28% of the total sequences recovered. As with total population the most abundant phyla were the Bacteroidetes followed by the Firmicutes, however there was no obvious shift in phyla due to period. Indeed, when the relative abundance of OTUs was examined across diets and periods there was no significant effect of diet or period alone or in combination on the relative abundance of the core OTUs

Fault-tolerant formation driving mechanism designed for heterogeneous MAVs-UGVs groups

A fault-tolerant method for stabilization and navigation of 3D heterogeneous formations is proposed in this paper. The presented Model Predictive Control (MPC) based approach enables to deploy compact formations of closely cooperating autonomous aerial and ground robots in surveillance scenarios without the necessity of a precise external localization. Instead, the proposed method relies on a top-view visual relative localization provided by the micro aerial vehicles flying above the ground robots and on a simple yet stable visual based navigation using images from an onboard monocular camera. The MPC based schema together with a fault detection and recovery mechanism provide a robust solution applicable in complex environments with static and dynamic obstacles. The core of the proposed leader-follower based formation driving method consists in a representation of the entire 3D formation as a convex hull projected along a desired path that has to be followed by the group. Such an approach provides non-collision solution and respects requirements of the direct visibility between the team members. The uninterrupted visibility is crucial for the employed top-view localization and therefore for the stabilization of the group. The proposed formation driving method and the fault recovery mechanisms are verified by simulations and hardware experiments presented in the paper

Inulin and freeze-dried blueberry intervention lead to changes in the microbiota and metabolites within in vitro studies and in cognitive function within a small pilot trial on healthy children

The relationship between the gut microbiota and cognitive health is complex and bidirectional, being significantly impacted by our diet. Evidence indicates that polyphenols and inulin can impact cognitive function via various mechanisms, one of which is the gut microbiota. In this study, effects of a wild blueberry treatment (WBB) and enriched chicory inulin powder were investigated both in vitro and in vivo. Gut microbiota composition and metabolites, including neurotransmitters, were assessed upon faecal microbial fermentation of WBB and inulin in a gut model system. Secondly, microbiota changes and cognitive function were assessed in children within a small pilot (n = 13) trial comparing WBB, inulin, and a maltodextrin placebo, via a series of tests measuring executive function and memory function, with faecal sampling at baseline, 4 weeks post-intervention and after a 4 week washout period. Both WBB and inulin led to microbial changes and increases in levels of short chain fatty acids in vitro. In vivo significant improvements in executive function and memory were observed following inulin and WBB consumption as compared to placebo. Cognitive benefits were accompanied by significant increases in Faecalibacterium prausnitzii in the inulin group, while in the WBB group, Bacteroidetes significantly increased and Firmicutes significantly decreased (p < 0.05). As such, WBB and inulin both impact the microbiota and may impact cognitive function via different gut-related or other mechanisms. This study highlights the important influence of diet on cognitive function that could, in part, be mediated by the gut microbiota