The Spatiotemporal Characteristics of Visual Motion Priming
Abstract
A motion signal that is produced from a sine-wave luminance grating which has undergone an abrupt 90-degree phase shift (frames 1 to 2) can serve as a priming signal that disambiguates motion of a second, 180-degree (counterphase) shift (frames 2 to 3). Four experiments investigated the spatiotemporal characteristics of this phenomenon which is termed visual motion priming (VMP). Experiment 1 varied the phase-shift magnitude of the priming signal from 22.5 through 157.5 degrees. This resulted in an inverted U-shaped half-sine function that peaked at 90 degrees with 93.5% priming. Experiment 2 varied frame 2 duration (192, 384, 768, and 1530 ms), spatial frequency (0.7, 1. 4, and 2.8 cycles/degree), and used 19 or 48% contrast for the 3 frames. VMP decreased monotonically from about 94% at 192 ms to near 50% (chance level) at 768 and 1530 ms. Duration and spatial frequency were significant, but contrast had no systematic effect. Experiment 3 varied the ratio of frame 1 contrast (4, 6, 13, 19, 30, 48%) relative to frames 2 and 3, where both of the latter two frames had either 19 or 48% contrast. Several effects were observed. When the ratio of the contrasts between frames 1 and 2 was largest (4-48-48% contrast for frames 1-2-3, respectively), VMP was lowest at 82%. A smaller initial ratio, but a lower overall contrast level (4-19-19% contrast), resulted in a higher VMP of 91.5%. As the priming contrast ratios decreased to 1:4 or less, irrespective of overall contrast level, VMP quickly asymptoted.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1994
- Accession Number
- ADA284782
Entities
People
- Alan R. Pinkus
Organizations
- Armstrong Laboratory