Effect of reading on blood flow changes in the posterior cerebral artery in early blind and sighted people--A transcranial Doppler study

EFFECT OF THE PROBLEM-BASED LEARNING METHOD ON STUDENT ELECTROENCEPHALOGRAMS AND MICROCIRCULATORY BLOOD PERFUSION IN THE TEACHING OF SPORTS PHYSIOLOGY

ABSTRACT Introduction Applying the problem-based learning (PBL) method to the teaching of sports physiology. Objective This study explored the mechanism of the PBL method to improve the interest and learning effectiveness of students. Methods Twenty male students at the Physical Education College of Hubei Minzu University were randomly divided into a PBL group (10) and a traditional teaching method group (TTM). During the test, the subjects in the TTM group sat quietly listening to the experienced teacher, while the subjects in PBL group sat quietly and participated in a 20-minute group discussion under the guidance of the experienced teacher. Transcutaneous partial pressure of oxygen (TcPO2), microcirculatory blood perfusion (MBP), and alpha- and beta-band power were monitored at the beginning of and during the test. Results The mean of the PBL-group quiz score was significantly higher than that of the TTM group. In the PBL group, the alpha power of the students decreased statistically in the F3, T3, P3, and O1 channels and the beta power of the students increased statistically in the F7, F3, T3, C3, P3, and O1 as compared to the baseline values. Conclusion PBL can be an effective learning mechanism, since the students are actively engaged in the teaching of sports physiology. Level of Evidence I; Therapeutic studies - Investigating treatment results.

Effect of reading with direct or indirect light on the visually evoked flow response in the posterior cerebral artery

PURPOSE

Reading with direct light from computer monitors or tablets may cause visual fatigue and hamper reading comprehension. Our aim was to compare the blood flow response in the supplying artery of the visual cortex when reading from tablet screen or from paper. The neurovascular coupling was tested also after 15-minute reading from either monitor or paper.

METHODS

Flow velocity responses evoked by reading from paper and from monitor were measured by transcranial Doppler sonography in a random sequence in both posterior cerebral arteries (PCAs) of 20 young healthy adults. Afterward, PCA flow response evoked by reading from paper was also investigated after 15 minutes reading on the same tablet or paper, in a random order.

RESULTS

Reading from monitor with its own source of light and reading from paper with indirect light caused very similar PCA flow response. Moreover, the flow velocity increase, evoked by reading form paper did not differ after 15-minute reading from monitor or from paper.

CONCLUSIONS

Reading with direct or indirect light produces similar flow response in the occipital cortex.

Reduced Dynamic Interactions Within Intrinsic Functional Brain Networks in Early Blind Patients

Neuroimaging studies in early blind (EB) patients have shown altered connections or brain networks. However, it remains unclear how the causal relationships are disrupted within intrinsic brain networks. In our study, we used spectral dynamic causal modeling (DCM) to estimate the causal interactions using resting-state data in a group of 20 EB patients and 20 healthy controls (HC). Coupling parameters in specific regions were estimated, including the medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), and inferior parietal lobule (IPC) in the default mode network (DMN); dorsal anterior cingulate cortex (dACC) and bilateral anterior insulae (AI) in the salience network (SN), and bilateral frontal eye fields (FEF) and superior parietal lobes (SPL) within the dorsal attention network (DAN). Statistical analyses found that all endogenous connections and the connections from the mPFC to bilateral IPCs in EB patients were significantly reduced within the DMN, and the effective connectivity from the PCC and lIPC to the mPFC, and from the mPFC to the PCC were enhanced. For the SN, all significant connections in EB patients were significantly decreased, except the intrinsic right AI connections. Within the DAN, more significant effective connections were observed to be reduced between the EB and HC groups, while only the connections from the right SPL to the left SPL and the intrinsic connection in the left SPL were significantly enhanced. Furthermore, discovery of more decreased effective connections in the EB subjects suggested that the disrupted causal interactions between specific regions are responsive to the compensatory brain plasticity in early deprivation.