Effects of Multiple Sessions of Cathodal Priming and Anodal HD-tDCS on Visuo Motor Task Plateau Learning and Retention

A single session of priming cathodal transcranial direct current stimulation (tDCS) prior to anodal tDCS (c-a-tDCS) allows cumulative effects on motor learning and retention. However, the impact of multiple sessions of c-a-tDCS priming on learning and retention remains unclear. Here, we tested whether multiple sessions of c-a-tDCS (over 3 consecutive days) applied over the left sensorimotor cortex can further enhance motor learning and retention of an already learned visuo-motor task as compared to anodal tDCS (a-tDCS) or sham. In a between group and randomized double-blind sham-controlled study design, 25 participants separated in 3 independent groups underwent 2 days of baseline training without tDCS followed by 3-days of training with both online and offline tDCS, and two retention tests (1 and 14 days later). Each training block consisted of five trials of a 60 s circular-tracing task intersected by 60 s rest, and performance was assessed in terms of speed–accuracy trade-off represented notably by an index of performance (IP). The main findings of this exploratory study were that multiple sessions of c-a-tDCS significantly further enhanced IP above baseline training levels over the 3 training days that were maintained over the 2 retention days, but these learning and retention performance changes were not significantly different from the sham group. Subtle differences in the changes in speed–accuracy trade-off (components of IP) between c-a-tDCS (maintenance of accuracy over increasing speed) and a-tDCS (increasing speed over maintenance of accuracy) provide preliminary insights to a mechanistic modulation of motor performance with priming and polarity of tDCS.

Prediction of NOx Emissions for a Range of Engine Hardware Configurations Using Artificial Neural Networks

The predictive ability of artificial neural networks where a large number of experimental data are available, has been studied extensively. Studies have shown that ANN models are capable of accurately predicting NOx emissions from engines under various operating conditions and different fuel types when trained well. One of the major advantages of an ANN model is its ability to relearn when new experimental data is available, thus continuously improving its accuracy. The present work explored the potential of an ANN model to predict NOx emissions for various engine configurations outside its training envelop. This work also looked into quantifying the amount of new data required to improve the accuracy of the model when exposed to unknown conditions. The chosen ANN model was constructed using data from a high-speed direct injection diesel engine and is capable of accurate NOx emissions over a wide range of operating conditions. The optimized network utilized 14 input parameters and is using 6 neurons in a single hidden layer feed-forward neural network. Experimental data from the various engine configurations tested, were then used to predict NOx from the existing ANN model. The results indicate that when the new data are within the baseline training envelop, the ANN model is capable of accurate NOx prediction even when there are substantial changes in engine configuration such as piston material. Similar results were also observed when the injector nozzle is changed. However, the model’s performance drops significantly when new data, outside the baseline training envelop, were employed indicating that additional training is required. As such, various methods for retraining the ANN model were explored with the selected method showing the best compromise between new-data accuracy and old-data accuracy retention. The retrained ANN model developed was found to be an effective tool in predicting NOx emissions for different engine configurations and operating conditions.

Attention Networks in ADHD Adults after Working Memory Training with a Dual n-Back Task

Patients affected by Attention-Deficit/Hyperactivity Disorder (ADHD) are characterized by impaired executive functioning and/or attention deficits. Our study aim is to determine whether the outcomes measured by the Attention Network Task (ANT), i.e., the reaction times (RTs) to specific target and cue conditions and alerting, orienting, and conflict (or executive control) effects are affected by cognitive training with a Dual n-back task. We considered three groups of young adult participants: ADHD patients without medication (ADHD), ADHD with medication (MADHD), and age/education-matched controls. Working memory training consisted of a daily practice of 20 blocks of Dual n-back task (approximately 30 min per day) for 20 days within one month. Participants of each group were randomly assigned into two subgroups, the first one with an adaptive mode of difficulty (adaptive training), while the second was blocked at the level 1 during the whole training phase (1-back task, baseline training). Alerting and orienting effects were not modified by working memory training. The dimensional analysis showed that after baseline training, the lesser the severity of the hyperactive-impulsive symptoms, the larger the improvement of reaction times on trials with high executive control/conflict demand (i.e., what is called Conflict Effect), irrespective of the participants’ group. In the categorical analysis, we observed the improvement in such Conflict Effect after the adaptive training in adult ADHD patients irrespective of their medication, but not in controls. The ex-Gaussian analysis of RT and RT variability showed that the improvement in the Conflict Effect correlated with a decrease in the proportion of extreme slow responses. The Dual n-back task in the adaptive mode offers as a promising candidate for a cognitive remediation of adult ADHD patients without pharmaceutical medication.

Knowledge acquisition and retention after a high flow training programme in Peru: a quasi-experimental single group pre–post design

ObjectiveRespiratory infections remain the leading infectious cause of death in children under 5 and disproportionately affect children in resource-limited settings. Implementing non-invasive respiratory support can reduce respiratory-related mortality. However, maintaining competency after deployment can be difficult. Our objective was to evaluate the effectiveness of a comprehensive multidisciplinary high-flow training programme in a Peruvian paediatric intensive care unit (PICU).DesignQuasi-experimental single group pre–post intervention study design.SettingQuaternary care PICU in a resource-constrained setting in Lima, Peru.ParticipantsAttending physicians, fellows, paediatric residents, registered nurses, respiratory therapists and medical technicians working in the PICU were invited to participate.InterventionsConcurrent with initial high-flow deployment, we implemented a training programme consisting of lectures, case-based discussion and demonstrations with baseline, 3-month and 12-month training sessions. Pre-training and post-training assessment surveys were distributed surrounding all training sessions.Primary and secondary outcome measuresThe primary outcome was achieving minimum competency (median score of 80%) on the high flow training assessment tool. Secondary outcomes included knowledge acquisition (differences in pre-baseline and post-baseline training assessments), short-term retention (differences in post-baseline and pre-3-month refresher training assessments) and long-term retention (differences in post-3-month refresher and pre-12-month refresher training assessments).ResultsEighty participants (50% nurses, 15% ICU physicians and 34% other providers) completed the baseline assessment. Participants showed improvement in overall score and all subtopics except the clinical application of knowledge after baseline training (p<0.001). Participants failed to retain minimum competency at 3-month and 12-month follow-up assessments (70% (IQR: 57–74) and 70% (IQR: 65–74), respectively). After repeat training sessions, overall knowledge continued to improve, exceeding baseline performance (78% (IQR: 70–87), 83% (IQR: 74–87) and 87% (IQR: 83–91) at baseline, 3 and 12 months, respectively).ConclusionThis study suggests the need for repeat training sessions to achieve and maintain competency after the implementation of new technology.

The Role of Training for Dental Students in Scoring Caries

Introduction: Training of dental students is an essential part of the teaching- learning activities in order to obtain reliable results in scoring of dental caries. The objectives of this study are to examine consistency in scoring of caries over a 3-month period following baseline training, calibration and retraining. Methods: Three examiners (dental students) received baseline training/calibration by a "gold standard" examiner (lecturer). This was followed by a re-calibration and retraining 3 months later. A set of 20 extracted teeth was used for the baseline training and for the re-calibration purposes. The International Caries Detection and Assessment System (ICDAS) was used to classify the visual caries lesion severity (0-6 scale) of surface of permanent teeth. The examination utilized a clinical light, dental mirror, dental probe and air syringe. Kappa (unweighted: Kappa) statistics were used to determine inter-examiner reliability at baseline and re-calibration. Results: For caries score criteria, the baseline calibration on 20 specimens indicated an inter-rater kappa ranging from 0.37-0.69. Re-calibration on the same 20 specimens 3 months later indicated an inter-rater kappa of 0.79-0.89. Activity kappa was in the poor to good range. All examiners improved with time. Conclusions: Training contributes to the consistency and reliability of dental caries scoring among dental students.

Development of oddity concept learning in children: an evidence of intra-modal transfer

We investigated the formation of oddity concept in human subjects by means of multiple oddity discrimination tasks. Four human subjects were concurrently trained to discriminate an odd object from three identical objects in a row where the former one was reinforced. Discrimination tasks were gradually increased (e.g. 12 oddity tasks, 30 oddity tasks). Two out of four human subjects rapidly learned the acquisition tasks with higher accuracy rate suggesting that they seemed to avoid responding based on the strategy of the item-specific learning and to adopt relational processing. This assumption was stronger when robust transfer of learning with higher accuracy in baseline training performances was showed by them in transfer test 1 and transfer test 2. Although these findings offer evidence of relational oddity learning in humans, the possibility of the effect of stimulus generalization and the sense of perceptual oddity could not be excluded.