Smooth pursuit eye movements and saccadic eye movements are vital for precise vision. Therefore, tests for eye movement are important for assessing nervous or muscular diseases. However, objective measurements are not frequently performed due to the need for a polygraph system, electrodes, amplifier, and personal computer for data analysis. To address this, we developed an all-in-one eye-movement-measuring device that simultaneously presents visual stimuli, records eye positions, and examines its feasibility for evaluating eye movements. This device generates stimulus that induces eye movements and records those movements continuously. The horizontal or vertical eye movements of 16 participants were measured at various visual target speeds of 20–100 deg/s. The maximum cross-correlation coefficient (rho max) between the eye and visual target positions was used as an index of eye movement accuracy. A repeated-measures multi-way analysis of variance was performed, with the main effect being that rho max significantly decreased as the visual target speed increased. The average (±standard deviation) rho max values across all velocities were 0.995 ± 0.008 and 0.967 ± 0.062 in the horizontal and vertical directions, respectively, and were significantly higher for horizontal eye movements than for vertical eye movements. Moreover, rho max and saccadic frequency were significantly correlated for the slowest and fastest visual target motions. These suggest that our device enables accurate measurements of eye movements. We believe our new measurement device can be applied clinically for easily and objectively evaluating eye movements.

Athletes, particularly ball game players, benefit from focusing on fast-moving visual targets. In this study, we hypothesized that athletes, specifically professional basketball players, exhibit more accurate saccadic eye movements compared to non-athletes. To test this hypothesis, we assessed the eye movements of eight female professional basketball players from the Niigata Albirex BB (basketball player group) and compared them to eight sex-matched healthy volunteers from a previous study. Eye movements were measured using the Eye Score device. The visual target moved continuously for 20 s at a speed of 100 degrees/s in regular triangular wave-like movements horizontally. The subjects tracked the visual targets with maximum accuracy. The total amplitudes of evoked eye movements during tracking were 37.96 ± 0.82 for the basketball player group and 27.74 ± 2.55 deg (mean ± SEM) for the non-athlete group, indicating a significant difference. These findings suggest that basketball players may achieve accurate saccades by employing predictive saccades. The saccades of the basketball players were concentrated at the fifth frame (0.17 s after the onset of target motion), exhibiting a more peaked distribution than the normal curve. The results imply that athletes may execute predictive saccades when tracking targets with predictable movements, even outside of actual competition.

Propagation of oscillatory spike firing activity at specific frequencies plays an important role in distributed cortical networks. However, there is limited evidence for how such frequency-specific signals are induced or how the signal spectra of the propagating signals are modulated during across-layer (radial) and inter-areal (tangential) neuronal interactions. To directly evaluate the direction specificity of spectral changes in a spiking cortical network, we selectively photostimulated infragranular excitatory neurons in the rat primary visual cortex (V1) at a supra-threshold level with various frequencies, and recorded local field potentials (LFPs) at the infragranular stimulation site, the cortical surface site immediately above the stimulation site in V1, and cortical surface sites outside V1. We found a significant reduction of LFP powers during radial propagation, especially at high-frequency stimulation conditions. Moreover, low-gamma-band dominant rhythms were transiently induced during radial propagation. Contrastingly, inter-areal LFP propagation, directed to specific cortical sites, accompanied no significant signal reduction nor gamma-band power induction. We propose an anisotropic mechanism for signal processing in the spiking cortical network, in which the neuronal rhythms are locally induced/modulated along the radial direction, and then propagate without distortion via intrinsic horizontal connections for spatiotemporally precise, inter-areal communication.

The stress reaction of trainees is an issue in the practices of medical-related examinations that involve real-time decision making based on the examiner–subject interactions. The Goldmann perimetry (GP) test is one of these examinations. To evaluate the students’ stress reactions in the practice of the GP test, the stress-related substances and heart rate variability were measured in forty students enrolled in the practice. While there was no significant increase in stress-related substances during the practice, significantly increased sympathetic activities were observed at the beginning of the tests. Moreover, the plasma cortisol measured before the tests showed a significant positive correlation to the students’ self-confidence scores, indicating the students, especially those with higher self-confidence scores, were anxious for upcoming tests with unfamiliar subjects. Once the tests began, they felt relieved in the procedures they had learned repeatedly. On the other hand, while the average plasma ACTH decreased significantly during the test, the ACTH secretion correlated positively to the test duration, indicating that the skillful participants had less stress during the test. In the medical-related practices, pre-training on how to deal with unfamiliar subjects may be helpful for reducing the stress of the trainees, in addition to the procedure itself.

To devise a new formula for predicting the intraocular lens (IOL) position after cataract surgery using anterior segment optical coherence tomography (AS-O

Background: The cover–uncover test is traditionally used in the qualitative assessment of heterotropia and heterophoria, while the alternate prism cover test (APCT) quantifies ocular deviations. However, the APCT is time-consuming and prone to interexaminer variability. Video-oculography technology offers a promising alternative for quantifying ocular deviation under occlusion. This study aims to visualize ocular deviation during occlusion and determine the time it takes for deviation to stabilize in participants with exodeviation using the ORTe EYENAC eye-tracking system. Methods: The study participants included 15 university students aged 20–22 years, among whom 13 had exophoria, 1 had intermittent exotropia, and 1 had exotropia. Eye position was measured using the ORTe EYENAC, which records gaze when one eye is occluded. Data were fitted to a logistic function to estimate ocular deviations, deviation speed, and stabilization time. The overshoot depth was defined as the maximum deviation beyond the final position before stabilization. Spearman’s rank correlation coefficient analyzed the correlations between the deviation angle, speed, and stabilization time. Results: The fusion-free eye position stabilized at 3.33 ± 2.39 s among those with exophoria. Significant correlations were found between the deviation angle and deviation speed (r_s = − 0.582, p = 0.0403), as well as between the deviation angle and stabilization time (r_s = 0.663, p = 0.0135). An overshoot of > 1°, 0.5°–1.0°, and < 0.5° was seen in 3, 4, and 6 patients, respectively. The overshoot depth also correlated with deviation speed (r_s = 0.775, p = 0.0029). Conclusions: Ocular deviation under occlusion was effectively visualized in participants with exodeviation using the ORTe EYENAC, providing a clear representation of eye movement during the cover test. Among participants with exophoria, the fusion-free eye position stabilized at an average of 3.33 ± 2.39 s. However, the stabilization time varied with the angle of ocular deviation, suggesting that the occlusion time needs to be individually designed based on the angle of strabismus.