Go to the NASA Homepage
 
Search >
Click to Search
Human Systems Integration Division homepageHuman Systems Integration Division homepage Organization pageOrganization page Technical Areas pageTechnical Areas page Outreach and Publications pageOutreach and Publications page Contact pageContact page
Human Systems Integration Division Homepage
Outreach & Publications Sidebar Header
Go to the Outreach & Publications pageGo to the Outreach & Publications page
Go to Awards pageGo to Awards page
Go to News pageGo to News page
Go to Factsheets pageGo to Factsheets page
Go to Multimedia pageGo to Multimedia page
Go to Human Factors 101 pageGo to Human Factors 101 page
What is Human System Integration? Website
Publication Header
Motion-contrast sensitivity: Visibility of motion gradients of various spatial frequencies  (1994)
Abstract Header
The purpose of these experiments was to estimate basic sensitivity to motion gradients, and to evaluate the evidence for second-order integration and differentiation of motion signals. We measured sensitivity to spatially sinusoidal contrast modulation between two oppositely-moving bandpass-filtered noise images. The motion-contrast sensitivity function, defined as the inverse of threshold modulation amplitude as a function of modulation spatial frequency, was band-pass in shape with declines at both highest and lowest frequencies. The functions for three noise spatial frequencies were approximately the same shape when modulation frequency was expressed as a fraction of the noise frequency. We compared the data to a model in which linear motion filters, whose outputs are squared or rectified, are followed by a second stage of excitatory and/or inhibitory pooling. The data are consistent with a model in which 1) all excitatory pooling occurs at the linear stage, and 2) the second stage contains a large inhibitory pooling area, with a radius about 8 times that of the linear receptive field.
Private Investigators Header
Authors Header
Groups Header
Keywords Header
frequencies, gradients, motion, Motion-contrast, sensitivity, spatial, Visibility
References Header
Journal of the Optical Society of America A 11(2), 496-505
Download Header
Adobe PDF Icon  Watson_motioncontrast.pdf (Download Acrobat Reader Click to download Adobe Acrabat Reader)
  (377KB) (application/pdf)
Go to the First Gov Homepage
Go to the NASA - National Aeronautics and Space Administration Homepage
Curator: Phil So
NASA Official: Alonso Vera
Last Updated: August 15, 2019