Pupil light reflex evoked by light-emitting diode and computer screen: Methodology and association with need for recovery in daily life

Abstract

ObjectivesPupil light reflex (PLR) has been widely used as a method for evaluating parasympathetic activity. The first aim of the present study is to develop a PLR measurement using a computer screen set-up and compare its results with the PLR generated by a more conventional setup using light-emitting diode (LED). The parasympathetic nervous system, which is known to control the ‘rest and digest’ response of the human body, is considered to be associated with daily life fatigue. However, only few studies have attempted to test the relationship between self-reported daily fatigue and physiological measurement of the parasympathetic nervous system. Therefore, the second aim of this study was to investigate the relationship between daily-life fatigue, assessed using the Need for Recovery scale, and parasympathetic activity, as indicated by the PLR parameters.DesignA pilot study was conducted first to develop a PLR measurement set-up using a computer screen. PLRs evoked by light stimuli with different characteristics were recorded to confirm the influence of light intensity, flash duration, and color on the PLRs evoked by the system. In the subsequent experimental study, we recorded the PLR of 25 adult participants to light flashes generated by the screen set-up as well as by a conventional LED set-up. PLR parameters relating to parasympathetic and sympathetic activity were calculated from the pupil responses. We tested the split-half reliability across two consecutive blocks of trials, and the relationships between the parameters of PLRs evoked by the two set-ups. Participants rated their need for recovery prior to the PLR recordings.ResultsPLR parameters acquired in the screen and LED set-ups showed good reliability for amplitude related parameters. The PLRs evoked by both set-ups were consistent, but showed systematic differences in absolute values of all parameters. Additionally, higher need for recovery was associated with faster and larger constriction of the PLR.ConclusionsThis study assessed the PLR generated by a computer screen and the PLR generated by a LED. The good reliability within set-ups and the consistency between the PLRs evoked by the set-ups indicate that both systems provides a valid way to evoke the PLR. A higher need for recovery was associated with faster and larger constricting PLRs, suggesting increased levels of parasympathetic nervous system activity in people experiencing higher levels of need for recovery on a daily basis.

Best Practices and Advice for Using Pupillometry to Measure Listening Effort: An Introduction for Those Who Want to Get Started

“…Task-induced fatigue might be reflected in the baseline value of the pupillary response over the course of the experiment (i.e., lower baseline toward the end of the experiments). Chronic fatigue (need for recovery) effects the pupillary response as well (see Wang et al., 2018 ).…”

“…Brighter luminance produces more reliable dilations than dark settings ( Steinhauer et al., 2004 ; Wang et al., 2018 ) but take caution that too-bright lighting (especially projected directly at a participant from a computer screen) might also cause discomfort and high number of blinks. A moderate mid-range gray color background on a computer monitor or a plainly lit wall target avoids these issues of discomfort.…”

“…This important concept will return numerous times in this article, especially as it relates to fatigue and capacity. If a person is overly fatigued, there is increased likelihood that effort will be reduced because of less engagement—leading to reduced pupil size ( Wang, Zekveld, Lunner, & Kramer, 2018 ). For the purpose of interpreting pupil size data, this means that the experimenter should be cognizant of whether changes in pupil dilation are truly indicative of changes in task-related effort or unintended participant fatigue or disengagement.…”

Towards systematic and objective evaluation of police officer performance in stressful situations

“…Emotions of fear or anxiety are connected to the stress response but likely stem from conscious working memory circuitry (LeDoux & Pine, 2016). The stress response has certain physiological effects on our central and peripheral nervous systems, affecting our neurological systems to various degrees depending primarily on the kind of threat and how severe it is perceived to be (LeDoux, 2000;Wang et al, 2018). Physiologically, stress can manifest itself as dilated pupils and bronchial tubes, increased heart rate, breathing, blood pressure, muscle strength and awareness, etc.…”

Pupillary Light Reflex in Children with ADHD

“…ADHD and autonomic nervous system The autonomic nervous system (ANS) is a part of the peripheral nervous system that independently regulates body functions such as the heart rate, digestion, respiratory rate, pupillary response, urination, sweating and sexual arousal (17). ANS plays an important role in human body because it regulates internal environment and also chain of physiological events for the purpose of adaptation an organism to environmental changes (18). The ANS consists of visceral afferent pathways, central nervous system integrating complex, as well as sympathetic and parasympathetic efferent pathways (19).…”