Pupillometric evidence for perceptual simulation in language comprehension: Sensory and emotional meanings of Japanese adjectives.

Pupillometry is the scientific study of pupil size changes due to low-level factors like ambient lighting conditions and changes in focal distance, and, more interestingly, due to higher level brain activity and attentional, emotional, or cognitive demands. Because it offers a way to assess cognitive activity, pupillometry has attracted research gauging cognitive processing effort on and off since the 1960s. Due to developments in eye tracking technology and statistical analysis methods, pupillometry has enjoyed a renewed interest as a tool for language processing research since the 2010s. Language processing tasks using Task-Evoked Pupillary Response (TEPR)—measured changes in pupil dilation time-locked to the presentation of a stimulus—have shown that the human pupil responds to and can be used to replicate many of the standard findings in the psycholinguistic literature. For example, pupil size varies with lexical frequency during word processing tasks, showing more dilation for low than for high frequency words. Similarly, changes in pupil size correlate with differences in complexity, ambiguity, predictability, and ease of contextual integration during sentence processing. Perhaps most interestingly, pupillometry responds to processing demands induced by pragmatic inferences. Further, it is sensitive to several individual difference factors, for the investigation of which it offers a non-invasive, task-free method. This is without doubt one of the most attractive sides of pupillometry: it can be used to investigate many factors influencing spoken language processing effort, including pragmatics and socially situated language processes, and it can be used to do so without an explicit task and with natural, felicitous spoken stimuli. However, the literature reporting use of pupillometry in psycholinguistics is still very sparse, so more research is needed to find the areas where pupillometry is both reliable and useful, and where it independently benefits research in language sciences, not just replicates results and phenomena obtained from other, more established methods. Current developments in data preprocessing, statistical methods, and eye tracking technology carry some promise that this time, pupillometry might have come to stay as one more useful method in a psycholinguist’s toolbox.

Brimonidine and pupillary diameter

In order to explore the percentage change in pupil size that can represent the generation of irritability, the experiment of inducing irritability was designed. The pupil diameter of the participants was collected by eye movement instrument, and the data of percentage change in pupil size at different levels of irritability was analyzed by combining the subjective score table. The results showed that the percentage change in pupil size was different in different participants when the irritability level reached level 5, but generally ranged between 10% and 25%. Besides, with the constant deepening of the level of irritability, the percentage change in pupil size is increasing. Therefore, the percentage change in pupil size can be used as a measure of irritability, providing certain reference for the monitoring of irritability of operators in special positions.

If the effects of variations in brightness can be controlled, it is possible to use changes in pupil size for the evaluation of educational TV programs. This paper describes an improved, neural-network-based method for studying pupil reactions and the feasibility of evaluating TV programs by investigating changes in pupil size. This neural-network pupil reaction model uses M-sequences and Markov-sequences to register changes in pupil size based upon responses to changes in brightness, and this paper shows it to be more effective in removing the effects of brightness on pupil size than other previously reported methods. The authors also discuss methods for removing the influence of brightness from pupil response, as well as methods for evaluating changes in pupil size. It is also shown that this new method permits the objective evaluation of TV programs through the measurement of changes in pupil size while viewing TV programs.

Event Abstract Back to Event A comparison of processing load during non-verbal decision-making in two individuals with aphasia Salima Suleman1*, Esther S. Kim1 and Tammy Hopper1 1 University of Alberta, Canada INTRODUCTION A growing body of evidence suggests people with aphasia (PWA) can have impairments to cognitive functions such as attention, working memory and executive functions.(1-5) Such cognitive impairments have been shown to negatively affect the decision-making (DM) abilities adults with neurological damage. (6,7) However, little is known about DM abilities of PWA.(8) Pupillometry is “the measurement of changes in pupil diameter”.(9;p.1) Researchers have reported a positive relationship between processing load and phasic pupil size (i.e., as processing load increases, pupil size increases).(10) Thus pupillometry has the potential to be a useful tool for investigating processing load during DM in PWA. AIMS The primary aim of this study was to establish the feasibility of using pupillometry during a non-verbal DM task with PWA. The secondary aim was to explore non-verbal DM performance in PWA and determine the relationship between DM performance and processing load using pupillometry. METHOD DESIGN. A single-subject case-study design with two participants was used in this study. PARTICIPANTS. Two adult males with anomic aphasia participated in this study. Participants were matched for age and education. Both participants were independent, able to drive, and had legal autonomy. MEASURES. PERFORMANCE ON A DM TASK. We used a computerized risk-taking card game called the Iowa Gambling Task (IGT) as our non-verbal DM task.(11) In the IGT, participants made 100 selections (via eye gaze) from four decks of cards presented on the computer screen with the goal of maximizing their overall hypothetical monetary gain. PROCESSING LOAD. The EyeLink 1000+ eye tracking system was used to collect pupil size measures while participants deliberated before each deck selection during the IGT. For this analysis, we calculated change in pupil size as a measure of processing load. RESULTS P1. P1 made increasingly advantageous decisions as the task progressed (Fig.1). When asked to rank order the decks, P1 consistently identified the advantageous decks as the best decks after block two. We found a significant negative non-parametric correlation between trial and change in pupil size (rs = - 0.481, n = 100, p < 0.0001). P2. P2 made increasingly disadvantageous decisions as the task progressed (Fig. 1). When asked to rank the decks, P2 was unable to accurately and consistently identify advantageous decks at the end of the task. At the end of block five, P2 stated “I didn’t have the sense of ‘that was going to be the good one’”. We found a significant negative correlation between change in pupil size and trial number (rs = - 0.379, n = 100, p < 0.0001). DISCUSSION Two participants with similar aphasia demonstrated disparate DM performance. P1 quickly determined the way to maximize his gain, while P2 was unable to discern the best way to maximize his gain and made more disadvantageous decisions as the task progressed. Both participants showed decreasing changes in pupil size related to processing load. These results demonstrate the feasibility of using pupillometry in a computerized DM task with PWA. Further, we know that even when language profiles are similar, DM abilities may be differentially affected in aphasia. These preliminary data will be used to inform a subsequent, larger study of DM in PWA. Figure 1 References

To determine changes in entrance pupil size and pupil center shift under low mesopic and photopic conditions of illumination in eyes with in-the-bag intraocular lens (IOL) implantation. Entrance pupil size and pupil center shift were measured under low mesopic (0.06 lux) and photopic (60 lux) conditions of illumination in 55 patients with unilateral pseudophakia (study group) and 55 age- and sex-matched patients with bilateral cataracts (control group) using the NIDEK OPD-Scan. Pseudophakic eyes had an uncomplicated intraoperative and postoperative course and best spectacle-corrected visual acuity of 20/20. Cataractous eyes had no additional ocular or systemic problems affecting the pupil. Both groups were analyzed with respect to pupil size and shift in both conditions of illumination. Mean patient age was 64.2 +/- 6.8 and 63.6 +/- 4.3 years in the study and control groups, respectively (P = .45). In the study group, differences in pupil size under low mesopic (5.12 +/- 1.02 and 5.13 +/- 0.96 mm for pseudophakic and phakic eyes, respectively) and photopic (3.44 +/- 0.39 and 3.45 +/- 0.39 mm for pseudophakic and phakic eyes, respectively) conditions of illumination were not statistically significant (P = 1.00 and P = .95 for pseudophakic and phakic eyes, respectively). Differences in pupil shift between pseudophakic (0.11 +/- 0.08 mm) and phakic (0.12 +/- 0.10 mm) eyes were not statistically significant (P = .83) in the study group. In the control group, differences in pupil size under low mesopic (P = .59) and photopic conditions of illumination (P = .60) in the right and left eyes as well as pupil shift (P = .71) were not statistically significant. Uncomplicated in-the-bag IOL implantation has no influence on pupil size and shift.

Digital pupillometry and centroid shift changes after cataract surgery

Existing literature reveals little information about the relationship between microsaccade rate and the average change in pupil size. There is a need to investigate this relationship and how the microsaccade rate may be relevant to cognitive load. In our study, we compared the microsaccade rate to the average change in pupil size during eight experimental conditions. Four of them were considered fixation conditions (subjects look at a fixation cross in each visual scene) and four were free-viewing conditions (subjects are free to move their eyes over the visual scene). We analyzed the change in pupil size and microsaccade rate for the first part of each task and as well as the entire task in all conditions. We discovered a significant correlation between the microsaccade rate and the average change in pupil size during the first part of each task, and comparable characteristics throughout the entire task. Then we measured the data for only one of the experimental conditions in free-viewing that involves a search task to understand comparable characteristics related to cognitive load. We found that there is a correlation between the microsaccade and pupil data. We hope that this finding will help further the understanding of the relative function of microsaccades and use it to support cognitive load response and pupil measurement.

Research suggests that listeners’ comprehension of spoken language is concurrently affected by linguistic and non-linguistic factors, including individual difference factors. However, there is no systematic research on whether general personality traits affect language processing. We correlated 88 native English-speaking participants’ Big-5 traits with their pupillary responses to spoken sentences that included grammatical errors, "He frequently have burgers for dinner"; semantic anomalies, "Dogs sometimes chase teas"; and statements incongruent with gender stereotyped expectations, such as "I sometimes buy my bras at Hudson's Bay", spoken by a male speaker. Generalized additive mixed models showed that the listener's Openness, Extraversion, Agreeableness, and Neuroticism traits modulated resource allocation to the three different types of unexpected stimuli. No personality trait affected changes in pupil size across the board: less open participants showed greater pupil dilation when processing sentences with grammatical errors; and more introverted listeners showed greater pupil dilation in response to both semantic anomalies and socio-cultural clashes. Our study is the first one demonstrating that personality traits systematically modulate listeners’ online language processing. Our results suggest that individuals with different personality profiles exhibit different patterns of the allocation of cognitive resources during real-time language comprehension.

BackgroundAs a side effect of interscalene brachial plexus block (ISBPB), stellate ganglion block (SGB) causes reductions in pupil size (Horner’s syndrome) and cardiac sympathetic nervous activity (CSNA). Reduced CSNA is associated with hemodynamic instability when patients are seated. Therefore, instantaneous measurements of CSNA are important in seated patients presenting with Horner’s syndrome. However, there are no effective tools to measure real-time CSNA intraoperatively. To evaluate the usefulness of pupillometry in measuring CSNA, we investigated the relationship between pupil size and CSNA.MethodsForty-two patients undergoing right arthroscopic shoulder surgery under ISBPB were analyzed. Pupil diameters were measured at 30 Hz for 2 s using a portable pupillometer. Bilateral pupil diameters and CSNA (natural-log-transformed low-frequency power [0.04–0.15 Hz] of heart rate variability [lnLF]) were measured before ISBPB (pre-ISBPB) and 15 min after transition to the sitting position following ISBPB (post-sitting). Changes in the pupil diameter ([right pupil diameter for post-sitting – left pupil diameter for post-sitting] – [right pupil diameter for pre-ISBPB – left pupil diameter for pre-ISBPB]) and CSNA (lnLF for post-sitting – lnLF for pre-ISBPB) were calculated.ResultsForty-one patients (97.6%) developed Horner’s syndrome. Right pupil diameter and lnLF significantly decreased upon transition to sitting after ISBPB. In the linear regression model (R2 = 0.242, P = 0.001), a one-unit decrease (1 mm) in the extent of changes in the pupil diameter reduced the extent of changes in lnLF by 0.659 ln(ms2/Hz) (95% CI [0.090, 1.228]).ConclusionsPupillometry is a useful tool to measure changes in CSNA after the transition to sitting following ISBPB.

Introduction Acute cannabis use has been found to affect pupil size and pupillary dynamics. Law enforcement may consider ocular changes in their examinations to determine drug impairment and the source, including from cannabis. A limited number of studies have used pupillometer technology to provide an objective measure of pupillary changes associated with cannabis use. The purpose of the study was to examine the sensitivity and specificity of pupil size and dynamics, measured with a pupillometer, associated with recent cannabis inhalation. Methods Participants (n = 126) completed a pupillometer assessment, using the NeurOptics PLR-3000 at three times. Of the 126 participants, 95 completed assessments at baseline, and at 40 min and 100 min following 15 min of ad libitum inhalation of self-provided cannabis flower or concentrate products. Thirty-one participants completed the same assessments without using cannabis. Sensitivity, specificity and accuracy were calculated for pupil size and dynamics measures associated with recent cannabis use versus no use, for both post-use time points. Least absolute shrinkage and selection operator models were used to identify the combination of ocular metrics that were most predictive and parsimonious. Results Following cannabis use, the pupillary measure with the highest area under the curve was percent change in pupil size, which decreased after cannabis use, with an area under the curve of 0.73 at 40 min and 0.75 at 100 min following cannabis use. Considering variables together in a least absolute shrinkage and selection operator model did not meaningfully improve prediction over individual measures. Discussion Consistent with some prior studies, we did not find that cannabis use was associated with substantial and consistent change in the maximum pupil size (measured in darkness) relative to controls. However, diminished pupil dynamics, such as constriction in response to light and recovery dilation, were more predictive of recent cannabis use, consistent with limited prior studies. Conclusions Pupillary dynamics, when measured with an objective test, may contribute to providing an indication of recent cannabis inhalation.

To evaluate the changes in intraocular pressure and pupil size in glaucomatous dogs after instillation of 0.005% latanoprost (Xalatan, Pharmacia and Upjohn, Kalamazoo, MI, USA) once in the morning, or once in the evening, or twice daily in five-day multiple-dose studies. Animals studied Eight Beagles with the moderate stage of inherited primary open-angle glaucoma. Applanation tonometry (IOP) and pupil size (PS) measurements were obtained at 8 am, 10 am, 12 noon, 2 pm, and 4 pm in eight glaucoma dogs. Methylcellulose (0.5% as placebo) was instilled in the control eye, and 0.005% latanoprost was instilled in the opposite drug eye. Control and drug eyes were selected using a random table. For these three studies, 0.5% methylcellulose and 0.005% latanoprost were instilled the second through the fifth days with instillations in the morning (8.30 am), or evening (8 pm), or twice daily (8.30 am and 8 pm). Statistical comparisons between drug groups included control, placebo, and treated (0.005% latanoprost) eyes for three multiple-dose studies. In the 8-am latanoprost study, the mean +/- SEM diurnal declines in IOP for the placebo and drug eyes for the first day were 6.5 +/- 3.6 mmHg and 8.4 +/- 4.0 mmHg, respectively. The mean +/- SEM diurnal changes in IOP after 0.005% latanoprost at 8 am once daily for the next four days were 23.3 +/- 5.0 mmHg, 25.4 +/- 2.1 mmHg, 25.7 +/- 1.7 mmHg, and 26.1 +/- 1.7 mmHg, respectively, and were significantly different from the control eye. A significant miosis also occurred starting 2 h postdrug instillation, and the resultant mean +/- SD pupil size was 1.0 +/- 0.1 mm. In the first day of the second latanoprost study, the mean +/- SEM diurnal changes in the placebo and drug eye IOPs were 11.6 +/- 3.8 mmHg, and 12.0 +/- 4.4 mmHg, respectively. For the following four days with latanoprost instilled at 8 pm, the mean +/- SEM diurnal changes in IOP in the drug eyes were 24.9 +/- 2.1 mmHg, 22.4 +/- 1.8 mmHg, 21.6 +/- 1.9 mmHg, and 26.6 +/- 2.2 mmHg, respectively. Compared to the fellow placebo eyes, the diurnal changes in IOP were significantly different. Significant changes in pupil size were similar to the IOP changes, with miosis throughout the day and return to baseline pupil size the following morning before drug instillation. In the last study, the mean +/- SEM diurnal changes in IOP for the placebo and drug eyes for the first day were 6.6 +/- 2.1 mmHg and 9.4 +/- 2.8 mmHg, respectively. For the four subsequent days with latanoprost instilled twice daily, the mean +/- SEM diurnal IOP changes were 19.6 +/- 1.5 mmHg, 19.1 +/- 1.4 mmHg, 19.9 +/- 1.7 mmHg, and 20.3 +/- 0.7 mmHg, respectively, and were significantly different from the placebo eyes. The mean changes in PS were 3.1 +/- 0.7 mm. 0.005% latanoprost instilled once daily (am or pm) as well as twice daily produces significant decreases in IOP and PS in the glaucomatous Beagle. The evening instillation of 0.005% latanoprost produced less daily fluctuations in IOP than when the drug was instilled in the morning. 0.005% latanoprost instilled twice daily produced the greatest decline in IOP with the least daily fluctuations, but longer duration miosis.

Prefrontal activation and pupil dilation during n-back task performance: A combined fNIRS and pupillometry study

Comparing the Ability of Perceptual Simulation in Children with Developmental Dyslexia and Typical Children: An Embodied Cognition View

Two experiments examined the effectiveness of the pupillary response as a measure of cognitive load in younger and older adults. Experiment 1 measured the change in pupil size of younger and older adults while they listened to spoken digit lists that varied in length and retained them briefly for recall. In Experiment 2 changes in relative pupil size were measured while younger and older adults listened to sentences for later recall that varied in syntactic complexity and sentence length. Both age groups' pupil sizes were sensitive to the size of the memory set in Experiment 1 and sentence length in Experiment 2, with the older adults showing a larger effect of the memory load on a normalized measure of pupil size relative to the younger adults. By contrast, only the younger adults showed a difference in the pupillary response to a change in syntactic complexity, even with an adjustment for the reduced reactivity of the older pupil.