Running multiple participants at once?

[I][edited from support email][/I]

I'm very interested in your DirectRT software, but could not establish from your site whether it would allow the creation of a test for several participants simultaneously or whether it would support video stimuli.

To explain, I'm looking for a programme - requiring minimal programming code knowledge - that will help me create a test for more than one person at a time. I need to show a series of stimuli (ideally video-based) and record each person's decision and reaction time - that is, four or five people have to make a 'yes' or 'no' decision to each stimulus (using keypads connected to a USB hub) and the test only progresses when the last person has made their choice on the current stimulus.

Is this something DirectRT could help me create? It is not a crucial part of the project to have video-based stimuli (auditory would be less preferable but still acceptable), so I'm not too concerned if it does not support this, but I do need to record the reaction times and decisions of five participants simultaneously.

Showing video is not a problem at all. In fact, this study could probably be done quite easily. The trick would be to get the screen display sent to 5 monitors simultaneously. I expect the hardware exists for that but you'd have to find it. I'll ask our hardware engineer if he knows what that would take. After that, you just need a series of keyboards or other input devices (button boxes, mice) connected to that same system. Easiest way would be via a USB hub. DirectRT has a function that will allow you to require a defined number of keystrokes. The challenge here would be to figure out which keystroke is coming from which participant. One way would be to assign different keys to each subject. Another way would be to use button boxes that send different values. We make, for example, button boxes with a single button. We could make 10 of them for you such that each one sent a different value. One would represent "yes" and the other "no" for each participant. Voilà. Anyways, that's off the top of my head, but bottom line is that I do think it's probably doable.

Assuming you're showing the same video image to all five people, I'd search for something called a 'VGA Splitter' or 'VGA Distribution Amplifier.'

The folks who handle your campus A/V installations may even have something lying on the shelf you could use. Sometimes these are available for short or long term rental from Audio/Visual supply houses.

If you're buying, price starts at a few hundred dollars and goes up from there, depending on the available outputs.

Basically it takes the output from your computer and splits it multiple times for different displays.

It's the same sort of box used in the furniture stores when they want to show the same football game on an entire wall of television sets.

As Blair mentioned above, we can also help you with a set of custom button boxes. These would allow responses from all five participants to be recorded discretely.

John