June 2004
Volume 4, Issue 8
Free
Vision Sciences Society Annual Meeting Abstract  |   August 2004
Categorizing attentional loss in hemineglect with classification images
Author Affiliations
  • Steven S. Shimozaki
    University of California, Santa Barbara, USA
  • Miguel P. Eckstein
    University of California, Santa Barbara, USA
  • Bettina Olk
    University of British Columbia, Canada
  • Alan Kingstone
    University of British Columbia, Canada
Journal of Vision August 2004, Vol.4, 453. doi:10.1167/4.8.453
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Steven S. Shimozaki, Miguel P. Eckstein, Bettina Olk, Alan Kingstone; Categorizing attentional loss in hemineglect with classification images. Journal of Vision 2004;4(8):453. doi: 10.1167/4.8.453.

      Download citation file:


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

      ×
  • Supplements
Abstract

Hemineglect describes patients with unilateral brain damage that tend to ignore the contralesional visual field. While neglect most commonly occurs with parietal lesions, damage to other areas may also cause neglect (see Karnath, Milner, & Vallar, 2002), possibly by different mechanisms. To identify potentially different causes of neglect, the perceptual templates in a cueing task were estimated for three normal observers and two male right-hemisphere lesioned patients (with previous histories of hemineglect) by correlating observers' responses with the image noise leading to those responses (‘classification images’). Observers performed a yes/no contrast discrimination of a signal appearing at one of two locations (2.5 deg left and right from center). Prior to the stimulus (140 ms), a peripheral precue (140 ms) indicated the signal location with 80% validity. The signal was a 3×3 ‘white X’ checkerboard (1.5 deg), with Gaussian image noise added to each of the 9 checkerboard squares. As expected, the cueing effects and classification images for the normal observers showed no hemispheric differences. As predicted from other studies of hemineglect (e.g., Posner, et al., 1984), the patients (CM, age 85; HL, age 69) had larger cueing effects with right-sided cues (contralesional invalid), compared to left-sided cues (contralesional valid). For CM, the contralesional classification images were positively correlated with the signal with contralesional cues, and negatively correlated with the signal with ipsilesional cues, indicating a severely suboptimal attentional system. For HL, the contralesional classification images were uncorrelated with the signal, regardless of the cue side. HL did not appear to utilize contralesional information, consistent with either a residual visual (hemianopia) or attentional sensitivity loss. In conclusion, classification images successfully distinguished between two different mechanisms of neglect within these two patients.

Shimozaki, S. S., Eckstein, M. P., Olk, B., Kingstone, A.(2004). Categorizing attentional loss in hemineglect with classification images [Abstract]. Journal of Vision, 4( 8): 453, 453a, http://journalofvision.org/4/8/453/, doi:10.1167/4.8.453. [CrossRef]
Footnotes
 Supported by NSF-0135118, NIH-53455, and NASA NAG-1157
×
×

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.

×