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Failure to achive short presentation times

Hey everyone! I’m building a time sensitive experiment and I can’t seem to go below 40ms image presentation time.

my experiment goes as follows:
fixation[500ms] --> target image(drawn randomly from picture folder) [17ms] --> mask [500ms] --> response collection

My knowledge of insuffiecent presentation time came from using the following codes:
*globalClock.reset() – at the begin routine
*thisExp.addData(‘time’,str(globalClock.getTime())) - the end routine

The thing I’m trying to achieve is 17ms target image presentation time. I’m using Psychopy
version 3.1.5 on Windows 10 and I have 60hz monitor.

I’ve tried changing the image duration parameters endlessly yet neither using the seconds or frames parameter seems to achieve my goal.

All aid will be met with joy and cookies! :yum:

E.

Hi,

Your code isn’t currently measuring the duration of presentation, but the duration of the routine, which aren’t necessarily the same thing.

To present an image file for only one screen refresh while also reading it in from disk and processing it is challenging. So you should schedule that importing to happen during the fixation period, so it is ready prior to your intended presentation time:

Insert a “static period component” that overlaps with your fixation period. Now in your image component, you’ll see that the name of that static period is available as an option for when the image should be updated. i.e. change the image field from updating “every repeat” to the option that has the name of your new static period.

With that arrangement, a single frame display duration should be feasible.

Thank you so much Michael!

Now I can finally present my image for a single frame duration :smile:

Cookies are on their way :stuck_out_tongue:

E.