psychopy.org | Reference | Downloads | Github

Text presentation in a flashing mode

Hi, I am building a simple block design paradigm in builder. I want to present a letter on the screen for 30 second but get it to flash every 3 seconds rather than be static for the whole 30 second. I am new to builder and Psychopy and have no idea how to do this. Can anyone help please?

This depends a little on how your trial routine is conducted. For example, if it suits, you could create a routine which is 6 seconds in duration, with the text stimulus only visible for the first 3 seconds (or less, your description above is ambiguous). You then enclose the routine in a loop which runs 5 times. That loop needs to have its “Is trials” setting as “False”. i.e. this loop runs within a trial, and is likely nested inside your main trials loop.

That sort of repetition might not suit your other stimuli and response collection however. In that case, you can insert a code component and put in a little snippet of code that controls the visibility of the stimulus on a frame-by-frame basis of the entire, single, 30 s trial.

To do that, you need to define a little more precisely what you mean by “flash every 3 seconds”.

Thank you. I have solved the problem by setting up a loop just for the flash, so it shows the stimuli for 3 seconds followed by 0.5 s blank screen. And then another loop to repeat this however many times I want. It seems to work but I am not sure if it was the best way of doing it. Hopefully it does not matter.