OS (e.g. Win10): Windows 7
PsychoPy version (e.g. 1.84.x): 1.83.04
Standard Standalone? (y/n) If not then what?: y
What are you trying to achieve?: Parallel-port signals should be sent at specific words during word-by-word sentence presentation.
I want to present the words of a sentence for 300 ms with a blank screen for 200 ms between each word. The sentences, which vary in length, are read from an external excel-file.
In a Code-component in my Trial I use this code in the Begin Routine-tab. Note that I used number of frames instead of time to display the word (18 frames) and the blank inter-stimulus-interval (12 frames).
# get the sentence for this trial and split it into a list of words: words = sentence.split() # count them (the length of the list): numWords = len(words) # how long the text component should display for: totalDuration = 0.001 + (numWords * 0.5) # time in seconds # loop to display the word followed by a blank: for word in words: text_15.setText(word) #set current word in Builder placeholder text variable for frameN in range (18): text_15.draw() #present current word for 18 frames (at 60Hz!) win.flip() for frameN in range(12): #present blank screen for 12 frames (at 60Hz!) win.flip()
The presentation as such seems to work just fine.
However, I want to send a parallel port-signal that is different for every sentence at the onset of certain words. Therefore, the position of the words (trig_w1, trig_w2) and the respective signal-to-be-sent (trig_1, trig_2) are also in the excel-file.
What did you try to make it work?:
My idea was to create a frame counter in the Begin routine-tab (note that the examples below serve only to illustrate my idea, they never worked as desired), such as
# frame counter: frame_counter = 0
and update it in the Each frame-tab
# update the frame counter with each frame: frame_counter = frame_counter + 1
To keep track of the word that is being displayed, I thought of something like this in the Each frame-tab
# which word is displayed current_word = frame_counter / 30 # because each word+ISI is displayed for 30 frames
If the current word is one that I want to send a trigger at, the respective code is sent through something like this:
if current_word == trig_w1: p_port.setData(trig_1)
What specifically went wrong when you tried that?:
Since the loop to present the sentence word by word is in the Begin routine-tab, the frame counter in the Each frame-tab doesn’t work. It seems that the code in the Each frame-tab is executed only after the loop in the Begin routine-tab is finished.
I am aware that there is some other flaws in the examples above. However, I wonder if this approach does work at all. I am completely new to python-programming, so I don’t dare to make a judgment of this and I am pretty lost with going on from here.
Thank you for your help!