My lab has been using Superlab connected to a Biopac MP-150 data acquisition system to run an oddball ERP study where participants press a button in response to an auditory stimulus. The way our Superlab experiment is set up, for each trial, a digital pulse is generated and then the stimulus is supposed to be played 25 ms later. However, when we look at the digital pulses recorded by the MP-150, the time between each pulse varies from trial to trial. Our concern is that there may be some variation in the delay between the pulse and the stimulus presentation within trials that would make it impossible for us to know exactly when the stimuli were presented. Is there any way for us to find out whether the time between the digital pulse and the stimulus presentation is being delayed or varying from trial to trial? The experiment is attached.
I’ve been trying to find out why this delay is happening, and one thing I noticed is that, when I ran this experiment and checked the Task Manager, the CPU usage was up around 95-99%. The computer that is running Superlab is a Dell Inspiron laptop with an Intel Core 2 Duo 2 GHz processor and 2 GB of RAM. The computer has Windows Vista and our version of Superlab is 4.0.7b. I read in another post that audio files tend to take more processing power – is it possible that our computer just isn’t up to the hardware requirements of this kind of task?
3.oddball_new.sl4 (65.1 KB)