Pupillometry Analysis of Rapid Serial Visual Presentation at Five Presentation Rates

In this study,the effect of presentation rates on pupil dilation is investigated for target recognition in the Rapid Serial Visual Presentation(RSVP)paradigm.In this experiment,the RSVP paradigm with five different presentation rates,including 50,80,100,150,and 200 ms,is designed.The pupillometry data of 15 subjects are collected and analyzed.The pupillometry results reveal that the peak and average amplitudes for pupil size and velocity at the 80-ms presentation rate are considerably higher than those at other presentation rates.The average amplitude of pupil acceleration at the 80-ms presentation rate is significantly higher than those at the other presentation rates.The latencies under 50-and 80-ms presentation rates are considerably lower than those of 100-,150-,and 200-ms presentation rates.Additionally,no considerable differences are observed in the peak,average amplitude,and latency of pupil size,pupil velocity,and acceleration under 100-,150-,and 200-ms presentation rates.These results reveal that with the increase in the presentation rate,pupil dilation first increases,then decreases,and later reaches saturation.The 80-ms presentation rate results in the largest point of pupil dilation.No correlation is observed between pupil dilation and recognition accuracy under the five presentation rates.

Comparative study measuring the dilatory effect of a mydriatic device(Mydriasert~) versus topical drops

AIM:To compare the mydriatic efficacy of an ophthalmic insert(Mydriasert,MY)versus phenylephrine and tropicamide(PT)eye drops.METHODS:Two controlled,prospective,randomized,single-blind studies were performed.In the first study,a total of 80 eyes from 40 outpatient-clinic patients were analyzed.PT drops were applied to the right eye,and a MY device was inserted in the left eye for 30min.Time until maximal pupil dilation for each eye was then assessed.In the second study,80 eyes from 80 patients undergoing cataract surgery were analyzed.Pupil dilation was achieved using either PT drops three-times for one hour prior to surgery(40 patients),or a MY device was inserted one hour prior to surgery(40 patients).RESULTS:In the first study,MY achieved superior mydriasis compared to PT eye drops at 90min(9.04±1.33mm vs 8.78±1.37mm,P=0.012).However MY took longer than PT drops to achieve maximal dilation,and mydriasis was inferior in eyes with MY compared to PT drops at 30min(7.21±1.73mm vs 8.22±1.43mm,P【0.001),the two groups only becoming similar by 60min(8.85±1.44mm vs 8.71±1.27mm,P=0.236).In the second study,both MY and PT achieved similar levels of mydriasis at the beginning of surgery(8.75±0.76mm with MY vs 8.77±0.63mm with PT),and also at the end of surgery(7.96±1.06mm with MY vs 8.32±0.72mm with PT),with no significant difference between groups(P=0.08).MY was well tolerated and cardiovascular effects were not influenced by dilation method.CONLUSION:MY could be a safe and efficacious alternative for mydriasis.The mydriatic effect of MY is as good as conventional PT eye drops after 60min,and is superior after 90min.MY also maintains good pupil dilation during cataract surgery.

Cognitive Workload Assessment of Aircraft Pilots

In this research, we study the cognitive workload of aircraft pilots during a simulated takeoff procedure. We propose a proof-of-concept setup environment to gather heart rate, pupil dilation, and brain cognitive workload data during an A320 takeoff within a simulator. Experiments were performed during which we collected 136 takeoffs across 13 pilots for more than 9 hours of time-series data. Moreover, this paper investigates the correlations between heart rate, pupil dilation, and cognitive workload during such exercise and found that a spike in cognitive load during a critical moment, such as an engine failure, augments a pilot’s heart rate and pupil dilation. Results show that a critical moment within a takeoff procedure increases a pilot’s cognitive load. Next, we used a stacked-LSTM model to predict cognitive workload 5 seconds into the future. The model was able to produce accurate predictions.