The effects of left and right monocular viewing on hemispheric activation

Hemispheric synchronization patterns linked with shooting performance in archers

Sustainable attention, effective visual-spatial perception, and motor control skills are considered highly important for achieving superior athletic performance. The aim of the current study was to investigate hemispheric synchronization patterns of brain electrical activation related to successful and unsuccessful shots of archers using electroencephalography (EEG). This study involved 16 elite archers, each shooting 36 arrows. The 10 shots closest to the target's center were successful, while the 10 farthest shots were unsuccessful. The transformed EEG data, obtained through surface Laplacian filtering, were divided into 5 sub-bands (theta, alpha1, alpha2, beta1, beta2) by calculating the alpha peak frequencies. The synchronization values of the electrode pairs were calculated using the Phase Locking Value (PLV) method. To compare the EEG data for successful and unsuccessful shots in all frequency bands, the linear mixed models were fitted. Perceived fatigue levels were quantified using a visual analog scale (VAS). Spearman's correlation analysis was conducted to examine the relationship between fatigue and shooting performance. The results showed significantly higher coupling strength for C3-O1, C4-O2, O1-O2, F3-F4, C4-T8, T7-O2, F4-C4, C3-O2 and F4-T8 pairs during successful shooting. Moreover, the coupling strengths for F3-O2, F4-T7, C3-C4, C3-T8, T7-T8, C4-O1, F3-T8, and F4-O2 were significantly higher in unsuccessful shooting. The current findings revealed differences in the synchronization patterns associated with shooting performance. It is observed that visual-motor performance is correlated with an increase in cortical synchronization values during successful shots. These findings have the potential to serve as a theoretical reference that contributes to superior performance.

Associations of macular microvascular parameters with cerebral small vessel disease in rural older adults: A population-based OCT angiography study

Objective

To explore the associations of macular microvascular parameters with cerebral small vessel disease (CSVD) in rural-dwelling older adults in China.

Methods

This population-based cross-sectional study included 195 participants (age ≥ 60 years; 57.4% women) in the optical coherence tomographic angiography (OCTA) sub-study within the Multimodal Interventions to delay Dementia and disability in rural China (MIND-China). Macular microvascular parameters were measured using the OCTA. We automatically estimated volumes of gray matter, white matter, and white matter hyperintensity (WMH), and manually assessed numbers of enlarged perivascular spaces (EPVS) and lacunes on brain magnetic resonance imaging. Data were analyzed with the general linear models.

Results

Adjusting for multiple confounders, lower vessel skeleton density (VSD) and higher vessel diameter index (VDI) were significantly associated with larger WMH volume (P < 0.05). Lower VSD and foveal density-300 (FD-300) of left eye were significantly associated with lower brain parenchymal volume (P < 0.05). In addition, lower areas of foveal avascular zone (FAZ) and FD-300 of left eye were significantly associated with more EPVS (P < 0.05). The associations of abnormal macular microvascular parameters with WMH volume were evident mainly among females. Macular microvascular parameters were not associated with lacunes.

Conclusion

Macular microvascular signs are associated with WMH, brain parenchymal volume, and EPVS in older adults. The OCTA-assessed macular microvascular parameters can be valuable markers for microvascular lesions in the brain.

Vertical pseudoneglect: Sensory-attentional versus action-intentional

INTRODUCTION

Healthy persons demonstrate an upward bias on the vertical-line bisection test (vertical or "altitudinal" pseudoneglect). This bias might be sensory-attentional or action-intentional in origin. To test the action-intention hypothesis, we analyze whether the direction of action has an effect on altitudinal pseudoneglect.

METHODS

Twenty-four healthy right-handed adults performed vertical-line bisection on an apparatus designed to distinguish the effects of sensory-attention and action-intention. Depending on hand placement, participants estimated line midpoints with a marker that moved in the same (congruent) or opposite (incongruent) direction as their hand movements. Two binary factors - hand movement in the upward versus downward direction and congruent vs incongruent hand movements - produced four conditions.

RESULTS

There was upward deviation from the midline across all conditions. Bisections in the incongruent condition were higher than in the congruent condition. Bisections were also higher with upward hand movements than with downward hand movements. There was not a significant interaction between these factors.

CONCLUSIONS

These results suggest that vertical pseudoneglect is primarily influenced by the allocation of allocentric attention, rather than action-intention. However, action-perceptual spatial incongruence increased this deviation. Perhaps the incongruent condition requires greater allocation of attention, but further exploration is needed. Additionally, these results suggest that visual attention follows the direction of motor action. Future studies of visual attention should consider the potential influence of this factor.

Hemispheric stroke: Mood disorders

Stroke causes many forms of disability, including emotional and mood disorders. Depression is the most common of these, affecting approximately one-third of stroke patients. Other disorders like mania, bipolar disorder, anxiety disorder, or apathy may also develop following stroke, although they are less common. The development of mood and emotional disorders is dependent on the severity of brain injury, the side of injury, and hemispheric location. Whereas a left hemispheric stroke often results in depression or a catastrophic reaction with anxiety, injury to the right hemisphere has predominantly been associated with the development of emotional indifference (anosodiaphoria) or euphoria. In this chapter, we discuss the mood disorders associated with hemispheric strokes and the neuropsychological mechanisms that might account for the clinical manifestations of these affective disorders.