The impact of the left inferior frontal gyrus on fear extinction: A transcranial direct current stimulation study.

INTRODUCTION: Fear extinction is a fundamental component of exposure-based therapies for anxiety-related disorders. The renewal of fear in a different context after extinction highlights the importance of contextual factors. In this study, we aimed to investigate the causal role of the left inferior frontal gyrus (LiFG) in the context-dependency of fear extinction learning via administration of transcranial direct current stimulation (tDCS) over this area. METHODS: 180 healthy subjects were assigned to 9 groups: 3 tDCS conditions (anodal, cathodal, and sham) × 3 context combinations (AAA, ABA, and ABB). The fear conditioning/extinction task was conducted over three consecutive days: acquisition, extinction learning, and extinction recall. tDCS (2 mA, 10min) was administered during the extinction learning phase over the LiFG via a 4-electrode montage. Skin conductance response (SCR) data and self-report assessments were collected. RESULTS: During the extinction learning phase, groups with excitability-enhancing anodal tDCS showed a significantly higher fear response to the threat cues compared to cathodal and sham stimulation conditions, irrespective of contextual factors. This effect was stable until the extinction recall phase. Additionally, excitability-reducing cathodal tDCS caused a significant decrease of the response difference between the threat and safety cues during the extinction recall phase. The self-report assessments showed no significant differences between the conditions throughout the experiment. CONCLUSION: Independent of the context, excitability enhancement of the LiFG did impair fear extinction, and led to preservation of fear memory. In contrast, excitability reduction of this area enhanced fear extinction retention. These findings imply that the LiFG plays a role in the fear extinction network, which seems to be however context-independent.

Application of transcranial alternating current stimulation to improve eSports-related cognitive performance.

Introduction: Electronic Sports (eSports) is a popular and still emerging sport. Multiplayer Online Battle Arena (MOBA) and First/Third Person Shooting Games (FPS/TPS) require excellent visual attention abilities. Visual attention involves specific frontal and parietal areas, and is associated with alpha coherence. Transcranial alternating current stimulation (tACS) is a principally suitable tool to improve cognitive functions by modulation of regional oscillatory cortical networks that alters regional and larger network connectivity. Methods: In this single-blinded crossover study, 27 healthy college students were recruited and exposed to 10 Hz tACS of the right frontoparietal network. Subjects conducted a Visual Spatial Attention Distraction task in three phases: T0 (pre-stimulation), T1 (during stimulation), T2 (after-stimulation), and an eSports performance task which contained three games ("Exact Aiming," "Flick Aiming," "Press Reaction") before and after stimulation. Results: The results showed performance improvements in the "Exact Aiming" task and hint for a prevention of reaction time performance decline in the "Press Reaction" task in the real, as compared to the sham stimulation group. We also found a significant decrease of reaction time in the visual spatial attention distraction task at T1 compared to T0 in the real, but not sham intervention group. However, accuracy and inverse efficiency scores (IES) did not differ between intervention groups in this task. Discussion: These results suggest that 10 Hz tACS over the right frontal and parietal cortex might improve eSports-related skill performance in specific tasks, and also improve visual attention in healthy students during stimulation. This tACS protocol is a potential tool to modulate neurocognitive performance involving tracking targets, and might be a foundation for the development of a new concept to enhance eSports performance. This will require however proof in real life scenarios, as well optimization.

The ultrastructural and morphological characteristics of the anterior cruciate ligament of the pig: a study using 7.0-Tesla diffusion tensor imaging.

OBJECTIVE: Diffusion tensor imaging research on the anterior cruciate ligament (ACL) is limited, and no study has revealed the ACL fibrous microstructure by 7.0-Tesla magnetic resonance imaging. Therefore, we used magnetic resonance imaging to assess the ACL. METHODS: Eight porcine ACLs were investigated by diffusion tensor imaging. Imaging was performed with a 7.0-Tesla scanner using a diffusion-weighted two-dimensional spin-echo echo-planar imaging pulse sequence optimised for muscle. The diffusion tensor eigenparameters, fractional anisotropy (FA), and apparent diffusion coefficient (ADC) were used for bones and muscles. Three-dimensional projection maps of the principal eigenvectors were plotted to visualise the microstructure. RESULTS: The mean FA and ADC for the ACL were 0.27 ± 0.079 and 0.0012 ± 0.0005, respectively. There were no significant differences between the values in the proximal and distal portions . However, the ADC was smaller in the centre than on the sides (0.0015 ± 0.0007), and the mean FA was larger in the centre than on the sides (0.42 ± 0.23). The ACL fibres were parallel on the proximal and distal sides but interweaved in the centre. CONCLUSIONS: These findings may be beneficial for artificial ligaments.

Effect of Transcranial Direct Current Stimulation on Endurance Performance in Elite Female Rowers: A Pilot, Single-Blinded Study.

Endurance, which is dependent at least partly upon the activation of the brain cortex, is important for performance in rowing. Transcranial direct current stimulation (tDCS) has shown benefits for endurance, but its effects on the endurance performance of elite rowing athletes are unknown, and are examined in this study. Eight elite female rowers completed 5 km of rowing on an ergometer following stimulation of the tDCS and sham over motor cortices. Each session lasted 20 min and the current was set at 2.2 mA. Time, 500 m/split, power, time corresponding to 500 m (TC500) and power corresponding to 500 m (PC500) were recorded continuously throughout the tests. No significant differences in time, 500 m/split and power were observed between baseline, tDCS and sham. Compared to the sham, tDCS induced a percentage reduction in TC500 from baseline to 2500 m and 4000 m, and a percentage increase in PC500 from baseline to 500 m, 1000 m, 1500 m, 2000 m, 2500 m, 4000 m, 4500 m and 5000 m. One-session tDCS did not have significant benefits for rowing endurance performance in elite professional rowers, and had only marginally greater efficacy compared to sham. These findings offer knowledge helpful to the design of future studies exploring the effects of tDCS on the endurance performance of elite rowers.

A possible prediction of dystocia at the time of cesarean delivery: Gluteal muscle contracture, a single center experience from China.

The study assessed the pelvic dimensions by computed tomography (CT) performed for gluteal muscle contracture women, and evaluated the impact of malformations on several essential obstetric parameters.The CT pelvimetry was retrospectively performed in 25 gluteal muscle contracture women selected consecutively whether they had delivery history or not. Among the pelvic inlet plane, the mid plane and the outlet plane, 12 indicators including the transverse diameter of the pelvic inlet, the conjugate vera, the diagonal conjugate, the biischial diameter, the anteroposterior diameter of the middle pelvis, transverse outlet, the posterior sagittal diameter of outlet, the conjugate of the outlet, the anterior sagittal diameter of the outlet, the curvature and length of the sacrum, the angle of pubic arch were collected.Finally, the mean age of these women was 26.6 ±â€Š5.0 years. Most pelvises had anteroposterior elliptical appearance in inlet and size of the female pelvis. The most statistically different and most clinically significant indicator was the biischial diameter, gluteal muscle contracture women were 95.6 ±â€Š9.3 mm and the normal women from other study were 105.0 ±â€Š7.9 mm, the comparison showed a significant difference (P < .001).Generally, most gluteal muscle contracture women had features of anthropoid pelvis which were quite different from normal Chinese female. These results may serve as a basis for future studies to assess its utility and prognostic value for a safe vaginal delivery in gluteal muscle contracture women.