scholarly journals The confounding effects of eye blinking on pupillometry, and their remedy

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261463
Author(s):  
Kyung Yoo ◽  
Jeongyeol Ahn ◽  
Sang-Hun Lee

Pupillometry, thanks to its strong relationship with cognitive factors and recent advancements in measuring techniques, has become popular among cognitive or neural scientists as a tool for studying the physiological processes involved in mental or neural processes. Despite this growing popularity of pupillometry, the methodological understanding of pupillometry is limited, especially regarding potential factors that may threaten pupillary measurements’ validity. Eye blinking can be a factor because it frequently occurs in a manner dependent on many cognitive components and induces a pulse-like pupillary change consisting of constriction and dilation with substantive magnitude and length. We set out to characterize the basic properties of this “blink-locked pupillary response (BPR),” including the shape and magnitude of BPR and their variability across subjects and blinks, as the first step of studying the confounding nature of eye blinking. Then, we demonstrated how the dependency of eye blinking on cognitive factors could confound, via BPR, the pupillary responses that are supposed to reflect the cognitive states of interest. By building a statistical model of how the confounding effects of eye blinking occur, we proposed a probabilistic-inference algorithm of de-confounding raw pupillary measurements and showed that the proposed algorithm selectively removed BPR and enhanced the statistical power of pupillometry experiments. Our findings call for attention to the presence and confounding nature of BPR in pupillometry. The algorithm we developed here can be used as an effective remedy for the confounding effects of BPR on pupillometry.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e21042-e21042
Author(s):  
Eduardo Richardet ◽  
Luciana Paola Acosta ◽  
Maria gimena Ferreira ◽  
Ignacio Magi ◽  
Rocio tello Alfonso ◽  
...  

e21042 Background: There exists a strong relationship between cancer and inflammation. For this reason, attempts have been made to identify different biomarkers of inflammation in recent years. The neutrophil - lymphocyte ratio (NLR) a marker of systemic inflammation, and the infiltranting lymphocytes of the tumor stroma (TILs) have been studied by our research team in different tumors, such as melanoma, breast cancer, colon cancer and NSCLC in patient who had recieved tratment with chemotherapy. We could observe that there was a significant relationship beteween DFS and a high NLR on the one hand, and DSF an intense TILs on the other. Our main objective is to evaluate the relationship between the objective response rate (ORR) and the pretreatment NLR in patients with advanced NSCLC who recieved immunotherapy. Our secondary objective is to analyzed the associated between PFS and RNL in patients with advanced NSCLC undergoing immunotherapy. Methods: Patients with diagnosis of advanced-stage NSCLC who recieved only immunotherapy, immunotherapy with another immunomodulator or in combination with platinum-based chemotherapy werw included. All patients had a follow-up of at least 6 months. The cutoff value > or < 3 for the NLR was use to reference. The laboratory control prior to the beginning of treatment was taken, and the ORR was determined using the Response Evaluation Criteria In Solid Tumors (RECIST) criteria. Statistical analysis was performed using dispersion and position measurements, T-Test and Chi Square test. For PFS analysis Kaplan-Meyer was used. The level of significance for the variables was p < 0.05. Results: 41 patients with advanced NSCLC were analyzed. 43.9% (18 pts) recieved immunotherapy alone with nivolumab. 34.14% (14 pts) received a combined treatment (nivo / ipi) and 21.95% (9 pts.), immuno / QT combination (based on platinum). Regarding the histological presentation, 80.48% were adenocarcinoma. 54% (22 pts) had an NLR > 3 and 46% (19 pts) an NLR < 3. The ORR in the general population was 24%. in pts with an NLR < 3, the ORR that was observed was 42% vs. ORR of 9% in pts with NLR > 3 (p: 0.02). These differences were statistically significant. The median PFS was 11.27 months in the general population. As regards RNL, the median PFS were 20.74 vs 5.52 months in favor of pts with an NLR < 3 (p: 0.04). Conclusions: We could conclude that patients with NSCLC and pretreatment NLR < 3, who undergo immunotherapy, had better ORR compared to those with NLR > 3. These differences was statistically significant. Also, we could observe better PFS in patient with NLR < 3. These difference was estatically significant. We will keep working to obtain a greater number of patients. Then we could have a better analysis and statistical power. It is possible that NLR will be a highly useful and easy-to-acces predictive factor, and it could be used in patients with immunotherapy in our daily practice.


2017 ◽  
Author(s):  
Sebastiaan Mathôt ◽  
Jasper Fabius ◽  
Elle van Heusden ◽  
Stefan Van der Stigchel

Measurement of pupil size (pupillometry) has recently gained renewed interest from psychologists, but there is little agreement on how pupil-size data is best analyzed. Here we focus on one aspect of pupillometric analyses: baseline correction, that is, analyzing changes in pupil size relative to a baseline period. Baseline correction is useful in experiments that investigate the effect of some experimental manipulation on pupil size. In such experiments, baseline correction improves statistical power by taking into account random fluctuations in pupil size over time. However, we show that baseline correction can also distort data if unrealistically small pupil sizes are recorded during the baseline period, which can easily occur due to eye blinks, data loss, or other distortions. Divisive baseline correction (corrected pupil size = pupil size / baseline) is affected more strongly by such distortions than subtractive baseline correction (corrected pupil size = pupil size - baseline). We make four recommendations for safe and sensible baseline correction of pupil-size data: 1) use subtractive baseline correction; 2) visually compare your corrected and uncorrected data; 3) be wary of pupil-size effects that emerge faster than the latency of the pupillary response allows (within ±220 ms after the manipulation that induces the effect); and 4) remove trials on which baseline pupil size is unrealistically small (indicative of blinks and other distortions).


2018 ◽  
Author(s):  
Sean Youn ◽  
Corey Okinaka ◽  
Lydia M Mäthger

AbstractThe little skate Leucoraja erinacea has elaborately shaped pupils, whose characteristics and functions have not been studied extensively. It has been suggested that such pupil shapes may camouflage the eye; yet, no experimental evidence has been presented to support this claim. Skates are bottom-dwellers that often bury into the substrate with their eyes protruding. If these pupils serve any camouflage function, we expect there to be a pupillary response related to the spatial frequency (“graininess”) of the background against which the eye is viewed. Here, we tested whether skate pupils dilate or constrict in response to background spatial frequency. We placed skates on background substrates with different spatial frequencies and recorded pupillary responses at three light intensities. In experiment 1, the skates’ pupillary response to three artificial checkerboards of different spatial frequencies was recorded. Skates responded to changing light intensity with pupil dilation/constriction; yet, their pupils did not change in response to spatial frequency. In experiment 2, in which skates could bury into three natural substrates with different spatial frequencies, such that their eyes protruded above the substrate, the pupils showed a subtle but statistically significant response to changes in substrate spatial frequency. Given the same light intensity, the smaller the spatial frequency of the natural substrate, the more constricted the pupil. While light intensity is the primary factor determining pupil dilation, these experiments are the first to show that pupils also change in response to background spatial frequency, which suggests that the pupil may aid in camouflaging the eye.


1989 ◽  
Vol 69 (3-2) ◽  
pp. 1351-1367
Author(s):  
Robert S. Sturgeon ◽  
Leslie M. Cooper ◽  
Robert J. Howell

15 highly aroused snake phobics individually constructed fear hierarchies by selecting colored photographs of snakes. Subjects either imagined fear scenes based on their photographs or were exposed to duplicate projected slides during desensitization. Pupillary responses of the Slide Group were also recorded before, during, and after desensitization. Fear of snakes was significantly reduced for both groups within five or fewer desensitization sessions. Changes in pupil size of the Slide Group appear to reflect arousal of fear as well as reduction of fear after treatment. Current technology makes pupillary response a viable psychophysiological measure of fear.


2015 ◽  
Vol 8 (1) ◽  
pp. 87-108 ◽  
Author(s):  
André de Waal ◽  
Robert Goedegebuure ◽  
Eveline Hinfelaar

Purpose – The importance of partnerships to organizational success has increased considerably the past decennia and many organizations strive at creating high-performance partnerships (HPPs). For this to happen, organizations in the partnerships have to be of high quality and their collaborations should be world-class. Whereas the factors that create high-performance organizations (HPO) are by now reasonably well established, the HPP factors are still unclear. The purpose of this paper is to develop a scale for measuring the factors of importance for creating and maintaining HPPs, and relates these factors to the factors of the HPO framework and to the success of the partnership. Design/methodology/approach – During a literature study ten potential factors of importance for creating and maintaining HPPs were identified. These potential factors were put in a questionnaire, together with the factors that create the HPO and the factor that measures the success of the partnership. This questionnaire was administered to a cable company, which was working on becoming an HPO, and four of its main suppliers. The data were subjected to a factor analysis which yielded a HPP framework consisting of three factors and 19 underlying characteristics. In addition, these HPP factors were put in a regression analysis with the factors of the HPO framework and the success of the partnership factor. Findings – The research results show a strong relationship between three HPP factors, the five HPO factors, and the success of a partnership factor. Research limitations/implications – This research adds to the literature by extending the concept of HPOs to the value chain these HPOs operate in. Thus the research into the factors of successful partnerships has been brought forward. The practical benefit of the research is that organizations can use the HPP factors to increase the quality of the partnerships they have with their suppliers and customers. Originality/value – There is much literature on partnerships but not so much on partnerships between organizations which strive to become a HPOs, and in the process need to create partnership of high quality.


1989 ◽  
Vol 69 (3_suppl) ◽  
pp. 1351-1367 ◽  
Author(s):  
Robert S. Sturgeon ◽  
Leslie M. Cooper ◽  
Robert J. Howell

15 highly aroused snake phobics individually constructed fear hierarchies by selecting colored photographs of snakes. Subjects either imagined fear scenes based on their photographs or were exposed to duplicate projected slides during desensitization. Pupillary responses of the Slide Group were also recorded before, during, and after desensitization. Fear of snakes was significantly reduced for both groups within five or fewer desensitization sessions. Changes in pupil size of the Slide Group appear to reflect arousal of fear as well as reduction of fear after treatment. Current technology makes pupillary response a viable psychophysiological measure of fear.


2020 ◽  
Author(s):  
Yue Zhang ◽  
Alexandre Lehmann ◽  
Mickael Deroche

AbstractRecent research has demonstrated that pupillometry is a robust measure for quantifying listening effort. However, pupillary responses in listening situations where multiple cognitive functions are engaged and sustained over a period of time remain hard to interpret. This limits our conceptualisation and understanding of listening effort in realistic situations, because rarely in everyday life are people challenged by one task at a time. Therefore, the purpose of this experiment was to reveal the dynamics of listening effort in a sustained listening condition using a word repeat and recall task.Words were presented in quiet and speech-shaped noise at different signal-to-noise ratios (SNR). Participants were presented with lists of 10 words, and required to repeat each word after its presentation. At the end of the list, participants either recalled as many words as possible or moved on to the next list. Simultaneously, their pupil dilation was recorded throughout the whole experiment.When only word repeating was required, peak pupil dilation (PPD) was bigger in 0dB versus other conditions; whereas when recall was required, PPD showed no difference among SNR levels and PPD in 0dB was smaller than repeat-only condition. Baseline pupil diameter and PPD followed different growth patterns across the 10 serial positions in conditions requiring recall: baseline pupil diameter built up progressively and plateaued in the later positions (but shot up at the onset of recall, i.e. the end of the list); PPD decreased at a pace quicker than in repeat-only condition.The current findings concur with the recent literature in showing that additional cognitive load during a speech intelligibility task could disturb the well-established relation between pupillary response and listening effort. Both the magnitude and temporal pattern of task-evoked pupillary response differ greatly in complex listening conditions, urging for more listening effort studies in complex and realistic listening situations.


2019 ◽  
Vol 14 (6) ◽  
pp. 591-599 ◽  
Author(s):  
David Pagliaccio ◽  
Daniel S Pine ◽  
Ellen Leibenluft ◽  
O Dal Monte ◽  
Bruno B Averbeck ◽  
...  

Abstract Few studies have used matched affective paradigms to compare humans and non-human primates. In monkeys with amygdala lesions and youth with anxiety disorders, we examined cross-species pupillary responses during a saccade-based, affective attentional capture task. Given evidence of enhanced amygdala function in anxiety, we hypothesized that opposite patterns would emerge in lesioned monkeys and anxious participants. A total of 53 unmedicated youths (27 anxious, 26 healthy) and 8 adult male rhesus monkeys (Macaca mulatta) completed matched behavioral paradigms. Four monkeys received bilateral excitotoxic amygdala lesions and four served as unoperated controls. Compared to healthy youth, anxious youth exhibited increased pupillary constriction in response to emotional and non-emotional distractors (F(1,48) = 6.28, P = 0.02, η2p = 0.12). Pupillary response was associated significantly with anxiety symptoms severity (F(1,48) = 5.59, P = 0.02, η2p = 0.10). As hypothesized, lesioned monkeys exhibited the opposite pattern i.e. decreased pupillary constriction in response to distractors, compared to unoperated control monkeys (F(1,32) = 24.22, P < 0.001, η2 = 0.33). Amygdala lesioned monkeys and youth with anxiety disorders show opposite patterns of pupil constriction in the context of an affective distractor task. Such findings suggest the presence of altered amygdala circuitry functioning in anxiety. Future lesion and human neuroimaging work might examine the way in which specific amygdala sub-nuclei and downstream circuits mediate these effects.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yih-Giun Cherng ◽  
Talia Baird ◽  
Jui-Tai Chen ◽  
Chin-An Wang

Abstract Pupil dilation is consistently evoked by affective and cognitive processing, and this dilation can result from sympathetic activation or parasympathetic inhibition. The relative contributions of the sympathetic and parasympathetic systems on the pupillary response induced by emotion and cognition may be different. Sympathetic and parasympathetic activity is regulated by global luminance level. Higher luminance levels lead to greater activation of the parasympathetic system while lower luminance levels lead to greater activation of the sympathetic system. To understand the contributions of the sympathetic and parasympathetic nervous systems to pupillary responses associated with emotion and saccade preparation, emotional auditory stimuli were presented following the fixation cue whose color indicated instruction to perform a pro- or anti-saccade while varying the background luminance level. Pupil dilation was evoked by emotional auditory stimuli and modulated by arousal level. More importantly, greater pupil dilation was observed with a dark background, compared to a bright background. In contrast, pupil dilation responses associated with saccade preparation were larger with the bright background than the dark background. Together, these results suggest that arousal-induced pupil dilation was mainly mediated by sympathetic activation, but pupil dilation related to saccade preparation was primarily mediated by parasympathetic inhibition.


2017 ◽  
Vol 23 (2) ◽  
pp. 366-380 ◽  
Author(s):  
Ferenc Honbolygó ◽  
Andrea Kóbor ◽  
Valéria Csépe

Objectives: Stress “deafness” is a difficulty in the detection of stress pattern changes of second language (L2) words. This study investigated the influence of cognitive factors and L2 proficiency on the processing of L2 stress. Methodology: Fifty-four native speakers of Hungarian, a language with non-contrastive stress, participated in the study; the participants were categorized as not speaking German or having a proficiency at the intermediate or advanced level. They had to recall sequences with increasing length consisting of German pseudowords that differed in either their phonemes (phoneme task) or stress patterns (stress task). Cognitive factors measured included working memory, phonological awareness and inhibitory control. Data and Analysis: The accuracy data obtained in the sequence recall task was analysed with generalized linear mixed modelling. Two separate analyses were performed to investigate the presence of stress “deafness” and the effect of cognitive factors. Findings: Results showed that the stress task led to lower performance than the phoneme task, irrespective of L2 proficiency. Furthermore, the analysis showed different cognitive factors contributing to the performance in the tasks: in the phoneme task, it was working memory, phonological awareness and inhibitory control, while in the stress task, it was only working memory and phonological awareness but not the inhibitory control. Originality: This is the first study to provide evidence about the cognitive background of the stress “deafness” effect, and to suggest the differential role of inhibitory control in phoneme and stress processing. Implications: These findings demonstrate the robustness of the stress “deafness” effect in a language with non-contrastive stress, provide evidence of the effect being independent of L2 proficiency and suggest that speakers of languages with non-contrastive stress do not have the necessary cognitive basis to form accurate L2 stress representations.


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