August 2023
Volume 23, Issue 9
Open Access
Vision Sciences Society Annual Meeting Abstract  |   August 2023
Looking for details: Fine-grained visual search at foveal scale
Author Affiliations & Notes
  • Sanjana Kapisthalam
    University of Rochester
  • Martina Poletti
    University of Rochester
  • Footnotes
    Acknowledgements  Funded by Meta, Inc
Journal of Vision August 2023, Vol.23, 4959. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Sanjana Kapisthalam, Martina Poletti; Looking for details: Fine-grained visual search at foveal scale. Journal of Vision 2023;23(9):4959.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

The concept of visual search is normally associated with large saccades, which are used to place the high-resolution fovea on the stimuli of interest. Yet, during fixation, fine spatial detail at the center of gaze is actively sampled through microsaccades. Using high-resolution eye-tracking coupled with a gaze-contingent display control system, enabling localization of the line of sight with arcminute precision, we investigated if the visuomotor system can engage in visual search at a finer scale during fixation. Subjects (n=9) were instructed to localize a target (a tilted bar: 1x8 arcminutes in size) in an array of 7 similar items. The stimulus array, presented for 1s, spanned 0.5 degrees, approximately half the size of the foveola. Salience was modulated by changing the color of the stimuli, whereas task relevance was modulated by changing their degree of tilt. Despite stimuli being presented foveally, our results show that subjects did not maintain fixation at the center of the stimulus array, but engaged in active visual search, using microsaccades as small as 10 arcminutes. Microsaccades benefited performance; in the absence of microsaccades the probability of correctly localizing the target dropped by 10% (p=0.01). Perceptual saliency influenced microsaccades, which were more precise and their latency was 120ms faster in the presence of a salient target. However, when the distractor was salient, microsaccades towards the distractor were actively suppressed. Microsaccade precision was also influenced by the task-relevance of distractors; when the distractors’ orientation was similar to that of the target the probability of microsaccades landing on the target dropped (0.55 vs 0.25; p=0.01). These findings suggest that the visuomotor system can engage in a fine-grained visual search and is capable of establishing high-resolution priority maps of the foveal space based on the relevance and salience of individual details.


This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.