Freezing between trials


I’m currently trying to program an experiment on Superlab 4.0, however there seems to be a freezing problem between trials.

Each block of my experiment (15 blocks in total) consists of 8 trials, each containing 360 JPEG files (a lot, I know) with a cue superimposed throughout. The 360 JPEG events are each displayed for a 16ms, resulting in the appearance of a continually spinning object (120 images result create one complete spin).

The events within a single trial run smoothly, however I was expecting the transitions between trials to be smooth also - this does not appear to be the case…

As opposed to the object continually spinning for the duration of the experiment between blocks and trials, there is a 4 second freeze between trials in which Superlab is unresponsive - even if I press escape, it waits until the next trial has begun. On top of this issue, which is literally doubling the length of the experiment, the software takes approximately 5 minutes to start running it!

I’ve experimented with the memory management option (i.e. loading all files before or between trials) but to no avail. Also, it doesn’t seem to be a problem related to the memory of the PC as I can multi-task during the running of the experiment, i.e. to operate explorer, etc. As such, I’m stuck as to how to resolve, or improve, this issue…

Any ideas anyone?


SuperLab does a lot of housekeeping in-between trials, for example, loading files from disk, allocating memory for them, and so forth. Additionally, JPEG files need to be decompressed. Further, once the trial is over, SuperLab needs to deallocate memory and other resources. You can reduce the 4 second “freeze” by loading all files before. This will work only if you have A LOT of RAM in your case. You can also reduce the 4 second delay by converting your JPEG files to BMP files, but it will not be possible to completely eliminate this delay.