Differential aging effects in motion perception tasks for central and peripheral vision

Abstract

The perception of motion is considered critical for performing everyday tasks, such as locomotion and driving, and relies on different levels of visual processing. However, it is unclear whether healthy aging differentially affects motion processing at specific levels of processing, or whether performance at central and peripheral spatial eccentricities is altered to the same extent. The aim of this study was to explore the effects of aging on hierarchically different components of motion processing: the minimum displacement of dots to perceive motion (D min ), the minimum contrast and speed to determine the direction of motion, spatial surround suppression of motion, global motion coherence (translational and radial), and biological motion. We measured motion perception in both central vision and at 15° eccentricity, comparing performance in 20 older (60–79 years) and 20 younger (19–34 years) adults. Older adults had significantly elevated thresholds, relative to younger adults, for motion contrast, speed, D min , and biological motion. The differences between younger and older participants were of similar magnitude in central and peripheral vision, except for surround suppression of motion, which was weaker in central vision for the older group, but stronger in the periphery. Our findings demonstrate that the effects of aging are not uniform across all motion tasks. Whereas the performance of some tasks in the periphery can be predicted from the results in central vision, the effects of age on surround suppression of motion shows markedly different characteristics between central and peripheral vision.

Motion perception at mesopic light levels: effects of physiological ageing and eccentricity

“…In our data analysis we explored three‐way interactions (light condition, age and eccentricity), two‐way interactions (light condition and eccentricity; light condition and age, and age and eccentricity) and the main effect of light levels. We transformed raw values into log values to allow the use of parametric statistical tests and also to be consistent in terms of units with our previously published work 30 . For the analysis, the level of statistical significance was p < 0.05 unless specified otherwise.…”

“…At each session, four motion perception tasks of different complexities were assessed binocularly in central vision (centre of the stimulus located at 0° eccentricity) and peripheral vision (stimulus centre located at 15° to the right and 5° upwards from the screen centre). The stimulus location was selected to be consistent with our previous study, 30 with the upwards shift of the stimulus allowing the physiological blind spot to be avoided in one eye. These tasks were the following:…”

“…Under photopic conditions, age‐related differences in motion perception have been shown to depend on the nature of the motion task, 27‐31 with some complex motion tasks (such as global motion coherence) being less affected by the effects of healthy ageing 30,31 . As mentioned earlier, in central vision, contrast sensitivity at low light levels is reduced in older compared to younger adults 4 .…”

Age-related decline in motion contrast sensitivity due to lower absorption rate of cones and calculation efficiency

“…Motion perception is essential for many daily activities such as walking in a crowded environment, practicing a sport, crossing a street and driving. However, motion perception decline with healthy aging 1 – 5 , which can reduce the ability of older adults to perform efficiently and safely many daily activities. For instance, motion perception is obviously essential for driving and older adults were found to be less sensitive to changes of vehicle velocities 6 , have difficulties judging vehicle trajectories 7 and miss judging upcoming collision events 8 , which affects their ability to drive safely.…”

“…A measure of motion perception is motion contrast sensitivity, which is affected with aging at all temporal frequencies in central vision 1 , 2 , 5 , 12 . Although many studies show that healthy aging affects motion contrast sensitivity, the underlying causes for age-related motion contrast sensitivity loss is still debated in the literature.…”