Psychophysical estimation of speed discrimination II Aging effects

Abstract

We studied the effects of aging on a speed discrimination task using a pair of first-order drifting luminance gratings. Two reference speeds of 2 and 8 deg/s were presented at stimulus durations of 500 ms and 1000 ms. The choice of stimulus parameters, etc., was determined in preliminary experiments and described in Part I. Thresholds were estimated using a two-alternative-forced-choice staircase methodology. Data were collected from 16 younger subjects (mean age 24 years) and 17 older subjects (mean age 71 years). Results showed that thresholds for speed discrimination were higher for the older age group. This was especially true at stimulus duration of 500 ms for both slower and faster speeds. This could be attributed to differences in temporal integration of speed with age. Visual acuity and contrast sensitivity were not statistically observed to mediate age differences in the speed discrimination thresholds. Gender differences were observed in the older age group, with older women having higher thresholds.

Aging and the discrimination of 3-D shape from motion and binocular disparity

“…Older adults often have difficulty performing any task involving motion, even if it does not concern shape. For example, older adults' ability to discriminate the speed of moving patterns is much worse than younger adults' (e.g., Norman, Burton, & Best, 2010;Norman, Ross, Hawkes, & Long, 2003;Raghuram, Lakshminarayanan, & Khanna, 2005;Snowden & Kavanagh, 2006). Our present finding that the age-related deficit for discriminations of 3-D shape is higher for motion than for static binocular disparity is consistent with the idea that aging negatively affects performance on most, if not all, psychophysical tasks involving motion (see also Atchley & Andersen, 1998;Bennett, Sekuler, & Sekuler, 2007;Betts, Taylor, Sekuler, & Bennett, 2005).…”

Aging and vision

“…Since this report 25 years ago, many studies have probed motion-processing deficits in the elderly. For example, elevations in both detection and discrimination thresholds in a variety of motion tasks have been documented for older adults suggesting a reduced sensitivity to motion and impaired abilities to identify the direction of movement and differentiate differences in speed (Anderson & Atchley, 1995; Atchley & Anderson, 1998; Norman, Ross, Hawkes & Long, 2003; Raghuram, Lakshminarayanan & Khanna, 2005; Snowden & Kavanagh, 2006; Tran, Silverman, Zimmerman & Feldon, 1998; Trick & Silverman, 1991). There is preliminary evidence that these deficits do not appear gradually during the course of adulthood, but rather, may emerge in late adulthood around the 70s (Bennett, Sekuler & Sekuler, 2007).…”

“…There is preliminary evidence that these deficits do not appear gradually during the course of adulthood, but rather, may emerge in late adulthood around the 70s (Bennett, Sekuler & Sekuler, 2007). Furthermore, increasing the duration of the stimulus allows some older adults to improve their performance to the level of young adults (Bennett et al, 2007; Raghuram et al, 2005), which suggests that extending viewing time for older adults in a real-world performance task dependent on motion processing may at least partly compensate for deficits.…”

Altered cortical spectrotemporal processing with age-related hearing loss

“…Therefore, it is interesting to note that neurons in aging macaque monkey area middle temporal (MT) also prefer slower motion speeds and show increased response variability to repetitions of motion stimuli (Yang et al 2009b). Moreover, analogous to results with time expansion of consonants in audition, thresholds for detecting visual motion speed improve with increasing stimulus duration to a larger extent in older participants (Raghuram et al 2005). Similar receptive field mechanisms have been proposed to underlie FM rate selectivity and motion speed selectivity in auditory Fuzessery 2008, 2009;Trujillo et al 2013) and visual (Duysens et al 1985;Razak and Pallas 2005) systems, respectively.…”