Eye movements, visual search and scene memory, in an immersive virtual environment.
Visual memory has been demonstrated to play a role in both visual search and attentional prioritization in natural scenes. However, it has been studied predominantly in experimental paradigms using multiple two-dimensional images. Natural experience, however, entails prolonged immersion in a limited number of three-dimensional environments. The goal of the present experiment was to recreate circumstances comparable to natural visual experience in order to evaluate the role of scene memory in guiding eye movements in a natural environment. Subjects performed a continuous visual-search task within an immersive virtual-reality environment over three days. We found that, similar to two-dimensional contexts, viewers rapidly learn the location of objects in the environment over time, and use spatial memory to guide search. Incidental fixations did not provide obvious benefit to subsequent search, suggesting that semantic contextual cues may often be just as efficient, or that many incidentally fixated items are not held in memory in the absence of a specific task. On the third day of the experience in the environment, previous search items changed in color. These items were fixated upon with increased probability relative to control objects, suggesting that memory-guided prioritization (or Surprise) may be a robust mechanisms for attracting gaze to novel features of natural environments, in addition to task factors and simple spatial saliency.
Computer Science Department, University of Bath, Bath, United Kingdom.
Dmitry
D
Kit
Institute for Neuroscience, Center for Perceptual Systems, University of Texas, Austin, Texas, United States of America.
Leor
L
Katz
Smith Kettlewell Eye Research Institute, San Francisco, California, United States of America.
Brian
B
Sullivan
Psychology Department, Center for Perceptual Systems, University of Texas, Austin, Texas, United States of America.
Kat
K
Snyder
Computer Science Department, Center for Perceptual Systems, University of Texas, Austin, Texas, United States of America.
Dana
D
Ballard
Psychology Department, Center for Perceptual Systems, University of Texas, Austin, Texas, United States of America.
Mary
M
Hayhoe
D005133:Eye Movements / Q000502:physiology*; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D010364:Pattern Recognition, Visual / Q000502:physiology