Multiple images from stim lists

[mfaulkner]

Good Afternoon,


I am a student at American University in the Busse Lab. I am currently creating an input file, and I have been unsuccessful in one aspect of the file. I want to have a picture appear on the screen and have a word appear "BIKE". I then want the picture to remain on the screen, while the word "BIKE" changes colors randomly. I want the word to vary from blue, green, and red randomly. When the blue word appears, the participant will strike the valid key and the next screen will appear. I want each trial will be conducted this way. Is there a way I can do this, because I have been unsuccessful.

[jarvis24]

The easiest way to do that would to be to create your words as graphics--each the same size. Place the names of those images in a stim file and draw them randomly on each trial. This would be done by listing them as sequential stimuli, e.g., $word, $word, $word, in the case that you have three coloured word images. Make sure that in the location (LOC) column of each that you use a clear value of "0", e.g., ".75,.5,0" if you want the words to appear three quarters of the way down the screen and centered horizontally. The final "0" value is the clear value and tells DirectRT to preserve whatever is on the screen when it displays the picture. Since the word pictures are all the same size, each will overwrite the other but the remainder of the screen will appear constant--i.e., your origional picture will remain onscreen the whole time.

Finally, to have the words change automatically, use a "!" in the min-max value for the style you are applying to the trial. For example, to have the words switch every 500ms, use a min-max value of "0-500!"

How you proceed from there will depend on whether or not you want them to see all the colours or if you want the trial to end if and when they respond.

Hope that helps,
Blair

[mfaulkner]

I tried this and it did not work. I created the words as bmp files and saved them. When I attempted to place them in a stim file (I used the stim file provided, which was empty) they appeared but, when I entered the file name (as sequential stimuli, $Slide1, $Slide2, etc) the words $Slide1 appeared and not the image.

I already created the input file and just need this piece to be placed into the input file. I am not sure what I'm doing wrong or if I need to create a new file all together. Any help you can provide would be greatly appreciated.

[jarvis24]

Can you zip the folder into a single file and attach it here or send it to support@emp...? I'll take a look and see if I can tell what's wrong.

[mfaulkner]

Thank you for all your help I have attached the zip folder and it contains only the experiment (just a shortcut & the file).



Monica

[jarvis24]

Not sure what's going on without seeing the image or stim list files. Try the revision I've attached and see if that helps. Also, try taking any path info out of your stimlist files. e.g., Instead of something like:

C:\Documents and Settings\Monica\...\stim1
C:\Documents and Settings\Monica\...\stim2

Just use:

stim1
stim2

Also, make sure all your stimuli and stimlists are located in the Stim folder that is located in the same folder as your input file.

If that doesn't help you, try zipping and attaching your stim folder.