August 2014
Volume 14, Issue 10
Free
Vision Sciences Society Annual Meeting Abstract  |   August 2014
Foveal input is not required for ensemble coding of emotional faces
Author Affiliations
  • Katherine Wood
    University of California Berkeley
  • Benjamin Wolfe
    University of California Berkeley
  • Anna Kosovicheva
    University of California Berkeley
  • Allison Yamanashi Leib
    University of California Berkeley
  • David Whitney
    University of California Berkeley
Journal of Vision August 2014, Vol.14, 883. doi:10.1167/14.10.883
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Katherine Wood, Benjamin Wolfe, Anna Kosovicheva, Allison Yamanashi Leib, David Whitney; Foveal input is not required for ensemble coding of emotional faces. Journal of Vision 2014;14(10):883. doi: 10.1167/14.10.883.

      Download citation file:


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

      ×
  • Supplements
Abstract

Observers can reliably perceive the average of an ensemble of stimuli (Watamaniuk et.al, 1992; Dakin et.al, 1997; Chong and Treisman, 2001), including high-level stimuli such as faces (Haberman and Whitney, 2007). However, it has been suggested that ensemble coding is simply averaging of foveal information over successive saccades. To test this, we performed a study in which subjects viewed sets of 24 faces with and without foveal information available. Face stimuli were selected from a set of 147 morphs, with expressions ranging from happy to sad to angry. After 1500 ms of free viewing, subjects were asked to report the mean expression of the ensemble. In one condition, subjects had their view of the array of faces unobstructed; in a critical second condition, a gaze-contingent circular occluder (2.6° in diameter) completely blocked foveal information. Subjects performed equally well across the occluded and non-occluded conditions, with no significant difference in response error. Additionally, when foveal information was occluded, subjects spent significantly more time fixating between faces in the ensemble (rather than directly on a face) compared to the unobstructed condition. In a follow-up experiment, we varied the proportion of faces that were visible in the set; we found that subjects' performance improved as more faces were presented, regardless of the foveal stimulation, indicating that they were integrating information from multiple faces in the display under both non-occluded and occluded conditions. Thus, while subjects adopted different fixation patterns between conditions, opting to fixate off of a face more in the occluded condition, performance on the task was unaffected by the loss of foveal information. This indicates that ensemble perception of faces is not determined solely by foveal input, but can operate entirely on information in the peripheral visual field.

Meeting abstract presented at VSS 2014

×
×

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.

×