User`s guide

E-Prime User’s Guide
Appendix D: Display Presentation
Page A-56
after the pixel has been refreshed, the pixel will decay for another few milliseconds, and the
retinal activation will persist for substantially longer unless it is masked by another stimulus.
0 50 100 150 200 250 300 350
Time (ms)
Activation
Slide
Display
Raster
Display
Raster Based
Visual Activation
Slide Based
Visual Activation
Visual Integration
Figure 2. Time course of the raster display, and visual integration of the raster display on each scan.
Figure 2 also shows a comparison of presenting material with a slide shutter projector or
tachistoscope relative to a computer monitor. The lines labeled Slide Display and Slide Based
Visual Activation show the activity that would be produced if the total display intensity were
continuous as opposed to pulsating (i.e., like the refreshes of a computer monitor). The total
visual energy of the Slide and Raster activation have been matched. Note the similarity of the
activation functions
23
. For the subject, there is no perceptible difference. For a detailed
discussion of these issues, see Busey & Loftus, Psychology Review, 1994, 101, 446-469.
23
In the simulation the slide display was delayed by 2ms and the raster by 7ms. This produces functions
that have matching increases in activation within a few percent from 50ms until the termination of the
display. These differences are insignificant in terms of human perception (see Busey & Loftus 1994). In
Figure 2, the decay of the activation for the Slide Display was somewhat slower than the Raster Display due
to the last refresh of the Raster Display not being displayed as a result of clearing video memory 200ms
after the write to video memory but rather than 200ms after the first display of the video.