Coupling between Trigeminal-Induced Asymmetries in Locus Coeruleus Activity and Cognitive Performance

In humans, the asymmetry in the masseter electromyographic (EMG) activity during clenching is positively correlated with the degree of pupil size asymmetry (anisocoria) at rest. Anisocoria reveals an asymmetry in LC activity, which may lead to an imbalance in cortical excitability, detrimental to performance. Hereby, we investigated, in individual subjects, the possibility that occlusal correction, which decreases EMG asymmetry, improves performance by balancing LC activity. Cognitive performance, task-related mydriasis, and pupil size at rest were modified by changing the occlusal condition. Occlusal-related changes in performance and mydriasis were negatively correlated with anisocoria changes in only 12/20 subjects. Within this population, spontaneous fluctuations in mydriasis and anisocoria also appeared negatively coupled. Occlusal-related changes in performance and mydriasis were negatively correlated with those in average pupil size (a proxy of average LC activity) in 19/20 subjects. The strongest association was observed for the pupil changes occurring on the side with higher EMG activity during clenching. These findings indicate that the effects of occlusal conditions on cognitive performance were coupled to changes in the asymmetry of LC activity in about half of the subjects, while they were related to changes in the average tonic LC activity in virtually all of them.

Effect of over-the-counter brimonidine tartrate 0.025% ophthalmic solution on pupil size in healthy adults

Purpose To evaluate the effect of brimonidine tartrate 0.025% ophthalmic solution on pupil size under scotopic conditions in healthy adults Methods Pupil size was measured in 56 eyes of 28 volunteer participants using a pupillometer under scotopic conditions. Age, gender, and iris color were recorded. Subjects using any ophthalmic medications other than artificial tears were excluded. The pupil size was subsequently measured again under scotopic conditions 60 min after instillation of brimonidine tartrate 0.025% ophthalmic solution. Results Statistically significant miosis was seen after instillation of brimonidine tartrate 0.025% (p = 0.04). Average pupil size prior to brimonidine 0.025% instillation was 7.28 ± 1.05 mm, and average pupil size after instillation of brimonidine 0.025% was 6.36 ± 1.68 mm, a reduction of − 23.7% in pupil area. Subjects with light irides demonstrated a greater miotic effect than subjects with dark irides (1.55 mm vs. 0.67 mm, p < 0.0001), with a pupil area reduction of − 37.6% and − 17.4%, respectively. The amount of miosis was independent of initial pupil size. Conclusions Brimonidine tartrate 0.025% causes significant miosis in scotopic settings, although the effect is not as great in darker colored eyes. Further studies are needed to determine the latency and duration of the effect and whether the amount of miosis is clinically significant.

Model of Driver’s Eye Movement and ECG Index under Tunnel Environment Based on Spatiotemporal Data

In order to improve the driver’s physiological and psychological state, the driver’s mental load which is caused by sight distance, lighting, and other factors in the tunnel environment should be quantified via modeling the spatiotemporal data. The experimental schemes have been scientifically designed based on methods of traffic engineering and human factor engineering, which aims to test the driver’s spatiotemporal data of eye movement and ECG (electrocardiogram) index in the tunnel environment. Firstly, the changes in the driver’s spatiotemporal data are analyzed to judge the changing trend of the driver’s workload in the tunnel environment. The results show that the cubic spline interpolation function model can fit the dynamic changes of average pupil diameter and heart rate (HR) growth rate well, and the goodness of fit for the model group is above 0.95. So, tunnel environment makes the driver’s typical physiological indicators fluctuate in the coordinates of time and space, which can be modeled and quantified. Secondly, in order to analyze the classification of tunnel risk level, a fusion model has been built based on the functions of average pupil diameter and HR growth rate. The tunnel environmental risk level has been divided into four levels via the fusion model, which can provide a guidance for the classification of tunnel risk level. Furthermore, the fusion model allows tunnel design and construction personnel to adopt different safety design measures for different risk levels, and this method can effectively improve the economy of tunnel operating safety design.

Evaluation of disk halo size after small incision lenticule extraction (SMILE)

Purpose To investigate changes in objective disk halo size produced by a glare source after small incision lenticule extraction (SMILE) for myopia correction. Methods This prospective clinical study included 45 right eyes of 45 patients with a mean age of 25.40 ± 5.06 years and mean spherical equivalent (SE) of − 6.08 ± 1.90 diopters. Disk halo size was measured with a vision monitor before surgery and at postoperative 1 week and 3 months. Other information was collected, including age, SE, lenticule thickness, lenticule diameter, dark pupil, and pupillary response to light parameters (initial diameter; amplitude, latency, duration, and velocity of contraction; latency, duration, and velocity of dilation; and maximum, minimum, and average pupil size). Results Compared to preoperative values, disk halo size increased significantly at postoperative 1 week (P = 0.026) and returned to baseline at postoperative 3 months (P = 0.349). Preoperative disk halo size significantly correlated with SE (r = − 0.346, P = 0.020), minimum pupil size (r = 0.365, P = 0.014), and average pupil size (r = 0.310, P = 0.038). Disk halo size at postoperative 1 week was significantly correlated with age (r = 0.324, P = 0.030) and minimum pupil size (r = 0.297, P = 0.047). Disk halo size at postoperative 3 months was significantly correlated with lenticule diameter (r = − 0.362, P = 0.015), initial diameter (r = 0.311, P = 0.037), maximum pupil size (r = 0.312, P = 0.037), minimum pupil size (r = 0.440, P = 0.002), and average pupil size (r = 0.373, P = 0.012). Conclusions After SMILE, disk halo size demonstrated a temporary increase and then returned to baseline.

Evaluation of Disk Halo Size after Implantation of a Collamer Lens with a Central Hole (ICL V4c)

Purpose. To investigate disk halo size changes produced by a glare source after surgical insertion of an implantable collamer lens with a central hole (ICL V4c) for myopia correction. Methods. In this prospective study, disk halo size and pupillary light response with a vision monitor were measured preoperatively and at 1 week, 1 month, and 3 months postoperatively. Pupillary light response parameters included contraction amplitude, latency, duration, and velocity; dilation latency, duration, and velocity; and initial, maximum, minimum, and average pupil diameters. Results. Forty-two right eyes of 42 patients were enrolled. Postoperative uncorrected distance visual acuity was better than or equal to 20/20 in all eyes. Compared to preoperative values, disk halo size showed no significant difference at 1 week postoperatively (P>0.05) and then decreased significantly at 1 and 3 months postoperatively (both P<0.001). Contraction amplitude and velocity, as well as dilation velocity, decreased significantly at all postoperative time points (all P<0.001). Disk halo size at 3 months postoperatively was significantly correlated with initial (r = 0.446, P=0.003), maximum (r = 0.483, P=0.001), minimum (r = 0.425, P=0.005), and average pupil diameters (r = 0.474, P=0.002). Conclusions. After ICL V4c implantation, disk halo size was reduced in the short term. Patients with smaller pupil sizes during pupillary response to light experienced smaller halos after ICL V4c implantation.

Pulses of melanopsin-directed contrast produce highly reproducible pupilresponses that are insensitive to a change in background radiance

PurposeTo measure the pupil response to pulses of melanopsin-directed contrast, and compare this response to those evoked by cone-directed contrast and spectrally-narrowband stimuli.Methods3-second unipolar pulses were used to elicit pupil responses in human subjects across 3 sessions. Thirty subjects were studied in Session 1, and most returned for Sessions 2 and 3. The stimuli of primary interest were “silent substitution” cone‐ and melanopsin-directed modulations. Red and blue narrowband pulses delivered using the post-illumination pupil response (PIPR) paradigm were also studied. Sessions 1 and 2 were identical, while Session 3 involved modulations around higher radiance backgrounds. The pupil responses were fit by a model whose parameters described response amplitude and temporal shape.ResultsGroup average pupil responses for all stimuli overlapped extensively across Sessions 1 and 2, indicating high reproducibility. Model fits indicate that the response to melanopsin-directed contrast is prolonged relative to that elicited by cone-directed contrast. The group average cone‐ and melanopsin-directed pupil responses from Session 3 were highly similar to those from Sessions 1 and 2, suggesting that these responses are insensitive to background radiance over the range studied. The increase in radiance enhanced persistent pupil constriction to blue light.ConclusionsThe group average pupil response to stimuli designed through silent substitution provides a reliable probe of the function of a melanopsin-mediated system in humans. As disruption of the melanopsin system may relate to clinical pathology, the reproducibility of response suggests that silent substitution pupillometry can test if melanopsin signals differ between clinical groups.

Pupillometry: The Influence of Gender and Anxiety on the Pain Response

Background: Studies suggest that the pain response may be evaluated using pupillometry and is influenced by factors such as gender and anxiety. Objectives: The aim of this study was to use pupillometry to observe the effects of gender and anxiety on the pain response. Study Design: A randomized, prospective, clinical and interventional study. Setting: Center for Research on Pain at the Federal University of Maranhão, Brazil. Methods: Ninety-six patients were divided into groups according to their level of anxiety as indicated by the Beck questionnaire. Under photopic conditions and using retinography, these patients underwent pupillometry while a painful pressure stimulus of 1,500 kPa was applied to the middle phalanx of each patient’s right middle finger using a pressure algometer. Results: The pupil diameter increased in response to pain in all study participants, regardless of gender and anxiety level; the average pupil diameter was 3.265 ± 0.028 mm before the painful stimulus and 4.31 ± 0.200 mm for the duration of the stimulus (P = 0.0251). There was no significant difference between the genders in the level of anxiety (P = 0.614). Regardless of gender, individuals with moderate to severe anxiety had higher average pupil diameters than individuals exhibiting mild or no anxiety (P = 0.019). Men had a higher average pupil diameter than women (4.53 ± 0.345 mm and 4.48 ± 0.358 mm, respectively); however, this difference was not statistically significant in the presence of moderate to severe anxiety (P = 0.072). Limitations: The number of men with high anxiety was insufficient to create their own group. Conclusions: The pupil dilation in response to a painful stimulus was similar in both genders. Additionally, regardless of gender, the average pupil diameter was greater in the presence of moderate to severe anxiety. Key words: Pupillometry, pain, gender, anxiety

The Superior Educational Attainments of Pupils in Religious Foundation Schools in England

Pupils of religious foundation schools in England show superior educational performance over general (Local Education Authority) schools, the advantage having been estimated in previous studies at learning about a tenth faster for the average pupil by the age of leaving primary schooling (age 11+). In this study access to individual pupils' scores at SAT tests shows that the advantage of religious foundation schools is particularly great for lower-attaining pupils, with only the lowest tenth of those in religious schools attaining the scores of the lowest third in general schools.

Pupil Dilation as a Measure of Processing Load in Simultaneous Interpretation and Other Language Tasks

The present study tested whether the pupillary response can be applied to study the variation in processing load during simultaneous interpretation. In Experiment 1, the global processing load in simultaneous interpretation as reflected in the average pupil size was compared to that in two other language tasks, listening to and repeating back an auditorily presented text. Experiment 1 showed clear differences between the experimental tasks. In Experiment 2, the task effect was replicated using single words as stimuli. Experiment 2 showed that momentary variations in processing load during a lexical translation task are reflected in pupil size. Words that were chosen to be more difficult to translate induced higher levels of pupil dilation than did easily translatable words. Moreover, repeating back words in a non-native language was accompanied by increased pupil dilations, in comparison to repetition in the subject's native language. In sum, the study lends good support to the use of the pupillary response as an indicator of processing load.

Science and Religion: Partners in Education?

Believing as I do that the ‘problem’ of science and religion is not a problem at all, provided that each is seen in the correct way and that each does not try to encroach upon the other, it will be my purpose in this paper to point out some of the difficulties in educating secondary school pupils into this fact. In popular thought, and in the thought of the average pupil, science produces severe problems for the religious believer, and it is assumed that the scientist is the purveyor of truth, whilst the religious believer is one who clings to unscientific beliefs in the attempt to hold on to his faith. In popular thought a scientist could not believe in religion because science has supposedly disproved the foundations of religion piece by piece over the centuries. Such a view, however, of science and religion is totally wrong.