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Can DirectRT Present Subliminal Images?

  1. #1

    Can DirectRT Present Subliminal Images?

    I am working on a research project for my undergraduate degree in honors psychology at North Carolina State University. I'm trying to measure the effects of subliminal messages on decision making.

    For some time, I have been attempting to construct a video file with images spliced in. These images have to be presented so fast that subjects are unaware of them. Approximately, I am aiming for 1/22,000 sec...

    I have tried all the major video editing software I can get my hands on, and have come up with nothing.

    Is DirectRT and MediaLab capable of making such a video file?

  2. #2
    Hm - DirectRT can handle subliminal messages; however the output being used must be able to handle rendering each frame that quickly. For rendering images at a 120 Hz refresh rate, I would recommend the following monitor:
    http://www.newegg.com/Product/Product.aspx?Item=N82E16824001311

    Common monitors will output at 60 Hz, meaning they will render at 60 frames a second, or rather (1000/60) 1 frame per 16.67 milliseconds. A monitor with a 120 Hz refresh rate similar to the one above will render at 120 frames a second, or (1000/120) 1 frame per 8.33 milliseconds.

    DirectRT cannot create a video with the output you've noted; however it can run experiments at just about any timing resolution - as long as the monitor being used has a high enough refresh rate to handle the refresh rate required by your experiment. MediaLab is not capable of this, as it doesn't use the actual refresh rate of the monitor to specify when stimuli are drawn to the screen.