[solved] how to use one interval screen with several durations
Hello everyone,
We're trying to program a reaction time task for our thesis. Our task is very simple, a dot is being showed and the participant has to press the spacebar as quick as possible. However we're facing a problem. We want the interval between the dots being showed randomly to range from 2.2 seconds to 3 seconds and each dot is being presented untill a keypress response. We're not sure how to do this. Can we make one intervalscreen which can be presented with different durations ranging from 2.2 seconds to 3 seconds or do we have to make several intervalscreens?
Comments
Hi,
Two options:
Fixed delay amounts
Add a new variable to your loop, e.g. called "delay". Refer to this variable for the duration of your sketchpad, using square brackets: [delay].
Random delay
There is a plug-in built into OpenSesame to do precisely this. It's called the
advanced_delay. Your experiment could look as follows:# start of your experiment - loop (for the trial blocks) - sequence (for a single trial) - blank sketchpad (duration of 0) - advanced delay (see below for details) - sketchpad showing a dot (duration of 0) - keyboard_responseNow for the advanced delay: it requires two values: the average delay, and the jitter. Furthermore, you have to indicate the type of jitter. In you case, you want values to occur equally between 2.2 and 3 seconds, so set the jitter mode to uniform. The average duration should be 2600 ms, and the jitter should be 400 ms. This gives you values between 2600-400 ms (= 2.2 seconds) and 2600+400 ms (= 3 seconds).
Good luck!
Hi Edwin,
We used your first option. Thank you very much.