Spatial asymmetries ("pseudoneglect") in free visual exploration-modulation of age and relationship to line bisection

Exp Brain Res. 2021 Sep;239(9):2693-2700. doi: 10.1007/s00221-021-06165-x. Epub 2021 Jul 4.

Abstract

When humans visually explore an image, they typically tend to start exploring its left side. This phenomenon, so-called pseudoneglect, is well known, but its time-course has only sparsely been studied. Furthermore, it is unclear whether age influences pseudoneglect, and the relationship between visuo-spatial attentional asymmetries in a free visual exploration task and a classical line bisection task has not been established. To address these questions, 60 healthy participants, aged between 22 and 86, were assessed by means of a free visual exploration task with a series of naturalistic, colour photographs of everyday scenes, while their gaze was recorded by means of a contact-free eye-tracking system. Furthermore, a classical line bisection task was administered, and information concerning handedness and subjective alertness during the experiment was obtained. The results revealed a time-sensitive window during visual exploration, between 260 and 960 ms, in which age was a significant predictor of the leftward bias in gaze position, i.e., of pseudoneglect. Moreover, pseudoneglect as assessed by the line bisection task correlated with the average gaze position throughout a time-window of 300-1490 ms during the visual exploration task. These results suggest that age influences visual exploration and pseudoneglect in a time-sensitive fashion, and that the degree of pseudoneglect in the line bisection task correlates with the average gaze position during visual exploration in a time-sensitive manner.

Keywords: Eye movements; Line bisection; Pseudoneglect; Visual exploration.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Attention
  • Bias
  • Functional Laterality
  • Humans
  • Middle Aged
  • Space Perception*
  • Time Perception*
  • Young Adult