Keypress and timer recording delay

Getting Started
1

Quick summary:

Trying to use xojo to run scientific research, I am trying to record a person’s response time when an image is shown. I’ve set up some code to have a timer start recording when the image is shown and end when a person has pressed a button. This is repeated 1000 times with some intermittent pauses gated by button presses and timer slideshows. Point is, when I am look at people’s performances, I am noticing gaps in times recorded (e.g., no responses from 300-370 milliseconds) but large recorded times at 371 milliseconds. My working hypothesis is that there are some pockets of delay that the computer does not register a button press and then records this action at the next available moment. No code is written to produce these events.

Here is a visual.

image
image758×366 18 KB

Can someone fill me in on what is going on please? Broad stroke explanations would also be happily accepted. Essentially, I am trying to figure out if is a coding issue or some computer-code compatibility (it is a 2013 desktop mac I believe)?

2

Which event are you launching the timer from - KeyDown or KeyUp?

3

KeyDown

4

Have you tried moving that to key up as there should be some milliseconds worth of delay as the key has to come up after it has been pressed.

  • Move your code to the KeyUp Event
  • Then add Return True under your KeyDown event (which will fire the KeyUp event)

Hope this helps.

Mike

PS Welcome to the Xojo Forum @Jong_Han_Lee1

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5

Why use a timer? Record the Milliseconds when the image is displayed and again in KeyDown. Subtract the two. I think the timer is introducing at least part of the issue.

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