August 2010
Volume 10, Issue 7
Free
Vision Sciences Society Annual Meeting Abstract  |   August 2010
Characteristics of dichoptic lateral masking of contrast detection
Author Affiliations
  • Erwin Wong
    Graduate Program in Vision Science, College of Optometry, University of Missouri - St. Louis
Journal of Vision August 2010, Vol.10, 1368. doi:10.1167/10.7.1368
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Erwin Wong; Characteristics of dichoptic lateral masking of contrast detection. Journal of Vision 2010;10(7):1368. doi: 10.1167/10.7.1368.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose. Past studies show strong effects by flanks on contrast detection. A limited dichoptic study showed no net flank effect (Huang et al., 2006). Here we more extensively investigate dichoptic lateral masking. Methods. Observers: 5 adults with normal vision and 2 non-binocular, non-amblyopic (NBNA) adults. Measure: contrast detection threshold (CDT) for a sinusoid (3 c/deg, 2° diameter, vertical) in isolation and with two flanking sinusoids at 3 separations (edge to edge 0.5° overlap, abutting, 0.5° separation). Flanks: target sinusoid (normalized 1.5x and 3x flank CDT) oriented vertical or horizontal, or Gaussian blobs (2° diameter) normalized by the flank CDT. Presentations: target to dominant eye, flanks monoptic (abutting only) or dichoptic (3 separations), 2-AFC with the MOCS, and mirror haploscope with septum. Results. For the normal observers, monoptic viewing produced facilitation by collinear flanks (mean 10%±4% (95% CI)), no effect from orthogonal, and suppression by blobs (8%±6%). These effects were greater for 3x CDT flanks and this difference was not shown under dichoptic viewing. For dichoptic viewing, the overlap condition produced facilitation by collinear flanks (7%±4%), suppression by orthogonal (4%±4%), and no effect by blobs. The abutting condition produced facilitation by collinear flanks (8%±4%) and orthogonal (7%±5%), and no effect by blobs. The separation condition produced suppression by collinear flanks (9%±5%), orthogonal (6%±3%), and blobs (8%±4%). For the NBNA observers, under monoptic and dichoptic viewing all separations showed suppression by collinear flanks (14%±7%), orthogonal (10%±8%) and blobs (8±4%). Conclusions. Dichoptic integration of contrast across space is similar to the known monocular mechanism: facilitation by flanks slightly overlapping or abutting the target, and masking only via spatial channels (blobs had little effect). However, an exclusive dichoptic mechanism is suggested: flanks suppress rather than have no effect when separated from the target. Dichoptic integration is further supported by the suppression shown by the NBNA observers.

Wong, E. (2010). Characteristics of dichoptic lateral masking of contrast detection [Abstract]. Journal of Vision, 10(7):1368, 1368a, http://www.journalofvision.org/content/10/7/1368, doi:10.1167/10.7.1368. [CrossRef]
×
×

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.

×