Head-Eye Coordination Increases with Age and Varies across Countries
| Autor: | Guillaume Giraudet, Jocelyn Faubert, Frédéric J.A.M. Poirier |
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| Rok vydání: | 2015 |
| Předmět: |
Adult
Male Aging medicine.medical_specialty genetic structures Eye Movements Head (linguistics) Audiology 050105 experimental psychology head-eye coordination 03 medical and health sciences 0302 clinical medicine Ethnicity medicine Humans 0501 psychology and cognitive sciences Balance (ability) 05 social sciences Eye movement Original Articles Middle Aged saccades Gaze eye diseases Visual field Ophthalmology age Head Movements Fixation (visual) Peripheral vision Saccade eye correction Female Psychology Psychomotor Performance 030217 neurology & neurosurgery Optometry |
| Zdroj: | Optometry and Vision Science |
| ISSN: | 1040-5488 |
| Popis: | Saccades made toward eccentric targets (>10 to 15 degrees of eccentricity) are often accompanied by head movements by unrestrained participants. There is considerable individual variability in the amount of head rotation1–3 that remains unexplained by neck or ocular motor range4 or the high ocular accuracy range.5 Effect of Age Head gain is the ratio of head movement to total movement (head + eye) when executing a saccade to an eccentric target. Two studies have investigated the relationship between head gain and age, with conflicting results. The first study by Proudlock et al.6 found that younger participants were primarily eye movers, whereas older participants included both primarily eye movers and eye-and-head movers. The second study by Thumser et al.7 found no correlation of head gain with cognitive functioning measures, and at most a mild reduction of head gain with age. Younger participants included many that made considerable head movements. A possible cause for the discrepancy may be low sample sizes for a comparison between groups in the presence of high individual variability. Effect of Glasses Another issue is whether wearing glasses affects head movements. Again, past studies provide conflicting results. Larger-amplitude head movements have been described in a group of presbyopes when wearing progressive lenses compared with the same subjects wearing single vision lenses.8 Proudlock et al.6 also mentioned a link between wearing glasses and head movements, but that effect disappeared when controlled for various factors including age. The issue is particularly relevant as head gains are affected by paralysis or field-of-view occlusion.9–13 Stahl14 found that restriction of neck movement reduced head gain even after the restriction was removed. Occlusion of field of view increased head gain but only during occlusion11,14; normal head gains returned after removal of occlusion.14 If these results generalize to long-term usage of glasses, which are known to produce a degradation of peripheral vision quality, then head gains could be affected by correction strength. Cultural Effect Cultural differences in gaze and saccade behavior are well documented.15 For example, there are cultural differences in fixation patterns during face tasks,16 in express saccades,17 and in fixation patterns to visual novelty in scenes18–20 (but see Ref. 21). To our knowledge, no previous study investigated whether these biases might generalize to head-eye coordination. The Importance to Balance It has been suggested that the head position plays an important role in equilibrium.22 Possible causes of dizziness and equilibrium problems encountered by older people include (1) reduced vestibular ocular reflexes,23–25 (2) distortions of the visual field produced by glasses,26 and (3) higher head gains. Research Goals The individual variability of eye-head coordination strategy has been used by Essilor for the conception of personalized progressive eyeglass lens27: the Varilux Ipseo. To provide this customized lens, the precise visual strategy of each person is measured by the VisionPrint System (VPS; full description below). Then, lenses are designed to reduce aberrations in accordance with the person’s visual strategy. Since the launch of Varilux Ipseo in 2003, the VPS was used throughout the world in tens of thousands of optician stores. Furthermore, this tool has been extensively used and evaluated in the ESSILOR R&D facilities. The primary goals of this study are (1) to resolve conflicts in past results,6,7 (2) test additional factors that may affect eye-head coordination, and (3) provide an estimate of eye-head coordination for situations where VPS measurement is impractical. This database of 65,115 participants allows for high statistical power even for more detailed analyses. The current study does not include measures of dizziness and equilibrium. Further studies on large samples could include questionnaires to evaluate the prevalence of dizziness and equilibrium problems. The VPS measures head movements in conditions where there are frequent saccades to eccentric targets. This replicates scenarios in which we expect dizziness to be more prevalent. Real-world scenarios requiring frequent saccades to eccentric targets include driving or crossing a street.28 We note, however, that head movement strategies differ greatly in other scenarios,29,30 for example, during manual work where people tend to produce fewer saccades to eccentric locations. |
| Databáze: | OpenAIRE |
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