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ErwinHaasnoot / QRTEngine

Qualtrics Reaction Time Engine (QRTEngine) is an extension to Qualtrics which allows researchers, but generally any who are interested, to easily build behavioural online experiments.
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Syncronous presentation? #37

Closed stephensrmmartin closed 9 years ago

stephensrmmartin commented 9 years ago

Hello again,

I'd love to run a subliminal priming study via qrtengine. The problem is that we would like to present one stimulus for about 16-18 ms.

Whether the stimulus is drawn on the screen that quickly depends on the refresh rate (and response time of the pixel change) of the monitor.

I know there is a way via the dom standard to synchronize animations via window.requestAnimationFrame, and there are pages that can estimate a monitor's refresh rate (e.g., http://www.vsynctester.com/detect.html). Is there any way to present the stimulus in a manner that is synchronized with the monitor refresh?

It's a longshot, but it would ensure that everyone sees the stimulus as clearly and as consistently as possible.

stephensrmmartin commented 9 years ago

Ha... never mind. I just read the white paper and it says you all use rAF already.

Perhaps it is merely a problem on my very old laptop.