[solved] How do I uncouple stimulus duration time and keybord response time? URGENT

wrappy89

Hello,
we are three students from Germany and currently designing an experiment. After presentation of a face stimulus for 150ms, the participant has to indicate by keybord response if the face was happy or sad. We would like to have a keybord response time of 2000ms. The problem is that OpenSesame presents the stimulus as long as the 2000ms we enter into the "duration" field of the keybord response settings. So our question is how we uncouple these two elements.
We would be so thankful for help!

eduard

Hi,

What is happening here is that the keyboard element doesn't change anything that happens on the screen. Therefore, after the stimulus was presented for 150 ms, the screen waits in an idle state for the next update and only "accidentally", so to speak. So to fix it, you need to present something else, e.g. an empty screen, right after the stimulus, before you wait for the response. As this extra screen takes also some time, you should have the keyboard duration reduced to some degree. So, if you present the empty screen for 100ms, your keyboard duration should be set to 1900.

Does this make sense?

Eduard