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Blinking and Looking: An Eye-Tracking Approach to Studying Cognitive Processing Differences in Individuals with Speech, Language, and Communication Disorders
Published in Stavros Hatzopoulos, Andrea Ciorba, Mark Krumm, Advances in Audiology and Hearing Science, 2020
Jennifer M. Roche, Schea N. Fissel
Pupillometry is fully non-volitional and involves measurement of pupil diameter (see Fig. 4.3 for an example). Similar to endogenous blinking behavior, increased pupil dilation allows the eyes to receive more visual input. However, pupil dilation, and this measure, are thought to reflect processing load relative to decision making. Pupil dilation is not always attached to visual stimulus processing; there have been results linking pupil dilation to auditory processing load. For instance, Engelhardt et al. (2009) found that when listeners heard prosodic variation (e.g., tone of voice) that conflicted with the sentence semantics, pupil diameter increased. Zekveldet al. (2011) also found larger pupil diameters in aging individuals with hearing loss when they processed speech in noise, indicating an increase in perceptual demands required for perceptual speech processing. Pupil dilation is a highly sensitive measure and requires careful consideration and planning for valid measurement. Pupil dilation is very sensitive to illumination of visual stimuli, general lighting features of the environment (luminescence), as well as carry-over effects from previously shown/seen visual stimuli; it is very important for researchers to control the visual environment when collecting pupillometry data. Stable fixations (>300 ms) on a researcher-defined AOI are also required to achieve accurate measurements of pupil dilation.
Multiple Sleep Latency Test
Published in Clete A. Kushida, Sleep Deprivation, 2004
Lamia Afifi, Clete A. Kushida, Mary A. Carskadon
In the 1960s, the Mayo Clinic group had used pupillometry (8) as an objective measure of sleepiness; however, this technique did not achieve widespread use owing to its limitation by ocular or autonomic lesions, dependence on the patient’s cooperation, and difficulties in data interpretation. In the early 1970s, the Stanford group, perceiving the difficulties associated with pupillometry, began by first developing the Stanford Sleepiness Scale and later developing the MSLT. The MSLT arose directly from the results of the 90-min day experiments (9). Most important was the identification during the 90-min day study that the amount of the 30-min night filled with sleep, which was nearly 100%, correlated to the speed of falling asleep, varied across the 24 hr, and was associated with the temporal distribution of sleep and feelings of sleepiness. During the same era, the study of sleep deprivation was of growing scientific interest. The work of the Walter Reed group and the San Diego Naval Research Lab, as well as international efforts, were poised to carry the understanding of sleep deprivation and its impact to the next level. These experiments utilized measures of performance and a variety of self-report measures to evaluate the response of subjects to various sleep deprivation and sleep restriction paradigms. Others have gone on to identify other performance parameters that may be relative to sleep deprivation; however, the key behavioral outcome, that is, sleepiness or sleep tendency, remained a secondary focus and was not always well discriminated.
Trigeminal autonomic cephalgias II-(paroxysmal hemicranla and SUNCT) and other short-lasting headache (hypnic headache)
Published in Stephen D. Silberstein, Richard B. Upton, Peter J. Goadsby, Headache in Clinical Practice, 2018
Stephen D. Silberstein, Richard B. Upton, Peter J. Goadsby
Orbital phlebography is reported to be abnormal in patients with SUNCT, with a narrowed superior ophthalmic vein homolateral to the pain.116 This finding led to the suggestion that SUNCT may be a form of orbital venous vasculitis,117 although there are similar reports in cluster headache, Tolosa-Hunt syndrome, and PH (see above). Forehead sweating, which is normal in CPH, is usually increased during bouts of SUNCT.118 Pupillometry and pharmacological approaches have revealed no abnormalities.119 Since conjunctival injection occurs during SUNCT, it is not surprising that intraocular pressure and comeal temperatures are elevated during attacks.120 This most likely reflects marked parasympathetic activation with local vasodilation. Bradycardia in association with attacks of SUNCT121 may similarly indicate increased parasympathetic outflow. Systolic blood pressure is sometimes elevated,122 although ventilatory function is normal.123 The parasympathetic manifestations favor a central pathogenesis for SUNCT as a manifestation of the trigeminovascular reflex,124 rather than a peripheral vasculitic cause. Transcranial Doppler and single-photon emission computed tomography (SPECT) studies have not demonstrated convincing changes in the vasomotor activity125 or cerebral blood flow126 during attacks of pain. One patient who experienced multiple attacks that could be averaged to identify significant areas of brain activation was studied using functional MRI (fMRI). The pattern seen was increased posterior hypothalamic blood flow114 in a region very similar to that identified in patients with acute cluster headache (Figure 10.2).115
Evaluation of Pupillometric Parameters in Patients with COVID-19
Published in Ocular Immunology and Inflammation, 2023
Yücel Öztürk, Merve Beyza Yıldız, Rüveyde Bolaç
The autonomic nervous system affects multiple ocular functions, including pupillary reflexes. Mydriasis and miosis occur in response to sympathetic and parasympathetic stimulation, respectively. The afferent pathway of the pupillary light reflex is carried by the second cranial nerve, while the efferent pathway is carried by the third cranial nerve.12 Pupillometry analysis provides useful information in the diagnosis and follow-up of many neurological and ophthalmological diseases.13 The identification of the differentiation in autonomic nervous system function presented by pupillometric measurements may contribute to the understanding of the neurological effects of COVID-19 and may become a useful clinical biomarker to detect autonomic nervous system differences. We aimed to investigate the pupil diameter and the pupillary light response in patients with a history of COVID-19 accompanied by neurological manifestations compared with the age- and gender-matched healthy controls.
Pupillometry as a measure for listening effort in children: a review
Published in Hearing, Balance and Communication, 2020
N. Gómez-Merino, F. Gheller, G. Spicciarelli, P. Trevisi
Pupillometry is the measurement of the pupil size and its changes when triggered by stimuli of various kinds. The eye tracker is the device specifically used to assess the pupil diameter: it provides both temporal resolution and accurate measurement, managing to detect even small changes. This non-invasive tool uses near-infrared technology with a high-resolution camera to record eye-movement data, such as gaze direction. Near-infrared light is directed towards the pupil causing reflections in the cornea that are tracked by the camera. Specific algorithms are used to determine exactly the eye’s position and the gaze direction, and to estimate the diameter of the pupil. There are two main types of eye tracker: static (e.g. screen-based eye-trackers) and head-mounted eye-trackers (e.g. glasses).
Future Research Directions for the Trophoblast Model of Cancer
Published in Nutrition and Cancer, 2018
Subsequently, or simultaneously with Step 1, research could be conducted to develop one or more objective physiological measures of autonomic type. A candidate procedure is pupillometry, which is the measurement of pupil size. The equipment required is affordable and practical. Pupillometry is a well-validated procedure and has been used in psychiatric research, where it is combined with psychological challenges such as fear scripts, alarming videos, and other techniques designed to activate a fight-flight response (31–34). In response to such challenges, some individuals exhibit dilation of the pupils, and some do not. Pupil dilation is part of sympathetic threat response physiology, whereas constriction is characteristic of a parasympathetic response. The prediction for this line of research is that pupil response will vary with autonomic type along the continuum from sympathetic to parasympathetic-dominant.