Effect of 19" vs 17" monitor on stimuli?

[jarvis24]

[edited from support email]

I have a rather random question for you about MediaLab and DirectRT. One of the monitors has been replaced in our computer lab and the replacement is 19" rather than 17". Tanya was wondering whether this might create a problem for parafovial priming studies. When a stimulus is programmed to be presented parafovially, is the distance from the center fixed or is it a ratio of screen width? I just want to make sure there won't be a difference between what participants will see based on the monitor being used.

[jarvis24]

The important thing is the screen resolution. To see the effects directly, take an 800x600 picture and display it full screen with the display set at 800x600. If you are running 800x600 pixels on a 19", the pixels will consume more area than they do on a 17" monitor.

So the short answer to you question is that, given the same display resolution, your stimuli will spread out in proportion to the screen size. So if a fixed distance is important to you (and it sounds like it is) then you will need to calibrate your stimuli in terms of size and placement which going to a bigger or smaller monitor.

Hope that helps,
Blair