Unwanted/unprogrammed blank/black screen and button press? (case 16706)

I've programmed my stimuli to appear and disappear as planned but when I ran the .csv file, from time to time a blank/black screen would show up, and it wouldn't go away unless I pressed the space bar. In my programming, I do have a black image (that creates the visual effect of a complete blank screen since the background for all other image stimuli is black) in a stimuli list .txt file among other images, and if it works properly, the black image will be randomly presented and will disappear automatically in 1500 ms. All other images I programmed in my study appear and disappear on cue... I can't figure out why the blank screen doesn't. Any help would be highly appreciated.

Thanks in advance!

Please upload a copy of your .csv input file and tell me exactly in it where the unwanted blank screen that doesn't go away unless you press the space bar appears. I'll be happy to take a look at it.

Hi Jason, here's the .csv file. However, I can't tell you exactly where in the file the unwanted blank screen shows up. It shows up randomly. Sometimes at the beginning of a block, and sometimes as the 3rd trial, and sometimes as the 7th trial, etc. One thing that might help is that the only .txt file that contains "blank.bmp" in the stimlist is the "filler_cc" file. Please let me know if you need any other information from me.

Thanks!

[QUOTE=jason_reed;21137]Please upload a copy of your .csv input file and tell me exactly in it where the unwanted blank screen that doesn't go away unless you press the space bar appears. I'll be happy to take a look at it.[/QUOTE]

By the way, is there a limit for how long the image file name can be? Or other restrictions for image file names...? Thanks!

Run your DirectRT input file without any randomization (make all values in the brg and wgr columns 0). Let me know when in that kind of file the black screen pops up so that we can pinpoint where it is in the file.


Please also send me copies of your stimfiles and point out which of the entries in it is the black image file.


Finally, I am not aware of any limits on the image file names, but I personally tend to keep them as simple and short as possible. I would also avoid using nonalphanumeric characters (e.g., &, _, etc.) at the beginning of DirectRT file names to avoid confusion when using them in the .csv input files

Hi Jason, I changed all the values in bgr and wgr columns to 0. I still can't figure out the pattern of the images that actually appear. Most of the time the screen was blank/black. Some images in the stimlists did appear, but because the screen was blank most of the time, I couldn't tell you at exactly which trial each image appeared. The images that did appear are "f_fb2_bugs_size" "f_fb1_0t_size" from the fcc_size.txt, "1b1t_centerp" from target1.txt, "1b2t_blk_p" from target2.txt, "f_ade_milk_close" "f_ade_milk_close" "f_fb5_mush_close" from fcc_close.txt, and "f_atr_smo" from filler_cc.txt. Of course the images that are not randomly selected from a stimlist (i.e., the ones that I manually filled in) appeared correctly.

Of all the stimlist files I'm attaching here, only the filler_cc.txt contains black image - there are 11 entries at the end of the list called "blank." They are referring to the black.bmp image.

Let me know if you need any other information from me. Thanks!

PS: I edited all the pictures and the .txt files and programmed the .csv file on a Mac computer and then copied and pasted all the picture files, .txt files, and the .csv files to a Windows computer to run the experiment with DirectRT... if that makes any difference.

Hi Jason, good news! I figured out what went wrong with my experiment. It's working now. Thanks for all your help!

Your're welcome. What did you do to fix your input file?

When I was creating the stimlist, I copied the name of the images one by one and pasted them to the .txt. For some reason, the names I copied and pasted were not in plain text format. That's why DirectRT did not recognize the image files in the stimlist. After I manually typed each name of the image into all the stimlists, the experiment worked as expected. :)

Thanks for the information!