October 2003
Volume 3, Issue 9
Free
Vision Sciences Society Annual Meeting Abstract  |   October 2003
Infants integrate local motion
Author Affiliations
  • Karen R Dobkins
    Psychology Department, UC San Deigo, USA
Journal of Vision October 2003, Vol.3, 203. doi:10.1167/3.9.203
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Karen R Dobkins, Ione Fine, Annie C Hsueh, Carolin Vitten; Infants integrate local motion. Journal of Vision 2003;3(9):203. doi: 10.1167/3.9.203.

      Download citation file:


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

      ×
  • Supplements
Abstract

PURPOSE: It is not yet clear whether infants integrate component motions into coherent pattern motion. Though infants track moving plaids in the pattern direction (Manny & Fern, 1990), this may be due to tracking the “nodes” of plaid intersections rather than to true integration of the components. Here, we tested infant motion integration using component gratings that were spatially separated, and thus did not contain trackable intersections. METHODS: The control stimulus was a field of evenly spaced moving grating patches (2 ×4 , 0.8 cpd, 80% contrast, 6 /sec). Every patch moved in one of four directions (72 , −72 , 108 or 252 ). The integration stimulus consisted of grating patches, but two directions (72 /−72 or 108 /252 ) were presented in an alternating checkerboard pattern. When integrated, pattern motion for these paired component motions was 0 (right) or 180 (left) at 20 /sec. Using a directional (left vs. right) eye movement technique, we compared infants' ability to track horizontal pattern motion in the integration stimulus to their ability to track the horizontal component of oblique motion in the control stimulus. Integration was computed as the difference in percent correct for integration and control conditions. For integration to occur requires the summation area of integrative motion mechanisms to be relatively large compared to the distribution of the grating patches. RESULTS: Data from 2-, 3-, 4- & 5-month-olds revealed significant integration at all but the oldest age. Integration decreased consistently and significantly with age (17%, 19%, 12% & 2%, p<0.03). Adults did not show significant integration. CONCLUSIONS: By 2 months of age infants integrate local motion signals into coherent global motion. Given that motion integration is subserved by area MT, this suggests that human MT is functional by 2 months of age. The decrease in integration with age implies a reduction in the size of motion summation areas over the course of development.

Dobkins, K. R., Fine, I., Hsueh, A. C., Vitten, C.(2003). Infants integrate local motion [Abstract]. Journal of Vision, 3( 9): 203, 203a, http://journalofvision.org/3/9/203/, doi:10.1167/3.9.203. [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.

×