Stimuli speeds

SuperLab SuperLab 4 Support
1

Hello

I have created an experiment using jpeg files, which are displayed as a slide show with a 5000 millisecond delay. There is no response required, and the stimuli change automatically after the timed delay.

For some reason, on a laptop the experiment displays the stimuli extremely fast, ie less that 1000millieseconds each. Where as the same experiment works perfectly on another computer.

Is there any reason for this?

Thank you

2

The only reason coming to mind is that you may not have an input device enabled. Depending on how the experiment is set up, if there’s no input device selected, SuperLab will run through an experiment very quickly.

Do both computers have the same version of SuperLab installed? (e.g. 4.0.4) Are they both the same platform? (Mac vs. Windows)

3

Hi Hank

Thanks for the response.

We are using v4.03 at the moment, but it was the same version installed on the laptop and computers and both had a windows platform.

I had also adjusted the experiment to have an input device and then removed the option to see if that made a difference, but the timing on the laptop was still alot faster than we had a set it to be.

4

It sounds like it’s not the input device, considering that it’s happening on only one machine. Also, since it’s working fine on your other machine, I have a suspicion that I wouldn’t be able to duplicate the issue if you sent me the experiment (I might, though).

We can get more information about what’s going on if we look at the verbose log. This hidden feature was introduced in SuperLab 4.0.3. Directions for how to enable this are included here for Windows and here for Mac OS X. This spits out a very large amount of information in a window after you’ve run your experiment. Between this output and the experiment itself, we should be able to figure out what’s going on.

5

Thanks you for the information Hank.

We have recreated the experiment on another PC and used that now.

Unfortunately, my colleague had uninstalled the Superlab from the Laptop before i was able to look at teh Verbose Log.

Thanks anyway

6

We’ve looked at many of the issues raised in our rsearch on millisecond timing accuracy. In short you’re right to check and keep on checking! We’ve now an all-in-one commercial device called the Black Box ToolKit which will do this kind of check more easily and accurately. For information on our published papers, the kit and who’s using it see:

http://www.blackboxtoolkit.com/

Unfortunately the issue of timing inaccuracy isn’t going away any time soon regardless of how fast your PC or MAC etc. is or what experiment generator you use :frowning:

Richard