staircase

I want to implement a simple staircase procedure. I have a series of blocks of trials that get progressively more difficult. Using macros at the block level, I can implement a 3-down, 1-up staircase, so that if the participant gets 3 trials correct the experiment goes to the next hardest block, and each time a response is incorrect the experiment goes to the next easiest block.

However, my problem comes in how to end the experiment. Typically a staircase procedure should end after a certain number (say 10) of reversals or changes in difficulty level. In my case, after a certain number of transitions between blocks. How can I implement this is Superlab 4.5?

More specifically, the options for setting expressions seem very limited (i.e, “Time since start of block/experiment, trials presented in this block”). It seems that I need some flexibility to tell Superlab that I want to track the number of reversals…

Thanks for any help.

This is fairly easy to do in SuperLab 5, but it cannot be done in SuperLab 4.5. Within SuperLab 5 you can create a parameter of type Counter and increment by 1 every time you have a reversal. Then you would exit the experiment when the Counter reaches 10.