event marker for large number of stimuli


I’m trying to build an experiment in which the subjects will listen to and answer 200 questions while fixating their gazes on an image displayed by a computer screen, and their pupil diameters will be measured continuously by ASL through out the experiment. I’m using Measurement Computing PCI-DIO24 to send digital signal from Superlab to the ASL system.

This is what I need and I couldn’t figure out a good way to do it:

  1. An fixation image is displayed through out the experiment.
  2. Markers at the beginning and the end of each audio sentence;
    3, A marker for each response (I’m using RB-530 keypad);
  3. Sentences are randomized for each subject.

Thanks for the help in advance!

Help needed!


Could any of you help me with this?

I have two trials, and each trial has two event markers (mark onset and offset of a sentence) and a stimuli list (6 sentences). I don’t think I built the experiment correctly because the stimuli list will play 6 sentences successively and I only got markers at the beginning and the end of the list instead of each sentence. What is the correct way?

I’ve attached my experiment. Looking forward to your advice!

Thanks very much for your time!


Event marker test.zip (3.32 MB)

I have ran your experiment and it seems to work as you described it should: onset, followed by audio, followed by offset.

I have attached a modified version of the experiment. What I did was change the event type for your offset and onset events from Digital Output to Text, and set a time limit of 200msec. This helped me see what the onset and offset visually.

Note that there is a little bit of silence at the beginning of each audio file. If you press the keys too fast, the experiment will look like it’s doing nothing but present onsets and offsets — the audio will be interrupted during the silence period and will appear to never have played.

Event marker test rev B.sl5 (8.95 KB)

Thanks very much! I didn’t realize the trial does pull out one event from the stimuli list at a time. The stimuli list is really a good tool.

Thanks again!