Change text presented onscreen after every keypress

Builder
1

OS: Win 10
Version: 2020.2.10
Standard Standalone: yes

I’m trying to develop a task in which a number is presented onscreen, and participants have to make a judgement about it (e.g. odd or even?) and press a response key. Once they press the key, the number should be replaced by a new (randomly drawn) number, and so on. This should continue for a pre-determined amount of time (e.g. 5 seconds), no matter how many responses they make. Ideally this should all be enclosed within one routine.

So far I have a simple routine set up with a code segment code, a text stim number, and a key press resp_1, shown below. Note that the Text field of number is defined as $rand_value, and it has a duration of 5.0 seconds. Also note that Force end of Routine is unchecked in resp_1

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EDIT: I have changed number to “set every frame” instead of “set every repeat”

The Begin Routine tab of code contains a line which generates a random value to be shown onscreen at the start of the trial.

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In the Each Frame tab, I used the following to try and reset rand_value following each button press

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This doesn’t cause any errors, but the first generated number (I assume from the Begin Routine tab) simply displays onscreen for 5 s and does not change, regardless of key presses. I need it to change with every key press, but I can’t figure out how to do that.

Any advice would be greatly appreciated!

2

I am not sure about the code, but it seems that your text component is set to update “every repeat”, it should be set to update “every frame” to work

3

Ah, good point! I’ve made that change…hasn’t fixed the issue, but it was probably a necessary first step!

4

Then instead of using a keyboard component, try implementing a keyboard response in the code component, like:

#In the each frame tab
myKeyPress = event.getKeys('return') #you can swap "return" for any key
if 'return' in myKeyPress: # when RETURN is pressed 
     #write here the code to change the text
5

It works!! Thanks so much!

For future users, the code I used to change the text was: rand_value = random.randint(0,100). Therefore, the full segment in the “Each Frame” tab looks like:

myKeyPress = event.getKeys('return') 
if 'return' in myKeyPress:
    rand_value = random.randint(0,100)

…but note that you still need to have rand_value = random.randint(0,100) in the “Begin Routine” tab. If you need to add multiple keys (e.g. left and right) I found that the following works (as an alternative to the above segment):

myKeyPress = event.getKeys(['left','right']) 
if 'left' in myKeyPress:
    rand_value = random.randint(0,100)
elif 'right' in myKeyPress:
    rand_value = random.randint(0,100)