Local and large-scale beta oscillatory dysfunction in males with mild traumatic brain injury.

Mild traumatic brain injury (mTBI) is impossible to detect with standard neuroradiological assessment such as structural magnetic resonance imaging (MRI). Injury does, however, disrupt the dynamic repertoire of neural activity indexed by neural oscillations. In particular, beta oscillations are reliable predictors of cognitive, perceptual, and motor system functioning, as well as correlating highly with underlying myelin architecture and brain connectivity-all factors particularly susceptible to dysregulation after mTBI. We measured local and large-scale neural circuit function by magnetoencephalography (MEG) with a data-driven model fit approach using the fitting oscillations and one-over f algorithm in a group of young adult men with mTBI and a matched healthy control group. We quantified band-limited regional power and functional connectivity between brain regions. We found reduced regional power and deficits in functional connectivity across brain areas, which pointed to the well-characterized thalamocortical dysconnectivity associated with mTBI. Furthermore, our results suggested that beta functional connectivity data reached the best mTBI classification performance compared with regional power and symptom severity [measured with Sport Concussion Assessment Tool 2 (SCAT2)]. The present study reveals the relevance of beta oscillations as a window into neurophysiological dysfunction in mTBI and also highlights the reliability of neural synchrony biomarkers in disorder classification.NEW & NOTEWORTHY Mild traumatic brain injury (mTBI) disrupts the dynamic repertoire of neural oscillations, but so far beta activity has not been studied. In mTBI, we found reductions in frontal beta and large-scale beta networks, indicative of thalamocortical dysconnectivity and disrupted information flow through cortico-basal ganglia-thalamic circuits. Relatively, connectivity more accurately classifies individual mTBI cases compared with regional power. We show the relevance of beta oscillations in mTBI and the reliability of these markers in classification.

The effects of visual distractors on cognitive load in a motor imagery brain-computer interface.

A brain-computer interface (BCI) is a system that translates neural activity into a practical output. Its functionality, therefore, depends not only on the computer itself, but also on the cognitive system of the user. Distractors have the potential to capture attention, increase cognitive load, and may therefore impact BCI use. The purpose of the current study is to determine the effects of small visual distractors on the cognitive load of users of a motor imagery-BCI, and to examine whether these distractor-mediated effects can be improved by modifying the task interface. Sixteen typically-developed participants completed two sessions of online motor imagery to control an EEG-BCI, under conditions of no distractors, visual distractors, and cognitive strategies (intended to mitigate cognitive load) amid distractors. Cognitive load for each session was assessed through both a ratio of theta to alpha power and the NASA-Task Load Index (NASA-TLX). Task-irrelevant visual stimuli were found to significantly increase the objective measure of cognitive load, particularly for parietal channels. Subjective cognitive load as indexed by the NASA-TLX was predictive of a decrease in BCI performance for participants with below 0.75 classification accuracy (R2 = 0.32, p < 0.001), which may indicate a differential susceptibility to changes in workload for "low"-performing participants. Quantifying and addressing the increased cognitive load imparted by distractors on BCI users can aid in the future applicability of the technology in real-world settings.

Exclusive Breastfeeding Duration and its Effect on the Health of the Children in Iran, a Meta Analysis.

PROBLEM: Given the importance of exclusive breastfeeding (EB) duration on growth and to maintain health in children, we decided to systematically review the existing research on EB duration and its effect on the health of 2- to 5-year-old children in Iran. ELIGIBILITY CRITERIA: A systematic literature search was conducted in the Database of Abstracts of Reviews of Effects (DARE), Google Scholar, PubMed, Psyc INFO, Thomson Reuters, Cochrane, and Medical Library (MedLib) to detect appropriate studies (1994 to 2016). Outcomes of mean, mean difference, and proportions were pooled. SAMPLE: In this meta-analysis, 38 studies met the eligibility criteria. RESULTS: The pooled mean of EB was calculated as 4.1 months (CI 95%: 3.2, 4.99). The meta prevalence of EB up to 4 months and 5 to 6 months was estimated 65.0% (CI 95%: 54.0, 77.0) and 54% (CI 95%: 46.0, 62.0) respectively. Based on studies conducted over the years from 1994 to 2016, an increasing trend of EB was found in infants up to 4 months (p ≤ 0.0001). Among children with anemia and respiratory diseases EB until 5 to 6 months was more common than in healthy children (CI 95%; 1.1, 2.11, and 1.01, 1.47 respectively). CONCLUSION: The duration of EB (4.1 months) was equal to the lower limit recommended by the World Health Organization (WHO). Overall, the duration of EB until 5 to 6 months is sufficient if the child's iron intake is well-monitored. IMPLICATION: Monitoring of the implementation of recent guidelines or even modification of the duration period of the iron administration is potentially necessary.

Investigating the effects of visual distractors on the performance of a motor imagery brain-computer interface.

OBJECTIVES: Brain-computer interfaces (BCIs) allow users to operate a device or application by means of cognitive activity. This technology will ultimately be used in real-world environments which include the presence of distractors. The purpose of the study was to determine the effect of visual distractors on BCI performance. METHODS: Sixteen able-bodied participants underwent neurofeedback training to achieve motor imagery-guided BCI control in an online paradigm using electroencephalography (EEG) to measure neural signals. Participants then completed two sessions of the motor imagery EEG-BCI protocol in the presence of infrequent, small visual distractors. BCI performance was determined based on classification accuracy. RESULTS: The presence of distractors was found to affect motor imagery-specific patterns in mu and beta power. However, the distractors did not significantly affect the BCI classification accuracy; across participants, the mean classification accuracy was 81.5 ±â€¯14% for non-distractor trials, and 78.3 ±â€¯17% for distractor trials. CONCLUSION: This minimal consequence suggests that the BCI was robust to distractor effects, despite motor imagery-related brain activity being attenuated amid distractors. SIGNIFICANCE: A BCI system that mitigates distraction-related effects may improve the ease of its use and ultimately facilitate the effective translation of the technology from the lab to the home.