Methods used during Phase 1 data collection were as follows:
- Mean luminance = 30 cd/m^2 +- 5
- Frame rate >= 60 Hz
- Grayscale resolution: < 0.25 threshold
- 2IFC or Rating psychophysical procedure
- Binocular viewing
- Natural pupils
- Time course of each stimulus should be a Gaussian with a standard deviation of 0.125 sec and a total duration of 0.5 sec.
- 120 pixels/degree raster resolution
- image size = 256 x 256 pixels
- Fixation marks = 2 pixel x 12 pixel "L" shaped corner marks just outside the 256x256 pixel stimulus field
- Feedback provided
- Enough trials to achieve expected standard errors of less than 0.1 log unit.
- Thresholds reported should represent estimate of 84% correct point.