[visionlist] Data projector pixel decay times

[Deborah Apthorp]

Hi all,

I'm normally a psychophysicist, but am about to embark on some fMRI 
work. I'm very new to all this, but was surprised to learn that it's 
usual to use an LCD projector with nominal 60Hz refresh rate to present 
stimuli in the scanner. Since I plan to do motion experiments, I'm 
rather concerned about the decay times on the projector and I need to 
know how long it will be before something I draw onto the screen will 
disappear. I gather that CRT monitors (which we usually use in the lab) 
have a phosphor decay of between 2 & 4 ms - I know the projector will be 
slower, but does anyone know exactly how much slower?

The projector is an NEC LT 158, if that is useful to know.

I'd greatly appreciate it if anyone has data on this.

Thanks,

Deborah Apthorp
(University of Sydney, Australia)