Present one event from a choice of three

Hi All,

Probably a simple question but I cannot figure out how to do it. I wish to present one set of instructions from a choice of three. However, I would like superlab to randomly decide which event to present and one present one of these before the task begins. The difference between the instructions is the picture in the background (therefore the instructions are saved as a picture file).

I hope someone can help as soon as possible.

Thanks in advance

Create a block and connect it to three trials. Each trial should connect to one “instructions” picture event. Then, under the block level create an expression under the When to Run tab. The expression should be, “Number of Trials Presented in This Block is Equal to 0”. Still within the When to Run tab, select “While the condition expression is true” next to Present the trials in the block. You will also randomize under the block level.