The effect of aging on the eccentricity dependency of orientation anisotropy of perceptual surround suppression

Abstract

The features of perceptual surround suppression vary with eccentricity, such that the suppression strength is increased for horizontally oriented stimuli relative to other orientations near the fovea, but is strongest for radially oriented stimuli more peripherally. Perceptual suppression also varies with age, which has been well-studied for central fixation. However, only limited data are available regarding perceptual suppression in older adults for nonfoveal vision, and none of those studies have taken orientation biases of contrast sensitivity into account. Here, we explored the effects of older age on the eccentricity dependency of orientation biases of perceptual suppression. We found increased perceptual suppression in older adults at both 6°and 15°e ccentricities relative to younger adults. A main effect of the horizontal orientation bias was found at 6°and a main effect of the radial orientation bias was found at 15°in both groups. In summary, perceptual surround suppression of contrast is stronger for older adults compared with younger adults at 6°and 15°e ccentricities, but retinotopic orientation anisotropies are maintained with age. This study provides new insight into parafoveal visual perception in older adults, which may be particularly important to understand the visual experience of those who depend on nonfoveal vision owing to common age-related eye diseases.

Radial Bias Alters Perceived Object Orientation

“…Overall, the strength of this bias may depend on other factors that may change the amount of uncertainty in the stimulus representation, such as eccentricity (e.g., Malavita et al, 2021; Raemaekers et al, 2009; Rovamo et al, 1982), stimulus contrast, distribution of presented orientations, and (potentially) participant strategy, all of which may be explored by future researchers. Also, note that our sample consisted of university undergraduates with normal or corrected-to-normal vision, which may limit the generalizability of the findings.…”

Ageing elevates peripheral spatial suppression of motion regardless of divided attention

“…45 We have recently explored perceptual centre-surround contrast suppression in older and younger adults to explore for differences in orientation anisotropies at 6 degrees and 15 degrees eccentricity. 46 Both groups showed stronger suppression for stimuli that were oriented cardinally at 6 degrees, and radially at 15 degrees, relative to other orientation pairings. Similar to our current experiment, older adults showed stronger suppressive effects that younger adults at these non-foveal eccentricities, however no differences in orientation biases were found between groups.…”

“…Similar to our current experiment, older adults showed stronger suppressive effects that younger adults at these non-foveal eccentricities, however no differences in orientation biases were found between groups. 46 Dividing attention resulted in elevated duration thresholds overall but did not change motion suppression indices. Our study was partially motivated by a previous observation that dividing attention paradoxically resulted in an improvement in sensitivity to motion cues encoded in random dot kinematograms.…”