Generating an Experiment Script in E-Prime
Q: When I generate the script, no error comes up. When I try to run the experiment, however, an error occurs with sound files and I can never get to the end of the experiment. The instruction page appears fine. But whenever it has to play certain sound files, it keeps showing me the same error message: “Run-time error 18005: Cannot load sound file “xxx.wav”. Mismatched or invalid channels.” I made sure the E-Studio file and sound files used in the experiment are in the same folder as the experiment itself. I listed the names of sound files correctly in E-Studio with “.wav” extension. And of course, I turned on the sound device in E-Studio.
A: If you’ve already added the sound device (and turned it on), you’ll have to adjust the channels and check the format of the sound files. Be sure to use mono (rather than stereo files) I think in the sound device area there should be an option regarding sample rate of the audio (44,000 Hz is default, 22,000 Hz or something like that is what we use). Either you didn’t change that in E-prime, or the sound files were not sampled down to 22,000 Hz when they were edited in Sound Studio (or whatever sound editing software you’re using). If you can get through some of the experiment before the error comes up, this would suggest that there are some files that are incorrectly formatted (e.g. were not sampled down to 22,000 Hz). Check the run script to determine at what point in the script the problem presents.
Instructions for merging individual subject data files (edats) into a single file
Q: I can’t get the data files for individual subjects (edat) to merge into a single file. Please tell me I don’t have to cut and paste them all!
A. Oh yes, we can do better than cutting and pasting- be sure to merge files properly by using E-Merge
- Make sure all .edat and .txt files from the subjects you want to merge are in the same folder.
- Open E-Merge.
- Within the directory select the folder containing the data files you want to merge.
- Select all the files to be merged, then hit ‘merge’ (check ‘simple’ not ‘recursive’).
- Once you name this file and merge you can close E-Merge
- Open .emrg file and export to excel (sometimes need to convert to .txt before .xlsx)
Correcting display of warped images
Q. I’m trying to present images with very specific configurations and they appear warped in the E-Prime display. I tried saving the files in different sizes, but no matter what I do they look misshapen in E-Prime. Help?
A. Try changing the screen resolution within E-Prime
Edit > Experiment > Device tab > Display
General troubleshooting – When everything used to work but no longer does
Q. My script worked in the past, and though I don’t think I’ve changed anything, now E-Prime won’t run and gives an error message. Help meeee.
A. Be sure the E-Prime key (a physical bit of hardware you plug into the USB port) is plugged into the computer. This is, essentially, your license, and the way E-Prime keeps us paying tribute 😉
Still doesn’t work? Check to see that your stimuli are still in the proper folder so that the path you’ve used in the script doesn’t need to be updated.
Still doesn’t work? Yeah- sounds like you’re in trouble. Let us know how you resolve the problem, and we’ll add it to this page. Good luck!
~Much gratitude to Valentin Lazar and Jee Young Kim for contributions to this page and for making our experiments run smoothly!
Logging responses in Presentation
Q. Some or all of the subjects button-press responses are not being registered by the system, or do not show up in the logs.
A: This usually arises because the response buttons need to be defined (and often redefined if any changes are made to the script). To make sure all of your desired response buttons will be read in by the system, go to the ‘settings’-> ‘responses’-> and select each button you’d like to use. Within this window, you can then test to see that each key press is acknowledged by the system. Note that responses made using a button box will typically be read in as either 1,2,3,4 (where there are 4 buttons) and sometimes even A,B,C,D. For example- in an fMRI experiment, the scanner trigger pulse might show up (e.g. as a ‘5’ response in your logfile), but not the button box responses from the subject. Such a log output would indicate a need to (re)define the buttons accepted as input during the experiment.