I need to generate 2 BOLD-response signals in an even-related experiment. I know that I should generate a vector of 0 and 1 (1 for onsets) and then convolve with hrf. But in my situation, I need to have 2 signals with a certain correlation. How can I generate 2 BOLD-response signals with a certain correlation in an event-related experiment?

Best 

Suzanne